Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Observations of Polar Low Structure and Intensity Using Temperature and Moisture Retrievals from Polar-Orbiting Satellites  (Polar-Orbiting Satellite Analysis of Polar Lows)

Outline
Polar lows are cyclonic systems several hundreds of kilometers in diameter which form over high latitude oceanic regions during the winter months. Although found in both hemispheres, Northern Hemispheric polar lows are typically larger and more intense than their Southern Hemispheric counterparts. Maximum wind speeds can exceed 30 m s-1, which, along with often heavy precipitation, pose a threat to ships and coastal regions. Because they form over the ocean and decay rapidly upon landfall, polar lows can only be observed on a routine basis using satellite data. This identification is typically done subjectively, using visible or infrared imagery. Using sounding instruments available on polar-orbiting satellites however, an additional objective analysis tool is possible. In this expression of intent, research is proposed to develop objective analysis techniques for polar lows based on polar-orbiting satellite data. This procedure for analyzing polar lows begins with a temperature and moisture profile. Here the ATOVS soundings available from the NOAA series polar-orbiting satellites will be used. The ATOVS algorithm uses both microwave and infrared data. The microwave portion of the retrieval technique is crucial, as microwave radiation penetrates most clouds. The virtual temperature profile is used in the integration of the hydrostatic equation to compute height fields, as well as surface pressure. In this step, model analysis or forecast 100 hPa heights are used as an upper boundary condition. Wind vectors can be derived from the height fields using a balance condition. Some verification of the technique can come from other satellite instruments, such as scatterometers, but a more complete validation must come from in situ measurements. In addition to the NOAA satellites, the NPP satellite will be available (2006 launch), which has an improved microwave instrument, as well as an interferometer for temperature and moisture profiling. An objective analysis technique will permit the monitoring of long term trends in polar low activity, and investigating large scale precursors to the most intense systems. In combination with the VIIRS instrument on the NPP satellite, the analysis technique can be used to apply barotropic instability theory from tropical cyclone research to the inner core of polar lows. This technique has been successfully used for tropical cyclone research, and has been implemented into operations by NOAA’s Tropical Prediction Center. It is anticipated that a similar progression from research to operations could occur in the area of polar lows.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
Polar lows are not currently analyzed in any consistent, objective manner. Clues of their structure and intensity come from their appearance on visible or infrared satellite imagery and the occasional in situ observation. The natural science research proposed here seeks to explore the new frontier of objectively measuring polar low structure and intensity by microwave and infrared satellite data, thus further describing in a quantitative way the current state of the polar environment. Using this technique to monitor polar lows over several years can serve as a measure of change in the polar regions.

What international collaboration is involved in this project?
Although no specific collaboration has been established, contact with the Norwegian Meteorological Institute in Tromsø concerning polar lows (although not specifically this idea) has been made. Initial results will be shared with them. At that point, more formal collaborations with Norway or other countries can be established.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Initial work will focus on the North Atlantic, from the Labrador Sea to the Barents Sea. Of the regions in which polar lows exist, this area has the highest human impact potential. In situ data from other projects will be important for technique development and verification.

Approximate timeframe(s) for proposed field activities:
Arctic: 01/2007-12/2008            
Antarctic: n/a

Significant facilities will be required for this project:
No logistic support/facilities are needed for this research. For the benefit of other IPY participants, a website will be developed in which relevant fields from the objective analysis technique will be displayed.

Will the project leave a legacy of infrastructure?
The proposed research will leave a legacy of a software infrastructure. The initial code development will be for the current NOAA series satellites, but will eventually be applied for use with future polar-orbiting satellites, particularly NPP and NPOESS

How is it envisaged that the required logistic support will be secured?
Own support

The ATOVS data is currently obtained through cooperation with NESDIS. The NPP data will be obtained through cooperation with NESDIS or CIMSS at the University of Wisconsin.

Has the project been "endorsed" at a national or international level?
Yes. Background work for this project is already being funded by NESDIS for NPOESS risk reduction activities and by NASA for the development of a polar wind algorithm.

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?
New

How will the project be organised and managed?
The project will be self-managed. All data and personnel to do the research are currently in place.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
Our project, which will include graduate student participation, will likely lead to improved forecasts of polar lows, which benefits Arctic residents and decision makers. CIRA develops training modules on the use of meteorological satellite data; a polar low module would be added to the topics already covered.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
The data to be used in the proposed research already have management infrastructures in place. The ATOVS data are archived by NESDIS, and the model data are archived by NCEP. CIRA will initially manage any necessary archiving of the developed products.

How is it proposed to fund the project?
NOAA or NSF funds will be sought to perform this research.

Is there additional information you wish to provide?

PROPOSER DETAILS

Pro Wayne Schubert
Department of Atmospheric Science
Colorado State University
Fort Collins, CO
80523-1371
USA

Tel: (970) 491-8521
Mobile: no
Fax: (970) 491-8449
Email:

Other project members and their affiliation