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Bridging the Pacific provides an image of two separate regions which share the Pacific Rim, becoming connected in multiple aspects, not limited to a predominantly economic interconnection. This image, thus, points toward a constructive mechanism to work toward a resolution of the over-arching global issue, including climate change. This image and the method for its practical implementation are suggested by the Forum for East Asia and Latin America Cooperation—FEALAC. In the overall field of regionalism studies, inter-regionalism can be considered as 'the third wave' under the new regionalism, and FEALAC can be located in this analytical framework. To begin, this paper traces the process and features of regionalism by typification of three different versions, or ideal types of regionalism. In this work, each type of regionalism is not viewed as a successor to, considered better than the previous one, but rather provides a typology for analytical purposes. Next, taking up this historical and analytical framework of regionalism, this paper examines the FEALAC in terms of its strengths and weaknesses considered from the perspective of the five systemic functions. Finally, this paper demonstrates the ways in which FEALAC can be considered a relevant framework of inter-regional governance. [ABSTRACT FROM AUTHOR]

During the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) project an extensive dataset of all halogen species relevant for the atmospheric budget of total organic bromine has been collected in the West Pacific region using the FALCON aircraft operated by the German Aerospace agency DLR (Deutsches Zentrum für Luft- und Raumfahrt) covering a vertical range from the planetary boundary layer up to the ceiling altitude of the aircraft of 13 km. In total, more than 700 measurements were performed with the newly developed fully-automated in-situ instrument GHOST-MS (Gas cHromatograph for the Observation of Tracers - coupled with a Mass Spectrometer) by the Goethe University of Frankfurt (GUF) and with the onboard whole-air sampler WASP with subsequent ground based state-of-the-art GC/MS analysis by the University of East Anglia (UEA). Both instruments yield good agreement for all major (CHBr3 and CH2Br2) and minor (CHBrCl, CHBrCl2 and CHBr2Cl) VSLS (very short-lived substances), at least at the level of their 2 s measurement uncertainties. In contrast to the suggestion that the Western Pacific could be a major source region for VSLS (Pyle et al., 2011), we found only slightly enhanced mixing ratios of brominated halogen source gases relative to the levels reported in Montzka et al. (2011) for other tropical regions. A budget for total organic bromine, including all four halons,CH3Br and the VSLS, is derived for the upper troposphere, the input region for the TTL and thus also for the stratosphere, compiled from the SHIVA dataset. With exception of the two minor VSLS CHBrCl2 and CHBr2Cl, excellent agreement with the values reported in Montzka et al. (2011) is found, while being slightly higher than previous studies from our group based on balloon-borne measurements. [ABSTRACT FROM AUTHOR]

This paper describes the Comprehensive Pacific Rainfall Database (PACRAIN), which contains daily and monthly precipitation records from the tropical Pacific basin. The database is a collection of observations from a variety of sources, including one, the Schools of the Pacific Rainfall Climate Experiment (SPaRCE), that is unique to PACRAIN. SPaRCE is a cooperative field project and involves schools from various Pacific island and atoll nations. Recent enhancements to the database, including improved quality control, observation and data entry standardization, expansion of the network, increased collaboration with local meteorological directors, and enhanced high-resolution data (e.g., on hourly or minute time scales), are discussed. This paper also outlines some of the internal data and Web-based access specifics of the database. To illustrate the potential usefulness of the data, two examples of research using the PACRAIN database are provided and discussed. The first is an analysis of temporal changes in the extreme event characteristics of daily precipitation across the region. The second is an illustration of how the PACRAIN database can be used to analyze satellite-based precipitation algorithms. [ABSTRACT FROM AUTHOR]

This article derives from an interview with Dr. Rÿser conducted by Zoltán Grossman on October 5, 2009. It was published in the book Asserting Native Resilience: Pacific Rim Indigenous Nations Face The Climate Crises, edited by Zoltan Grossman and Alan Parker, and released in 2012. In this essay, Dr. Rÿser comprehensively explores the role indigenous sovereignty plays in addressing the challenges posed by climate change. Emphasizing the importance of traditional knowledge and governance structures in fostering environmental resilience and effective adaptation strategies, he highlights the critical need for indigenous peoples to assert their authority as regulators and standard-setters in the face of climate change. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change is impacting human survival through its impact upon water quality and availability. An urgent ethical imperative is thus raised for education policy makers and schools, particularly in the Australian and Asia Pacific regions, to adopt a curriculum to help students mitigate and adapt to the dire consequences caused by a warming planet. Through a blue transdisciplinary school curriculum, students will better understand and respond to the broader aspects of what is referred to as the hydrosocial cycle. A school move towards a blue curriculum requires educational policy to mandate an emphasis on the climate change effects upon the water cycle. An effective shift to a blue curriculum also requires that teachers' ethical perspectives and sensitivities are sharpened through their tertiary education courses. This is needed so they develop confidence and pedagogy for teaching anthropogenic climate change generally, something still missing from Australian and other classrooms around the world, and, more specifically, for teaching the hydrosocial cycle. The Four Component Model of Ethical Decision Making is offered as a useful framework to guide teachers in examining their values and motivations when teaching potentially confronting topics such as the impacts of climate change upon the hydrosocial cycle. [ABSTRACT FROM AUTHOR]

In the context of the imperative global shift towards renewable energy to mitigate climate change, Latin America (LATAM) emerges as a region of immense untapped potential. However, there is no formal quantification of the effects of developing this potential. This study analyzes the economic and climate impacts of developing renewable energy in LATAM and the Asia–Pacific region using an integrated economic and climate assessment model (IAM). The key findings are as follows. First, exporting renewable energy from LATAM and the Asia–Pacific region yields economic benefits across all regions. However, this surge in renewable energy exacerbates rather than alleviates global warming. Second, the implementation of policy measures accompanying renewable energy exports, aimed at discouraging the use of polluting energy sources, proves effective in mitigating global warming while sustaining significant economic gains globally. Third, LATAM stands to gain substantially from this development. Fourth, due to the gradual process of capital accumulation, any delays in initiating the development of renewable energy exports not only diminish economic gains during the postponement but also in the years following the commencement of exports. These results are robust to several additional simulations and sensitivity analyses. The results align with the goals of the Paris Agreement. [ABSTRACT FROM AUTHOR]

The years 2014 and 2015 turned out to be quite catastrophic for the Asia-Pacific region which took a major toll on the socioeconomic stature of all the entities of the region. The agricultural sector which is one of the most contributing factors to the economy of the region has been highly sensitive to the global climatic changes. Hence this endeavor shall greatly help in an efficient prediction of monsoon cycles, thus enabling the hapless farmers to be better informed and avoid major losses of any kind. The paper focuses on the climatology of air temperature and MSLP with the variation pattern in precipitation over the Asia-Pacific region. The NCEP-NCAR reanalysis data is used for air temperature and MSLP along with high-resolution precipitation dataset for Asia-Pacific monsoon region obtained from GPCP. The temperature datasets are analyzed up to the level 500 hPa. Monte Carlo method of correlation and Bootstrapping method of confidence interval are used to analyze the relation of GPCP with MSLP and temperature at all defined levels. So, in this paper authors attempt to assess the nature and relationship of temperature and MSLP to precipitation over the Asia-Pacific region with the recent 10-year changes which are quantified in detail. [ABSTRACT FROM AUTHOR]

