Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
TELEMATIC TEACHING PROJECT Climate and Weather [email protected] GLOBAL AIR CIRCULATION •High and Low pressures •Circulation patterns HIGH AND LOW PRESSURES GLOBAL AIR CIRCULATION PATTERN •Warm & cold air meet •LOW PRES •Very cold •Decending air •HIGH PRES Polar high Western winds Tropical easterlies •Very hot •Ascending air •LOW PRES Tropical easterlies Western winds Polar high Winds deflect to the RIGHT in NH and to the LEFT in SH •Air from Equator sinks •HIGH PRES MID LATTITUDE CYCLONES •Cold & warm fronts •Stages •Weather changes MID LATTITUDE CYCLONES: CONCEPTS WARM FRONT COLD FRONT MIDLATTITUDE CYCLONE: DEVELOPMENT 1 INITIAL STAGE 2 DEVELOPMENT STAGE 3 MATURE STAGE 4 OCCLUSION FAMILY OF CYCLONES MID-LATTITUDE CYCLONE Cold front Isobar Warm sector L Cold sector Wind rotation clockwise WEATHER CHANGES COLD FRONT Cold front NW Wind SW Wind Warm front WEATHER CHANGES: COLD FRONT Movement of cyclone •SW-wind •Low temp •High cloud cover •Precipitation •LP •NW-wind •High temp •Few/no clouds •No precipitation •HP LP TROPICAL CYCLONES •Characteristics •Stages •How managed TROPICAL CYCLONES TROPICAL CYCLONES CHARACTERISTICS Equator/Ewenaar From EAST to WEST EYE No wind, rain & Clouds DESTRUCTION •Storm winds •Torrential rain •Flooding Turns EAST at 30° DISSIPATES •No Moisture •No warm air •Friction TROPICAL CYCLONE: DEVELOPMENT INITIAL pressure ABOVE 1000 hPa MATURE pressure WELL BELOW 1 000hPa IMMATURE Pressure BELOW 1 000 hPa DISSIPATION pressure RISES TROPICALCYCLONE - MANAGEMENT TROPICAL CYCLONES NAME Alphabet Andrew Bonny Carl Debora IN EYE No : Wind Clouds Rain ORIGEN In tropics OCEANS Not nearer than 5° from equator WEATHER Before eye During eye After eye MOVEMENT From E na W Away from Equator Turns east at 30° DESTRUCTION Storm winds Very hard rain Flooding DISSIPATION Over land No Moisture No Warm air Friction MANAGED Sand bags Early warning Track storm Services Inform people Evacuation EXAMINATION QUESTION •Coriolis force •Warm water •Moisture Tropical easterlies •Land •No warm water •Friction 1 2 3 4 5 Give ONE similarity between Hurricanes and Tropical cyclones on the map. Explain the point of origin of both hurricanes and tropical cyclones on the map. Why do these cyclones move from east to west? Why do tropical cyclones weaken as they move over Madagascar. Why is the impact of tropical cyclones more severe in developing countries? REGIONAL CLIMATE •Line thunderstorms •Berg winds LINE THUNDERSTORMS WARM MOIST AIR COLD DRY AIR H H HEIGHT OF INVERSION SOUTH AFRICAN BERGWIND Anti clockwise circulation High pressure in interior H Descending air heated Danger: Veldfires Warm dry wind at coast Low pressure L over sea EXAMINATION QUESTION DRY – FROM INTERIOR 1 2 3 4 5 6 WARM & DRY Name the high pressure cell visible on the diagram. During what season do berg winds affect the weather of South Africa? How does the wind in the diagram affect the weather along the coast of SA? Explain why these weather conditions mentioned in question 3 occur. Name the environmental hazard associated with berg wind conditions. How are berg winds terminated (ended)? VALLEY CLIMATES •Aspect •Inversions VALLEY CLIMATES ASPECT (SH) S O U T H WARMER NO SNOW SNOW COLDER N O R T H INVERSIONS INSOLATION Radiation faster if no clouds During day – land heated In night surface cools off WARM AIR POLUTED AIR TRAPPED Air close to surfacecooler Cold air decends URBAN CLIMATES •Characteristics of urban climate •Heat Islands CHARACTERISTICS OF CITY CLIMATES Why are cities warmer than rural areas? BUILDINGS EXAMINATION QUESTION 1 2 3 4 What is a heat island? Which part of the city is experiencing the highest temperature? How have peoples lives been changed by heat islands. Whet can be done to reduce high temperatures in cities? SYNOPTIC WEATHER MAPS •Station models •Interpretation WEATHER STATION MODEL WIND DIRECTION TEMPERATURE 20 N W 18 E S DEW POINT TEMPERATURE WIND SPEED 10 Knots 15 Knots 5 Knots SYNOPTIC WEATHER MAPS TRANSITIONAL PAGE TRANSITIONAL PAGE