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Description

WARNING: To users of the derived product “co_mmr_midtrop” (carbon monoxide mass mixing ratio to dry air [kg/kg] at ~500 hPa). This variable has a significant bias due to a conversion error: the molecular weight of carbon dioxide (CO2, 44.01 g/mol) was used instead of carbon monoxide (CO, 28.01 g/mol). To correct, simply multiply “co_mmr_midtrop” by 28.01/44.01. Alternatively, derive a profile of mass mixing ratio from scratch using the retrieved column density values (“mol_lay/co_mol_lay”) in the Level 2 files. For further questions or concerns please contact the Sounder SIPS at: sounder.sips@jpl.nasa.gov

The CLIMCAPS (Community Long-term Infrared Microwave Coupled Product System) algorithm is used to analyze data from the Cross-track Infrared Sounder/Advanced Technology Microwave Sounder (CrIS/ATMS) instruments, also known as CrIMSS (Cross-track Infrared and Microwave Sounding Suite). The CrIS/ATMS instruments used for this product are on board the Suomi National Polar-orbiting Partnership (SNPP) platform and use the Full Spectral Resolution (FSR) data. The CrIS instrument is a Fourier transform spectrometer with a total of 2211 FSR infrared sounding channels covering the longwave (645-1095 cm-1), midwave (1210-1750 cm-1), and shortwave (2000-2550 cm-1) spectral regions. The ATMS instrument is a cross-track scanner with 22 channels in spectral bands from 23 GHz through 183 GHz.

The CLIMCAPS algorithm uses an Optimal Estimation methodology and uses an a-priori first guess to start the process. A CLIMCAPS sounding is comprised of a set of parameters that characterizes the full atmospheric state and includes a variety of geophysical parameters derived from the CrIMSS data. These include surface temperature and infrared emissivity; full atmosphere profiles of temperature, water vapor and ozone; infrared effective cloud top characteristics; carbon monoxide, methane, carbon dioxide, sulfur dioxide, nitrous oxide, and nitric acid.

A level 2 granule has been set as 6 minutes of data, 30 footprints cross track by 45 lines along track. There are 240 granules per day, with an orbit repeat cycle of approximately 16 day.

The CLIMCAPS algorithm uses data from the second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) as a first-guess for the atmospheric state. Because MERRA-2 products typically have a latency from 3 to 7 weeks, so too do the CLIMCAPS products.

Product Summary

Platforms
Suomi-NPP
Instruments
CrIS ,
ATMS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Location
GLOBAL
Coordinate System
GEODETIC
Granule Spatial Representation
GEODETIC
Temporal Extent
2015-11-02 to Present
Data Partner
Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/GESDI
Concept ID
C1692982075-GES_DISC
Data State
ACTIVE
Number of Files/Granules
459480
Processing Level
2
Published
Updated
Science Keywords
Tropospheric Ozone ,
Tropopause ,
Atmospheric Chemistry ,
Carbon And Hydrocarbon Compounds ,
Methane ,
Outgoing Longwave Radiation ,
Atmospheric Temperature ,
Surface Temperature ,
Air Temperature ,
Skin Temperature ,
Upper Air Temperature ,
Vertical Profiles ,
Atmospheric Water Vapor ,
Layered Precipitable Water ,
Total Precipitable Water ,
Cloud Properties ,
Cloud Fraction ,
Cloud Top Temperature ,
Precipitation ,
Skin Temperature ,
Ocean Temperature ,
Sea Surface Skin Temperature

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Sounder SIPS, & Barnet, C. (2020). Sounder SIPS: Suomi NPP CrIMSS Level 2 CLIMCAPS Full Spectral Resolution: Atmosphere cloud and surface geophysical state V2 [Data set]. NASA Goddard Earth Sciences Data and Information Services Center. https://doi.org/10.5067/62SPJFQW5Q9B Date Accessed: 2026-05-14

