GEOS-IT

GEOS-IT (Goddard Earth Observing System Instrument Team) is a data assimilation system that runs in a consistent and near-real-time framework and provides specialized meteorological data products by NASA's Global Modeling and Assimilation Office (GMAO), enabling various NASA authorized instrument teams to more accurately interpret and utilize data from Earth-observing satellites and instruments. GEOS-IT now provides dual lat-lon and cubed-sphere versions with the spatial resolution of 0.5° latitude and 0.625° longitude and C180. At the end of 2021, GEOS-IT replaced the GEOS-FPIT dataset to take advantage of enhancements in the newer GEOS-5.29.4 system release. Like GEOS-FPIT, the time period for GEOS-IT covers from 1998 to the present, which includes the active years of the NASA EOS instruments supported by GMAO.

Overview

As the successor to the GEOS-FPIT dataset, GEOS-IT is a stable meteorological dataset designed for NASA's instrument teams. This section serves as a foundational guide to the GEOS-IT data products.

GEOS-IT Product Timeline

Timeline	Description
May-July 2021	Tested 2018 data and validated
September 2021	Began production
January 2022	Data release of 2018 -> near-real-time production
Early 2022	Release of 1998 -> 2007 and 2008 -> 2017
September 2022	All data produced and released up to real time.

--Bill Z. (talk) Aug 12, 2025 (UTC)

GEOS-IT File Specification Parameter Table

According to GEOS-IT File Specification Parameter Table, the following table shows the parameters for each GEOS-IT file collection. The short name for ordering from the GES DISC, along with its description, is also included.

