Recent work on the N
2 Lyman-Birge-Hopfield (LBH) b
and (α
1Π
g-
X1Σ
g+) emissions from the Earth's
aurora and daytime
airglow has shown that models can give good agreement with observations by including cascading between the singlet (α1Π
g,
w1Δ
u and α′
lΣ
u−) states. Both radiative
and collision induced transitions contribute to the cascading. The collision induced transitions involve a process - sometimes referred to as collision-induced electronic transitions (CIET) - which has not been included in most models of the LBH b
ands from the Earth's atmosphere. Cascading not only improves the fit to the relative vibrational populations observed, it also increases the emission from the LBH b
ands, by a factor of
1.6 in the daytime
airglow. Such an increase is consistent with recent work by Budzien
et al. [1994]
and Link
et al. [1994]. In the
aurora some calculations have included radiative cascading but not CIET, which is expected to be more important in typical
auroras. However, the calculations involving CIET are based on extrapolation from laboratory measurements. These extrapolations are a source of significant uncertainty in the calculations.