Extreme Precipitation Events in the Valley of Mexico as Revealed by a Long-term Climate Simulation
Abstract
Long-term changes in precipitation intensity in the valley of Mexico are evaluated through the use of convective-permitting model simulations of objectively identified severe weather events during the historical 1985-2015 period. Severe weather events are defined as days when the highest atmospheric instability and moisture occur within a 25km long-term regional climate simulation. Further dynamical downscaled simulations are performed with convective-permitting (2.5 km) grid spacing to explicitly represent thunderstorms necessary for physically confident in precipitation extremes. Results are compared to available observed precipitation data to verify that the atmospheric model can reasonably represent the statistical characteristics of local diurnal circulation patterns and precipitation within the valley of Mexico. Statistical evaluation of precipitation extremes is performed using peaks-over-threshold approach with a generalized Pareto distribution. An observed, statistically significant long-term increase in atmospheric moisture and instability causes an increase in extreme summer precipitation in the severe weather event simulations. Precipitation is becoming more intense within the context of the diurnal cycle of convection.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A13A0211L
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 3337 Global climate models;
- ATMOSPHERIC PROCESSESDE: 3355 Regional modeling;
- ATMOSPHERIC PROCESSES