Circulaciones atmosféricas en el Ecuador y su influencia sobre la ciudad de Quito

Abstract

In this research are analyze and identifies atmospheric circulation patterns, synoptic scale systems over Ecuador and their affectation to Metropolitan District of Quito (MDQ) organizing in quarterly, dry and rainy periods, to the daily series of air temperature, relative humidity, atmospheric pressure, zonal component, meridional component of the wind and precipitation at the isobaric levels of 700, 500 and 200hPa. Then daily vertical profiles of humidity, air temperature, wind and precipitation were made over the MDQ, finally using wavelets were elaborated spectra for series of daily data of surface precipitation, zonal wind and meridional wind, organized quarterly, to establish the presence of synoptic scale signals in the sector.

The results evidenced that general circulation of the atmosphere over Ecuador, they influence over MDQ to following way: the predominant winds in 700hPa are from the NE. While than in 500hPa the predominant winds during all year are from the NE and E. Finally in 200hPa the dominant winds are from the NE and E, with the exception of the Dec-Ene-Feb period in witch predominant winds are from the SE and E. It was checked that the precipitation over the MDQ responds to the annual migration of the ITCZ.

With the analysis of the daily vertical profiles was evidenced to passage of undulations in the wind that regulate the fluctuations of the other variables. The change in the meridional component of the wind marks the passage of these systems, as well as the behavior of humidity and precipitation, defining that the winds in 200 and 250 hPa regulate the dry and humid conditions over the MDQ.

The spectral analysis evidenced signals of systems in synoptic scale with slight spectral fluctuations with the threshold of 3 to 5 days over the MDQ, these systems are more intense in: the precipitation, especially in the rain periods and in the meridional component of the wind in dry and rainy periods.