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Introduction: The North Pacific of Costa Rica is characterized by presenting a variation of the subsurface temperature of the sea (SSST) modulated by surface winds with east component, with seasonal and intra-seasonal variations. The SSST is fundamental for the interactions of the ocean-atmosphere interface and influence marine biological processes. Zooplankton studies in the North Pacific are scarce and have been focused on the composition, abundance and biomass of macro and mesozooplankton in Culebra Bay. No works on zooplankton has been carried out northward of Papagayo Gulf. Objective: To analyze the variation of the zooplankton in Bahía Salinas at different scales in response to oceanographic-atmospheric conditions. Methods: during 2011, 2012 and 2013, mesozooplankton was collected in seven stations following a coastalocean gradient to determine abundance, biomass, and community composition. CTD casts were also carried out in each station. Hourly data of the Sea Subsurface Temperature (SSST) were obtained from June 2003 to December 2017. Results: The annual surface temperature in Bahía Salinas was lower in December-April with a secondary minimum in July and higher in May-June and August-November. The cold, neutral and warm events determined by anomalies in the SSST, presented a distribution of the temperature in the water column with horizontal stratification, vertical mixture and homogeneous, respectively. The spatial distribution of zooplankton did not show significant differences and the variation of the total average abundance and biomass showed a similar behavior during the study period, with less variation in the first year compared to the second one, being the copepods the predominant category for all the dates. On a seasonal scale, a general pattern of variation between dry and rainy seasons was not observed, and copepods and others zooplankton groups were the categories that presented differences. On an intra-seasonal scale, abundance and biomass showed an inverse relationship with SST. Copepods and gelatinous zooplankton (GZ) were differentiated in all events. Conclusions: The zooplankton of Bahía Salinas respond differentially at different scales to the climatic conditions that affect the SSST of the region. The classification of the sampling dates into events allows characterizing different profiles in the water column it also allows to define the variation patterns for mesozooplankton that reflects short-term adaptation as a function of variation in environmental conditions. These findings help to understand how oceanographic processes determine plankton community composition and biota in general. This is relevant in times of climate change and the manifestation of its impact through processes such as ocean acidification and loss of marine biodiversity. [ABSTRACT FROM AUTHOR]

The sea breeze is a mesoscale circulation on the coast driven by the differential heating between the land and sea. Here, the sea breeze in Uruguay is characterized using data of 8 coastal meteorological stations, as well as satellite and reanalyses data sets in the period 2011-2016. A sea breeze identification index was developed using wind speed and direction at 08:00 and 16:00 local time. An average of 60 days per year was found, ranging between 51 and 71 days. Sea breeze occurs twice as often in summer, and February and March show the largest variability in the number of days with sea breeze. The sea breeze develops for sea level pressure values ranging between 1000 and 1023 hPa, weak synoptic pressure gradient, and predominance of clear skies. Consecutive days with breeze (2-7 days) are usually associated with the passage of high pressure systems in the southwestern Atlantic or with atmospheric blocking. When there is sea breeze, it tends to occur along the entire Uruguayan coast. Nonetheless, there are differences in sea breeze development between the estuary and the oceanic regions due to the differences in air-sea coupling and the orientation of the coast in relation to the prevailing northeasterly winds. On average, the sea breeze starts at 11:00 (12:00) local time in the oceanic (estuarine) coast and has a southeasterly (southerly), reaching a maximum speed of 7.1 m.s-1 near 16:00. In several cases with sea breeze, cumulus-type cloudiness can be distinguished associated with the breeze front. [ABSTRACT FROM AUTHOR]

The ocean-atmosphere interaction acts as a force for hydrological systems at different time scales, El Niño-Southern Oscillation (ENSO) being one of them. this paper presents the analysis of hydrometeorological variables and their association with the Oceanic Niño Index (ONI), representative of ENSO, in the Upper Basin of Neuquén River (UBNR) for the period 2000-2014; detecting a weak correlation (r of 0,35). Precipitation, temperature and SWE presented weak and moderate associations, with a r lower than 0.44, 0.23 and 0.36 respectively, without a defined behavior for the different phases of ENSO; while the SCA presented a very weak correlation, between -0.07 and 0.14. Correlation between the flow and the ONI was 0.51 for the entire period and 0,31 for the El Niño phases with a 5% of significance, without being significant for La Niña periods. [ABSTRACT FROM AUTHOR]

The spatial and temporal variability of the annual cycle of chlorophyll-a in the Juan Fernandez archipelago is analyzed through eight years of satellite data of chlorophyll-a, wind, currents and sea level. This archipelago consists of three islands: Robinson Crusoe-Santa Clara (RC-SC) and Alexander Selkirk (AS). The RC-SC islands are in a region of high eddy kinetic energy and higher concentrations of chlorophyll-a, defined as Coastal Transition Zone, whereas the AS island is in a region with low eddy kinetic energy and lower concentrations of chlorophyll-a called Oceanic Zone. RC-SC has an increase in chlorophyll-a concentrations on the southwest side, while AS has its highest concentrations on the west side, indicating the presence of different forcing. On both islands the annual cycle of chlorophyll is significant and begins to increase in April, reaching relatively high values between June and November, decreasing to its lowest values in December, reaching a minimum in late March. This annual cycle does not appear related with the wind, but it appears related with the eddy kinetic energy. The increase of chlorophyll-a in winter is associated with mesoscale eddies coming from continental region, while spring increases could be associated with local processes linked to the "island mass effect". On both islands, it appears a significant increase in chlorophyll-a in the annual and bi-annual bands, but only in AS was found a significant inter-annual fluctuation linked with the El Niño and the Southern Oscillation. [ABSTRACT FROM AUTHOR]

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The interactions among the sea surface temperature in the Oceans Atlantic and Pacific and the atmospheric convergence of the Alisios winds from north and south, they give anomalies as a result in the precipitations of the Caribbean region. This convergence is the responsible for the climatic variability in the area (extreme events) that bears to global changes, to changes in other spheres and natural resources. Specifically the goal in this research is to analyze the influence of the climate variability in the soil resource, particularly in the Cuyaguateje basin in the west of Cuba. In Cuba specifically in the Cuyaguateje River basin, the increments in rainfall records and erosivity in the eighty decade has been significant in comparison with the decades of the years 1960 and 1970. Using a pluviographic database of the 1965-1992 period was calculated an erosivity rainfall indicator, the R factor, part of the (RUSLE) model "Revised Universal Soil Losses Equation". This factor describes the rainfall erosivity with a maximum intensity at 30 minutes. Before was carried an analysis of seasonality change in the period mentioned. As a result was evidenced an increase in the last decades of the R factor value, as well as a displacement of the dry period was detected in the decade of 1965-1980 that it goes diminishing near to 1990 years. [ABSTRACT FROM AUTHOR]

In this paper, we propose the representation of the Southern Oscillation Index (SOI) dynamics using a new class of nonlinear hybrid model. In this new model, the non-linearity in the mean is represented by an adaptive neurofuzzy inference system (ANFIS), while the variance is represented using an autoregressive conditional heterocedastic (ARCH) component. In addition, a specification strategy for the proposed model, which is based on a battery of statistical tests is developed. The results indicate that the proposed model captures in a better way the main features of the studied time series, when compared to other competitive models. [ABSTRACT FROM AUTHOR]