Atmo: Climatic Zones Flashcards
Where are AF climates found?
Within 10 degrees north and south of the equator
Describe temperatures in the AF climate.
Average Monthly Temperatures: high (27degrees)
Annual Temperature Range: low (1.7degrees)
Diurnal temperature range: low
Why is average monthly temperatures in AF climates high?
Close proximity to the equator enables energy surplus throughout the year.
- less beam spreading
- less atmosphere to pass through
- low albedo
Why is annual temperature range in AF climate so low?
- presence of moisture all year round to allow insolation to be expended on evapotranspiration rather than increasing surface temps
- cloud cover reflects insolation back to space all year round
Why is diurnal temperature range in AF climates small?
Presence of cumulus clouds with high albedo to reflect insolation during the day and trap long wave radiation at night.
Describe precipitation in the AF climate.
Total annual rainfall: high at 241cm
Distribution of rainfall: uniform distribution
Why is total annual rainfall in AF climates so high? (Hint: convectional rainfall)
Close proximity to ITCZ all year round enables intense solar heating that causes a steep ELR and an unstable atmosphere. Pockets of rising air due to uneven surface heating will rise as they are warmer as less dense. This leads to adiabetic cooling and cloud formation upon reaching dew point.
Account for the uniform distribution of rainfall in AF climates.
Since the ITCZ never migrates far from the region, high rainfall occurs constantly due to lack of seasonality
What are the 4 different climatic zones?
Af, Am, Aw, Bwh
Where is Akyab, Myanmar found?
20degrees North 93degrees East
When are the wet seasons for the AM climate?
MJJAS
What are the average monthly temperatures like for AM climates?
High 25degrees for Akyab
What’s the annual temperature range for AM climates? And why? (2 reasons)
Low but higher than AF 7.8degrees for Akyab
Dip in temp during wet season as insolation is reflected by thicker cloud cover. During the warmer season, less cloud cover, allows more solar radiation to reach the surface. Also, position is further from the equator than AF, hence seasonal temp changes more distinct
What’s the diurnal temperature range for AM climates and why?
Low compared to drier climates.
Presence of cloud over most months. Insolation reflected by thick cloud cover during the day and prevents escape at night
What is the total annual rainfall for AM climates?
521cm (one of the highest in the world)
What is the distribution of rainfall in AM climates?
Strong seasonality (short dry season at the end of the year) Very high rainfall at 60cm/month in the middle of the year.
Explain the presence of the dry season in Akyab, Myanmar.
During December when the northern hemisphere experiences winter, the development of the Siberian High (colder->high pressure), tgt wth the PGF and coriolis force, at the centre of the Asian continents causes the arrival of the dry NE monsoon that brings the dry season to Akyab. (Since the wind crosses land and does not pick up much moisture)
Explain the presence of the wet season in Akyab Myanmar
During June when the northern hemisphere experiences summer, the ITCZ shifts north from the Southern Hemisphere to the Tibetian Low developing in northern India. The trade winds crosses the equator and due to the PGF and coriolis force, approaches Akyab from the South West (SW monsoon), pick up moisture from the Bay of Bengal and cause the arrival of the wet monsoon.
Give a specific location of the AW climate, include latitude and longitude
Bamako, Mali (13degrees North 8 degrees West)
What is the annual monthly temperature for the AW climate
High
What is the Annual Temperature Range for AW climates
Greater due to its location being further away from the equator
What is the diurnal temperature range for AW climates?
Greater especially during the dry season due to absence of clouds. Cloud cover decreases the amount of insolation reaching the surface and the amount leaving it. Absence of clouds facilitates greater daytime heating and nighttime cooling. During the wet season, high humidity and cloud cover reduces diurnal ranges.
Imagine the climograph of the AW climate
Wet months: MJJAS
Precipitation: peak at Aug
temperature: 20-40 range peak at May-June
What is the total annul rainfall in the AW climate
Less than AF and AM climates 113cm
What is the distribution of rainfall in AW climates? 2parts answer
Strong seasonality: long dry season of about 7months, short wet season from May to Sep
Great yearly variability
Explain the presence of the dry season in the AW climate
ITCZ is in the Southern Hemisphere and under the influence of the subtropical high to bring descending air and the resistant lack of precipitation due to little condensation occurs.
Great year to year variability: depends on how far the ITCZ shifts north as it brings rainfall
Explain the presence of the wet season in AW climates
ITCZ is in close proximity to the region in the middle year. Conventional rainfall results due to intense solar heating and an unstable atmosphere. Presence of wet season depends on proximity to ITCZ.
Name the location of the BWH climate and state the latitude
Cairo, Egypt (31degrees North 31degrees East)
What is the average monthly temperature of the BWH climate
Highest of all 4 climates
What is the annual temperature range in the BWH climate
Largest as location is furthest away
What is diurnal temperature range for the BWH climate
Very great due to the lack of cloud cover due to poleward location. Daytime temperatures can be extremely high as combination of low humidity, high sun and clear skies allows high inputs of solar radiation to be absorbed at the surface. At night, the clear skies and low humidity allow the air to cool rapidly, causing nighttime temps to drop drastically.
What is the total annual rainfall in BWH climate
2.5cm (very low)
What is the distribution of rainfall in BWH climates
Dry throughout -> infrequent storm and great variability
Explain the lack of precipitation in the BWH climate throughout the year (6 steps)
1) Subsidence of air
2) compression
3) adiabatic heating of descending air
4) increase temp and reduces RH
5) impedes condensation and cloud formation so rainfall is very low
6) warming of upper layers will cause a gentler ELR, forming a stable atmosphere
Name a coastal desert
Atacama desert
