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Infrared Sounder Atmospheric Temperature and Humidity Profiles

This long-term satellite data record is made up of temperature and humidity observations at multiple pressure levels. The data set is produced primarily using input from infrared radiation (IR) sounder instruments such as High-Resolution Infrared Radiation Sounder (HIRS). Current data holdings span from 1978 through 2021 with data derived from HIRS instruments onboard the NOAA and Metop polar-orbiting satellite series. Future holdings are planned to also include data derived from other IR sensors (e.g., CrIS and IASI).

This dataset has been used as an input for other downstream products (e.g. NCEI's ISCCP CDR, NASA's Surface Radiation Budget) and can be used independently for long-term studies of global temperature and water vapor variability.

Metop Clear Sky 2 Meter Air Temperature map
A global map of clear-sky 2-meter air temperatures as observed by Metop-A on January 2, 2017 between 00:00:00-09:00:00 UTC. Illustrating that the 2-meter air temperature is just one of twelve available levels in the profile for any given location, a call out box of profile observations is indicated on the left for the location of (37.07° W, 44.93° S).

Access Methods

Bulk Download

HTTPS Web Accessible Folder

Subsets by Timeframe and Location

The THREDDS data server (link coming soon) can be used to download specific portions (subsets) of the data based on specific time-frames or geographic coordinates. Subsets are available in netCDF format.

Citation information

Cite as: Matthews, J. L., Y. Rao, L. Shi, NOAA National Centers for Environmental Information, and North Carolina State University Cooperative Institute for Satellite Earth System Studies. Infrared Sounder Temperature and Humidity Profiles dataset, Version 5.0.[indicate subset used]. NOAA National Centers for Environmental Information. https://doi.org/10.25921/zrs9-p639 Accessed [date]

Specifications

  • Geographic Location: Global
  • Spatial Resolution: Varies by input sensor
  • Temporal Resolution: Twice Daily

Atmospheric Pressure Levels

The temperature and specific humidity variables are available at the following hectopascal (hPa) atmospheric levels:

Temperature

  • Surface
  • 2 meters above surface
  • 1000 hPa
  • 850 hPa
  • 700 hPa
  • 600 hPa
  • 500 hPa
  • 400 hPa
  • 300 hPa
  • 200 hPa
  • 100 hPa
  • 50 hPa

Specific Humidity

  • 2 meters above surface
  • 1000 hPa
  • 850 hPa
  • 700 hPa
  • 600 hPa
  • 500 hPa
  • 400 hPa
  • 300 hPa

This data is most reliable under clear-sky conditions, and as such cloudy pixels have been removed and/or marked with quality flags.

Version history

The current version is v5.

Documentation

Recommended Uses and Limitations

The algorithm is developed based on clear-sky conditions. As such, the presence of clouds may degrade algorithm performance. Cloud flags are included to assist users in data selection. It is recommended that users filter for identified clear-sky pixels, with cloudiness probability flag (flag_cld) values of 0 or 4, before subsequent analyses.

Contact Information

Technical questions

irth_contacts@noaa.gov

Customer support

ncei.orders@noaa.gov

Related Products

The Infrared (IR) Sounder Atmospheric Temperature and Humidity Profiles are derived from IR sounder brightness temperature. Archival data tracking is planned for the near future.

The IR Sounder Upper Troposphere Humidity Brightness Temperature Climate Data Record provides monthly global clear-sky brightness temperatures from the High resolution Infrared Radiation Sounder (HIRS) and Infrared Atmospheric Sounding Interferometer (IASI) convolved channel 12. This gridded 2.5x2.5 degree resolution product provides data from 1978-present indicating signals of water vapor in the upper troposphere.

References

Paper containing validation of v4 algorithm:

Matthews, J.L.; Shi, L. Intercomparisons of Long-Term Atmospheric Temperature and Humidity Profile Retrievals. Remote Sensing. 2019, 11, 853. https://doi.org/10.3390/rs11070853

Paper describing v4 algorithm:

Shi, L.; Matthews, J.L.; Ho, S.-p.; Yang, Q.; Bates, J.J. Algorithm Development of Temperature and Humidity Profile Retrievals for Long-Term HIRS Observations Remote Sensing 2016, 8, 280. https://doi.org/10.3390/rs8040280