Variability of Extreme Precipitation Events in Tijuana, Mexico During ENSO Years

HR: 09:00h
AN: PP51A-04 INVITED [Abstracts]
TI: Variability of Extreme Precipitation Events in Tijuana, Mexico During ENSO Years
AU: * Cavazos, T
EM: tcavazos@cicese.mx
AF: Dept. de Oceanografia Fisica, CICESE, Mexico, Carr. Tijuana-Ensenada Km. 107, Ensenada, BC , Mexico
AU: Rivas, D
EM: drivas@cicese.mx
AF: Dept. de Oceanografia Fisica, CICESE, Mexico, Carr. Tijuana-Ensenada Km. 107, Ensenada, BC , Mexico
AB: We present the variability of daily precipitation extremes (top 10 percecnt) in Tijuana, Mexico during 1950-2000. Interannual rainfall variability is significantly modulated by El Nino/Southern Oscillation. The interannual precipitation variability exhibits a large change with a relatively wet period and more variability during 1976- 2000. The wettest years and the largest frequency of daily extremes occurred after 1976-1977, with 6 out of 8 wet years characterized by El Nino episodes and 2 by neutral conditions. However, more than half of the daily extremes during 1950-2000 occurred in non-ENSO years, evidencing that neutral conditions also contribute significantly to extreme climatic variability in the region. Extreme events that occur in neutral (strong El Nino) conditions are associated with a pineapple express and a neutral PNA (negative TNH) teleconnection pattern that links an anomalous tropical convective forcing west (east) of the date line with a strong subtropical jet over the study area. At regional scale, both types of extremes are characterized by a trough in the subtropical jet over California/Baja California, which is further intensified by thermal interaction with an anomalous warm California Current off Baja California, low-level moisture advection from the subtropical warm sea-surface region, intense convective activity over the study area and extreme rainfall from southern California to Baja California.
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4522 ENSO (4922)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Joint Assembly