A hybrid coupled model (HCM) is constructed for El Niño-Southern Oscillation (ENSO)-related modeling studies over almost the entire Pacific basin. An ocean general circulation model is coupled to a statistical atmospheric model for interannual wind stress anomalies to represent their dominant coupling with sea surface temperatures. In addition, various relevant forcing and feedback processes exist in the region and can affect ENSO in a significant way; their effects are simply represented using historical data and are incorporated into the HCM, including stochastic forcing of atmospheric winds, and feedbacks associated with freshwater flux, ocean biology-induced heating (OBH), and tropical instability waves (TIWs). In addition to its computational efficiency, the advantages of making use of such an HCM enable these related forcing and feedback processes to be represented individually or collectively, allowing their modulating effects on ENSO to be examined in a clean and clear way. In this paper, examples are given to illustrate the ability of the HCM to depict the mean ocean state, the circulation pathways connecting the subtropics and tropics in the western Pacific, and interannual variability associated with ENSO. As satellite data are taken to parameterize processes that are not explicitly represented in the HCM, this work also demonstrates an innovative method of using remotely sensed data for climate modeling. Further model applications related with ENSO modulations by extratropical influences and by various forcings and feedbacks will be presented in Part II of this study. [ABSTRACT FROM AUTHOR]

Highlights • Nonindigenous species (NIS) spread risk is evaluated at the country level. • Opening of the Arctic shipping routes increases the risk of NIS spread to the U.S. • China is the riskiest trade partner in the Asia-Pacific region for the U.S. • Asia-Pacific tropical countries present small increased NIS spread risk to the U.S. Abstract This paper estimates the impacts of future Arctic shipping on the risk of terrestrial and aquatic nonindigenous species (NIS) spread to the U.S. east coast from various Asian countries. We consider two components of risk – introduction and establishment. Risk of introduction is based on economic modeling predictions of changes in trade flows from future opening of Arctic shipping. Risk of establishment given successful introduction is based on climate similarities determined by an environmental model. We estimate total NIS spread risk as the product of introduction and establishment risks. Results highlight risk profiles for key U.S. trade partners in Asia and show that NIS spread risk to the U.S. east coast is highest from China and Japan. Shipments from Hong Kong and the Philippines present nominal increased species spread risk to the U.S. given low levels of terrestrial and marine climate similarity and minor expected trade changes between the two regions. [ABSTRACT FROM AUTHOR]

This is the first of two articles on the steepening challenges which confront global agriculture, food security and hence nutrition and population health. The recent deterioration in global food security has caught most experts by surprise. While the Asia Pacific region as a whole has so far fared reasonably well, there should be no complacency about medium to long term food security in the region, whether or not food security improves in the near future. The first paper places this debate in the context of the long-standing arguments between Malthusianists and optimists. The apparent reversal of position in the last decade of two leading agricultural experts is discussed. Their recent writings reflect intensified Malthusian concerns curbed in their writings from the 1990s. The paper concludes that far more credence needs to be given to the pessimistic position in order to avoid it becoming reality. The second paper focusses on five interrelated challenges to future food security in the Asia Pacific. These may be conceptualised as pathways by which pessimistic Malthusian scenarios become manifest. The mechanisms are (1) climate change. (2) water scarcity, (3) tropospheric ozone pollution. (4) impending scarcity of phosphorus and conventional oil and (5) the possible interaction between future population displacement, conflict and poor governance. The article concludes that a sustainable improvement in food security requires a radical transformation in society's approach to the environment, population growth, agricultural research and the distribution of rights, opportunities and entitlements. [ABSTRACT FROM AUTHOR]

The impact of clouds and precipitation on the climate is a strong function of their spatial distribution and microphysical properties, characteristics that depend, in turn, on the environments in which they form. Simulating feedbacks between clouds, precipitation, and their surroundings therefore places an enormous burden on the parameterized physics used in current climate models. This paper uses multisensor observations from the Tropical Rainfall Measuring Mission (TRMM) to assess the representation of the response of regional energy and water cycles in the tropical Pacific to the strong 1998 El Niño event in (Atmospheric Model Intercomparison Project) AMIP-style simulations from the climate models that participated in the Intergovernmental Panel on Climate Change’s (IPCC’s) most recent assessment report. The relationship between model errors and uncertainties in their representation of the impacts of clouds and precipitation on local energy budgets is also explored. With the exception of cloud radiative impacts that are often overestimated in both regions, the responses of atmospheric composition and heating to El Niño are generally captured in the east Pacific where the SST forcing is locally direct. Many models fail, however, to correctly predict the magnitude of induced trends in the west Pacific where the response depends more critically on accurate representation of the zonal atmospheric circulation. As a result, a majority of the models examined do not reproduce the apparent westward transport of energy in the equatorial Pacific during the 1998 El Niño event. Furthermore, the intermodel variability in the responses of precipitation, total heating, and vertical motion is often larger than the intrinsic ENSO signal itself, implying an inherent lack of predictive capability in the ensemble with regard to the response of the mean zonal atmospheric circulation in the tropical Pacific to ENSO. While ENSO does not necessarily provide a proxy for anthropogenic climate change, the results suggest that deficiencies remain in the representation of relationships between radiation, clouds, and precipitation in current climate models that cannot be ignored when interpreting their predictions of future climate. [ABSTRACT FROM AUTHOR]

This paper explores changes in the principal components of observed energy budgets across the tropical Pacific in response to the strong 1998 El Niño event. Multisensor observations from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), Visible and Infrared Scanner (VIRS), and precipitation radar (PR) instruments aboard TRMM are used to quantify changes in radiative and latent heating in the east and west Pacific in response to the different phases of the El Niño–Southern Oscillation. In periods of normal east–west SST gradients there is substantial heating in the west Pacific and cooling in the east, implying strong eastward atmospheric energy transport. During the active phase of the El Niño, both the east and west Pacific tend toward local radiative–convective equilibrium resulting in their temporary energetic decoupling. It is further demonstrated that the response of these regions to ENSO-induced SST variability is directly related to changes in the characteristics of clouds and precipitation in each region. Through quantitative analysis of the radiative and latent heating properties of shallow, midlevel, and deep precipitation events and an equivalent set of nonprecipitating cloud systems, times of reduced atmospheric heating are found to be associated with a shift toward shallow and midlevel precipitation systems and associated low-level cloudiness. The precipitation from such systems is typically less intense, and they do not trap outgoing longwave radiation as efficiently as their deeper counterparts, resulting in reduced radiative and latent heating of the atmosphere. The results also suggest that the net effect of precipitating systems on top-of-the-atmosphere (TOA) fluxes and the efficiency with which they heat the atmosphere and cool the surface exhibit strong dependence on their surroundings. The sensitivity of cloud radiative impacts to the atmospheric and surface properties they act to modify implies the existence of strong feedbacks whose representation may pose a significant challenge to the climate modeling community. [ABSTRACT FROM AUTHOR]

Antifreeze proteins (AFPs) inhibit ice growth within fish and protect them from freezing in icy seawater. Alanine-rich, alpha-helical AFPs (type I) have independently (convergently) evolved in four branches of fishes, one of which is a subsection of the righteye flounders. The origin of this gene family has been elucidated by sequencing two loci from a starry flounder, Platichthys stellatus, collected off Vancouver Island, British Columbia. The first locus had two alleles that demonstrated the plasticity of the AFP gene family, one encoding 33 AFPs and the other allele only four. In the closely related Pacific halibut, this locus encodes multiple Gig2 (antiviral) proteins, but in the starry flounder, the Gig2 genes were found at a second locus due to a lineage-specific duplication event. An ancestral Gig2 gave rise to a 3-kDa "skin" AFP isoform, encoding three Ala-rich 11-a.a. repeats, that is expressed in skin and other peripheral tissues. Subsequent gene duplications, followed by internal duplications of the 11 a.a. repeat and the gain of a signal sequence, gave rise to circulating AFP isoforms. One of these, the "hyperactive" 32-kDa Maxi likely underwent a contraction to a shorter 3.3-kDa "liver" isoform. Present day starry flounders found in Pacific Rim coastal waters from California to Alaska show a positive correlation between latitude and AFP gene dosage, with the shorter allele being more prevalent at lower latitudes. This study conclusively demonstrates that the flounder AFP arose from the Gig2 gene, so it is evolutionarily unrelated to the three other classes of type I AFPs from non-flounders. Additionally, this gene arose and underwent amplification coincident with the onset of ocean cooling during the Cenozoic ice ages. [ABSTRACT FROM AUTHOR]

