Antarctic Regional Interactions Meteorology Experiment (RIME) Antarctic Regional Interactions Meteorology Experiment (RIME) David H. Bromwich 1, John J. Cassano 2, James Pinto 2,3, and James Moore 4 1 -Ohio State University 2 -University of Colorado Boulder 3 -NCAR Atmospheric Technology Division 4 -UCAR Joint Office for Scientific Support Outline Key science questions Approaches to address key science questions Timeline Budget aspects Discussion topics

The Overarching Hypothesis: The Ross Sea region is critical in the transport of mass, heat and momentum between the Antarctic continent and lower latitudes of the Southern Hemisphere on a variety of scales.

Figure 2.1. Mean streamlines of the wind at approximately 10-m above the surface based on daily MM5 simulations from 15 June – 15 July Surface interactions with middle latitudes (Courtesy Thomas R. Parish) Ross Ice Shelf Air Stream (RAS) Siple Coast Circumpolar Vortex Byrd Glacier Terra Nova Bay

Mass loss from Antarctica primarily via the Ross Sea Sector has hemispheric impact Parish and Bromwich (1998) (Zonal average includes all longitudes)

Surface Pressure DifferenceSurface Temperature Difference Tropical teleconnections: Late 1990s El Nino minus La Nina **The Ross Sea is a center of action (Bromwich et al. 2004)

Specific science topics Boundary-Layer Structure and TransformationBoundary-Layer Structure and Transformation Local Moist Atmospheric ProcessesLocal Moist Atmospheric Processes Mesoscale CyclonesMesoscale Cyclones Terrain-Induced CirculationsTerrain-Induced Circulations Moist Processes and Cyclonic EventsMoist Processes and Cyclonic Events Circumpolar VortexCircumpolar Vortex Hemispheric InteractionsHemispheric Interactions Antarctica Ross Ice Shelf South Pacific Ocean Rising motion due to cyclones Katabatic Winds RAS = Katabatic + Barrier Winds Southward Return Flow Sinking Branch Polar Direct Circulation over Antarctica: Emphasizing the Ross Sea How do these topics relate to climate?

Approaches to address science questions Investigation Approaches Regional Surface- Based Array RIME Supersite Aircraft StudiesModeling Satellite Remote Sensing Climate Studies Small scale Boundary Layer Structure and Transformation xxxx Local Moist Atmospheric Processes xxxxx Mesoscale Cyclones xxxxx Terrain- Induced Circulations xxxx x Moist- Processes and Cyclonic Events x xxxx Circumpolar Vortex x xxxx Science Topics Large scale Hemispheric Interactions xxxx

RIME Field Sites: RIME Supersite Planned AWS sites Planned radiosonde sites New AWS sites Existing research stations Ice Shelf Edge South Pole traverse route 500 km

Ross Ice Shelf MG Pattern Meso Raster RAS MG Pattern Local Raster Glacier Pattern Aircraft flight track schematics showing regional and local scale sampling strategies. Long distance/duration C-130 and HIAPER flights to address local and regional process studies. Mapping of local airflow components and RAS accomplished with C-130, Aerosondes and twin otters. (sawtooth, glacier pattern, local raster, meso raster and MG pattern). Aircraft measurements will complement simultaneous Supersite, special AWS and sounding measurements in the region. RIME Aircraft Activities to address key phenomena and scale interactions: Supersite

Timeline: RIME Field Activities and Science Topics Circumpolar Vortex Terrain-Induced Circulations Moist Processes and Cyclonic Events Mesoscale Cyclones Boundary Layer Local Moist Processes 2005/ / / /2009 International Polar “Year” (Red)(Blue) Why 3 Field Seasons?: 2006/2007 season is the first field deployment related to the Supersite and will be a shakedown period. Similarly, this is the first field deployment for the U.S. Twin Otter and Aerosondes. Activities will be concentrated near McMurdo (local activities). 2007/2008 season is when local scale studies are expanded to the Ross Ice Shelf and north of Ross Island. 2008/2009 season expands to regional focus. This will be facilitated by the C-130 and HIAPER Hemispheric Interactions

Year:04/0505/0606/0707/0808/0909/? Regional Surface-Based Array – RIME Supersite– Aircraft Studies – Modeling.3.5 Satellite Remote Sensing–.5 – Climate Studies--.5 Support (e.g., RPO mtgs, data mgmt) Total RIME Budget Estimates by Observation Type/Discipline (Estimate in Millions of $) Assumptions: Supersite continuous ops FY07-09 U.S. Twin Otter “provided” by USAP Polar C-130 deployment cost only HIAPER aircraft funneled through NSF deployment pool 2009/10 and later resources for analysis activities Current Funding: Parish and Cassano: RAS Study ~150 K/y Kuo et al. – Data Assimilation ~250 K/y

Discussion Topics The likely future funding profile for the RIME project. As we have seen, the project requires resources far in excess of the normal budget for Polar Oceans and Climate Systems. Consideration of submission deadline delay for RIME proposals (July 1, 2004)? What is the best way to coordinate proposals? Are individual or collaborative approaches preferred? Discussion of aircraft platform requirements for RIME. Building and maintaining the Supersite. Need for RIME-SMO (RIME Science Management Office) and responsibilities. Intl collaborations, (e.g., UK, Italy, etc), to improve RIME observational network and help answer key science questions.