A counterflow virtual impactor (CVI) designed for aircraft use was evaluated at the NASA Icing Research Tunnel in Cleveland, Ohio. Tests were conducted for tunnel speeds of 67 and 100 m s⁻¹, for liquid water contents of 0.23–1.4 g m⁻³, and for a wide range of droplet median volume diameters...
The southeast Pacific Ocean is covered by the world's largest stratocumulus cloud layer, which has a strong impact on ocean temperatures and climate in the region. The effect of anthropogenic sources of aerosol particles on the stratocumulus deck was investigated during the VOCALS field experiment. Aerosol measurements below and above...
The effective radius (r[subscript]e) is a crucial variable in representing the radiative properties of cloud layers in general circulation models. This parameter is proportional to the condensed water content (CWC) divided by the extinction (σ). For ice cloud layers, parameterizations for r[subscript]e have been developed from aircraft in situ measurements...
At low latitudes, cirrus are ubiquitous and can be in
excess of 100°C colder than the surface, limiting the
amount of sunlight absorbed by the earth’s atmosphere and
surface, and reducing its loss of heat. Here we present
aircraft measurements within cirrus over southern Florida
indicating that ice crystals have...
The first reliable aircraft measurements of characteristic cloud drop charges were obtained by utilizing a counterflow virtual impactor to substantially increase charge sensitivity and eliminate spurious contact charging that contaminated previous aircraft measurements. We find average drop charges more than an order of magnitude larger than expected from mountain surface...
Many investigations using satellite data have determined that aerosol optical depth and cloud cover are correlated and some have interpreted the correlation as evidence of an aerosol indirect effect on clouds. This study uses in situ aircraft observations taken during the Indian Ocean Experiment (INDOEX), February–March 1999, and mostly over...
Lenticular wave clouds are used as a natural laboratory to estimate the linear and mass growth rates of ice particles at temperatures from -20° to -32°C and to characterize the apparent rate of ice nucleation at water saturation at a nearly constant temperature. Data are acquired from 139 liquid cloud...
This two-part study attempts to find appropriate mass dimension and terminal velocity relationships that,
when considered together with particle size distributions (PSD), agree with coincident measurements of ice
water content (IWC), and with variables related to higher moments such as the mean mass-weighted fall
speed. Reliable relationships are required for...