A. Governing equations of the model   d. Radiation up previous next
A.d.i. Radiative transfer of atmospheric CO2

Both infrared and near infrared radiative fluxes associated with CO2 are calculated by using the Goody narrow band model (cf., Goody and Young, 1989). By using this band model, the temperature profile from 10 to 15 km, which is corresponds to the tropopause region of the dust-free Martian atmosphere, can be calculated precisely. In calculating the infrared radiative flux, only the CO2 15 μm band is taken into consideration. The upward and downward infrared radiative fluxes () and the infrared radiative heating rate per unit mass are calculated as follows.

(A.23)
(A.24)
(A.25)

is the i th narrow band width and is the Plank function which is represented as follows.

(A.26)

where is the Plank constant, is the speed of light, is the Boltzmann constant, is temperature. is the transmission function averaged over for .



is line strength, is the square root of the product of line strength and line width, is the reference value of , is effective path length, and is the reference pressure (1013 hPa).

When calculating the near infrared solar radiative flux, the CO2 4.3 μm, 2.7 μm, and 2.0 μm bands are considered. The near infrared solar radiative flux and the near infrared radiative heating rate per unit mass are calculated as follows.

(A.27)
(A.28)


where , is the solar zenith angle, is the solar radiative flux at the top of the atmosphere, which is represented as follows.

(A.29)
(A.30)


where is the surface temperature of the sun (5760 K), is the Stefan-Boltzmann constant (5.67×10-8 Wm-2K-4), is the solar constant at the mean radius of Mars' orbit (591 Wm-2), and are the radius of Mars' orbit and its mean value, is the solar radiative flux integrated over all wavelength at the top of the atmosphere. varies with season, latitude and local time. Detail descriptions of and are shown in Appendix A.d.vi.

The transmission function averaged over in the near infrared wavelength region is similar to that in the infrared wavelength region, except for the effective path length .



A Numerical Simulation of Thermal Convection in the Martian Lower Atmosphere with a Two-Dimensional Anelastic Model
Odaka, Nakajima, Ishiwatari, Hayashi,   Nagare Multimedia 2001
up previous next