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Copyright of Revista de Climatología is the property of Revista de Climatologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper explores spatial and temporal variability of rainfall and temperature in Bilate catchment based on monthly data of 11 meteorological stations. Precipitation Concentration Index (PCI) and Pearson product moment correlation were used to estimate monthly concentrations and associations between annual and seasonal rainfall. Similar methods were used to analyze the association of ENSO with rainfall variability using Eastern Equatorial Pacific (Niño 3.4) data, Sea Surface Temperature (SST), and Southern Oscillation Index (SOI). Rainfall and temperature series were tested for trends using the Mann–Kendall test. Rainfall in the catchment is highly seasonal and concentrated in Kiremt (June–September), followed by Belg (February–May). Belg rainfall was highly variable. Annual rainfall was relatively stable in the upper catchment and variable in the lower catchment. PCI values are expected to increase as annual and seasonal rainfall decrease. The middle catchment had significant negative trends in annual and Belg rainfall. November–March SST is strongly associated with Belg rainfall variations throughout the catchment, and ~49% of the variability can be explained by Equatorial Pacific SST. Annual and seasonal temperature significantly increased in middle and lower parts of the catchment in the past 30 years. Warming was ~0.05°C/yr to 0.17°C/yr. [ABSTRACT FROM AUTHOR]

Golden tide outbreak threatened the marine ecological environment. Sargassum horneri is a single dominant species of the Yellow Sea golden tide, which growth and development are affected by changes in sea water temperature. This study investigated the photosynthetic physiology of copper algae and found that the growth rate, chlorophyll a content, carotenoid content, Fv/Fm, and maximum electron transfer efficiency were significantly reduced, indicating that Sargassum horneri was under stress under high temperature. In this study, high-throughput sequencing was used to analyze the response mechanisms of photosynthesis-related genes in S. horneri under high temperature stress. The results showed that most of the photosynthesis-related genes in S. horneri were downregulated and photosynthesis was inhibited under high temperature stress. However, the expression levels of ferredoxin, ferredoxin-NADP reductase, light-harvesting protein complexes, and oxygen-evolving complex genes were significantly upregulated (P ≤ 0.05) after five days of high temperature treatment. This study found that photosynthesis related genes play a crucial role in regulating the photosynthetic response of S. horneri to high temperature stress. • Under high temperature of 25 ℃, the light and parameters of Sargassum horneri decrease, indicating that they are under stress. • In this paper, ACT gene of Sargassum horneri was used as internal reference gene. • Under high temperature stress, the overall expression of genes related to the photosynthetic system of Sargassum horneri was limited. • The expression of OEC,LHC,B6/F genes in photosystem II of Sargassum horneri was down-regulated under short-term high temperature stress. • The upregulating number of PsaD,PsaE and LHC genes increased after 5 days of high temperature stress. [ABSTRACT FROM AUTHOR]

This paper presents the graphical results of the Lagrangian-model and the weathering processes associated with oil spills in the tropical South Atlantic, taking into account the meteorological and oceanographic conditions of the study region. The scenarios were created in the Brazilian-NE waters adjacent, with simulation times of 670 h, and densities of 35, 25, and 15API with volume of 1590 m3 were considered. The main results showed that the meteo-oceanographic characteristics of the study region influence the trajectories and weathering processes in the oil spill. The trajectories varied for each launch point and reached the continent severely in January and October. The associated weathering processes showed higher rates in September and lower rates in April, indicative of the influence of phenomena such as Intertropical Tropical Convergence Zone and warm pool in the South Atlantic region. Sea surface temperature and wind speed are key factors that correlate positively with these months. [Display omitted] • Evaporation, dispersion and water content in the oil show different temporal patterns in April and September. • Wind intensity, wave energy and SST affect weathering processes. • The trajectories change according to the zonal component towards the continent. [ABSTRACT FROM AUTHOR]

The Arabian Gulf is a warm (summer SST > 30 °C) and hypersaline (salinity > 40 psu at any time) marginal sea of the Indian Ocean. This paper reports on a 3-year study of seasonal and spatial changes of primary production and associated physico-chemical and biological parameters in the coastal waters of Saudi Arabia in the western Arabian Gulf. The primary production rates were low and yet showed a seasonality, with a major spring peak and a minor autumn peak, and a possible significant role for heterotrophs. While the strong relationships between the net changes of carbon uptake and nutrients between seasons showed a control of primary production by the availability of nutrients, the decrease in primary production between spring and summer when nutrients continued to increase suggests that the primary production at this time could have been controlled by higher ambient temperatures and intensities of incident light. • This Ms presents data, for the first time, on nutrients and primary production in a large sea area of the Arabian Gulf. • The waters are oligotrophic, with low rates of primary production. • Nutrients play a major role in controlling primary production. • Sea surface temperature and incident light may negatively influence primary production between spring and summer. • Increased anthropogenic inputs may render eutrophic specific locations of this pristine sea area. [ABSTRACT FROM AUTHOR]

