Article Type:
Research Article

A Calorimetric Jet Engine Technique for Estimating the Condensed Water Mixing Ratio in Cumulus Clouds for Cloud Physical and Weather Modification Research

Griffith Morgan Thunderstorm and Hail Prevention Research Center, Ente Regionale per la Promozione e lo Sviluppo dell’Agricoltura, Centro di Servizi Agricoli, Villa Chiozza, Cervignano, Italy

Search for other papers by Griffith Morgan in
Current site
Google Scholar
PubMed Close
,
Mark Schormann CloudQuest, Nelspruit, Pumalanga, South Africa

Search for other papers by Mark Schormann in
Current site
Google Scholar
PubMed Close
,
Erika Botha CloudQuest, Nelspruit, Pumalanga, South Africa

Search for other papers by Erika Botha in
Current site
Google Scholar
PubMed Close
, and
Graeme K. Mather CloudQuest, Nelspruit, Pumalanga, South Africa

Search for other papers by Graeme K. Mather in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Nov 2000
DOI:
https://doi.org/10.1175/1520-0450(2000)039<1837:ACJETF>2.0.CO;2
Page(s):
1837–1844
Restricted access

Abstract

A technique has been developed for deriving estimates of condensed water mixing ratio in cumulus clouds from measurements of potential temperature in the air in the compressor of a jet engine. Condensate that enters the engine at low temperatures (near −10°C) is evaporated in the compressor, causing a cooling of the air that is proportional to the amount of condensate evaporated. An important element of the technique is a correction for the time response of the temperature measurement system mounted in the compressed air. This new technique is simpler and more robust than an earlier technique based on measurement of the vapor concentration in the compressed air by an optical extinction (at Lyman-alpha wavelength) method. The values of condensed water mixing ratio derived from the new system are shown to be similar to those from the optical extinction system, previously reported in the literature.

* Deceased.

Corresponding author address: Griffith Morgan, 204 28th St., Boulder, CO 80303.

gmmorgan@ix.netcom.com

Abstract

A technique has been developed for deriving estimates of condensed water mixing ratio in cumulus clouds from measurements of potential temperature in the air in the compressor of a jet engine. Condensate that enters the engine at low temperatures (near −10°C) is evaporated in the compressor, causing a cooling of the air that is proportional to the amount of condensate evaporated. An important element of the technique is a correction for the time response of the temperature measurement system mounted in the compressed air. This new technique is simpler and more robust than an earlier technique based on measurement of the vapor concentration in the compressed air by an optical extinction (at Lyman-alpha wavelength) method. The values of condensed water mixing ratio derived from the new system are shown to be similar to those from the optical extinction system, previously reported in the literature.

* Deceased.

Corresponding author address: Griffith Morgan, 204 28th St., Boulder, CO 80303.

gmmorgan@ix.netcom.com

Save
Cover Journal of Applied Meteorology and Climatology
Journal of Applied Meteorology and Climatology

  • Ackerman, B., 1974: The partition of liquid water near the freezing level. Preprints, Conf. on Cloud Physics, Tucson, AZ, Amer. Meteor. Soc., 300–327.

  • ——, and N. E. Wescott, 1986: Midwestern convective-clouds, a review. J. Wea. Mod.,18, 87–93.

  • Baumgardner, D., and J. E. Dye, 1982: Cloud Particle Measurement Symposium: Summaries and abstracts. NCAR Tech. Note NCAR/TN-199 + PROC, 103 pp. [Available from UCAR Communications, P.O. Box 3000, Boulder, CO 80307-3000.].

  • Biter, C. J., J. E. Dye, D. Huffman, and W. D. King, 1987: The dropsize response of the CSIRO liquid water probe. J. Atmos. Oceanic Technol.,4, 359–367.

  • Brown, E. N., and R. R. Braham, 1963: Precipitation particle measurements in cumulus congestus. J. Atmos Sci.,20, 23–28.

  • Coulman, C. E., and M. A. Parker, 1982: On the calibration and performance of an instrument for measuring total water mixing ratio in cloud. J. Appl. Meteor.,21, 695–702.

  • Gayet, J. F., M. Friedlander, and J. P. Pinty, 1977: Sur la mesure de la teneur en eau totale des nuages (On the measurement of the total water content of clouds). Sci. Rep. 22, 26 pp. [Available from Lab. Assoc. Meteor. Phys., Université Blaise Pascal/CNRS/OPGC, 24 avenue des Laudais, F-63177 Aubiere CEDEX, France.].

  • Heymsfield, A. J., P. N. Johnson, and J. E. Dye, 1978: Observations of moist adiabatic ascent in northeast Colorado cumulus congestus clouds. J. Atmos Sci.,35, 1689–1703.

  • Kyle, T. G., 1975: The measurement of water content by an evaporator. J. Appl. Meteor.,14, 327–332.

  • Mather, G. K., 1990: Evidence of an accumulation or “big drop” zone. Bull. Amer. Meteor. Soc.,71, 345–348.

  • Morgan, G., 1992: The problem of the measurement of water quantities in cumulus clouds. Proc. WMO Workshop on Cloud Microphysics and Applications to Global Change, Toronto, ON, Canada, WMO Rep. 19, 121–125.

  • ——, and G. K. Mather, 1984: Problems in the measurements of liquid water content in Transvaal clouds. Extended Abstracts, Ninth Conf. on Weather Modification, Park City, UT, Amer. Meteor. Soc., 24.

  • ——, B. J. Morrison, and G. K. Mather, 1989: Measurement of total and condensed water mixing ratios in warm-based cumulus clouds by a jet engine evaporation technique. Theor. Appl. Climatol.,40, 187–199.

  • Roys, G. P., 1963: Airborne instrumentation system for measuring meteorological phenomena inside thunderstorms. Tech. Doc. ASD-TDR-63-231, 59 pp. [Available from Directorate of Flight Test, Aeron. Systems Div., Air Force Systems Command, Wright–Patterson AFB, Ohio, 45433-9907.].

  • ——, and E. Kessler, 1966: Measurement by aircraft of condensed water in Great Plains thunderstorms. Tech. Note 49-NSSP-19, 17 pp. [Available from NOAA/National Severe Storms Lab., 1313 Halley Circle, Norman, OK 73069.].

  • Ruskin, R. E., and W. D. Scott, 1974: Weather modification instruments and their use. Weather and Climate Modification, W. N. Hess, Ed., John Wiley and Sons, 136–205.

  • Smith, P. L., Jr., 1976: Comments on the measurement of water content by an evaporator. J. Appl. Meteor.,15, 189–191.

  • WRC, 1986: Program for Atmospheric Water Supply, Phase 1, 1983–1986. Vol 4: Instruments, techniques and studies. Report to the Water Research Commission by Simpson Weather Associates and Cansas International Corporation. WRC Rep. 133/4/88, 336 pp. [Available from Water Research Commission, P.O. Box 824, Pretoria 0001, South Africa.].

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 1124 547 17
PDF Downloads 84 40 3