Updates to ESRL’s Flow-following Finite Volume Icosahedral Model (FIM)-Chem Global Modeling System and Comparison of Aerosol Optical Depth Forecasts with AErosol RObotic NETwork (AERONET) Observations
G. Grell1, S. McKeen2, S. Freitas3 and S. Sahm1
1NOAA Earth System Research Laboratory, 325 Broadway, Boulder, CO 80305; 303-497-6924, E-mail: Georg.firstname.lastname@example.org
2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309
3Brazilian National Space Institute (INPE), Center for Numerical Weather Forecast and Climate Studies (CPTEC), Cachoeira Paulista, Brazil
Development of the FIM, ESRL's new global model for medium range weather forecasting, is being extended to include new improvements for aerosols, dust, and wild fires. The FIM uniquely combines 3 key modeling design components (icosahedral horizontal grids, isentropic-hybrid vertical coordinate, finite volume numerics), all critical to provide improved transport over existing models (e.g. Global Forecast System (GFS)). The isentropic-hybrid vertical coordinate is “flow-following” in that the vertical coordinate surfaces follow isentropic (constant potential temperature) surfaces through most of the atmosphere, from mid-troposphere upward to the model top (current testing at ~60 km). Aerosol interaction with atmospheric radiation is included using the GFS physics. The aerosol indirect effect can be tested using a newly developed convective parameterization (Grell and Freitas). We will show results of evaluating a three-month retrospective period with observed aerosol optical properties from AERONET network.