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Study Guide (lecture #4)

Book pages: 52-63, (In Sect. 6.1: 221-227, skim the rest)

#### Review:

(lecture #3)
- "glass slab" (energy balance) model formulas & solutions

- iterative (energy balance) model w/ sfc heat fluxes

- radiation by latitude

#### Today's topics:

- meridional heat transport

- zonal average T distribution

- radiative balance model of vertical T structure

#### Jargon:

scale height, diabatic, troposphere, stratosphere,
tropopause, optical depth, net radiative transfer,
skin temperature, radiative equilibrium, lapse rate

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#### Heat transport

(fig. 3.9)
(from imbalance of absorption & emission)
(types)
latent heat flux:
- Hadley cells lower level motion
- scale height for water vapor much less than for dry air

#### Zonal average
Temperature ([T]):

- "[ ]" means zonal average -- see Appendix

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#### Radiative balance models

- - obtains a vertical structure of T field by specifying
absorber present & incoming radiation
- -Method/assumptions:
- - local radiative balance for each layer, T independent of time
- - absorber present (fig 6.2) incorporated into optical depth
- - absorbed radiation dI must be emitted for energy balance
e*dtau*sec(phi)
- - use method of moments to replace irradiance dI/dtau term with
easier handled dF/dtau radiance term.
- - everything cast in terms of IR emission.

- - first examine F independent of tau (implies no solar
absorption, convection, or heat fluxes)
- - have 4 main "problems" compared to observations:
- - heat fluxes are observed, so:
- model is valid at 38 N or 38 S on annual
average
- or must add fluxes to model, making dF/dtau nonzero

- - superadiabatic lapse rates
- - T discontinuity @ top but especially @ bottom
- - lapse rate always >0, but that not observed in upper stratosphere

- "fixes" for these problems to be examined next lecture