Atmospheric circulation patterns associated with surface air temperature variability trends between the Antarctic Peninsula and South America.

This study investigated the spatial patterns of atmospheric circulation associated with surface air temperature variability trends between the Antarctic Peninsula and South America, during the austral summer (1979-2020). The first mode shows a positive score trend, with warming in northern Antarctic Peninsula and southern South America. This mode is mainly associated with the positive/neutral Southern Annular Mode and La Niña phases.

Oceanic SACZ produces an abnormally wet 2021/2022 rainy season in South America.

The oceanic South Atlantic Convergence Zone (SACZ) has played a major role during South America's 2021/2022 summer extreme rainy season, being responsible for more than 90% of the precipitation in some regions of Southeast Brazil and in some regions of the Southwestern Atlantic Ocean (SWA). The summer of 2021/2022 was unique and rare and considered an abnormally humid season as verified by official Brazilian Institutes. First, the unusual number of cases of SACZ episodes (seven), was the highest recorded in the last decade.

Sensitivity of South America Climate to Positive Extremes of Antarctic Sea Ice.

Global climate change is expected to increasingly affect climate-sensitive sectors of society, such as the economy and environment, with significant impacts on water, energy, agriculture and fisheries. This is the case in South America, whose economy is highly dependent on the agricultural sector. Here, we analyzed the sensitivity of South American climate to positive extremes of Antarctic sea ice (ASI) extent and volume at continental and regional scales.

Lagged response of Tropical Atlantic Ocean to cold and fresh water pulse from Antarctic sea ice melting.

The formation of dense water masses at polar regions has been largely influenced by climate changes arising from global warming. In this context, based on ensemble simulations with a coupled model we evaluate the meridional shift of a climate signal (i.e.

Combined performance of September's Weddell sea ice extent, Southern Annular Mode, and Atlantic SST anomalies over the South American temperature and precipitation.

This paper aims to analyze the relationships among tropical (Atlantic Meridional Mode - AMM), subtropical (South Atlantic Subtropical Gradient - SASG), and extratropical (Southern Annular Mode - SAM) teleconnection patterns, the Weddell Sea (WS) sea ice extents, and the climate in South America. Warm anomalies are observed in most of South America for maximum WS ice extent combinations (negative SAM/positive AMM and negative SAM/positive SASG composites), with an opposite signal at tropical South America for minimum WS ice extent combinations (positive SAM/negative AMM and positive SAM/negative SASG). Over Southern Argentina, colder (warmer) temperatures are seen at the negative SAM/positive SASG (positive SAM/negative SASG).

Response of southern troposphere meridional circulation to historical maxima of Antarctic sea ice.

The variability of Antarctic sea ice (ASI) has great potential to affect atmospheric circulation, with impacts that can extend from the surface to the middle and high levels of troposphere. The present study has evaluated the response of South Atlantic tropospheric circulation to increased coverage in area and volume of ASI. Monthly data of air temperature, zonal and meridional wind and mean sea level pressure were obtained from two ensemble simulations performed with the GDFL/CM2.

Oceanic eddy-induced modifications to air-sea heat and CO fluxes in the Brazil-Malvinas Confluence.

Sea surface temperature (SST) anomalies caused by a warm core eddy (WCE) in the Southwestern Atlantic Ocean (SWA) rendered a crucial influence on modifying the marine atmospheric boundary layer (MABL). During the first cruise to support the Antarctic Modeling and Observation System (ATMOS) project, a WCE that was shed from the Brazil Current was sampled. Apart from traditional meteorological measurements, we used the Eddy Covariance method to directly measure the ocean-atmosphere sensible heat, latent heat, momentum, and carbon dioxide (CO) fluxes.