- Director's Message
- Table of Contents
- Strategic Goals: Science, Facilities & Technology
- 1. Exploring atmospheric, Earth system, and solar processes, variability, and change
- 2. Investigating the interaction of the atmosphere, the broader Earth system, and human society
- 3. Improving prediction of weather, climate, and other atmospheric phenomena
- 4. Developing community models
- 5. Enabling innovative field experiments and measurement campaigns
- 6. Developing new instrumentation
- Research Catalog
Carl Schmitt
General Information
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MMM - TIIMES
Associate Scientist
Water System - UTLS
Contact Information:
PO Box 3000, Boulder, CO 80307-3000
Office: FL3 - 3034
Telephone: 303-497-8905
Email: schmittc@ucar.edu
Home Page - Vita
Research Focus FY08:
The bulk of my TIIMES research has been spent researching the properties of tropical cirrus cloud microphysical data from aircraft field projects. The properties of tropical cirrus cloud particles are important for a better understanding of Upper Troposphere/Lower Stratosphere (UTLS) water vapor exchange as well as for radiative transfer applications.
We have been working on data from the Video Ice Particle Sampler Probe* (VIPS) taken during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE: EOL Project page - NASA page - photo gallery) and Pre-Aura Validation Experiment** (Pre-AVE) field programs during time periods when the aircraft was in thin tropical cirrus. Our data analysis is focused on better understanding the fall speed and mass dimensional properties as they relate to climate model parameterizations. Mass weighted fall speeds calculated from the terminal velocity estimates and particle size distributions indicate that GCM parameterizations over estimate fall speeds. The fall speeds of sub-visible cirrus clouds is particularly important as slower fall speeds leads to longer cloud lifetimes. We are also working on laboratory measurements that will enable us to make better estimates of the mass of very small ice crystals similar to those observed in the UTLS cirrus.
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* Video Ice Particle Sampler: An aircraft-mounted instrument which first collects cloud particles then images them and records them on videotape. It has collected ice particles as small as 5 microns and is an important complement to the 2D-C imaging probes which provide information on much larger particles. Provides unique and important means of assessing cloud microphysical composition with the accuracy and resolution necessary to consider crucial questions relating to the role of clouds in affecting global climate.
** Pre-AVE: (Pre Aura Validation Experiment) occurred in January - February 2004 in Costa Rica, sponsored by NASA. It has produced some key data about water and clouds in the tropics.
Scientific Talks FY08:
- International Conference on Clouds and Precipitation (Cancun, Mexico, July 2008)
- UTLS/START08 Cirrus Cloud Properties (Boulder, Colorado, August 2008)
Publications FY08 (abstract):
Schmitt, C. G., A. J. Heymsfield, 2007: On the occurrence of hollow bullet rosette- and column-shaped ice crystals in midlatitude cirrus. J. Atmos. Sci., 64, 4514-4519, doi: 10.1175/2007JAS2317.1.