f2 climate concepts & climate zones ihb12...microsoft powerpoint - f2 climate concepts &...

Cli t t & li tClimate concepts & climate zones

Internationellt Hållbart ByggandeErik Johansson, HDM, 2012

Contents

Climate elements Climate zones Exercise: climate analysis

Erik Johansson, HDM 2

Climatic elements

Solar radiation (shortwave) Thermal radiation (longwave)

Cloud cover Cloud cover Temperature Rainfall

H idit Humidity Wind


The sun-atmosphere-earth psystem

18 jan-10 Erik Johansson, HDM 5

The atmosphere

Total height: 100 km (Earth’s radius = 6400 k )km)

Ozone layer: 15 – 35 km altitude The troposphere

f Lower part of the atmosphere: 8–18 km above the Earth’s surface

Temperature from +15 (Earth) to –53°C (upper boundary)


The troposphere

Is the zone where “weather” occurs: winds, clouds, water, pollutionContains 75% of the mass of the Contains 75% of the mass of the atmosphere: nitrogen, oxygen, water, carbon dioxide (CO2), ozone


Short- and longwave radiation Sun: shortwave radiation: 0.1-3 µm

Ultra violet (UV) radiation Ultra violet (UV) radiation Visible light

Earth: longwave radiation: infrared radiation (IR), 3-80 µmg ( ) µ “Low” temperature radiation


Heating and gcooling of the earth


Ways to measure solar yradiation

Sunshine duration (hours) Energy/time and surface units

Daily total irradiation (MJ/m², day) Continuous (hourly) irradiation (W/m²) Continuous (hourly) irradiation (W/m )

(1 W/m² = 1 J/s,m²)


Sunshine duration Piteå, 65°N (northern Sweden)

Dec: 0 June: 10

Los Angeles, 34°N Jan: 7 July: 12

Kuala Lumpur, 3°Np , Dec: 5 June: 7


June: 7

Hourly radiation

Solar radiation in Fez MoroccoW/m²

(on a horizontal surface)

Solar radiation in Fez, Morocco1000W/m

Summer800

SummerWinter

400

600

200

400

0

Erik Johansson, HDM 1500:00

03:00

06:00

09:00

12:00

15:00

18:00

21:00

00:00

Thermal radiation (low temp.) All bodies radiate heat according to

th f lthe formula:42 )(W/m TQ

where T (K) = T(°C)+273

)(Q

( 5 67 10 8 W/ 4K 0 9)( = 5.67·10-8 W/m4K, 0.9)


Radiation of heat

S f R di tiSurface temperature

Radiation (W/m²)

0°C 280

20°C 38020 C 380

40°C 490


Daytime heating of the air

SW–LW radiation convection

conductionErik Johansson, HDM 18

conduction

Surface absorptivity

Reflectivity (albedo) of different y ( )surfaces Bare soil: 5–40% (dark/light) Forest 5–20% Forest 5 20% Grass 16–26% (long/short) Fresh snow: 95%


Cooling by night

LW radiation convection

conduction


Effect of clouds

Less incoming solar radiation – lower heating by dayLess outgoing longwave radiation Less outgoing longwave radiation –lower cooling by night


Diurnal temperature variations

l dclear day

cloudy day


Humidity

Air contains water vapour Ways to measure humidity in the air:

Relative humidity (% of saturation) Absolute humidity (g moisture/kg air) Absolute humidity (g moisture/kg air) Vapour Pressure (hPa)


Max. moisture content vs. air temperature


Relative humidity

Ab l tAbsolute humidity (g/kg)(g/kg)

Temperature (°C)Erik Johansson, HDM 26

Temperature (°C)

Relative humidity

Ab l tAbsolute humidity (g/kg)(g/kg)

Temperature (°C)Erik Johansson, HDM 27

Temperature (°C)

Winds

Winds blow from higher to lower pressuresThe wind direction is modified due to The wind direction is modified due to the Earth’s rotation, friction at the Earth’s surface, etc.


Winds: global circulations


Winds: monsoons

The result of temperature differences of the continents and the oceans4 5 months N direction 4 5 months S 4-5 months N direction, 4-5 months S direction


Area affected by the ymonsoons


Summer monsoon


Winter monsoon


Local sea breeze

Sunny afternoons


Ocean currents


El Niño

Varmare strömmar i östra Stilla havet runt jultidVarmare ytvatten mer regn i västra Varmare ytvatten mer regn i västra Sydamerika

Starka El Niño-år kan påverka klimatet på hela jordenpå hela jorden


La Niña

Motsatsen till El Niño (kallare strömmar) Vindarna från Stilla havet mot Australien

är starkareär starkare Mer vatten förs mot Australiens kust – Mer vatten förs mot Australiens kust

kraftig molnbildning Australiska kontinenten får betydligt mer

nederbörd (Sydamerika får torka)Erik Johansson, HDM 38

( y )

Greenhouse gases

Water vapour Carbon dioxide (CO2) Methane

Nitro s o ides Nitrous oxides Ozone Ozone CFCs


Climate zones


Parameters affecting climate gzones

Latitude Altitude Low and high pressure zones

Global ind patterns Global wind patterns Proximity to oceans and large seas Proximity to oceans and large seas Ocean currents


Latitude zones

Tropic of Capricorn: -23.5°

Tropic of Cancer: +23.5°


Incoming and outgoing g g gradiation at different latitudes


Latitude zones

Low latitudes: 0-30°N/S Mid-latitudes: 30°N/S-60°N/S High latitudes: >60°N/S


High latitudes: >60 N/S

Köppen’s climate classification

Main catagories:A. Equatorial (warm humid)B Arid (hot dry)B. Arid (hot dry)C. TemperateD. Cold temperateE ArcticE. ArcticH. Mountain climates


Köppen’s climate classification


Atkinson (Modified Köppen)1. Cold2. Temperate (moderate)3. Hot dry

Maritime desert climate4. Warm humid

Warm humid island climate Sub-types:

Composite/monsoon climate Tropical highland climate


Simplified climate zoneSimplified climate zone classification according to Köppen


1 – Cold

Moscow (Russia), 56°NErik Johansson, HDM 52

( ),

2 – Temperate

Rome (Italy), 42°NErik Johansson, HDM 53

( y),

4 – Warm humid (equatorial)

Brazzaville (Congo), 4°SErik Johansson, HDM 54

( g ),

Warm humid (monsoon)

Bombay (India), 18°NErik Johansson, HDM 55

y ( ),

3 – Hot dry (arid)

Alice Springs (Australia), 23°SErik Johansson, HDM 56

p g ( ),

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