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Thousands of comparisons between total precipitable water vapor (PWV) obtained from radiosonde (Vaisala RS80-H) profiles and PWV retrieved from a collocated microwave radiometer (MWR) were made at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains Cloud and Radiation Testbed (SGP CART) site in northern Oklahoma from 1994 to 2000.(More)
—Ground-based two-channel microwave radiometers (MWRs) have been used for over 15 years by the Atmospheric Radiation Measurement (ARM) program to provide observations of downwelling emitted radiance from which precipitable water vapor (PWV) and liquid water path (LWP)—two geophysical parameters critical for many areas of atmospheric research—are retrieved.(More)
[1] A microwave radiometer is described that provides continuous thermodynamic (temperature, water vapor, and moisture) soundings during clear and cloudy conditions. The radiometric profiler observes radiation intensity at 12 microwave frequencies, along with zenith infrared and surface meteorological measurements. Historical radiosonde and neural network(More)
1. INTRODUCTION The Atmospheric Radiation Measurement (ARM) Program is focused on improving the treatment of radiation transfer in models of the atmospheric general circulation, as well as on improving parameterizations of cloud properties and formation processes in these models (USDOE, 1990). To help achieve these objectives, ARM is deploying several(More)
The two-channels microwave water vapor radiometer (MWR) shown in Fig. 1 measures brightness temperatures at the microwave frequencies of 23.8 and 31.4 GHz. Brightness temperatures are converted to opacity and used to retrieve PWV and LWP by means of a linear statistical regression. Root mean square error of retrieval is 0.4 mm for PWV and 0.02 mm (20 g/m 2)(More)
The sensing of precipitable water (PW) using the Global Positioning System (GPS) in the near Tropics is investigated. GPS data acquired from the Central Weather Bureau's Taipei weather station in Banchao (Taipei), Taiwan, and each of nine International GPS Service (IGS) stations were utilized to determine independently the PW at the Taipei site from 18 to(More)
In the fall of 1997 the Atmospheric Radiation Measurement program conducted a study of water-vapor-abundance-measurement at its southern Great Plains site. The large number of instruments included four solar radiometers to measure the columnar water vapor (CWV) by measuring solar transmittance in the 0.94-mum water-vapor absorption band. At first, no(More)
ater vapor is the dominant greenhouse gas in the atmosphere. It also plays an important role in the life cycle of clouds and precipitation , the transfer of latent and sensible heat, and in atmospheric chemistry. Unlike long-lived trace gases Results from a series of experiments focused on the lower troposphere have pointed the way to significantly(More)