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Merged PBL Temperature, Water Vapor, and Height Products

Using GNSS-RO and sounder data, this SNWG solution provides global atmospheric profiles of temperature and water vapor in the Planetary Boundary Layer (PBL), as well as PBL height.

Background

The Planetary Boundary Layer (PBL) is the interface between Earth’s surface and lowermost 2 to 3 km of the atmosphere. Knowing its highly dynamic properties is vital to understanding the diurnal, seasonal, and climate-scale variations of Earth’s atmospheric processes and key to cloud formation and pollution dispersal. 

Both infrared and microwave sounders and Global Navigation Satellite Systems-Radio Occultation (GNSS-RO) measure atmospheric temperature and moisture. Combining hyperspectral infrared and microwave sounder data with GNSS-RO data into a merged global product will advance PBL process science and will improve weather forecasting applications. The Satellite Needs Working Group (SNWG) PBL solution will provide a needed dataset with current capabilities for requesting agencies as new technical capabilities mature.

Status: Version 1 Coming Soon

This solution is currently in development, with an initial data release expected in mid-2026. The initial version will perform a data fusion on the RO and infrared and microwave sounding retrievals. 

To develop the second version (expected in mid-2028), joint retrievals and machine learning algorithms will be developed to combine the different measurements more optimally, aiming to generate a more accurate product with higher spatial resolution. 

Solution Characteristics

ProductsThreshold (Version 1)Threshold (Version 1)Baseline (Version 2)Baseline (Version 2)
Input Sources
  • Atmospheric Infrared Sounder (AIRS)
  • Cross-track Infrared Sounder (CrIS)
  • Advanced Microwave Sounding Unit (AMSU)
  • Advanced Technology Microwave Sounder (ATMS)
  • Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC)
  • COSMIC-2
  • Sentinel-6
  • Gravity Recovery and Climate Experiment Follow-On (GRACE-FO)
  • Spire 
  • Additional RO datasets will likely be included subject to availability
Output Variables
  • Temperature profiles and water vapor profiles at vertical height grids of 100 m within the PBL and above (0 to approximately 3 altitudes)
  • PBL height
Processing Level2323
Temporal Coverage2014-20232014-20232006 - Present2006 - Present
Temporal SamplingDependent on GNSS-RO sounding sampling (varies over the time period but up to 10,000 profiles per day globally)MonthlyDependent on GNSS-RO sounding sampling (varies over the time period but up to 10,000 profiles per day globally)Monthly
LatencyPotentially real-time processing (exact latency to be determined)Potentially ~1 month (exact latency to be determined)Potentially real-time processing (exact latency to be determined)Potentially ~1 month (exact latency to be determined)
Spatial CoverageGlobalGlobalGlobalGlobal
Spatial Resolution

Horizontal: 50 km

Vertical: 200 m

Horizontal: approximately 2 degrees

Vertical: approximately 200 m

Horizontal: 15 km

Vertical: 200 m

Horizontal: approximately 1 degree

Vertical: approximately 200 m

Societal Impact

The Merged PBL Temperature, Water Vapor, and Height products will provide accurate PBL height and 3D profiles of temperature and water vapor in the 2 to 3 km of the atmosphere closest to Earth's surface. Such data are essential for weather and air quality forecasting and for a variety of applications in aviation, communications, and defense operations. This work also contributes to an enhanced understanding of PBL as identified in the 2017 Decadal Survey.

Solution Resources

Need help using this solution? For more information, access the following resources: