Relative humidity (RH) measurements acquired in orographic wave cloud and cirrus environments are used to investigate the temperature‐dependent RH required to nucleate ice crystals in the upper troposphere, RHnuc(T). High ice‐supersaturations in clear air—conducive to the maintenance of aircraft contrails yet below RHnuc and therefore insufficient for cirrus formation—are not...
A case study of new particle formation in the region downwind of a mesoscale convective system stretching across much of the central United States is presented. Airborne measurements were made of condensation nuclei (CN), cloud particle surface area, water vapor, and other gases. CN concentrations were greatly enhanced above and...
The ambient temperatures and humidities required for contrail formation
and persistence are determined from in situ measurements during the
Subsonic Aircraft: Contrail and Cloud Effects Special Study (SUCCESS) experiment.
Ambient temperatures and water vapor concentrations were measured
with the meteorological measurement system, a laser hygrometer, and a cryogenic
hygrometer (all...
During the Tropical Composition, Clouds and Climate Coupling (TC4) experiment
that occurred in July and August of 2007, extensive sampling of active convection in the
ITCZ region near Central America was performed from multiple aircraft and satellite
sensors. As part of a sampling strategy designed to study cloud processes, the...
The concentrations of atmospheric gases and condensation nuclei (CN) or aerosol in
the outflow of a storm were measured aboard a NASA DC-8 aircraft, as described in a
companion paper [Twohy et al., 2002]. The data are used here to study the production of
the aerosol. Major fluctuations in CN...