This is the second of two articles on challenges to future food security in the Asia Pacific region. It focuses on five mechanisms, which can be conceptualised as pathways by which pessimistic Malthusian scenarios, described in the first paper, may become manifest. The mechanisms are (1) climate change, (2) water scarcity, (3) tropospheric ozone pollution, (4) impending scarcity of phosphorus and conventional oil and (5) the possible interaction between future population displacement, conflict and poor governance. This article concludes that a sustainable improvement in food security requires a radical transformation in society's approach to the environment, population growth, agricultural research and the distribution of rights, opportunities and entitlements. [ABSTRACT FROM AUTHOR]

An atmospheric general circulation model (AGCM) is forced with patterns of observed sea surface tem- perature (SST) change and those output from atmosphere--ocean GCM (AOGCM) climate change simula- tions to demonstrate a strong dependence of climate feedback on the spatial structure of surface temperature change. Cloud and lapse rate feedbacks are found to vary the most, depending strongly on the pattern of tropical Pacific SST change. When warming is focused in the southeast tropical Pacific--a region of clima- tological subsidence and extensivemarine lowcloud cover--warming reduces the lower-tropospheric stability (LTS) and lowcloud cover but is largely trapped under an inversion and hence has little remote effect. The net result is a relatively weak negative lapse rate feedback and a large positive cloud feedback. In contrast, when warming is weak in the southeast tropical Pacific and enhanced in the west tropical Pacific--a strong con- vective region--warming is efficiently transported throughout the free troposphere. The increased atmo- spheric stability results in a strong negative lapse rate feedback and increases the LTS in low cloud regions, resulting in a low cloud feedback of weak magnitude. These mechanisms help explain why climate feedback and sensitivity change on multidecadal time scales in AOGCM abrupt4xCO2 simulations and are different from those seen in AGCM experiments forced with observed historical SST changes. From the physical understanding developed here, one should expect unusually negative radiative feedbacks and low effective climate sensitivities to be diagnosed from real-world variations in radiative fluxes and temperature over decades in which the eastern Pacific has lacked warming. [ABSTRACT FROM AUTHOR]

Pacific Island communities are increasingly experiencing the impacts of climate change. Inaccessibility to relevant information about contemporary climate change adaptation strategies at the community level presents challenges. At the same time, indigenous strategies to adapt to climate changes have been overlooked in both local and global climate change debates. This article discusses a project undertaken with a community in Andra Island, Manus Province, Papua New Guinea. Climate change impacts and adaptation strategies were explored through photo essays developed by community members, engaging in approaches of visual participatory action research and indigenous research approaches. The collaboration with the Andra Island community created a space for reflective dialogue about challenges posed by climate change as well as how photo essays can be used to promote Indigenous Knowledge (IK) as a viable capital for community-based adaptation (CBA). Within this context, this article demonstrates how climate change is both a natural and cultural process of change which poses socio-economic challenges. These challenges can compel people to engage in unsustainable practices that might exacerbate natural climate change impacts. The article highlights that building community capacity in participatory media can be an important tool to forge collective synergy, dialogue and ownership in local climate change initiatives. In particular, the authors demonstrate how participatory media can be harnessed to integrate indigenous knowledge in community-based climate change adaptation. [ABSTRACT FROM AUTHOR]

The mass media in the Asia Pacific region are reporting the environmental disasters that are regularly hitting the planet, religiously, and journalists learn as they go along. However, the reporting has focused mainly on the toll in human lives and property. This is disaster reporting and it stops short of contextualising. It does not adequately explain why the environmental disasters are happening more violently and more frequently. Not too many reporters have taken formal courses in environmental journalism. Only a very few schools are offering regular courses, or programmes in science and environmental reporting, as indicated by a mini-survey in July 2016. The vacuum in formal science and environmental education is being filled by non-government organisations offering non-formal training. [ABSTRACT FROM AUTHOR]

Background: Between 2010 and 2012, the World Health Organization Division of Pacific Technical Support led a regional climate change and health vulnerability assessment and adaptation planning project, in collaboration with health sector partners, in 13 Pacific island countries -- Cook Islands, Federated States of Micronesia, Fiji, Kiribati, Marshall Islands, Nauru, Niue, Palau, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu. Objective: We assessed the vulnerabilities of Pacific island countries to the health impacts of climate change and planned adaptation strategies to minimize such threats to health. Methods: This assessment involved a combination of quantitative and qualitative techniques. The former included descriptive epidemiology, time series analyses, Poisson regression, and spatial modeling of climate and climate-sensitive disease data, in the few instances where this was possible; the latter included wide stakeholder consultations, iterative consensus building, and expert opinion. Vulnerabilities were ranked using a "likelihood versus impact" matrix, and adaptation strategies were prioritized and planned accordingly. Results: The highest-priority climate-sensitive health risks in Pacific island countries included trauma from extreme weather events, heat-related illnesses, compromised safety and security of water and food, vector-borne diseases, zoonoses, respiratory illnesses, psychosocial ill-health, noncommunicable diseases, population pressures, and health system deficiencies. Adaptation strategies relating to these climate change and health risks could be clustered according to categories common to many countries in the Pacific region. Conclusion: Pacific island countries are among the most vulnerable in the world to the health impacts of climate change. This vulnerability is a function of their unique geographic, demographic, and socioeconomic characteristics combined with their exposure to changing weather patterns associated with climate change, the health risks entailed, and the limited capacity of the countries to manage and adapt in the face of such risks. Citation: McIver L, Kim R, Woodward A, Hales S, Spickett J, Katscherian D, Hashizume M, Honda Y, Kim H, Iddings S, Naicker J, Bambrick H, McMichael AJ, Ebi KL. 2016. Health impacts of climate change in Pacific island countries: a regional assessment of vulnerabilities and adaptation priorities. Environ Health Perspect 124:1707-1714; http://dx.doi.org/10.1289/ehp.1509756 [ABSTRACT FROM AUTHOR]

El Niño-Southern Oscillation (ENSO) is one of the most important drivers of climatic variability on the global scale. Much of this variability arises in response to ENSO-driven changes in tropical Pacific rainfall. Previous research has shown that the ENSO-driven tropical Pacific rainfall variability can shift east and intensify in response to global warming, even if ENSO-related SST variability remains unchanged. Here, the twenty-first century changes in ENSO-driven tropical Pacific rainfall variability in 32 CMIP5 models forced under the representative concentration pathway 8.5 (RCP8.5) scenario are examined, revealing that the pattern of changes in ENSO-driven rainfall is not only gradually enhanced but also shifts steadily eastward along with the global-mean temperature increase. Using a recently developed moisture budget decomposition method, it is shown that the projected changes in ENSO-driven rainfall variability in the tropical Pacific can be primarily attributed to a projected increase in both mean-state surface moisture and spatially relative changes in mean-state SST, defined as the departure of local SST changes from the tropical mean. The enhanced moisture increase enlarges the thermodynamic component of ENSO rainfall changes. The enhanced El Niño-like changes in mean-state SST steadily move the dynamic component of changes in ENSO-driven rainfall variability to the central-eastern Pacific, along with increasing global-mean temperature. [ABSTRACT FROM AUTHOR]

