Weather is driven by the sun and the uneven distribution of heat between the equator and the poles. In essence, weather is the atmosphere reorganizing itself to try and smooth out this temperature difference. The Earth's axis also has a tilt relative to the sun, meaning a location will receive a different amount of heat at different times of the year: some parts of the year will be warm (summer) and others will be cool (winter). This gives rise to the four seasons we are familiar with.
Since tropical regions are close to the equator, the difference in the
heat they receive over the course of the year is only small, leading to small
variations in temperature. A more noticeable change between these two times of
the year is the amount of rain that falls with a distinct wet and dry season.
So it's more appropriate to describe the season in the tropics by rainfall
amount than the temperature.
The largest areas of Tropical
Wet/Dry are found in Africa, Brazil, and India. The tropics are two lines of
latitude about 23.5 degrees north and 23.5 degrees south of the Equator. Land
in this area receives direct sunlight throughout most of the year.
Tropical Wet and Dry is known for its two seasons: wet season and dry
season.
The
wet season in the tropical savanna
generally lasts from June to October in the northern hemisphere and from about
December to April in the southern hemisphere. The rain results from a
combination of warm, tropical air masses from large bodies of water and the sun
positioned higher in the sky. Temperatures remain high during the wet season
but can drop into the 50s at night. Depending on the location and the year, the
wet season can result in annual rainfall of less than 10 inches to more than 50
inches.
Organisms
in this climate depend on the cycle of wet and dry in order to survive. Without
the wet season, the vegetation in the area wouldn't be able to survive through
the dry season. But without the dry season, it would be too wet to form the
environments that have formed there and would likely result in strictly forest
environments as opposed to a variety of environments like savannas and
grasslands.
Most
dry seasons in the northern
hemisphere begin around November and last through June when the rains return.
In the southern hemisphere, dry seasons tend to last from about May through
November. Temperatures reach their highest near the end of the dry season
before the rains come. The average daily temperature in the dry season is in
the upper 70s Fahrenheit, but depending on the location daytime temperatures
can climb above 100 degrees Fahrenheit.
The
dry season has little or no rainfall due to continental tropical air masses and
the sun is lower in the sky. The higher the latitude of the region; the longer
the dry season tends to be. Many waterholes and creeks dry up completely, and
grasslands turn brown. Bushfires are common. These fires are often started by
Aboriginal people, continuing a practice going back many thousands of years to
manage the fuel load on the land (to try to prevent really big fires) and to
drive animals so they can be caught for food.
“[A] pluviophile
[is] a lover of rain. [It is] someone who finds joy and peace of mind
during rainy days.” (Anonymous)[i]
[i] Sources used:
·
“The wet and the dry:
seasons in the tropics” by Australian Government Bureau of Meteorology
·
“TROPICAL WET AND DRY CLIMATE” by Climate Types for Kids
·
“Wet and Dry Seasons”
by Questacon
·
“What Are Tropical Wet and
Dry Climates?” By Kevin Carr
This topic was suggested
by my missionary daughter, Allena, who is experiencing this in Ghana, Africa.
Your mom and I love you, and miss you.
No comments:
Post a Comment