Earth’s atmosphere - atmdyn.orgatmdyn.org/teaching/intro_dyn1/01_introduction.pdfEarth’s...
Transcript of Earth’s atmosphere - atmdyn.orgatmdyn.org/teaching/intro_dyn1/01_introduction.pdfEarth’s...
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Earth’s atmosphere
Things we understand, so far (we think…)
1. Composition
2. Structure
3. motions or phenomena
Earth
The Atmosphere
• Very thin layer compared to the earth’s radius (a = ~6400 km)
(from Meteorology today)
Atmosphere
Convection
Pressure (as a function of altitude)
(from Meteorology today)
• Pressure decrease exponentially with increasing altitude
Meridional structure (temperature)
(from ERA40 Atlas)
Troposphere (~0-10 km)
Stratosphere (~10-50 km)
16 km
32 km
48 km
Warm
Cold
We live here
Meridional structure (temperature)
(from ERA40 Atlas)
Troposphere (~0-10 km)
Stratosphere (~10-50 km)
16 km
32 km
48 km
Warm
Cold
We live here
Will be covered in another course
Meridional structure (zonal wind)
(from ERA40 Atlas)
Troposphere (~0-10 km)
Stratosphere (~10-50 km)
16 km
32 km
48 km
westerly (jet)
westerly (jet)
We live here
easterly
Meridional structure (zonal wind)
(from ERA40 Atlas)
Troposphere (~0-10 km)
Stratosphere (~10-50 km)
16 km
32 km
48 km
westerly (jet)
westerly (jet)
We live here
easterly Will be covered in another course
Meridional structure (meridional wind)
(from ERA40 Atlas)
Troposphere (~0-10 km)
Stratosphere (~10-50 km)
16 km
32 km
48 km
We live here
• http://www.geography.hunter.cuny.edu/tbw/wc.notes/7.circ.atm/animations/GlobalWind.html
Global circulation
Rossby wave
(from Atmosphere, Weather and Climate)
High%PV%
Low%PV%
(,)%.ve%PV%anomaly%% %=>%an.cyclonic%circ.%%
(+)%.ve%PV%anomaly%%%=>%cyclonic%circ.%%
Wave%propaga.on%
Newly%displaced%parcels%%by%induced%circula.on%
Rossby wave (energy propagation)
Pacific/North American Pattern (PNA) (from CPC, NOAA)
Source
Source
Stationary waves (mid-latitudes)
(from ERA40 Atlas)
• Effects of topography and land-sea contrast(N. Hemisphere)
Stationary waves (mid-latitudes)
• Effects of topography and land-sea contrast(N. Hemisphere)
(from ERA40 Atlas)
Gill-type response (tropics)
(Dima and Wallace, 2007)
(Gill, 1980)
From basic equations set
Simplify and solve