In this paper, temporal variability and trends of sea ice in the Kara Sea and their correlations with local atmospheric forcing have been quantified and analyzed based on NSDIC SIC dataset and ECMWF ERA-Interim dataset from 1979 to 2017. The sea ice starts to melt in early May and becomes fully frozen at the end of December. The ice melting process is much slower than freezing process. Since 2005, the lowest coverage has been nearly to be 5%, meaning the extensive ice-free condition in summer. The EOF1 patterns of SIC anomaly coincide well with the spatial patterns of trends of SIC. In winter, the whole domain almost remains unchanged and the declining trends are less than −5%/decade but with two high-value regions between −5 and −15%/decade in northwest and southwest. In summer, the sea ice area, extent and relative concentration have been declining significantly with SIC exceeding −15%/decade in the northern part. The decreasing SIC condition is closely sensitive to air temperature over sea surface with correlation coefficients between 0.5 and 1 in the whole domain. Winter accumulative temperature can significantly determine the ice regime in the following melt-freeze period. Correlation coefficients between winter accumulative temperature and melt-freeze sea ice anomaly index, duration of melt-freeze period can up to be −0.85 and 0.77, respectively. Since 2005, the summer sea ice anomaly index becomes closely related to meridional wind with correlation coefficient approaching 0.72. This sea ice motion becomes more sensitive and easily driven by the meridional strong winds when in lower SIC conditions due to the less internal ice stresses. [ABSTRACT FROM AUTHOR]

To describe the onset and evolution of upwelling along the south west coast of India, authors collected a series of conductivity temperature depth measurements on board INS Sagardhwani extending from 7 °N - 15 °N during the period extending from February 2017 to October 2017. In this paper we utilised the undulations of 23 °C isotherm as a proxy to study the upwelling phenomenon. The upward movement of the waters at the southern tip off India (77.5 °E) in the subsurface levels was observed to commence from late February 2017 in depths around 80 m and by the end of May 2017, it is observed to rise rapidly to the surface. The upwelled waters reach the surface during the 2nd week of July all along the Indian coast, and then intensified during August 2017. Beyond 12 °N maximum upwelling is seen in July and thereafter in early August 2017 upwelling was intense till October 2017. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Outdoor thermal comfort significantly influences the users' experience in urban places; affecting their extent of usage. The paper aims to identify the outdoor thermal benchmarks for the temperate oceanic (Cfb) climate zones in Australia. It examines the perception of thermal comfort in two urban places in Melbourne city. Field measurements were conducted during summer and winter seasons along with 2123 valid questionnaires and observations in both contexts. Micrometeorological parameters were measured and used to calculate the mean radiant temperature and the physiological equivalent temperature (PET). The questionnaire provided information regarding the thermal sensations and preferences of the users using ASHRAE seven-point and McIntyre scales respectively. The quantitative analysis is used to calculate the range of outdoor thermal comfort in Melbourne. This was ranged between 20 °C and 25 °C PET. Additionally, the neutral and preferred temperature were found to be 20.4 °C and 19.2 °C respectively. Variations in different benchmarks were observed with different seasons and types of urban places. The results endorse the significant impact of thermal adaptation factors on the users' comfort levels and acceptability for micrometeorological environments. The findings also identify the different thermal benchmarks that help urban designers creating comfortable outdoor places within the oceanic temperate climatic zones. [ABSTRACT FROM AUTHOR]

The paper addresses the possibilities of spatio-temporal statistical modelling of basic hydrophysical and meteorological parameters of sea surface layer in the south-eastern Baltic Sea, Curonian Lagoon. The aim of the paper is to compare two methods (multivariate linear regression and regression kriging) for the analysis of changes and trends of ice phenomena, their dependence on changes in the air temperature, sea surface temperature and water salinity. The prediction of ice conditions for several locations at different distances from the reference sites shows that spatial information is an extremely important factor in making forecasts. The application of the regression kriging is more efficient than the multivariate linear regression for predicting the ice phenomena in semi-enclosed basins and lagoons. [ABSTRACT FROM AUTHOR]

