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Atmospheric modeling in ProClim by Anne D. Sandvik. TITLE OF PRESENTATION by N.N. ProClim, WP 2: Water mass formation on shelves. Atmospheric modeling.
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Atmospheric modeling in ProClim by Anne D. Sandvik TITLE OF PRESENTATION by N.N.
ProClim, WP 2: Water mass formation on shelves • Atmospheric modeling ”Perform nonhydrostatic 1-2 km resolution model studies of Storfjorden and the westernBarents Sea, and make the atmospheric model available for coupling to the ice-ocean model”
Motivation • HINDCAST wind (75 km) and observations from Hopen • High-resolution model estimated wind • Impact on the circulation and Polynia dynamics due to resolution in the wind forcing? • Coupled ice-ocean-atmospheric model
Preliminary workplan: • 4 km atmospheric forcing 1998-1999 (Ragnheid, MM5 -> BOM) • Validation against synoptic observations, 2003 • Case study polar low, March 11, 2003 • Sensitivity to ice cover (in Storfjorden) • MM5 - ROMS
MM5, NCAR/Penn State mesoscale model • Non – hydrostatic • Polar mode • 23 vertical sigma level (40m – 15 km) • One way nesting 12 -> 4km • Initial and lateral boundary values (ECMWF)
Observations from met.no • Ny-Ålesund • Longyearbyen • Hopen Model domain: 12 -> 4 km ( BOM)
The synoptic weather station at Hopen is located beneath a gapor pass in the mountain at the eastern side of the island.The station elevation is about 10 m. Hopen is about 33 km long and 1,5 - 2 km wide and its orientation on the map is SSW – NNE. Due to the local topography wind measurements are probably tolow when the wind direction are from SW (220) and clockwisethrough west (40-60), with a possibly small secondary maximumwhen the wind direction are from west and the flow comes through the gap. Wind observations, Hopen 1998 – 1/9 2002 • Hopen is not represented in the MM5 4 km domain
Temperature at Hopen, observation 2 m asl (red line) and model estimated temperature about 38 m agl (blue line). The mean value and standard deviation of the observations are indicated with the green and black dashed lines respectively. MM5 estimated temperature and wind • 1/8 – 1/12, 1998 • 1/1 – 1/5, 1999
Wind speed, Hopen Wind speed at Hopen, observation 10 m asl (red line) and model estimated wind about 38 m agl (blue line). The mean value and standard deviation of the observations are indicated with the green and black dashed lines respectively.
Hopen – Storfjorden, Sep., 1998 Model estimated temperatur and wind at Hopen (red line) and at a positipninside Storfjorden (blue line) How representative is Hopen for the Storfjorden area?
Hopen – Storfjorden, Sep., 1998 Correlation coefficient for temperature (left) and wind speed (right) estimated between the MM5 Hopen gridpoint and all other gridpoints in the 4 km domain.
Hopen – Storfjorden, Sep., 1998 Correlation coefficient for wind direction estimated between the MM5 Hopen gridpoint and all other gridpoints in the 4 km domain.
BOM with HINDCAST wind (75 km) • BOM with MM5 wind, Ragnheid Summary subtask 1 • Hopen obs – Hopen MM5 • Hopen MM5 – Storfjorden MM5
Validation of MM5 against available data in Arctic, March 2003 • Temperature, wind speed and direction: • Hopen • Longyearbyen • Ny-Ålesund
Observations from NMI • Ny-Ålesund • Longyearbyen • Hopen Model domain: 12 -> 4 km
MM5 estimated wind Wind, 9/3 – 03, 1200 UTC ECMWF interpolated to 4 km MM5 domain
Temperature, March 2003 Temperature at Hopen, observation 2 m asl (blue line) and model estimated temperature about 38 m agl (red line). The mean value and standard deviation of the observations are indicated with the green and black dashed lines respectively.
Wind speed, March 2003 Wind speed at Hopen, observation 10 m asl (blue line) and model estimated wind about 38 m agl (red line). The mean value and standard deviation of the observations are indicated with the green and black dashed lines respectively
Wind speed and direction, March 2003 Wind roses for March 2003, observations in the left panel and ”MM5 Hopen” in right panel. The direction is divided into 24, 15 deg bins. The numbers on the inner and outher circle show the % at the given direction. Blue shows wind speeds from 0 – 5 m/s, pink from 5 – 10 m/s and yellow from 10 – 15 m/s.
Work in progress: • Case study polar low, March 11, 2003 • Sensitivity to ice cover • Atmospheric boundary layer over ice • Method for picking interesting cases from ERA-40
Work in progress: • MM5 -> BOM • MM5 -> ROMS(ICE) -> MM5 -> ROMS(ICE) Input?