5. CLIMATE:
• THE CHARACTERISTIC PATTERN OF
WEATHER CONDITIONS WITHIN A
REGION
• INCLUDES:
• TEMPERATURE, WIND VELOCITY,
PRECIPITATION, AND OTHER FEATURES -
AVERAGED OVER A LONG PERIOD OF
TIME
6. CLIMATE
• DEFINITION
• THE CLIMATE OF A REGION IS ITS LONG-TERM WEATHER. THE TWO MAIN CHARACTERISTICS OF CLIMATE
ARE TEMPERATURE AND PRECIPITATION, WHICH CAN BE DESCRIBED BY AVERAGES AND RANGES.CLIMATE
• CLIMATE CONTROLS
• MANY OTHER FACTORS ACT TOGETHER TO DETERMINE EARTH’S CLIMATE: LATITUDE, ELEVATION,
DISTANCE FROM LARGE BODIES OF WATER, OCEAN CURRENTS, TOPOGRAPHY,PREVAILING WINDS, AND
VEGETATION.
7. CLIMATE ZONES
• THE WORLD IS DIVIDED INTO
5 MAJOR CLIMATE ZONES
BASED ON:
• AVERAGE MONTHLY
TEMPERATURE AND
PRECIPITATION
• AVERAGE ANNUAL
PRECIPITATION
Climate Zone Description
1. Tropical moist climate All months average above 18 ∘ C
Annual precipitation greater than
1500 mm
2.Dry climate Temp range from 40 ∘ C to - 40 ∘ C
Low precipitation, exceeded by
evaporation
3. Moist, mid- latitude climate
with mild winters
Warm to hot summers No colder
than -3 ∘ C on average in cold
months
4. Moist, mid- latitude climate with
cold winters
Warm to cool summers Average
below -3 ∘ C in colder months
5. Polar climate Cool summers and extremely cold
winters
8. • FACTORS THAT AFFECT CLIMATE CHANGE CLIMATES AROUND THE WORLD HAVE CHANGED MANY TIMES
OVER THE BILLIONS OF YEARS OF EARTH’S HISTORY MANYNATURAL FACTORS AFFECT CLIMATE CHANGE.
9. FACTORS THAT AFFECT CLIMATE
• 1. THE SUN
• 2. THE ATMOSPHERE AND WIND
• 3. THE HYDROSPHERE
• 4. THE MOVEMENT OF CONTINENTS
• 5. DISTANCE TO LARGE BODIES OF WATER
10. 1. THE SUN
• THE SINGLE MOST IMPORTANT FACTOR THAT AFFECTS CLIMATE ON EARTH
• ENERGY TRAVELS TO EARTH IN FORM OF LIGHT AND HEAT
• AFFECTS TEMPERATURE, PRECIPITATION AND WIND
FOUR FACTORS:
• A. CHANGES IN SOLAR ACTIVITY
• B. MOVEMENTS OF EARTH IN SPACE
• C. CHANGES IN EARTH’S ROTATION, ORBIT AND TILT
• D. LATITUDE
11. 1A. SOLAR ACTIVITY
• AMOUNT OF SOLAR RADIATION VARIES WITH
IRREGULAR FLUCTUATIONS
• THERE IS ALSO A REGULAR SOLAR CYCLE (SUNSPOT
CYCLE)
• VARIATIONS IN SOLAR OUTPUT HISTORICALLY HAVE
BEEN ATTRIBUTED TO BE THE MAIN CAUSE OF CLIMATE
CHANGE
12. 1B.MOVEMENTS OF EARTH IN SPACE
• EARTH ROTATES ON ITS AXIS EVERY 24
HOURS EARTH ORBITS AROUND THE SUN
EVERY 365 DAYS EARTH IS TILTED AT AN
ANGLE OF 23.5 ALL OF THESE FACTORS
PRODUCE THE SEASONS.
13. 1C.ROTATION, ORBIT AND TILT :
• ECCENTRICITY: DUE TO GRAVITATIONAL
ATTRACTION OF OTHER PLANETS, EARTH’S
ORBIT FLUCTUATES SLIGHTLY FROM
CIRCULAR TO ELLIPTICAL (CYCLE OF
100000 YEARS)
• TILT: ANGLE OF TILT VARIES BY 2.4 EVERY 41
000 YEARS
• GREATER THE ANGLE = GREATER THE
DIFFERENCE BETWEEN WINTER & SUMMER
Circular Orbit
Elliptical Orbit
14. 1C.ROTATION, ORBIT AND TILT :
• WOBBLE:
• EARTH IS NOT A PERFECT SPHERE, SO IT
WOBBLES SLIGHTLY AS IT ROTATES ON ITS
AXIS.
• AFFECTS AMOUNT AND INTENSITY OF
SOLAR ENERGY RECEIVED AT DIFFERENT
PARTS OF THE YEAR
15. 1D. LATITUDE
• SUN’S RAYS STRIKE THE EARTH AT DIFFERENT ANGLES
DUE TO ITS CURVED SHAPE
• THERE THE SAME AMOUNT OF SOLAR RADIATIONS
HITTING THE EARTH AT THE POLES AS AT EQUATOR, BUT
AT THE POLES THE RADIATIONS ARE LESS
CONCENTRATED DUE TO THE CURVATURE OF THE
EARTH.
