Sea Surface Temperature Values Research Articles

Loggerhead marine turtle (Caretta caretta) ecological facts from a trophic relationship model in a hot spot fishery area: Gulf of Ulloa, Mexico

The oceanographic conditions in the Gulf of Ulloa (GU) region make a distinctive faunal assemblage, allowing the presence of species both ecologically and economically important. Constant interaction of emblematic species with the fishing activity has brought social and conservation problems due to the lack of ecological information and/or management tools. For the loggerhead turtle (Caretta caretta), the GU is an important feeding area, so the interaction with anglers is frequent. In this sense, some events of high loggerhead mortality have resulted in restrictive fishing measures; nevertheless, alternative hypotheses should be explored to explain this fact better. With the purpose of not only knowing the ecosystem ecological attributes but also obtaining specific ecological facts of the loggerhead turtle – as instantaneous total mortality – this study proposes Ecopath with Ecosim (EwE) model by calculating Allen's approximation of production to biomass ratio (P/B). Using the thermoregulation theory of ectotherms and this baseline model, the scenarios were run in Ecosim combining two forcing factors (FF): sea surface temperature (SST) and different fishing effort (F) values. All Ecosim scenarios were run over 30 simulated years taking the (P/B) values of the loggerhead turtle. According to the results in this study, the model allowed us to obtain specific ecological attributes for C. caretta, particularly for the P/B estimates in different simulation scenarios, which showed that colder sea surface temperature increases loggerhead mortality. All the information combined provided a better panorama to understand the role this turtle has within the Biological Action Center of the GU system and its interaction with other activities developed on site, such as fishing.

Summer season sea surface temperature changes in the Aegean Sea based on 30years (1989-2019) of Landsat thermal infrared data.

In this research, sea surface temperature (SST) variability for the summer season in the Aegean Sea was analysed over a period of 30years by using the Landsat thermal infrared bands. A total of 88 Landsat 5, 7, and 8 thermal infrared satellite images from June, July, and August were used for each year from 1989 to 2019. To estimate SST from the thermal infrared band data, thermal infrared sensor at-sensor spectral radiance, and thermal infrared sensor top-of-atmosphere brightness temperatures were used. SST pixel values were extracted from thermal images for the 3-month summer season of each year. In order to validate the findings, regression analysis was performed between the Mediterranean Sea Ultra High Resolution SST L4 data and Landsat data for the 2008-2019 period. Regression constant R-squared values were found to be 0.9672 for June, 0.9550 for July, 0.9634 for August, and 0.9634 for all summer seasons. It was calculated that the minimum value of the average SST was 18.44 ± 2.87°C in 1992, and the maximum value of the average SST was 23.45 ± 0.70°C in 2018. According to the Landsat data, over the past 30years, the annual average SST changes were estimated to be 0.11°C, and the total changes of average SST were estimated to be 3.19 ± 1.26°C. As a result of the analysis and the validation, we can see that there is a rising trend in sea surface temperature in the Aegean Sea. However, it is difficult to determine whether this upward trend is related to global climate change.

Nearshore paleoceanogaphic conditions through the Holocene: Shell carbonate from archaeological sites of the Atacama Desert coast

From the southern coast of Peru to the central-north coast of Chile (18°-31°S) previous evidence suggests that wide variations in sea surface temperature (SST) over the Holocene may be associated with changes in coastal upwelling regimes along the region. Support for spatial contrasts and similarities in oceanographic dynamics comes from earlier work at both extremes of the region. Using a 12 kyr record derived from shell midden archaeological sites around Taltal Chile (25°S), we show that changes in the region are not necessarily consistent with a simple latitudinal gradient. Using δ13C and δ18O isotopic records from archaeological carbonate shells of the keyhole limpet Fissurella maxima we find that cold SST during the Early Holocene was associated with more negative δ13C values in agreement with observations from southern Peru. Warmer waters during the beginning of the Middle Holocene, had positive δ13C values, differentiating them from southern Peru and central-north Chile records. The rest of the Middle Holocene showed a decreasing SST accompanied by negative δ13C values, and after 4000 cal yr BP, the Late Holocene showed a progressive increase in SST and positive δ13C values. Finally, modern carbonate shells of F. maxima indicate a situation not observed throughout the Holocene period: warm SST is associated with negative δ13C values, in line with results on modern shells from southern Peru and modern oceanographic patterns that indicate an intensification of coastal upwelling with events of warm water intrusion. Our results show that the southern coast of the Atacama Desert experienced important fluctuations in SST and upwelling conditions during the Holocene, which may have affected the distribution of nearshore fisheries along the Northern Coast of Chile.