This paper analyzes CO 2 flux between the atmosphere and a tropical coastal sea using the eddy covariance technique. Coastal carbon dioxide flux studies are limited, particularly in tropical regions. Data was collected from the study site in Pulau Pinang, Malaysia, since 2015. The research found that the site is a moderate CO 2 sink and experiences seasonal monsoonal changes that affect its carbon-sink or carbon-source capability. The analysis showed that the coastal sea systematically shifted from being a carbon-sink at night to a weak carbon-source during the day possibly due to cause by the synergistic influence of wind speed and seawater temperature. The CO 2 flux are also influenced by small-scale, unpredictable winds, limited fetch, developing waves, and high-buoyancy conditions caused by low wind speeds and an unstable surface layer. Furthermore, it exhibited a linear relationship with wind speed. In stable conditions, the flux was influenced by wind speed and drag coefficient, while in unstable conditions, it was mostly controlled by friction velocity and atmospheric stability. These findings could improve our understanding of the critical factors that drive CO 2 flux at the tropical coast. • In-depth analysis of CO2 flux between atmosphere & tropical coastal sea surface using eddy covariance technique. • The tropical coast moves from being a carbon-sink at night to a weak carbon-source at day. • In stable conditions, the flux was influenced by wind speed and drag coefficient. • In unstable conditions, it was mostly controlled by friction velocity and atmospheric stability. [ABSTRACT FROM AUTHOR]

Aquaculture plays a significant role in food security and provides livelihoods and employment for millions of people among coastal communities worldwide. However, the growing aquaculture sector has also created debates around its long-term ecological sustainability, economic viability, potential social inequalities and governance issues. We investigated the perceived challenges and opportunities to achieving sustainable mud crab aquaculture in tropical coastal regions by using the case study of coastal mud crab farms in Andhra Pradesh, India. Informed by perceptions and indicative financial data from a sample of stakeholders we investigated the potential economic outcomes under different scenarios representing varying yield levels, risk factors and project time periods. The main risks identified by the stakeholders were associated with the limited supply of mud crab seeds and the lack of access to governmental and non-governmental support schemes. There are no financial buffers, therefore major disease outbreaks or extreme weather conditions caused by climate change would lead to a loss of livelihoods. This paper also highlights the most critical factor determining the level of success of mud crab farming being the crab survival rate which is influenced by a variety of factors including increasing sea surface temperature. The results of this study show that small-scale mud crab farming has fewer risks and higher flexibility involved than large-scale mud crab farming. It could be an economically sustainable enterprise and serve as a tool for poverty alleviation in developing countries if microfinance support and training are available. • Small-scale mud crab aquaculture can be economically, environmentally and socially sustainable in tropical coastal regions. • The sustainability of mud crab aquaculture expansion depends on access to affordable loans, training and sustainable feed. • Ensuring a high survival rate of mud crabs, influenced by climate change and disease , is critical for aquaculture success. [ABSTRACT FROM AUTHOR]

The rapid industrial and economic development in India leads to high level of pollution in environment. Due to increased level of aerosols oceans are warming. This paper highlights on aerosols effect on sea surface wind and sea surface temperature by using remote sensing data. The windplays important role in Aerosol Optical Depth (AOD) and radiative forcing and is analyzed using National Centers for Environmental Prediction (NCEP) monthly wind data. The radiative forcing observed is much higher and up to 60% of total AOD during summer monsoon. SeaSurface Temperature (SST) is another important parameter in ocean atmosphere system and a key variable in coupling the atmosphere and ocean. The SST has changed during the change of atmospheric pattern and it plays an important role in aerosols mechanism. The study observed that during summer monsoon SST over the South Eastern Tropical Indian Ocean (SETIO) much higher than Western Tropical Indian Ocean (WTIO) and it plays important role in aerosols mechanism. [ABSTRACT FROM AUTHOR]

Extreme environmental events such as droughts affect millions of people all around the world. Although it is not possible to prevent this type of event, its prediction under different time horizons enables the mitigation of eventual damages caused by its occurrence. An important variable for identifying occurrences of droughts is the sea surface temperature (SST). In the tropical Atlantic Ocean, SST data are collected and provided by the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA) project, which is an observation network composed of sensor buoys arranged in this region. Sensors of this type, and more generally Internet of Things (IoT) sensors, commonly lead to data losses that influence the quality of datasets collected for adjusting prediction models. In this paper, we explore the influence of temporal aggregation in predicting step-ahead SST considering different prediction horizons and different sizes for training datasets. We have conducted several experiments using data collected by PIRATA project. Our results point out scenarios for training datasets and prediction horizons indicating whether or not temporal aggregated SST time series may be beneficial for prediction. [ABSTRACT FROM AUTHOR]

