Background
Remotely-sensed tropospheric and stratospheric constituent data will be assimilated into the Goddard Earth Observing System (GEOS) Constituent Data Assimilation System (CoDAS). This will provide global, three-dimensional gridded atmospheric composition distributions for the 2009-2018 period.
Status: In Development
Version 2 of the GEOS-Composition Forecasting (CF) system has been adapted for this reanalysis. The following constituents will be assimilated: hydrochloric acid (HCL), ozone (O3), water vapor (H2O), nitric acid (HNO3), nitrous oxide (N2O), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and nitrogen dioxide (NO2).
Based on the results of final testing, sulfur dioxide (SO2) will not be assimilated in this product. Similarly, system testing revealed that including the infrared bands in the ozone assimilation does not improve the product sufficiently to justify the additional expense.
Apart from some minor modifications to the NO2 assimilation the system is ready to commence production. Pre-production testing showed that generation of the reanalysis for 2009 to 2018 will take less than one year if split into two parallel streams.
Solution Characteristics
| Platforms and Instruments | Aura: Ozone Monitoring Instrument (OMI), Microwave Limb Sounder (MLS) |
|---|---|
| Aqua: Atmospheric Infrared Sounder (AIRS) | |
| Greenhouse Gases Observing SATellite (GOSAT): Thermal And Near infrared Sensor for carbon Observation (TANSO)- Cloud and Aerosol Imager (CAI), TANSO-Fourier Transform Spectrometer (FTS) | |
| International Space Station (ISS): SAGE III | |
| Orbiting Carbon Observatory-2 (OCO-2): Spectrometers | |
| Sentinel-5 Precursor: TROPOspheric Monitoring Instrument (TROPOMI) | |
| Suomi National Polar-orbiting Partnership (Suomi NPP), NOAA-20/21: Ozone Mapping and Profiler Suite (OMPS) | |
| Terra: Measurements of Pollution In The Troposphere (MOPITT) | |
| Output Variables | Reanalysis of NO2, O3, CH4, CO2, CO, HCl, HNO3, N2O, H2O |
| Temporal Coverage | 2009 to 2018 (core period); will be extended to an earlier period of 2004 to 2008 and a later period 2019 to 2024 |
| Temporal Frequency | Hourly (selected two-dimensional fields), three-hourly (three-dimensional fields) |
| Spatial Coverage | Global |
| Spatial Resolution | 0.25 degree latitude x 0.25 degree longitude (nominally, 25 km x 25 km) |
| Vertical Resolution | 72 model layers, Earth surface to lower mesosphere (0.01 hPa, nominally 80 km) |
| Data Format | NetCDF4 (HDF5 compatible) |
Societal Impact
GEOS-CR provides a consistent, long-term look at past conditions, enabling better evaluation of air quality monitoring data. It allows for historical reanalysis of air pollution events and provides reference gridded datasets for training AI-based prediction systems, improving insight into impacts on human health and air quality.
Solution Resources
Need help using this Satellite Needs Working Group (SNWG) solution? For more information, see the GEOS-CR: SNWG Solution Fact Sheet.