COMPONENTS, ELEMENTS AND CONTROLS OF CLIMATE (Lecture 1)

Spatial variations in climate Climate as a system

Temporal variations in climate (Seasonal) Climate as a system

Temporal variations in climate (Seasonal) Climate as a system

Long-term changes in climate Climate as a system

Components of the Climate System

Radiation Scattering and Albedo

Eccentricity (orbital stretch) Shape of Earths yearly path around sun Earths orbit is not perfectly circular: elliptical shape Orbit shaped by gravitational pull of planets Eccentricity is NOT constant (~100ky & 400ky) Eccentricity is SECONDARY reason for seasons

Eccentricity (orbital stretch) Affects amount of energy reaching Earth!

Obliquity (axial tilt) The tilt of axis of rotation relative to the plane of the Earths orbit about the Sun

Obliquity (axial tilt) Obliquity NOT constant: 22.1°-24.5° variation (~41ky) Affects global distribution of solar energy!

Obliquity (axial tilt) The PRIMARY cause of the seasons

Simple Change in Axial Tilt No tilt, solar radiation always over equator No seasonal change in solar radiation Solstices and equinoxes do not exist 90° tilt, solar radiation hits poles Day-long darkness Day-long light Extreme seasonality

Precession (Earth wobble) Earths spin axis wobbles, gradually leaning in different directions (direction of leaning or tilting changes through time)

Precession (Earth wobble) Caused by gravitational pull of Sun + Moon One circular path takes 25,700 years Earths rotational axis points in different directions through time

Precession (Earth wobble) Earths wobble and rotation of its elliptical orbit produce precession of the solstices and equinoxes One cycles takes 23,000 years

Precession (Earth wobble) Affects climate by changing the global distribution of solar energy Today VS 11,500 yrs ago

OVERALL CLIMATIC EFFECT OF ORBITAL CHANGES

Sunspots and Dustclouds Sunspot:

END LECTURE 1

CONTROLS OF CLIMATE (Lecture 2)

Climate as a System

Pressure DECREASES with height! (Think: swimming pool)

Energy and the Atmosphere Solar Radiation EARTH Atmosphere

Energy and Latitude

Vs.

Perpendicular Surfaces get More…

Energy and Latitude

Daily changes in insolation at the Earths surface The sun does not get bigger/hotter throughout the day… It just changes position!

How does differential heating cause climate zones?

Hadley Cells (super simple version)

Hadley Cells (simple version) What causes multiple cells? Why do winds curve? What do all these have to do with climate and climate zones?

End Lecture 2

CONTROLS OF CLIMATE Part 2 (Lecture 3)

Hadley Cells (super simple version)

Hadley Cells (simple version) What causes multiple cells? Why do winds curve? What do all these have to do with climate and climate zones?

Coriolis Force Effect

Coriolis, winds and cloud patterns

Hadley Cells (simple version)

Convergent/Divergent Zones Convergent Divergent (at Earths surface)

3 Main Pressure Belts Easterlies Westerlies Trade Winds

ITCZ

ITCZ and Equatorial Rainforests

Polar Front

Polar Fronts and Boreal Forests

Subtropical High

Subtropical Highs and Deserts

Polar Highs and Tundra Why isnt it a desert in the N and S poles? 1. Not enough sunlight… 2. Thinner atmosphere

Putting it all together…

Points to Ponder… Why are deserts/forests patchy instead of stripy? Why are some glaciers found in rainforests and some rainforests found in deserts?

End Lecture 3 Next lecture: Regional/Local Controls of Climate

REGIONAL AND LOCAL CONTROLS OF CLIMATE (Lecture 4)

Hadley Cells and Global Climate

0°0°30°60°90° N. Pole 30°60° 90° S. Pole All seasons wet All seasons dry All seasons wet All seasons dry

Non-uniformity of Global Climate Why patchy and not stripy? LISBON, PT OMAHA, NE, USA

Non-uniformity of Global Climate Lisbon, PT: (Latitude 38°N) Avg. Min. Temp. = 8°C (Jan) Avg. Max. Temp. = 28°C (Aug)

Non-uniformity of Global Climate Omaha, NE, USA: (Latitude 41°N) Avg. Min. Temp. = -6°C (Jan) Avg. Max. Temp. = 23°C (Aug)

Water takes longer to heat than land

Water has a moderating effect on land temperature

Water takes longer to cool than land

Water has a moderating effect on land temperature

Water Moves Heat To/From Areas

Thermohaline Circulation 1. Sun heats water around the equator 2. Surface currents take warm water north (N. Atlantic)

Thermohaline Circulation 3. Surface water cools as it heads to high latitudes (heat released to the atmosphere) 4. Cool/salty water sinks and heads south

Thermohaline Circ. is what keeps Western Europe warm! Dublin, IEMinsk, BY

Lyon, FR Lucerne, CH

201 meters436 metersElevation

End Lecture 4 Next lecture: More Regional/Local Controls of Climate

MORE REGIONAL AND LOCAL CONTROLS OF CLIMATE (Lecture 5)

0°0°30°60°90° N. Pole 30°60° 90° S. Pole All seasons wet All seasons dry All seasons wet All seasons dry

3 Main Pressure Belts Easterlies Westerlies Trade Winds

GULF STREAM KEEPS WESTERN EUROPE WARMER THAN IT OUGHT TO BE (CONSIDERING LATITUDE)

Land-Sea Night Temp. Differences

NIGHT TIME THERMAL INFRARED IMAGE SHOWING : WATER WARMER THAN LAND

More Regional/Local Climate Factors

Seattle, WA Yakima, WA

More Regional/Local Climate Factors

The Influence of Topography on Climate 1. Promoting convection Cooler Air Warm Air

