AE 1601 – Standard Atmosphere Activity Turn in on Canvas (Individual) Background Information The purpose of this exercise is to gain an understanding of planetary atmospheres by comparing the atmospheres of Venus and Mars to the Earth standard atmosphere. Atmosphere profiles for Venus and Mars will be constructed based upon published data obtained by space flight entry probe observations. There are several handy equations and constants used in this exercise. They are listed below.
a.
Relation between geometric altitude (
h
G
), geopotential altitude (
h
), and planet radius (
r
0
) ℎ
=
𝑟𝑟
0
𝑟𝑟
0
+
ℎ
𝐺𝐺
ℎ
𝐺𝐺
b.
Hydrostatic Equation for Isothermal Layer, or constant temperature (note in lecture p=p
2
, p
b
=p
1
) 𝑝𝑝
2
=
𝑝𝑝
1
𝑒𝑒
−
[
𝑔𝑔
0
/(
𝑅𝑅𝑅𝑅
)](
ℎ
2
−ℎ
1
)
c.
Hydrostatic Equation for Gradient Layer, or variable temperature (note in lecture T=T
2
, T
b
=T
1
) 𝑝𝑝
2
=
𝑝𝑝
1
�
𝑇𝑇
2
𝑇𝑇
1
�
−𝑔𝑔
0
/(
𝑎𝑎𝑅𝑅
)
Note: a
is the temperature lapse rate with altitude. d.
Equation of State (Ideal Gas Law) 𝑝𝑝
=
𝜌𝜌𝜌𝜌𝑇𝑇
e.
Specific Gas Constants (R): Earth = 287 J/(kg K), Mars = 188.92 J/(kg K), Venus = 188.92 J/(kg K) f.
Planet Radii: Earth = 6,378.14 km, Mars = 3,397.2 km, Venus = 6,051.8 km g.
Gravitational Acceleration at Planet Surface: Earth = 9.8 m/s
2
, Mars = 3.8 m/s
2
, Venus = 8.9 m/s
2
