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Description

This level 2 support product is generated by the SiFSAP (Single Field-of-View Sounder Atmospheric Products) algorithm. The SIFSAP algorithm provides retrieval for each sounder Field of View (FOV), therefore, it has 3-times higher horizontal spatial resolution and 9-time denser products compared to other current IR sounder products. Since SiFSAP is an FOV-based algorithm, its product variables have an additional dimension which represents the number of FOVs. For CrIS instrument, there are 9 FOVs for each Field of Regard (FOR). The SiFSAP Level-2 retrieval products contain a variety of geophysical parameters retrieved from IR/MW sounder suites measurements, including profiles of temperature, water vapor and trace gas species as well as clouds and surface properties. This support product provides height vertical sampling (up to 98 levels) and also includes more detailed Empirical Orthogonal Function (EOF) information like averaging kernels. A level 2 granule has been set as 6 minutes of data. There are 240 granules per day, with an orbit repeat cycle of approximately 16 day.

Product Summary

Platforms
Suomi-NPP
Instruments
ATMS ,
CrIS
Spatial Extent

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

Location
GLOBAL
Coordinate System
GEODETIC
Granule Spatial Representation
GEODETIC
Temporal Extent
2015-11-02
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
C2782339991-GES_DISC
Data State
ACTIVE
Number of Files/Granules
460114
Processing Level
2
Published
Updated
Science Keywords
Surface Pressure ,
Surface Temperature ,
Air Temperature ,
Upper Air Temperature ,
Layered Precipitable Water ,
Total Precipitable Water ,
Water Vapor Profiles ,
Skin Temperature ,
Sea Surface Temperature ,
Liquid Water Equivalent ,
Relative Humidity ,
Specific Humidity ,
Atmospheric Ozone ,
Total Ozone ,
Atmospheric Carbon Monoxide ,
Methane ,
Cloud Optical Depth/Thickness ,
Temperature Gradient Rate

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

Liu, X. (2022). Sounder SIPS: Suomi NPP CrIMSS Level 2 SiFSAP Support: Atmosphere cloud and surface geophysical state per footprint V2 [Data set]. NASA Goddard Earth Sciences Data and Information Services Center. https://doi.org/10.5067/XQMJMVTQSGIS Date Accessed: 2026-05-16

