GEOS-CF ana tavg1hr v2: Goddard Earth Observing System Composition Forecast

Dataset Availability

2025-08-04T00:00:00Z–2026-06-20T08:00:00Z

Dataset Producer

NASA / GMAO

Earth Engine Snippet

ee.ImageCollection("NASA/GEOS-CF/v2/ana/tavg1hr")

Tags

atmosphere

composition

forecast

geos

geos-cf

gmao

nasa

Description

This dataset contains meteorological analysis (ana) of time-average one hour data (tavg1hr). It is built by merging the original GEOS-CF collections chm_tavg_1hr_glo_L1440x721_slv, met_tavg_1hr_glo_L1440x721_slv, and xgc_tavg_1hr_glo_L1440x721_slv. The Goddard Earth Observing System Composition Forecast (GEOS-CF) system is a global constituent prediction system from NASA's Global Modeling and Assimilation Office(GMAO).

GEOS-CF offers a tool for atmospheric chemistry research, with the goal to supplement NASA's broad range of space-based and in-situ observations. GEOS-CF expands on the GEOS weather and aerosol modeling system by introducing the GEOS-Chem chemistry module to provide hindcasts and 5-days forecasts of atmospheric constituents including ozone (O₃), carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), coarse particulate matter (PM₁₀), and fine particulate matter (PM_2.5). The chemistry module integrated in GEOS-CF is identical to the offline GEOS-Chem model and readily benefits from the innovations provided by the GEOS-Chem community. Outputs are provided globally at 0.25° horizontal resolution.

In October 2025, a major update to the GEOS-CF system was introduced as GEOS-CF v2. This change included updates to the GEOS atmospheric general circulation model and the GEOS-Chem chemical model, replaying meteorology to GEOS IT, direct assimilation of stratospheric profiles and column ozone from NASA Aura OMI and MLS instruments, and updates to the anthropogenic emission source. Evaluation of these updates is ongoing; results will be added into this description as they become available. Preliminary results suggest that, in relation to GEOS-CF v1, GEOS-CF v2 dramatically improves the representation of PM_2.5 and SO₂ near the surface. While representations of O₃ and NO₂ are generally improved throughout most of the atmospheric column, representation of near-surface concentrations (i.e., at atmospheric levels directly relevant to air quality) may be degraded comapred to v1.

Users of GEOS-CF are encouraged to treat outputs from the original system (v1) and the new system (v2) separately in their analysis, due to the extensive changes between the systems.

Bands

Bands

Pixel size: 27750 meters (all bands)