Response of Tropical Cyclone Formation and Intensification Rates to Climate Warming in Idealized Simulations

AbstractThere is currently no theory for the rate of tropical cyclone (TC) formation given a particular climate, so our understanding of the relationship between TC frequency and large‐scale environmental factors is largely empirical. Here, we explore the sensitivity of TC formation and intensification rates to climate warming in a series of highly idealized cloud‐permitting simulations, in which TCs form spontaneously from a base state of rest on an f‐plane. The simulations reveal a nonmonotonic relationship between the time taken for a TC precursor disturbance (a “seed”) to form and the prescribed sea surface temperature (SST), with moderately long seed emergence times at both ends of the SST range tested (292 and 304 K) and a shorter seed emergence time at the middle value of SST (298 K). Genesis potential indices (GPIs) exhibit a different response to warming: either a monotonic increase if the potential intensity and midtropospheric relative humidity are used or relatively little sensitivity if the saturation deficit is used as the humidity variable. The sensitivity of elapsed time between a TC seed disturbance and TC genesis to surface warming is, however, generally well captured by GPIs, especially those that depend on the saturation deficit. The maximum intensification rate of TCs increases strongly with warming, particularly during the second half of the intensification process. Notably, storms intensify much more rapidly with increasing temperature than is predicted by extant theory based on potential intensity, suggesting that TCs in a warmer climate may intensify even more rapidly than recent studies suggest.

Study of Sea Surface Temperature (SST), Does It Affect Coral Reefs?

HighlightEffect of sea surface temperature on coral reefsCorrelation with NOAA and AQUA MODIS satellite imagery dataSea water quality analysisThe adaptability of coral reefsAbstractThis research aims to identify the influence of Sea Surface Temperature (SST) to coral disease and bleaching using MODIS-Aqua data from 2003-2009 and NOAA Coral Reef Watch data. Field-data collection on coral disease and bleaching was carried out in Bunaken National Park, Wakatobi National Park, and Raja Ampat, in August, October, and November 2009, respectively. The presence of coral disease and bleaching was observed by using time-swim method. A prevalence formula was used to calculate the percentage of coral disease and bleaching colonies. The range of mean SST value from each location: Bunaken from 26.84-31.45oC, Wakatobi from 26.09-31.95oC and Raja Ampat from 27.72-31.36oC. There is an influence of SST anomaly on the presence of dis- ease and coral bleaching. During 2003-2019, the highest SST anomaly that could increase the risk of the coral bleaching phenomenon was found in 2010. Coral disease and bleaching were found at locations with high SST anomaly, low nitrate and available phosphate. However, high SST anomalies were not a main cause of coral disease and bleaching. In many locations in Indonesia, mass-bleaching has occurred and the ability of coral adaptation is the main key in dealing with this phenomenon.

Intraspecific size variation in planktonic foraminifera cannot be consistently predicted by the environment.

The size structure of plankton communities is an important determinant of their functions in marine ecosystems. However, few studies have quantified how organism size varies within species across biogeographical scales. Here, we investigate how planktonic foraminifera, a ubiquitous zooplankton group, vary in size across the tropical and subtropical oceans of the world. Using a recently digitized museum collection, we measured shell area of 3,799 individuals of nine extant species in 53 seafloor sediments. We first analyzed potential size biases in the collection. Then, for each site, we obtained corresponding local values of mean annual sea‐surface temperature (SST), net primary productivity (NPP), and relative abundance of each species. Given former studies, we expected species to reach largest shell sizes under optimal environmental conditions. In contrast, we observe that species differ in how much their size variation is explained by SST, NPP, and/or relative abundance. While some species have predictable size variation given these variables (Trilobatus sacculifer, Globigerinoides conglobatus, Globigerinella siphonifera, Pulleniatina obliquiloculata, Globorotalia truncatulinoides), other species show no relationships between size and the studied covariates (Globigerinoides ruber, Neogloboquadrina dutertrei, Globorotalia menardii, Globoconella inflata). By incorporating intraspecific variation and sampling broader geographical ranges compared to previous studies, we conclude that shell size variation in planktonic foraminifera species cannot be consistently predicted by the environment. Our results caution against the general use of size as a proxy for planktonic foraminifera environmental optima. More generally, our work highlights the utility of natural history collections and the importance of studying intraspecific variation when interpreting macroecological patterns.

