Atmosphere and Ocean. Three Choices for Radiation. Outline. Atmospheric RadiationTransfer: And Sun Photometers. Madhu Gyawali and Pat Arnott

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Atmopheric RadiationTranfer: And Sun Photometer Madhu Gyawali and

Outline Solar and Terretrial Spectrum Modification of olar

Earth Atmophere Energy balance Interaction with ga molecule and

Atmophere and Ocean Three Choice for Radiation Infrared Emiivity

Source can be viible or infrared radiation, or other wavelength a

What miing? Climate conequence of thee choice. (from www.ldeo.

../olar_radiation) Earth Surface Temperature Spectrum of Solar

& t = 0, T e = 303K (Greenhoue Max) t =1, T e = 255 K (No

2, T e = 289 K (Jut Right) T e T R R e a t Earth radiative

1 Atmopheric RadiationTranfer: And Sun Photometer Madhu Gyawali and Pat Arnott ATMS 360 Atmopheric Intrumentation Univ NV Reno Outline Solar and Terretrial Spectrum Modification of olar radiation reaching to the earth urface Radiation tranfer in the Earth Atmophere Energy balance Interaction with ga molecule and Aerool Sun Photometer Meaurement of Aerool Optical Depth Atmophere and Ocean Three Choice for Radiation Infrared Emiivity i the ame a aborptivity. Source can be viible or infrared radiation, or other wavelength a well. From: What miing? Climate conequence of thee choice. (from Earth Surface Temperature Spectrum of Solar Radiation Flux 1/4 " T e =T R 2 % $ (1a) ' $ R 2 ' $ e 2(1+t) ' # & t = 0, T e = 303K (Greenhoue Max) t =1, T e = 255 K (No Atmophere) t = 0.2, T e = 289 K (Jut Right) T e T R R e a t Earth radiative temperature Sun radiative temperature Sun radiu Sun to Earth ditance Earth urface olar reflectance IR tranmittance of Earth atmophere. The un emit 41% of it radiation in the viible pectrum, 9% in the ultraviolet pectrum 50% in the near infrared pectrum

2 Spectral View of the Earth Radiation Balance from Space TOP OF THE ATMOSPHERE TOP OF THE ATMOSPHERE AND AT THE SURFACE Effect of Rayleigh (ga) cattering, O 2 and N 2. Effect of Rayleigh (ga) cattering, O 2 and N 2, And effect of extinction by aerool particle. Effect of gaeou aborption.

Earth Light: Spectrum of Outgoing Infrared Radiation Infrared Spectrum from the

2 From Cunningham & Cunningham, 2004,.1. 3.5 1 1.5 2 2.

Nitrogen(N2) Concentration % or ppm 78.084% ---- Oxygen(O2) 20.94% ---- Argon(Ar).

3 Earth Light: Spectrum of Outgoing Infrared Radiation Infrared Spectrum from the Atmophere to the Surface CO 2 O 3 H 2 0 From CH 4 Spectrum of Solar Radiation Flux Global Energy Balance O 3 O 2 H 2 O H 2 O,CO 2 From Cunningham & Cunningham, 2004, "( µ m) Incoming = = 133 Outgoing = = 133 From Cunningham & Cunningham, 2004, Fig. 9.2 Major Atmopheric Window Compoition of the atmophere at ground level Ga Reidence Time Nitrogen(N2) Concentration % or ppm % ---- Oxygen(O2) 20.94% ---- Argon(Ar).934% --- Water(H2O).4 to day Carbon dioxide(co2) 370 ppm 4 year Ozone(O3) ppbv Day-week Methane(CH4) 1.75 ppm 10 year Helium(He) 5.24 ppm 2. 10^6 Krypton(Kr) 1.14 ppm --- Hydrogen(H2).4 to Xenon(Xe).087 ppm --- baed on Junge, 1963; Andrew et al)

What are Aerool? Definition; Aerool are tiny particle upended in air, either in olid phae or liquid phae or both.

001µm(molecular cluter) to 100 µm(mall rain drop) Aerool Source Primary and Secondary Sulfate, Soot Primary particle introduced directly into the atmophere (e.g.

gato-particle converion) Natural and Anthropogenic Aerool Natural dominate in rural (remote) area Anthropogenic dominate in urban area 10µm 2.

dut 4-10000 30 Foret fire 3-150 20 Ga-to-particle converion 100-260 180 Photochemical 40-200 60 Total for natural ource 2200-24000 3100 ANTHROPOGENIC Direct emiion 50-160 120 Ga-to-particle converion

