Geoscience Reference
In-Depth Information
Fig. 4.4 Lamb's reconstruction of the July circulation pattern during the maximum Pleistocene
glaciation in the Northern Hemisphere (Lamb
1966
)
A comparison of the Harmer and Lamb reconstructions of winter and summer
circulation patterns during the maximum Pleistocene glaciation in the Northern
Hemisphere brings to light notable points of interest in the two independent
attempts to reconstruct past pressure patterns. It was regrettable for the develop-
ment of climatic research during the 20th century that there had been a hiatus of 60
years between these two studies.
Harmer's analysis of his winter chart shows a large blocking anticyclone over
Scandinavia which extended west across Greenland and southwest over the British
Isles, resulting in an east to northeasterly wind flow over the latter region; another
large anticyclone is situated over Asia. The track of the travelling depressions over
the Atlantic divides into two branches mid ocean with one branch proceeding
northeast into central Europe and the other east over the Mediterranean. This flow
reflects today's finding that a general displacement of the zonal circulation towards
