Difference between revisions of "FlexAOD"
(24 intermediate revisions by 2 users not shown) | |||
Line 1: | Line 1: | ||
− | [http://pumpkin.aquila.infn.it/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]]. | + | [http://pumpkin.aquila.infn.it/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]]. For a brief overview, check out the [https://geos-chem.seas.harvard.edu/files/icg5-day1-mond_aerclim_curci_gabriele_1_pc.pdf presentation] at the [https://geos-chem.seas.harvard.edu/geos-meetings-2011-igc5 5th International GEOS-Chem Meeting]! A quick comparison with online GEOS-Chem calculations is given in [http://pumpkin.aquila.infn.it/flexaod/download/FlexAODv1.4.pdf this pdf document]. |
− | |||
== User's Guide == | == User's Guide == | ||
− | === Download code | + | |
− | Source code | + | === Download code === |
− | http://pumpkin.aquila.infn.it/flexaod | + | |
+ | Source code & input data are available at this link: | ||
+ | http://pumpkin.aquila.infn.it/flexaod | ||
From a Linux/Unix terminal, you may follow this procedure: | From a Linux/Unix terminal, you may follow this procedure: | ||
− | mkdir -p geos-chem/flexaod | + | mkdir -p ~/geos-chem/flexaod |
− | cd geos-chem/flexaod | + | cd ~/geos-chem/flexaod |
− | + | tar zxvf flexaod.tgz | |
− | tar zxvf | + | |
− | This will create the subdirectory " | + | This will create the subdirectory "<tt>flexaod_vX.Y</tt>", here is a quick look at the content: |
{| border=1 cellspacing=0 cellpadding=5 | {| border=1 cellspacing=0 cellpadding=5 | ||
Line 29: | Line 29: | ||
|Configuration file | |Configuration file | ||
|- | |- | ||
− | |<tt>pointout.dat</tt> | + | |<tt>[[FlexAOD#pointout.dat|pointout.dat]]</tt> |
− | |Point output configuration file | + | |Point output configuration file (the actual name is set with <tt>point_file</tt> variable) |
+ | |- | ||
+ | |<tt>random_pointout.sh</tt> | ||
+ | |Random <tt>[[FlexAOD#pointout.dat|pointout.dat]]</tt> generator | ||
+ | |- | ||
+ | |<tt>loop.sh</tt> | ||
+ | |Loop script for automatic launch at several wavelengths and/or date intervals | ||
+ | |- | ||
+ | |<tt>loop_wave_rtm.sh</tt> | ||
+ | |Loop script for automatic launch and post-processing of libRadtran output at several wavelengths | ||
|- | |- | ||
|<tt>src/</tt> | |<tt>src/</tt> | ||
Line 46: | Line 55: | ||
|<tt>data/lsmask</tt> | |<tt>data/lsmask</tt> | ||
|Land/sea mask calculated from gridded national IDs (CIESIN and CIAT, 2005), only needed if point_watonly=T | |Land/sea mask calculated from gridded national IDs (CIESIN and CIAT, 2005), only needed if point_watonly=T | ||
+ | |- | ||
+ | |<tt>data/refind</tt> | ||
+ | |Alternative refractive indices databases. From FlexAOD v1.4+ the dust refractive indices from Sinyuk et al. (2003) are used in the standard case. | ||
|- | |- | ||
|<tt>data/size_dist</tt> | |<tt>data/size_dist</tt> | ||
Line 54: | Line 66: | ||
|- | |- | ||
|} | |} | ||
− | |||
=== Set up GEOS-Chem timeseries & data dir === | === Set up GEOS-Chem timeseries & data dir === | ||
+ | |||
+ | ==== GEOS-Chem tracers ==== | ||
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: | 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: | ||
+ | |||
{| border=1 cellspacing=0 cellpadding=5 | {| border=1 cellspacing=0 cellpadding=5 | ||
|- bgcolor="#CCCCCC" | |- bgcolor="#CCCCCC" | ||
!Aerosol concentrations | !Aerosol concentrations | ||
− | !Tracer # | + | !Tracer #<br>(v9-01-01*) |
!Description | !Description | ||
|- | |- | ||
Line 94: | Line 108: | ||
|Primary organic carbon hydrophobic | |Primary organic carbon hydrophobic | ||
|- | |- | ||
− | |SOA1- | + | |SOA1-5 |
− | | | + | |46-50 |
− | |[[Secondary organic aerosols]] classes 1- | + | |[[Secondary organic aerosols]] classes 1-5 |
|- | |- | ||
|DST1-4 | |DST1-4 | ||
− | | | + | |51-54 |
|[[Mineral dust aerosols]] (size bins 1-4) | |[[Mineral dust aerosols]] (size bins 1-4) | ||
|- | |- | ||
|SSa | |SSa | ||
− | | | + | |55 |
|[[Sea salt aerosols]] accumulation mode | |[[Sea salt aerosols]] accumulation mode | ||
|- | |- | ||
|SSc | |SSc | ||
− | | | + | |56 |
|[[Sea salt aerosols]] coarse mode | |[[Sea salt aerosols]] coarse mode | ||
|- bgcolor="#CCCCCC" | |- bgcolor="#CCCCCC" | ||
Line 115: | Line 129: | ||
|- | |- | ||
|AIRD | |AIRD | ||
− | | | + | |80 |
|Air density (molecules/cm^3) | |Air density (molecules/cm^3) | ||
|- | |- | ||
|BOXH | |BOXH | ||
− | | | + | |94 |
|Box Height (m) | |Box Height (m) | ||
|- | |- | ||
|RELH | |RELH | ||
− | | | + | |95 |
|Relative Humidity (%) | |Relative Humidity (%) | ||
