Numerical studies of atmospheric Kelvin waves on the west coast of Greenland

Atmospheric Kelvin waves have been tracked and studied in the marine boundary layer of coastal regions of South Africa, the west coast of North America, and Australia. One characteristic of these regions that is crucial for the propagation of these waves is that the height of the boundary layer is below that of the coastal topography, which becomes the wall against which the Kelvin wave is trapped. With its very high topography, the west coast of Greenland is a good candidate for the development of atmospheric Kelvin waves. In particular, an atmospheric Kelvin wave would propagate northwards along this coast. This sense of propagation is actually retrograde to the prevailing winds in the region, which are directed southwards along the coast. As a result, a northward traveling mesoscale low pressure region could be the signature of a Kelvin wave. In this talk we will present one such example of a weather system. On December 28, 1997 a synoptic-scale low collided with the southern tip of Greenland, and subsequently was spilt into two separate lows. The remains of the synoptic-scale system on the west side of the island spawned a polar low in the Davis Strait and excited a disturbance that propagated northwards along the west coast of the island. Both station data and high-resolution numerical simulations with MM5 show the propagation of the wave along the coast in the pressure, temperature, and wind fields.