Tropical Rain Forest Climate(Af)



The tropical rain forest supports one of the most lush and diverse environments
on Earth.
Its location near the equator dominates all aspects of the climate.
Year-round warm temperatures and copious rainfall characterize the rain forest
climate.
Rain forest of UGANDA
Geographical Distribution





The rain forest climate is generally found straddling the equator and along
tropical coasts that are backed by mountains and exposed to the trade winds.
The climate tends to be restricted to low elevations (below 1000 meters)
Large regions of rain forest climate are found in the Amazon River basin of
South America,
the Congo River basin of Africa,
the east coast of Central America and
Madagascar. Malaysia, Indonesia, and the Philippines .
http://www.youtube.com/watch?v=_F1hBgOz8nA&feature=related





Distinguishing Characteristics
The equatorial location of the tropical rain forest places it in a region of high
annual insolation. High sun angles throughout the year make for high annual
temperatures with very little seasonal variation. The temperature in a rain
forest rarely gets higher than 93 °F (34 °C) or drops below 68 °F (20 °C)
Located in the heart of the Intertropical Convergence Zone and near mE and
mT source regions,
high annual precipitation is experienced in all months. An average of 50 to 260
inches (125 to 660 cm.) of rain falls yearly. ); average humidity is between 77
and 88%
Temperature
Constant high temperatures throughout the year.
In addition, the direct rays of the sun pass over the climate twice throughout the year
creating two periods of maximum insolation.
Given that the circle of illumination bisects the equator, day length tends to be nearly
the same day-after-day.
Annual temperatures in the rain forest average between 20o - 30o C (68o - 86o F).
Annual temperature range rarely exceeds 3o to 4o F.
In fact, the daily range of temperature is often larger (10o - 12o F) than the annual
range in temperature.
The larger daily ranges are due to the
sunny mornings and cloudy afternoons
of cooling rain.
Precipitation
The rain forest is noted for its copious
rainfall occurring in all months of the year.
Over 200 cm (80 in) of precipitation
annually falls in the rain forest.
Abundant precipitation occurs in each month
and is fairly evenly distributed between high
and low sun seasons.
largely generated by convective uplift of warm, moist equatorial air (mE).
A distinctive diurnal pattern of cumulus cloud development in the morning,
precipitation in the early afternoon, followed by dissipating clouds towards the late
afternoon is typical. Thunderstorms are usually concentrated in small areas, so their
duration is short but intense.
Convective Rain Brazil














Humidity in the rain forest can be oppressive
Since humidity is so high during the day, when cooling occurs at night, early
morning radiation fogs form and heavy dew drips from the rain forest vegetation.
These condensation products evaporate into the air as the Sun rises, thus
increasing the air's humidity.
The rainforests are home to two-thirds of all living animal and plant species
on earth.
Hundred of millions of plants, insects and micro organism remains undiscovered.
Rainforests now cover less than 6% of Earth's land surface.
Scientists estimate that more than half of all the world's plant and animal
species live in tropical rain forests.
Tropical rainforests produce 40% of Earth's oxygen.
About 1/4 of all the medicines we use come from rainforest plants.
Curare comes from a tropical vine, and is used as an anesthetic and to relax
muscles during surgery.
Quinine, from the cinchona tree, is used to treat malaria.
A person with lymphocytic leukemia has a 99% chance that the disease will go
into remission because of the rosy periwinkle.
More than 1,400 varieties of tropical plants are thought to be potential cures for
cancer.
http://www.youtube.com/watch?v=rOZB39QHjro&feature=related
Tropical Monsoon Climate (Am)
The tropical monsoon climate experiences abundant rainfall like that of the tropical rain
forest climate, but it is concentrated in the high-sun season.
Being located near the equator, the tropical monsoon climate experiences warm
temperatures throughout the year.
Geographical Distribution
The monsoon climate is found along the coastal regions of southwest India, Sri Lanka,
Bangladesh, Myanmar, Southwestern Africa, French Guiana, and northeast and
southeastern Brazil.: Controlling Factors
Figure AC.17 Monsoon Circulation Summer
Winter
The major controlling factor over the monsoon climate is its relationship to the monsoon
circulation. Recall that the monsoon is a seasonal change in wind direction.
The "classic" monsoon circulation of Asia exhibits an onshore flow of air (air moving
from ocean towards land) during the summer or high-sun season, and
offshore air flow (air moving from land toward water) during the winter or low-sun
season. The change in direction is due to the difference in the way water and land heat.
Changing pressure patterns that affect the seasonality of precipitation also occur in
Africa. During the high-sun season, the ITCZ induces rain while the subtropical
high creates dry conditions. The monsoon climate of Africa, and South America
for that matter, are typically located along tradewind coasts.
Figure CS.4 Climograph for
Mangalore, India
Lat/Long = 12.53o N, 74.52o E
Average Annual Temperature (oC) =
27.05
Annual Temperature Range (oC) = 3.6
Total Annual Precipitation (mm) =
3409.2
Summer Precipitation (mm) = 3115.9
Winter Precipitation (mm) = 293.3
Distinguishing Characteristics
Temperature
Temperatures remain high all year in the monsoon climate.
The average annual temperature is 27.05 oC (80.7oF) but only has an annual
temperature range of 3.6 oC (2oF). The monsoon climate's temperature range is
somewhat similar to that of the rain forest, but it exhibits a slightly different temporal
pattern.
The monsoon climate tends to have its highest temperature just before rainy period.
Once the rainy period starts, clouds block incoming solar radiation to reduce monthly
temperatures.
Figure CS.5 Comparison of monthly temperature in the
rain forest (Iquitos) and monsoon climates (Mangalore).
Precipitation
Seasonality of its precipitation is the hallmark and most well-known characteristic
of the monsoon climate.
Though the annual amount of precipitation is quite similar to that of the rain forest,
monsoon precipitation is concentrated into the high-sun season.
Maritime equatorial and maritime tropical air masses travel from the ocean on to land
during the summer, where they are uplifted by either convection or convergence of air
to induce condensation.
Locally, orographic uplift is an important mechanism for promoting precipitation.
As air travels into the Indian subcontinent, it is uplifted by the Himalayas, causing
cloud development and precipitation.
Air masses that dominate this period are dry given their continental origin (cT, cP) or
stability (mTs).
http://www.youtube.com/watch?v=JdKTMqtP7dM
Tropical Wet/Dry (Savanna) Climate (Koeppen's Aw),
Figure CS.6 Impala on the Savanna.
(Source: FAO)
The Tropical Wet/Dry climate is located on the
poleward sides of the tropical wet climates, positioned
between them and the tropical dry climates. This
location places the climate at an intermediate position
between the ITCZ and the Subtropical High. As a
result, the climate experiences a distinct seasonality
to its precipitation like that of the tropical monsoon climate. Also known as the
"Savanna" climate, it supports a ground cover of drought resistant grasses with
scattered trees, but not enough rainfall to make agriculture a viable, life sustaining
activity.
Geographical Location







