Assessing the role of land surface hydrology model initializations in the simulation and prediction of North American Monsoon precipitation character
Abstract
Land surface hydrology has been implicated as an active participant in the initiation of atmospheric convection under certain conditions. What is less clear is how terrestrial hydrologic variability, superimposed on complex terrain regions, modifies background circulation structures such as mountain valley and mountain plain flows. Additionally, there is considerable uncertainty as to how selection of land surface model spin-up decisions, influence the simulation and prediction of important precipitation characteristics such as occurrence, intensity and spatial extent. This study examines, in detail how decisions in the model spin-up process, such as selection of physics, land surface parameters and offline forcing data affect simulation and prediction quality. The Advanced Weather Research and Forecasting Model (WRF-ARW) was applied at a 4km grid spacing in seasonal simulation and prediction modes for the summer of 2004. We present the results in the context of assessing the influence of land surface hydrologic forcing versus various possible states of atmospheric conditions including a priori moisture availability and stability. Model results are validated using hydro-meteorological data collected as part of the 2004 North American Monsoon Experiment. Emphasis of the analyses is placed on diagnosing key variables and threshold values for the initiation and growth of convective cloud cover and precipitation in the mountainous and coastal plain regions of northwest Mexico. We conclude the presentation with a set of recommendations for future observational activities which may have the potential to reduce model initialization errors and improve forecast skill.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2013
- Bibcode:
- 2013AGUSM.U54A..04G
- Keywords:
-
- 1833 HYDROLOGY / Hydroclimatology;
- 1843 HYDROLOGY / Land/atmosphere interactions;
- 1854 HYDROLOGY / Precipitation