Implementation of the Adapted Bonner Criterion to Identify Cold Weather and Precipitation in the Peruvian-Bolivian Altiplano during Winter (#1142)

Authors

Medina Burga, Melissa De Jesús

Peña Murillo, Robinson Fabricio

Calderón Cahuana, Carlos Raúl

Santos Andahua, Jorge Enrique

Fashé Raymundo, Octavio

Abstract

The study focuses on identifying the circulation patterns (CP) in the winter season that are related to the occurrence of precipitation in the Peruvian-Bolivian Altiplano and part of the Bolivian Amazon. The atmospheric circulation patterns determined by Medina (2020) for the austral winter were used, the 7 CPs were found, and various statistical methods such as ascending hierarchical classification and SOM neural networks were used. These patterns were determined at an atmospheric level of 200 hPa, wind data from ERA - Interim, corresponding to 1976 - 2016, and the precipitation of 173 meteorological stations located in the region of 15º S - 25º S, 80º W - 60º W was related to each pattern. In addition, longwave radiation (OLR) data from NCAR / NOAA with a resolution of 2.5 were used. ° x 2.5° from 1979 to 2016. The precipitation behavior associated with the identified patterns describes well-defined temporal cycles. These behaviors are linked to meteorological events, such as segregated lows, for which the modified Bonner criterion was used and defined at the El Zongo glacier (16º 12' 0" S and 68º 6' 0" W). The results were compared with data from the SENAMHI and OLR stations, arguing that one of the mechanisms associated with the probability of precipitation is DANA at high levels and incursions of directed winds at low levels.