Documents

READ-ME

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

SCIENCE DATA PRODUCT VALIDATION

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
mw/mw_surf_temp_dof The trace of the averaging kernel matrix as a measure of the amount of information about the surface temperature extracted from the measured microwave radiation in the MW-only retrieval step. 1 float32 9.9692099683869E+36 N/A N/A N/A
mw/mw_surf_temp_err mw_surf_temp error estimate kelvin float32 9.9692099683869E+36 N/A N/A N/A
mw/mw_surf_temp_qc mw_surf_temp QC flag N/A int8 -127 N/A N/A N/A
mw/mw_tpause_gp_hgt Derived tropopause geopotential height from the MW-only retrieval step, where tropopause is determined according to the WMO definition m float32 9.9692099683869E+36 N/A N/A N/A
mw/mw_tpause_gp_hgt_qc mw_tpause_gp_hgt QC flag N/A int8 -127 N/A N/A N/A
mw/mw_tpause_pres Derived tropopause pressure from the MW-only retrieval step, where tropopause is determined according to the WMO definition Pa float32 9.9692099683869E+36 N/A N/A N/A
mw/mw_tpause_pres_qc mw_tpause_pres QC flag N/A int8 -127 N/A N/A N/A
mw/mw_tpause_temp Derived tropopause temperature from the MW-only retrieval step, where tropopause is determined according to the WMO definition kelvin float32 9.9692099683869E+36 N/A N/A N/A
mw/mw_tpause_temp_qc mw_tpause_temp QC flag N/A int8 -127 N/A N/A N/A
n2o_dof The trace of the averaging kernel matrix as a measure of the amount of information about the nitrous oxide profile extracted from the measured radiation. 1 float32 9.9692099683869E+36 N/A N/A N/A
n2o_mmr_midtrop Nitrous Oxide mass mixing ratio to dry air at 40000 Pa, near the peak of sensitivity kg / kg float32 9.9692099683869E+36 N/A N/A N/A
n2o_mmr_midtrop_err n2o_mmr_midtrop error estimate kg / kg float32 9.9692099683869E+36 N/A N/A N/A
n2o_mmr_midtrop_qc n2o_mmr_midtrop QC flag N/A int8 -127 N/A N/A N/A
o3_dof The trace of the averaging kernel matrix as a measure of the amount of information about the ozone profile extracted from the measured radiation. 1 float32 9.9692099683869E+36 N/A N/A N/A
o3_mmr ozone mass mixing ratio to dry air kg / kg float32 9.9692099683869E+36 N/A N/A N/A
o3_mmr_err o3_mmr error estimate kg / kg float32 9.9692099683869E+36 N/A N/A N/A
o3_mmr_qc o3_mmr QC flag N/A int8 -127 N/A N/A N/A
o3_tot Total column ozone. (Multiply by 4.670e4 to convert to Dobson Units from kg m^-2) kg m-2 float32 9.9692099683869E+36 N/A N/A N/A
o3_tot_err o3_tot error estimate kg m-2 float32 9.9692099683869E+36 N/A N/A N/A
o3_tot_qc o3_tot QC flag N/A int8 -127 N/A N/A N/A
obs_id unique observation identifier: yyyymmddThhmm.aaSxx. Includes gran_id plus 2-digit along-track index (01-45), scene identifier (E=earth, H=hot, C=cold) and 2-digit cross-track index (01-30). N/A OTHER N/A N/A N/A N/A
obs_time_tai93 TAI93 earth view observation midtime for each FOV in seconds since 1993-01-01 00:00z seconds since 1993-01-01 00:00 float64 9.9692099683869E+36 N/A N/A N/A
obs_time_utc UTC earth view observation midtime for each FOV as an array of integers: year, month, day, hour, minute, second, millisec, microsec N/A uint16 65535 N/A N/A N/A
rel_hum relative humidity over equilibrium phase 1 float32 9.9692099683869E+36 N/A N/A N/A
rel_hum_err rel_hum error estimate 1 float32 9.9692099683869E+36 N/A N/A N/A
rel_hum_qc rel_hum QC flag N/A int8 -127 N/A N/A N/A
sat_alt satellite altitude with respect to earth model at scan_mid_time m float32 9.9692099683869E+36 N/A N/A N/A
sat_att satellite attitude at scan_mid_time. An orthogonal triad. First element is angle about the +x (roll) ORB axis. +x axis is positively oriented in the direction of orbital flight. Second element is angle about +y (pitch) ORB axis. +y axis is oriented normal to the orbit plane with the positive sense opposite to that of the orbit's angular momentum vector H. Third element is angle about +z (yaw) axis. +z axis is positively oriented Earthward parallel to the satellite radius vector R from the spacecraft center of mass to the center of the Earth. degree float32 9.9692099683869E+36 N/A N/A N/A
sat_azi satellite azimuth angle at the center of the FOV (clockwise from North) degree float32 9.9692099683869E+36 N/A N/A N/A
sat_pos satellite ECR position at scan_mid_time m float32 9.9692099683869E+36 N/A N/A N/A
sat_range line of sight distance between satellite and FOV center m float32 9.9692099683869E+36 N/A N/A N/A
sat_sol_azi solar azimuth angle at the satellite (clockwise from North) degree float32 9.9692099683869E+36 N/A N/A N/A
sat_sol_zen solar zenith angle at the satellite degree float32 9.9692099683869E+36 N/A N/A N/A
sat_vel satellite ECR velocity at scan_mid_time m s-1 float32 9.9692099683869E+36 N/A N/A N/A
sat_zen satellite zenith angle at the center of the FOV degree float32 9.9692099683869E+36 N/A N/A N/A
scan_mid_time TAI93 at middle of earth scene scans seconds since 1993-01-01 00:00 float64 9.9692099683869E+36 N/A N/A N/A
solar_beta_angle Beta angle for the spacecraft orbit, determining the percentage of the orbit that the spacecraft is in direct sunlight. degree float32 9.9692099683869E+36 N/A N/A N/A
sol_azi solar azimuth angle at the center of the FOV (clockwise from North) degree float32 9.9692099683869E+36 N/A N/A N/A
sol_zen solar zenith angle at the center of the FOV degree float32 9.9692099683869E+36 N/A N/A N/A
spatial_lbl list of spatial directions (X, Y, Z) N/A OTHER N/A N/A N/A N/A
spec_hum mass fraction of water vapor in moist air kg / kg float32 9.9692099683869E+36 N/A N/A N/A
spec_hum_err spec_hum error estimate kg / kg float32 9.9692099683869E+36 N/A N/A N/A
spec_hum_qc spec_hum QC flag N/A int8 -127 N/A N/A N/A
subsat_lat sub-satellite latitude at scan_mid_time degrees_north float32 9.9692099683869E+36 N/A N/A N/A
subsat_lon sub-satellite longitude at scan_mid_time degrees_east float32 9.9692099683869E+36 N/A N/A N/A
sun_glint_dist Distance from the center of the calculated sun glint spot to the center of the spot. Note that there may not be a glint for cloudy or land cases and in ocean cases the glint can move based on wind conditions. Fill for night observations. m float32 9.9692099683869E+36 N/A N/A N/A
sun_glint_lat sun glint spot latitude at scan_mid_time. Fill for night observations. degrees_north float32 9.9692099683869E+36 N/A N/A N/A
sun_glint_lon sun glint spot longitude at scan_mid_time. Fill for night observations. degrees_east float32 9.9692099683869E+36 N/A N/A N/A
surf_air_temp Air temperature at Earth surface pressure derived from air_temp and prior_surf_pres kelvin float32 9.9692099683869E+36 N/A N/A N/A
surf_air_temp_err surf_air_temp error estimate kelvin float32 9.9692099683869E+36 N/A N/A N/A
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