In several domains, there has been an increasing interest in analysing moving objects due to the recent ubiquity of location tracking devices. These locations are commonly abstracted and stored as trajectories: a finite set of ordered in time geometries. Tracked objects tend to move in a certain environment that influences their movement behaviour. Time dependent environmental data are commonly abstracted and stored in grid/array structures that have different granularities and characteristics compare to the trajectory datasets. Movement analysis requires linking these two data types. However, little consideration has been given to the issues of integration in the moving objects databases that is primarily dealing with trajectory storage and analysis as well as in array databases dealing mainly with the storage and retrieval of grid structures. In this paper, we propose a database model that utilizes abstract data types for combining trajectories and time dependent environmental data. We introduce a set of spatio-temporal operations for interacting with raster data and integrating them with the moving geometries. We demonstrate how the integration operations can be used for manipulation and analysis of moving objects, using trajectories of tropical cyclone and environmental data, using sea surface temperature (SST) for the period from 1980 to 2009 as a case study. Since tropical cyclones generally gain strength over the warmer seas, the proposed operations are used to answer questions about genesis and movement patterns of tropical cyclones, in relation to the changing patterns of the SST. [ABSTRACT FROM AUTHOR]

The principle of electronic commutation makes brushless DC motors suitable for deep-sea application by sealing the motor in an oil-filled housing. However, if the oilfilled actuator is not designed properly, it will malfunction in the deep sea in spite of its excellent performance on land. In this paper, oil viscosity variations with pressure and temperature are reviewed because both factors vary with the operating depth, and a practical approach to estimate the viscous torque is advanced based on a viscous drag model of the selected motor and the properties of the oil. An experimental rig that can simulate the deep sea environment was developed, by which a series of experiments to study the motor efficiency and dynamic performance in different conditions were conducted. The values of viscous torque obtained in the experiments agreed well with our estimation. The low efficiency in the 2°C experimental group confirmed the influence of temperature, while the dramatic difference in the dynamic performance of the motor when filled with different oils verified the importance of analyzing the properties of the oil and of making a deliberate selection. [ABSTRACT FROM AUTHOR]

Long and temporal time-consistency rainfall time series are essential for studying climate; nevertheless, raingauge stations are unevenly distributed across southwestern Colombia. This research paper assesses the consistency of the satellite rainfall estimate from Climate Hazards Group Infrared Precipitation (CHIRPS) via pixel-to-point comparison with 46 observed monthly rainfall time series using four pairwise metrics and Combined Principal Component Analysis (CPCA). Two Combined Principal Components (CPC) were also used to determine the relationship with the Sea Surface Temperature (SST) through simultaneous linear correlation maps. The results showed that CHIRPS has a better performance in the Andean region than in the Pacific region. The correlation between CPC1 (CPC2) and SST showed a typical El Niño Southern Oscillation pattern with an inverse (direct) relationship between the rainfall in the Andean (Pacific) Region. Finally, our results validate that CHIRPS can be included in further studies of the spatiotemporal dynamics of rainfall in Southwestern Colombia. [ABSTRACT FROM AUTHOR]

This paper evaluates the global economic damage arising from the effects of climate change and associated carbon dioxide concentrations on the loss of coral reefs. We do this by first estimating the effects of sea surface temperature and carbon dioxide concentrations on coral cover. We develop a statistical relationship between coral coverage and sea surface temperature that indicates that the effects are dependent on the temperature range. For example, we find that increasing sea surface temperature causes coral coverage to decrease when sea surface temperature is higher than 26.85 °C, with the estimated reduction being 2.3% when sea surface temperature increases by 1%. In addition, we find that a 1% carbon dioxide increase induces a 0.6% reduction in global coral coverage. We also estimate the resultant loss in economic value based on a meta-analysis of the recreational and commercial value of reef coverage and a crude proportional approach for other value factors. The meta-analysis shows that the coral reef value decreases by 3.8% when coral cover falls by 1%. By combining these two steps we find that the lost value in terms of the global coral reef value under climate change scenarios ranges from US$3.95 to US$23.78 billion annually. [ABSTRACT FROM AUTHOR]

