cli t d r di ticlimate and radiation
TRANSCRIPT
Cli t d R di tiCli t d R di tiClimate and RadiationClimate and Radiation
Yuk Ling YungYuk Ling YungGPS CaltechGPS CaltechGPS CaltechGPS Caltech
Presentation at CaltechPresentation at CaltechAug 31 2009Aug 31 2009gg
Today’s OutlineToday’s OutlineToday s OutlineToday s Outline
What is Radiation? (Review)What is Radiation? (Review)Wh t i th G h Eff t?Wh t i th G h Eff t? ((R i )R i )What is the Greenhouse Effect?What is the Greenhouse Effect? ((Review)Review)GCM Prediction of FutureGCM Prediction of Future (IPCC)(IPCC)Use of Spectral Data ConclusionsConclusions
Blackbody Radiation
( )3
2
2 11h kT
hB Tc eν ν
ν=
−1c e
Goody and Yung (1995)
SSun surface
Center of sun
Atmosphere Space
T
Atmosphere : Processor of energy
Ts
=
Sunlight = driver ofChemistry dynamics{
288Sunlight driver of dynamics
biology{8
K
Process Total Power (Watts)
Sunlight 2 X 1017Sunlight 2 X 10
Seawater evaporation 3 X 1016
Ph t th i 1 X 1014Photosynthesis 1 X 1014
Geothermal flux 3 X 1013
Tides 2 X 1013
Energy use by man (1980) 1 X 1013
UV energy to make O3 layer 1 X 1013
Hydroelectric Power 3 X 1011
Winds 2 X 1011
Volcanoes 4 X 1010
Earthquakes 1 X 1010
Molecules to LifeMolecules to Life
Top of atmosphere
Surface
Top-of-atmosphere
Surface
Top-of-atmosphere
Net DifferencesShortwave
Kiehl and Trenberth 1997
68 100
Today’s OutlineToday’s OutlineToday s OutlineToday s Outline
What is Radiation? (Review)What is Radiation? (Review)Wh t i th G h Eff t?Wh t i th G h Eff t? ((R i )R i )What is the Greenhouse Effect?What is the Greenhouse Effect? ((Review)Review)GCM Prediction of FutureGCM Prediction of Future (IPCC)(IPCC)Use of Spectral Data ConclusionsConclusions
Observational Dataset
• AIRS (Atmospheric Infrared Sounder)AIRS (Atmospheric Infrared Sounder)Lifetime: May 2002 – PresentSpectral coverage: 650-2665 cm-1Spectral coverage: 650 2665 cmSpectral resolution (FWHM): ν/1200 cm-1
Field of view: 13.5 km(~9 times of the FOVs per AMSU-A FOV)SNR: 600-4000Calibration bias: 0.07-0.5 K in BTOrbit: Sun-synchronous, 1:30 PM sampling
S ath Width: 1650 km t ice dail s athSwath Width: 1650 km, twice daily swath
Absorption in Earth’s Atmosphere
H2O
O3
2
H2O
CO2
Greenhouse gases and radianceGreenhouse gases and radiance
• Outgoing thermal infraredOutgoing thermal infrared spectra (W/m2/cm-1/sr) I(v)– Integrand of OLR, containing g , g
many pieces of useful informationF d l li– Fundamental to climate diagnostics
By courtesy of John Dykema
x: Machida et al. [1995] +: Bernard et al. [2006]
Today’s OutlineToday’s OutlineToday s OutlineToday s Outline
What is Radiation? (Review)What is Radiation? (Review)Wh t i th G h Eff t?Wh t i th G h Eff t? ((R i )R i )What is the Greenhouse Effect?What is the Greenhouse Effect? ((Review)Review)GCM Prediction of FutureGCM Prediction of Future (IPCC)(IPCC)Use of Spectral Data ConclusionsConclusions
Today’s OutlineToday’s OutlineToday s OutlineToday s Outline
What is Radiation? (Review)What is Radiation? (Review)Wh t i th G h Eff t?Wh t i th G h Eff t? ((R i )R i )What is the Greenhouse Effect?What is the Greenhouse Effect? ((Review)Review)GCM Prediction of FutureGCM Prediction of Future (IPCC)(IPCC)Use of Spectral Data ConclusionsConclusions
Observational Dataset• IRIS (Infrared Interferometer Spectrometer)
Lifetime: Apr 70 – Jan 71Lifetime: Apr 70 Jan 71 Spectral coverage: 400-1600 cm-1
(in this study, 400-1400 cm-1)Spectral resolution (FWHM): 2.8 cm-1
Field of view: 95km in diameter (~6.25 times of the FOV of ERBE, 15% of an AM2 grid box)SNR: 20~100C lib ti bi 0 25 0 75K i BTCalibration bias: 0.25-0.75K in BTOrbit: Sun-synchronous, 10:30AM/PM sampling
700 000 good spectra over 10 months700,000 good spectra over 10 months
Observational Dataset
• AIRS (Atmospheric Infrared Sounder)AIRS (Atmospheric Infrared Sounder)Lifetime: May 2002 – PresentSpectral coverage: 650-2665 cm-1Spectral coverage: 650 2665 cmSpectral resolution (FWHM): ν/1200 cm-1
Field of view: 13.5 km(~9 times of the FOVs per AMSU-A FOV)SNR: 600-4000Calibration bias: 0.07-0.5 K in BTOrbit: Sun-synchronous, 1:30 PM sampling
S ath Width: 1650 km t ice dail s athSwath Width: 1650 km, twice daily swath
ConclusionsConclusionsConclusionsConclusionsRadiation plays a fundamental role as the Radiation plays a fundamental role as the source of energysource of energy
Spectral radiance provides detailed picture of Spectral radiance provides detailed picture of energy exchangeenergy exchange
Radiation as diagnostic of climate change Radiation as diagnostic of climate change ( t ti l)( t ti l)(potential)(potential)
ThanksThanksThanksThanksYung’s Group at CaltechYung’s Group at CaltechYung s Group at Caltech Yung s Group at Caltech Trenberth (NCAR)Trenberth (NCAR)Prof Xianglei Huang (U Michigan)Prof Xianglei Huang (U Michigan)Prof. Xianglei Huang (U Michigan)Prof. Xianglei Huang (U Michigan)
Ref: Goody and Yung (1989)Ref: Goody and Yung (1989)Huang and Yung (2005) JGR 110Huang and Yung (2005) JGR 110Huang and Yung (2005) JGR 110Huang and Yung (2005) JGR 110