Chun Zhao

Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA

10am, 3 Nov, 2014

LAPC, IAP

Abstract

The WRF-Chem model was recently coupled with the community land model (CLM), which provides a new opportunity of investigating aerosol-land interaction. In this WRF-Chem-CLM modeling framework, the MEGAN model and the SNICAR model embedded in CLM can be used to simulate biogenic emissions and aerosol impact on snow, respectively. The SNICAR model includes the most sophisticated representation of snow metamorphism processes available for climate study. The MEGAN model has been widely used to simulate biogenic VOC emissions. First, I will introduce using WRF-Chem to simulate the impact of light absorbing aerosols on snow and hydrological cycle. The WRF-Chem is used to simulate the black carbon (BC) and dust concentrations and their radiative forcing in seasonal snow over Euroasia. Extensive field and satellite measurements are used to evaluate the model performance. In general, the model simulated spatial variability of BC and dust mass concentrations in the top snow layer are consistent with observations. The impact of BC and dust in the snowpack and in the atmosphere on the variability of regional hydrological cycle and temperature is characterized. Second, the WRF-Chem-CLM modeling framework is used to examine the sensitivity of simulated VOCs and ozone to land surface processes and vegetation distributions, both of which could have significant impacts on biogenic trace gases that can affect secondary organic aerosol (SOA) formation and ultimately aerosol radiative forcing. The experiments are conducted over California where the measurements collected during the Carbonaceous Aerosol and Radiative Effects Study (CARES) in June of 2010 provide a good opportunity to evaluate the simulations.