[89] | 1 | ;+ |
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| 2 | ;- |
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| 3 | ;---------------------------------------------- |
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[97] | 4 | function lwdown_clark, sst,qair,cld,tair,ps |
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[89] | 5 | ; |
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| 6 | ; Net longwave from the Clark et al. (1974) bulk formula |
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[97] | 7 | ; Clark, N. E., L. Eber, R. M. Laurs, J. A. Renner, and J. F. T. Saur, |
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[89] | 8 | ; 1974: Heat exchange between ocean and atmosphere in the |
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| 9 | ; eastern North Pacific for 1961-71. NOAA Tech. Rep. NMRS |
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| 10 | ; SSRF-682, National Oceanic and Atmospheric Administration, |
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| 11 | ; U.S. Department of Commerce, Washington, DC, 108 pp. |
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| 12 | ; See also Gill, p34. |
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| 13 | ; |
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| 14 | ; INPUTS |
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| 15 | ; sst : Sea surface temperature (degC) |
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| 16 | ; qair: specific humidity (g/kg) |
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| 17 | ; cld : cloud cover |
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| 18 | ; tair: surface air temperature (degC) |
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| 19 | ; ps : surface pressure (mb) |
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| 20 | ; OUTPUT |
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| 21 | ; lw : estimated longwave (W/m2) |
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| 22 | ; |
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| 23 | @common |
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| 24 | ;---------------------------------------------- |
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[97] | 25 | ; |
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[89] | 26 | eps=.97 ; emissivity of sea-water |
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| 27 | sig=5.67e-8 ; Stefan-Boltzman constant (W/m2/K4) |
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| 28 | Ts=(sst+273.15) ; SST in K |
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| 29 | Ta=(tair+273.15) ; Tair in K |
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| 30 | q=qair/1000. ; specific humidity (kg/kg) |
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| 31 | r=q/(1-q) ; Mixing ratio |
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| 32 | ea=ps*r/(r+.62197) ; Specific humidity into vapor pressure |
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[97] | 33 | ; |
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[89] | 34 | lw= eps*sig*Ts^4*(.39-.05*ea^.5)*(1.-.51*cld^2) $ |
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[97] | 35 | +4.*eps*sig*Ts^3*(Ts-Ta) |
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| 36 | ; |
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[89] | 37 | lwup=eps*sig*Ts^4 |
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[97] | 38 | ; |
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[89] | 39 | lwdown=lwup-lw |
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[97] | 40 | ; |
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[89] | 41 | return, lwdown |
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[97] | 42 | ; |
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[89] | 43 | end |
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