FlexAOD
FlexAOD (Flexible Aerosol Optical Depth) is a post-processing tool of GEOS-Chem, aimed at extending the model on-line capabilities concerning calculations of Aerosol optical properties.
THIS PAGE IS STILL UNDER CONTRUCTION! PLEASE COME BACK LATER!
User's Guide
Download code & data
Source code, input & test data are at this link: http://pumpkin.aquila.infn.it/flexaod/download
From a Linux/Unix terminal, you may follow this procedure:
mkdir -p geos-chem/flexaod cd geos-chem/flexaod wget http://pumpkin.aquila.infn.it/flexaod/download/flexaod_v1.0.tgz tar zxvf flexaod_v1.0.tgz
This will create the subdirectory "flexaod_v1.0", here is a quick look at the content:
| Filename/Dirname | Description |
|---|---|
| flexaod.sh | Launch script |
| input.dat | Configuration file |
| pointout.dat | Point output configuration file |
| src/ | Fortran source code |
| src/Makefile.hdr.* | Makefile headers for Fortran compiler configuration |
| data/ | Optical input data (i.e. all but GEOS-Chem timeseries) |
| data/gads/optdat | GADS/OPAC input database (Hess et al., 1998) |
| data/lsmask | Land/sea mask calculated from gridded national IDs (CIESIN and CIAT, 2005), only needed if point_watonly=T |
| data/size_dist | Parameters of size distributions and hygroscopic growth factors |
| data/water | Water spectral refractive index (Segelstein, 1981) |
Set up GEOS-Chem timeseries & data dir
FlexAOD needs GEOS-Chem timeseries in input (instantaneous (ND49) or satellite (ND51)). There is a minimum set of tracers to be saved in output timeseries:
| Aerosol concentrations | Tracer # | Description |
|---|---|---|
| SO4 | 27 | Sulfate |
| NH4 | 31 | Ammonium |
| NIT | 32 | Nitrate |
| BCPI | 34 | Black carbon hydrophillic |
| OCPI | 35 | Primary organic carbon hydrophillic |
| BCPO | 36 | Black carbon hydrophobic |
| OCPO | 37 | Primary organic carbon hydrophobic |
| SOA1-4 | 45-48 | Secondary organic aerosols classes 1-4 |
| DST1-4 | 49-52 | Mineral dust aerosols (size bins 1-4) |
| SSa | 53 | Sea salt aerosols accumulation mode |
| SSc | 54 | Sea salt aerosols coarse mode |
| Meteo fields | Tracer # | Description |
| AIRD | 78 | Air density (molecules/cm^3) |
| BOXH | 93 | Box Height (m) |
| RELH | 94 | Relative Humidity (%) |
| Optional (for comparison with on-line AOD) | Tracer # | Description |
| OPSO4 | 82 | Sulfate aerosols AOD |
| OPBC | 83 | Black carbon AOD |
| OPOC | 84 | Organic carbon AOD |
| OPSSa | 85 | SSa AOD |
| OPSSc | 86 | SSc AOD |
| OPD | 87 | Total dust AOD |
By default, FlexAOD will look for GEOS-Chem output into a subdirectory defined at line 168 of flexaod.sh:
rundir=${HOME}/geos-chem/GEOS-Chem.${ver}.stdrun/runs/${met}.${res}/output/${lab}
where $ver, $met, $res, and $lab are all defined in input.dat. A GEOS-Chem user is familiar with the first three variables, the latter is introduced for further organization of the run directory, but its use is optional. Tailor the naming conventions of the run directory to your needs.
In addition to time series, FlexAOD expects to find under rundir:
tracerinfo.dat.${tlab}
diaginfo.dat.${tlab}
where $tlab is an additional "time label" also defined in input.dat.
Sample GEOS-Chem timeseries output and info files are provided for testing. Go under your "rundir" and download data:
wget -r -nd -np -R*html* http://pumpkin.aquila.infn.it/flexaod/download/testdata
input.dat
Here is a description of the FlexAOD configuration file input.dat:
| Parameter | Description | Examples/Possible values |
|---|---|---|
| ver | GEOS-Chem version | v8-02-02 |
| met | GEOS-Chem met-fields version | geos5 |
| res | GEOS-Chem horizontal resolution | 2x25 |
| compiler | Fortran compiler option | IFORT (used to link to corresponding src/Makefile.hdr.<compiler>) |
| lab | GEOS-Chem simulation label | CTRL (optional, see Set up GEOS-Chem timeseries & data_dir) |
| tlab | GEOS-Chem time label | 200701 (mandatory, see Set up GEOS-Chem timeseries & data_dir) |
| typ | GEOS-Chem timeseries type | inst (ND49) or sat (ND51) |
| dini | Initial date of FlexAOD run | 20070101 (YYYYMMDD) |
| dend | Final date of FlexAOD run | 20070131 (YYYYMMDD) |
| wl | Wavelegth (nm) | 443 (range limited by optical input) |
| optsrc | Optical properties option | OPAC (OPAC/GADS, only option currently) |
| distsrc | Size distribution option | STD (associates to data/size_dist/dist_<distsrc>.dat) |
| hgfsrc | Hygroscopic growth option | OPAC (from OPAC/GADS) or CHIN (from Chin et al, 2002) |
| watsrc | Water refractive index option | SEGEL (Segelstein, 1981, only option currently) |
| fullmie | Mie calculations option | F (create Mie look-up table) or T (Mie calculation for every grid-cell, NOT YET IMPLEMENTED, VERY CPU INTENSIVE!) |
| aodlab | FlexAOD output label | CTRL |
| gridout | Switch for full 3-D output | T or F |
| point_prof | Switch for point profile output | T or F |
| point_rtm | Switch for point RTM output (libRadtran) | T or F |
| point_file | Point output list filename | `pwd`/pointout.dat |
| point_watonly | Point output only over water pixels | T or F |
References
- Center for International Earth Science Information Network (CIESIN), Columbia University; and Centro Internacional de Agricultura Tropical (CIAT) (2005), Gridded Population of the World Version 3 (GPWv3): National Identifier Grid. Palisades, NY: Socioeconomic Data and Applications Center (SEDAC), Columbia University. http://sedac.ciesin.columbia.edu/gpw/
- Chin M, Ginoux P, Kinne S, Torres O, Holben BN, Duncan BN, Martin RV, Logan JA, Higurashi A, Nakajima T (2002), Tropospheric aerosol optical thickness from the GOCART model and comparisons with satellite and Sun photometer measurements, J. Atmos. Sci., 59(3), 461-483. (Table 3 of the paper)
- Hess, M., P. Koepke, and I. Schult (1998), Optical Properties of Aerosols and clouds: The software package OPAC, Bull. Am. Met. Soc., 79, 831-844. http://www.lrz.de/~uh234an/www/radaer/opac.html
- Mishchenko, M. I., J. M. Dlugach, E. G. Yanovitskij, and N. T. Zakharova, (1999), Bidirectional reflectance of flat, optically thick particulate laters: an efficient radiative transfer solution and applications to snow and soil surfaces, J. Quant. Spectrosc. Radiat. Transfer, Vol. 63, 409-432.
- Mishchenko, M. I., L. D. Travis, and A. A. Lacis (2002), Scattering, Absorption, and Emission of Light by Small Particles, Cambridge University Press, Cambridge. http://www.giss.nasa.gov/staff/mmishchenko/brf/
- Segelstein, D. (1981), The Complex Refractive Index of Water, M.S. Thesis, University of Missouri, Kansas City. http://www.philiplaven.com/p20.html