Name	Units	Pixel Size	Description
ACET	Mol fraction	27750 meters	Acetone (CH3C(O)CH3, MW=58.09 g mol-1) mole fraction in dry air
ALD2	Mol fraction	27750 meters	Acetaldehyde (CH3CHO, MW=44.06 g mol-1) mole fraction in dry air
ALK4	Mol fraction	27750 meters	Lumped >= C4 Alkanes (MW=58.12 g mol-1) mole fraction in dry air
AOD550_BC	Dimensionless	27750 meters	Aerosol optical depth at 550 nm of black carbon aerosols
AOD550_DUST	Dimensionless	27750 meters	Aerosol optical depth at 550 nm of dust aerosols
AOD550_OC	Dimensionless	27750 meters	Aerosol optical depth at 550 nm of organic aerosols
AOD550_PSC	Dimensionless	27750 meters	Aerosol optical depth at 550 nm of polar stratospheric cloud
AOD550_SLA	Dimensionless	27750 meters	Aerosol optical depth at 550 nm of stratospheric liquid aerosols
AOD550_SNA	Dimensionless	27750 meters	Aerosol optical depth at 550 nm of sulfate-nitrate-ammonium aerosols
AOD550_SS	Dimensionless	27750 meters	Aerosol optical depth at 550 nm of sea salt aerosols
BCPI	Mol fraction	27750 meters	Hydrophilic black carbon aerosol (C, MW=12.01 g mol-1) mole fraction in dry air
BCPO	Mol fraction	27750 meters	Hydrophobic black carbon aerosol (C, MW=12.01 g mol-1) mole fraction in dry air
BENZ	Mol fraction	27750 meters	Benzene (C6H6, MW=78.12 g mol-1) mole fraction in dry air
C2H6	Mol fraction	27750 meters	Ethane (C2H6, MW=30.08 g mol-1) mole fraction in dry air
C3H8	Mol fraction	27750 meters	Propane (C3H8, MW=44.11 g mol-1) mole fraction in dry air
CLDTT	Dimensionless	27750 meters	Total cloud area fraction
CO	Mol fraction	27750 meters	Carbon monoxide (CO, MW=28.01 g mol-1) mole fraction in dry air
COSZ	Dimensionless	27750 meters	Cosine of the solar zenith angle
DST1	Mol fraction	27750 meters	Dust aerosol; Reff = 0.7 microns (MW=29.0 g mol-1) mole fraction in dry air
DST2	Mol fraction	27750 meters	Dust aerosol; Reff = 1.4 microns (MW=29.0 g mol-1) mole fraction in dry air
DST3	Mol fraction	27750 meters	Dust aerosol; Reff = 2.4 microns (MW=29.0 g mol-1) mole fraction in dry air
DST4	Mol fraction	27750 meters	Dust aerosol; Reff = 4.5 microns (MW=29.0 g mol-1) mole fraction in dry air
EOH	Mol fraction	27750 meters	Ethanol (C2H5OH, MW=46.07 g mol-1) mole fraction in dry air
H2O2	Mol fraction	27750 meters	Hydrogen peroxide (H2O2, MW=34.02 g mol-1) mole fraction in dry air
HCHO	Mol fraction	27750 meters	Formaldehyde (CH2O, MW=30.03 g mol-1) mole fraction in dry air
HNO3	Mol fraction	27750 meters	Nitric acid (HNO3, MW=63.01 g mol-1) mole fraction in dry air
HNO4	Mol fraction	27750 meters	Peroxynitric acid (HNO4, MW=79.01 g mol-1) mole fraction in dry air
ISOP	Mol fraction	27750 meters	Isoprene (CH2=C(CH3)CH=CH2, MW=68.13 g mol-1) mole fraction in dry air
MACR	Mol fraction	27750 meters	Methacrolein (CH2=C(CH3)CHO, MW=70.1 g mol-1) mole fraction in dry air
MEK	Mol fraction	27750 meters	Methyl Ethyl Ketone (RC(O)R, MW=72.11 g mol-1) mole fraction in dry air
MVK	Mol fraction	27750 meters	Methyl vinyl ketone (CH2=CHC(=O)CH3, MW=70.09 g mol-1) mole fraction in dry air
N2O5	Mol fraction	27750 meters	Dinitrogen pentoxide (N2O5, MW=108.02 g mol-1) mole fraction in dry air
NH3	Mol fraction	27750 meters	Ammonia (NH3, MW=17.04 g mol-1) mole fraction in dry air
NH4	Mol fraction	27750 meters	Ammonium (NH4, MW=18.05 g mol-1) mole fraction in dry air
NIT	Mol fraction	27750 meters	Inorganic nitrates (MW=62.01 g mol-1) mole fraction in dry air
NO	Mol fraction	27750 meters	Nitrogen oxide (NO, MW=30.01 g mol-1) mole fraction in dry air
NO2	Mol fraction	27750 meters	Nitrogen dioxide (NO2, MW=46.01 g mol-1) mole fraction in dry air
NOy	Mol fraction	27750 meters	Total reactive oxidized nitrogen (gas+aerosol) mole fraction in dry air
O3	Mol fraction	27750 meters	Ozone (O3, MW=48.0 g mol-1) mole fraction in dry air
OCPI	Mol fraction	27750 meters	Hydrophilic organic carbon aerosol (MW=12.01 g mol-1) mole fraction in dry air
OCPO	Mol fraction	27750 meters	Hydrophobic organic carbon aerosol (MW=12.01 g mol-1) mole fraction in dry air
PAN	Mol fraction	27750 meters	Peroxyacetyl nitrate (CH3C(O)OONO2, MW=121.06 g mol-1) mole fraction in dry air
PBLCol_NO2	1.0e15 molecules/cm^2	27750 meters	Boundary layer column density of nitrogen dioxide (MW=46.01 g mol-1)
PBLCol_O3	1.0e15 molecules/cm^2	27750 meters	Boundary layer column density of ozone (MW=48.0 g mol-1)
PBLCol_SO2	1.0e15 molecules/cm^2	27750 meters	Boundary layer column density of sulfur dioxide (MW=64.04 g mol-1)
PHIS	m^2/s^2	27750 meters	Surface geopotential height
