HR: 08:30h
AN: H31E-02 INVITED     [Abstracts]
TI: Understanding the Rainfall Daily Climatology of Northwestern Mexico
AU: * Brito-Castillo, L
EM: lbrito04@cibnor.mx
AF: Centro de Investigaciones Biologicas del Noroeste SC, Km 2.35 Camino al Tular, Estero de Bacochibampo, Guaymas, Son 85454, Mexico
AB: Maximum monthly precipitation (MMP) over northwestern Mexico is not concurrent because it occurs in different months from July through September. However, instead of occurring progressively from one month to the next as latitude increases, as it might be logic since rains move progressively from south to north as monsoon develops, MMP occurs in July in latitudes of Jalisco state, then MMP shifts to August more to the north in latitudes of Nayarit state and along the eastern coast of the Gulf of California, then it occurs in July in higher latitudes through the main axis of the Sierra Madre Occidental (SMO), and finally MMP shifts to September to the west in the California Peninsula. The maximum monthly streamflow occurs in a similar pattern as MMP does but one month later. When daily rainfall climatology of the region is calculated, i.e. the long-term mean per day from stations with more than 20 years of data between 1940 and 2004, it is possible to understand why the behavior of MMP occurs in a July-August-July pattern from south to north. Preliminary results indicate that at latitudes of Nayarit state normal frequent storms with abundant rains develop at the end of July and through the August. These rains sum to the rains that move from the south to the north, as monsoon develops increasing the volume of precipitations at those latitudes in August. To the east crossing the SMO through northwestern Zacatecas state maximum volume of precipitations also is observed in August. However, in higher latitudes it is not observed any increment of rains in August and consequently maximum volume of precipitations occurs in July. To understand the dynamics of the rains at the latitudes of Nayarit state it results necessary to investigate the source of these local rains and explain why the increase of precipitations in August is limited at those latitudes.
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
DE: 3354 Precipitation (1854)
SC: Hydrology [H]
MN: 2007 Joint Assembly