Collection Name	Short Name for Ordering	Description
asm_const_0hr_glo_C180x180x6_slv	GEOSIT_ASM_C0_C_SLV	Constant Fields
asm_const_0hr_glo_L576x361_slv	GEOSIT_ASM_C0_L_SLV	Constant Fields
adg_tavg_3hr_glo_L576x361_slv	GEOSIT_ADG_T3_L_SLV	Extended Aerosol Diagnostics
aer_inst_3hr_glo_L576x361_v72	GEOSIT_AER_I3_L_V72	Aerosol Diagnostics
aer_tavg_3hr_glo_L576x361_slv	GEOSIT_AER_T3_L_SLV	Primary Aerosol Diagnostics
asm_inst_1hr_glo_L576x361_slv	GEOSIT_ASM_I1_L_SLV	State
asm_inst_3hr_glo_L576x361_p42	GEOSIT_ASM_I3_L_P42	State On Pressure Levels
asm_inst_3hr_glo_L576x361_v72	GEOSIT_ASM_I3_L_V72	State On Native Levels
asm_tavg_3hr_glo_L576x361_v72	GEOSIT_ASM_T3_L_V72	Assimilated State On Native Levels
chm_inst_3hr_glo_L576x361_v72	GEOSIT_CHM_I3_L_V72	Chemistry Diagnostics
chm_tavg_3hr_glo_L576x361_slv	GEOSIT_CHM_T3_L_SLV	Chemistry Diagnostics
cld_tavg_3hr_glo_L576x361_v72	GEOSIT_CLD_T3_L_V72	Cloud Diagnostics
flx_tavg_1hr_glo_L576x361_slv	GEOSIT_FLX_T1_L_SLV	Surface Flux Diagnostics
lfo_inst_1hr_glo_L576x361_slv	GEOSIT_LFO_I1_L_SLV	Land Surface Forcing
lfo_tavg_1hr_glo_L576x361_slv	GEOSIT_LFO_T1_L_SLV	Land Surface Forcing
lnd_tavg_1hr_glo_L576x361_slv	GEOSIT_LND_T1_L_SLV	Land Surface Diagnostics
mst_tavg_3hr_glo_L576x361_v72	GEOSIT_MST_T3_L_V72	Moist Processes Diagnostics
mst_tavg_3hr_glo_L576x361_v73	GEOSIT_MST_T3_L_V73	Moist Processes Diagnostics At Edges
nav_tavg_3hr_glo_L576x361_v72	GEOSIT_NAV_T3_L_V72	Vertical Coordinate Navigation
nav_tavg_3hr_glo_L576x361_v73	GEOSIT_NAV_T3_L_V73	Vertical Coordinate Navigation At Edges
ocn_tavg_1hr_glo_L576x361_slv	GEOSIT_OCN_T1_L_SLV	Ocean Related Variables
rad_tavg_1hr_glo_L576x361_slv	GEOSIT_RAD_T1_L_SLV	Radiation Diagnostics
rad_tavg_3hr_glo_L576x361_v72	GEOSIT_RAD_T3_L_V72	Radiation Diagnostics
slv_tavg_1hr_glo_L576x361_slv	GEOSIT_SLV_T1_L_SLV	Single Level Diagnostics
tdt_tavg_3hr_glo_L576x361_v72	GEOSIT_TDT_T3_L_V72	Temperature Tendencies
trb_tavg_3hr_glo_L576x361_v73	GEOSIT_TRB_T3_L_V73	Turbulence Diagnostics At Edges
adg_tavg_3hr_glo_C180x180x6_slv	GEOSIT_ADG_T3_C_SLV	Extended Aerosol Diagnostics
aer_inst_3hr_glo_C180x180x6_v72	GEOSIT_AER_I3_C_V72	Aerosol Diagnostics
aer_tavg_3hr_glo_C180x180x6_slv	GEOSIT_AER_T3_C_SLV	Primary Aerosol Diagnostics
asm_inst_1hr_glo_C180x180x6_slv	GEOSIT_ASM_I1_C_SLV	State
asm_inst_3hr_glo_C180x180x6_v72	GEOSIT_ASM_I3_C_V72	State On Native Levels
asm_tavg_3hr_glo_C180x180x6_v72	GEOSIT_ASM_T3_C_V72	Assimilated State On Native Levels
chm_inst_3hr_glo_C180x180x6_v72	GEOSIT_CHM_I3_C_V72	Chemistry Diagnostics
chm_tavg_3hr_glo_C180x180x6_slv	GEOSIT_CHM_T3_C_SLV	Chemistry Diagnostics
cld_tavg_3hr_glo_C180x180x6_v72	GEOSIT_CLD_T3_C_V72	Cloud Diagnostics
flx_tavg_1hr_glo_C180x180x6_slv	GEOSIT_FLX_T1_C_SLV	Surface Flux Diagnostics
lfo_inst_1hr_glo_C180x180x6_slv	GEOSIT_LFO_I1_C_SLV	Land Surface Forcing
lfo_tavg_1hr_glo_C180x180x6_slv	GEOSIT_LFO_T1_C_SLV	Land Surface Forcing
lnd_tavg_1hr_glo_C180x180x6_slv	GEOSIT_LND_T1_C_SLV	Land Surface Diagnostics
mst_tavg_3hr_glo_C180x180x6_v72	GEOSIT_MST_T3_C_V72	Moist Processes Diagnostics
mst_tavg_3hr_glo_C180x180x6_v73	GEOSIT_MST_T3_C_V73	Moist Processes Diagnostics At Edges
nav_tavg_3hr_glo_C180x180x6_v72	GEOSIT_NAV_T3_C_V72	Vertical Coordinate Navigation
nav_tavg_3hr_glo_C180x180x6_v73	GEOSIT_NAV_T3_C_V73	Vertical Coordinate Navigation At Edges
ocn_tavg_1hr_glo_C180x180x6_slv	GEOSIT_OCN_T1_C_SLV	Ocean Related Variables
rad_tavg_1hr_glo_C180x180x6_slv	GEOSIT_RAD_T1_C_SLV	Radiation Diagnostics
rad_tavg_3hr_glo_C180x180x6_v72	GEOSIT_RAD_T3_C_V72	Radiation Diagnostics
slv_tavg_1hr_glo_C180x180x6_slv	GEOSIT_SLV_T1_C_SLV	Single Level Diagnostics
tdt_tavg_3hr_glo_C180x180x6_v72	GEOSIT_TDT_T3_C_V72	Temperature Tendencies
trb_tavg_3hr_glo_C180x180x6_v73	GEOSIT_TRB_T3_C_V73	Turbulence Diagnostics At Edges

Acknowledge the source of GEOS-IT data in your publications

If your GEOS-Chem research depends on the GEOS-IT meteorological data products, please consider adding an acknowledgment to your citations, such as:

The GEOS-IT data used in this study/project have been provided by the Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center.

