Open Cell Convection in the Davis Straits and Labrador Sea

Sweep of cold polar air pull down Davis Straits into the Labrador Sea by major complex depression in NE Atlantic on 28 Mar 16 forms regular pattern of open cell convection.  Convection patterns only became apparent with the advent of satellite meteorology, now they reach our desk tops every day.

This is cold air over relatively warmer sea surface.  Convection and condensation results but there is a weight of cold air above which is subsiding over a big area and the convection mixes in with this to limit vertical extent. Air descends in the open cells of the pattern.

A search for radiosonde data in this region to check the atmospheric structure is difficult.  I came up with a model ascent from Aasiaat (west coast of Greenland just to the NE of this picture).  Which does show some subsidence at about 7,000ft and is consistent with the thoughts for open cell convection.

GFS Sounding Aasiaat 28 Mar 12

Storm Katie mixes up the Atlantic air


The meteorological event of the day, storm Katie, gives a dramatic signature on all the various meteorological graphics.  MODIS channel 22 at 280230, Earthnullschool surface winds and UKMO surface analysis 280000 presented above.

Surface wind flow from Earthnullschool shows the intense wind field over SE UK, squeezed ahead of the vortex, but the NW’ly surge of air from Denmark Straits is perhaps the most striking element of this graphic.

The storm is a snag in a larger complex depression which mixes cold air from the pole to the West and warm air up to the East.  By this method, the atmosphere does its job of breaking down the temperature gradient from equator to pole and illustrates one of the keys to meteorology.