Search

Simple Summary: During overwintering diapause, the gynes of paper wasps (Polistes sp.) are mainly dormant in sheltered hibernacles, protecting them against predators and adverse weather conditions but hardly against low temperatures. By measuring the temperature inside hibernacles occupied by species from both Mediterranean (Italian; P. dominula, P. gallicus) and temperate (Austrian; P. dominula) climates (mean hibernacle temperatures: 8.5 °C and 3.2 °C, respectively), we were able to calculate the energetic demand of overwintering. The cumulative energetic costs differed between the populations. Costs were lowest for the P. dominula population from the cooler Austrian winter climate and significantly higher in P. dominula and P. gallicus from the warmer Italian climate. The lower costs of the temperate species were a result of the lower winter temperature and physiological acclimation processes. Energetic calculations with an assumed temperature increase of up to 3 °C due to climate change predict a dramatic increase of up to 40% in overwintering costs in all species. Gynes of paper wasps (Polistes sp.) spend the cold season in sheltered hibernacles. These hibernacles protect against predators and adverse weather conditions but offer only limited protection against low temperatures. During overwintering diapause, wasps live on the energy they store. We investigated the hibernacles' microclimate conditions of species from the Mediterranean (Italy, P. dominula, P. gallicus) and temperate (Austria, P. dominula) climates in order to describe the environmental conditions and calculate the energetic demand of overwintering according to standard metabolic rate functions. The temperatures at the hibernacles differed significantly between the Mediterranean and temperate habitats (average in Austria: 3.2 ± 5.71 °C, in Italy: 8.5 ± 5.29 °C). In both habitats, the hibernacle temperatures showed variance, but the mean hibernacle temperature corresponded closely to the meteorological climate data. Cumulative mass-specific energetic costs over the studied period were the lowest for the temperate P. dominula population compared with both Mediterranean species. The lower costs of the temperate species were a result of the lower hibernacle temperature and acclimation to lower environmental temperatures. Model calculations with an increased mean temperature of up to 3 °C due to climate change indicate a dramatic increase of up to 40% in additional costs. [ABSTRACT FROM AUTHOR]

AI chatbots such as ChatGPT help people produce texts. According to media reporting, these texts are also used for educational purposes. Thus, AI influences people's knowledge and perception of current issues. This paper examines the narrative of ChatGPT's stories on climate change. Our explorative analysis reveals that ChatGPT's stories on climate change show a relatively uniform structure and similar content. Generally, the narrative is in line with scientific knowledge on climate change; the stories convey no significant misinformation. However, specific topics in current debates on global warming are conspicuously missing. According to the ChatGPT narrative, humans as a species are responsible for climate change and specific economic activities or actors associated with carbon emissions play no role. Analogously, the social structuration of vulnerability to climate impacts and issues of climate justice are hardly addressed. ChatGPT's narrative consists of de-politicized stories that are highly optimistic about technological progress., (© 2024. The Author(s).)

Global land surface air temperature data show that in the past 50 years, the rate of nighttime warming has been much faster than that of daytime, with the minimum daily temperature (Tmin) increasing about 40% faster than the maximum daily temperature (Tmax), resulting in a decreased diurnal temperature difference. The Qinghai-Tibet Plateau (QTP) is known as the "roof of the world", where temperatures have risen twice as fast as the global average warming rate in the last few decades. The factors affecting vegetation growth on the QTP are complex and still not fully understood to some extent. Previous studies paid less attention to the explanations of the complicated interactions and pathways between elements that influence vegetation growth, such as climate (especially asymmetric warming) and topography. In this study, we characterized the spatial and temporal trends of vegetation coverage and investigated the response of vegetation dynamics to asymmetric warming and topography in the QTP during 2001-2020 using trend analysis, partial correlation analysis, and partial least squares structural equation model (PLS-SEM) analysis. We found that from 2001 to 2020, the entire QTP demonstrated a greening trend in the growing season (April to October) at a rate of 0.0006/a (p < 0.05). The spatial distribution pattern of partial correlation between NDVI and Tmax differed from that of NDVI and Tmin. PLS-SEM results indicated that asymmetric warming (both Tmax and Tmin) had a consistent effect on vegetation development by directly promoting greening in the QTP, with NDVI values being more sensitive to Tmin, while topographic factors, especially elevation, mainly played an indirect role in influencing vegetation growth by affecting climate change. This