Study Guide (lecture # 15)
Book pages: 161-177, 238-240
Review:
(lecture # 14)
- baroclinic and barotropic conversions;
- energy box diagrams;
- summary of zonal average energy
Today's topics:
- zonal variations observed in: Radiation, T, V:
- Sections: 5.1, 5.2, 5.3, 6.2.3.1,
Jargon:
jet entrance and jet exit regions
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Non Zonal Fields:
(Chapter 5, start)
- General purposes: emphasize geographic variations and review
- Organize interpretation around these regions that keep being mentioned:
- near the east coasts of continents (land/sea contrast)
- near subtropical west coasts (land/sea contrast) (includes deserts)
- tropical land masses (land/sea contrast)
- major mountainous areas
- along midlatitude frontal cyclone tracks (differs from 1. in S. Hemisphere)
- Radiation (chapter 5.1)
- albedo (clouds, desert & ice); much cloudiness areas: 2, 3, 5
- absorption; (highest in equatorial regions with fewer clouds)
- emission: relates to surface T of emitter: cloud tops (if thick, not thin cirrus) or surface
- high clouds are cold, so small emission
- region 2 has high albedo and high emission
- net radiation: >0 in tropics, <0 at high latitudes with these exceptions:
- <0 over deserts & persistent stratus decks (region 2)
- Temperature (chapter 5.2)
- at surface, zonal variations mainly from: land/sea contrasts; and elevation
- at upper levels:
- In SH contours quite zonal, less seasonal change.
- In NH time mean long wave pattern; (troughs near region 1)
- heat flux down gradient of T (meridional & zonal directions)
- recall: proportional to AZ to AE conversion (cyclone development)
- magnitude larger on east side of longwave troughs (east side of region 1)
- Velocity (chapter 5.3 and 6.2.3.1)
- at low levels: relate Hadley cell motion to subtropical highs
- ICZ location between subtropical high in SH and NH
- ICZ little seasonal shift in east Pacific, otherwise preference for region 3
- at upper levels: subtropical jet maxima near region 1 (associate with thermal wind)
- time mean: balance between u u x and va in jet entrance & jet exit regions (see 6.2.3.1)
- jet axis further poleward on downstream end;
- jet max location near 120E in NH & SH (will be shown later to have similar forcing)
- Tropical easterly jet (Arabian Sea)