--Bill Z. (talk) Aug 13, 2025 (UTC)

Developers

The following table credits the various individuals who have assisted with the development of the GEOS-IT met data product and its incorporation into GEOS-Chem:

Developers	Feature
NASA/GMAO	Creation of GEOS-IT assimilated meteorological data product
Bob Yantosca (GCST)	Creation of GEOS-IT data processing software
GEOS-Chem Support Team	Making GEOS-Chem compatible with GEOS-IT met data

--Bill Z. (talk) Aug 12, 2025 (UTC)

GEOS-IT grid structure

This section describes the horizontal and vertical grids used by the GEOS-FPIT data products.

Input grids

From the GEOS-5 FPIT Product Details, Version 1.4:

Data Type	Source	Active/Passive	Time Period Used
AEROSOLS Terra & Aqua AOD	NCEP GDAS	Active	8/18/2011 - Present
TEMPERATURE Radiosonde, Aircraft, Dropsonde, Drifting Buoy Surface Marine, Splash Level Sea Surface	NCEP GDAS NCEP GDAS NCEP GDAS	Active Active Active	8/18/2011 - Present 8/18/2011 - Present 8/18/2011 - Present
PRESSURE METAR, Land Station, Splash Level Radiosonde Station, Marine Surface, Drifting Buoy	NCEP GDAS NCEP GDAS	Active Active	8/18/2011 - Present 8/18/2011 - Present
RADIANCES Aqua AIRS & AMSU-A AMSU-A, HIRS4, ATMS SSM/IS, AMSR-E, AMSU-B, HIRS3, GOES13 MHS,IASI	NOAA SERVER NCEP GDAS NCEP GDAS NCEP GDAS	Active Active Passive Active	8/18/2011 - Present 8/18/2011 - Present 8/18/2011 - Present 8/18/2011 - Present
WINDS Radiosonde, PIBAL, Wind Profiler, NEXRAD Aircraft, Dropsonde, Surface Marine Atlas Buoy, WINDSAT, ASCAT IR/VIS Cloud Drift, Water Vapor, PILOT Japanese Profiler	NCEP GDAS NCEP GDAS NCEP GDAS NCEP GDAS NCEP GDAS	Active Active Active Active Passive	8/18/2011 - Present 8/18/2011 - Present 8/18/2011 - Present 8/18/2011 - Present 8/18/2011 - Present
MOISTURE Radiosonde, Surface Marine, Splash Level, TMI Rain Rate	NCEP GDAS	Active	8/18/2011 - Present
GPS RADIO OCCULTATION GRACE-A, TerraSAR-X, METOP-A COSMIC-1, 4, 5, 6, C/NOFS CORISS	NCEP GDAS NCEP GDAS	Active Active	8/18/2011 - Present 8/18/2011 - Present
OZONE SBUV,OMI	NCEP GDAS	Active	8/18/2011 - Present

Output Product Highlights

1. 3-D collections are on a 5/8 x 1/2 degree lon-lat horizontal grid
2. Near-real-time data in 3-D and 2-D
3. 42 pressure levels or 72 model grid layers
4. 2-D data every hour, 3-D data every 3 hours

--Bill Z. (talk) Aug 18, 2025 (UTC)

GEOS-IT File Naming Convention

Standard names

The assimilated GEOS-5 GEOS-IT products are available in both 2-D and 3-D versions. The following are the breakdowns of the standard full name for each. The standard format consists of seven parts.

