Coupled Ocean and Atmosphere Radiative Transfer (COART)

This is a tool for you to calculate radiance and irradiance (flux) at any levels in the atmosphere and ocean Specify the inputs simply by clicking the buttons and changing the default numbers in the table. Setting Ocean_depth=0 reduces it to conventional atmospheric radiative transfer model. More information here.

Select calculation type and Output levels:

Spectral fluxes (irradiances) (up and down) (W/m2/um) at a single wavelength (um)
Spectral fluxes(w/m2/um) at multiple wavelengths from um to um at every um.
Integrated fluxes (W/m2) from to um in Spectral resolution of um.
Broadband shortwave (0.20-4.0um) fluxes (W/m2). (Takes about 30 seconds)
Radiances (W/m2/um/Sr) at wavelength (um).
Radiances (W/m2/um/Sr) at multiple wavelengths from um to um at every um.
Radiance(w/m2/um/Sr) in band: to um in Spectral Resolution of um;
                                             OR in satellite channel: (Need few minutes)
? Want to include the Water-leaving radiance output ? yes no
Radiance output angles: at Zenith(deg) or at every (deg) from to
Azimuth(deg) or at every (deg) from to
**See how the angles are defined here.

Output at: TOA, Surface, km above surface, and (m) below surface; OR All levels in atmosphere.

Solar Zenith Angle Calculation or Input

JulianDay: GMT(hour): Latitude(deg N): Longitude(deg E):
Ignore time and location, at a directly inputed Solar Zenith Angle (deg):
At multiple Solar Zenith Angles (deg): from to in step of
*Note: Method 1 calculates Earth-Sun distance, Methods 2 and 3 use mean Earth-sun distance.

For thermal radiation (>4um), input Surface temperature:


Select an atmospheric model
If checked, use less atmospheric layers to save computation time ( not recommended for UV and IR).
If checked, input your total integrated precipitable water (g/cm2):
If checked, input your integrated ozone amount (atm-cm): (1 atm-cm=1000 Dobson)
You can also change these trace gas amounts by a factor (1.0 for no change) of --> CO2: CH4:

Select Mixed layer aerosol: & Stratospheric aerosol:
Select a method to specify aerosol loading (To be ignored if "No aerosol" selected above):
by Visibility (km): by AOT at 0.5um: by AOT at 0.55um:
If checked, input aerosol optical properties in the table below (not required to fill all elements, undefined numbers will be fit in by the selected model above):
g :
If checked, upload aerosol phase function file:

Select Cloud: Bottom(km): Top(km):; size RE(um):
LWP(g/m2): or OpticalDepth(0.6um): (RE is effective size for nonspheric)


Wind speed(m/s): Depth (m): Bottom albedo: Chl (mg/m3):(Chlorophyll)
Particle scattering coefficient (m-1):   bp(lamda)= b0(550/lamda)nx[Chl]k;   Input b0: , n: and k:
Particle scattering phase function If use F-F func., input bb/b:
If checked, input absorption a(m-1): (Override the default parameterization)
If checked, input your a440DOM(m-1): (DOM absorption coefficient at 440nm)
If checked, ignore surface roughness and assume Flat ocean surface.

*Note: Input Depth=0 will ignore the ocean and ocean inputs above (no water, same as atmosphere-land case).

. . . . Not clear on some input? Read "The Input" section Here.
For comments/questions contact Zhonghai Jin, but to read this NOTE first may help you.