Radiometric profiling of tropospheric temperature,

humidity and cloud liquidpresentation to the

Specialist Meeting on Microwave Remote Sensing 5-9 Nov 01, Boulder, Colorado, USA

by

Randolph Ware1,2, Fredrick Solheim1

1Radiometrics Corporation

2University Corporation for Atmospheric Research

Example radiometer, radiosonde and forecast temperature and humidity profiles

Radiometric profiler accuracy

Radiometer and radiosonde cloud liquid profile comparisons

Radiometric profiler reliability

Conclusions

Outline

Radiometric profiler

Temperature and humidity sounding in clear and cloudy conditions

Liquid water sounding in one cloud layer

12 microwave and 1 infrared channels

Solheim et al., Radio Science 33, 393-404, 1998

Lindenberg Germany

Radiometer temperature and humidity at Lindenberg 9-11 Feb 01. Arrows mark sonde launch times.

Radiosonde (solid) and radiometer (dashed) soundings at Lindenberg. Sonde and radiometer locations are ~200 m apart.

Radiometer (neural net and regression) accuracy compared to radiosondes [Gueldner and Spaenkuch, JAOT 18, 925-933, 2001].

More than 1 million hours in tropical to arctic conditions

MM5 forecast (left) and radiometer observations (right) at Boulder CO on 16 Feb 2001. Supercooled fog was

observed after 11:30 UT but was not forecast.

sonde

Maximum liquid = 0.15 g/m3

Maximum liquid = 0.30 g/m3

Denver radiosonde (50-km SE of Boulder) showing fogconsistent with radiometric observations but not forecast.

Fog

Radiometer display showing temperature inversion and supercooled liquid during upslope (16 Feb 2001, 18:22 UT).

Forecast (left) and radiometer (right) T and V at Lamont, OK, 21-22 Mar 00. Hourly MM5 forecasts are based on 0 Z analysis.

Forecast (left) and radiometer (right) RH and cloud liquid at Lamont 21-22 Mar 00. Sonde launch times are marked by arrows.

Sonde and radiometer measurements during cloud liquid conditions at Lamont 21 Mar 00, 17:31 UT.

Sonde and radiometer measurements during conditions of no cloud liquid at Lamont 21 Mar 00, 23:30 UT.

Sonde (in situ along trajectory) and radiometer (zenith 5o

beamwidth) liquid profiles at Mt. Washington (1999). Best and worst cases from 24 comparisons are shown.

Mobile profiler for improved boundary layer dispersion and transport, fog, supercooled liquid (aircraft icing hazard), ceiling, visibility, and

short term precipitation forecasting (K. Knupp, U. Alabama).

Conclusions Radiometric profiling provides continuous

temperature, humidity and cloud liquid profiles

Profiler accuracy demonstrated by statistical comparison with radiosondes

Reliability demonstrated in variety of locations

Observations of fog and cloud liquid profiles

Tropospheric profiling can improve local high resolution modeling and forecasting

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