Dr. Jordan G. Powers

Mesoscale and Microscale Meteorology Division

NCAR Earth System LaboratoryNational Center for Atmospheric

Research Boulder, CO

WMO THORPEX Polar Prediction WorkshopOslo, Norway

October 6, 2010

Antarctic Weather Prediction Antarctic Weather Prediction Activities— USAActivities— USA

Polar Numerical Weather Prediction— United States

• Arctic and Antarctic Regions

• NWP Operations

– NCEP (National Centers for Environmental Prediction)

▪ GFS: Global Forecasting SystemT574 (27 km)8-d forecasts

▪ Arctic latitudes

NAM: North American Mesoscale model

12-km grid4-day forecasts

Alaska Hi-Res Window (HRW): 5-km WRF-ARW

Polar Numerical Prediction— US

• NWP Operations (cont’d)

– High–latitude NAM and Hi-Res Windows (HRW)

Alaska HRWNAM

Polar Numerical Prediction— US

• NWP Operations (cont’d)– U.S. Air Force Weather Agency

▪ Arctic and Antarctic mesoscale forecasting: WRF▪ Forecast distribution restricted

– U.S. Navy ▪ NOGAPS: Navy Operational Global Atmospheric Prediction System

▪ Limited public products available (unclassified)

NOGAPS 300 hPa height, winds: 24-h fcst24 Sept 2010 1200 UTC init

Polar Numerical Prediction— US

• NWP Operations (cont’d)

– AMPS: Antarctic Mesoscale Prediction System

▪ Forecasts for Antarctica and high southern latitudes

▪ Forecasts for

U.S. Antarctic Program forecasters (primary)

Researchers, international users (secondary)

– AMPS: The Antarctic Mesoscale Prediction System

▪ Real-time NWP system to support Antarctic forecasting and science

▪ Forecasts for Antarctica and high southern latitudes

▪ Sponsor: National Science Foundation, Office of Polar

Programs

▪ Collaborators NCARThe Ohio State UniversityUniv. of Colorado

Polar Numerical Prediction— United States

• NWP Operations (cont’d)

• History– Antarctic Weather Forecasting Workshop

(2000) (Byrd Polar Research Center, Ohio State Univ.)

– Recognized weaknesses in Antarctic NWP

▪ Inadequate horizontal resolutions for capturing mesoscale features

▪ Inadequate representation of physical properties unique to Antarctic troposphere and PBL

▪ Poor representation of Antarctic topography

– Recommendation: Need for a robust, high-resolution NWP system tailored to the needs of the forecasters at McMurdo

The Antarctic Mesoscale Prediction System (AMPS)

• AMPS Users / Applications

– Primary: USAP Forecasters: Space and Naval Warfare Systems Center (SPAWAR)

– Researchers and graduate students

– Support for international on-Ice activities

– Scientific field experiments

Examples:

LARISSA campaign (2010)(Larsen Ice Shelf System,

Antarctica)

MaudNESS study (2005; R/V cruises)

(Dronning Maud Land Nonlinear Equation of State System)

GLOBEC Study(Global Ocean Ecosystem Dynamics)

The Antarctic Mesoscale Prediction System (AMPS)

1.67 km

15 km

5 km

5 km

5 km

● McMurdo

45 km

15 km

Christchurch

South Pole

●

●

McMurdo Station

AMPS Model: WRF – Weather Research and Forecasting Model

– “Polar WRF”: WRF w/modifications for polar regions

Forecast Domains: 45-/15-/5-/1.67-km

McMurdo

Ross Is.

• Vertical configuration– 44 η-levels

– 10 mb top

• Frequency– 2 forecasts / day

– 0000 UTC, 1200 UTC initializations

• Lengths

– 45-km, 15-km grids: 120 hr

– 5-km, 1.67-km grids: 36 hr

• First-guess/BCs: GFS

AMPS Forecasts

Model EnhancementsAntarctic topo: 200-m RAMP2 dataset

(Radarsat Antarctic Mapping Project)

Cycled soil temperatures

Dry Valleys land use

1.7-km Grid Land Use (brown=bare ground)

USGS map: Ross Is., Dry Valleys

RAMP2 – USGS terrain hgts (m)

Data Assimilation

WRFDA (3DVAR) system: 45- and 15-km grids

Assimilated observations includeConventional obs (radiosonde, AWS, ship, buoy, aircraft,

METAR)Satellite (e.g., SATOB, GEO & MODIS AMV, QuikSCAT, AMSU-A rads)GPS RO (refractivity— COSMIC)

Soundings COSMIC

Selected Obs: 0000 UTC 20 Sept 2009

• Location: NCAR

• IBM Power 6 architecture

• 3 32-processor Nodes

96 CPUs 4.7 Ghz

processors

• Wallclock time/fcst

4.5 hr

• Funding: National Science Foundation

AMPS: Computer Platform

62nd Airlift Wing C-17Ice Runway, McMurdo

New York Air National Guard LC-130 Ice Runway, McMurdo

AMPS provides numerical guidance for SPAWAR forecasting forthe USAF, NYANG, Royal New Zealand AF, and other on-Ice air ops (e.g., helicopters, Twin Otters).