2. Forcing air to rise along windward slopes AIR MASS PREVAILING WIND DIRECTION OROGRAPHIC UPLIFT: The vertical forcing of air by terrain features such a hills or mountain The Influence of Topography on Climate

Orographic Uplift and Climate Uplifted air cools and releases moisture contents AIR MASS PREVAILING WIND DIRECTION Precipitation greater if air mass is from a water body

Aspect and Climate Uplifted air (now dry) crosses ridge and descends… Air heats adiabatically Hot, dry air continues onward… 3. Forcing air to sink along leeward slopes

Aspect and Climate Wet, windward aspect VS. Dry, leeward aspect (RAINSHADOW) Rainshadow: An area of diminished precipitation on the lee side of mountains

Karijini National Park, W. Australia

Complex Combinations of Topo + H 2 O…

WINTER Prevailing Winter Winds

LAKE EFFECTS

End Lecture 5 Next lecture: Urban Climates and Mans Effect on Climate

REGIONAL AND LOCAL CONTROLS OF CLIMATE: URBAN CLIMATES (Lecture 6)

Surface Type: Urban Surface and Insolation

Different surfaces have different albedos Different capacities to absorb insolation Surface~Albedo Snow0.98 Grassy field0.20 Farmland0.15 Swampland0.14 Asphalt0.07 Ocean0.03

Surface Type: Urban Surface and Insolation

Surface~Specific Heat (J/kg·K) Water (at 0°C)4218 Wet soil1480 Asphalt920 Concrete880 Brick840 Tin228 Surface Type: Urban Surface and Insolation

Evapotranspiration (ET) = Evaporation (E) + Transpiration (T)

The majority of clouds over rainforests are generated by rainforests Less rainforests less clouds less albedo warmer temperatures

Forward looking infrared (FLIR)

(Relatively) Natural Landscape Urban Landscape

Urban Structures

Day: Insolation channelled and trapped

Night: Thermal energy channelled and trapped

Wind flow hindered Advection diminished

Urban heat islands Most cities show a large heat island effect, registering 5–11°C warmer than surrounding rural areas

Urban heat islands dark surfaces such as asphalt roads or rooftops can reach temperatures 30–40°C higher than surrounding air

End Lecture 6 Next lecture: Urban Pollution and Urban Climate Climate Classification (bring pillows)

Urban Climate (Pollution) & Climate Classification Systems

Urban Heat Island

Surface Type and Radiation Balance

Effect of Atmosphere on Radiation Balance

Particulate matter in the atmosphere tend to reflect insolation Cools the Earths surface

Effect of Atmosphere on Radiation Balance Particulate matter in the atmosphere tend to absorb and re-radiate thermal energy Warms the Earths surface

How Greenhouses Work Result: Interior of greenhouse warms 1. Glass walls/ceilings allow short-wave radiation (i.e. light) into greenhouse (1) 2. Radiation absorbed by ground/objects in the greenhouse, which then re- radiate it as long-wave radiation (i.e. heat) (2) 3. Glass walls/ceilings prevent long-wave radiation from leaving (3)

How greenhouse gases work

Effect of Atmosphere on Radiation Balance Human activity adds more particulate matter and GHGs into the atmosphere Air pollution affects climate globally and causes other environmental damage (e.g. acid rain, water pollution, etc.)

Urban climates are especially affected because air pollution concentrated over urban landscape Effect of Atmosphere on Radiation Balance Bogotá, CO Los Angeles, US

Effect of Atmosphere on Radiation Balance GHGs/Particulate Matter Urban-generated heat Heat absorbed and re-radiated

Climate Classification Systems

Climate/weather stations in IE

End Lecture 7 Next lecture: More Climate Classification

More Climate Classification Systems

Group A

Group B Desert Steppe

Group C Med. Humid Sub-Trop Maritime Temperate Maritime Sub-Arctic

Group D Opposite Extreme Temperatures Throughout Year

Group E Et Ef

Major Climate Groups (Koppen System)

End Lecture 8 Next lecture: Finish Climate Systems… Monsoons

K ö ppen System & Monsoon Climate

Major Climate Groups (Koppen System)

Monsoon Climate

Water takes longer to heat than land Sea Breeze

Water takes longer to cool than land Land Breeze

Asian Monsoon

When would be the best time to climb Mt. Everest: Winter or Summer?

North American Monsoon

African Monsoon Two peaks: 1)Late spring (May/Jun) 2)Late summer (Jul/Aug)

End Lecture 9 Next lecture: Climate & Human Physiology

Climate & Human Physiology Comfort and Clothing

Climate and Physiology

Wind Chill Wind chill (not wind chill factor): The apparent temperature felt on exposed skin due to the combination of air temp and wind speed

Effects of Humidity Heat Index (HI): index that combines actual air temperature and relative humidity to determine an apparent temperature

End Lecture 10 Next lecture: Clothing and Survival in Extreme Climates Climate & Agriculture/Horticulture

Climate & Human Physiology Comfort and Clothing

Clothes can impact your survival in extreme climates

Clothing and Survival in Extreme Climates Heat gain in desert: 1. Direct insolation 2. Reflected insolation 3. Conductive heat gain 4. Advective/Convective heat gain

Clothes can impact your survival in extreme climates

Clothing and Survival in Extreme Climates

Clothes can impact your survival in extreme climates

Climate & Agriculture

End Lecture 11 Next lecture: Climate & Agriculture/Horticulture

Climate & Horticulture

Wind Wind-sensitive crops (e.g. vines/grapes) ideally situated in relatively wind- calm areas Ex: S. Australia Central California S. France If located in wind-prone areas, climate must be modified (e.g. the use of windbreaks)

End Lecture 12