       general-prefix.file-collection.system-version.timestamp.file-version.nc4

The node fields, which vary from file to file, are defined as follows:

general-prefix

For mainstream GEOS-IT data, the following prefixes are used:

• GEOS.it.asm: GEOS.it stands for GEOS for Instrument Teams, asm specifies the file type, which in this case is Assimilation.

file-collection

Collection names are of the form group_freq_interval_glo_dimension_vertical-Grid, where the attributes are:

• group: A three-letter mnemonic for the type of fields in the collection. It is a lowercase version of the group designation used in the ESDT name, as listed in the next section.
• freq: time-independent (const), instantaneous (inst), or time-average (tavg)
• interval: Time interval can be 1hr (1 hour), 3hr (3 hours) or 0hr (0 hour for const file).
• glo: indicates a global domain
• dimension: refers to a latitude-longitude grid with dimensions of 576x361 (L576x361), or a cubed-sphere grid with dimensions of 180x180x6 (C180x180x6).
• vertical-grid: slv (single level), v72 (72 vertical layers), or v73 (73 vertical layers).

system-version

This is the system version that produced the data. It is GEOS5294 (GEOS5.29.4) in this case.

timestamp

This node defines the date and time associated with the data in the file. It has the form yyyy-mm-ddThhmm

• yyyy - year string (e.g. , 2002)
• mm - month string (e.g.., 09 for September)
• dd - day of the month string
• hh - hour string
• mm - minute string

file-version

This is the version number of the file. Under normal conditions, it will be V01.

nc4

Denotes that the data is being saved in a netCDF-4 file.

EXAMPLE:

       GEOS.it.asm.asm_inst_3hr_glo_L576x361_v72.GEOS5294.2025-08-18T0000.V01.nc4

• GEOS.it.asm: GEOS-IT Assimilation
• asm_inst_3hr_glo_L576x361_v72: Assimilated state variables instantaneous 3-hour data in the global domain with 2-D dimension of 576x361 points with 72 native model levels.
• GEOS5294: Produced version id is GEOS5.29.4.

--Bill Z. (talk) Aug 18, 2025 (UTC)

ESDT names

As required by the EOSDIS system, all GEOS-5 FP products are identified by a relatively short ESDT name. While GEOS-5 FP products are not currently distributed from the GES DISC, we have retained the ESDT designations for assimilation products. This name, also known as the ShortName, is a short handle for users to access and order data products. It takes the form: DFPTFHVGGG, where:

1. T: Time Description:
   • I = Instantaneous
   • T = Time-averaged
   • C = Time-independent
2. F: Frequency
   • 0 = Time-independent
   • 1 = Hourly
   • 3 = 3-Hourly
3. H: Horizontal Resolution
   • N = Native
4. V: Vertical Location
   • X = Two-dimensional
   • P = Pressure
   • V = model layer center
   • E = model layer edge
5. GGG: Group
   • ASM = assimilated state variables (from the IAU corrector, see Appendix A)
   • TDT = tendencies of temperature
   • UDT = tendencies of eastward and northward wind components
   • QDT = tendencies of specific humidity
   • ODT = tendencies of ozone
   • LND = land surface variables
   • FLX = surface turbulent fluxes and related quantities
   • MST = moist processes
   • CLD = cloud-related quantities
   • RAD = radiation
   • TRB = turbulence
   • SLV = single level
   • INT = vertical integrals
   • CHM = chemistry forcing
   • AER = aerosol diagnostics
   • ADG = aerosol diagnostics (extended)
   • LSF = large-scale flux
   • OCN = ocean
   • LFO = land-surface forcing
   • NAV = navigation
   • CTM = Chemical Transport Model

--Bill Z. (talk) Aug 19, 2025 (UTC)

GEOS-IT data file collections

The following table shows only those GEOS-IT file collections that are required for GEOS-Chem.