AMPS— Antarctic Air Support

AMPS: International Support

Italy Australia UK Germany South Africa Chile China New Zealand DROMLAN Group— Dronning Maud Land Air Network

Germany, Russia, India,

Japan, Norway, Sweden, Finland, Belgium, UK, South Africa

SA Agulhas (South Africa)(background)

RV Polarstern (Germany)(foreground)

Site: www.mmm.ucar.edu/rt/amps

Forecast Grid Product ChooserModel RunFcst hr

AMPS Display Page

Run Status

SLP3-h Precip

17 Sept 20101200 UTC init

Fcst period: 12 UTC 17 Sept–12 UTC 22 Sept

AMPS Forecast Products

Meteogram–South Pole

17 Sept 20101200 UTC init

Fcst period: 12 UTC 17 Sept–00 UTC 19 Sept

AMPS Forecast Products

NZSP South Pole (lat, lon) = (-90.00, 0.00)Forecast initialized at 2010091712AMPS 5-km SP domain FCST UTC T Tcorr Td Altim Spd Dir Grid VVV RH1RH2RH3 T1T2T3 ACCUMHR HR (C) (C) (C) (in.) (kts) (°) (°) (% wrt water) (C) 00 12 -63.9 -63.7 -51.5 28.42 11 41 41 -007 469078069 M53M42M39 000 01 13 -61.2 -62.1 -65.9 28.41 12 104 104 -008 054065068 M50M43M39 002 02 14 -57.3 -58.6 -61.8 28.38 15 91 91 -010 056066069 M48M41M38 002 03 15 -54.7 -56.0 -59.2 28.41 15 82 82 -010 057066069 M46M40M37 002 04 16 -52.9 -54.0 -57.4 28.39 12 72 72 -006 058066069 M45M40M37 002 05 17 -47.8 -49.0 -52.1 28.34 13 39 39 -003 061066069 M44M40M37 003 06 18 -45.6 -47.1 -49.8 28.35 16 23 23 -004 063067069 M43M39M37 003 07 19 -44.8 -46.0 -48.9 28.32 17 21 21 -005 063068069 M41M37M36 003 08 20 -44.3 -45.6 -48.5 28.34 17 22 22 -006 063068069 M41M37M36 002 09 21 -43.9 -45.1 -47.9 28.36 17 22 22 -006 064068069 M40M37M36 002 10 22 -43.2 -44.3 -47.2 28.33 18 19 19 -006 064068068 M40M37M36 002 11 23 -42.9 -44.1 -46.9 28.36 17 18 18 -006 064068068 M40M38M37 002 12 00 -42.8 -44.1 -46.9 28.38 17 15 15 -005 064068068 M40M38M37 002 * NOTES on units: VVV (vertical velocity) in tenths of a microbar per second at 700 hPa (positive– upward motion) ACCUM (accumulated precipitation, past 1h) is given as hundreths of a millimeter; RH1, RH2, and RH3 are the % RH at the surface, 1000', and 3000', respectively; T1, T2, and T3 are the temperatures at 500', 1000', and 1500', respectively.

Table– South Pole

AMPS Forecast Products

AMPS Archive• AMPS Forecasts Stored

– NCAR Mass Storage System

– MM5 and WRF forecast output Native model format GRIB subsets of output (Oct. 2008)

▪ Select fields (e.g., u, v, T, GHT) ▪ Mandatory and some selected levels

– Forecast plots (Oct. 2008)

• Applications

– Model verification and forecast review

– Case and process studies

– Site and region climatologies

Information: www.mmm.ucar.edu/rt/wrf/amps/information/archive_info.html

• US Polar NWP: – Military: Arctic & Antarctic— Restricted

access

– Civilian: Arctic— NCEP

Antarctic— NSF: AMPS Group

• AMPS: Antarctic Mesoscale Prediction System

– Real-time NWP guidance: WRF model

– Support to: USAP weather operations Research Field campaigns International community Emergency operations

– Funding: U.S. National Science Foundation Office of Polar Programs

Summary