A new research aircraft for the documentation of the impacts of pollution aerosols on clouds and precipitation

Axisa, Duncan SOAR
Collins, Don Texas A&M University
Rosenfeld, Daniel
Woodley, William

Category: Radiation

The importance of aircraft in situ measurements is well demonstrated by the progress that these data helped to achieve over the last two decades. Advances were quite spectacular over this period both in aircraft capabilities and in the instrumentation carried by them. Through the years new aircraft probe designs have evolved. These improvements provide an extended and overlapping size range of cloud particles and accumulation mode aerosol measurements. Improved electronics provide better resolution, particle sizing and accurate particle concentrations. Seeding Operations & Atmospheric Research (SOAR) has recently equipped a Piper Cheyenne II with the newest instrumentation available commercially. The SOAR research aircraft is equipped with a combination of aerosol and cloud droplet spectrometers, in addition to a Cloud Condensation Nucleus (CCN) counter operating at a supersaturation as low as 0.1%.

This poster introduces the SOAR research aircraft to the Atmospheric Radiation Measurement (ARM) community with a description of the instrumentation platform carried on this aircraft. Specific analysis from case studies using data collected from the airborne platform during five field deployments within the last 19 months will be discussed to highlight the capabilities of the SOAR research aircraft.

The in-situ measurements to be presented from the five field campaigns are:

1. In situ aircraft measurements of the cloud microstructure validated satellite retrievals of cloud particle effective radius and microphysical phase (SUPRECIP 1).

2. Aircraft measured diurnal evolution of aerosols, cloud drop size distributions and precipitation processes in post-frontal orographic clouds over the Sierra Nevada (SUPRECIP 2).

3. Documentation of the vertical evolution of cloud drop size distribution and precipitation in convective clouds and its dependence on CCN spectra (SPECTRA 1).

4. Unambiguous hygroscopic seeding signatures having the form of low concentrations of anomalously large (> 30 micron diameter) cloud drops (SPECTRA 2).

5. CCN concentrations immediately downwind of Houston under southerly flow conditions were observed to be as much as 10 times higher to the north than those measured on the east, west, and south sides of the Houston urban plume (HEAT).

The SOAR research aircraft team has as its mission to improve the scientific understanding of the fundamental physics related to pollution aerosol impacts on clouds and precipitation and to improve the capabilities of atmospheric research aircraft with new and modern instrumentation. SOAR is committed to work with the leading scientists in this field while offering its professional capabilities efficiently and cost effectively. Access to the SOAR research aircraft is offered to all research groups. The facility is offered with the configuration required, including infrastructural, logistical, technical and scientific support

This poster will be displayed at the ARM Science Team Meeting.