PM10_RH35	μg/m³	27750 meters	Particulate matter with diameter less than 10 um mass at RH 35% (includes water) mass concentration in dry air
PM25_RH35	μg/m³	27750 meters	Particulate matter with diameter less than 2.5 um mass at RH 35% (includes water) mass concentration in dry air
PM25bc_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from black carbon mass concentration in dry air
PM25du_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from dust mass concentration in dry air
PM25nit_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from nitrate (includes water) mass concentration in dry air
PM25nh4_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from ammonium (includes water) mass concentration in dry air
PM25oc_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from primary organic aerosols (includes water) mass concentration in dry air
PM25soa_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from secondary organic aerosols (includes water) mass concentration in dry air
PM25ss_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from sea salt aerosols (includes water) mass concentration in dry air
PM25su_RH35	μg/m³	27750 meters	PM2.5 mass at RH 35% from sulfates (includes water) mass concentration in dry air
PRPE	Mol fraction	27750 meters	Lumped >= C3 alkenes (C3H6, MW=42.09 g mol-1) mole fraction in dry air
PS	Pa	27750 meters	Surface pressure
Q	Mass fraction	27750 meters	Specific humidity
RCHO	Mol fraction	27750 meters	Lumped aldehyde >= C3 (CH3CH2CHO, MW=58.09 g mol-1) mole fraction in dry air
RH	Dimensionless	27750 meters	Relative humidity after moist
SALA	Mol fraction	27750 meters	Fine (0.01-0.05 microns) sea salt aerosol (MW=31.4 g mol-1) mole fraction in dry air
SALC	Mol fraction	27750 meters	Coarse (0.5-8 microns) sea salt aerosol (MW=31.4 g mol-1) mole fraction in dry air
SLP	Pa	27750 meters	Sea level pressure
SO2	Mol fraction	27750 meters	Sulfur dioxide (SO2, MW=64.04 g mol-1) mole fraction in dry air
SOAP	Mol fraction	27750 meters	SOA Precursor - lumped species for simplified SOA parameterization (MW=150.0 g mol-1) mole fraction in dry air
SOAS	Mol fraction	27750 meters	SOA Simple - simplified non-volatile SOA parameterization (MW=150.0 g mol-1) mole fraction in dry air
T	K	27750 meters	Air temperature
TOLU	Mol fraction	27750 meters	Toluene (C7H8, MW=92.15 g mol-1) mole fraction in dry air
TotCol_BrO	1.0e15 molecules/cm^2	27750 meters	Total column density of bromine monoxide (MW=95.9 g mol-1)
TotCol_CO	1.0e15 molecules/cm^2	27750 meters	Total column density of carbon monoxide (MW=28.01 g mol-1)
TotCol_IO	1.0e15 molecules/cm^2	27750 meters	Total column density of iodine monoxide (MW=206.9 g mol-1)
TotCol_NO2	1.0e15 molecules/cm^2	27750 meters	Total column density of nitrogen dioxide (MW=46.01 g mol-1)
TotCol_O3	Dobson	27750 meters	Total column density of ozone (MW=48.0 g mol-1)
TotCol_SO2	1.0e15 molecules/cm^2	27750 meters	Total column density of SO2 sulfur dioxide (MW=64.04 g mol-1)
TPREC	kg/m^2/s	27750 meters	Total precipitation
TropCol_BrO	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of bromine monoxide (MW=95.9 g mol-1)
TropCol_CO	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of carbon monoxide (MW=28.01 g mol-1)
TropCol_GLYX	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of glyoxal (MW=58.04 g mol-1)
TropCol_HCHO	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of formaldehyde (MW=30.03 g mol-1)
TropCol_HCOOH	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of formic acid (MW=46.03 g mol-1)
TropCol_IO	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of iodine monoxide (MW=206.9 g mol-1)
TropCol_ISOP	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of isoprene (MW=100.13 g mol-1)
TropCol_NH3	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of ammonia (MW=17.04 g mol-1)
TropCol_NO2	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of nitrogen dioxide (MW=46.01 g mol-1)
TropCol_O3	Dobson	27750 meters	Tropospheric column density of ozone (MW=48.0 g mol-1)
TropCol_PAN	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of peroxyacetyl nitrate (MW=121.06 g mol-1)
TropCol_SO2	1.0e15 molecules/cm^2	27750 meters	Tropospheric column density of sulfur dioxide (MW=64.04 g mol-1)
TROPPB	Pa	27750 meters	Tropopause pressure based on blended estimate
TS	K	27750 meters	Surface skin temperature
U	m/s	27750 meters	Eastward wind
V	m/s	27750 meters	Northward wind
XYLE	Mol fraction	27750 meters	Xylene (C8H10, MW=106.18 g mol-1) mole fraction in dry air
ZL	m	27750 meters	Mid layer heights
ZPBL	m	27750 meters	Planetary boundary layer height