|- | |- | ||
Line 132: | Line 146: | ||
|- | |- | ||
|OPSO4 | |OPSO4 | ||
− | | | + | |84 |
|Sulfate aerosols AOD | |Sulfate aerosols AOD | ||
|- | |- | ||
|OPBC | |OPBC | ||
− | | | + | |85 |
|Black carbon AOD | |Black carbon AOD | ||
|- | |- | ||
|OPOC | |OPOC | ||
− | | | + | |86 |
|Organic carbon AOD | |Organic carbon AOD | ||
|- | |- | ||
|OPSSa | |OPSSa | ||
− | | | + | |87 |
|SSa AOD | |SSa AOD | ||
|- | |- | ||
|OPSSc | |OPSSc | ||
− | | | + | |88 |
|SSc AOD | |SSc AOD | ||
|- | |- | ||
|OPD | |OPD | ||
− | | | + | |89 |
|Total dust AOD | |Total dust AOD | ||
|- | |- | ||
|} | |} | ||
+ | <nowiki>*</nowiki>NOTE: tracer # valid for v9-01-01 <tt>SOA</tt> simulation, please check for other simulations and next versions! | ||
+ | ===== Relative humidity timeseries issue ===== | ||
+ | |||
+ | Relative humidity saved in GEOS-Chem timeseries output (ND49-51) differs from that used for on-line calculations of chemistry and aerosol optical depths. This causes ''small differences'' in FlexAOD output with respect to GEOS-Chem on-line calculations for very low AOD values. Have a look at [http://pumpkin.aquila.infn.it/flexaod/download/FlexAODv1.4.pdf this pdf document] to get an idea of the impact of the different RH on AOD calculations. | ||
+ | |||
+ | For a quick fix, do the following modifications to GEOS-Chem code (v9-01-01, under <tt>GeosCore</tt> directory): | ||
+ | |||
+ | In <tt>dao_mod.f</tt>: | ||
+ | |||
+ | .... around line 155 | ||
+ | REAL*8, ALLOCATABLE :: RH(:,:,:) | ||
+ | REAL*8, ALLOCATABLE :: RH_CHEM(:,:,:) <-- add this line | ||
+ | |||
+ | ... around line 2090 | ||
+ | ! Relative humidity | ||
+ | ALLOCATE( RH( IIPAR, JJPAR, LLPAR ), STAT=AS ) | ||
+ | IF ( AS /= 0 ) CALL ALLOC_ERR( 'RH' ) | ||
+ | RH = 0d0 | ||
+ | |||
+ | ! Relative humidity used in chemistry (gcc rh, 7/10) <-- add these lines | ||
+ | ALLOCATE( RH_CHEM( IIPAR, JJPAR, LLPAR ), STAT=AS ) <-- | ||
+ | IF ( AS /= 0 ) CALL ALLOC_ERR( 'RH_CHEM' ) <-- | ||
+ | RH_CHEM = 0d0 <-- | ||
+ | |||
+ | ... around line 2763 | ||
+ | IF ( ALLOCATED( RH ) ) DEALLOCATE( RH ) | ||
+ | IF ( ALLOCATED( RH_CHEM ) ) DEALLOCATE( RH_CHEM ) <-- add this line | ||
+ | |||
+ | In <tt>aerosol_mod.f</tt>: | ||
+ | |||
+ | ... around line 544 | ||
+ | USE DAO_MOD, ONLY : BXHEIGHT | ||
+ | USE DAO_MOD, ONLY : RH_CHEM <-- add this line | ||
+ | |||
+ | ... around line 923 | ||
+ | ! Store RH_CHEM | ||
+ | DO JLOOP = 1, NTLOOP | ||
+ | |||
+ | ! Get 3-D grid box indices | ||
+ | I = IXSAVE(JLOOP) | ||
+ | J = IYSAVE(JLOOP) | ||
+ | L = IZSAVE(JLOOP) | ||
+ | |||
+ | ! Copy onto output array | ||
+ | RH_CHEM(I, J, L) = ABSHUM(JLOOP) * 1d2 | ||
+ | |||
+ | ENDDO | ||
+ | |||
+ | In <tt>diag49_mod.f</tt> | ||
+ | |||
+ | ... around line 176 | ||
+ | USE DAO_MOD, ONLY : CLDTOPS, OPTD, RH, SLP | ||
+ | USE DAO_MOD, ONLY : RH_CHEM <-- add this line | ||
+ | |||
+ | ... around line 948 | ||
+ | !Q(X,Y,K) = RH(I,J,L) <-- comment this line | ||
+ | Q(X,Y,K) = RH_CHEM(I,J,L) <-- add this line | ||
+ | |||
+ | |||
+ | In <tt>diag51_mod.f</tt>: | ||
+ | |||
+ | ... around line 358 | ||
+ | USE DAO_MOD, ONLY : UWND, VWND, SLP | ||
+ | USE DAO_MOD, ONLY : RH_CHEM <-- add this line | ||
+ | |||
+ | ... around line 856 | ||
+ | !Q(X,Y,K,W) = Q(X,Y,K,W) + ( RH(I,J,L) * GOOD(I) ) <-- comment this line | ||
+ | Q(X,Y,K,W) = Q(X,Y,K,W) + ( RH_CHEM(I,J,L) * GOOD(I) ) <-- add this line | ||
+ | |||
+ | ==== GEOS-Chem rundir ==== | ||
By default, FlexAOD will look for GEOS-Chem output into a subdirectory defined at line 168 of <tt>flexaod.sh</tt>: | By default, FlexAOD will look for GEOS-Chem output into a subdirectory defined at line 168 of <tt>flexaod.sh</tt>: | ||
Line 162: | Line 246: | ||
rundir=${HOME}/geos-chem/GEOS-Chem.${ver}.stdrun/runs/${met}.${res}/output/${lab} | rundir=${HOME}/geos-chem/GEOS-Chem.${ver}.stdrun/runs/${met}.${res}/output/${lab} | ||
− | where $ver, $met, $res, and $lab are all defined in [[FlexAOD#input.dat|input.dat]]. A GEOS-Chem user is familiar with the first three variables, the latter is introduced for further organization of the run directory, but its use is optional. Tailor the naming conventions of the run directory to your needs. | + | where <tt>$ver</tt>, <tt>$met</tt>, <tt>$res</tt>, and <tt>$lab</tt> are all defined in <tt>[[FlexAOD#input.dat|input.dat]]</tt>. A GEOS-Chem user is familiar with the first three variables, the latter is introduced for further organization of the run directory, but its use is optional. Tailor the naming conventions of the run directory to your needs. |
