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  • Author or Editor: W. L. Ecklund x
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R. R. Rogers
,
W. L. Ecklund
,
D. A. Carter
,
K. S. Gage
, and
S. A. Ethier

A small UHF radar wind profiler was operated over a 40-day period during the summer of 1990 at a site on the windward coast of the island of Hawaii. It provided continuous measurements of winds up to the height of the trade-wind inversion, which varied in altitude from about 2 to 4 km during the course of the experiments. The inversion was readily discernible in the data as an elevated layer of high reflectivity, caused by the sharp gradient of refractive index at that level. With a wavelength of 33 cm, the profiler has about the same sensitivity to light rain as to moderately reflective clear air. The data have provided unexpected information on rain development, wave motions on the inversion, sustained vertical air motions at low levels, and interactions between convection and the inversion echo. This paper gives examples of some of the observations, indicating the wide range of applications of boundary-layer profilers.

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B. E. Martner
,
D. B. Wuertz
,
B. B. Stankov
,
R. G. Strauch
,
E. R. Westwater
,
K. S. Gage
,
W. L. Ecklund
,
C. L. Martin
, and
W. F. Dabberdt

Several ground-based remote sensors were operated together in Colorado during February and March 1991 to obtain continuous profiles of the kinematic and thermodynamic structure of the atmosphere. Instrument performance is compared for five different wind profilers. Each was equipped with Radio Acoustic Sounding System (RASS) capability to measure virtual temperature. This was the first side-by-side comparison of all three of the most common wind-profiler frequencies: 50, 404, and 915 MHz. The 404-MHz system was a NOAA Wind Profiler Demonstration Network (WPDN) unit. Dual-frequency microwave radiometers that measured path-integrated water vapor and liquid water content were also evaluated. Frequent rawinsonde launches from the remote-sensor sites provided an extensive set of in situ measurements for comparison. The winter operations provide a severe test of the profiler/RASS capabilities because atmospheric scattering is relatively weak and acoustic attenuation is relatively strong in cold, dry conditions. Nevertheless, the lower-frequency systems exhibited impressive height coverage for wind and virtual temperature profiling, whereas the high-frequency units provided higher-resolution measurements near the surface. Comparisons between remote sensor and rawinsonde data generally showed excellent agreement. The results support more widespread use of these emerging technologies.

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