Based on the historical and RCP8.5 runs of the multi-model ensemble of 32 models participating in CMIP5, the present study evaluates the formation mechanisms for the patterns of changes in equatorial Pacific SST under global warming. Two features with complex formation processes, the zonal El Ni˜no-like pattern and the meridional equatorial peak warming (EPW), are investigated. The climatological evaporation is the main contributor to the El Ni˜no-like pattern, while the ocean dynamical thermostat effect plays a comparable negative role. The cloud-shortwave-radiation-SST feedback and the weakened Walker circulation play a small positive role in the El Ni˜no-like pattern. The processes associated with ocean dynamics are confined to the equator. The climatological evaporation is also the dominant contributor to the EPW pattern, as suggested in previous studies. However, the effects of some processes are inconsistent with previous studies. For example, changes in the zonal heat advection due to the weakened Walker circulation have a remarkable positive contribution to the EPW pattern, and changes in the shortwave radiation play a negative role in the EPW pattern. [ABSTRACT FROM AUTHOR]

Merremia peltata is a species with uncertain status in the island nations of the Pacific region. It has been designated introduced and invasive in some countries whereas it is considered native in others. Recent increase in its abundance across some island landscapes have led to calls for its designation as an invasive species of environmental concern with biological control being suggested as a control strategy. Climate change will add to the complications of managing this species since changes in climate will influence its range limits. In this study, we develop a process-oriented niche model of M. peltata using CLIMEX to investigate the impacts of climate change on its potential distribution. Information on the climatic requirements of M. peltata and its current geographic distribution were used to calibrate the model. The results indicate that under current climate, 273,132 km2 of the land area in the region is climatically unsuitable or marginal for M. peltata whereas 664,524 km2 is suitable to highly suitable. Under current climate, areas of climatic suitability for M. peltata were identified on the archipelagos of Fiji, Papua New Guinea, Solomon Islands and Vanuatu. By the end of the century, some archipelagos like Fiji, Hawaii, New Caledonia and Vanuatu will probably become more suitable while PNG and Solomon Islands become less suitable for M. peltata. The results can be used to inform biosecurity planning, management and conservation strategies on islands. [ABSTRACT FROM AUTHOR]

The article discusses measures taken by New Zealand to protect people from humanitarian disaster and to manage out-migration due to climatic change in Pacific Region. Topics discussed include policies made by New Zealand to train migrants such as voluntary migration schemes, recognized seasonal employer scheme and labor-training migration schemes, limitations of international laws to protect migrants, and provision made by the United Nations to protect migrants.

While scientific evidence in support of climate change is growing, awareness and education about its effects, especially among vulnerable communities, is lacking, due to language and cultural barriers. Communities are unlikely to respond to government policies promoting mitigation and adaptation strategies without an improved perception of climate change risk at a local level. Mapping the flow of information between decision makers and citizens is an important part of this process. This article broadly explores the communication channels that are being used for awareness and knowledge sharing in the Pacific. At its core, the article discusses a way in which participatory media has been piloted to enable community discussion about issues around climate change in the Pacific Islands. The 'bottom-up' approach encourages participation of marginalised groups such as women, youth, and people with disabilities who bring diverse perspectives in content creation. This discursive space enables citizens to share knowledge and acquire better understanding of the impacts on livelihood and culture. However, a strong community network and consistent mentoring support are prerequisites for participatory media to have long term benefits. [ABSTRACT FROM AUTHOR]

While climate change has global causations and impacts, there is growing consensus on addressing the 2 °C challenge through local actions. However, at the local level, there is disintegrated knowledge on the following: (a) short-, mid- and long-term climate vulnerability, (b) economy and GHG structures and their future pathways, and (c) useful mitigation and adaptation undertaken elsewhere. We evaluate these gaps through a comprehensive review of scientific literature and policy approaches of urban-climate studies in the Asia-Pacific Region. Based on the research findings, we develop a collaborative research framework of an integrated climate action planning (ICLAP) model for evidence-based decision-making tool. It adopts an innovative methodology integrating knowledge and data from diverse analytics, as follows: (a) spatial: downscaling global/regional climate scenarios to forecast local climate variability (50 km × 50 km) for 2030 (SDG target) and 2050; (b) statistical: a meta-analysis of 49 five-million-plus cities to forecast economic, energy and GHG scenarios; (c) bibliometric: a systematic review of global urban climate interventions from Google Scholar that collectively aid cities on policy inputs for mid-term climate variability, GHG profiles and available solutions at their disposal. We conclude with a discussion on scientific and policy relevance of such a tool in fostering overall urban, regional and global sustainability. [ABSTRACT FROM AUTHOR]

A recently developed technique for simulating large [0(104)] numbers of tropical cyclones in climate states described by global gridded data is applied to simulations of historical and future climate states simulated by six Coupled Model Intercomparison Project 5 (CMIP5) global climate models. Tropical cyclones downscaled from the climate of the period 1950-2005 are compared with those of the 21st century in simulations that stipulate that the radiative forcing from greenhouse gases increases by 8.5 W.m-2 over pre-industrial values. In contrast to storms that appear explicitly in most global models, the frequency of downscaled tropical cyclones increases during the 21st century in most locations. The intensity of such storms, as measured by their maximum wind speeds, also increases, in agreement with previous results. Increases in tropical cyclone activity are most prominent in the western North Pacific, but are evident in other regions except for the southwestern Pacific. The increased frequency of events is consistent with increases in a genesis potential index based on monthly mean global model output. These results are compared and contrasted with other inferences concerning the effect of global warming on tropical cyclones. [ABSTRACT FROM AUTHOR]

The eastern tropical Pacific (ETP) is believed to be one of the largest marine sources of the greenhouse gas nitrous oxide (N2O). Future N2O emissions from the ETP are highly uncertain because oxygen minimum zones are expected to expand, affecting both regional production and consumption of N2O. Here we assess three primary uncertainties in how N2O may respond to changing O2 levels: (1) the relationship between N2O production and O2 (is it linear or exponential at low O2 concentrations?), (2) the cutoff point at which net N2O production switches to net N2O consumption (uncertainties in this parameterisation can lead to differences in model ETP N2O concentrations of more than 20%), and (3) the rate of net N2O consumption at low O2. Based on the MEMENTO database, which is the largest N2O dataset currently available, we find that N2O production in the ETP increases linearly rather than exponentially with decreasing O2. Additionally, net N2O consumption switches to net N2O production at ~10 µM O2, a value in line with recent studies that suggest consumption occurs on a larger scale than previously thought. N2O consumption is on the order of 0.01-1 mmol N2Om-3 yr-1 in the Peru-Chile Under-current. Based on these findings, it appears that recent studies substantially overestimated N2O production in the ETP. In light of expected deoxygenation and the higher than previously expected point at which net N2O production switches to consumption, there is enough uncertainty in future N2O production that even the sign of future changes is still unclear. [ABSTRACT FROM AUTHOR]