This paper explores how changes in sea surface temperature (SST) affect tuna catch in countries in the Eastern Pacific Ocean (EPO). We apply a production function approach to establish the relationship between SST and the catch of yellowfin (Thunnus albacares) and skipjack tuna (Katsuwonus pelamis) that use purse seines. We use data for 1° latitude/longitude grids within the exclusive economic zones of countries in the EPO. Catch of yellowfin and skipjack tuna increases with SST in all countries, with high values of catch recorded in the eastern coastal borders. The biggest increase in revenue from yellowfin and skipjack tuna as result on 1 °C increase in SST is for Mexico, while Kiribati had the smallest increase. However, if we adjust the increase in revenue by coastal population, the highest values are for Kiribati and French Polynesia. The higher tuna catch translates to higher government revenue from tuna fishing licenses, and more jobs for tuna fishers and those in the tuna processing industry in the state. However, the reduction on catch of other species may offset the positive effects on tuna catch, and may even result in a negative impact overall. We highlight the importance of conducting research on SST that is specific to species, gear, and location to fully account for the impact of ocean warming. [Display omitted] • Ocean warming affect tuna catch in countries in the Eastern Pacific Ocean. • Catch of yellowfin and skipjack tuna increases with sea surface temperature in all countries. • Highest additional revenue per coastal population are for Kiribati and French Polynesia. • The reduction on catch of other species may offset the positive effects on tuna catch. • Research must be specific to species, gear, and location to fully account for the impact of ocean warming. [ABSTRACT FROM AUTHOR]

• An AWHP based combined cooling and desalination system is proposed. • Low-grade waste heat is recovered from AWHP to be used for desalination step. • A bio-fueled combined cycle is used for powering both AWHP and hospital equipment. • Use of biofuel and air to water heat pump leads to a significant reduction in CO footprints. • Sensitivity of GOR to dehumidifier/humidifier effectiveness, air humidity, top/bottom temperature is analyzed. This paper presents a trigeneration facility based on a biogas driven gas turbine cycle for electricity production and an air to water heat pump for simultaneous extraction of cooling and potable water, and evaluates its robustness and effectiveness under different climatic conditions and variable demands. The air to water heat pump, which consists of an inside evaporator fan, expansion device, condenser, evaporator, and a compressor, is installed for supplying the cooling load of a hospital building in summer. In the refrigeration cycle, R134a absorbs heat from the inside warm air for space cooling and releases it to the saline water for driving a desalination process. Maximum values of cooling and electrical demands of a standard hospital building, where is located in south of Iran, over the hottest day of 2018 are considered for the worst case implementation. Engineering equation solver and general algebraic mathematical modeling system are employed to develop the non-linear optimization strategy, find the best operating point of the air to water heat pump based trigeneration plant, and minimize its energy cost under the greatest load level. Moreover, the sensitivity of the gained output ratio of desalination cycle to the relative humidity of the air entering and leaving the humidifier, the dehumidifier and humidifier effectiveness, and the top and bottom temperatures are comprehensively analyzed. The relative humidity of air entering the humidifier and the larger dehumidifier effectiveness have the significant effects on increasing the gained output ratio of the desalination cycle. Due to intense solar irradiation in summer, the seawater temperature naturally increases, which results in larger gained output ratio and higher mass flow rate of pure water. [ABSTRACT FROM AUTHOR]

Radiant heat gain severely endangers thermal comfort and dramatically increases building energy consumptions in a tropical outdoor urban environment. To rapidly evaluate outdoor thermal features, this paper presents a three-dimensional integrated numerical model to assess building surface temperature and mean radiant temperature (MRT) in typical outdoor industrial environments of Singapore. For proper accounting of solar irradiance and radiant heat fluxes, Perez all-weather model and finite volume discrete ordinates method (fvDOM) are integrated into numerical code. Under the climate conditions of Singapore, i.e., light wind and intense solar irradiance, the model adopts a daily-average convection coefficient to simplify air dynamics to solve the surface energy balance equation so that the model efficiency can be significantly improved. Surface thermal load computed using the model has been validated by the on-site measurement for a contemporary and a matured industrial building on two sunny days. By comparing simulated and measured results, the corresponding coefficient of determination (R 2) and the refined index of agreement (RIA) are respectively > 0.99 and > 0.8 to indicate that the model agrees well with the measurement. Also, the model is used to predict the MRT map around the industrial environment and to demonstrate that tree shading reduces mean MRT of 6.3 °C for daily-average and 13.29 °C at noon in a street canyon under a 25% greenery coverage ratio. Image 1 • Rapidly assess building surface temperature and mean radiant temperature. • Tropical industrial environments. • Intense solar irradiance and low wind speed. • Daily-average convection coefficient based on measurement. • Calculated surface temperature has been validated by the on-site measurement. [ABSTRACT FROM AUTHOR]