Page 145 - Thai Heritage from Space_ebook

ลมและกระแสน�้าในมหาสมุทร

C

limate

Thailand is located near the Equator.
The northern part of the country covers a vast area
of the continent where the climate is hot
and humid: Savannah climate (Aw). The southern part
includes a narrow peninsula flanked by
The Indian Ocean. The climate is that of the
tropical monsoon (Am). The average temperature
of the country is between 19 to 38 degrees Celsius,
and the highest temperatures are in mid-April.
After that, under the influence of the southwest
and northeast monsoons, it turns to the rainy season
and then winter. The overall amount of rainfall is about
1,100-1,500 millimeters per year. The heaviest rain is
found in the southern region and on the coastal areas
of the eastern region where the amount of rainfall
reaches 4,000 millimeters per year. There is a little rain
in the mountain ranges of the central region where
the amount of rainfall is less than 1,000 millimeters
per year. The duration of the rainy season
and the amount of rainfall differ according to the regions
and the altitude of the areas.
The winds and currents on the coasts of
both oceans during the two monsoon periods enable
navigation between the eastern and western regions.
One of these is the southwest monsoon which
occurs between mid-May and mid-October
and originates in the Indian Ocean.

ภาพแสดงทิศทางลมและกระแสน�้ารายเดือนบริเวณสองฝั่งมหาสมุทร จัดท�าตามรายละเอียดของ Dale, 1956 It is a southwesterly wind which assists navigation
(ทิวา ศุภจรรยา, ๒๕๕๐) from the Indian Ocean to Southeast Asia
or from the Malay Peninsula to the South China Sea.
The other is the northeast monsoon occurring
between mid-October and February. It originates
from high pressure areas in northern hemisphere,
particularly Mongolia and China. It is a northeasterly
wind, which helps in sailing southwards,
from the South China Sea to the Malay Peninsula
and sailing across to the Indian Ocean coast.

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