Convection And Moisture EXperiment-2

The CAMEX-2 took place in September 1995 at Wallops Flight Facility to provide an intercomparison of water vapor measurement systems that would serve as a basis for validating GVaP (Global Energy and Water Cycle Experiment (GEWEX) Water Vapor Project) global data sets. MAMS was used to collected supporting visible and infrared measurements for the other instruments on the ER2 aircraft. Additionally, water vapor products from the GOES-8 satellite will be derived and made available to the experiment investigators.

CAMEX involved several ground-based instruments that were located near Wallops Island, Virginia. These instruments included a Raman lidar, Ground-Based HIS (GBHIS), CLASS, and conventional rawinsonde sites. The primary purpose for these instruments was to serve as ground truth for the aircraft instruments. Thus, the MAMS objectives reflect the availability of these data for "ground truthing."

The primary science objectives with MAMS for CAMEX were to:

1. intercompare HIS and MAMS data along the flight track for an extended region for variability assessment and integrated water content (IWC) retrieval comparison,
2. use HIS and MAMS data surrounding the Raman lidar to provide a three-way intercomparison/validation of water vapor signatures, and
3. use ground truth rawinsonde information for absolute verification and algorithm assessment/improvement. To achieve these objectives, the ER-2 made several flights over Wallops Island and the adjacent land and ocean.

The MAMS 6.5 micrometer channel has been used to map variations in upper tropospheric water vapor associated with a variety of atmospheric disturbances. The split-window channels at 11 and 12 micrometer allow surface temperature estimations and the determination of total-integrated water content (IWC) in a column of the atmosphere. In particular, the split-window channels can be used to monitor water vapor variability in the vicinity of Wallops Island. This is achieved by computing IWC over Wallops Island for several flights of MAMS and comparing the derived values to those from the HIS, the Raman lidar, rawinsondes, and the GBHIS. Furthermore, comparisons can be made with HIS during any portion of the flight. Previous investigations portray the utility of remotely sensed IWC and found reasonable agreement in their comparisons and were able to relate relatively high IWC values to the formation of clouds. Other studies for the retrieval of IWC suggest a poor performance at night due to a lower air/land temperature contrast. Since most of the CAMEX missions were flown at night, they provide an excellent opportunity to further investigate the nighttime results.

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Responsible Official: Dr. James L. Smoot (James.L.Smoot@nasa.gov)
Page Curator: Paul J. Meyer (paul.meyer@msfc.nasa.gov)

Last updated on: May 30, 1997