Comparison of the Sentinel-3A and B SLSTR Tandem Phase Data Using Metrological Principles

The Sentinel-3 mission is part of the Copernicus programme space segment and has the objective of making global operational observations of ocean, land and atmospheric parameters with its four on-board sensors. Two Sentinel-3 satellites are currently on orbit, providing near-daily global coverage. Sentinel-3A was launched on 16 February 2016 and Sentinel-3B on 25 April 2018. For the early part of its operation, Sentinel-3B flew in tandem with Sentinel-3A, flying 30 s ahead of its twin mission. This provided a unique opportunity to compare the instruments on the two satellites, and to test the per pixel uncertainty values in a metrologically-robust manner. In this work, we consider the tandem-phase data from the infrared channels of one of the on-board instruments: the Sea and Land Surface Temperature Radiometer, SLSTR. A direct comparison was made of both the Level 1 radiance values and the Level 2 sea surface temperature values derived from those radiances. At Level 1, the distribution of differences between the sensor values were compared to the declared uncertainties for data gridded on to a regular latitude-longitude grid with propagated pixel uncertainties. The results showed good overall radiometric agreement between the two sensors, with mean differences of ∼0.06 K, although there was a scene-temperature dependent difference for the oblique view that was consistent with what was expected from a stray light effect observed pre-flight. We propose a means to correct for this effect based on the tandem data. Level 1 uncertainties were found to be representative of the variance of the data, expect in those channels affected by the stray light effect. The sea surface temperature results show a very small difference between the sensors that could be in part due to the fact that the Sentinel-3A retrieval coefficients were also applied to the Sentinel-3B retrieval because the Sentinel-3B coefficients are not currently available. This will lead to small errors between the S3A and S3B retrievals. The comparison also suggests that the retrieval uncertainties may need updating for two of the retrieval processes that there are extra components of uncertainty related the quality level and the probability of cloud that should be included. Finally, a study of the quality flags assigned to sea surface temperature pixel values provided valuable insight into the origin of those quality levels and highlighted possible uncertainties in the defined quality level.

Establishment of AIRS climate-level radiometric stability using radiance anomaly retrievals of minor gases and sea surface temperature

Abstract. Temperature, H2O, and O3 profiles, as well as CO2, N2O, CH4, chlorofluorocarbon-12 (CFC-12), and sea surface temperature (SST) scalar anomalies are computed using a clear subset of AIRS observations over ocean for the first 16 years of NASA's Earth-Observing Satellite (EOS) Aqua Atmospheric Infrared Sounder (AIRS) operation. The AIRS Level-1c radiances are averaged over 16 d and 40 equal-area zonal bins and then converted to brightness temperature anomalies. Geophysical anomalies are retrieved from the brightness temperature anomalies using a relatively standard optimal estimation approach. The CO2, N2O, CH4, and CFC-12 anomalies are derived by applying a vertically uniform multiplicative shift to each gas in order to obtain an estimate for the gas mixing ratio. The minor-gas anomalies are compared to the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ESRL) in situ values and used to estimate the radiometric stability of the AIRS radiances. Similarly, the retrieved SST anomalies are compared to the SST values used in the ERA-Interim reanalysis and to NOAA's Optimum Interpolation SST (OISST) product. These intercomparisons strongly suggest that many AIRS channels are stable to better than 0.02 to 0.03 K per decade, well below climate trend levels, indicating that the AIRS blackbody is not drifting. However, detailed examination of the anomaly retrieval residuals (observed – computed) shows various small unphysical shifts that correspond to AIRS hardware events (shutdowns, etc.). Some examples are given highlighting how the AIRS radiance stability could be improved, especially for channels sensitive to N2O and CH4. The AIRS shortwave channels exhibit larger drifts that make them unsuitable for climate trending, and they are avoided in this work. The AIRS Level 2 surface temperature retrievals only use shortwave channels. We summarize how these shortwave drifts impacts recently published comparisons of AIRS surface temperature trends to other surface climatologies.

