Temperature Variability over South America's Continental and Adjacent Seas: 1979–2017

The objective this work is to evaluate the temperature variability over South America continental and adjacents sea (ASSEA; 90^oW a 20^oW e 60^oS a 10^oN) distinctly, between 1979 and 2017. The analysis include the tropical/northern (TA; 90^oW-20^oW and 20^oS to 10^oN) and subtropical/southern (SSA; 90^oW to 20^oW and 60^oS to 20^oS) of the ASSEA. To compare climate change over ASSEA with global changes, the temperature variation over the entire planet, continental areas and oceans of the globe are shown too, distinctly. The subperiods 1979 to 2005 and 2006 to 2017 are also analyzed. The air temperature 2 meters above the surface from the National Centers for Environmental Prediction (NCEP)/Department of Energy (DOE) is used in this work. The average temperatures for the globe, ASSEA, AT and SA are 14.70, 19.17, 24.42 and 13.99^oC, respectively, between 1979-2017; 14.58, 19.14, 24.36 and 14.01^oC between 1979-2005 and 14.96, 19.22, 24.57 and 13.96^oC between 2006-2017. Over continental areas the average temperatures for the globe, ASSEA, AT and SA are 8.92, 21.05, 23.46, 15.65^oC between 1979-2017; 8.76, 21.05, 23.37 e 15.86^oC between 1979-2005 and 14.47, 18.77, 24.22, 13.40^oC between 2006-2017. Over sea areas of the globe, ASSEA, AT and SA the average temperatures are 16.99, 18.18, 25.32 and 13.55^oC between 1979-2017; 16.89, 18.14, 25.28, 13.51^oC between 1979-2005 and 17.20, 18.27, 25.40, 13.64^oC between 2006-2017. The global temperature variation reflects the ocean temperature variation, since ~ 71% of the global surface is covered by these. Globally, the lowest values of temperature on the continents are the result of their location in the middle and high latitudes, while most of the oceans are located in the tropical and media latitudes, as well as the different physical characteristics of these two surfaces. Considering whole planet the warming was greater on the continents than on the oceans in the period 2006-2017 comparing to the period 1979 to 2005 and the tendency of warming is more evident on the continents. There are temperature peaks on the two mediums when occurred strong El-Niño event (83, 98 and 2016), however the heating in both media is occurring independently of ENSO. On the ASSEA the temperatures are higher over the continent. In the past 3 years (2015 to 2017) temperature on the continent was above the average period (1979-2017). However, with temperatures below average prevailing in the last 18 years. On the ocean areas in the tropical region predominated temperatures below (above) the average before (after) 2000. While global warming is clear and is not associated with ENSO, for ASSEA increasing temperature is more tenuous and its variability is associated with ENSO. For the tropical area ASSEA (TA), the annual temperatures are higher in marine areas that on the continental areas. However, the variability of temperature, as the warming trend from the year 2000 is very similar for the two mediums. Over the subtropical region (SSA) the temperature on the continent is higher than on the adjacent oceans. On the continent the temperature is below average (1979-2017) from second half of the nineties. In addition, there is no warming trend on the continent and ocean in this subtropical region.

Key-Words: Climate Change; Reanalysis NCEP/DOE.