Atmosphere Flashcards
(7 cards)
Describe what happens to the solar energy that enters the earth-atmosphere system
6% is reflected by atmospheric gases and dust, 20% is reflected by clouds, 18% is absorbed by the atmosphere (3% is absorbed by clouds, 15% is absorbed by water vapour, other gases and dust), 6% is reflected by surface (varies due to albedo) and 50% is absorbed by the surface.
Why do Tropical Latitudes receive more of the Sun’s energy than Polar regions?
Curvature - oblique angle
Albedo - snow reflects
Atmosphere - thicker layer
Tilt - periods of time w no energy
Describe the main characteristics of the tropical continental air mass
It is very hot due to intense heat from Sun. It is dry with low humidity - there is no rainfall. The air is stable due to High Pressure (Sub-Tropical High Pressure Belt). Often poor visibility due to sandstorms. Weather is monotonous (always hot and dry!) Air moves Southwards as the NE Trade Winds or Harmattan
Describe the main characteristics of a tropical maritime air mass
It is hot or very hot due to intense heat from Sun. It is moist (High rainfall amounts made of both showers and intense thunderstorms) Relatively high humidity – The air does not have to rise very high for it to cool, condense and form clouds. The air is unstable meaning it will expand and rise, leading to the development of convective clouds and rain. Air moves Northwards as the SE Trade Winds
How does the ITCZ form
When the tropical maritime and tropical continental meet, moist air is forced upwards causing water vapour to condense as the air cools. This causes a heavy band of precipitation around the globe.
Describe the characteristics of the ITCZ
Low atmospheric pressure, high rainfall and occasional storms, south africa in January time, moves north by July.
Name the cells and their winds
Hadley - NE/SE Trade winds
Ferrel - Prevailling Westerlies
Polar - Polar Easterlies
