'Maritime Tropical' air by Philip Eden For the first time this
summer the UK has experienced a spell of what meteorologists
called maritime tropical air - maritime because it travels to us
via a long route across the Atlantic Ocean, and tropical because
it originates in sub-tropical latitudes. (Air from within the
tropics rarely if ever affects the British Isles.) True, there
were brief hot spells earlier in the summer, on May 15-17, June
1-2, June 16-17, and July 14-15 when the temperature has reached
the high-20s C but on these occasions the heat was associated
with air of continental origin, or at least the maritime air was
dried out by a lengthy land-track across Spain and France before
it reached the UK. One of the features of tropical maritime air-
masses at all times of the year is that they generally arrive
here with so much moisture in their lowest layers that the sky
is clogged with clouds. The clouds are usually grey and
featureless, or arranged in large soft rolls or patches, but
they are not norma