Oceanographic Determinants of the Abundance of Common Dolphins (Delphinus delphis) in the South of Portugal

Off mainland Portugal, the common dolphin (Delphinus delphis) is the most sighted cetacean, although information on this species is limited. The Atlantic coast of Southern Portugal is characterized by an intense wind-driven upwelling, creating ideal conditions for common dolphins. Using data collected aboard whale-watching boats (1929 sightings and 4548 h effort during 2010–2014), this study aims to understand the relationships between abundance rates (AR) of dolphins of different age classes (adults, juveniles, calves and newborns) and oceanographic [chlorophyll a (Chl-a) and sea surface temperature (SST)] variables. Over 70% of the groups contained immature animals. The AR of adults was negatively related with Chl-a, but not related to SST values. The AR of juveniles was positively related with SST. For calves and newborns, although the relationship between SST and AR is similar to that observed for juveniles, the effect could not be distinguished from zero. There was no relationship between Chl-a levels and the AR of juveniles, calves and newborns. These results corroborate previous findings that common dolphins tend to occur in highly productive areas demonstrating linkages between their abundance and oceanographic variables, and that this region may be a potential nursery ground.

A Warming Mediterranean: 38 Years of Increasing Sea Surface Temperature

The Mediterranean basin has been classified as a hot-spot for climate change. The Mediterranean Sea plays a fundamental regulatory role in the regional climate. We have analyzed the largest available and complete time series (1982–2019) of blended sea surface temperature (SST) data to study its seasonal cycle and look for a possible warming trend in the basin. From the analysis of the Mediterranean mean SST time series, a new temporal seasonal division is derived that differs from the one used in atmospheric climatology. Then, the SST time series were decomposed into their seasonal and trend components, and a consistent warming trend of 0.035 °C/year was obtained. The nature of this trend has been investigated, indicating a higher warming trend for both maximum and high/summer SST values than for the winter/colder ones. This reinforces the consistency of the SST increase since it is not only based on the presence of extreme values, but on a homogeneous basin global increase of high SST records as well. Although warming is found throughout the Mediterranean basin, the spatial variability found leads to the division of the basin into three distinct subareas regarding warming.

Relative Roles of Eurasian Snow Depth and Sea Surface Temperature in Indian and Korean Summer Monsoons Based on GME Model Simulations

AbstractIndian Summer Monsoon (ISM) and East Asian Summer Monsoon (EASM) are the most important weather systems in India and Korea respectively. The interannual variations of ISM and EASM largely depend on the anomalies of sea surface temperatures (SSTs) of Tropical Equtorial Pacific and Indian Ocean and also on the Eurasian Snow Depth/Cover. In this study, the relative roles of these two most important surface boundary conditions on the Indian and Korean monsoons have been examined using the high resolution (40 km) global numerical weather prediction model of German Weather Service (GME). Four sets of experiments were carried out by varying the climatological and observed values of SSTs and snow. This study shows that there is a negative (positive) relationship between the Western (Eastern) Eurasian snow depth and ISMR, whereas a positive (negative) relationship between the Western (Eastern) Eurasian snow depth and Korean monsoon rainfall has been observed. Results show that when observed SST and snow are prescribed to the model as boundary conditions, the simulated winds and rainfall are close to the NCEP/NCAR reanalyzed winds and GPCP rainfall, respectively. This study reveals that the model simulated summer monsoons in Indian and Korean domains are not good enough unless an observed Eurasian snow is prescribed in addition to the observed SST.

