Distribution of batoid demersal assemblages on the continental shelf of the Gulf of Tehuantepec

2019 ◽  
Vol 70 (10) ◽  
pp. 1445 ◽  
Author(s):  
Ana María Torres-Huerta ◽  
Ramón Andrés López-Pérez ◽  
Margarito Tapia-García ◽  
Adolfo Gracía

Information on the relationship between batoid demersal assemblages and environmental factors is scarce. We captured a total of 23414 batoids belonging to 16 species with bottom trawls at 243 sampling stations in the Gulf of Tehuantepec, Mexico. The species Urotrygon rogersi, Urotrygon chilensis and Narcine vermiculatus represented 70.1% of the abundance and 46.3% of the biomass. Five batoid assemblages were identified using hierarchical cluster and similarity profile analyses. Four assemblages were located at depths less than 40m and one assemblage was located at depths between 40 and 62m. The main batoid group was located in front of the most important lagoon complexes. The abundance biomass comparison method indicated that small species were dominant in terms of abundance in most assemblages. The set of environmental conditions and habitat characteristics (longitude, depth and sea surface temperature) present in the Gulf of Tehuantepec predicted important changes in the batoid community and affected its spatiotemporal distribution pattern.

Ciencia Unemi ◽  
2017 ◽  
Vol 10 (22) ◽  
pp. 81-87
Author(s):  
Jhony Real CotTo ◽  
William Sánchez Calle ◽  
Fausto Hington Chica ◽  
Janeth Hurtado Astudillo ◽  
Juan Fariño Cortez ◽  
...  

En Guayaquil existe el dengue y tiene una población expuesta de forma endémico – epidémica, pero hay escasos estudios sobre la tendencia histórica de los factores que influyen en el comportamiento del dengue. El objetivo de este trabajo es relacionar los factores ambientales y el cambio climático en el comportamiento del Dengue en la ciudad de Guayaquil, durante el período 2010-2014. Se aplicó una investigación no experimental, tipo longitudinal de tendencia. Analizándose el comportamiento de dengue con la pluviosidad, temperatura, humedad y vientos por semanas epidemiológicas. Los resultados de más casos fueron en los años 2010, 2012 y 2014; existiendo variabilidad en su comportamiento. Las variables ambientales mostraron que la pluviosidad tiene escasa relación en la presencia de casos, hallazgos de humedad por encima del 70% con temperatura altas y escasos vientos provocan condiciones para incremento en la transmisión de la enfermedad, pero existen períodos epidemiológicos donde su transmisión disminuye y puede estar relacionado a las temperaturas promedios bajas, humedad relativa y presencia de vientos. A su vez, es de relevancia observar la relación que tiene el aumento de la temperatura superficial del mar con el incremento de casos de Dengue como se observa en los años de más casos.In Guayaquil there is dengue and it has an exposed population in an endemic – epidemic way, but there is little research on the historical trend of the factors that influence the behavior of dengue. The objective of this work is to relate environmental factors and climate change in the behavior of Dengue in Guayaquil city during the period 2010-2014. A Non - experimental research of a longitudinal type of trend was applied, analyzing the behavior of dengue with rainfall, temperature, humidity and winds per epidemiological weeks. The results with more cases were in the years 2010, 2012 and 2014; Showing variability in their behavior. The environmental variables showed that the rainfall has little relation in the presence of cases, humidity findings above 70% with high temperatures and few winds cause conditions to increase the transmission of the disease, but there are epidemiological periods where the transmission decreases and may be related to low average temperatures, relative humidity and presence of winds. At the same time, it is relevant to observe the relationship between the increase in sea surface temperature and the increase in Dengue cases as observed in the years of more cases


2015 ◽  
Vol 28 (8) ◽  
pp. 2945-2967 ◽  
Author(s):  
Timothy A. Myers ◽  
Joel R. Norris

