# Higher Atmosphere Earth’s Heat Budget Global Insolation

## Presentation on theme: "Higher Atmosphere Earth’s Heat Budget Global Insolation"— Presentation transcript:

Higher Atmosphere Earth’s Heat Budget Global Insolation
Global Transfer Of Energy Global Temperatures Inter Tropical Convergence Zone Climate Graph

100% Short Wave Solar Energy (Insolation)
Limit Of Atmosphere 100% Short Wave Solar Energy (Insolation) 26% Reflected (Albedo) By Clouds 18% Absorbed By Atmosphere 6% Reflected (Albedo) By Earths Surface (Long Wave) 50% Absorbed By Earths Surface

100% Short Wave Solar Energy (Insolation) Limit Of Atmosphere
26% Reflected (Albedo) By Clouds 18% Absorbed By Atmosphere 6% Reflected (Albedo) By Earths Surface (Long Wave) 50% Absorbed By Earths Surface

SOLAR INSOLATION IN EARTHS HEAT BUDGET
100% solar insolation reflected by atmosphere 26% TOTAL ALBEDO = = 32% 18% absorbed by atmosphere 56% reaches surface TOTAL ABSORPTION = = 68% reflected by surface 6% absorbed by surface 50%

The Heat Budget Only 50% of the incoming solar radiation (insolation) which reaches the atmosphere from the sun, actually penetrates to the surface of the earth. Energy which is lost is done so in 2 ways through reflection and through absorption.

This is incoming solar energy (heat). Earth’s Heat Budget Insolation Albedo Long Wave Radiation This is energy or heat emitted from the earth, only 6% escapes the earth the rest being absorbed into the atmosphere. This is the total amount of energy reflected from the earth. This is the balance between incoming and outcoming energy.

The Earth’s Heat Budget
To help you, use the following structure. Say where the earths energy come from and name it. Briefly explain what the earth’s heat budget is. Describe what happens to the insolation giving values; Atmospheric absorption (clouds) Atmospheric reflection (albedo + clouds) Surface absorption (land) Surface reflection (albedo + ice/water)

The earths energy comes from solar radiation, this incoming heat energy is balanced by the amount of heat escaping back into space. This balance is called the earths heat budget. Incoming solar heat (insolation) from the sun is absorbed and reflected meaning not all the heat reaches the earths surface. 26% of the energy is reflected back into space by the earths atmosphere and 18% of the heat is absorbed by the atmosphere due to dust particles retaining the heat. This leaves 56% which travels to the earths surface. Not all of this is absorbed 6% is reflected from the earths surface by polar ice caps & water, and this makes up part of the earths Albedo. This means only 50% reaches the earths surface and is balanced out by the long wave radiation escaping back into the atmosphere.

Variations in Global Temperatures
To understand the reasons as to why the poles are in deficit and the equatorial regions have an energy surplus

Global Insolation The Earth's atmosphere is put into motion because of the differential heating of the Earth’s surface by solar insolation. This means that the winds and clouds above us move around because there are some areas of the earth which are hotter than others. We therefore need to know why these difference occur, so we can then study the different movements of the weather in the atmosphere. This then lets us make accurate weather forecasts.

Variations in Insolation
The amount of insolation at the Earth’s surface varies according to latitude – most heat is received at the Tropics and least heat is received at the Poles. As a result, there is a net gain of solar energy in the tropical latitudes and a net loss towards the poles.

Reasons for Variations in Insolation
Surface area to be covered is greater at Poles than Tropics so more insolation lost at Poles. More atmosphere to pass through at Poles than Tropics so more insolation lost at Poles. Position of sun – the sun is high in sky all year round at Topics whereas at Poles there is no insolation for 6 months of the year. Albedo. Snow and ice covered Poles reflect insolation. Forested Tropics absorb it.

Differing Depths Of Atmosphere
Global Insolation Task 4 (1) Differing Depths Of Atmosphere Different Curvature Differing Albedos High Albedo Low Albedo Insolation Energy From The Sun

Different Curvature High Albedo Insolation Low Albedo Differing Depths Of Atmosphere

Task 5 Latitude & Distribution Of Solar Energy
Distance: Insolation from the sun travels different distances, and hence amounts of air, because of the curvature of the earth. At the equator there is a shorter distance to travel, but at the poles there is a greater distance to reach the land. This means that the insolation will be weakened more approaching the poles than at the equator and so make it cooler at the poles. Curvature: The curvature of the earth also has an effect on the distribution of solar energy. The sun’s rays are more concentrated at the equator so it is hotter or has more solar energy. At the poles the same rays are spread over a greater distance so there heat is spread making it cooler. The poles therefore have less solar energy than the equatorial regions. Albedo: The high quantities of ice at the poles mean there is a high albedo (reflection), so that insolation is reflected and the poles receive less solar heat/radiation. The equatorial regions have high concentrations of rainforest, the dark green colour absorbing insolation and so receive more heat.

