| Full text | |
| Author(s): |
Gutierrez-Villarreal, Ricardo A.
;
Espinoza, Jhan-Carlo
;
Lavado-Casimiro, Waldo
;
Junquas, Clementine
;
Molina-Carpio, Jorge
;
Condom, Thomas
;
Marengo, Jose A.
Total Authors: 7
|
| Document type: | Journal article |
| Source: | WEATHER AND CLIMATE EXTREMES; v. 45, p. 13-pg., 2024-08-07. |
| Abstract | |
The 2022-23 hydrological year in the Lake Titicaca, Desaguadero River, and Lake Poopo<acute accent> hydrological system (TDPS) over the South American Altiplano constituted a historically dry period. This drought was particularly severe during the pre-wet season (October-December), when the TDPS and the adjacent Andean-Amazon region experienced as much as 60% reductions in rainfall. Consequently, Titicaca Lake water levels decreased by 0.05 m from December to January, which is part of the rising lake level period of normal conditions. Such conditions have not been seen since the El Nino-related o-related drought of 1982-83. Using a set of hydroclimatic, Sea Surface Temperature (SST) and atmospheric reanalysis datasets, we find that this new historical drought was associated with enhanced southerly moisture flux anomalies, reducing the inflow of moisture-laden winds from the Amazon basin to the TDPS. Such anomalies in moisture transport were not seen since at least the 1950s. The atmospheric dynamics associated with this drought are related to La Nina a SST anomalies via subtropical teleconnections associated with Rossby wave trains towards South America, further extended by subtropical Atlantic Ocean SST anomalies. This feature reduced the atmospheric moisture inflow from the Amazon and weakened the development of the Bolivian High in the upper troposphere. These results document a new atmospheric mechanism related to extreme droughts in the TDPS associated with La Nina a SST anomalies during the pre-wet season. This goes beyond the traditional understanding of El Nino o events, especially the strongest ones, being associated with dry conditions in the TDPS during the wet season (December-March). (AU) | |
| FAPESP's process: | 14/50848-9 - INCT 2014: INCT for Climate Change |
| Grantee: | Jose Antonio Marengo Orsini |
| Support Opportunities: | Research Program on Global Climate Change - Thematic Grants |