Influences of the 11-year sunspot cycle on the stratosphere and the importance of the QBO

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1 (Solar Variability, Earth s Climate and the Space Environment; Bozeman, Montana, June 2008) Influences of the 11-year sunspot cycle on the stratosphere and the importance of the QBO Karin Labitzke, Institute for Meteorology, F.U. Berlin Germany (Labitzke and van Loon, numerous papers, ) 1

2 The topics of my lecture today are: 1) Variability of the Arctic Winters -- the Sun and the QBO 2) Solar Signals in Summer 2

3 : trend = K/dec; sigma = 9.2K (after 2001 = ECMWF) 3

4 n = Hm = 2250,1 dm sigma = 45,2dm trend = dm/dec sign. 12 %

5 February red = warm event ~ El Nino P blue = cold event SO A CH solar min solar max no correlation with 11 year solar cycle r = 0.22 (n = 67) Tropical volcanoes W: Agung March 1963 E: Chichon March 1982 E: Pinatubo June

6 SO Cold event Warm event cold and strong (Labitzke and warm and weak van Loon, 1987) QBO SUN AO Westphase Eastphase Solar min Solar max High index (+) Low index (-) cold and strong (Holton and Tan, 1980; warm and weak , n = 18) like QBO cold and strong (Labitzke + van Loon, opposite to QBO ) (Baldwin and warm and weak, Dunkerton, 2001) Different forcings influencing the stratospheric polar vortex during the northern winters 6

7 The Quasi - Biennial Oscillation ( ) QBO-definition: 40+50hPa in Jan+Feb)/4 7

8 FU-Berlin QBO east phase QBO west phase n = 13 r = Correlations between 30-hPa Heights and the Solar Flux , 29 years = 3cycles; Labitzke (1987) n = 16 r =

9 EAST Correlations between 30-hPa Heights and the solar cycle WEST max = % max = % February , NCEP/NCAR, n = 59 years 9

10 Detrended Temperature, February, NCEP/NCAR, Correlations Temperature Differences (max min) 200 ~95% (shading = corr. > +/- 0.4) > 99 % n = 59 years ~ 6 solar cycles 10

11 strongest MMWs in east min + 5 coldest winters in west min 90S 90N Deviations of the zonal mean temperatures (K) in (Jan+Feb)/2 from the long-term mean (1968 through 2002); (shading larger than 1 (2) standard deviations) -8 nodal point lines: ~ 30S and ~ 55N in both cases 11

12 Teleconnections, i.e. Correlations between the Arctic and the Tropics ALL Winters

13 Teleconnections QBO Solar Cycle (in the middle stratosphere/ upper troposphere) Solar MIN QBO West, northern winter: weakening of BDC (Holton + Tan) Equator N. Pole COLD vortex Solar MIN QBO East, northern winter: intensification of BDC (Holton + Tan) Equator N. Pole 13

14 Teleconnections QBO Solar Cycle (in the middle stratosphere/ upper troposphere) Solar MAX QBO West, northern winter: intensification of BDC Equator N. Pole Solar MIN QBO West, northern winter: weakening of BDC (Holton + Tan) Equator N. Pole COLD vortex Solar MAX QBO East, northern winter: some weakening of BDC Equator N. Pole Solar MIN QBO East, northern winter: intensification of BDC (Holton + Tan) Equator N. Pole 14

15 July, Northern Summer, the dynamically least disturbed season 15

16 all; rmax = 0.69 east; rmax = 0.93 o west; rmax=0.64 Correlations between the solar flux and the detrended 30-hPa 16 temperatures in July ( ); red = corr. > 0.4; blue is temp. diff. > 1K

17 near Nagasaki ( , n = 40) all r = 0.57 east r = 0.84 west r =

18 ALL: correlations Temperature Diff. solar max - min Zonal mean temperatures in July, (NCEP/NCAR): left: correlations with 10.7cm solar flux; right: temperature differences (K) between solar max and solar min. 18

19 July, : Detrended Temperature Correlations (NCEP/NCAR) East: n = 18 r max = 0.86 > 99 % km West: n = 20 r max = 0.57 (4 solar cycles) N 19 (Labitzke 2003, updated)

20 East n = 18 Temperature Differences, (solar max min) July, tropical warming = downwelling = weakening of Brewer-Dobson C. 3 West n = 20 Intensification of Hadley Circulation? More convection over equator? (-) + 20

21 Temperature Differences, (solar max min) standardized: July, , n = 40 QBO/east QBO/west - 21

22 30-hPa Heights, solar max solar min, bi-monthly through the year I 22

23 30-hPa heights, solar max solar min, (Jul + Aug)/2 anomalous wind from the west in solar max, i.e. weaker QBO/East in solar max anomalous wind from the east in solar max, again weaker QBO/West in solar max 23

24 The Constructed Annual Mean l of the differences between solar max and solar min for the 30-hPa temperature and for the 30-hPa height, separately for the QBO east and west phases ( ) east l east -- 30N (QBO/east is weaker in max) 80 24

25 The Constructed Annual Mean Differences, (solar max - solar min), separately for QBO east and west Temperature differences (K) 10 Height differences (m) E N + (-) + + W 25

26 Weaker QBO in Solar Max solar min: (H+T) QBO east is stronger QBO west is stronger and and polar vortex is polar vortex is warmer/weaker stronger/ colder But: solar max: QBO east and west are weaker in max and the condition of the polar vortex is opposite to solar min ( and to H+T) 26

27 Thank you for your attention 27

28 WELCOME TO BERLIN: STP-12 Symposium 12 th -16 th July, 2010 (SCOSTEP/ First Announcement; 28

29 North Pole February 30 hpa Heights, NCEP/NCAR + Rec. r = years later and 16 years back; filled symbols = MMWs; n = solar cycles; WE in red, CE in blue; van Loon and Labitzke (1994), updated) 29

30 !! r = 0.84, Tdiff = 2.1 K r = 0.39, Tdiff = 0.8 K (sigma = 1K) 30 (near Nagasaki) (Chichon = March 82/ east; Pinatubo = June 91/east )

31 Scatter diagrams of the zonal wind (m/s) over the equator at (40+50 hpa)/2 in July (absolute values) against the 10.7 cm solar flux. Period: (n = 55, r = 0.07, Data set Fu-Berlin) Left: years in the east phase of the QBO (n = 25). Right: west phase The QBO is weaker in solar max and stronger in solar min! 31

32 FEB Standard Deviations for February and July JUL Temp Height Labitzke and Kunze, 2008) 32

33 July: correlations T (max-min) standardized all east west ( ) 33