Water Vapor Network at SGP Site Goes Offline

 
Published: 15 August 2010
Each of the 24 solar-powered GPS stations streamed data via a wireless network to the SGP Central Facility for data collection and storage.

After nearly eleven years, the Single Frequency GPS Water Vapor Network field campaign at the ARM Southern Great Plains (SGP) site came to a close on July 1, 2010. Installed between 1999 and 2000, this network consisted of 24 GPS stations operating within an 8-kilometer radius around the SGP Central Facility near Lamont, Oklahoma. Developed to function as a single instrument, the network simultaneously measured “slant water vapor” in the path of 5 to 10 GPS satellites above the ground stations. The dense spacing of these stations provided continuous, all-weather observations of atmospheric water vapor over horizontal scales as small as one kilometer. These data are useful for studying water vapor structure, variability, temporal cycles, and evolution during cloud formation and convective events.

The network used low-cost single-frequency GPS receivers to densely sample a relatively small atmospheric column. Nested within a larger spatial scale dual-frequency network, the collective data provide more detail than either network by itself.

Derived products from this network are estimates of (1) column-integrated precipitable water vapor at 30-minute intervals and (2) line-of-sight slant water vapor in the direction of each visible GPS satellite at 30-second intervals. Some data collected from this campaign are available in the ARM Data Archive; final data will be added in the future.