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Results from the NASA Water Vapor Project - NVAP

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SPECIAL INFORMATION ON THE NVAP CD_ROM

The NVAP CD-ROM is now available and includes monthly averaged total column and layered water vapor, browse images (gif format) and PC displayable animated movies. The time period is 1988 - 1994. The entire NVAP dataset (1998 - 1997) can be ordered from the Langley DAAC via the link at the bottom of this page, however, the DAAC does not have the data on CD-ROM. The DAAC is disseminating the NVAP data since the entire dataset, including daily global fields, would presently fill 9 CD-ROMs.

For a copy of the NVAP CD-ROM (free of charge) contact:

International GEWEX Project Office Suite 450, 1010 Wayne Avenue, Silver Spring, MD 20910 USA Tel: (301) 565-8345 Fax: (301) 565-8279 E-mail: gewex@cais.com

NVAP Project Overview

Prof. Thomas Vonder Haar, Dr. David Randel, and Prof. Graeme Stephens are co-investigators on the NASA Water Vapor Project (NVAP) at STC-METSAT. NVAP is a blended analysis of global water vapor. This product combines retrievals of precipitable water (or water vapor) from ground-based radiosondes, in microwave frequencies from the Special Sensor Microwave/Imager (SSM/I), and infrared TOVS observations from the NOAA operational series of satellites.

The NVAP data-set consists of global grids of 1x1 degree resolution with daily, pentad and monthly averages. The data-set spans 10 years from 1988 - 1997. Available parameters include: total and 3-layer blended PWC, liquid water path and cloud liquid water from SSM/I, separate grids of TOVS, SSM/I and Radiosonde PWC, and matching with the blended PWC are data source code (DSC) global grids. The DSC gives information on how each grid point was derived. This may include one of the input data-sets or a combination. Also the DSC grids are ordered by increasing confidence, with spatially filled data the lowest and gridpoints with radiosonde observations the highest.

Below are links to examples of the data-set and also results from studies with NVAP.


A New Global Water Vapor Dataset - NVAP reference paper (in HTML format).

Published in the June, 1996 AMS Bulletin. Includes color figures not included in original publication.

If you prefer Adobe Acrobat (.pdf) format of the original article: A New Global Water Vapor Dataset

NVAP Examples to show samples of available NVAP products.

NVAP Research Results shows our latest results using the NVAP data-set.


To order the NVAP data-set start up the WWW ordering system.


For more information about the NVAP data-sets, contact:

      Dr. David L. Randel (randel@cira.colostate.edu)
      CIRA
      Colorado State University
      Ft. Collins, CO  80523
      Tel: (970) 491-8219; Fax: (970) 491-8241


Last modified: October 2, 2001.

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