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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
Erik Johansson, HDM 4
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)
Erik Johansson, HDM 6
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
Erik Johansson, HDM 7
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
18 jan-10 Erik Johansson, HDM 9
Heating and gcooling of the earth
18 jan-10 Erik Johansson, HDM 11
Heating and gcooling of the earth
18 jan-10 Erik Johansson, HDM 12
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)
Erik Johansson, HDM 13
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
Erik Johansson, HDM 14
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)
Erik Johansson, HDM 16
Radiation of heat
S f R di tiSurface temperature
Radiation (W/m²)
0°C 280
20°C 38020 C 380
40°C 490
Erik Johansson, HDM 17
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%
Erik Johansson, HDM 19
Cooling by night
LW radiation convection
conduction
Erik Johansson, HDM 20
Effect of clouds
Less incoming solar radiation – lower heating by dayLess outgoing longwave radiation Less outgoing longwave radiation –lower cooling by night
Erik Johansson, HDM 22
Diurnal temperature variations
l dclear day
cloudy day
Erik Johansson, HDM 23
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)
Erik Johansson, HDM 24
Max. moisture content vs. air temperature
Erik Johansson, HDM 25
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.
Erik Johansson, HDM 28
Winds: global circulations
18 jan-10 Erik Johansson, HDM 29
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
Erik Johansson, HDM 30
Area affected by the ymonsoons
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Summer monsoon
18 jan-10 Erik Johansson, HDM 32
Winter monsoon
18 jan-10 Erik Johansson, HDM 33
Local sea breeze
Sunny afternoons
Erik Johansson, HDM 34
Ocean currents
18 jan-10 Erik Johansson, HDM 35
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
Erik Johansson, HDM 37
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 )
Heating and gcooling of the earth
18 jan-10 Erik Johansson, HDM 40
Greenhouse gases
Water vapour Carbon dioxide (CO2) Methane
Nitro s o ides Nitrous oxides Ozone Ozone CFCs
Erik Johansson, HDM 41
Climate zones
Erik Johansson, HDM 42
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
Erik Johansson, HDM 44
Latitude zones
Tropic of Capricorn: -23.5°
Tropic of Cancer: +23.5°
Erik Johansson, HDM 45
Incoming and outgoing g g gradiation at different latitudes
18 jan-10 Erik Johansson, HDM 46
Latitude zones
Low latitudes: 0-30°N/S Mid-latitudes: 30°N/S-60°N/S High latitudes: >60°N/S
Erik Johansson, HDM 47
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
Erik Johansson, HDM 48
Köppen’s climate classification
Erik Johansson, HDM 49
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
Erik Johansson, HDM 50
Simplified climate zoneSimplified climate zone classification according to Köppen
Erik Johansson, HDM 51
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 ( ),