The role of La Nina
La Niña, the backlash of El Niño, peaks around the turn of the year and is strangely underestimated. During La Niña, strong easterly winds on the west coast of South America bring cold deep water back to the surface and push the warm water to Southeast Asia, where it rains more than usual very high level. The consequences of La Niña differ depending on the strength and severity of the phenomenon, they can be felt directly on the Pacific, but also in all other regions of the world in the tropics and subtropics. Climate researchers call these long-distance effects teleconnections. East Africa in particular suffers from strong La Niña events with drought, but also the south of South America.
In any case, Argentina’s national weather service sees a connection between La Niña and the heat wave. “La Nina is here. For the second year in a row, we are feeling the consequences of the weather phenomenon,” said the national weather service, announcing that the phenomenon has a probability of more than 80 percent to last throughout the summer. Climate researcher Erich Fischer sees the connection with Enso for the months of January and February as speculative and low and refers to the studies by Matilde Rusticucci, who found little evidence for this hypothesis. Overall, La Niña appears to result in slightly hotter days in the region than El Niño, but the Pacific weather phenomenon is not the only factor. On the other hand, it is very likely that the persistent drought in large parts of the country over the past three months made a significant contribution to the high temperatures. In Buenos Aires, for example, there was significantly less rain than the long-term average.
The consequences of this extreme scenario are only likely to become apparent in the next few days. Doctors and climate researchers expect numerous heat deaths and possible excess mortality, as in previous heat waves in Argentina. In addition, the authorities expect drinking water bottlenecks, power outages and vegetation fires. Fires only raged in some provinces in December 2021, and there is a strict fire ban in the national parks. The situation is made more difficult by the fact that the Rio Paraná, the second largest river on the continent and the most important trade route, has been carrying less water for several months than it has in 80 years.
The effects of heat and drought on agriculture can currently only be estimated. Farmers are expecting the worst, the ongoing drought is taking its toll on the Pampa, the country’s largest breadbasket. Agricultural researchers expect high losses, especially for corn and soybeans, if rain does not set in soon. After all, a change in the weather is in sight, the meteorologists are already expecting heavy rain and thunderstorms on Saturday evening, and it will cool down significantly at the beginning of the week. The great heat will then be over for the time being.