4 What are Aerool? Definition; Aerool are tiny particle upended in air, either in olid phae or liquid phae or both. Concentration; The highet concentration are uually found in urban area, reaching up to 10 8 and 10 9 particle per cc (Seinfeld and Pandi, 1998). Size; Aerool range in ize from around.001µm(molecular cluter) to 100 µm(mall rain drop) Aerool Source Primary and Secondary Sulfate, Soot Primary particle introduced directly into the atmophere (e.g. moke from combution) Secondary particle formed by chemical reaction in the atmophere (e.g. gato-particle converion) Natural and Anthropogenic Aerool Natural dominate in rural (remote) area Anthropogenic dominate in urban area 10µm 2.5µm Human Hair(65 µm diameter) Source; Thermo electron corporation Bioma Burning Sea Salt Source of Atmopheric Aerool Soil dut Sea alt Botanical debri Volcanic dut Foret fire Ga-to-particle converion Photochemical Total for natural ource ANTHROPOGENIC Direct emiion Ga-to-particle converion Photochemical Total for anthropogenic ource Amount, Tg/yr [10 6 metric ton/yr] Effect Of Aerool Direct effect Scattering and aborption of radiation Indirect effect Role in cloud micro phyic Clean cloud Large cloud droplet Low albedo Efficient precipitation Polluted cloud Small Cloud droplet High albedo Suppreed precipitation (Data from: W.C. Hind, Aerool Technology, 2nd Edition, Wiley Intercience) Aerool Optical Propertie Optical thickne;τ(λ) τ(λ)= z 2 z1 " e ( z) dz where e (z) i the extinction coefficient and i the um ( ) of cattering and aborption coefficient + a It i the indirect meaure of the ize and number of particle preent in a given column of air. Aerool Optical Propertie Single cattering albedo; " 0 () Scattering coefficient( ) " 0 () = Extinction coefficient( + ) The magnitude of ingle cattering albedo largely depend on the complex part of refractive index, and particle ize. a Phae function ;P(Θ,λ) It decribe the angular dependence of light cattering. It determine the ign(cooling/heating, depending on the planetary albedo) of the aerool radiative effect. Cooling when the value i larger than about 0.85, and warming when it i below thi value.

$Optical Propertie of Small Particle µ= n + ik µ = complex index of refraction n = cattering (real part) k = aborption (imaginary part) The real part of the index of refraction i only a weak function$ 55 0 Black Carbon (oot) 1.96 0.66 Mineral dut ~1.53 ~0.

55 0 Black Carbon (oot) 1.96 0.66 Mineral dut ~1.53 ~0.

5 Optical Propertie of Small Particle µ= n + ik µ = complex index of refraction n = cattering (real part) k = aborption (imaginary part) The real part of the index of refraction i only a weak function of wavelength, while the imaginary part, ik, depend trongly on wavelength. Refractive indice of aerool particle at λ = 589 nm Water Ice NaCl H 2 SO SiO Black Carbon (oot) Mineral dut ~1.53 ~0.006 (einfield,et al) Seinfeld & Pandi, Atmopheric Chemitry and Phyic, Scattering; (Redirection of radiation out of the original direction) Rayleigh Scattering: Scattering from mall particle(comparion to the wavelength). Mot effective for horter wavelength, 1 " # 4 Scattering from atmopheric gae are well undertood ince major gae (nitrogen and oxygen) that comprie 99% of the atmophere are well mixed Particle cattering; It occur motly in the lower portion of the atmophere where larger particle are more abundant, and dominate when cloud condition are overcat Nonelective cattering occur when the particle are much larger than the wavelength of the radiation. The effect due to aerool cattering are quite variable due to wide range of aerool concentration and to the variety of aerool found in the atmophere. Rayleigh and Particle Scattering Aerool Radiative Effect Regional Haze, Air Quality and Viibility (COHA, FAQS) Photochemical Reaction (Atlanta Superite) Photoynthei and Crop Yield (ChinaMAP) Climate Change - Whitehoue Effect (ACE-Aia, ChinaMAP) Directly - Scattering & Aborption of Solar Radiation Particle ize parameter 2"R x = Indirectly - Modifying Cloud Propertie

Scattering and Aborption of Light by Aerool Scattering Model of an Aerool Layer Fraction reflected upward $ r = (1 $ e # )" Fraction aborbed= (1 $ )(1 $ e ) Io=Light Source (W/m 2 ) L=Path Length I "

$downward tranmitted fraction t= e + (1 $ " )(1 $ e ) Total reflected off urface= % t ( % = urface albedo ) 2 F 0 = incident olar flux (wm -2 ) 2 t # F = " F (1 ) [( ) ] A c = fraction of the urface$

