Solar radiation enters the Earth's atmosphere with a portion being scattered by clouds and aerosols.

Processing, archiving and distributing Earth science data
at the NASA Langley Research Center

NVAP

NVAP Data and Information

The NASA Water Vapor Project (NVAP) total column (integrated) water vapor data sets comprise a combination of radiosonde observations, Television and Infrared Operational Satellite (TIROS) Operational Vertical Sounders (TOVS), and Special Sensor Microwave/Imager (SSM/I) data sets. These data sets span 14 years (1988 - 2001) and contain total and layered global water vapor data. The spatial coverage is global for all data sets.

 

The NASA MEaSUREs program began in 2008 and has the goal of creating stable, community accepted Earth System Data Records (ESDRs) for a variety of geophysical time series. A reanalysis and extension of the NASA Water Vapor Project (NVAP), called NVAP-M is being performed as part of this program. When processing is complete, NVAP-M will span 1987-2010. Read about changes in the new version.

 

NOTICE: The NASA Water Vapor Project (NVAP) data sets listed on this page are previous releases.  The most recent NVAP Data Sets are ordered from the NVAP-M Data and Information.

NVAP-Next Generation (NVAP-NG) phase extends into years 2000 and 2001 and offers increased spatial and temporal resolution.

Products Temporal Resolution Spatial Resolution Temporal Coverage
NVAP NG CLW

12 hour, daily, monthly, and annual averages

0.5° x 0.5° global grid

01/01/2000 - 12/31/2001

NVAP NG LWP

12 hour, daily, monthly, and annual averages

0.5° x 0.5° global grid

01/01/2000 - 12/31/2001

NVAP NG PWC

12 hour, daily, monthly, and annual averages

0.5° x 0.5° global grid

01/01/2000 - 12/31/2001

NVAP multi-year total and layered global water vapor data covering 1988 - 1999.

Products Temporal Resolution Spatial Resolution Temporal Coverage
NVAP PW MERGD MNTHLY

Monthly and yearly averages

1° x 1° global grid

01/01/1988 - 12/31/1999

NVAP PW MERGD PDAILY

Daily and pentad averages

1° x 1° global grid

01/01/1988 - 12/31/1999

NVAP SONDE PW DAILY

Daily averages

1° x 1° global grid

01/01/1988 - 12/31/1999

NVAP SSMI CLW Daily

Daily averages

1° x 1° global grid

01/01/1993 - 12/31/1999

NVAP SSMI LWP Daily

Daily averages

1° x 1° global grid

01/01/1988 - 12/31/1999

NVAP SSMI MNTHLY

Monthly averages

1° x 1° global grid

01/01/1988 - 12/31/1999

NVAP SSMI PW DAILY

Daily averages

1° x 1° global grid

01/01/1988 - 12/31/1999

NVAP TOVS PW Daily

Daily averages

1° x 1° global grid

01/01/1988 - 12/31/1999

NVAP-M Data and Information

NVAP read software is product dependent. If read software is available, a "read software" tab will appear on the product landing page.