Seasonal variation of key environmental parameters in the Sea of Oman using EO data and GIS

In this study, the seasonal and annual changes of key environmental parameters in the Sea of Oman during the period 2005–2012 have been investigated using a range of Earth Observation datasets. Furthermore, the seasonal and spatial variability of those changes to other environmental parameters for the same time period was also explored. Analysis of census of the anti-cyclonic and cyclonic eddies using the Okubo–Waiss algorithm was carried out in a Geographical Information Systems environment using the Marine Geospatial Ecology Tools. Results indicated that the Sea of Oman is mostly influenced by seasonality and by location. The Spearman’s rank correlation test shows a strong, negative correlation between Sea Surface Temperature (SST) and Chlorophyll-a (Chlor-a) in most parts of the sea during the studied period. In terms of spatial variations, eastern parts of the sea showed higher Chlor-a concentrations and lower SST values, especially during summer. The Okubo–Waiss algorithm revealed the existence of 337 eddies, 180 of which are anti-cyclonic eddies with general life span ranging from 4 to 43 weeks, while years 2008 and 2010 presented the most cyclonic eddies. The presence and duration of these eddies proved to be a great contributor in water mixing in the region. Our results clearly demonstrated that this integrated approach improved our understanding of the sea-atmosphere dynamics and environmental variability of the studied region.

Atmospheric Forcing of the High and Low Extremes in the Sea Surface Temperature over the Red Sea and Associated Chlorophyll-a Concentration

Taking advantage of 37-year-long (1982–2018) of high-quality satellite datasets, we examined the role of direct atmospheric forcing on the high and low sea surface temperature (SST) extremes over the Red Sea (RS). Considering the importance of SST in regulating ocean physics and biology, the associated impacts on chlorophyll (Chl-a) concentration were also explored, since a small change in SST can cause a significant impact in the ocean. After describing the climate features, we classified the top 5% of SST values (≥31.5 °C) as extreme high events (EHEs) during the boreal summer period and the lowest SST values (≤22.8 °C) as extreme low events (ELEs) during the boreal winter period. The spatiotemporal analysis showed that the EHEs (ELEs) were observed over the southern (northern) basin, with a significant warming trend of 0.027 (0.021) °C year−1, respectively. The EHEs were observed when there was widespread less than average sea level pressure (SLP) over southern Europe, northeast Africa, and Middle East, including in the RS, leading to the cold wind stress from Europe being relatively less than usual and the intrusion of stronger than usual relatively warm air mass from central Sudan throughout the Tokar Gap. Conversely, EHEs were observed when above average SLP prevailed over southern Europe and the Mediterranean Sea as a result of the Azores high and westward extension of the Siberian anticyclone, which led to above average transfer of cold and dry wind stress from higher latitudes. At the same time, notably less wind stress due to southerlies that transfer warm and humid air masses northward was observed. Furthermore, physical and biological responses related to extreme stress showed distinct ocean patterns associated with each event. It was found that the Chl-a concentration anomalies over the northern basin caused by vertical nutrient transport through deep upwelling processes are the manifestation of the superimposition of ELEs. The situation was the opposite for EHEs due to the stably stratified ocean boundary layer, which is a well-known consequence of global warming.

Weekly sea surface temperature from SNPP-VIIRS data using open source software

The objective of this study is to make weekly mean sea surface temperature (SST) from SNPP-VIIRS satellite data. The data used were SST data every afternoon pass, from 13 to 19 May 2019. The data were obtained from Remote Sensing Technology and Data Center, LAPAN. From 12 samples data used showed that pixel size of each data are different, with range between 0.006737548 - 0.006858158 degree. The pixel size should be exactly the same to do data overlay. Then, the pixel size was resized become 0.00675 degree. This process was carried out using Reprojection Menu in QGIS software. The next process was calculating weekly mean SST every pixel. The mean SST was calculated only on pixels that have SST values. The calculation was not carried out on cloud, cloud shadow, land, and out of coverage data. The tolerance of coordinate position between pixels are less than 0.5 of pixel size. Weekly mean SST calculation process was executed using mean function in R software. The result of mean SST showed some possible error SST values. The errors were found in these conditions: 1) in coastal areas where possible mixed pixels of land and water 2) near cloud, where possible mixed pixel of cloud, cloud shadow, and water, 3) pixels with (extremely) high SST values near clouds. To overcome these conditions, some median type filters were applied. Therefore, weekly mean SST from SNPP-VIIRS data that smooth and minimum cloud cover can be obtained.

Prediction of potential fishing zones for mackerel tuna (Euthynnus sp) in Bali Strait using remotely sensed data

Mackerel tuna (Euthynnus sp.) is one of the pelagic fish species that has become the export commodity of Indonesia. This species is a carnivorous marine biota that forms a group with rapid swimming abilities. Mackerel tuna is scattered throughout Indonesian waters, including the waters of the Bali Strait. This study aims to predict Mackerel tuna fishing zone in the Bali Strait by using remotely sensed data. Sea surface temperature (SST) and sea surface chlorophyll-a (chl-a) were downloaded from the ocean colour website meanwhile the fishing catches obtained from nusantara fisheries port (pelabuhan perikanan nusantara) Pangembangan, Bali and the fishing lane from marine research and observation agency (balai riset dan observasi laut), Bali. The results showed that the highest of fishing catches occurred in September and October with SST value of 26 – 28 °C and chl-a value of 0.4 – 2.6 mg/m3. Based on the SST and chl-a value, the results revealed the potential fishing zone of Mackerel tuna mostly occurred during south monsoon (April - September). In general, the distribution of Mackerel tuna, based on the overlaid SST and chl-a, showed moderate spatial correlation with actual fishing locations from local fisherman. Integration in situ data and oceanographic condition generated from remotely sensed data could form the basis for fisheries management and information system, such as Mackerel in Bali Strait.

Relationships Among SST Variability, Physical, and Biological Parameters in the Northeastern Indian Ocean

ABSTRACT This study modelled physical and biological changes in the Bay of Bengal, the Arabian Sea, and the exclusive economic zone around Sri Lanka by examining the relationships between sea surface temperature (SST) and a range of biological and physical variables allowing prediction of the changes in the variables studied with changing temperature. Datasets were extracted from satellite data from 2003 to 2015. Boosted regression trees (BRT) were used to model the data and identify their (non-linear) relationships. Within the study region and based on the BRT model, nitrate, latent heat flux, wind speed, and chlorophyll a (chl a) concentration in open water were found to have negative relationships with SST, while air temperature and ozone mass mixing ratio had positive relationships. Seasonal peak values of wind speed and chl a concentrations occurred from June to August. Peak SST and air temperature values occurred from March to May, peak nitrate and latent heat values from September to November, and peak ozone mass mixing ratios from December to February. The highly correlated ranges of air temperature, nitrate concentration, open water latent energy flux, surface wind speed, chl a concentration, and ozone mass mixing ratio for SST above 28°C were 299–300.5 K, >0.2 µmol L−1, 120–160 W m−2, 4–8 m s−1, 0.1–1 mg m−3, and 4.5–5.5 × 10−8, respectively.

Growing Up Down South: Spatial and Temporal Variability in Early Growth of Fuegian Sprat Sprattus fuegensis From the Southwest Atlantic Ocean

The Fuegian sprat Sprattus fuegensis represents one of the most important pelagic resources in the Southwest Atlantic Ocean (SWAO), exerting a crucial ecological role as an intermediary link in Patagonian food webs. Otolith microstructure of 217 age-0 sprats were analyzed aiming to characterize growth patterns and possible environmental effects over them. Samples were gathered during three oceanographic surveys (spring 2014; autumns 2016, 2017) in Tierra del Fuego (TDF) and the Marine Protected Area Namuncura-Burdwood Bank (MPAN-BB), the first Argentinian open-sea marine protected area. Daily growths (DG) of larvae and post-larvae were estimated by individually modeling size and otolith radius relationships through back-calculation procedures using potential and linear functions respectively. Increment widths (IW) and DG values and trajectories were assessed for older sprats (i.e. survivors) sampled in the autumn surveys considering the habitat, year sampled and sprats’ hatching seasons, and were additionally evaluated in relation to sea-surface temperature (SST). IW and DG trajectories differed primarily according to the habitat sampled and sprats’ hatching seasons. Overall, strong coupling was detected between IW and DG trajectories with SST in both habitats. However, statistical assessment on particular comparisons showed that this general trend is not strictly invariant. Even though several results pinpointed a positive correlation between IW and DG with SST, the highest DG were estimated for summer- and autumn-born sprats sampled in 2016 in the MPAN-BB, period and habitat with the lowest SST values. These results unveil a complex relationship between spatial and temporal variability during early growth of Fuegian sprats, supplying relevant information that could be used in the creation of adequate ecosystem based management strategies in the SWAO.