Variations In Global Insolation
Describe With the aid of an annotated diagram describe and explain the energy balance shown on the diagram below. Range of latitude 35° to 0° (N or S of) Equ. State if in deficit or surplus Give values in Joules 170 to 270 Range of latitude 35° to 90°N or S of Equ. State if in deficit or surplus Give values in Joules 50 to 170

Variations In Global Insolation
Explain In Detail Why deficit in high latitudes (polar areas) and why surplus in low latitudes (equatorial areas) Insolation - distance travelled through atmosphere greater at poles so heat lost Concentration of insolation higher at equator due to curvature of earth Albedo high at poles and low at equator

Global Transfer Of Energy
This is the movement of energy from the equator to the poles. Global Insolation differences should mean that the lower latitudes (equator) get hotter and hotter, whilst the higher latitudes (poles) get colder and colder. In reality this doesn’t quite happen as energy is transferred from surplus areas (equator) to deficit areas (poles) by two methods. Atmospheric Circulation & Ocean Currents

The air warms again and so rises giving rain Atmospheric Circulation (Task 7) The cool air then starts to fall back to the earth Finally the cool air sinks at the poles having distributed heat from the equator to the poles Hot air at the equator rises This cools as it rises giving cloud and then rain

Colour in the cells A, B & C.
30N° 60N° 90N° A B C A = Hadley Cell B = Ferrel Cell Colour in the cells A, B & C. C = Polar Cell

Atmospheric Circulation Cells
The three weather cells. The Hadley Cell ~ this circulates air between the equator 0° and the tropics of, Capricorn in the south (30°S) & Cancer in the north (30°N). The Polar Cell ~ this circulates air between the North Pole & the Arctic circle (90°N & 60°N) The Ferrel Cell ~ this isn’t actually a cell but circulates air through friction between the tropic of Cancer & Arctic Circle in the North (30°N & 60°N) and the Tropic of Capricorn & Antarctic Circle in the south (30°S & 60°N)

Equatorial Low Pressure Sub Tropical High Pressure Sub Tropical High Pressure

Atmospheric Circulation Polar Cell
Cool air falls at the poles. Polar High Pressure As the air rises it starts to cool. 90°N °N The warm air rises at 60°N. Temperate Low Pressure. The air spreads south, warmed by the sea and land.

Atmospheric Circulation Ferrel Cell
Polar Cell Hadley Cell Hadley Cell Ferrel Cell 90N° N° N° ° S° Rising warm air from Polar Cell pulls up air with it. Descending cool air from Hadley Cell drags down more air with it Air dragged by both Cells causes air to circulate, Ferrel Cell, and distribute heat from the equator to the poles.

Atmospheric Circulation Winds
The next slide shows how winds move across the surface of the earth. A Key Principle is that these winds move from areas of high pressure to low pressure. Complete the diagram showing surface winds in your workbook.

90N° PC 60N° FC 30N° HC 30S° 60S° 90S°

30N° 60N° 90N° 60S° 30S° 90S° Air falling at the Polar High Pressure (90°N) move towards the Temperate Low Pressure (60°N) called Polar Easterlies. Falling air at the Sub Tropical High Pressure (30°N) moves towards the Temperate Low Pressure (60°S) called Westerlies. Falling air at the Sub Tropical High Pressure (30°N) also moves towards the Equatorial Low Pressure (0°) called the North East Trade Winds. The last winds we really need to know are called the South East Trade winds which result from falling air (high pressure) at 30°S. Where air rises at the Equatorial Low Pressure there are light wind called the Doldrums.

Ocean Currents - Global Transfer Of Energy
Ocean currents like Cells and wind redistribute energy. Heat is taken from the tropics and moved towards the pole & vice versa. For the exam you will have to describe the movement of these currents and be able to explain why they move in the way that they do.