Abstract Climate models’ simulation of clouds over the eastern subtropical oceans contributes to large uncertainties in projected cloud feedback to global warming. Here, interannual relationships of cloud radiative effect and cloud fraction to meteorological variables are examined in observations and in models participating in phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5, respectively). In observations, cooler sea surface temperature, a stronger estimated temperature inversion, and colder horizontal surface temperature advection are each associated with larger low-level cloud fraction and increased reflected shortwave radiation. A moister free troposphere and weaker subsidence are each associated with larger mid- and high-level cloud fraction and offsetting components of shortwave and longwave cloud radiative effect. It is found that a larger percentage of CMIP5 than CMIP3 models simulate the wrong sign or magnitude of the relationship of shortwave cloud radiative effect to sea surface temperature and estimated inversion strength. Furthermore, most models fail to produce the sign of the relationship between shortwave cloud radiative effect and temperature advection. These deficiencies are mostly, but not exclusively, attributable to errors in the relationship between low-level cloud fraction and meteorology. Poor model performance also arises due to errors in the response of mid- and high-level cloud fraction to variations in meteorology. Models exhibiting relationships closest to observations tend to project less solar reflection by clouds in the late twenty-first century and have higher climate sensitivities than poorer-performing models. Nevertheless, the intermodel spread of climate sensitivity is large even among these realistic models.


2013 ◽  
Vol 141 (3) ◽  
pp. 1118-1123 ◽  
Author(s):  
Arun Kumar ◽  
Li Zhang ◽  
Wanqiu Wang

Abstract The focus of this investigation is how the relationship at intraseasonal time scales between sea surface temperature and precipitation (SST–P) varies among different reanalyses. The motivation for this work was spurred by a recent report that documented that the SST–P relationship in Climate Forecast System Reanalysis (CFSR) was much closer to that in the observation than it was for the older generation of reanalyses [i.e., NCEP–NCAR reanalysis (R1) and NCEP–Department of Energy (DOE) reanalysis (R2)]. Further, the reason was attributed either to the fact that the CFSR is a partially coupled reanalysis, while R1 and R2 are atmospheric-alone reanalyses, or that R1 and R2 use the observed weekly-averaged SST. The authors repeated the comparison of the SST–P relationship among R1, R2, and CFSR, as well as two recent generations of atmosphere-alone reanalyses, the Modern-Era Retrospective Analysis for Research and Applications (MERRA) and the ECMWF Re-Analysis Interim (ERA-Interim). The results clearly demonstrate that the differences in the SST–P relationship at intraseasonal time scales across different reanalyses are not due to whether the reanalysis system is coupled or atmosphere alone, but are due to the specification of different SSTs. The SST–P relationship in different reanalyses, when computed against a single SST for the benchmark, demonstrates a relationship that is common across all of the reanalyses and observations.


1999 ◽  
Vol 56 (6) ◽  
pp. 973-983 ◽  
Author(s):  
Masayuki Noto ◽  
Ichiro Yasuda

The relationship between the population size of the Japanese sardine, Sardinops melanostictus, and sea surface temperature (SST) from 1979 to 1994 was studied. Significant positive correlations were found between the natural mortality coefficient during the period from the postlarval stage to age 1 and winter-spring SST in the Kuroshio Extension and its southern recirculation area (30-35°N, 145-180°E). That is, higher (lower) SST over the possible migration route corresponded to higher (lower) mortality rate. This result is consistent with the high mortality and low population size for the high-SST period of the 1950's and 1960's and the population increase during the low-SST period of the 1970's and 1980's due to a decrease in mortality. The population decline after 1988 possibly occurred as a result of the abrupt increase in SST since 1988 in the Kuroshio Extension region and suggests a close relationship between interdecadal climate-ocean variability and sardine population size. This may also explain the relationship between biomass size and distribution area.


2010 ◽  
Vol 5 (5) ◽  
pp. 367-378 ◽  
Author(s):  
Jaeil Cho ◽  
Pat J.-F. Yeh ◽  
Yang-Won Lee ◽  
Hyungjun Kim ◽  
Taikan Oki ◽  
...  

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