STEM Model Products Data Version: Forecast_Products Data Citation: Gregory R. Carmichael, Bhupesh Adhikary, Sarika Kulkarni and Marcelo Mena Address: The Center for Global and Regional Environmental Research (CGRER), The University of Iowa, IA, 52242 Questions/Contact: Dr. Gregory Carmichael, gcarmich@engineering.uiowa.edu or Bhupesh Adhikary, badhikar@engineering.uiowa.edu Sarika Kulkarni, sarika-kulkarni@uiowa.edu Marcelo Mena, marcelo-mena@uiowa.edu Data Description: The PACific Dust Experiment (PACDEX) field campaign took place from April to May, 2007. The Center for Global & Regional Environmental Research, at the University of Iowa provided daily chemical weather forecasts in support of this experiment. The University of Iowa's STEM regional chemical transport model were performed at 50km horizontal grid resolution. The Weather Research & Forecasting (WRF) model provided meteorological fields to drive the STEM model transport. The STEM model employs simple decaying rates for most primary species, plus wet scavanging and dry depostion. We can roughly derive the AVERAGE aging time for certain species based on their decaying rates if rain and cloud are not heavy, or have low impact on these species. The presented ages can be used ONLY as a reference, due to realistic complexity. Please note that the regional CO tracer concentrations DO NOT represent the realistic concentration, but only as contribution from various sources. The NETCDF file descriptions are as follows (self explanatory within each NETCDF file). Meteorology and STEM products are based on 'STEM Native GRID' which are defined by the topography file for geographical latitude and longitude. 1)TOPO.314x200-pacific-50km.nc --> Geography related variables for each grid cell. 2)wrfheight.314x200.nc --> 3d Model layers, height of each gridcell. 3)meteo3d-118-2k7.314x200.nc --> 3d meteorology file. The time starts at Julian Day on the filename. The new file has the latest forecast at that time. Eg. for Julian Day 122, the meteo3d-122-2k7.314x200.nc has the latest meteorology forecast. 4)TROUT.04-28-00.nc --> STEM model 3d output file. Time as indicated by filename. BC1 and BC2 are hydrophobic and hydrophillic Black Carbon. Similar for OC which is Organic Carbon. Dust1 is fine mode (less than 1 micrometer) mineral dust. Dust2 is coarse mode (1 Back-trajectories of wind vectors separated by each flight. The trajectories are initiated every minute at the aircraft flight altitude. The trajectories go back 4 days. The files start Backtraj-YYYY-DDD-HHMMSS.