| NSF Org: |
AGS Division of Atmospheric and Geospace Sciences |
| Recipient: |
|
| Initial Amendment Date: | December 8, 2011 |
| Latest Amendment Date: | January 16, 2014 |
| Award Number: | 1104642 |
| Award Instrument: | Continuing Grant |
| Program Manager: |
Nicholas Anderson
nanderso@nsf.gov (703)292-4715 AGS Division of Atmospheric and Geospace Sciences GEO Directorate for Geosciences |
| Start Date: | January 1, 2012 |
| End Date: | December 31, 2016 (Estimated) |
| Total Intended Award Amount: | $374,112.00 |
| Total Awarded Amount to Date: | $374,112.00 |
| Funds Obligated to Date: |
FY 2013 = $94,013.00 FY 2014 = $100,144.00 |
| History of Investigator: |
|
| Recipient Sponsored Research Office: |
3100 MARINE ST Boulder CO US 80309-0001 (303)492-6221 |
| Sponsor Congressional District: |
|
| Primary Place of Performance: |
3100 MARINE ST Boulder CO US 80309-0001 |
| Primary Place of
Performance Congressional District: |
|
| Unique Entity Identifier (UEI): |
|
| Parent UEI: |
|
| NSF Program(s): | Physical & Dynamic Meteorology |
| Primary Program Source: |
01001213DB NSF RESEARCH & RELATED ACTIVIT 01001415DB NSF RESEARCH & RELATED ACTIVIT |
| Program Reference Code(s): |
|
| Program Element Code(s): |
|
| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.050 |
ABSTRACT
Combined influences of water vapor, ozone, aerosols and cirrus clouds in the upper-troposphere/lower-stratosphere (UTLS) region serve to strongly modulate radiative forcing of the earth's climate system. The composition of this region is affected not only by chemical processes, but also by dynamical ones such as cross-tropopause exchange and convective transports originating near the earth's surface. The Deep Convective Clouds and Chemistry (DC3) field campaign, to be conducted May-June 2012, will support study of the contrasting impacts of continental midlatitude thunderstorm systems on UTLS composition and chemistry within three regions (viz. northeastern Colorado, western Oklahoma and Texas, and northern Alabama) characterized by differing background chemistry and characteristic storm behavior. This award will support adaptation of an existing tunable diode laser-based instrument, the University of Colorado closed-path laser hygrometer, to make measurements of total water (from which condensed liquid and ice water contents may be derived) aboard the NSF/NCAR GV research aircraft during DC3. A new inlet specific to the selected sampling location aboard the GV will be designed and built in collaboration with a consultant from Embry-Riddle Aeronautical University to enable accurate sampling of a wide range of cloud particle sizes (10-400 micrometers).
The intellectual merit of this research rests on provision of precise and accurate measurements of total water at high spatial resolution within the upper reaches of midlatitude convective cloud systems, which will in-turn allow investigators to describe differing transport properties of shear-driven vs. airmass-type thunderstorms, their attendant evolving microphysical properties over cloud lifecycles, and how anvil radiative environments differ from region to region and with time during the interval 12-48 hours after cessation of active convection. Broader impacts will include graduate student training and public outreach, but will ultimately extend to improved understanding of controls on atmospheric ozone and associated links to climate assessment and policy formulation.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
Note:
When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external
site maintained by the publisher. Some full text articles may not yet be available without a
charge during the embargo (administrative interval).
Some links on this page may take you to non-federal websites. Their policies may differ from
this site.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
A new laser-based instrument to measure cloud-water was developed and flown on the Gulfstream-V National Science Foundation aircraft during multiple field campaigns. By rapidly warming the air sampled by a foward-facing inlet, the instrument evaporates water and subsequently measures the total amount of water vapor, allowing for the determination of the amount of condensed water in clouds. This quantity is important for understanding cloud formation, precipitation, and interactions of clouds with visible and infrared radiation. In conjunction with other observations, the results of these studies allow for the identification and characterization of different types of particles in clouds. For example, in one publication it was shown that at the tops of thunderstorms there is a type of particle called a "frozen droplet aggregate", essentially a twisted, long chain of droplets that stick together upon freezing, a process that is faciltated by electric charges created by lightning in thunderstorms. In addition to the observations in and around thunderstorms in the continental United States, observations were obtained in the Southern Hemisphere near Antarctica in "mixed-phased clouds," or clouds containing both liquid and frozen water in the same space. These clouds are particularly difficult to model; therefore, observations directly within them help to constrain models that are used to predict the impacts of such clouds on precipitation and energy exchange near the earth's surface. Finally, we were able to obtain the first observations of cloudwater contents from a research aircraft flying over a highly polluted region in the western Pacific Ocean. These observations will allow future studies into the role of natural and human-caused sources of particulates on cloud properties. Specifically, there is an interest in quantifying a phenomenon called the "aerosol indirect effect," or how particle enhancements supress the sizes of cloud droplets which in turn reduces precipitation back to the surface. Studies such as these are useful for determining the impact of air pollution on rainfall patterns, something that is important for agriculture as well as human health.
Last Modified: 03/31/2017
Modified by: Darin W Toohey
Please report errors in award information by writing to: awardsearch@nsf.gov.
