The regional water cycle and surface energy balances with the NOAH LSM in the the provinces of Cuyo región.

MARIO N. NUÑEZ; ALFREDO ROLLA; ERNESTO H. BERBERY

Mendoza

Congreso; XI Congreso Argentino de Meteorología; 2012

Centro Argentino de Meteorólogos

The water cycle is a key component of the Climate System, and the quality of its representation is intimately linked to the adequate simulation of seasonal and interannual climate variability. For this reason it is important in climate change studies and scenarios, and consequently it can also be used to evaluate a model’s performance. The Cuyo region is in the central west part in Argentina. Not many estimates of the Cuyo water cycle and energy balance have been presented in the literature. Of particular interest is the study of the hydrological cycle components and its extremes. The surface energy balance is closely related to the water cycle and is an integral part of the interactions between the atmosphere and land surface (soil, vegetation, snowpack). In its most basic form and dismissing some minor magnitude terms, the surface energy responds to a simple balance between the net radiation energy gained at (evapotranspiration) heat fluxes. Soil moisture is known to have a strong control on the partition between the sensible and latent heat fluxes, known as the Bowen ratio. In addition, the link between surface states and the atmospheric hydrologic cycle intrinsically involves the atmospheric boundary layer. The High Resolution Land Data Assimilation System (HRLDAS) runs the Noah Land Surface Model (Noah LSM) in an uncoupled mode (i.e., not coupled with any atmospheric model) to evolve land surface and soil state variables over some time period. The time period for which the Noah LSM was run is 26 years. From initial conditions of soil temperature, soil moisture, and other state variables, HRLDAS applies the Noah LSM, forced by analyses of atmospheric conditions, shortwave and long wave radiation, and precipitation, to update the land state. We performed numerical experiments using the HRLDS (High Resolution Land Data Assimilation System) 3.2 model in an uncoupled version. The regional water cycle and surface energy processes of Cuyo as estimated from numerical experiments using the HRLDAS 3.2 model were discussed in this paper. The terrestrial water cycle and all energy related computations were analyzed here using a 26-year long (1980 to 2006) data set for the Cuyo region.