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Upper tropospheric water vapor: A field campaign of two Raman lidars, Airborne hygrometers, and RadiosondesWater vapor in the atmosphere plays an important role in radiative transfer and the process of radiative balance so critical for understanding global change. It is the principal ingredient in cloud formation, one of the most difficult atmospheric processes to model, and the most variable component of the Earth-atmosphere albedo. And as a free molecule, it is the most active infrared absorber and emitter, thus, the most important greenhouse gas. The radiative impact of water vapor is important at all levels of the atmosphere. Even though moisture decreases by several orders-of-magnitude from the Earth's surface to the tropopause, recent research has shown that, from a radiative standpoint, a small percentage change in water vapor at any level is nearly equivalent. Therefore accurate and precise measurements of this important atmospheric constituent are needed at all levels to evaluate the full radiative impact. The need for improved measurements in the upper troposphere is particularly important because of the generally hostile (very dry and cold) conditions encountered. Because of the importance of water vapor to the understanding of radiative transfer, the Department of Energy's Atmospheric Radiation Measurements (ARM) program initiated a series of measurement campaigns at the Cloud And Radiation Testbed (CART) site in Oklahoma, especially focused on atmospheric water vapor. Three water vapor intensive observation period (water vapor IOP) campaigns were planned. Two of the water vapor IOP campaigns have been completed: the first IOP was held during the fall of 1996 with a focus on boundary layer water vapor measurements, and the second was conducted during the fall of 1997 with a focus on both boundary layer moisture e and moisture in the upper troposphere. This paper presents a review of the intercomparisons of water vapor measurements in the upper troposphere aquired during the second water vapor IOP. Data to be presented include water vapor measurements ements from: two Raman Lidars, the NASA Goddard Scanning Raman Lidar (SRL) and the CART Raman Lidar (CARL), a number of Vaisala radiosondes launched during the IOP campaign, and a dew point hygrometer flown on the University of North Dakota Cessna Citation Aircraft.
Document ID
19980227664
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Melfi, S. Harvey
(Maryland Univ. Baltimore County Catonsville, MD United States)
Turner, Dave
(Pacific Northwest National Lab. Richland, WA United States)
Evans, Keith
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Whiteman, Dave
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Schwemmer, Geary
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Ferrare, Richard
(NASA Langley Research Center Hampton, VA United States)
Date Acquired
August 18, 2013
Publication Date
July 1, 1998
Publication Information
Publication: Nineteenth International Laser Radar Conference
Subject Category
Instrumentation And Photography
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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