World Environmental Conservancy

When It Rains in the Largest Desert on Earth

Atmospheric rivers and moisture transport to Antarctica

Last year, a report by Deutsche Welle highlighted unusual events of moisture transport reaching Antarctica. These episodes are associated with intense atmospheric flows of water v***r known in the scientific literature as Atmospheric Rivers—narrow corridors of concentrated moisture that can transport large amounts of water v***r from the tropics and mid-latitudes toward polar regions.

Under certain atmospheric conditions, these moisture plumes can pe*****te deep into the Antarctic continent, particularly affecting West Antarctica. When this occurs, the transported moisture may result in precipitation events. Traditionally, precipitation over Antarctica falls almost exclusively as snow. However, recent observations indicate that some of these events have produced rain, a phenomenon that remains relatively rare across most of the continent.

Despite its extensive ice cover, Antarctica is often classified as the largest desert on Earth in terms of annual precipitation. On average, the continent receives approximately 160 mm of precipitation per year, with even lower values recorded in the interior plateau. In addition, Antarctic air masses are characterized by extremely low humidity, creating a predominantly cold and dry atmospheric environment.

The occurrence of rainfall in such a setting has raised concerns among scientists. Liquid precipitation can accelerate surface melting, promote the infiltration of water into existing fractures within ice shelves, and contribute to structural weakening through processes such as hydrofracturing. When meltwater accumulates or pe*****tes crevasses, it can increase stress within the ice, potentially leading to ice-shelf destabilization and enhanced ice discharge into the surrounding ocean.

Another important factor is the relatively rapid warming observed in the Antarctic Peninsula. Over the past decades, this region has experienced some of the highest rates of temperature increase on the planet. Warmer conditions increase the likelihood that precipitation associated with atmospheric rivers will fall as rain rather than snow, particularly during episodes of strong heat and moisture advection from lower latitudes.

Taken together, these observations suggest a possible intensification of meridional heat and moisture transport toward Antarctica. If such trends continue, they may have important implications for the stability of Antarctic ice shelves, the mass balance of glaciers, and ultimately the global climate system and sea-level rise.

The full article can be accessed on the page: www.worldenvironmentalconservancy.org

WEC congratulates researchers Heber Passos/INPE, Franco Vilella/INMET and Heitor Evangelista/UERJ (photo), for the excellent work developed on the Antarctic continent. A source of pride for Brazilian science, the Cryosphere1 Project has been standing out for its cutting-edge research carried out in Brazil's first research module to operate autonomously and remotely in Central Antarctica.

It is with immense sorrow that the World Environmental Conservancy announces the passing of the first Brazilian to set foot in Antarctica.
Professor Rubens Junqueira Villela, a retired meteorology professor from USP (University of São Paulo), passed away today, January 21, 2026, at the age of 95.
A graduate of Florida State University (1957), he was a great enthusiast of Antarctic expeditions.
He was the first Brazilian to set foot on the geographic South Pole, where he traveled at the invitation of the USA polar research service in 1961. After that, he made 10 more expeditions to the continent at the invitation of the Brazilian Antarctic Program.
He worked as a meteorologist at Panair of Brazil, BBC London, Aero Magazine, Weather Channel, among other companies.
He left a huge legacy of knowledge in operational, polar, and aeronautical meteorology.
Today, his son, Franco Villela, follows in his father's footsteps and already has several expeditions to Antarctica on his resume.