Lectrue No.	: Stratosphere


1.  Temperature
    (1)	Lower stratosphere
  	A.  Poles:	300 mb (10km).
	B.  Tropics:	100 mb (15 km).
	C.  Air temperature is lower over equator (tropics).
    (2)	Middle stratosphere 
	A.  20-30 km.
	B.  Higher temperature over equator.
    (3)	Upper stratosphere
	3-1 mb or 50 km.
    (4)	Semiannual oscillation in maximum temperature
	A.  Equator
	    (A)	Maximum temperature at equinoxes.
	    (B)	Maximum temperature at 40 km.
	B.  Poles
	    (A)	Maximum temperature at solstices.
	    (B)	Maximum temperature at 30 km.
2.  Zonal Wind
    (1)	Summer
   	A.  Easterlies.
	B.  Warm poles and cold equator.
	    24 hours daylight over poles.
    (2)	winter
	A.  Westerlies.
	B.  Cold poles and warm equator.
3.  Maximum zonal winds at the equator
    (1)	Westerlies
	30 m/s at equinoxes at 50 km.
    (2)	Easterlies at summer solstice.
4.  Quasi-Biennial (26 month) oscillation
    (1)	Maximum zonal wind speed of 20 m/s at 25 to 30 km over the
	tropics.
    (2)	Bands of mean wasterly and westerly zonal components descendng in
	succession in the stratosphere at a rate of 1 km/month.
    (3)	Causes
	A.  Transference of momentum from eastward propogating Kelvin
	    waves.
	B.  Transference of momentum from westward propagating mixed
	    Rossby-gravity waves of very long wave length propagating
	    upward from the troposphere in tropical easterlies.