Jim Angell’s contributions toJim Angell’s contributions tounderstanding the QBOunderstanding the QBO

Jim Angell’s contributions toJim Angell’s contributions tounderstanding the QBOunderstanding the QBO

Jim Angell’s contributions toJim Angell’s contributions tounderstanding the QBOunderstanding the QBO

QBO !

discovery of QBO

discovery of QBO

Angell andKorshover1962, 1963

Meridional structure of QBOMeridional structure of QBO from Angell and Korshover, 1963 from Angell and Korshover, 1963

Equatorial QBO derived fromEquatorial QBO derived from radiosondes and rockets radiosondes and rockets

Baldwin et al., 2001

Schematic of global QBO

Baldwin et al., 2001

Angell andKorshover (1964) coin the term‘Quasi-BiennialOscillation’

Naming the QBO was not Naming the QBO was not easy...easy...

kind-of biennial oscillationalmost biennial oscillationnot quite biennial oscillationsomewhat biennial oscillationquasi-biennial oscillation

50 hPatemps

noteout-of-phase

betweentropics and

midlats

QBO temperature signal in lower QBO temperature signal in lower stratospherestratosphere

derived from regression with MSU4derived from regression with MSU4

Snapshot of temperatures and meridional Snapshot of temperatures and meridional circulationcirculation

associated with the QBOassociated with the QBO

note extensioninto winter midlats

February1994

out-of-phasevertical structure

Equatorial waves

and the QBO

powerspectra

tropics

subtropics

midlats

strong peak at 10-15 days

Idealized wave-mean flow interaction in QBO

Kelvin waves only propagatein background easterly winds

zonal wind

eddypower spectra

Kelvin waves observed during easterly QBO winds

QBO effects on ‘centers of action’

Surface signal of QBOSurface signal of QBO

Baldwin et al., 2001

Holton-Tan effect

observations1964-1996

SKYHIsimulation(48 years)

Holton-Tan effect (composited QBO E-W)

Meridional structure of QBOMeridional structure of QBO from Angell and Korshover, 1963 from Angell and Korshover, 1963

evidence ofHolton-Tan

effect

Ozone QBO

out of phasebetween tropicsand midlats

totalinterannualvariability

QBOcomponent

Column ozone from TOMS

Vertical structure of ozone QBO at equator

2-cellstructure

QBO signal in nitrogen dioxide (NO2)

QBO andstratosphericwater vapor

stratosphericwater vapor

tropical tropopausetemperature

QBO variations in stratospheric water QBO variations in stratospheric water vapor from HALOE satellite data, 1991-vapor from HALOE satellite data, 1991-20032003

Deseasonalizedanomalies

Vertical propagation of QBO Vertical propagation of QBO anomaliesanomalies (interannual ‘tape recorder’) (interannual ‘tape recorder’)

HALOE H2Oanomalies

tropicaltropopausetemperatureanomalies

Stratospheric H2O anomalies are consistent with tropical tropopause temperature changes

Jim Angell’s contributions span all aspects of the QBO.

* global structure and propagation* ozone* equatorial waves* coupling with troposphere* tropopause and stratospheric H2O

Much of this original research is still relevant today!

Happy Birthday Jim!

QBO