Fog Modeling in the Mexico City's International Airport Region

Fog is a phenomenon that has an important role in the hydrological cycle, particularly in the transport of water from the atmosphere to surface of the Earth through wet deposition and interception by vegetation. Also, fog is a danger to land, sea and air navigation due to the low visibility it produces. In particular, airport operations may be hindered and even prevented by the presence of such phenomenon. Such is the case of Mexico City's International Airport (AICM), the most important in the country in terms of its number of operations, where the occurrences of fog events lead to significant safety problems and economic costs.

In order to have a better understanding of the processes involved in the formation and development of the phenomenon, a characterization of fog events was carried out in the AICM region for the ten-year period between 2003 and 2012. Individual events were characterized as to what types are the most common in the region (radiation, advection and frontal) according to their mechanism of formation. Surface, radiosonde and reanalysis data were used to determine weather conditions previous to fog formation and for its duration and dissipation stages, this resulting in a fog climatology for the Mexico City Basin.

With the results of study mentioned above, the Weather Research & Forecasting (WRF) model was used to verify its skills as a diagnostic tool for the occurrence of fog events in the Mexico Basin. Various parameterizations for land use, planetary boundary layer and microphysical processes were tested to determine which configuration of the model best reproduces the features for each type of fog and over different seasons. A discussion about the relevant cloud microphysical mechanisms is also presented. It is expected that these results will be useful for improving fog forecasting in the region of interest.