study offers new insights into how vegetation responds to asymmetric warming and references for local ecological preservation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Global warming has brought extensive and far-reaching impacts on human life and production. A pumped hydro energy storage contributes to the large-scale development of renewable energy and serves as an important measure to mitigate climate change. Despite considerable efforts in estimating the potential of the pumped hydro energy storage, research gaps in response to global warming remain. In this regard, this study conducts a novel assessment of the pumped hydro energy storage's potential from a dynamic perspective, taking the Qinghai-Tibet Plateau as the study area. The spatiotemporal evolution of the pumped hydro energy storage's potential over the past few decades (the 1970s-2017) is analyzed, and its response to precipitation is identified innovatively. On this basis, the trend in the future period is further predicted for the first time, which is divided into near, short, medium, and long terms. Results show that the pumped hydro energy storage potential has a generally upward but not monotonic trend, decreasing from the 1970s to 1995 and then rising more dramatically, with slopes of 5548.5 ± 69.2 GWhyr -1 and -238.1 ± 90.4 GWhyr -1 . In the majority (68.6 %) of lake basins (68.6 %), changes in precipitation positively contribute to the pumped hydro energy storage potential, resulting in a noticeable growth in the future. Under the representative concentration pathway of 8.5, the mean potential density is projected to rise by 23.4 %, 25.2 %, 28.3 %, and 30.6 % in the near, short, medium, and long terms, respectively. This result indicates that high-intensity greenhouse gas emissions under this scenario will lead to a greater potential for the pumped hydro energy storage in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Most studies on the impact of climate change on foods focus on the consequences to security and safety. In the present study we provide scientific evidence on an overlooked aspect of climate change related to the microbiological stability of foods. Most microbiologically stable processed foods are contaminated with spores of thermophilic spoilage bacteria which are highly heat-resistant and can survive thermal processing. Current temperatures during distribution and storage in temperate climates do not allow growth of thermophilic bacteria to levels that can cause spoilage, ensuring their microbiological stability. Our findings suggest that the latter limiting condition can be eliminated by global warming. By assessing different global warming scenarios for 38 European cities in a case study with canned milk, we show that failing to limit the increase of global mean surface temperature below 2 °C can lead to a very high risk of spoilage and subsequently cause a collapse of the shelf-stable food chain., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Changes in extreme events have received increasing attention in the context of climate change. Extreme changes in wet and dry events due to changes in meteorological elements, such as the spatial and temporal redistribution of precipitation and temperature increases, are extreme weather events that have attracted much attention in recent years. In contrast, there is a relative lack of research on extreme compound events that focuses on a transition between wet and dry spells in adjacent months. This paper provides maps of the frequency, duration, and severity of national-scale dry wet abrupt alternation (DWAA) events for 1980-1999 and 2000-2019, aiming to obtain information regarding events in the hotspot areas of DWAA in China during the past four decades in order to analyze their change patterns. This paper performs station-based standardized precipitation evapotranspiration index (SPEI) calculations to characterize local wet and dry spells based on meteorological observations provided by the China Meteorological Administration (CMA) since 1980 with regional analyses based on seven geographic divisions of China. Our finding explicitly discloses the "more-less-more" DWAA variation pattern from North to South China. Additionally, the changes in frequency, duration, and severity in the different regions are revealed. The frequency, duration, and severity of DW increased from 5.08 to 6.74, 17.71 to 24.62, and 12.51 to 17.01, respectively, an increase of 32.53%, 39.04% and 36.01%, while the corresponding WD only increased by 9.45%, 15.22% and 13.51%. In addition, events with a higher severity of DWAA are prone to appear in most regions due to the increasing interval between heavy rainfall and the increase in precipitation under global warming., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest to this work., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The South African government's response to the universal crisis of global warming has resulted in the creation of the National Climate Change Response White Paper, a proposed country-wide course of action that would aid in the stabilization of greenhouse gas emissions and intervene in current harmful environmental practices. The role of communication and the media is crucial to the success of any policy implementation as well as of the establishment of