Description of Ocean Currents
Help redistribute energy from areas of surplus to deficit. Account for 20% of energy redistribution. Warm currents flow from Equator to Poles. Cold currents flow from Poles to Equator. Warm currents – Gulf Stream, North Atlantic Drift. Cold currents – Canary, Labrador Move in large circular loops called gyres. Clockwise in the Northern Hemisphere. Anticlockwise in the Southern Hemisphere.

Factors influencing the flow of Ocean Currents
Winds – currents follow prevailing winds. Land Masses – block and deflect currents and send them off in other directions. Corioilis Force - deflects currents to the right in the northern hemisphere and the left in the southern hemisphere. Salinity(salt) differences in water – flow from low to high salinity – equator – sub-tropics. Uneven heating of water – cold polar water sinks, flows towards equator and displaces upwards the warmer water setting up gyres.

Colour this line red, it is the warm Gulf Stream
Colour this line in blue, it is the cold Labrador current. Colour this line blue, it is the cold Canaries Current Colour this line red it is the warm Equatorial Current

Ocean Currents Description
The currents of the oceans circulate in large loops called gyres. These currents form in warm equatorial areas and cold polar areas. In the North the currents flow in a clockwise direction. In the South the currents flow in an anticlockwise direction.

Ocean Currents Description
In the North Atlantic Gyre a warm current from the equator heads towards the Caribbean, the North Equatorial Current. It then moves in a North Easterly direction towards Europe, as the Gulf Stream Current. A cold current from Northern Canada, called the Labrador current joins the Gulf Stream cooling it down. The current starts to flow south down the African coast to the equator, the Canaries Current, but by now is much cooler. The cycle then starts to repeat itself.

Ocean Currents Description
The distribution of heat can actually be seen in a figure of 8 pattern as the two gyres in the Atlantic meet at the equator. Remember in these questions you must mention that the warm water spreads heat pole wards and the cool water helps cool the equatorial regions. The current then turns Easterly towards South Africa and flows up its Western coast, the Benguela Current. The current starts to warm up again as it moves up the African coast where it rejoins the warm South Equatorial Current. Some of the warm current from the equator, South Equatorial Current, starts to flow South West to the Brazilian coast, Brazilian Current, cooling as it travels South.

Ocean Currents Explanation
When explaining how these currents circulate there are 4 key points to make as well as one explaining temperature chnages; Wind Coriolis effect Position Of Continents Convection Currents You also need to know why the currents warm or cool For Task 14 you will split into groups to find out about these key points, reporting back to each other what you find.

Ocean Currents Explanation
Prevailing Winds The Trade winds and the Westerlies drive the ocean currents in a clockwise direction a result of falling & rotating air at the sub tropics (30ºN). The equatorial current is picked up by the North East trade winds & sent to the caribbean, the rotation then continues so that the Westerlies send the current to the North East. North East Trade Winds Westerlies

Ocean Currents Explanation
Coriolis Effect This is the West to East rotation of the earth that drives the ocean currents the northern hemisphere in a clockwise direction

The continents deflect currents into a clockwise movement
Ocean Currents Explanation North America Europe The continents deflect currents into a clockwise movement Africa

Ocean Currents Explanation
More insolation received at the equator than the poles results in convection currents. Warm currents rise at the equator and then drop back down into the sea at higher latitudes, helping to mix warm and cold currents.

Ocean Currents Explanation
Explaining distribution of cold and warm temperature by currents. You also have to state the obvious! As warm currents move northwards from the equator, they distribute heat to the cooler high latitudes nearer the poles. At the same time, movement of cold currents from the poles to lower latitudes helps to distribute cool temperatures to the warm equatorial areas.

Changes In Global Temperatures
Diagram Showing Global Temperature Variations -0.8 This Trend Fluctuates Upwards -0.6 +0.4 Global Mean Temperatures Have Risen +0.2 Average Global Temperature 0°C -0.2 -0.4 -0.6 1975 2000 1850 1875 1900 1925 1950

Changes In Global Temperatures
Diagram Showing Global Temperature Variations Lowest value -0.42°C Highest Value 0.4°C Temperature Range 0.82 °C +0.8 +0.6 +0.4 +0.2 Average Global Temperature 0°C -0.2 -0.4 -0.6 1975 2000 1850 1875 1900 1925 1950

Changes In Global Temperatures
Diagram Showing Global Temperature Variations -0.8 -0.6 +0.4 Rapidly Increasing Temperature Above Average +0.2 Average Global Temperature 0°C -0.2 to -0.1°C below Average Temperature -0.2 -0.4 to – 0.3°C Below Average Temperature -0.4 -0.6 1975 2000 1850 1875 1900 1925 1950