− | In addition to time series, FlexAOD expects to find under rundir: | + | In addition to time series, FlexAOD expects to find under <tt>rundir</tt>: |
tracerinfo.dat.${tlab} | tracerinfo.dat.${tlab} | ||
diaginfo.dat.${tlab} | diaginfo.dat.${tlab} | ||
− | where $tlab is an additional "time label" also defined in [[FlexAOD#input.dat|input.dat]]. | + | where <tt>$tlab</tt> is an additional "time label" also defined in <tt>[[FlexAOD#input.dat|input.dat]]</tt>. Please rename your <tt>*info.dat</tt> accordingly. |
− | Sample GEOS-Chem timeseries output and info files are provided for testing. | + | Sample GEOS-Chem timeseries output and info files are provided for testing under: http://pumpkin.aquila.infn.it/flexaod/download/testdata |
+ | |||
+ | From shell, go under your "rundir" and you may download all data with: | ||
wget -r -nd -np -R*html* http://pumpkin.aquila.infn.it/flexaod/download/testdata | wget -r -nd -np -R*html* http://pumpkin.aquila.infn.it/flexaod/download/testdata | ||
+ | |||
+ | |||
+ | ===== Optional GEOS-Chem launch script ===== | ||
+ | |||
+ | A launch script for GEOS-Chem model is provided with FlexAOD in order to: | ||
+ | *launch the simulation within your <tt>rundir</tt> | ||
+ | *move/rename the output files after run in an output directory suitable for FlexAOD (see [[FlexAOD#GEOS-Chem rundir|GEOS-Chem rundir]]) | ||
+ | You may download and launch the script with: | ||
+ | wget http://pumpkin.aquila.infn.it/flexaod/download/run_geos.sh | ||
+ | ./run_geos.sh <lab> <tlab> | ||
+ | where <tt><lab></tt> and <tt><tlab></tt> are the simulation and time labels to subsequently set into <tt>[[FlexAOD#input.dat|input.dat]]</tt> for use with FlexAOD. | ||
Line 187: | Line 284: | ||
|<tt>ver</tt> | |<tt>ver</tt> | ||
|GEOS-Chem version | |GEOS-Chem version | ||
− | |<tt> | + | |<tt>v9-01-01</tt> |
|- | |- | ||
|<tt>met</tt> | |<tt>met</tt> | ||
Line 195: | Line 292: | ||
|<tt>res</tt> | |<tt>res</tt> | ||
|GEOS-Chem horizontal resolution | |GEOS-Chem horizontal resolution | ||
− | |<tt> | + | |<tt>2x2.5</tt> |
+ | |- | ||
+ | |<tt>sim</tt> | ||
+ | |GEOS-Chem simulation | ||
+ | |<tt>SOA</tt> | ||
|- | |- | ||
|<tt>compiler</tt> | |<tt>compiler</tt> | ||
Line 227: | Line 328: | ||
|<tt>optsrc</tt> | |<tt>optsrc</tt> | ||
|Optical properties option | |Optical properties option | ||
− | |<tt> | + | |<tt>STD</tt> (OPAC/GADS, with modifications as online) or<br><tt>OPAC</tt> (OPAC/GADS) |
|- | |- | ||
|<tt>distsrc</tt> | |<tt>distsrc</tt> | ||
Line 235: | Line 336: | ||
|<tt>hgfsrc</tt> | |<tt>hgfsrc</tt> | ||
|Hygroscopic growth option | |Hygroscopic growth option | ||
− | |<tt>OPAC</tt> (from OPAC/GADS) or<br><tt>CHIN</tt> (from Chin et al, 2002) | + | |<tt>STD</tt> (from OPAC/GADS, with modifications as online) or<br><tt>OPAC</tt> (from OPAC/GADS) or<br><tt>CHIN</tt> (from Chin et al, 2002) |
|- | |- | ||
|<tt>watsrc</tt> | |<tt>watsrc</tt> | ||
|Water refractive index option | |Water refractive index option | ||
− | |<tt>SEGEL</tt> (Segelstein | + | |<tt>STD</tt> (as online: fixed at <tt>1.33+i*0.0</tt>) or<br><tt>SEGEL</tt> (Segelstein (1981), spectrally varying index) |
|- | |- | ||
|<tt>fullmie</tt> | |<tt>fullmie</tt> | ||
Line 247: | Line 348: | ||
|<tt>aodlab</tt> | |<tt>aodlab</tt> | ||
|FlexAOD output label | |FlexAOD output label | ||
− | |<tt> | + | |<tt>STD</tt> |
|- | |- | ||
|<tt>gridout</tt> | |<tt>gridout</tt> | ||
Line 271: | Line 372: | ||
|} | |} | ||
+ | === pointout.dat === | ||
+ | |||
+ | The <tt>pointout.dat</tt> contains the list of points (time and place) for FlexAOD point output. The actual name of the file may vary and is set with variable <tt>point_file</tt> in <tt>[[FlexAOD#input.dat|input.dat]]</tt>. | ||
+ | |||
+ | The format (free ASCII format) of the file is the following: | ||
+ | |||
+ | :column 1: point number | ||
+ | :column 2: time (YYYYMMDDHH) | ||
+ | :column 3: latitude (degrees north) | ||
+ | :column 4: longitude (degrees east) | ||
+ | |||
+ | Here is an example: | ||
+ | |||
+ | # N Date/hour Lat Lon | ||
+ | # (YYYYMMDDHH) (deg N) (deg E) | ||
+ | 1 2006010109 42.0 13.0 | ||
+ | 2 2006010110 42.0 -33.0 | ||
+ | |||
+ | All the lines beginning with "<tt>#</tt>" will be removed by FlexAOD. | ||
+ | |||
+ | The utility <tt>random_pointout.sh</tt> generates a random list of points, between user defined dates and coordinates, that may be used for testing or random data model extraction. | ||
+ | |||
+ | |||
+ | === Program Launch === | ||
+ | |||