an 'action-inspired' mind-set amongst citizens that will bolster lifestyle change to support the cause. This paper will assess the National Climate Change Response White Paper in conjunction with climate change coverage from the South African daily online news source, News 24. Additionally, films released from the Bjerkness Centre for Climate Research and discussion surrounding youth's use of relatable mediums to invoke lifestyle change from Lindie Buirski, Head of Environmental Capacity Building, Training and Education in the City of Cape Town's Environmental Resource Management (ERM) Department, will aid in analysis. Moreover, they will serve to bolster the argument of communications' critical role in realizing any goals set forth by the government. The paper will close by offering proposed climate-change directed development projects for the South African context and will refer to current international successful examples of media use to carry the message of climate change, while inviting audience input, participation, and most importantly, action. [ABSTRACT FROM AUTHOR]

Urbanization is one of the pivotal aspects of socioeconomic advancement which is critically vulnerable to climatic extremes. Extreme precipitation and urbanization are largely interlinked. Estimating the extreme precipitation-induced urban area exposure is the fundamental aspect of urban risk assessment for precipitation-related floods. In this study, future urban area exposure to extreme precipitation and associated influential factors are investigated over South Asia under 1.5 °C, 2.0 °C, 3.0 °C, and 4.0 °C global warming thresholds. In this regard, we used newly released 20 up-to-date climate models outputs, and five Integrated Assessment Models (IAMs) based urban land-use products under four combined scenarios of the Shared Socioeconomic Pathways and Representative Concentration Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) from the sixth phase of Coupled Model Intercomparison Project (CMIP6). Extreme precipitation is characterized by adopting 20-, 50-, and 100-year return periods of annual maximum daily precipitation. Results reveal a massive urban area expansion over South Asia which is the utmost by 186.4% under SSP3-7.0 than the reference period (1995-2014). The variations in projected urban areas mainly occur in Indo-Gangetic Plain (IGP) region among scenarios. In relative terms, extreme precipitation frequency and associated urban area exposure are prospective to increase with continued global warming. The exposed urban area varies 4.5- to 7.4-fold higher under different warming thresholds than the reference period. The leading increase is estimated (7.4-fold) under 4.0 °C. Notably, for global warming targets set out by the Paris Agreement (1.5 °C, and 2.0 °C), exposed urban area is intended to be 10.2% higher under 2.0 °C than 1.5 °C. Spatially, the exposed urban area will be dominant in the southeast region relative to the reference period. Importantly, the interaction effect (simultaneous change in climate-urban land) is the principal contributor to the changes in urban area exposure to extreme precipitation over South Asia. However, this study's findings strongly support the accomplishment of the Paris Agreement target and provide a scientific basis for formulating urban land-use policy interventions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

The warming magnitudes under different shared socioeconomic pathways (SSPs) and the spatial distribution of global land surface air apparent temperature (APT) since the early of the 20 century were systematically analyzed, based on the comparisons among in-situ observations, extended reanalysis, and the CMIP6 model output. The warming of APT by the mid and late 21st century was then projected, as well as under the 1.5 °C and 2.0 °C threshold for global warming. The study reveals: 1) the CMIP6 multi-model ensemble mean (MME) agrees well with the observations in terms of the climatological mean and temporal variations for the global land surface air temperature (SAT) and the calculated APT over the past 100 years. 2) Although the spatial gradient distribution of SAT and APT is quite similar under SSP2-4.5 and SSP5-8.5, the warming trend of global surface APT over land is significantly larger than that of SAT. Population living in low latitudes will be more vulnerable to the enhanced warming of APT. 3) Under the global warming thresholds of 1.5 °C and 2.0 °C, the global mean APT estimated under SSP2-4.5 and SSP5-8.5 is identical, which are 1.9 °C and 2.7 °C, respectively. The projected APT will increase by 3.9 °C under SSP2-4.5 and 6.7 °C under SSP5-8.5 at the end of the 21st century relative to the pre-industrial. This study highlights that the probability and intensity of extreme warm events for land SAT and APT around the globe under SSP5-8.5 will be remarkably higher than SSP2-4.5 in the 21st century, implying the urgent demand of regulating greenhouse gas emissions toward reducing thermal discomfort in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Vegetation is highly sensitive to climate changes in arid regions. The relationship between vegetation and climate changes can be effectively characterized by vegetation phenology. However, few studies have examined the vegetation phenology and productivity changes in