The Tropical Wet/Dry climate lies at latitudes of about 5o - 10o and 15o - 20o.
Broad expanses of the savanna exist in north and south central Africa,
The Llanos of Venezuela,
Campos of Brazil,
much of northern and eastern India,
western Central Australia
Myanmar (Burma) and the Indo-Chinese Peninsula
Figure CS.7 Climograph for Dakar, Senegal
Click image to enlarge
Controlling Factors
Its position at about 15o North or South latitude
places the Tropical Wet/Dry climate in a zone
between the alternating influence of the
Intertropical Convergence Zone (wet season) and
the (dry season) subtropical high.
Climate. A tropical wet and dry climate predominates in areas covered by savanna
growth.




Mean monthly temperatures are at or above 18oC (64.4oF) to above 25oC (77oF
Annual precipitation averages between 30 and 50 inches. For at least five
months of the year,
During the dry season, less than 4 inches a month are received.
The dry season is associated with the low sun period.
Soils. laterization is the dominant soil-forming process and low fertility
Regional expressions.






East African savannas are typically, perhaps stereotypically, acacia savannas.
Many survive in the famous game parks of Kenya and Tanzania, and also those
of Zimbabwe, Botswana, South Africa, and Namibia.
 The savannas are actually a mosaic of communities controlled (and today
managed) by fire and grazing pressures.
 The famous Serengeti Plains in Tanzania are a grass savanna developed on
droughty but nutrient-rich volcanic sands.
The llanos of the Orinoco basin of Venezuela and Colombia are grass savannas
maintained by the annual flooding of the Orinoco and Arauca rivers and their
tributaries.
The long periods of standing water inhibit the growth of most trees.
Brazil's cerrado is an open woodland of short-stature, twisted trees. It is speciesrich, second only to the tropical rainforest in plant diversity. Shield of South
America.
The pine savannas of Belize and Honduras, in Central America, occur on
sandy soils.
Fauna.

The world's greatest diversity (over 40 different species of hoofed mammals is found
on the savannas of Africa.

The antelopes are especially diverse and including eland, impalas, gazelles
oryx, gerenuk, and kudu. Buffalo, wildebeest, plains zebra, rhinos, giraffes,
elephants, and warthogs are among other herbivores of the African savanna.
Up to sixteen grazing and browsing species may coexist in the same area.
They divide the resources spatially and temporally; each having its own food
preferences, grazing/browsing height, time of day or year to use a given area,
and different dry season refugia.


Supports a diverse set of carnivores, including cats (lions, leopards,
cheetahs, servals), dogs (jackals, wild dogs), and hyenas.

Most herbivorous mammals of the open savannas are herd animals, often
organized into groups of females and their young with a single dominant
male and groups of bachelor males.
Termites are especially abundant in the tropical savannas of the world, and their tall
termitarias are conspicuous elements of the savanna landscape. T
http://www.youtube.com/watch?v=AJracGoRUTs