Circulation in the atmosphere
•	Local winds/breezes
–	Land/sea
–	Mountain/valley
•	Mountains act as elevated heat sources, can lead to T-storms in mtns.
–	Chinook 
–	Katabatic 
•	Cold air drainage off ice sheet, highland 

•	Non-rotating earth?
•	Not that easy, more like this…
–	Equatorial low
•	Straddles Equator, area of many storms and much rain
–	Why? Hot air rises convectively from much insolation
–	Subtropical high
•	Descending, warm air
–	Trade winds
•	NE in N hemis.; reliable

•	So, we have completed one ‘cell’
–	Where are the rainforests?
–	Where are the worlds deserts?
•	Westerlies
–	~ 30o – 60o N/S latitude; USA
–	Jet stream
•	Strongest in winter
–	Why? Greatest temp differences
•	Cold in north; warm in south
–	Produce steep gradients aloft, where there is only PG and Coriolis involved

•	Sub-polar low, ~ 60o 
•	Polar Easterlies, 60o – 90o 

•	Intertropical convergence zone (ITCZ)
–	Area of low pressure at Equator
•	Subtropical high (Bermuda, Pacific, etc)
•	Subpolar low (Aleutian low, Icelandic low)
•	Polar high

•	Monsoons
–	Seasonal reversal of winds
•	Asia
–	So lots of rain in summer, none in winter
•	USA/Mexico

•	El Nino
–	Weakened Trade winds, ‘sloshing’ back of warm waters
•	Southwest? 
–	El Nino = wet
–	La Nina = dry

Humid east coast/dry west in N hemisphere