Fine structure of a Greenland reverse tip jet: a numerical simulation

Article English OPEN
Ohigashi, Tadayasu ; Kent Moore, G. W. (2009)
  • Publisher: Co-Action Publishing
  • Journal: Tellus A (issn: 1600-0870, eissn: 0280-6495)
  • Related identifiers: doi: 10.3402/tellusa.v61i4.15607
  • Subject:
    arxiv: Physics::Geophysics | Physics::Atmospheric and Oceanic Physics | Astrophysics::High Energy Astrophysical Phenomena

Reverse tip jets are strong low-level winds with easterly component that form near the southern tip of Greenland. In the present study, a reverse tip jet case which occurred from 21 to 22 December 2000 was examined to clarify its fine structure using a numerical model with a horizontal resolution of 3 km. The reverse tip jet, showing the supergeostrophic wind speed with a maximum wind speed in excess of 45 m s−1, extended from the east coast of Greenland to the west of Cape Farewell with anticyclonic curvature. A cloud free region coincided with the jet indicated that there was a mesoscale downdraft. Along the eastern edge of the jet, a banded cloud formed between the upstream easterly wind and the colder northerly wind that is a part of the jet and is located along the east coast. This cloud was associated with large gradients in surface wind speed, temperature, moisture, and heat flux. A maximum surface total heat flux of 300 W m−2 coincided with the location of the jet. It is suggested that the orographic deflection by Greenland’s large-scale topography as well as small-scale downslope winds behind mountains with fiords causes the reverse tip jet.
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