16. 1D. LATITUDE
• AT THE EQUATOR, RAYS STRIKE
DIRECTLY PERPENDICULAR TO SURFACE
AT LATITUDE OF 45O SOUTH, RAYS
STRIKE AT AN ANGLE, SO ENERGY IS
SPREAD OUT OVER A GREATER DISTANCE
17. 2. THE ATMOSPHERE AND WIND
• THE ATMOSPHEREEXTENDS UP FROM SURFACE TO 560
KM INTO SPACE
• COMPOSED MAINLY OF NITROGEN GAS, OXYGEN GAS
AND WATER VAPOUR
• ABSORBS THERMAL ENERGY FROM THE SUN AND FROM
EARTH’S SURFACE = GREENHOUSE EFFECT HELPS TO
KEEP TEMPERATURE VARIATIONS WITHIN A CERTAIN
RANGE
18. ROLE OF WIND:
• WIND: MOVEMENT OF AIR FROM AREA OF HIGH
PRESSURE TO AREA OF LOW PRESSURE
• WINDS DISPERSE ENERGY THROUGH
ATMOSPHERE
WIND TRANSFERS THERMAL ENERGY FROM
WARM TO COOL AREAS (HIGH TO LOW
PRESSURE)
19. ROLE OF WIND
• WINDS MOVE OCEAN CURRENTS
• AS WINDS MOVE ACROSS THE SURFACE OF
WATER, ENERGY IS TRANSFERRED TO THE
WATER, CAUSING WATER TO MOVE
• WATER ABSORBS ENERGY FROM THE SUN -
MOVEMENT OF WATER RESULTS IN
TRANSFER OF HEAT AROUND EARTH’S
SURFACE PREVAILING GLOBAL WIND
PATTERNS AND OCEAN CURRENTS
21. III) WINDS AFFECT PRECIPITATION
• AS AIR MASSES MOVE ACROSS EARTH’S
SURFACE, THEY INTERACT
• ONE MASS (THE LIGHTER ONE) USUALLY
RISES ABOVE THE OTHER
• RISING AIR COOLS AND WATER VAPOUR
IN THE AIR CONDENSES TO FORM
PRECIPITATION
22. III) WINDS AFFECT PRECIPITATION
• JET STREAMS:
• HIGH ALTITUDE WINDS THAT TRAVEL AT
HIGH SPEED MAY CARRY WARM, MOIST AIR
(CAUSES PRECIPITATION) OR DRY, COOL AIR
(CAUSES DRY WEATHER)
24. 3. THE HYDROSPHERE
• HYDROSPHERE: ALL WATER FOUND ON, UNDER AND OVER THE
SURFACE OF EARTH IN THE FORM OF LIQUID WATER, ICE OR VAPOUR
• OCEANS HOLD MUCH MORE HEAT THAN THE ATMOSPHERE ACT AS A
HEAT RESERVOIR
• A LOT OF ENERGY IS REQUIRED TO CHANGE THE TEMPERATURE OF
WATER BY EVEN ONE DEGREE CELSIUS
• TEMPERATURE OF LARGE BODIES OF WATER CHANGES SLOWLY AND
BY SMALL AMOUNTS
25. 3. THE HYDROSPHERE
• ICE AND SNOW REFLECT SOLAR RADIATION BECAUSE OF THEIR LIGHT
COLOUR
• ALBEDO:
• THE FRACTION OF ENERGY REFLECTED BY A SURFACE (LARGELY
DETERMINED BY COLOUR)
• A LARGE SURFACE OF SNOW OR ICE WILL REFLECT UP TO 80 OR 90% OF
THE SOLAR ENERGY THAT STRIKES IT
• IN COMPARISON, THE OCEAN SURFACE REFLECTS ONLY 7% THE
DISTRIBUTION OF WATER, ICE & LAND GREATLY AFFECTS TEMPERATURE
26. 4. THE MOVING CONTINENTS
• EARTH’S OUTER LAYER IS COMPOSED OF MASSIVE PIECES OF ROCK CALLED TECTONIC PLATES
• THE PLATES MOVE AT A RATE OF A FEW CM EACH YEAR, CARRYING CONTINENTS WITH THEM
• SHAPE OF OCEANS AND CONTINENTS IS ALWAYS CHANGING SLIGHTLY, AFFECTING PATTERNS OF HEAT
TRANSFER THROUGH AIR AND WATER
27. 4. THE MOVING CONTINENTS
• VOLCANOES ARE LOCATED AT BOUNDARIES OF TECTONICPLATES
• WHEN VOLCANOES ERUPT, ASH AND OTHER PARTICLES ARE SPEWED
INTO THE ATMOSPHERE PARTICLES REFLECT SOLAR RADIATION AND
COOL THE CLIMATE
• EFFECT MAY LAST A FEW YEARS TO SEVERAL DECADES
28. 5. DISTANCE FROM LARGE BODIES OF
WATER
• LARGE BODIES OF WATER, SUCH AS LAKES AND OCEANS,
CAN AFFECT THE TEMPERATURE OF AN AREA BECAUSE
THE TEMPERATURE OF THE WATER BODY INFLUENCES
THE TEMPERATURE OF THE AIR ABOVE IT.
• TEMPERATURESOF NEARBY LANDS ARE LESS EXTREME.
29. OCEAN CURRENTS
• OCEAN CURRENTS HELP TRANSFER HEAT TO THE ATMOSPHERE.
• SOME WARM OCEAN CURRENTS MOVE WATER FROM THE
EQUATOR TOWARDS THE POLES AND WARMS THE AIR ABOVE IT.
THE WARM AIR MOVES OVER TO THE NEARBY LAND.
• AT THE SAME TIME, COLD CURRENTS BRING COLD WATER FROM
THE POLAR ZONES TOWARDS THE EQUATOR. AS IT MOVES, IT
BRINGS COOL AIR.
• MARINE CLIMATES ARE INFLUENCED BY OCEAN CURRENTS.
Editor's Notes
sunspot cycle: All cycles within solar system moves from maximum to min value and then back to max and min over a period of years
