README ¨C Describes contents of HEMCO/OFFLINE_SOILNOX/v2021-12 directory 
18 Feb 2022
Hongjian Weng

Overview:
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Grid-independent offline soil NOx emission is available for GEOS-Chem at native MERRA-2 (0.5 x 0.625) and GEOS-FP (0.25 x 0.3125) meteorology field resolution. These emissions were generated with GEOS-Chem 13.2.0.

The updates include:

1. The files in this directory were generated using new version Yuan-processed MODIS LAI (in Yuan_XLAI/v2021-06), as opposed to files in OFFLINE_SOILNOX/v2019-01 which used the older Yuan-LAI product (in Yuan_XLAI/v2019-03). 

For more information about updated Yuan-LAI:

https://github.com/geoschem/geos-chem/issues/717

Especially, due to lack of year-specific LAI data in older Yuan-LAI product,, we used the Yuan-LAI in 2005 for 2000-2004 soil NOx emissions and 2016 for years after 2016 in OFFLINE_SOILNOX/v2019-01. Now, these years emissions use year-specific Yuan-LAI data.

2. Fix the unit bug in OFFLINE_SOILNOX/v2019-01

For more information about the bug see:

https://github.com/geoschem/geos-chem/issues/765

3. The fluxes in HEMCO are now in kg species/m2/s throughout. The unit of new version soil NOx emission is kg/m2/s, as opposed to kgN/m2/s in OFFLINE_SOILNOX/v2019-01.

Developed by Jintai Lin (linjt@pku.edy.cn);
Processed by Hongjian Weng (wenghj@pku.edu.cn)

Files:
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0.25x0.3125/YYYY/MM/soilnox_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/soilnox_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