A review of interesting atmospheric phenomenon observed on extraterrestrial planets, specifically, Venus and Jupiter. We close with a brief look at the Dark Snow project, studying the deposition of soot on green land glacial ice and the effects it has on melt

1. Extraterrestrial Atmospheres
A Brief Overview

2. So far -
● Atmospheric composition
● Vertical profile of Temperature and Pressure
● Albedo, Weather, and Climate change
○ on Earth
● Venus & Jupiter

3. Venus fact sheet
● Distance from Sun - 0.7 AU
● Mean density ratio - 0.951
● Surface gravity ratio - 0.905
● Bond albedo* ratio - 2.94 (0.90/0.306)
● Solar irradiance ratio - 1.911
● Orbital period - 224 days
● Rotational period - 243 days
Reference : Fact sheet, Lunar & Planetary Science, NASA

4. Venus fact sheet
● Surface pressure - 92 bars
● Avg. Temperature - 737 K (surface)
● Wind speeds
○ - 0.3 to 1.0 m/s on surface
○ 90 m/s on the upper layers of the atmosphere
■ 113 m/s in tropical cyclone on earth
■ 135 m/s in tornadoes
● Atmospheric composition (by vol)
○ 96.5% CO2
, 3.5% N2
○ 150 SO2
, 70 Ar, 20 H2
O, 17 CO, 12 He, 7 Ne

5. Atmospheric transmission of Venus
Transmission spectrum of Venus as a transiting exoplanet
Ehrenreich et al. 2011, Astronomy & Astrophysics Journal
● Theoretical model with inputs from Venus Express.
● Rayleigh scattering from CO2
at 70 km
● Mie scattering from H2
SO4
droplets at 70-90 km

6. atmospheric transmission - earth

9. winds
Venus Express mission has helped distinguish between
● Acoustic Waves
● Inertia-gravity waves
● Lamb waves
● Surface waves
○ similar to those in the geostrophic regime
● Centrifugal waves
○ special case of Rossby waves, arising from
cyclostrophic balance
Peralta et al. 2014 (I) and Peralta et al. 2014 (II)

10. Superrotation
In order to explain superrotation on Venus -
● Yamamoto & Takahashi 2006, maintained by meridional
circulation.
● Durand-Manterola 2010, driven by trans-terminator flow

11. Jupiter fact sheet
● Mass of Jupiter - 0.09% M_sun
● Solar irradiance ratio - 0.037
● Blackbody temperature - 110.0 K
● bond albedo ratio - 1.12
● Atmospheric composition (by vol) -
○ 89.8% H2
, 10.2 % He
○ 3000 CH4
, 260 NH3
, 28 HD, 5.8 C2
H6
, 4 H2
O
● Surface pressure >> 1000 bars
● wind speeds
○ ~ 150 m/s at < 30 latitude
○ ~ 40 m/s at > 30 latitude

12. Jupiter’s bands

13. Jupiter’s giant red spot

15. Jupiter’s giant red spot
On Earth
● typical cyclone speeds
○ ~100 m/s
● typical size of a cyclone
○ ~100-2000 km
Jupiter’s giant red spot
● speed near the edge
○ ~120 m/s
● size of the cyclone
○ 20,000 km by 12,000 km

16. the spot is shrinking, albeit very slowly.
Hassanzadeh & Marcus 2013 studied the
unexpected longevity of the giant red spot and
attributed meridional circulation as the cause.
● can extract shear energy and energize the
vortex

17. Similar to a previous method, to estimate the atmospheric
transmission of Venus by observing it during transit,
Tsumura, Arimatsu, Egami et al. 2014 observed the Jovian
moons eclipsed in the Jovian shadow.

18. back to earth
● Climate change and how global warming raises the
mean sea level
● Methane or carbon trapped in polar or glacial ice
● Soot and how it changes the albedo of Earth
○ what happens to all of this soot?

19. Dark Snow project