NOTES:

• GEOS-IT on lat-lon Grid
  • Native Horizontal Grid: 0.625&deg longitude x 0.5&deg latitude (576 x 361 grid boxes)
  • Horizontal Arrays: Have dimensions 576 (lon) x 361 (lat)
  • For files containing 3D data:
    • Horizontal arrays have dimensions 576 x 361 x 72 (or 73) levels.
    • Level 1 corresponds to the top of the atmosphere
    • Level 72 (or 73) corresponds to the surface.
  • Longitudes increase eastward, starting at −180&deg.
  • Latitudes increase northward, starting at −90&deg.

• GEOS-IT on Cubed-Sphere Grid
  • Native Horizontal Grid: Equidistant gnomonic cubed-sphere grid (C180)
  • Horizontal Arrays: Have dimensions 180×180×6 faces.
  • For files containing 3D data:
    • Horizontal arrays have dimensions 576 x 361 x 72 (or 73) levels.
    • Level 1 corresponds to the top of the atmosphere
    • Level 72 (or 73) corresponds to the surface.
  • The grid is organized by face, with each face having 180x180 grid cells.

File Collection Name	GEOS-IT ESDT (aka "Shortname")	Description	Times	Approx daily size (MB)
asm_const_0hr_glo_L576x361_slv	GEOSIT_ASM_C0_L_SLV	Constant fields	Time-invariant	~1
asm_inst_3hr_glo_L576x361_v72	GEOSIT_ASM_I3_L_V72	State On Native Levels	Instantaneous values every 3 hours	~316
asm_tavg_3hr_glo_L576x361_v72	GEOSIT_ASM_T3_L_V72	Assimilated State On Native Levels	3-hour time-averaged values	~306
chm_tavg_3hr_glo_L576x361_slv	GEOSIT_CHM_T3_L_SLV	Chemistry diagnostics	3-hour time-averaged values	~3
cld_tavg_3hr_glo_L576x361_v72	GEOSIT_CLD_T3_L_V72	Cloud Diagnostics	3-hour time-averaged values	~100
flx_tavg_1hr_glo_L576x361_slv	GEOSIT_FLX_T1_L_SLV	Surface Flux Diagnostics	1-hour time-averaged values	~17
lfo_tavg_1hr_glo_L576x361_slv	GEOSIT_LFO_T1_L_SLV	Land Surface Forcing	1-hour time-averaged values	~3
lnd_tavg_1hr_glo_L576x361_slv	GEOSIT_LND_T1_L_SLV	Land Surface Diagnostics	1-hour time-averaged values	~9
mst_tavg_3hr_glo_L576x361_v72	GEOSIT_MST_T3_L_V72	Moist Processes Diagnostics	3-hour time-averaged values	~37
mst_tavg_3hr_glo_L576x361_v73	GEOSIT_MST_T3_L_V73	Moist Processes Diagnostics At Edges	3-hour time-averaged values	~29
rad_tavg_1hr_glo_L576x361_slv	GEOSIT_RAD_T1_L_SLV	Radiation Diagnostics	1-hour time-averaged values	~10
rad_tavg_3hr_glo_L576x361_v72	GEOSIT_RAD_T3_L_V72	Radiation Diagnostics	3-hour time-averaged values	~113
slv_tavg_1hr_glo_L576x361_slv	GEOSIT_SLV_T1_L_SLV	Single Level Diagnostics	1-hour time-averaged values	~17
asm_const_0hr_glo_C180x180x6_slv	GEOSIT_ASM_C0_C_SLV	Constant fields	Time-invariant	~7
asm_inst_3hr_glo_C180x180x6_v72	GEOSIT_ASM_I3_C_V72	State On Native Levels	Instantaneous values every 3 hours	~329
asm_tavg_3hr_glo_C180x180x6_v72	GEOSIT_ASM_T3_C_V72	Assimilated State On Native Levels	3-hour time-averaged values	~320
cld_tavg_3hr_glo_C180x180x6_v72	GEOSIT_CLD_T3_C_V72	Cloud Diagnostics	3-hour time-averaged values	~104
ctm_inst_1hr_glo_C180x180x6_v72		Chemical Transport Model	Instantaneous values for every 1 hour	~42
ctm_tavg_1hr_glo_C180x180x6_v72		Chemical Transport Model	1-hour time-averaged values	~188
flx_tavg_1hr_glo_C180x180x6_slv	GEOSIT_FLX_T1_C_SLV	Surface Flux Diagnostics	1-hour time-averaged values	~23
lnd_tavg_1hr_glo_C180x180x6_slv	GEOSIT_LND_T1_C_SLV	Land Surface Diagnostics	1-hour time-averaged values	~16
mst_tavg_3hr_glo_C180x180x6_v72	GEOSIT_MST_T3_C_V72	Moist Processes Diagnostics	1-hour time-averaged values	~44
rad_tavg_1hr_glo_C180x180x6_slv	GEOSIT_RAD_T1_C_SLV	Radiation Diagnostics	1-hour time-averaged values	~16
rad_tavg_3hr_glo_C180x180x6_v72	GEOSIT_RAD_T3_C_V72	Radiation Diagnostics	3-hour time-averaged values	~123
slv_tavg_1hr_glo_C180x180x6_slv	GEOSIT_SLV_T1_C_SLV	Single Level Diagnostics	1-hour time-averaged values	~23