+ | Once you set up <tt>[[FlexAOD#input.dat|input.dat]]</tt> and, optionally, <tt>[[FlexAOD#pointout.dat|pointout.dat]]</tt>, launch FlexAOD from a shell: | ||
+ | |||
+ | ./flexaod.sh | ||
+ | |||
+ | or, if you want a background job and log file (bash syntax): | ||
+ | |||
+ | ./flexaod.sh &> log & | ||
+ | tail -f log | ||
+ | |||
+ | The utility <tt>loop.sh</tt> allows automatic FlexAOD launch for several user selected wavelengths and time periods. The <tt>loop_wave_rtm.sh</tt> is for specific use with <tt>point_rtm=T</tt> option: it will paste in a unique file the output of several wavelengths. | ||
+ | |||
+ | |||
+ | === FlexAOD output === | ||
+ | |||
+ | Similarly to [[Aerosol optical properties|GEOS-Chem on-line AOD calculations]], FlexAOD performs calculations for 6 "optical" species, assumed in external mixing state: | ||
+ | |||
+ | {| border=1 cellspacing=0 cellpadding=5 | ||
+ | |- bgcolor="#CCCCCC" | ||
+ | !"Optical" species | ||
+ | ![[FlexAOD#GEOS-Chem tracers|GEOS-Chem tracers]] included | ||
+ | |- | ||
+ | |SULF | ||
+ | |SO4, NH4, NIT | ||
+ | |- | ||
+ | |OC | ||
+ | |OCPI, OCPO, SOA1-5 | ||
+ | |- | ||
+ | |BC | ||
+ | |BCPI, BCPO | ||
+ | |- | ||
+ | |SSa | ||
+ | |SSa | ||
+ | |- | ||
+ | |SSc | ||
+ | |SSc | ||
+ | |- | ||
+ | |DUST | ||
+ | |DST1-4 | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | FlexAOD has the following types of user selected output: | ||
+ | |||
+ | {| border=1 cellspacing=0 cellpadding=5 | ||
+ | |- bgcolor="#CCCCCC" | ||
+ | !Description | ||
+ | !<tt>[[FlexAOD#input.dat|input.dat]]</tt> option | ||
+ | !default output dir | ||
+ | !sample file name | ||
+ | !output variables | ||
+ | |- | ||
+ | |Full 3-D gridded output | ||
+ | |<tt>gridout=T</tt> | ||
+ | |<tt>[[FlexAOD#GEOS-Chem rundir|<rundir>]]/../GrADS</tt> | ||
+ | |<tt>ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>.ctl/dat</tt> | ||
+ | |AOD of "optical" species (same as GEOS-Chem on-line output), plus backscattering efficiency, single-scattering albedo and asymmetry factor | ||
+ | [[FlexAOD#Gridded (GrADS) output|[details]]] | ||
+ | |- | ||
+ | |Profile at selected points | ||
+ | |<tt>point_prof=T</tt><br><tt>point_file=<filename></tt> | ||
+ | |<tt>[[FlexAOD#GEOS-Chem rundir|<rundir>]]/../PROFILES</tt> | ||
+ | |<tt>ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>_000012</tt> | ||
+ | |Profile of mass concentrations, number concentration; extinction, scattering and backscattering coefficients; single-scattering albedo; asymmetry factor; phase function coefficients | ||
+ | [[FlexAOD#Profile output|[details]]] | ||
+ | |- | ||
+ | |Profile at selected points for use with RTM (libRadtran) | ||
+ | |<tt>point_rtm=T</tt><br><tt>point_file=<filename></tt> | ||
+ | |<tt>[[FlexAOD#GEOS-Chem rundir|<rundir>]]/../libRadtran</tt> | ||
+ | |<tt>ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>_000012_FILES</tt> (list of files with model level info)<br> | ||
+ | <tt>ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>_CONC</tt> ("optical" species mass column, g/m^2)<br> | ||
+ | |extinction coefficient, single-scattering albedo, phase function coefficients | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | Any number of output types may be requested (at least one!). | ||
+ | |||
+ | |||
+ | ==== Gridded (GrADS) output ==== | ||
+ | |||
+ | The <tt>.ctl/.dat</tt> pairs generated for gridded GrADS binary output may be used for direct visualization and analysis in [http://www.iges.org/grads/ GrADS]. Activate this option only if you really need 3D output. If you need output only at selected points/times much better using [[FlexAOD#pointout.dat|point profile output]], which saves a lot of time performing calculations only at desired points. | ||
+ | |||
+ | If you don't like GrADS, you may read data with other computer languages, such as Fortran: | ||
+ | |||
+ | program read_grads | ||
+ | |||
+ | ! Parameters | ||
+ | integer,paramter :: iou = 10 ! I/O unit | ||
+ | integer,paramter :: ni = 144 ! n. lons | ||
+ | integer,paramter :: nj = 91 ! n. lats | ||
+ | integer,paramter :: nl = 38 ! n. levs | ||
+ | integer,paramter :: nspecs = 6 ! n. specs | ||
+ | integer,paramter :: ntimes = 5 ! n. times | ||
+ | |||
+ | ! Arrays | ||
+ | real, dimension(ni,nj) :: aottot, ssatot, asymtot | ||
+ | real, dimension(ni,nj,nl) :: kback, ssa, asym, boxh | ||
+ | real, dimension(ni,nj,nl,nspecs) :: aot | ||
+ | |||
+ | |||
+ | ! Open file in "binary" mode | ||
+ | open(iou, file="<filename>", status="old", form="binary") | ||
+ | |||
+ | ! Loop over times | ||
+ | do it = 1, ntimes | ||