Changes In Global Temperatures
The overall trend is that the Global mean temperature has fallen/stabilised/risen between 1850 & 2000, in a steady/fluctuating manner against the 1951–1990 average/long term average. The lowest value was -0.42/-0.38 °C and the highest +0.4 °C giving a range of -0.2/+0.2/0.78/0.82 °C around the mean for There was a period with below average temperatures of around -0.4°C to °C between 1850 & 1920/1850 & 1950/1940 & There was a period of gentle increase between -0.2°C & -0.1°C below the 1950 average from 1920 & 1940/1920 & A period of slow/moderate/rapid increase above the 1950 mean took place between 1940 & 2000/1975 & 2000.

Changes In Global Temperatures
Physical Factors Dust from volcanoes reflects away insolation Sunspot activity sends more insolation to the earth

Changes In Global Temperatures
Physical Factors If the earth’s orbit changes we can be further from the sun and start to cool.

Changes In Global Temperatures
Physical Factors If the earth tilts away from the sun the Northern Hemisphere will cool

Changes In Global Temperatures
Human Factors CO2 absorbs heat and reradiates heating up the earth. Deforestation adds CO2 when trees burnt and less CO2 converted into water by trees. Methane, Nitrous Oxides & CFC emissions do the same as CO2.

Inter Tropical Convergence Zone (ITCZ)
This is simply the area between the two Tropics (Cancer & Capricorn) where two different air masses meet. As it is a low pressure area/belt there is rain. This is a result of the high levels of insolation at the equator causing the movement of warm air upwards. First try and work out a few definitions for Task 16, use your knowledge of the English language & your teacher to help.

Inter Tropical Convergence Zone (ITCZ)
between the tropics of Cancer & Capricorn. Inter Tropical Convergence Zone where two or more things meets in this case air masses ? ITCZ an area Task 16

ITCZ The migration of the inter-tropical convergence zone (ITCZ) in Africa affects seasonal rainfall patterns across the continent. It is an area of low pressure that forms where the Trade Winds meet near the earth's equator. As these winds converge, moist air is forced upward. As it rises, the air cools, resulting in a band of heavy rain around the globe. This band moves seasonally, due to the changing position of the overhead sun.

Position of the ITCZ: January
Tropic of Cancer Equator Tropic of Capricorn

Task 17 ITCZ Air Masses Air masses = ? Tropical climate = ? & why
Maritime climate = ? & why Tropical Continental (cT) Dry Continental climate = ? & why When describing air masses you must say; Where they develop Where they move to How stable they are Their temperature & moisture characteristics What the weather will be like Tropical Maritime (mT) Wet

Task 18 ITCZ January Rain as sun & ITCZ located over Tropic of Capricorn Tropical Continental Dry Dry area north of ITCZ as Continental air is dry and stable, from Sahara Desert ITCZ Tropical Maritime Wet

Task 18 ITCZ March Rain around equator as ITCZ located by it
Tropical Continental Dry Wet area south of ITCZ as Maritime air is wet and unstable Dry area north of ITCZ as Continental air is dry and stable Tropical Maritime Wet

Task 18 ITCZ July Rain as sun and ITCZ located over Tropic of Cancer
Tropical Continental Dry ITCZ Wet area just south of ITCZ as Maritime air is wet and unstable Some convectional rainfall between 5º N & S of the equator. Tropical Maritime Wet

Task 18 ITCZ September Rain around equator as ITCZ located by it
Tropical Continental Dry Wet area south of ITCZ as Maritime air is wet and unstable Dry area north of ITCZ as Continental air is dry and stable Tropical Maritime Wet

January Equator Tropic of Capricorn Tropic of Cancer I T Z C

March Tropic of Cancer I C T Z Equator Tropic of Capricorn

July Tropic of Cancer I C T Z Equator Tropic of Capricorn

September Equator Tropic of Capricorn Tropic of Cancer I C T Z

January Tropic of Cancer I T Z C Equator Tropic of Capricorn

March Tropic of Cancer I C T Z Equator Tropic of Capricorn

July Tropic of Cancer I C T Z Equator Tropic of Capricorn

September Tropic of Cancer I C T Z Equator Tropic of Capricorn

January Tropic of Cancer I T Z C Equator Tropic of Capricorn