As described above, the full file name for the GEOS-FP data products takes the form:

GEOS.it.asm.COLLECTION.GEOS-VERSION.YYYYMMDDTTTT.FILE-VERSION.nc4

where

1. COLLECTION is the collection name (i.e. one of the entries in the first column of the above table)
2. GEOS-VERSION is the system version that produced the data.
3. YYYYMMDDThhmm is the UTC date (year/month/day+T+hour/minute)
4. FILE-VERSION is normally V01.

--Bill Z. (talk) Aug 20, 2025 (UTC)

GEOS-IT time archiving

Raw data

The GEOS-IT raw data are archived/averaged at the following times:

Collections	Description	Timestamps
asm_const_0hr_glo_L576x361_slv asm_const_0hr_glo_C180x180x6_slv	Time-invariant data	N/A
asm_inst_3hr_glo_L576x361_v72 asm_inst_3hr_glo_C180x180x6_v72<	Instantaneous (snapshot) data, every 3 hours	00:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00, 21:00 UTC
ctm_inst_1hr_glo_C180x180x6_v72	Instantaneous (snapshot) data, every 1 hour	00:00, 01:00, 03:00 ... 23:00 UTC
flx_tavg_1hr_glo_L576x361_slv lfo_tavg_1hr_glo_L576x361_slv lnd_tavg_1hr_glo_L576x361_slv rad_tavg_1hr_glo_L576x361_slv slv_tavg_1hr_glo_L576x361_slv flx_tavg_1hr_glo_C180x180x6_slv lnd_tavg_1hr_glo_C180x180x6_slv rad_tavg_1hr_glo_C180x180x6_slv slv_tavg_1hr_glo_C180x180x6_slv ctm_tavg_1hr_glo_C180x180x6_v72	1-hour time-averaged data	00:30, 01:30, 02:30 ... 23:30 UTC These represent the centers of each 1-hr time-averaging bin
asm_tavg_3hr_glo_L576x361_v72 chm_tavg_3hr_glo_L576x361_slv cld_tavg_3hr_glo_L576x361_v72 mst_tavg_3hr_glo_L576x361_v72 mst_tavg_3hr_glo_L576x361_v73 rad_tavg_3hr_glo_L576x361_v72 asm_tavg_3hr_glo_C180x180x6_v72 cld_tavg_3hr_glo_C180x180x6_v72 mst_tavg_3hr_glo_C180x180x6_v72 rad_tavg_3hr_glo_C180x180x6_v72	3-hour time-averaged data	01:30, 04:30, 07:30, 10:30, 13:30, 16:30, 19:30, 22:30 UTC These represent the centers of each 3-hr time-averaging bin

Processed data

The processed GEOS-IT data for GEOS-Chem shall keep the same temporal resolution as the GEOS-IT raw data. To prevent file sizes from becoming larger than 2GB (i.e. the maximum netCDF-3 file size), we split the regridded GEOS-IT data among the following file types:

Filenames	Description	Timestamps
GEOSIT.19980101.CN.{RES}.nc	Time-invariant data	For convenience, we assign a file timestamp of 1998/01/01 at 00:00 GMT.
GEOSIT.YYYYMMDD.A1.{RES}.nc	1-hour time-averaged data	00:30, 01:30, 02:30 ... 23:30 UTC These represent the centers of each 1-hr time-averaging bin
GEOSIT.YYYYMMDD.A3cld.{RES}.nc GEOSIT.YYYYMMDD.A3dyn.{RES}.nc GEOSIT.YYYYMMDD.A3mstC.{RES}.nc GEOSIT.YYYYMMDD.A3mstE.{RES}.nc	3-hour time-averaged data	01:30, 04:30, 07:30, 10:30, 13:30, 16:30, 19:30, 22:30 UTC These represent the centers of each 3-hr time-averaging bin
GEOSIT.YYYYMMDD.I3.{RES}.nc	3-hour time-averaged data	00:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00, 21:00 UTC

In the filenames above, the {RES} tag indicates the horizontal resolution of the file. Possible values are:

{RES}	Description
4x5	GEOS-Chem 4° x 5° global grid
2x25	GEOS-Chem 2° x 2.5° global grid
05x0625	GEOS-Chem 0.5° x 0.625° global grid
05x0625.EU	GEOS-Chem 0.5° x 0.625° Europe nested grid
05x0625.NA	GEOS-Chem 0.5° x 0.625° North America nested grid

The A1 and A3 files use the following bins for time-averaging. The file timestamps in the data files indicate the center of the time-averaging bins.

NOTE: GEOS-IT uses the same timing scheme as the data marked in the plot as "GEOS-FP". (We will eventually update the image below.)

--Bill Z. (talk) Aug 20, 2025 (UTC)

References

1. Auer, B. 2021: CS Description. 6 pp, available from https://gmao.gsfc.nasa.gov/media/gmao_products/IqPeIBhIWLGrweILfVPj9Vmdoc/CS_Description_c180_v1_1c8ute6qgsxi3z7fho0kwjdyp.pdf.
2. Akkraoui, A., Lucchesi, R., Partyka, G., Pawson, S. 2020: Planning for GEOS-IT. GMAO Office, 24 pp, available from https://ntrs.nasa.gov/api/citations/20205005789/downloads/plans_4_geos-it_final.pptx.pdf.
3. Conaty, A., Akkraoui, A.E., Lucchesi, R., Bosilovich, M. 2021: Status Update on GMAO’s Upcoming GEOS-IT and GEOS R21C Retrospective Analyses. GMAO Office, 15 pp, available from https://ntrs.nasa.gov/api/citations/20210023766/downloads/ceres_14oct2021.pdf.
4. Collow, A., Silva, A.D., Colarco, P., Buchard, V., Castellanos, P., Govindaraju, R., Akkraoui, A.E., Lucchesi, R. 2024: The Representation of Aerosols in GMAO’s Newest Reanalyses. NTRS - NASA Technical Reports Server, available from https://ntrs.nasa.gov/citations/20240013394.
5. Collow, A., V. Buchard, M. Chin, P. Colarco, A. Darmenov, and A. da Silva, 2022: Supplemental Documentation for GEOS Aerosol Products. GMAO Office Note No. 22 (Version 1.0), 8 pp, available from http://gmao.gsfc.nasa.gov/pubs/office_notes.
6. Lucchesi, R., 2015: File Specification for GEOS-5 FP-IT. GMAO Office Note No. 2 (Version 1.3), 60 pp, available from http://gmao.gsfc.nasa.gov/pubs/office_notes.
7. GEOS-IT Collections and Filenames from GMAO
8. GEOS-IT_File_Specification_Parameter_Table.pdf from GMAO
9. GEOS Near-Real-Time Data Products from GMAO
10. GEOS-IT-Update-2021-06-30.docx from GMAO

--Bill Z. (talk) Aug 20, 2025 (UTC)