+ | |||
+ | ! AOT [ni x nj] | ||
+ | read(iou) aottot | ||
+ | |||
+ | ! Column averaged Single-Scattering Albedo [ni x nj] | ||
+ | read(iou) ssatot | ||
+ | |||
+ | ! Column averaged Asymmetry Factor [ni x nj] | ||
+ | read(iou) asymtot | ||
+ | |||
+ | ! Optical Depths of single species [ni x nj x nl x nspecs] | ||
+ | ! Species order: SULF, OC, BC, SSa, SSc, DUST | ||
+ | do k=1,nspecs | ||
+ | do l=1,nl | ||
+ | read(iou) aot(:,:,l,k) | ||
+ | enddo | ||
+ | enddo | ||
+ | |||
+ | ! 3D Back-scattering efficiency (1/(km srad)) [ni x nj x nl] | ||
+ | do l=1,nl | ||
+ | read(iou) kback(:,:,l) | ||
+ | enddo | ||
+ | |||
+ | ! 3D Single-Scatteting Albedo [ni x nj x nl] | ||
+ | do l=1,nl | ||
+ | read(iou) ssa(:,:,l) | ||
+ | enddo | ||
+ | |||
+ | ! 3D Asymmetry Factor [ni x nj x nl] | ||
+ | do l=1,nl | ||
+ | read(iou) asym(:,:,l) | ||
+ | enddo | ||
+ | |||
+ | ! Box Height (m) [ni x nj x nl] | ||
+ | do l=1,nl | ||
+ | read(iou) boxh(:,:,l) | ||
+ | enddo | ||
+ | |||
+ | enddo ! times | ||
+ | |||
+ | ! Close file | ||
+ | close(iou) | ||
+ | |||
+ | end program read_grads | ||
+ | |||
+ | If your Fortran compiler does not understand the "binary" form, then just change it to "unformatted" at line 547 of <tt>src/flexaod.f90</tt>. In that case, however, you will NOT be able to use the output with GrADS. | ||
+ | |||
+ | ==== Profile output ==== | ||
+ | |||
+ | Profile output (<tt>point_prof=T</tt>) is much easier to handle, because it is in ASCII format. One file per point specified in <tt>[[FlexAOD#pointout.dat|pointout.dat]]</tt> list is generated. Each file thus contains the calculated profile for a given time/place. | ||
+ | |||
+ | Each output file has <tt>nl+1</tt> rows, where <tt>nl</tt> is the number of levels in GEOS-Chem timeseries. Here is the content of rows: | ||
+ | * '''1st row:''' column average/integrated values | ||
+ | * '''2nd to (<tt>nl+1</tt>)th row:''' values at model levels | ||
+ | |||
+ | Let <tt>nspecs = 6</tt> the number of "optical" species and <tt>noutpc</tt> is the number of output coefficients (default is 16, set at line <tt>1431</tt> of <tt>src/flexaod.f90</tt>). | ||
+ | |||
+ | Output variables for '''1st row''' are: | ||
+ | * '''column 1:''' 0.000 | ||
+ | * '''column 2 to <tt>nspecs+1</tt>:''' column concentrations of "optical" species (g/m^2) | ||
+ | * '''column <tt>nspecs+2</tt>:''' column number concentration (#/cm^2) | ||
+ | * '''column <tt>nspecs+3</tt>:''' aerosol optical depth (unitless) | ||
+ | * '''column <tt>nspecs+4</tt>:''' scattering aerosol optical depth (unitless) | ||
+ | * '''column <tt>nspecs+5</tt>:''' back-scattering aerosol optical depth (unitless) | ||
+ | * '''column <tt>nspecs+6</tt>:''' column-weighted single-scattering albedo (unitless) | ||
+ | * '''column <tt>nspecs+7</tt>:''' column-weighted asymmetry factor (unitless) | ||
+ | * '''column <tt>nspecs+8</tt> to <tt>nspecs+8+noutpc-1</tt>:''' column-weighted phase function coefficients (unitless) | ||
+ | |||
+ | Output variables for '''other rows''' are: | ||
+ | * '''column 1:''' GEOS-Chem level height (km) | ||
+ | * '''column 2 to <tt>nspecs+1</tt>:''' mass concentrations of "optical" species (ug/m^3) | ||
+ | * '''column <tt>nspecs+2</tt>:''' number concentration (#/cm^3) | ||
+ | * '''column <tt>nspecs+3</tt>:''' extinction coefficient (1/km) | ||
+ | * '''column <tt>nspecs+4</tt>:''' scattering coefficient (1/km) | ||
+ | * '''column <tt>nspecs+5</tt>:''' back-scattering coefficient (1/(km srad)) | ||
+ | * '''column <tt>nspecs+6</tt>:''' single-scattering albedo (unitless) | ||
+ | * '''column <tt>nspecs+7</tt>:''' asymmetry factor (unitless) | ||
+ | * '''column <tt>nspecs+8</tt> to <tt>nspecs+8+noutpc-1</tt>:''' phase function coefficients (unitless) | ||
+ | |||
+ | == Usage remarks == | ||
+ | |||
+ | FlexAOD is still under devolopment, so it will hopefully expand its capabilities in the next months. Users are encouraged to return with bug reports, feedback, and suggestions. | ||
+ | |||
+ | At present stage, running FlexAOD with [[FlexAOD#Relative humidity timeseries issue|corrected GEOS-Chem RH timeseries]] and these options: | ||
+ | optsrc=STD | ||
+ | distsrc=STD | ||
+ | hgfsrc=STD | ||
+ | watsrc=STD | ||
+ | reproduces the on-line standard calculations, with negligible differences for very low AOD values (still not completely sure why). | ||
+ | |||
+ | In addition to on-line calculation, you can easily do: | ||