RESPONS SUHU PERMUKAAN LAUT DAN KLOROFIL-A TERHADAP KEJADIAN ENSO DAN IODM DI WILAYAH INDO-PASIFIK TROPIS

Fenomena anomali laut-atmosfer antar-tahunan dari El Nino Southern Oscillation (ENSO) dan Indian Ocean Dipole Mode (IODM) di wilayah Indo-Pasifik Tropis memberikan dampak pada ekosistem laut, hidrologi dan variabilitas iklim. Penelitian ini bertujuan untuk menganalisis pola spasial dan variabilitas temporal suhu permukaan laut (SPL) dan klorofil-a permukaan (Chl-a) terkait dengan ENSO dan IODM di Indo-Pasifik Tropis. Data deret waktu bulanan dari tahun 1980-2017 (37 tahun) diperoleh dari pusat data global, dan dianalisis menggunakan metode empirical orthogonal function (EOF). Hasil penelitian menunjukkan nilai tiga terbesar pertama dari SPL (Chl-a) menjelaskan 81,7% (76%) dari total explained variance. Struktur spasial SPL mode-1 (56%) membentuk seperti dua kutub asimetris antara timur dan barat Pasifik Tropis dengan pola yang berbeda di lepas Pantai Peru. Pola ini diduga berhubungan dengan tahun normal atau La Nina. Selanjutnya, kondisi EL Nino dan IODM diduga tergambarkan oleh SPL mode-2 (19%), dengan fase negatif dominan di atas ekuator Pasifik dan menghilangnya area upwelling di lepas Pantai Peru.

Distribution of whale shark (Rhincodon typus) off northern Peru based on habitat suitability

Abstract In the south‐eastern Pacific Ocean, few studies of whale sharks (Rhincodon typus) exist. In Peru, the northern coast has been identified as the area with the highest presence of whale sharks, yet their ecology in this area is poorly defined. This study predicts the spatial distribution of whale sharks off coastal northern Peru (03°00′S–04°30′S) during La Niña and El Niño seasonal conditions, utilizing maximum entropy modelling. Between 2009 and 2018 (except for 2011), 347 whale sharks were geo‐referenced in northern Peru with greatest data recordings in the austral summer and spring during La Niña events. Depth was the most important predictive variable for spatial distribution of whale sharks, followed by chlorophyll‐a. Sharks were predicted in shallower coastal waters in which chlorophyll‐a values are higher. Habitat suitability was higher in the northern coastal part of the study area. Spring presents the most suitable environmental conditions for whale sharks, both during La Niña and El Niño conditions. The probability of whale shark presence in the north of Peru increases at higher chlorophyll‐a and sea surface temperature values. Therefore, whale sharks appear to aggregate seasonally in northern Peru, potentially exploiting rich foraging grounds. In these areas of high suitability, whale sharks are susceptible to fisheries, bycatch, ship collisions, unmanaged tourism, and pollution; thus, management actions should focus in these areas. This study represents a first step to understand the distribution and habitat suitability of whale shark in Peruvian waters. Further studies should identify suitable habitat for whale sharks in offshore areas. Also, these should focus on the connectivity of these aggregations with other localities in the south‐eastern Pacific in order to contribute to regional strategies for the conservation of this iconic species in this particular region.

The Study of the State of the World Ocean Areas Based on Modern Technologies for Processing and Analysing Data

This paper is devoted to the processing of hydrophysical data on the state of marine areas utilizing modern data processing technologies. Author uses Python programming language to process marine data. The results on the processing of the remote sensing data on the Baltic and the Black Seas surface temperature are presented in the study. Daily satellite data for the years 1982–2018 were processed using Python scripts for both water areas. The analysis of the obtained information was conducted with R programming language. This language supports a wide range of statistical and numerical methods and is convenient to use to determine the statistical characteristics of the studied quantities. Data analysis reveals statistically significant positive trend in the sea surface temperature (SST) values in the both studied water areas over the past decades. The paper has also analyzed the spatial variability of the surface temperature within considered areas. The analysis illustrates the temperature variability in certain areas of the sea and identifies areas with the highest rate of temperature increase. Conclusions are made on the usability of the programming languages for various data processing tasks.