6 Scattering and Aborption of Light by Aerool Scattering Model of an Aerool Layer Fraction reflected upward $ r = (1 $ e # )" Fraction aborbed= (1 $ )(1 $ e ) Io=Light Source (W/m 2 ) L=Path Length I " L "( p + ap + eg L ext ) I 0 = e = e I=Light Detector (W/m 2 ) $ = (" + " )* L; # = " /(" + " ); ( b, g) p ap p p ap Fraction tranmitted= e Fraction cattered downward = (1 $ " )(1 $ e ) Total downward tranmitted fraction t= e + (1 $ " )(1 $ e ) Total reflected off urface= % t ( % = urface albedo ) 2 F 0 = incident olar flux (wm -2 ) 2 t # F = " F (1 ) [( ) ] A c = fraction of the urface covered by cloud 0 " Ac Ta r + " 1" r T a = fractional tranmittance of the atmophere Aerool Scattering and Aborption Coefficient Dp,max $ p( ") = # ( Dp, ", ri) m( Dp ) ddp cat Dp,min Dp,max $ ap( ") = # ( Dp, ", ri) m( Dp ) ddp Where: ab Dp,min λ = Wavelength (m) D p = Particle Diameter (m) α cat, α ab = Ma Scattering and Aborption Efficiencie (m 2 /g) ri = Refractive Index m(d p ) = Aerool Ma Size Ditribution Major Aerool Chemical Specie that Contribute to the Light Extinction Sulfate Aerool SO 2 from Foil Fuel Combution Carbonaceou Aerool Organic Compound (OC) Bioma Burning, Automobile Emiion, Foil Fuel Combution, Ga-to-particle Converion of Hydrocarbon Elemental Carbon (EC) (Aborption, Warming Effect) Incomplete Combution of Foil and Bioma Fuel Mineral Dut Aerool Deert Dut, Contruction, Road Dut Nitrate Aerool Indutrial and Automobile Emiion Note: Aerool Extinction Depend on Wavelength (Ångtrom Exponent, å = - d log σ ext / d log λ ), Chemical Compoition, and Size Viibility Impairment of Aerool Baed on Aerool Chemical Speciation Data: IMPROVE Equation GOES View of the Dut Streak Acro North America, April 17 B ext = 3 * f(rh)* {[Ammonium Sulfate] + [Ammonium Nitrate]} + 4*1.4*[OC] + 10*[LAC] + 1*[Soil] + 0.6*[CM]+ 10 (Rayleigh Ga Scattering) [Sulfate] i the ulfate concentration, for example. [OMC]=organic matter, [LAC]=light aborbing carbon [CM]=coure ma. f(rh)=hygrocopic growth factor. Viual Range (V.R.) = K/B ext Where K i the Kochmieder Coefficient the log of the contrat threhold of the human eye, K = GOES10 view of dut treak on the morning of April 17 GOES8 view of dut treak on the evening of April 17 29

Tranport of the Aian dut to the United State Origin of the

with the upper low preure trough / cut-ff low and urface low

northeat China and north Korea [Kim et al., 2002].

zonal wind ditribution due to the jet treak [Kim et al.

30 Strong low preure ytem itting in northeat Mongolia caued

condition, dut can be lifted from the dry urface of the Aian

Technique: Beer Law Light from the Sun caue the LED detector

Thi current goe to the operational amplifier, o that the LED

Thi ignal i then meaured by an attached digital voltmeter.

com Reult: TOD from Langley plot method Beer Law A

7 Tranport of the Aian dut to the United State Origin of the Aian Dut The common weather condition are uually aociated with the upper low preure trough / cut-ff low and urface low preure ytem (low formed by a trong cyclonic vortex) over northeat China and north Korea [Kim et al., 2002]. Under thi weather condition, Aian dut can move fat along the zonal wind ditribution due to the jet treak [Kim et al., 2002]. 30 Strong low preure ytem itting in northeat Mongolia caued urface wind peed to be a high a ~30 m/ Given uitable weather condition, dut can be lifted from the dry urface of the Aian Gobi deert region and tranported to the United State in about 7-10 day. Optical Depth Meaurement Intrument: Sun Photometer, Technique: Beer Law Light from the Sun caue the LED detector to generate a tiny electrical current. Thi current goe to the operational amplifier, o that the LED current i tranformed into a voltage ignal. Thi ignal i then meaured by an attached digital voltmeter. Source : Reult: TOD from Langley plot method Beer Law A connection between radiation at the top of the atmophere ( E0 ) and on the urface (E ) E ( ) = E0 ( ) exp[#" ( )m] i, 1 = co m Ln( E0 ) Top of the atmophere Ln( E ) = Ln( E0 ) # m" ( ) Ln(E ) " ( ) m Ln(V-Vd) Langley plot method: calibration air ma (m) 34

Meaurement from Sun Photometer and Spectrometer Angtrom

59 $ ( AOD) = "#% very large particle very mall particle

interaction(cattering a well a aborption)of olar

the nature of particle, ize of particle, a well a the

The Sun Photometer offer an inexpenive a well a

8 Meaurement from Sun Photometer and Spectrometer Angtrom Coefficient: " 0 " 4 = 1.59 $ ( AOD) = "#% very large particle very mall particle (Rayleigh regime) Ln( ) Ln( ) Concluion: The interaction(cattering a well a aborption)of olar radiation by atmopheric contituent i trongly dependent on the nature of particle, ize of particle, a well a the wavelength of radiation. The Sun Photometer offer an inexpenive a well a convenient way of meauring aerool optical depth. By knowing the aerool optical depth we can etimate the ize of upended particle. THANK YOU FOR YOUR ATTENTION

Blackbody radiation. Main radiation laws. Sun as an energy source. Solar spectrum and solar constant.

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