+ | #Extract selected profiles of additional variables, such as backscattering coefficients or single scattering albedo (see [[FlexAOD#Point output|Point output]]) | ||
+ | #Calculate aerosol optical properties for several wavelengths avoiding repeated GEOS-Chem simulations | ||
+ | #Modify the size-distribution and hygroscopic properties of species (adding cases to <tt>data/size_dist</tt>) | ||
+ | |||
+ | Full flexibility of usage is reached with instantaneous timeseries (ND49, <tt>typ=inst</tt>) with hourly output, which allow perfect replication of on-line AOD calculation procedure. Hourly timeseries obviously require a lot of disk space. One may reduce disk usage by setting output frequency at e.g. 3 or 6 hours, but in that case FlexAOD output cannot be calculated for any hour of the day of course. | ||
+ | |||
+ | Satellite timeseries (ND51, <tt>typ=sat</tt>) is better used with 1 hour interval (e.g. 9-10 LT), in order again to replicate on-line AOD calculations. Using averaging interval larger than 1 hour will yield differences with respect to on-line AOD, because averaged values of aerosol concentrations and relative humidities will be used by FlexAOD. | ||
+ | |||
+ | Note on <tt>gridout</tt> option: activate this option only if you really need [[FlexAOD#Gridded (GrADS) output|3D output]]. If you need output only at selected points/times much better using [[FlexAOD#pointout.dat|point profile output]], which saves a lot of time performing calculations only at desired points. | ||
+ | |||
+ | |||
+ | --[[User:Gabriele.curci|gcc]] 12:05, 25 May 2011 (EDT) | ||
== References == | == References == | ||
Line 280: | Line 614: | ||
#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/ | #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 | #Segelstein, D. (1981), The Complex Refractive Index of Water, M.S. Thesis, University of Missouri, Kansas City. http://www.philiplaven.com/p20.html | ||
+ | #Sinyuk, A., O. Torres, and O. Dubovik (2003), Combined use of satellite and surface observations to infer the imaginary part of the refractive index of Saharan dust, Geophys. Res. Lett., 30(2), 1081. |
Latest revision as of 20:58, 20 September 2022
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. For a brief overview, check out the presentation at the 5th International GEOS-Chem Meeting! A quick comparison with online GEOS-Chem calculations is given in this pdf document.
Contents
User's Guide
Download code
Source code & input data are available at this link: http://pumpkin.aquila.infn.it/flexaod
From a Linux/Unix terminal, you may follow this procedure:
mkdir -p ~/geos-chem/flexaod cd ~/geos-chem/flexaod tar zxvf flexaod.tgz
This will create the subdirectory "flexaod_vX.Y", 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 (the actual name is set with point_file variable) |
random_pointout.sh | Random pointout.dat generator |
loop.sh | Loop script for automatic launch at several wavelengths and/or date intervals |
loop_wave_rtm.sh | Loop script for automatic launch and post-processing of libRadtran output at several wavelengths |
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/refind | Alternative refractive indices databases. From FlexAOD v1.4+ the dust refractive indices from Sinyuk et al. (2003) are used in the standard case. |
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
GEOS-Chem tracers
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 # (v9-01-01*) |
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 |
SOA1-5 | 46-50 | Secondary organic aerosols classes 1-5 |
DST1-4 | 51-54 | Mineral dust aerosols (size bins 1-4) |
SSa | 55 | Sea salt aerosols accumulation mode |
SSc | 56 | Sea salt aerosols coarse mode |
Meteo fields | Tracer # | Description |
AIRD | 80 | Air density (molecules/cm^3) |
BOXH | 94 | Box Height (m) |
RELH | 95 | Relative Humidity (%) |
Optional (for comparison with on-line AOD) | Tracer # | Description |
OPSO4 | 84 | Sulfate aerosols AOD |
OPBC | 85 | Black carbon AOD |
OPOC | 86 | Organic carbon AOD |
OPSSa | 87 | SSa AOD |
OPSSc | 88 | SSc AOD |
OPD | 89 | Total dust AOD |
*NOTE: tracer # valid for v9-01-01 SOA simulation, please check for other simulations and next versions!
Relative humidity timeseries issue
Relative humidity saved in GEOS-Chem timeseries output (ND49-51) differs from that used for on-line calculations of chemistry and aerosol optical depths. This causes small differences in FlexAOD output with respect to GEOS-Chem on-line calculations for very low AOD values. Have a look at this pdf document to get an idea of the impact of the different RH on AOD calculations.
