Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Local and long-range interactions of polar mesocyclones  (Polar mesocyclones)

Outline
Polar mesocyclones are small-scale (often of order a few hundred kilometres) and often rapidly developing polar storms that can be associated with high-impact weather such as strong surface winds and snowfall. Their small scale and location in sparsely observed regions has meant that climatological studies have been restricted to subjective identification techniques (such as identification from satellite images). Polar mesocyclones may have a significant influence beyond the arctic polar region, both through the triggering of larger-scale mid-latitude cyclones that affect Europe and through their possible influence on the ocean’s thermohaline circulation. In this project ECMWF operational analyses will be used to derive a five-year climatology of polar mesocyclones that originate in the Nordic Seas (defined as the North Atlantic east of Greenland and north of 60°N, plus the North Sea, the Norwegian Sea, the Greenland Sea and the Barents Sea). This data is available at 6 hourly temporal resolution and, in recent years, at sufficiently high spatial resolution (0.5 degrees). Re-analysis datasets are not suitable for this study due to their poorer spatial resolution. A well-established tracking algorithm (Hodges, 1994) will be modified to identify polar mesocyclones and determine tracks. Once validated against satellite and synoptic data, objective track statistics will be produced. The objective lifecycle climatology will enable us to address several key questions. Strong ocean to atmosphere heat fluxes occur in convective polar mesocyclones which can initiate deep oceanic convection and may influence the thermohaline circulation. The regions where these occur will be inferred from track density statistics. The possible transition of polar mesocyclones into mid-latitude frontal cyclones, known as ‘instant occlusion’ events, and hence their impact on the weather of North-West Europe will be assessed through track analysis. The relationship of the genesis regions of polar mesocyclones with factors such as orography and low-level baroclinicity associated with sea-ice edges will be determined. A strong relationship would imply possible sensitivity to climate changes. Factors that lead to the development of the most intense polar lows will be assessed from model diagnostics. Regional climate modelling using the Met Office Unified Model will be used to produce a high resolution (~50 km), 30-year climatology of winter polar mesocyclones. This will be validated against the shorter-period climatology derived from analysis data. This longer climatology will enable the relationship between track statistics and multi-year climatic fluctuations such as the North Atlantic Oscillation to be determined.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
1. Characterisation of the interaction of polar mesocyclones with the Arctic environment though coupling with the ocean and the role of ice-edges and orography in their genesis. 2. Characterisation of the interaction between Arctic and the midlatitudes through polar mesocyclones by their transition into midlatitude cyclones and their variability with climate indices. These anticipated advances explore interactions between polar regions and the rest of the globe (consistent with IPY-theme 3). They are timely given recent improvements in the spatial resolution of models that are essential for the development of the new objectively defined climatology of polar mesocyclones. This will enable previously unexplored scientific questions to be addressed.

What international collaboration is involved in this project?
Collaboration with Eric Kolstad at the Bjerknes Center regarding regional climate simlations. Strong National collaboration with the (U.K.) Met Office, with the Environmental Systems Science Centre at the University of Reading, and through the Universities Weather Research Network (UWERN)is also anticipated.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Not applicable

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: n/a

Significant facilities will be required for this project:

Will the project leave a legacy of infrastructure?

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

Has the project been "endorsed" at a national or international level?
Not at this stage.

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?
Progress is envisaged through the relatively small investment of funding for a postdoctoral researcher who will be directly supervised by the principal investigator with collaboration with other researchers in this field. This project will thus enhance the development of the next generation of polar researchers. The management requirements of this focused project are thus minimal.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
Plans for education, outreach and communication of activities to other communities are under development.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
It will be considered whether it is appropriate to make the output of the regional climate simulations of the Nordic seas region available to the community through the BADC (British Atmospheric Data Centre).

How is it proposed to fund the project?
The U.K. Natural environment research council (NERC) has announced a new 5.3 million pound funding initiative called Artic-IPY. Researchers expecting to respond to this initiative have been requested to submit this IPY Expression of Intent.

Is there additional information you wish to provide?
This project proposal was developed jointly with Tom Bracegirdle, a current PhD student of the lead contact for this project. Tom has already developed a short-term climatology of polar mesocyclones from Met Office Unified Model data. However, this climatology does not include track statistics as the data has insufficient temporal resolution. Tom is keen to pursue a career in polar research. This project is also consistent with the proposed linkage between THORPEX activities and IPY, in particular in its aim to address high-impact weather events and processes associated with polar and subpolar interactions.

PROPOSER DETAILS

Dr Suzanne Gray
Department of Meteorology, University of Reading
Earley Gate
Reading
RG6 6BB
UK

Tel: 441183786791
Mobile: no
Fax: 441183788905
Email:

Other project members and their affiliation