Oxygen: Stratosphere, Mesosphere and Thermosphere Part-3 Chemical Rate Equations Ozone Density vs. Altitude Stratospheric Heating Thermal Conductivity Thermospheric Structure Temperature Structure on other planets

Rate Equations for Oxygen Chemistry

Introduce Ozone

Ozone continued

Dependence on z Remember: J2(z) = J2o exp[ -2(z)/] where  = cos 2(z) = abs o n2 dz n2(z)  0.21 nM nM(z) = nM(0) exp(-z/H) in mixed region J3(z) = J3o exp[ -3(z)/] For 3(z) need n3(z) which we are solving for.

T High z J2/J3 =constant ~10-7 Low z J2/J3 --> 0 J2 80 J3 40 10-2/s mesopause 80 n3 … stratopause Tropopaus 20 T n3 , T

Densities of O2,O3 and O C+H High z n1  1/n21/2 n3  n23/2 Log10n(mol/cc) To get right: need some diffusive separation in the upper regions At night: J2(z) and J3(z) --> 0 ‘slow’ reactions become important

Temperature vs. Altitude Earth’s Atmosphere Stratospheric Heating peak and Ozone Peak related J3(z) = J3o exp[ -3(z)/] dT/dt  h3 J3(z) n3(z)

Summary

Thermosphere + Ionosphere Z 130km 80km EUV I R Thermal conduction mesopause

Fs(z) Dz FT + DF z FT

Thermosphere Continued

Thermosphere T Structure Tm is where the heat conducted downward is radiated to space Relation to our old Te?

Thermosphere Structure (Cont)

Integral for thermosphere model y(x) = ox { [1-exp(-x’)]/x’} dx’ x  (z); y  T7/4

Temperature vs. Altitude Earth’s Atmosphere Rise in T in Thermosphere due to EUV Absorption and Thermal Conduction to Mesopause These are averages Tropopause is higher and hotter Near equator ~16-18km and ~ 10km near poles Drives high altitude horizontal flow Jets ~10km to be close to stratosphere and avoid turbulence

A result of Horizontal Transport Ozone column density in ppm Tropopause higher near equator and lower in T Drives upper atmospheric flows Will treat horizontal transport soon

Noctilucent Clouds (night shining clouds, ~85km, ice grains) (polar mesospheric clouds) over a lake in northern Sweden Possibly produced by climate change and space shuttle exhaust Polar Stratospheric (nacreous)Clouds ~15-25km: ice, nitric and sulfuric acids Implicated in ozone holes

Polar Stratospheric (nacreous)Clouds ~15-25km: ice, nitric and sulfuric acids Implicated in ozone holes

Thermosphere T depends on Solar Activity Earth’s Thermal Structure dePL Thermosphere T depends on Solar Activity

CO2 even at high altitudes --> cooling Slow Rotation Venus Atmosphere dePL Cloud Tops --> Te CO2 even at high altitudes --> cooling Slow Rotation 1 year = 2 days (retrograde due to thickatmosphere and tidal forces?)

Dust absorbs h and changes the lapse rate Mars Atmosphere dePL Te at Surface Dust absorbs h and changes the lapse rate Thermosphere strongly dependent on solar activity

Photo-chemistry Venus + Mars CO2 + hn ® CO + O (1) CO+O+M ® CO2 + M (2) (2) is very slow at Mars (density of M Is very small): Expect considerable CO, especially so as free O oxidize surface (iron oxide) But there is a small amount of H2O H2O + hn ® OH + H (3) CO + OH ® CO2 + H (4) On Venus CO --> CO2 may be aided by sulfur + chlorine species

Titan’s Atmosphere dePL Stratosphere/ mesosphere due to absorption in hydrocarbon haze CH4 + h -> CH3 +H(CHf +H2) React to form CnHmand H2 escapes. Thermosphere subject to particles from Saturn’s magnetosphere

Adiabatic lapse rate down to liquid metal hydrogen Giant Planets dePL Internal heat sources Adiabatic lapse rate down to liquid metal hydrogen Jupiter has evidence of a stratosphere and a mesosphere

Atmosphere Thermal Structure: Summary Typically troposphere (Lower, Convective) Mesosphere [ Stratosphere ] (Middle, Radiative) Thermosphere (Upper, Conductive) Exosphere (Escape) Venus Temperature Lapse, g £ Gd Tropopause at cloud layer (~ 70 km) Te ~ Top of cloud layer Thermosphere (Cryosphere) Td ~ 300 km (CO2 at high altitudes) Tn ~ 100 km (Slow rotation 1yr » 2 days) Mars Temperature Lapse g £ Gd (Strong Day / Night Variations: Dust g << Gd Mesosphere T < Te (CO2 cooling) Thermosphere like Mesosphere (Strongly affect by solar activity) Titan Temperature Lapse g ~ Gd Stratosphere (Haze Layer) Mesosphere (Cooler to space) Thermosphere (Solar UV + Energetic Particles from Magnetosphere Cooled by HCN, Slow Rotations) Grant Planets Internal heat source comparable to solar Tropopause ~ 0.1 bar, g ~ Gd, Temperature + pressure increase to about 2M bar so phase change to a liquid (metallic) state (4x104 km) and a metallic core (3x104 K) (1x104 km) (Jupiter) Mesosphere (stratosphere) £ 0.001 bar Hydrocarbon coolants Thermosphere (Solar EUV)

Earth’s thermal structure Rate equations Oxygen reactions Ozone layer #3 Summary   Things you should know Earth’s thermal structure Rate equations Oxygen reactions Ozone layer Stratosphere Mesosphere Thermosphere Thermal conductivity Heat flux