PDO-ENSO effects in the climate of Mexico

The role of the Pacific decadal oscillation (PDO) in El Nino-Southern Oscillation (ENSO)-related Mexican climate anomalies during winter and summer is investigated. The precipitation and mean temperature data of approximately 1000 stations throughout Mexico are considered. After sorting ENSO events by warm phase (El Nino) and cold phase (La Nina) and prevailing PDO phase: warm or high (HiPDO) and cold or low (LoPDO), the authors found the following: 1) For precipitation, El Nino favors wet conditions during summers of LoPDO and during winters of HiPDO. 2) For mean temperature, cooler conditions are favored during La Nina summers and during El Nino winters, regardless of the PDO phase; however, warmer conditions are favored by the HiPDO during El Nino summers.