U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Global Positioning System (GPS) Revolutionizes Water Vapor Measurements
Published: July 30, 2003
Posted: August 13, 2003

Results from an Atmospheric Radiation Measurement (ARM) study confirm the accuracy of using GPS for water vapor measurements. Simultaneous measurements from these multiple receivers are being used to construct high resolution, 3D maps of atmospheric water vapor. These 3D maps will be an important data source in the development of numerical weather prediction models. The experiment compared water vapor path measurements from GPS with simultaneous measurements obtained from a ground-based microwave radiometer (MWR) at the ARM central facility in Oklahoma. The MWR is self-calibrated based on fundamental physics and its measurements are an absolute standard. A comparison of over 100,000 measurements made over a span of two months showed a correlation between water vapor measurements made with the two technologies of 0.99 and a root-mean-square error of 1.3 mm or about 2-3%. These results clearly demonstrate the ability of networks of GPS receivers to accurately measure instantaneous water vapor along the transmission path. Thus the GPS units, at a one tenth the cost of the MWR, will provide an accurate, cost-effective technology for measuring the most abundant greenhouse gas, water vapor. Since water vapor absorbs energy in the atmosphere, having accurate measurements of its atmospheric concentration are critical for climate studies. The GPS receiver used in this experiment is one of 33 such receivers distributed around the ARM site in Oklahoma and one of hundreds in the continental U.S.

Contact: Wanda R. Ferrell, SC-74, 301-903-0043
Topic Areas:

  • Research Area: Atmospheric System Research
  • Facility: DOE ARM User Facility

Division: SC-23.1 Climate and Environmental Sciences Division, BER
      (formerly SC-74 Environmental Sciences Division, OBER)

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)