Тематический сборник текстов для чтения (английский язык). Соснина Е.П - 99 стр.

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the day, the roles are reversed. The land, cooled from a night of radiation, continues to soak
up heat long after the heat capacity of the water has been reached. Warm air over the water
rises, pulling cool air from inland to replace it. And so it goes.
Mountain breezes and valley breezes are due to a combination of differential heating
and geometry. When the sun rises, it is the tops of the mountain peaks which receive first
light, and as the day progresses, the mountain slopes take on a greater heat load than the
valleys. This results in a temperature inequity between the two, and as warm air rises off the
slopes, cool air moves up out of the valleys to replace it. This upslope wind is called a valley
breeze. The opposite effect takes place in the afternoon, as the valley radiates heat. The
peaks , long s ince cooled, trans port air into the valley in a process that is partly gravitational
and partly convective and is called a mountain breeze.
Mountain breezes are one example of what is known more generally as a Katabatic
wind. These are winds driven by cold air flowing down a slope, and occur on the largest
scale in Greenland and Antarctica. Most often, this term refers to winds which form when
air which has cooled over a high, cold plateau is set in motion and descends under the
influence of gravity. Winds of this type are common in regions of Mongolia and in glaciated
locations .
Because katabatic refers specifically to the vertical motion of the wind, this group also
includes winds which form on the lee side of mountains, and heat as a consequence of
compression. Such winds may undergo a temperature increase of 20°C or more, and many
of the world's "named" winds (see list below) belong to this group. Among the most well-
known of these winds are the chinook of Western Canada and the American Northwest, the
Swiss foehn, California's infamous Santa Ana wind, and the Spanish mistral.
The opposite of a katabatic wind is an anabatic wind, or an upward-moving wind. The
above-described valley breeze is an anabatic wind.
A widely-used term, though one not formally recognised by meteorologists, is
orographic wind. This refers to air which undergoes orographic lifting. Most often, this is in
the context of winds such as the chinook or the foehn, which undergo lifting by mountain
ranges before descending and warming on the lee side.

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