arid Central Asia (ACA). The vegetation phenological information of ACA was extracted using MODIS NDVI (Normalized Difference Vegetation Index) data, and the dynamics of vegetation phenological changes under spatiotemporal variations were quantitatively assessed. Moreover, the impacts of climate change on vegetation phenology and net primary productivity were analyzed by combining meteorological data with that of MODIS NPP (Net Primary Productivity) during the same period. The results demonstrated that the start of the season (SOS) of vegetation in the study was concentrated from mid-February to mid-April, while the end of the season (EOS) was concentrated from early October to mid-December. The length of growing season (LOS) ranged from 6 to 10 months. The SOS of vegetation was gradually postponed at a rate of 0.16 d·year -1 . The EOS advanced at a rate of 0.69 d·year -1 . The LOS was gradually shortened at a rate of 0.89 d·year -1 . For each per 1000 m increase in elevation, the SOS of vegetation was postponed by 12.40 d; the EOS advanced by 0.40 d, and the LOS was shortened by 11.70 d. For the impacts of climate changes on vegetation phenology and NPP, the SOS of vegetation phenology negatively correlated with temperature but positively correlated with precipitation and NPP. The EOS and LOS positively correlated with temperature but negatively with precipitation and NPP. Results indicated that the SOS was not moved ahead but was delayed, while the EOS advanced rather than being postponed under climate change. These results can offer new insights on the phenological response to climate change in arid regions and on non-systematic changes in phenology under global warming., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This paper tries to introduce a time-series of temperature parameters as a potential method for studying the global warming. So, we investigated the spatial-temporal variations of warm-season temperature parameters (WSTP), including start time, end time, length of season, base value, peak time, peak value, amplitude, large integrated value, right drive, and left drive, using a database of 30 years' period in different climates of Iran. We used daily temperature data from 1989 to 2018 over Iran to extract the parameters by TIMESAT software. We studied the trend analysis of WSTP through the Mann-Kendall method. Then, we considered the Pearson correlation coefficient to calculate the correlation between WSTP and time. We assessed the trends of the slope using a simple linear regression method. Then, we compared the results of the WSTP trend analysis in climatic zones. Our results accused the hyper-arid climatic zone has the longest warm season (194.89 days a year). The warm season in this region starts earlier than other regions and increases with moderate speed (left drive, 0.19 °C day -1 ). Then, it reaches a peak value (31.3 °C) earlier than the different climatic zones. On the other hand, the humid regions' warm season starts with the shortest length and ends later than the other climatic zones (112.1 and 297.5 days a year for start and end times, respectively). We detected that the trend of the start time parameter has decreased by 98.02% of the study area during the last 30 years. The base value, length, and large integrated value parameters have an increasing trend of 66.47%, 80.11%, and 92.95% in Iran. The highest correlation coefficient with time was for start time and large integrated value parameters. Hence, the start time and large integrated value parameters have almost the most negative (< - 0.5) and positive (> 5) trend slope, among other parameters, respectively. In general, these results demonstrate that the studied region has faced global warming impacts over time by increasing the warm season and thermal energy, especially in arid and hyper-arid. We highlight the necessity of planning the land use under the high natural vulnerability of the studied local, especially in this new age of global warming., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A large majority of climate change studies carried out to date are on changes in mean climate, which have comparatively downplayed variability. In terms of trend analysis or forecast, the scientific output and common knowledge for global warming are much more robust than for changes in temperature variability. Quantification of temperature variability adds another dimension of temporal scale, requiring immense labor and presenting great uncertainty. Regardless, this endeavor is necessary since changes in ambient temperature variabilities could also contribute to current and future human health burden besides changes in mean quantities. Here, we review the current literature on trends of surface air temperature variability defined at a range of timescales, aiming to tease out the welter of evidence and thus improving the scientific recognition of changes in air temperature variability in the context of climate change. The findings of reviewed studies from numerous regions differ substantially over various temporal scales. In general, the ambient temperature variability on short time scales (e.g., diurnal or inter-day) shows a downward trend, while it is increasing on longer time scales (e.g., inter-annual). We then move beyond the review and deliver an extended discussion of potential