### Dependence on temperature and pressure

The values of some spectral line parameters depend on environmental temperature and pressure. The database contains the values of these parameters at ** T_{ref}** and

**of corresponding**

*P*_{ref}*data source*.

#### Temperature dependence of the line intensity

To calculate the intensity*of*

**S**^{j}*spectral line at temperatures different from the reference temperature of the*

**jth***data source*, one uses the following expression

*, (1)*

**S**^{j}(T) = S^{j}(T_{ref}) · rQ · rB · rEwhere

*is the intensity of the line*

**S(T**_{ref})*at*

**j***is the ratio of total internal partition functions at*

**T**_{ref}*,*_{ }**rQ****and**

*T*_{ref}*(2)*

**T**

rQ = Q(TrQ = Q(T

_{ref})/Q(T) .The values of the partition functions

*for isotopologues presented in HITRAN are calculated by Fortran program, TIPS.for in the temperature interval from 70 to 3000 K. The values of the partition functions*

**Q(T)***for isotopologues not presented in HITRAN are provided by authors of corresponding linelists.*

**Q(T)***accounts for the ratio of Boltzmann populations*

**rB***(3)*

**rB = exp(−c**_{2}·E^{j}_{l}/T)/exp(−c_{2}·E^{j}_{l}/T_{ref}) .*accounts the effect of stimulated emission*

**rE***(4)*

**rE = (1 - exp(-c**_{2}·WN^{j}/T))/(1- exp(-c_{2}·WN^{j}/T_{ref})) .In expessins (3) and (4)

*is the lower-state energy of*

**E**^{j}_{l}^{ }*line,*

**jth***is the wavennumber of*

**WN**^{j }*line,*

**jth***is the second radiation constant.*

**c**_{2}

Temperature and pressure dependence of the line width

The half-width at half maximum (HWHM) of spectral lineis used on simulation of spectrum functions for building of profile of spectral line (see Line profiles).

The

*of the line*

**Doppler half-width***is independent of the pressure and calculated by the expression following from expression (2) in previous paragraph*

**j***. (5)*

**D**^{j}(T) = D^{j}(T_{ref})·sqrt(T/T_{ref})The

*Lorentz half-width*of the line

*at temperature*

**j***, pressure*

**T***and partial pressure*

**P***is calculated as*

**P**_{self}*(6)*

**L**^{j}(T,P) = (T_{ref}/T)^{Njt}· (L^{j}_{env}(T_{ref},P_{ref}) · (P - P_{self}) + L^{j}_{self}· P_{self}) ,where

*-temperature-dependence exponent defined above.*

**N**^{j}_{t}

Temperature and pressure dependence of the line position

The air pressure leads to a shift of the line position. This shift is given by expression*, (7)*

**WN**^{j}(P) = WN^{j}+ P^{j}_{shift}· P/P_{ref}where

*is the wavenumber of the line*

**WN**^{j }*,*

**j***is the pressure shift of the line*

**P**^{j}_{shift}*at*

**j***.*

**P**_{ref}The pressure shift should also include a temperature dependence, but that effect is not considered now.