For a quick fix, do the following modifications to GEOS-Chem code (v9-01-01, under GeosCore directory):
In dao_mod.f:
.... around line 155 REAL*8, ALLOCATABLE :: RH(:,:,:) REAL*8, ALLOCATABLE :: RH_CHEM(:,:,:) <-- add this line ... around line 2090 ! Relative humidity ALLOCATE( RH( IIPAR, JJPAR, LLPAR ), STAT=AS ) IF ( AS /= 0 ) CALL ALLOC_ERR( 'RH' ) RH = 0d0 ! Relative humidity used in chemistry (gcc rh, 7/10) <-- add these lines ALLOCATE( RH_CHEM( IIPAR, JJPAR, LLPAR ), STAT=AS ) <-- IF ( AS /= 0 ) CALL ALLOC_ERR( 'RH_CHEM' ) <-- RH_CHEM = 0d0 <-- ... around line 2763 IF ( ALLOCATED( RH ) ) DEALLOCATE( RH ) IF ( ALLOCATED( RH_CHEM ) ) DEALLOCATE( RH_CHEM ) <-- add this line
In aerosol_mod.f:
... around line 544 USE DAO_MOD, ONLY : BXHEIGHT USE DAO_MOD, ONLY : RH_CHEM <-- add this line ... around line 923 ! Store RH_CHEM DO JLOOP = 1, NTLOOP ! Get 3-D grid box indices I = IXSAVE(JLOOP) J = IYSAVE(JLOOP) L = IZSAVE(JLOOP) ! Copy onto output array RH_CHEM(I, J, L) = ABSHUM(JLOOP) * 1d2 ENDDO
In diag49_mod.f
... around line 176 USE DAO_MOD, ONLY : CLDTOPS, OPTD, RH, SLP USE DAO_MOD, ONLY : RH_CHEM <-- add this line ... around line 948 !Q(X,Y,K) = RH(I,J,L) <-- comment this line Q(X,Y,K) = RH_CHEM(I,J,L) <-- add this line
In diag51_mod.f:
... around line 358 USE DAO_MOD, ONLY : UWND, VWND, SLP USE DAO_MOD, ONLY : RH_CHEM <-- add this line ... around line 856 !Q(X,Y,K,W) = Q(X,Y,K,W) + ( RH(I,J,L) * GOOD(I) ) <-- comment this line Q(X,Y,K,W) = Q(X,Y,K,W) + ( RH_CHEM(I,J,L) * GOOD(I) ) <-- add this line
GEOS-Chem rundir
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. Please rename your *info.dat accordingly.
Sample GEOS-Chem timeseries output and info files are provided for testing under: http://pumpkin.aquila.infn.it/flexaod/download/testdata
From shell, go under your "rundir" and you may download all data with:
wget -r -nd -np -R*html* http://pumpkin.aquila.infn.it/flexaod/download/testdata
Optional GEOS-Chem launch script
A launch script for GEOS-Chem model is provided with FlexAOD in order to:
- launch the simulation within your rundir
- move/rename the output files after run in an output directory suitable for FlexAOD (see GEOS-Chem rundir)
You may download and launch the script with:
wget http://pumpkin.aquila.infn.it/flexaod/download/run_geos.sh ./run_geos.sh <lab> <tlab>
where <lab> and <tlab> are the simulation and time labels to subsequently set into input.dat for use with FlexAOD.
input.dat
Here is a description of the FlexAOD configuration file input.dat:
Parameter | Description | Examples/Possible values |
---|---|---|
ver | GEOS-Chem version | v9-01-01 |
met | GEOS-Chem met-fields version | geos5 |
res | GEOS-Chem horizontal resolution | 2x2.5 |
sim | GEOS-Chem simulation | SOA |
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 | STD (OPAC/GADS, with modifications as online) or OPAC (OPAC/GADS) |
distsrc | Size distribution option | STD (associates to data/size_dist/dist_<distsrc>.dat) |
hgfsrc | Hygroscopic growth option | STD (from OPAC/GADS, with modifications as online) or OPAC (from OPAC/GADS) or CHIN (from Chin et al, 2002) |
watsrc | Water refractive index option | STD (as online: fixed at 1.33+i*0.0) or SEGEL (Segelstein (1981), spectrally varying index) |
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 | STD |
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 |
pointout.dat
The pointout.dat contains the list of points (time and place) for FlexAOD point output. The actual name of the file may vary and is set with variable point_file in input.dat.
The format (free ASCII format) of the file is the following:
- column 1: point number
- column 2: time (YYYYMMDDHH)
- column 3: latitude (degrees north)
- column 4: longitude (degrees east)
Here is an example:
# N Date/hour Lat Lon # (YYYYMMDDHH) (deg N) (deg E) 1 2006010109 42.0 13.0 2 2006010110 42.0 -33.0
All the lines beginning with "#" will be removed by FlexAOD.
The utility random_pointout.sh generates a random list of points, between user defined dates and coordinates, that may be used for testing or random data model extraction.
Program Launch
Once you set up input.dat and, optionally, pointout.dat, launch FlexAOD from a shell:
./flexaod.sh
or, if you want a background job and log file (bash syntax):
./flexaod.sh &> log & tail -f log
The utility loop.sh allows automatic FlexAOD launch for several user selected wavelengths and time periods. The loop_wave_rtm.sh is for specific use with point_rtm=T option: it will paste in a unique file the output of several wavelengths.
FlexAOD output
Similarly to GEOS-Chem on-line AOD calculations, FlexAOD performs calculations for 6 "optical" species, assumed in external mixing state:
"Optical" species | GEOS-Chem tracers included |
---|---|
SULF | SO4, NH4, NIT |
OC | OCPI, OCPO, SOA1-5 |
BC | BCPI, BCPO |
SSa | SSa |
SSc | SSc |
DUST | DST1-4 |
FlexAOD has the following types of user selected output:
Description | input.dat option | default output dir | sample file name | output variables |
---|---|---|---|---|
Full 3-D gridded output | gridout=T | <rundir>/../GrADS | ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>.ctl/dat | AOD of "optical" species (same as GEOS-Chem on-line output), plus backscattering efficiency, single-scattering albedo and asymmetry factor |
Profile at selected points | point_prof=T point_file=<filename> |
<rundir>/../PROFILES | ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>_000012 | Profile of mass concentrations, number concentration; extinction, scattering and backscattering coefficients; single-scattering albedo; asymmetry factor; phase function coefficients |
Profile at selected points for use with RTM (libRadtran) | point_rtm=T point_file=<filename> |
<rundir>/../libRadtran | ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>_000012_FILES (list of files with model level info) ts_satellite_<tlab>_<lab>_<dini>-<dend>_<wl>nm_<aodlab>_CONC ("optical" species mass column, g/m^2) |
extinction coefficient, single-scattering albedo, phase function coefficients |
Any number of output types may be requested (at least one!).
