Variability of thermohaline regime of see water of the Gulf of Mexico in 2005-2017

The Gulf of Mexico is a large, productive, marine and coastal ecosystem providing the coastal residents and neighbouring regions with goods and services. The Gulf of Mexico's water area plays a significant role in shaping the climate across the coastal zone and the thermal state of the region's water also has a major impact on development of atmospheric processes over the Atlantic and Europe. Long-term climate variability throughout the Gulf of Mexico may affect both the strength of the Gulf Stream and heat transfer patterns within the ocean and the economic activity and environmental stability of the entire Northwest Atlantic Region. This work aims at determining the characteristics of variability of temperature regime and salinity of the Gulf of Mexico over recent decades. The study was conducted based on the Gulf of Mexico Regional Climatology (GOM RC) data, version 2, available at the website of the NOAA's National Centers for Environmental Information (NCEI). It analyzes the temperature and salinity values at different depths for the period of 2005-2017. According to the analysis, over 2005-2017 the spatial distribution of the average annual water temperature on the Gulf of Mexico's surface demonstrates its decrease from south to north. Its highest value is observed next to the northwestern coast of Cuba and along the coastal area of the Bay of Campeche, and the lowest temperature is observed at Apalachee Bay located in the northeastern part of the Gulf of Mexico. Though significant horizontal temperature gradients are observed in winter, during the warm period the temperature field is more homogeneous. The minimum average monthly water temperature on the surface is observed in January, the maximum one – in September. The most distinct seasonal changes in temperature are observed in the water of the northern part of the Gulf of Mexico next to the United States' coast. The distribution of average annual salinity of the most of the Gulf of Mexico is homogeneous with the exception of its northern part, especially in the area where the Mississippi River water flows into it, where salinity decreases sharply. Graphs of water temperature and salinity distribution at different depths across different areas of the gulf were constructed in order to determine the water stratification.