"At first, the strato-cumulus has bases approximately 1,500 to 

 2,500 feet and tops at the base of the inversion, the height of which 

 varies with the distance of travel from the continent. With aver- 

 age pack composition and a travel of 150 miles across it, these tops 

 will be 3,000 to 4,000 feet high. From these average figures the 

 approximate stage of development from cAK to mAK can be es- 

 timated by considering that longer travel and more open water 

 increases the height of the tops and lowers the bases, while shorter 

 travel and less open water decreases the height of the tops and 

 raises the bases until finally no clouds result in the extreme case. 

 Snow showers develop higher than 6,000 feet. Convergence and 

 divergence affects respectively augment or limit the above trans- 

 formation of cAK to mAK. 



"After the strato-cumulus clouds have been well developed, that 

 is, with a total water travel of at least 50 miles, the air is consid- 

 ered to be mA. This mA air exists primarily in wedges extending 

 northward from the Antarctic Anticyclone, in bubble highs devel- 

 oping from these wedges, and in flow paralleling the continent 

 north of the pack over the sea. The mAK air exists in the eastern 

 and northern sectors of the wedges and bubble highs where the 

 flow tends northward. This air then turns southward becoming 

 mAW in the western and southern sectors. It is characterized by 

 a stable layer from the surface to about 500 feet and a moist adia- 

 batic lapse rate above that to 1,500 to 3,000 feet, above which is 

 an inversion of one degree to four Centigrade. This inversion be- 

 comes progressively lower the farther the southward travel. 

 Above the inversion the lapse rate is very stable. Stratocumulus 

 and stratus clouds lie beneath the inversion with ragged bases 

 from 500 to 1,000 feet. In bubble highs these clouds frequently 

 totally dissipate near the southern limit of the air trajectory be- 

 cause of the lack of the vertical convection needed to maintain 

 these clouds. Patches of fog develop after a net southward travel 

 of about 100 miles and become denser the farther south the air 

 travels. The transitional area from mAK to mA to mAw occurs 

 in the north to northwest section of the wedges and bubble highs 

 as the air begins returning southward. Here snow showers cease 

 and the strato-cumulus tops lower to 2,500 to 3,500 feet with bases 

 at 1,000 to 1,500 feet. 



"The opposite transitional area from Aw to mA to mAK that 

 occurs in the south to southeast section of bubble highs is one of 

 frequent clear skies and excellent visibility. Here patchy fog is 

 dissipated due to heating from below and the strato-cumulus cloud 



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