Planetary-Scale Mountain Waves Planetary-scale waves are observed that remain fixed with respect to the earth’s surface: Possible causes are geographic distribution of: –Mountains (Charney and Eliassen 1949) –Land/sea differences and inequitable distribution of sensible and latent heating (Smagorinsky 1953) After 30 years of debate, answer settled that both are important, but mountains perhaps a little more so

500 mb Height

Sea Level Pressure

Gross-simplification of planetary-scale stationary waves Himalayas/ Tibetan Plateau Rockies Upper- tropospheric flow Kuroshio Gulf Stream

Ertel’s Potential Vorticity P = (  + f ) /  p Potential vorticity conserved for adiabatic, large-scale motion Mountain pp pp E

Conservation of Potential Vorticity Mountain P = (  + f ) /  p  anticyclonic; clockwise  cyclonic; counterclockwise  

700 mb Height (Stone 2001)

700 mb Vorticity (Stone 2001)

Held

Manabe and Terpstra (1974) Observed

Manabe and Terpstra (1974) With Mountains Observed

Manabe and Terpstra (1974) Without Mountains Observed

200 mb Height (Stone 2001)