Analysis of atmospheric and oceanographic systems of the Aegean Sea with long-term data

In this study, temporal and spatial trends of sea surface temperature (SST), air temperature, wind speed and direction, sea surface salinity, sea level pressure (SLP) and upwelling indexes are examined and compared with previous studies. Analyses of parameters are performed for five critical locations, which illustrate the best characteristic of meteorological and oceanographic structures of the Aegean Sea. The response & effect of climate change on the Aegean Sea are investigated by using long term ECMWF ERA-Interim data, which covers the years from 1979 to 2018; moreover Copernicus (Global SSS/SSD L4) is used for obtaining surface salinity data that cover the period of 2000-2015. Linear trend and Mann Kendall tests are applied to find out the tendency and long-term variations. According to ECMWF Reanalysis data over the past 40 years, monthly average SST (+0.017 and + 0.046°C/yr) and air temperature (+0.017 and +0.030 °C/yr) have a rising trend. As a result of the validation, there is a decreasing trend in wind speed (-0.0016 and -0.007 kts/yr) and surface atmospheric pressure (-0.032 and -0.027 mb/yr) in the Aegean Sea. When previous studies are compared with the results obtained in this study, despite of different values it is seen that they are compatible with eachother. It is hard to determine, however, whether these changes are related to the world's nature response. In order to easily detect upwelling, effectiveness of different upwelling index calculations used for oceans was tested by appliying on the Aegean Sea and compared with eachother. The results show that SST and wind driven upwelling indexes could be roughly used in the detection of upwelling in the Aegean Sea but it is not sufficient for the precise determination of upwelling.