implications for future research related to ambient temperature variability. We highlight the need to consider the methodological choices, especially timescales of interest, in the trend analysis as well as health impact studies. Continued research focusing on temperature variability at multiple timescales, with concerted efforts from scientists of all relevant stripes, is meaningful in synthesizing knowledge and reducing uncertainties surrounding air temperature variability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Growing concerns for the rapidly expanding material consumption and rising greenhouse gas emissions have necessitated the United Nation's inclusion of Goal 12 (sustainable consumption) and Goal 13 (climate change) into sustainable development goals. These inclusions call for more ambitious plans, accelerated actions, and policies that will improve resource efficiency, reduce waste, and mainstream sustainability practices across multiple sectors of the economy. While the focus has been on several sectors (such as manufacturing, mining, agriculture, etc.), the education sector has received less attention in terms of its contribution to climate change. Hence, this study seeks to connect the dots between academic activities and climate change. Using the Vaal University of Technology in South Africa as a case study, the research addresses environmental issues by investigating students' attitudes toward paper consumption and reuse or recycling. The findings from the study show a high paper consumption and low recovery rate on campus. Hence, the study employed the incentive theory of motivation to develop a strategic response called the Sustainable Printing Workflow (SPW), which could help increase the paper recovery rate and mainstream sustainability practices in the education sector by reducing waste and enhancing efficient paper consumption and recycling. [ABSTRACT FROM AUTHOR]

Background: Investigating future changes in temperature-related mortality as a function of global mean temperature (GMT) rise allows for the evaluation of policy-relevant climate change targets. So far, only few studies have taken this approach, and, in particular, no such assessments exist for Germany, the most populated country of Europe., Methods: We assess temperature-related mortality in 12 major German cities based on daily time-series of all-cause mortality and daily mean temperatures in the period 1993-2015, using distributed-lag non-linear models in a two-stage design. Resulting risk functions are applied to estimate excess mortality in terms of GMT rise relative to pre-industrial levels, assuming no change in demographics or population vulnerability., Results: In the observational period, cold contributes stronger to temperature-related mortality than heat, with overall attributable fractions of 5.49% (95%CI: 3.82-7.19) and 0.81% (95%CI: 0.72-0.89), respectively. Future projections indicate that this pattern could be reversed under progressing global warming, with heat-related mortality starting to exceed cold-related mortality at 3 °C or higher GMT rise. Across cities, projected net increases in total temperature-related mortality were 0.45% (95%CI: -0.02-1.06) at 3 °C, 1.53% (95%CI: 0.96-2.06) at 4 °C, and 2.88% (95%CI: 1.60-4.10) at 5 °C, compared to today's warming level of 1 °C. By contrast, no significant difference was found between projected total temperature-related mortality at 2 °C versus 1 °C of GMT rise., Conclusions: Our results can inform current adaptation policies aimed at buffering the health risks from increased heat exposure under climate change. They also allow for the evaluation of global mitigation efforts in terms of local health benefits in some of Germany's most populated cities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Urolithiasis is a disease of the genitourinary system, which is defined as the presence of urinary stones at any place in the urinary tract, resulting from the precipitation reaction of chemical compounds. The aim of this study is to demonstrate the important role of selected environmental factors (climate, ambient temperature) and the type of profession performed in the development of urolithiasis. In this field, the literature including original and review papers related to the epidemiology, pathogenesis and risk factors of urolithiasis was analyzed. The study used electronic databases such as Medline, Web of Science and Google Scholar. The prevalence of urolithiasis has increased in recent decades in both developed and developing countries. It is believed that this growing trend is associated with lifestyle changes such as the lack of physical activity, poor eating habits and global warming. Many factors are responsible for the formation of urinary stones. In literature, there is a division into individual and environmental factors. Today, external factors in the form of climate changes (global warming), geographical conditions and seasonal fluctuations, and the type of profession performed are becoming more and more important in the context of the occurrence of urinary stones. Currently, the presence of urolithiasis is becoming a significant problem all over the world and searching for causes is not easy, but particular attention should be paid to certain predispositions resulting from environmental factors, such as ambient temperature and the type of work performed. Int J Occup Med Environ Health. 2019;32(6):761-75. [ABSTRACT FROM AUTHOR]

