README -- Describes contents of HEMCO/OFFLINE_DUST/v2020-05 directory 15 Apr 2020 updated on 23 April 2021 Jun Meng Overview: ============================================================================== Grid-independent offline dust emissions are now available for GEOS-Chem at native MERRA-2 (0.5° x 0.625°) and GEOS-FP (0.25° x 0.3125°) meteorology field resolution. Instructions to calculate the offline emissions can be found on the GEOS-Chem wiki: http://wiki.seas.harvard.edu/geos-chem/index.php/Mineral_dust_aerosols#Offline_Dust_Emissions. Developed by David Ridley (david.ridley@arb.ca.gov); Processed, updated, and evaluated by Jun Meng (jun.meng@dal.ca) Reference: Meng, J., Martin, R. V., Ginoux, P., Hammer, M., Sulprizio, M. P., Ridley, D. A., van Donkelaar, A., Grid-independent High-Resolution Dust Emissions (v1.0) for Chemical Transport Models: Application to GEOS-Chem (version 12.5.0). Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2020-380, in review, 2020. ------------------------------------------------------------------------- Note: This version applied a new source function with a finer resolution (0.25x0.25) from Paul Ginoux. Scale factors should be included in "HEMCO_Config.rc" to make the total annnual dust emission to 2000 Tg: GEOS-FP: 5.7141e-04 (North America dust source optimizing (reducing 30% emission) by applying scale factor 666, which includes a mask file of "DustEmis_scalefactor_NA_optimized.nc". See the example "HEMCO_Config_w_NA_optimizing.rc") MERRA2: 4.7376e-04 (North America dust source optimizing (reducing 30% emission) by applying scale factor 666, which includes a mask file of "DustEmis_scalefactor_NA_optimized.nc". See the example "HEMCO_Config_w_NA_optimizing.rc") ------------------------------------------------------------------------- Files: =============================================================================== 0.25x0.3125/YYYY/MM/dust_emissions_025.YYYYMMDD.nc Resolution : 0.25 x 0.3125 grid (721 x 1152 boxes) Units : kg m-2 s-1 Timestamps : Hourly, 2014 thru present Compression : Level 1 (nccopy -d1) Chunking : nccopy -c lon/1152,lat/721,time/1 0.5x0.625/YYYY/MM/dust_emissions_05.YYYYMMDD.nc Resolution : 0.5 x 0.625 grid (361 x 576 boxes) Units : kg m-2 s-1 Timestamps : Hourly, 1980 thru present Compression : Level 1 (nccopy -d1) Chunking : nccopy -c lon/576,lat/361,time/1