Influence of soil moisture on mesoscale convective initiation in central Mexico

Abstract

The presence of deep moist convection in a large part of Mexico is a condition typical of summer; the effects of land surface processes and mesoscale circulations are usually not included in the diagnostic and forecasting of deep moist convection, mainly because of the scale at which they occur. This study examines the effect of the soil moisture fluxes on convective initiation in the central region of Mexico during the summer periods of 2010–2014. Other aspects considered are the function of the average flux of the boundary layer in the transport of humidity towards the initiation zone. Remote sensing satellite data used are the cloud-top temperature, soil moisture, land surface temperature and precipitation. The results show over the initiation zone an increase in the soil moisture and a decrease in the land surface temperature in the direction of the mean flux at low levels. The soil moisture anomaly (SMA) presents a temporal variability being May, the composite more similar to previous studies, initiation zone drier and warmer than surroundings. The background low-level winds have an important role in the displacement of convection core and creating different features of SMA and land surface temperature anomaly.

Keywords

• convective initiation
• soil moisture
• remote sensing