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
fov_obs_id unique earth view observation identifier for FOV: yyyymmddThhmm.aaExx.f . Includes gran_id plus 2-digit along-track index (01-45), 2-digit cross-track index (01-30), and 1-digit FOV number (1-9). N/A OTHER N/A N/A N/A N/A
fov_surf_alt mean surface altitude wrt earth model over the FOV m float32 9.9692099683869E+36 N/A N/A N/A
fov_surf_alt_sdev standard deviation of surface altitude within the FOV m float32 9.9692099683869E+36 N/A N/A N/A
gp_hgt Geopotential is the sum of the specific gravitational potential energy relative to the geoid and the specific centripetal potential energy. Geopotential height is the geopotential divided by the standard acceleration due to gravity. m float32 9.9692099683869E+36 N/A N/A N/A
gp_hgt_err gp_hgt error estimate m float32 9.9692099683869E+36 N/A N/A N/A
gp_hgt_qc gp_hgt QC flag N/A int8 -127 N/A N/A N/A
h2o_liq_mol_lay cloud liquid water layer total 1 float32 9.9692099683869E+36 N/A N/A N/A
h2o_liq_mol_lay_err h2o_liq_mol_lay error estimate 1 float32 9.9692099683869E+36 N/A N/A N/A
h2o_liq_mol_lay_qc h2o_liq_mol_lay QC flag N/A int8 -127 N/A N/A N/A
h2o_liq_tot total column cloud liquid water kg m-2 float32 9.9692099683869E+36 N/A N/A N/A
h2o_liq_tot_err h2o_liq_ tot error estimate kg m-2 float32 9.9692099683869E+36 N/A N/A N/A
h2o_liq_tot_qc h2o_liq_ tot QC flag N/A int8 -127 N/A N/A N/A
h2o_vap_dof The trace of the averaging kernel matrix as a measure of the number of pieces of information about the water vapor profile provided by the physical retrieval step. 1 float32 9.9692099683869E+36 N/A N/A N/A
h2o_vap_tot total precipitable water vapor kg / m2 float32 9.9692099683869E+36 N/A N/A N/A
h2o_vap_tot_err h2o_vap_tot error estimate kg / m2 float32 9.9692099683869E+36 N/A N/A N/A
h2o_vap_tot_qc h2o_vap_tot QC flag N/A int8 -127 N/A N/A N/A
hno3_dof The trace of the averaging kernel matrix as a measure of the number of pieces of information about the nitric acid profile provided by the physical retrieval step. 1 float32 9.9692099683869E+36 N/A N/A N/A
ir_precip_est_24hr The thickness of a layer of liquid water equivalent to the estimated preciptitation over 24 hours. m float32 9.9692099683869E+36 N/A N/A N/A
ir_precip_est_24hr_err ir_precip_est_24hr error estimate m float32 9.9692099683869E+36 N/A N/A N/A
ir_precip_est_24hr_qc ir_precip_est_24hr QC flag N/A int8 -127 N/A N/A N/A
land_frac land fraction over the FOR 1 float32 9.9692099683869E+36 N/A N/A N/A
lat latitude of FOR center degrees_north float32 9.9692099683869E+36 N/A N/A N/A
lat_bnds latitudes of points forming a polygon around the perimeter of the FOV degrees_north float32 9.9692099683869E+36 N/A N/A N/A
lat_geoid latitude of FOR center on the geoid (without terrain correction) degrees_north float32 9.9692099683869E+36 N/A N/A N/A
local_solar_time local apparent solar time in hours from midnight hours float32 9.9692099683869E+36 N/A N/A N/A
lon longitude of FOR center degrees_east float32 9.9692099683869E+36 N/A N/A N/A
lon_bnds longitudes of points forming a polygon around the perimeter of the FOV degrees_east float32 9.9692099683869E+36 N/A N/A N/A
lon_geoid longitude of FOR center on the geoid (without terrain correction) degrees_east float32 9.9692099683869E+36 N/A N/A N/A
mean_anom_wrt_equat spacecraft mean anomaly measured with respect to the ascending node degree float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/ch4_mol_lay Methane layer total on 100 layers molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/ch4_mol_lay_err ch4_mol_lay error estimate molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/ch4_mol_lay_qc ch4_mol_lay QC flag N/A int8 -127 N/A N/A N/A
mol_lay/co_mol_lay Carbon monoxide layer total on 100 layers molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/co_mol_lay_err co_mol_lay error estimate molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/co_mol_lay_qc co_mol_lay QC flag N/A int8 -127 N/A N/A N/A
mol_lay/h2o_vap_mol_lay Water vapor layer total on 100 layers molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/h2o_vap_mol_lay_err h2o_vap_mol_lay error estimate molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/h2o_vap_mol_lay_qc h2o_vap_mol_lay QC flag N/A int8 -127 N/A N/A N/A
mol_lay/hno3_mol_lay nitric acid layer total on 100 layers molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/hno3_mol_lay_err hno3_mol_lay error estimate molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/hno3_mol_lay_qc hno3_mol_lay QC flag N/A int8 -127 N/A N/A N/A
mol_lay/n2o_mol_lay nitrous oxide layer total on 100 layers molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/n2o_mol_lay_err n2o_mol_lay error estimate molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/n2o_mol_lay_qc n2o_mol_lay QC flag N/A int8 -127 N/A N/A N/A
mol_lay/o3_mol_lay Ozone layer total on 100 layers molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/o3_mol_lay_err o3_mol_lay error estimate molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/o3_mol_lay_qc o3_mol_lay QC flag N/A int8 -127 N/A N/A N/A
mol_lay/so2_mol_lay sulfur dioxide layer total on 100 layers molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/so2_mol_lay_err so2_mol_lay error estimate molecules / m2 float32 9.9692099683869E+36 N/A N/A N/A
mol_lay/so2_mol_lay_qc so2_mol_lay QC flag N/A int8 -127 N/A N/A N/A
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