To better understand the causes of climate change in the tropical Pacific on decadal and longer time scales, the authors delineate the rectification effect of ENSO events into the mean state by contrasting the time-mean state of a low-order model for the Pacific with its equilibrium state. The model encapsulates the essential physics of the ENSO system, but remains simple enough to allow for the obtaining of its equilibrium state. The model has an oscillatory regime that resembles the observations. In this oscillatory regime, the time-mean SST in the eastern equatorial Pacific is found to be significantly different from the corresponding equilibrium SST, with the former being warmer than the latter. The difference is found to be proportional to the amplitude of ENSO. In addition, the zonal SST contrast of the time-mean state is found to be less sensitive to increases in external forcing than that of the equilibrium state, due to warming effect of ENSO events on the eastern Pacific. It is further shown that this rectification effect of ENSO events results from the nonlinear advection term in the heat budget equation. The study elucidates the role of ENSO events in shaping the tropical mean climate state and suggests that decadal warming in the recent decades in the eastern tropical Pacific may be more a consequence than a cause of the elevated ENSO activity during the same period. The results also provide a simple explanation for why it is difficult to detect an anthropogenically forced trend in the zonal SST contrast in the observations. [ABSTRACT FROM AUTHOR]

By analyzing a set of the Coupled Model Intercomparison Project phase 3 (CMIP3) climate model projections of the twenty-first century, it is found that the shallow meridional overturning of the Pacific subtropical cells (STCs) show contrasting trends between two hemispheres in a warming climate. The strength of STCs and equivalently the STC surface-layer transport tend to be weakening (strengthening) in the Northern (Southern) Hemisphere as a response to large-scale surface wind changes over the tropical Pacific. The STC pycnocline transport convergence into the equatorial Pacific Ocean from higher latitudes shows a robust weakening in the twenty-first century. This weakening is mainly through interior pathways consistent with the relaxation of the zonal pycnocline tilt, whereas the transport change through western boundary pathways is small and not consistent across models. It is found that the change of the western boundary pycnocline transport is strongly affected by the shoaling of the pycnocline base. In addition, there is a robust weakening of the Indonesian Throughflow (ITF) transport in a warming climate. In the multimodel ensemble mean, the response to greenhouse warming of the upper-ocean mass balance associated with the STCs is such that the weakening of the equatorward pycnocline transport convergence is balanced by a weakening of the poleward surface-layer transport divergence and the ITF transport of similar amounts. [ABSTRACT FROM AUTHOR]

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The probability of climate extremes is strongly affected by atmospheric circulation. This study quantifies the worldwide influence of three major modes of circulation on station-based indices of intense precipitation: the El Niño--Southern Oscillation, the Pacific interdecadal variability as characterized by the North Pacific index (NPI), and the North Atlantic Oscillation--Northern Annular Mode. The study examines which stations show a statistically significant (5%%) difference between the positive and negative phases of a circulation regime. Results show distinct regional patterns of response to all these modes of climate variability; however, precipitation extremes are most substantially affected by the El Niño--Southern Oscillation. The effects of the El Niño--Southern Oscillation are seen throughout the world, including in India, Africa, South America, the Pacific Rim, North America, and, weakly, Europe. The North Atlantic Oscillation has a strong, continent-wide effect on Eurasia and affects a small, but not negligible, percentage of stations across the Northern Hemispheric midlatitudes. This percentage increases slightly if the Northern Annular Mode index is used rather than the NAO index. In that case, a region of increase in intense precipitation can also be found in Southeast Asia. The NPI influence on precipitation extremes is similar to the response to El Niño, and strongest in landmasses adjacent to the Pacific. Consistently, indices of more rare precipitation events show a weaker response to circulation than indices of moderate extremes; the results are quite similar, but of opposite sign, for negative anomalies of the circulation indices. [ABSTRACT FROM AUTHOR]

Interannual sea surface temperature (SST) variability in the central equatorial Pacific consists of a component related to eastern Pacific SST variations (called Type-1 SST variability) and a component not related to them (called Type-2 SST variability). Lead–lagged regression and ocean surface-layer temperature balance analyses were performed to contrast their control mechanisms. Type-1 variability is part of the canonical, which is characterized by SST anomalies extending from the South American coast to the central Pacific, is coupled with the Southern Oscillation, and is associated with basinwide subsurface ocean variations. This type of variability is dominated by a major 4–5-yr periodicity and a minor biennial (2–2.5 yr) periodicity. In contrast, Type-2 variability is dominated by a biennial periodicity, is associated with local air–sea interactions, and lacks a basinwide anomaly structure. In addition, Type-2 SST variability exhibits a strong connection to the subtropics of both hemispheres, particularly the Northern Hemisphere. Type-2 SST anomalies appear first in the northeastern subtropical Pacific and later spread toward the central equatorial Pacific, being generated in both regions by anomalous surface heat flux forcing associated with wind anomalies. The SST anomalies undergo rapid intensification in the central equatorial Pacific through ocean advection processes, and eventually decay as a result of surface heat flux damping and zonal advection. The southward spreading of trade wind anomalies within the northeastern subtropics-to-central tropics pathway of Type-2 variability is associated with intensity variations of the subtropical high. Type-2 variability is found to become stronger after 1990, associated with a concurrent increase in the subtropical variability. It is concluded that Type-2 interannual variability represents a subtropical-excited phenomenon that is different from the conventional ENSO Type-1 variability. [ABSTRACT FROM AUTHOR]

A “perfect model” configuration with a global coupled climate model 30-member ensemble is used to address decadal prediction of Pacific SSTs. All model data are low-pass filtered to focus on the low-frequency decadal component. The first three EOFs in the twentieth-century simulation, representing nearly 80% of the total variance, are used as the basis for early twenty-first-century predictions. The first two EOFs represent the forced trend and the interdecadal Pacific oscillation (IPO), respectively, as noted in previous studies, and the third has elements of both trend and IPO patterns. The perfect model reference simulation, the target for the prediction, is taken as the experiment that ran continuously from the twentieth to twenty-first century using anthropogenic and natural forcings for the twentieth century and the A1B scenario for the twenty-first century. The other 29 members use a perturbation in the atmosphere at year 2000 and are run until 2061. Since the IPO has been recognized as a dominant contributor to decadal variability in the Pacific, information late in the twentieth century and early in the twenty-first century is used to select a subset of ensemble members that are more skillful in tracking the time evolution of the IPO (EOF2) in relation to a notional start date of 2010. Predictions for the 19-yr period centered on the year 2020 use that subset of ensemble members to construct Pacific SST patterns based on the predicted evolution of the first three EOFs. Compared to the perfect model reference simulation, the predictions show some skill for Pacific SST predictions with anomaly pattern correlations greater than +0.5. An application of the Pacific SST prediction is made to precipitation over North America and Australia. Even though there are additional far-field influences on Pacific SSTs and North American and Australian precipitation involving the Atlantic multidecadal oscillation (AMO) in the Atlantic, and Indian Ocean and South Asian monsoon variability, there is qualitative skill for the pattern of predicted precipitation over North America and Australia using predicted Pacific SSTs. This exercise shows that, in the presence of a large forced trend like that in the large ensemble, much of Pacific region decadal predictability about 20 years into the future arises from increasing greenhouse gases. [ABSTRACT FROM AUTHOR]

The coupled model of the Institute of Atmospheric Physics (IAP) is used to investigate the effects of extratropical cooling and warming on the tropical Pacific climate. The IAP coupled model is a fully coupled GCM without any flux correction. The model has been used in many aspects of climate modeling, including the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) climate change and paleoclimate simulations. In this study, the IAP coupled model is subjected to cooling or heating over the extratropical Pacific. As in an earlier study, the cooling and heating is imposed over the extratropical region poleward of 10°N–10°S. Consistent with earlier findings, an elevated (reduced) level of ENSO activity in response to an increase (decrease) in the cooling over the extratropical region is found. The changes in the time-mean structure of the equatorial upper ocean are also found to be very different between the case in which ocean–atmosphere is coupled over the equatorial region and the case in which the ocean–atmosphere over the equatorial region is decoupled. For example, in the uncoupled run, the thermocline water across the entire equatorial Pacific is cooled in response to an increase in the extratropical cooling. In the corresponding coupled run, the changes in the equatorial upper-ocean temperature in the extratropical cooling resemble a La Niña situation—a deeper thermocline in the western and central Pacific accompanied by a shallower thermocline in the eastern Pacific. Conversely, with coupling, the response of the equatorial upper ocean to extratropical cooling resembles an El Niño situation. These results ascertain the role of extratropical ocean in determining the amplitude of ENSO. The results also underscore the importance of ocean–atmosphere coupling in the interaction between the tropical Pacific and the extratropical Pacific. [ABSTRACT FROM AUTHOR]

