GEOS-CF fcst htf v2: Goddard Earth Observing System Composition Forecast

Dataset Availability

2025-08-04T00:00:00Z–2026-07-08T09:00:00Z

Dataset Producer

NASA / GMAO

Earth Engine Snippet

ee.ImageCollection("NASA/GEOS-CF/v2/fcst/htf")

Tags

atmosphere composition forecast geos geos-cf gmao nasa

Description

This dataset contains forecast (fcst) of high-temporal frequency data (htf) at 15 minute intervals. It is created from the original GEOS-CF collection htf_inst_15mn_glo_L1440x721_slv. Use the 'creation_time' and 'forecast_time' properties to select data of interest. 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. Please refer to the GEOS-CF Product Page for more details.

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. Representations of O₃ and NO₂ are generally improved throughout most of the atmospheric column, with and NO₂ being substantially lower in GEOS-CF v2 compared with v1. While representation of near-surface O₃ is improved compared to GEOS-CF v1, there remain high biases compared with ozone monitor data from the US Environmental Protection Agency.

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
CO	Mol fraction	27750 meters	Carbon monoxide (CO, MW = 28.01 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
O3	Mol fraction	27750 meters	Ozone (O3, MW = 48.0 g mol-1) volume mixing ratio dry air
PM25_RH35	μg/m³	27750 meters	Particulate matter with diameter below 2.5 um mass at RH 35% (includes water) mass concentration 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
U	m/s	27750 meters	Eastward wind
V	m/s	27750 meters	Northward wind

Image Properties

Image Properties

Name	Type	Description
creation_time	DOUBLE	Time of creation
forecast_time	DOUBLE	Forecast time

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 geosCf = ee.ImageCollection('NASA/GEOS-CF/v2/fcst/htf');

Map.setCenter(100, 20, 3);

var NO2 = ee.Image('NASA/GEOS-CF/v2/fcst/htf/20260101_09z-20260101_0930z');
Map.addLayer(NO2, imageVisParamNO2, 'NO2', true, 1);

Open in Code Editor

GEOS-CF fcst htf v2: Goddard Earth Observing System Composition Forecast

This dataset contains forecast (fcst) of high-temporal frequency data (htf) at 15 minute intervals. It is created from the original GEOS-CF collection htf_inst_15mn_glo_L1440x721_slv. Use the 'creation_time' and 'forecast_time' properties to select data of interest. The Goddard Earth Observing System Composition Forecast (GEOS-CF) system is a global constituent prediction system from …

NASA/GEOS-CF/v2/fcst/htf, atmosphere,composition,forecast,geos,geos-cf,gmao,nasa

2025-08-04T00:00:00Z/2026-07-08T09:00:00Z

-90 -180 90 180

Google Earth Engine

https://developers.google.com/earth-engine/datasets

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