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8th lecture

Realistic magnitude of terrestrial radiation Computation (Schwarzschild equation) Modern method for measuring Long-wave irradiance How to integrate the theory into climate models. 8th lecture. Highlights of the last week : Terrestrial (long-wave) radiation. Possible Range.

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8th lecture

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  1. Realistic magnitude of terrestrial radiation Computation (Schwarzschild equation) Modern method for measuring Long-wave irradiance How to integrate the theory into climate models 8th lecture Highlights of the last week: Terrestrial (long-wave) radiation

  2. Possible Range

  3. Schwarzschild equation for transfer of terrestrial radiation 0 0 Bλ ρkλ δz Bλ is Planck function Iλ Iλ ρkλ δz δz Bλ ρkλ δz Iλ-Iλ ρkλ δz u0 u z Def. Optical mass δu = ρδz

  4. Tλ 1 Tλuo 0 Bλ that it temperature

  5. Several examples of terrestrial incoming radiation with one level T Ångström (1920): Lo = (A - B 10-Ce) σT4 A=0.82, B=0.25, C=0.12, ein mmHg Brunt (1932): Swinbank (1963): Ruckstuhl (2007):

  6. Effect of clouds Where n if the cloud fraction in tenth, k is cloud-type constant, and m is unity. Values of k Ci Cc Cs Ac As Sc St Cu Ohmura 0.08 0.20 0.14 0.24 0.24 0.28 0.28 0.29 Boltz 0.04 0.17 0.08 0.17 0.20 ----- 0.24 0.20

  7. GCM experiments for future climate at 2x CO2 ΔT°C ΔP% NCAR CCM 3.5 +12 GFDL 4.3 +12 GISS 4.5 +16 OSU 3.1 +13 ECHAM5 1.5 +2

  8. Today’s main theme: Total energy balance of the globe and climate simulation.

  9. Mean Energy Budget of the Globe [W m-2] 340 W m-2 102 W m-2 238 W m-2 TOA Kinetic Energy 1.4 MJ m-2 Solar Radiation Longwave Radiation +238 W m-2 -238 W m-2 4.4 W m-2 Static Energy 2620 MJ m-2 Internal Energy 1880 MJ m-2 Potential Energy 740 MJ m-2 (Available potential energy 5.3 MJ m-2) +89 W m-2 Absorption of solar radiation -194 W m-2 Atmospheric net longwave -105 W m-2 Atmospheric net radiation +105 W m-2 20 W m-2 85 W m-2 175 W m-2 26 W m-2 341 W m-2 385 W m-2 BOA +149 W m-2 -44 W m-2 -105 W m-2 +105 W m-2 Surfce net radiation Sensible Heat Flux Latent Heat Flux Global Radiation Reflected Radiation Longwave Downward Longwave Upward

  10. Sensible heat flux ECHAM5 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90W/m**2

  11. (2001-2002)

  12. Annual global net radiation, latent heat of evaporation and precipitation mm a-1 W m-2 100 1300 1200 90 + NCAR/NCEP RA Legates and Willmott Annual global precipitation Annual global latent heat of evaporation ECHAM3 T106 + +ERA15 1100 80 + ECHAM4 T42 + ECHAM4 T106 Jaeger 1000 GPCP + ERA & HOAPS 70 900 120 80 100 90 110 Annual global net radiation in W m-2

  13. Heat balance for the melting surface Net radiation latent heat flux Melt Sensible heat flux Conduction

  14. Su au …. Active layer M al ….. Sl For the upper boundary, Constant Variable Variable Constant Global solar radiation Albedo Longwave atmospheric radiation Sensible heat flux Latent heat flux Sub-surface flux Stefan-Boltzmann constant Surface temperature Latent heat of melt

  15. Mean energy balance on ELA of nine glaciers (W m-2) (3 Arctic, 5 mid-latitude and 1 Equatorial mountain glaciers) 0.59 270 25 -5 -2 309 90 Wm-2 253 ±3 ±5 69% 6% 1% 0.5% 76% 22% 99 25% 75% eq. 272 K Almost 1 : 3 Influence of Temperature Source: Ward Hunt Ice Shelf (Lister, 1962); Meighen Ice Cap (Taylor, 1974); ETH Camp, Greenland (Ohmura et al. 1994); Blue Glacier (LaChapelle, 1959) Vernagtferner (Hoinkes and Untersteiner, 1952; Hoinkes, 1955, Kuhn and Escher- Vetter, 2004); Hintereisferner (Wagner, 1979; Tanzer, 1986); Rhonegletscher (Funk, 1985);Urmuqihe No.1 (Calanca and Heuberger, 1990); Zongo (Wagnon et al.,1999)

  16. TOA Net solar radiation

  17. TOA emission of terrestrial radiation

  18. TOA Net radiation

  19. Fig. 4.3.3.9: Annual average of the effect of clouds on the net radiation budget (in Wm-2) during the period 1991 – 1995, computed as the difference between the mean values in Fig. 4.3.3.2a andthe net radiation at clear skies. Over most areas clouds tend to reduce the net gain of radiative energy by the climate system (negative values), while over some small areas with high and persistent convection they tend to enhance it. Over both Polar Regions this effect is relatively more inaccurate due to large uncertainties in cloud identifications. Highest and lowest values: +13 and -80 Wm-2; global average : -24 Wm-2.

  20. F: meridional heat flux

  21. ERBE Northward transport of energy with ISCCP, compared with ERBE

  22. ECHAM5 T106 over Europe Scenario SRES A2 Winter change

  23. ECHAM5 T106 over Europe Scenario SRES A2 Summer change end of 21th Century

  24. Projected change in summer soil moisture end of 21th Century Scenario A2 cm

  25. Detection of important changes in radiation • Global dimming & brightening • Possible increase in long-wave incoming radiation BSRN trend

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