This article reflects upon how gendered approaches to climate-change adaptation can be strengthened in the Pacific region. The article looks at what has been learnt in the region, surveys some examples of best practice in gender-responsive programming, identifies the challenges we face on our journey, and suggests future directions. It is a collaborative effort, comprising input from a number of agencies who have been proactive in the areas of gender, climate change, and disaster risk-reduction in the Pacific Region, including: the Red Cross/Red Crescent Movement in the Pacific region; the UNDP Pacific Centre; and World Wildlife Fund's (WWF) Fiji Country Programme. [ABSTRACT FROM AUTHOR]

The authors argue that a reduction to the stochastic forcing of the El Niño–Southern Oscillation (ENSO) wrought by Pacific-wide climate changes in response to mid-Holocene (6000 BP) orbital forcing is a viable hypothesis for the observed reduction of ENSO activity during that time. This conclusion is based on comprehensive analysis of an intermediate coupled model that achieves significant reduction to ENSO variance in response to mid-Holocene orbital forcing. The model's excellent simulation of the tropical Pacific interannual variability lends credibility to the results. Idealized simulations demonstrate that the mid-Holocene influence is communicated to the tropical Pacific largely via climate changes outside of the tropical Pacific, rather than from insolation changes directly on the tropical Pacific. This is particularly true for changes to the ENSO, but also with changes to the cold tongue annual cycle. Previously proposed mechanisms for teleconnected mid-Holocene ENSO changes, including forcing of ENSO by a strengthened Asian summer monsoon and an increase in the annual cycle forcing on the tropical Pacific leading to a reduction in ENSO activity by frequency entrainment, do not appear to occur in these simulations. Rather, the authors show that the modeled mid-Holocene climate exhibits a pronounced reduction in Pacific meridional mode activity that has been recently shown to be a forcing on ENSO, though the reasons for this reduction are still to be explained. The contrasting nature of the results compared to previous studies highlights the effect of the prevailing ENSO paradigm on this problem. By showing that an externally forced ENSO model is equally capable of explaining mid-Holocene ENSO reduction as its nonlinear, weakly chaotic counterpart, it is demonstrated that the mid-Holocene ENSO data point cannot yet discriminate between these two paradigms of ENSO. [ABSTRACT FROM AUTHOR]

Aim To assess the genetic and archaeological evidence for the migration of modern humans out of Africa to the circum-Pacific region and compare the migration patterns with Late Pleistocene and Holocene changes in sea level and climate. Location Southern and eastern Asia, Australia, and Oceania. Methods Review of the literature and detailed compilations of data on early human settlements, sea level, and climate change. Results The expansion of modern humans out of Africa, following a coastal route into southern Asia, was initially thwarted by a series of large and abrupt environmental changes. A period of relatively stable climate and sea level from c. 45,000 yrbp to 40,000 yrbp supported a rapid coastal expansion of modern humans throughout much of Southeast Asia, enabling them to reach the coasts of northeast Russia and Japan by 38,000–37,000 yrbp. Further northwards, migrations were delayed by cold northern climates, which began to deteriorate rapidly after 33,000 yrbp. Human migrations along the coast of the Bering Sea into the New World appear to have occurred much later, c. 14,000 yrbp, probably by people from central Asia who were better adapted to cold northern climates. Cold, dry climates and rapidly changing sea levels leading into and out of the Last Glacial Maximum inhibited coastal settlement, and many of the sites occupied prior to 33,000 yrbp were abandoned. After 16,000 yrbp, the sea-level rise slowed enough to permit coastal ecosystems to develop and coasts to be re-colonized, but abrupt changes in climate and sea level inhibited this development until after 12,000 yrbp. Between 12,000 yrbp and 7000 yrbp there was a dramatic increase in reef and estuary/lagoon ecosystems, concurrent with a major expansion of coastal settlements. This early Holocene increase in coastal environments and the concomitant expansion of human coastal-resource exploitation were followed by corresponding declines in both phenomena in the mid-Holocene, c. 6000–4000 yrbp. This decline in coastal resources is linked to the drop in sea level throughout the Pacific, which may have caused the widespread population dislocations that ultimately led to the human expansion throughout Oceania. Main conclusions Climate and sea-level changes played a central role in the peopling of the circum-Pacific region. [ABSTRACT FROM AUTHOR]

The coastal zone of the Pacific Rim is home for about one-third of the world's population. Disproportionate growth of Far Eastern economies has produced a disproportionate share of related environmental difficulties. As the region searches for acceptable compromises between growth and environmental quality, its influence on global environmental health is certain to increase. Consequences of global environmental change such as habitat alteration, storms, and sea-level rise will be particularly acute among Pacific Rim nations. Adverse health effects from arsenic exposure in Pacific Rim nations have been used to justify drinking water standards in the United States and elsewhere. As global manufacturing in the Pacific Rim increases, the centroid of global air quality and waste management issues will shift further toward Far Eastern nations. The Eleventh International Conference of the Pacific Basin Consortium (PBC) was held in September 2005 in Honolulu, Hawaii. The purpose of the conference was to bring together individuals to discuss regional challenges to sustainable growth. The historic emphasis of the conference on hazardous wastes in relation to human health makes the PBC an ideal forum for discussing technical aspects of sustainable economic growth in the Pacific region. That role is reflected in the 2005 PBC conference themes, which included management of arsenic in potable waters, air quality, climate change, pesticides, mercury, and electronics industry waste—each with emphasis on relationships to human health. Arsenic management exemplifies the manner in which the PBC can focus interdisciplinary discussion in a single technical area. The conference program provided talks on arsenic toxicology, treatment technologies, management of arsenic-bearing residuals from water treatment, and the probable societal costs and benefits of arsenic management. [ABSTRACT FROM AUTHOR]

