Cloud liquid water measurements on the armored T-28: Intercomparison between Johnson-Williams cloud water meter and CSIRO (King) liquid water probe

Feind, RE Detwiler, AG Smith, PL

Re. Feind et al., Cloud liquid water measurements on the armored T-28: Intercomparison between Johnson-Williams cloud water meter and CSIRO (King) liquid water probe, J ATMOSP OC, 17(12), 2000, pp. 1630-1638

33

INGLESE

Article

Earth Sciences

JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY

0739-0572 → ACNP

17

12

2000

1630 - 1638

ISI

0739-0572(2000)17:12<1630:CLWMOT>2.0.ZU;2-X

Comparisons are made between liquid water concentration (LWC) readings obta ined from a Johnson-Williams (J-W) cloud water meter and a King (Commonweal th Scientific and Industrial Research Organisation) liquid water probe, bot h mounted on the armored T-28 research aircraft during penetrations of spri ngtime convective storms in Oklahoma and Colorado. The King probe readings are almost always higher, being up to twice those of the J-W instrument in clouds with narrower cloud droplet spectra. In clouds with broader droplet spectra, the ratio often climbs to three or greater. The King probe respond s partially to drops larger than cloud droplet size, and also to some ice p articles, so its reading can be higher than the cloud LWC present. However, this and earlier comparisons by others indicate that the primary reason fo r this discrepancy is that the J-W probe often underestimates the cloud LWC due to incomplete response to larger cloud droplets. Thus, published studi es involving cloud LWC in convective storms based on readings of the T-28 J -W probe have often overestimated the effects of entrainment and precipitat ion scavenging on depletion of updraft liquid water, particularly in those areas characterized by clouds with broad droplet size spectra.