Gridded (GrADS) output
The .ctl/.dat pairs generated for gridded GrADS binary output may be used for direct visualization and analysis in GrADS. Activate this option only if you really need 3D output. If you need output only at selected points/times much better using point profile output, which saves a lot of time performing calculations only at desired points.
If you don't like GrADS, you may read data with other computer languages, such as Fortran:
program read_grads ! Parameters integer,paramter :: iou = 10 ! I/O unit integer,paramter :: ni = 144 ! n. lons integer,paramter :: nj = 91 ! n. lats integer,paramter :: nl = 38 ! n. levs integer,paramter :: nspecs = 6 ! n. specs integer,paramter :: ntimes = 5 ! n. times ! Arrays real, dimension(ni,nj) :: aottot, ssatot, asymtot real, dimension(ni,nj,nl) :: kback, ssa, asym, boxh real, dimension(ni,nj,nl,nspecs) :: aot ! Open file in "binary" mode open(iou, file="<filename>", status="old", form="binary") ! Loop over times do it = 1, ntimes ! AOT [ni x nj] read(iou) aottot ! Column averaged Single-Scattering Albedo [ni x nj] read(iou) ssatot ! Column averaged Asymmetry Factor [ni x nj] read(iou) asymtot ! Optical Depths of single species [ni x nj x nl x nspecs] ! Species order: SULF, OC, BC, SSa, SSc, DUST do k=1,nspecs do l=1,nl read(iou) aot(:,:,l,k) enddo enddo ! 3D Back-scattering efficiency (1/(km srad)) [ni x nj x nl] do l=1,nl read(iou) kback(:,:,l) enddo ! 3D Single-Scatteting Albedo [ni x nj x nl] do l=1,nl read(iou) ssa(:,:,l) enddo ! 3D Asymmetry Factor [ni x nj x nl] do l=1,nl read(iou) asym(:,:,l) enddo ! Box Height (m) [ni x nj x nl] do l=1,nl read(iou) boxh(:,:,l) enddo enddo ! times ! Close file close(iou) end program read_grads
If your Fortran compiler does not understand the "binary" form, then just change it to "unformatted" at line 547 of src/flexaod.f90. In that case, however, you will NOT be able to use the output with GrADS.
Profile output
Profile output (point_prof=T) is much easier to handle, because it is in ASCII format. One file per point specified in pointout.dat list is generated. Each file thus contains the calculated profile for a given time/place.
Each output file has nl+1 rows, where nl is the number of levels in GEOS-Chem timeseries. Here is the content of rows:
- 1st row: column average/integrated values
- 2nd to (nl+1)th row: values at model levels
Let nspecs = 6 the number of "optical" species and noutpc is the number of output coefficients (default is 16, set at line 1431 of src/flexaod.f90).
Output variables for 1st row are:
- column 1: 0.000
- column 2 to nspecs+1: column concentrations of "optical" species (g/m^2)
- column nspecs+2: column number concentration (#/cm^2)
- column nspecs+3: aerosol optical depth (unitless)
- column nspecs+4: scattering aerosol optical depth (unitless)
- column nspecs+5: back-scattering aerosol optical depth (unitless)
- column nspecs+6: column-weighted single-scattering albedo (unitless)
- column nspecs+7: column-weighted asymmetry factor (unitless)
- column nspecs+8 to nspecs+8+noutpc-1: column-weighted phase function coefficients (unitless)
Output variables for other rows are:
- column 1: GEOS-Chem level height (km)
- column 2 to nspecs+1: mass concentrations of "optical" species (ug/m^3)
- column nspecs+2: number concentration (#/cm^3)
- column nspecs+3: extinction coefficient (1/km)
- column nspecs+4: scattering coefficient (1/km)
- column nspecs+5: back-scattering coefficient (1/(km srad))
- column nspecs+6: single-scattering albedo (unitless)
- column nspecs+7: asymmetry factor (unitless)
- column nspecs+8 to nspecs+8+noutpc-1: phase function coefficients (unitless)
Usage remarks
FlexAOD is still under devolopment, so it will hopefully expand its capabilities in the next months. Users are encouraged to return with bug reports, feedback, and suggestions.
At present stage, running FlexAOD with corrected GEOS-Chem RH timeseries and these options:
optsrc=STD distsrc=STD hgfsrc=STD watsrc=STD
reproduces the on-line standard calculations, with negligible differences for very low AOD values (still not completely sure why).
In addition to on-line calculation, you can easily do:
- Extract selected profiles of additional variables, such as backscattering coefficients or single scattering albedo (see Point output)
- Calculate aerosol optical properties for several wavelengths avoiding repeated GEOS-Chem simulations
- Modify the size-distribution and hygroscopic properties of species (adding cases to data/size_dist)
Full flexibility of usage is reached with instantaneous timeseries (ND49, typ=inst) with hourly output, which allow perfect replication of on-line AOD calculation procedure. Hourly timeseries obviously require a lot of disk space. One may reduce disk usage by setting output frequency at e.g. 3 or 6 hours, but in that case FlexAOD output cannot be calculated for any hour of the day of course.
Satellite timeseries (ND51, typ=sat) is better used with 1 hour interval (e.g. 9-10 LT), in order again to replicate on-line AOD calculations. Using averaging interval larger than 1 hour will yield differences with respect to on-line AOD, because averaged values of aerosol concentrations and relative humidities will be used by FlexAOD.
Note on gridout option: activate this option only if you really need 3D output. If you need output only at selected points/times much better using point profile output, which saves a lot of time performing calculations only at desired points.
--gcc 12:05, 25 May 2011 (EDT)
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
- Sinyuk, A., O. Torres, and O. Dubovik (2003), Combined use of satellite and surface observations to infer the imaginary part of the refractive index of Saharan dust, Geophys. Res. Lett., 30(2), 1081.