This study examines the double–intertropical convergence zone (ITCZ) problem in the coupled general circulation models (CGCMs) participating in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). The twentieth-century climate simulations of 22 IPCC AR4 CGCMs are analyzed, together with the available Atmospheric Model Intercomparison Project (AMIP) runs from 12 of them. To understand the physical mechanisms for the double-ITCZ problem, the main ocean–atmosphere feedbacks, including the zonal sea surface temperature (SST) gradient–trade wind feedback (or Bjerknes feedback), the SST–surface latent heat flux (LHF) feedback, and the SST–surface shortwave flux (SWF) feedback, are studied in detail. The results show that most of the current state-of-the-art CGCMs have some degree of the double-ITCZ problem, which is characterized by excessive precipitation over much of the Tropics (e.g., Northern Hemisphere ITCZ, South Pacific convergence zone, Maritime Continent, and equatorial Indian Ocean), and are often associated with insufficient precipitation over the equatorial Pacific. The excessive precipitation over much of the Tropics usually causes overly strong trade winds, excessive LHF, and insufficient SWF, leading to significant cold SST bias in much of the tropical oceans. Most of the models also simulate insufficient latitudinal asymmetry in precipitation and SST over the eastern Pacific and Atlantic Oceans. The AMIP runs also produce excessive precipitation over much of the Tropics, including the equatorial Pacific, which also leads to overly strong trade winds, excessive LHF, and insufficient SWF. This suggests that the excessive tropical precipitation is an intrinsic error of the atmospheric models, and that the insufficient equatorial Pacific precipitation in the coupled runs of many models comes from ocean–atmosphere feedback. Feedback analysis demonstrates that the insufficient equatorial Pacific precipitation in different models is associated with one or more of the following three biases in ocean–atmosphere feedback over the equatorial Pacific: 1) excessive Bjerknes feedback, which is caused by excessive sensitivity of precipitation to SST and overly strong time-mean surface wind speed; 2) overly positive SST–LHF feedback, which is caused by excessive sensitivity of surface air humidity to SST; and 3) insufficient SST–SWF feedback, which is caused by insufficient sensitivity of cloud amount to precipitation. Off the equator over the eastern Pacific stratus region, most of the models produce insufficient stratus–SST feedback associated with insufficient sensitivity of stratus cloud amount to SST, which may contribute to the insufficient latitudinal asymmetry of SST in their coupled runs. These results suggest that the double-ITCZ problem in CGCMs may be alleviated by reducing the excessive tropical precipitation and the above feedback-relevant errors in the atmospheric models. [ABSTRACT FROM AUTHOR]

The link between the changes in equatorial background stratification and El Niño–Southern Oscillation (ENSO) modulation is investigated using a simulation from a 260-yr-long coupled general circulation model (CGCM). The work focuses on the role of nonlinearities associated with equatorial wave dynamics. As a first step, the low-frequency change in mean stratification is diagnosed and documented from the shallow-water parameters derived from a vertical mode decomposition of the CGCM. The parameters vary differently according to the baroclinic mode order, which may explain why a flattening thermocline does not necessarily lead to reduced ENSO activity. Estimations of baroclinic mode contributions to zonal current anomalies indicate that the decadal variability projects differently for the baroclinic modes as compared to the interannual variability. In particular, the high-order modes associated with decadal variability have a more pronounced signature in the western Pacific, whereas that associated with interannual variability (i.e., ENSO) shows more energy in the eastern Pacific. In the light of the results of the CGCM vertical mode decomposition, an intermediate coupled model (ICM) is used to test whether the nonlinearities associated with the changes in the baroclinic mode energy distribution can lead to coherent ENSO modulation. The results indicate that rectification of the interannual variability (ENSO time scales) by the interdecadal variability associated with changes in the oceanic mean states takes place in the ICM. The rectified effect results mostly in an increased variability and skewness of the zonal advection, which tends to produce a zonal seesaw of the sea surface temperature anomaly. A tropical mechanism for producing ENSO modulation is then proposed that reconciles both the rectified effect resulting from nonlinearities associated with equatorial wave dynamics and the tropical decadal mode of thermocline depth arising from Ekman-pumping anomalies located in the central South Pacific. [ABSTRACT FROM AUTHOR]

The article reports that contrary to common belief, the Pacific region was exempt from the climate changes seen in other areas of the planet during the Medieval Warm Period (AD 900-1200) and the Little Ice Age (AD 1550-1900). During the Medieval Warm Period, coral records show that the tropical Pacific was cool and dry, while during the Little Ice Age, the area was warmer and subject to wet and stormy conditions. The article considers the implications of climate change variability for the prehistoric human populations of the region.

Multicentury integrations from two global coupled ocean–atmosphere–land–ice models [Climate Model versions 2.0 (CM2.0) and 2.1 (CM2.1), developed at the Geophysical Fluid Dynamics Laboratory] are described in terms of their tropical Pacific climate and El Niño–Southern Oscillation (ENSO). The integrations are run without flux adjustments and provide generally realistic simulations of tropical Pacific climate. The observed annual-mean trade winds and precipitation, sea surface temperature, surface heat fluxes, surface currents, Equatorial Undercurrent, and subsurface thermal structure are well captured by the models. Some biases are evident, including a cold SST bias along the equator, a warm bias along the coast of South America, and a westward extension of the trade winds relative to observations. Along the equator, the models exhibit a robust, westward-propagating annual cycle of SST and zonal winds. During boreal spring, excessive rainfall south of the equator is linked to an unrealistic reversal of the simulated meridional winds in the east, and a stronger-than-observed semiannual signal is evident in the zonal winds and Equatorial Undercurrent. Both CM2.0 and CM2.1 have a robust ENSO with multidecadal fluctuations in amplitude, an irregular period between 2 and 5 yr, and a distribution of SST anomalies that is skewed toward warm events as observed. The evolution of subsurface temperature and current anomalies is also quite realistic. However, the simulated SST anomalies are too strong, too weakly damped by surface heat fluxes, and not as clearly phase locked to the end of the calendar year as in observations. The simulated patterns of tropical Pacific SST, wind stress, and precipitation variability are displaced 20°–30° west of the observed patterns, as are the simulated ENSO teleconnections to wintertime 200-hPa heights over Canada and the northeastern Pacific Ocean. Despite this, the impacts of ENSO on summertime and wintertime precipitation outside the tropical Pacific appear to be well simulated. Impacts of the annual-mean biases on the simulated variability are discussed. [ABSTRACT FROM AUTHOR]

A reduced-gravity shallow-water model, an oceanic general circulation model for the Pacific region, and the analytical model of the equatorial β plane bounded in the zonal direction are used to investigate the equatorial thermocline response to tropical and subtropical wind stress forcing. The results show that the wind stress forcing in the tropical and subtropical region can generate a nearly zonal uniform thermocline depth change in the equatorial region. The response timescale is longer when the wind stress is placed farther away from the equator. There exist latitude bands around 10°–15°N and 10°–15°S where the forcing can cause a relatively large equatorial response. When the forcing is located in the eastern basin, the response timescale is longer and its magnitude is larger than the case when the forcing is located in the western basin. Thus the eastern tropical to subtropical region is a relatively effective area for off-equatorial wind stress to generate an equatorial thermocline response. When the wind stress forcing has a longer period, the response of the equatorial thermocline has a larger magnitude. The results from this study's numerical experiments and the analytical solution are consistent. The present study has implications for the broad-scale ocean–atmosphere interaction in the tropical region. [ABSTRACT FROM AUTHOR]

Decadal to interdecadal timescale variability in the Pacific region, commonly referred to as the Pacific decadal oscillation (PDO), is studied in this research using analytical and numerical models. A coupled analytical model is formulated to analyze the physical mechanism of both the PDO and ENSO. It has the equatorial β-plane dynamics of a reduced-gravity model coupled with the wind stress of fixed spatial patterns. The amplitude of the latter is proportional to the sea surface temperature (SST) anomaly in the eastern equatorial Pacific. The SST anomaly is governed by a simple thermal dynamic equation used for ENSO modeling. It is found that when a warm SST is coupled with cyclonic wind stress patterns in the eastern subtropical Pacific, an oscillation with a timescale of around 10–15 yr could be generated. In contrast, when a warm SST is coupled with only a westerly wind stress in the central equatorial Pacific, an ENSO-like oscillation could be generated with a timescale of around 3–5 yr. Thus the present research is potentially relevant to aspects of the PDO and the mechanism of the PDO may be understood as a weakly coupled decadal recharge oscillator similar to the recharge oscillator dynamics of ENSO. The sensitivity of these two kinds of coupled modes to different parameters is tested. Numerical integrations with the reduced-gravity shallow-water model in a rectangular basin and a similar coupled framework confirm the results of the analytical model. [ABSTRACT FROM AUTHOR]