To investigate the relative contributions of current vs. historical factors in explaining broad-scale diversity gradients using a combination of contemporary factors and a quantitative estimate of the temporal accessibility of areas for recolonization created by glacial retreat following the most recent Ice Age. The part of the Nearctic region of North America that was covered by ice sheets during the glacial maximum 20 000 BP. We used range maps to estimate the species richness of mammals and terrestrial birds in 48 400 km2 cells. Current conditions in each cell were quantified using seven climatic and topographical variables. Historical conditions were estimated using the number of years before present when an area became exposed as the ice sheets retreated during the post-Pleistocene climate warming. We attempted to tease apart contemporary and historical effects using multiple regression, partial regression and spatial autocorrelation analysis. A measure of current energy inputs, potential evapotranspiration, explained 76–82% of the variance in species richness, but time since deglaciation explained an additional 8–13% of the variance, primarily due to effects operating at large spatial scales. Because of spatial covariation between the historical climates influencing the melting of the ice sheet and current climates, it was not possible to partition their effects fully, but of the independent effects that could be identified, current climate explained two to seven times more variance in richness patterns than age. Factors acting in the present appear to have the strongest influence on the diversity gradient, but an historical signal persisting at least 13 000 years is still detectable. This has implications for modelling changes in diversity patterns in response to future global warming. [ABSTRACT FROM AUTHOR]

Motivated by the need to predict how the Arctic atmosphere will change in a warming world, this article summarizes recent advances made by the research consortium NETCARE (Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments) that contribute to our fundamental understanding of Arctic aerosol particles as they relate to climate forcing. The overall goal of NETCARE research has been to use an interdisciplinary approach encompassing extensive field observations and a range of chemical transport, earth system, and biogeochemical models. Several major findings and advances have emerged from NETCARE since its formation in 2013. (1) Unexpectedly high summertime dimethyl sulfide (DMS) levels were identified in ocean water (up to 75 nM) and the overlying atmosphere (up to 1 ppbv) in the Canadian Arctic Archipelago (CAA). Furthermore, melt ponds, which are widely prevalent, were identified as an important DMS source (with DMS concentrations of up to 6 nM and a potential contribution to atmospheric DMS of 20 % in the study area). (2) Evidence of widespread particle nucleation and growth in the marine boundary layer was found in the CAA in the summertime, with these events observed on 41 % of days in a 2016 cruise. As well, at Alert, Nunavut, particles that are newly formed and grown under conditions of minimal anthropogenic influence during the months of July and August are estimated to contribute 20 % to 80 % of the 30–50 nm particle number density. DMS-oxidation-driven nucleation is facilitated by the presence of atmospheric ammonia arising from seabird-colony emissions, and potentially also from coastal regions, tundra, and biomass burning. Via accumulation of secondary organic aerosol (SOA), a significant fraction of the new particles grow to sizes that are active in cloud droplet formation. Although the gaseous precursors to Arctic marine SOA remain poorly defined, the measured levels of common continental SOA precursors (isoprene and monoterpenes) were low, whereas elevated mixing ratios of oxygenated volatile organic compounds (OVOCs) were inferred to arise via processes involving the sea surface microlayer. (3) The variability in the vertical distribution of black carbon (BC) under both springtime Arctic haze and more pristine summertime aerosol conditions was observed. Measured particle size distributions and mixing states were used to constrain, for the first time, calculations of aerosol–climate interactions under Arctic conditions. Aircraft- and ground-based measurements were used to better establish the BC source regions that supply the Arctic via long-range transport mechanisms, with evidence for a dominant springtime contribution from eastern and southern Asia to the middle troposphere, and a major contribution from northern Asia to the surface. (4) Measurements of ice nucleating particles (INPs) in the Arctic indicate that a major source of these particles is mineral dust, likely derived from local sources in the summer and long-range transport in the spring. In addition, INPs are abundant in the sea surface microlayer in the Arctic, and possibly play a role in ice nucleation in the atmosphere when mineral dust concentrations are low. (5) Amongst multiple aerosol components, BC was observed to have the smallest effective deposition velocities to high Arctic snow (0.03 cm s -1). [ABSTRACT FROM AUTHOR]