Terms of Use

Terms of Use

Unless otherwise noted, all NASA-produced data may be used for any purpose without prior permission. For more information and exceptions visit the NASA Data & Information Policy page.

Citations

Citations:

• Keller, C. A., Knowland, K. E., Duncan, B. N., Liu, J., Anderson, D. C., Das, S., ... & Pawson, S. (2021). Description of the NASA GEOS composition forecast modeling system GEOS-CF v1.0. Journal of Advances in Modeling Earth Systems, 13(4), e2020MS002413. doi:10.1029/2020MS002413

  Knowland, K. E., Keller, C. A., Wales, P. A., Wargan, K., Coy, L., Johnson, M.S., ... & Pawson, S. (2022). NASA GEOS Composition Forecast Modeling System GEOS‐CF v1.0: Stratospheric Composition. Journal of Advances in Modeling Earth Systems, 14, e2021MS002852. doi:10.1029/2021MS002852

  Note: these citations refer to the original GEOS-CF (v1) system; citations describing the new (v2) system will be added following publication.

DOIs

• https://doi.org/10.1029/2020MS002413

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Code Editor (JavaScript)

var imageVisParamNO2 = {
  'bands': ['NO2'],
  'min': 6.96e-11,
  'max': 4.42e-8,
};

var imageVisParamT = {
  'bands': ['T'],
  'min': 220,
  'max': 320,
  'palette': ['d7191c', 'fdae61', 'ffffbf', 'abd9e9', '2c7bb6'],
};

var geosCf = ee.ImageCollection('NASA/GEOS-CF/v2/ana/tavg1hr');

Map.setCenter(100, 20, 3);

var weeklyT =
    geosCf.select('T').filterDate('2025-08-04', '2025-08-11').median();
Map.addLayer(weeklyT, imageVisParamT, 'Weekly T', false, 1);

var NO2 = ee.Image('NASA/GEOS-CF/v2/ana/tavg1hr/20250804_1230z');
Map.addLayer(NO2, imageVisParamNO2, 'NO2', true, 1);

Open in Code Editor

GEOS-CF ana tavg1hr v2: Goddard Earth Observing System Composition Forecast

This dataset contains meteorological analysis (ana) of time-average one hour data (tavg1hr). It is built by merging the original GEOS-CF collections chm_tavg_1hr_glo_L1440x721_slv, met_tavg_1hr_glo_L1440x721_slv, and xgc_tavg_1hr_glo_L1440x721_slv. The Goddard Earth Observing System Composition Forecast (GEOS-CF) system is a global constituent prediction system from NASA's Global Modeling and Assimilation Office(GMAO). GEOS-CF offers a …

NASA/GEOS-CF/v2/ana/tavg1hr, atmosphere,composition,forecast,geos,geos-cf,gmao,nasa

2025-08-04T00:00:00Z/2026-06-20T08:00:00Z

-90 -180 90 180

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• https://doi.org/10.1029/2020MS002413
• https://doi.org/10.1029/2020MS002413