Subsistence systems in insular Southeast Asia and the western Pacific are geographically patterned: from west to cast, grain crops disappear while root and tree crops become more important, and south of the Torres Strait no crops are grown. Previous explanations for these patterns have assumed either a historical cause [the expansion of root and tree crops before grain crops] or some form of environmental filter. Paralleling the agricultural pattern is a west-to-east pattern of increasing variability in inter-annual rainfall variation. I propose that this variability limited the utility of annual crops and increased reliance on long-lived plants whose food production averages across longer periods. The range of human responses to these difficult conditions is illustrated by discussion of the anomalies represented by the unique qualities of the agricultural regimes of Botel Tobago and eastern Melanesia and by the distribution of crops and subsistence systems across the Torres Strait. [ABSTRACT FROM AUTHOR]

Abstract Aim To reconstruct the history of vegetation and environments using pollen, charcoal and sediment analysis, and to identify the timing and nature of climate change and human impact on the vegetation of a remote Pacific island. Location Cerro de Los Inocentes, 1000 m above sea level, Alexander Selkirk Island (33°45′S, 80°45′W), Chile. The westernmost island of the Juan Fernandez Archipelago, south-east Pacific Ocean. Methods A 150-cm long sediment core comprising 87 cm dark brown peat overlying 63 cm of yellow grey clay was extracted from a shallow depression on the southern slopes of Cerro de Los Inocentes. Pollen, charcoal, sediment and accelerator mass spectrometry radiocarbon analyses were used to construct a record of vegetation change through time. Numerical analysis of multispecies data allowed the classification of fossil assemblages into distinct pollen zones. Results Pollen and spores are preserved throughout the sediment with high concentrations coinciding with the beginning of organic sediment accumulation at around 8000 14 C yr BP. Prior to 8000 14 C yr BP, the deposition of clays, presumably from upslope erosion, occurred in a landscape sparsely vegetated by grasses, ferns and Pernettya rigida heath, including several plants that are only found 100–200 m above the site today (Zone CI-1). After 8000 14 C yr BP, a P. rigida heath was the dominant vegetation (Zone CI-2). A shift to a wet heath–shrubland (Zone CI-3) occurred at 6000 14 C yr BP and was followed by a transition to a treefern–shrubland mosaic accompanied by periodic burning (Zone CI-4) after 4500 14 C yr BP. The impact of human occupation is evident in Zone CI-5 at 450 14 C yr BP with the loss of forest species, increased burning and invasion of the exotic plant Rumex . Main conclusions The pollen and charcoal record provides the first evidence of vegetation changes... [ABSTRACT FROM AUTHOR]

ABSTRACT Using an updated Kaplan et al. global SST anomaly (SSTA) dataset (1870-1999) a canonical representation of El Nino-Southern Oscillation (ENSO) is constructed. When this canonical ENSO is subtracted from the data, a residual (non-ENSO) dataset for SSTA is left that includes interseasonal to multidecadal variability. Over the eastern equatorial Pacific (Nino-3) the canonical ENSO accounts for about 79% of the total SSTA variability, and the residual, dominated by decadal timescales, accounts for the rest. In particular, about 40%-50% of the amplitudes of the strong 1982-83 and 1997-98 El Nino events were accounted for by the residual variability. The non-ENSO variability is characterized by the known shift from cold to warm eastern tropical Pacific in the mid- to late 1970s as well as by a (nonstationary) interannual variance increase during the 1980s and 1990s. Composite maps of surface (SST, sea level pressure, and winds) and tropospheric (divergent winds, velocity potential, and vertical velocity) variables are used to compare the spatial patterns characterizing the canonical ENSO and the residual components of the Nino-3 variability. The residual composites are found to only share large-amplitude fluctuations of SST anomalies in the equatorial Pacific east of the date line. When these composites are separated into decadal and interannual components, the decadal part closely... [ABSTRACT FROM AUTHOR]

Variations in the atmospheric boundary layer structure over the eastern equatorial Pacific are analyzed using 916 soundings collected during the First Global Atmospheric Research Program Global Experiment. Unstable boundary layer structures are observed much more frequently in soundings north of the ocean front located near 2.58N in the eastern equatorial Pacific than in soundings south of the front. An objective criterion is applied to identify the presence of the transition layer, a weak stable layer near cloud base, in the soundings. The transition is observed in about 45% of the soundings in both the unstable and the inversion categories. A comparison of soundings over the cold tongue with those over the ITCZ indicates that differences in static stability between these regions are limited to the layer from the surface to about 850 mb, which is the mean height of the inversions capping the cloud layer over the cold tongue. The cold tongue soundings on average are found to be drier from the surface to 300 mb than the ITCZ soundings with the largest average difference (;5 g kg 21 ) between these two groups of soundings observed just above the inversion layer. Compensating subsidence from the ITCZ may account for some of the drying observed just above the cold tongue inversions, although horizontal advection may also be a factor. North--south cross sections (108S--158N) of potential temperature, mixing ratio, equivalent potential temperature, and meridional wind across the cold tongue--ITCZ complex (CTIC) were constructed for two longitudinal bands: 958--1058W and 1058--1158W. There is little latitudinal variation of the average height of the trade inversion and the height of the transition layer across the CTIC. Although the average lifting condensation level (LCL) at 980 mb is located near the average top of the transition layers observed over the cold tongue, the average 980-mb LCL is close to the average height of the base of the transition... [ABSTRACT FROM AUTHOR]

Among the statistical methods used for seasonal climate prediction, canonical correlation analysis (CCA), a more sophisticated version of the linear regression (LR) method, is well established. Recently, neural networks (NN) have been applied to seasonal climate prediction. Unlike CCA and LR, NN is a nonlinear method, which leads to the question whether the nonlinearity of NN brings any extra prediction skill. In this study, an objective comparison between the three methods (CCA, LR, and NN) in predicting the equatorial Pacific sea surface temperatures (in regions Niño112, Niño3, Niño3.4, and Niño4) was made. The skill of NN was found to be comparable to that of LR and CCA. A cross-validated t test showed that the difference between NN and LR and the difference between NN and CCA were not significant at the 5% level. The lack of significant skill difference between the nonlinear NN method and the linear methods suggests that at the seasonal timescale the equatorial Pacific dynamics is basically linear. [ABSTRACT FROM AUTHOR]

Space-borne ozone (O3) measurements have indicated consistent positive trends across the entire Asia–Pacific region despite the considerable reduction of NOx since 2000s. The rate of increase in O3 derived from lower free tropospheric column measurements was observed to be 0.21 ± 0.05 DU/decade during 2005–2018. Our space-borne-based diagnosis of the nonlinear photochemical formation regimes, NOx-limited and NOx-saturated, show that O3 chemistry is undergoing a transitional process to the NOx-limited regime throughout most of the Asian region. Nevertheless, NOx-saturated conditions persist at present in and over eight major megacities. These NOx-saturated conditions in megacities contribute to the increased O3 due to NOx reduction, which could also affect the enhanced O3 concentrations throughout the Asia–Pacific region via long-range transport. This indicates that VOC limits along with NOx reductions are needed in megacities in the short term to reduce O3 levels. Moreover, NOx saturation in major megacities will continue until 2025, according to the forecast emission scenarios from the Intergovernmental Panel on Climate Change (IPCC). These scenarios gradually shift nearly all cities to the NOx-limited regime by 2050 with the exception of few cities under IPCC RCP8.5. Thus, continued reductions in NOx will be a key factor in reducing O3 in the long term. [ABSTRACT FROM AUTHOR]