INSOLATION, EARTH’S HEAT BALANCE, DIFFERENT ATMOSPHERIC CIRCULATIONS

INSOLATION, EARTH’S HEAT BALANCE, DIFFERENT ATMOSPHERIC CIRCULATIONS – GLOBAL WINDS, CYCLONES

Contents

1. Insolation 159

1.1. Factors Influencing Insolation 159

1.2. Heating and Cooling of the Atmosphere 161

2. Heat Budget 162

2.1. Latitudinal Heat Balance 164

3. Temperature 164

3.1. Distribution of Temperature 167

3.2. Temperature Anomaly 168

3.3. Temperature Inversion 168

3.4. Temperature Ranges 169

4. Atmospheric Circulation 170

4.1. Atmospheric Pressure 170

4.2. Pressure Variations 170

4.3. Forces Governing Air Movement 172

4.3.1. Pressure Gradient 172

4.3.2. Coriolis Force 173

4.3.3. Centripetal Force 174

4.3.4. Frictional Force 174

4.4. Geostrophic Wind 174

4.5. Distribution of Pressure Belts 174

4.6. Shifting of Belts 175

4.7. General Circulation of the Atmosphere 176

4.7.1. Planetary Winds 176

4.8. Local Winds 177

4.8.1. The Land and Sea Breezes 177

4.8.2. The Mountain and Valley Breezes 178

4.8.3. Hot Local Winds 179

4.8.4. Cold Local Winds 179

4.9. Upper Air Circulation 180

4.9.1. Jet Streams 181

5. Air Mass 183

6. Fronts 184

6.1. Warm Front 185

6.2. Cold Front 186

6.3. Stationary Front 186

6.4. Occluded Front 186

7. Cyclones 186

7.1. Extra-Tropical Cyclones 187

7.2. Tropical Cyclones 189

7.3. Thunderstorms and Tornadoes 191

7.3.1. What Causes Lightning and Thunder 192

7.3.2. Why Thunders are Cause of Concern 193

1. Insolation 1.1. Factors Influencing Insolation Figure 1 – effect of angle of inclination on Insolation Table 1 – Length of Day on winter and summer Solstices in the Northern Hemisphere Figure 2 – average annual insolation on the surface of the earth 1.2. Heating and Cooling of the Atmosphere Figure 3 – (a) processes of heating and cooling of atmosphere and (b) per cent share of processes in heating up of atmosphere 2. Heat Budget Figure 4 – Heat Budget of the Earth Figure 5 – heat energy budget by latitudes 3. Temperature (a) – effect of altitude (b) – maritime influence Figure 6 – effect of altitude & distance from sea on temperature Figure 8 – isotherms in the month of January Figure 9 – isotherms in the month of July 3.3. Temperature Inversion Figure 10 – temperature inversion 3.4. Temperature Ranges 4. Atmospheric Circulation 4.1. Atmospheric Pressure 4.2. Pressure Variations Figure 13 – Distribution of pressure (in mb) for January month 4.3.2. Coriolis Force 4.3.3. Centripetal Force 4.3.4. Frictional Force 4.4. Geostrophic Wind Figure 16 – forces governing air movement: (a) geostrophic balance between pressure gradient and Coriolis force; (b) the additional effect of frictional force on surface wind 4.5. Distribution of Pressure Belts Figure 17 – (a) global pressure belts and (b) shifting of pressure belts 4.7. General Circulation of the Atmosphere 4.7.1. Planetary Winds 4.8. Local Winds 4.8.1. The Land and Sea Breezes 4.8.3. Hot Local Winds 4.8.4. Cold Local Winds 4.9. Upper Air Circulation Figure 21 – different vertical temperature gradients in the two columns create an increasing pressure gradient.Figure 22 – jet streams: (a) maximum speed at centre; (b) Polar and subtropical jetstreams in both hemispheres; (c) cross-sectional view of jet streams The polar front jet stream Figure 23 – origin of the Polar front Jet stream at polar front zone Sub-tropical jet stream Consequence of Jet Stream 5. Air Mass Figure 25 – Airmasses 6. Fronts Table 3 – difference between frontogenesis and frontolysis Figure 26 – Fronts: (a) Warm front; (b) Cold front 6.3. Stationary Front 6.4. Occluded Front Figure 27- cold front occlusion and warm front occlusion Figure 28 – symbols used for Fronts 7.1. Extra-Tropical Cyclones Figure 29 – life cycle of a extra-tropical cyclone Figure 30 – world: pathways of cyclones (Numbers indicate average frequency of cyclones)7.2. Tropical Cyclones Figure 31 – tropical cyclone Figure 32 – different names of tropical cyclone Impact on humans Table 7 – comparison between tropical and extra-tropical cyclone Figure 33 – three stages in the development of a thunderstorm: (a) cumulus stage; (b) Mature stage; (c) Dissipating stage 7.3.2. Why Thunders are Cause of Concern