Effects of the 11-Year Sunspot
Cycle on the Earth‘s Atmosphere
Karin Labitzke
Institute for Meteorology, F.U. Berlin
Germany
( Labitzke and van Loon, numerous papers,
1987 – 2006)
1
INTRODUCTION
The understanding of natural and
anthropogenic climate change is an
important issue today.
Here, the influence of the 11-year
sunspot cycle as a natural
variability factor on the
atmosphere will be discussed.
2
Topics of the lecture are:
1) Variability of the Arctic Winters
-- the Sun and the QBO
2) Influence of the Arctic Winters
on the Tropics and Subtropics
3) Solar signals in Summer
3
Polar Stratospheric
Clouds (PSCs)
Ozone Layer
The LAYERS of the EARTH‘s ATMOSPHERE
(Labitzke and van Loon, 1999)
4
1
2
1948 – 2006
3
4
5
n = 59
sigma = 8.5 K
trend =
+ 0.9 K / dec
sign. 84 %
3
GWATT, #2
5
G
2
4
5
1
1
2
3
4
1942 - 2006
5
n = 65
Hm = 2249,8 dm
sigma = 458 m
trend =
+ 1.9 m/dec
sign. 5 %
5
4
3
1942 – 2006:
11 > +1 sigma
12 < - 1 sigma
x
1942 – 1973:
6 > + 1 sigma
66< - 1 sigma
1
2
SO
Cold event
Warm event
QBO Westphase
Eastphase
SUN Solar min
Solar max
AO
7
cold and strong
warm and weak
cold and strong
warm and weak
like QBO
(Labitzke and
van Loon, 1987)
(Holton and Tan, 1980;
1963-1978, n = 18)
(Labitzke + van Loon,
opposite to QBO
High index (+) cold and strong
Low index (-) warm and weak
1987 – 2006)
(Thomson and
Baldwin, 2001)
Different forcings influencing the stratospheric
polar vortex during the northern winters
red = warm event - SO
blue = cold event - SO
all: n = 59
r = 0.19
P
Ch
CH
A
A
8
P
no correlation
with 11-year
solar cycle
Tropical volcanoes
Agung 1963
Chichon 1982
Pinatubo 1991
Quasi-Biennial Oscillation
QBO
Time- height section of monthly
mean zonal winds (m/s) at
equatorial stations:
Canton Island (3°S / 172°W)
(Jan 1953 – Aug 1967);
Gan/Maledive Islands (1°S
/73°E)
(Sep 1967 – Dec 1975);
Singapore (1°N /104°E)
(since Jan 1976).
Isopleths are at 10 m/s intervals,
westerlies are shaded ;
(updated from Naujokat 1986).
(grey = west; white = east)
(50 + 40hPa in Jan + Feb)/4
9
Sunspot number since 850 AD
Courtesy of Solanki et al., 2006
10
11
Courtesy Dr. Claus Fröhlich, Space Science Rev., 2000
12
Percentage UV Radiation Differences
between Solar Maxima and Minima
Solar Maxima:
more UV radiation
5-8 %
Wellenlänge (nm)
Data from Lean et al. (1997)
13
Percentage Ozone Variability between Solar
Maxima and Minima
Annual Mean
+3 %
Solar Maxima:
more UV radiation
=> more ozone
+3 %
Data from 2-D Model (Haigh, 1994)
14
all years (n = 59) :
no correlation with
the solar cycle:
r = 0.19
15
FU-Berlin
QBO east phase
QBO west phase
1958 - 1986
n = 16
n = 13
r = - 0.7
16
r = 0.78
Correlations between 30-hPa Heights and the Solar Flux
1. 1958-1986 (29y, 3 cy), Labitzke (1987)
1958 - 2006
n = 22
r = - 0.4
n = 27
r = 0.68
> 95 %n
Correlations between 30-hPa Heights and the Solar Flux
17
2. 1958-2006 (49 y) (5 cycles), ( 20 more years, in blue)
REC
QBO east
QBO west
1942 – 2006
47
42
43
n = 29
r = -0.3
r = 0.7
n = 36
> 99 %
Correlations between 30-hPa Heights and the Solar Flux
3) 16 years back: 1948 – 1957 (10 y, red); 1942 –1947 (6 y, orange, REC )
18
(Labitzke et al., 2006)
30-hPa Heights
February
(~ 22 – 24 km)
East
r max = 0.61
n = 26
95%
Correlations
Height Differences (gpm)
solar max – solar min
- 400m
+640m
West
r max = 0.68
n = 33
99%
(Labitzke et al., 2006)
19
February 1948 – 2006, NCEP/NCAR, n = 59 years
EAST
max = 0.61
WEST
95%
max = 0.68
99%
February 1948 – 2006, NCEP/NCAR, n = 59 years
20
WEST
EAST
- 400 m
+ 640 m
30-hPa heights, differences between solar max and min
21
January 2006
Deviations of
30-hPa temps.
from a longterm mean;
(1968-2002)
blue = negative,
red = positive
anomalies,
> 2 sigma
(east / min =
intensification
22 of BDC)
-
-5
-
-5
January 2006
Deviations of 30-hPa temps. from a long- term mean;
blue = negative, red = positive anomalies, > 2 sigma
23(eastphase
is colder than mean, therefore anomalies smaller over equator
Deviations of temperatures from a long- term mean:
(1968-2002)
blue =
negative
orange =
positive
anomalies,
red =
> 2 sigma
24
February
+ UV  + Δ T
40
Solar MAX
QBO WEST:
50
40
30
(-)
20
20
10
00
Major Warmings are
connected with
km
down
welling and
warming over the
Arctic,
i.e. intensification
of the Brewer-Dobson
Circulation,
with up welling and
cooling to the
south
(same for min/east)
25
10.7 cm solar flux (Jan+Feb) / 2 and
Occurrence of Major Midwinter Warmings 1942 - 2006
x
150
110
= MMW in Westphase: 10 in max, 0 in min !!
= MMW in Eastphase: 3 in max, 10 in min
26
(Labitzke et al., 2006)
max >150
min < 110
X = omitted
Major Midwinter Warmings in Jan/Feb connected with
Warm Events (WE) or Blocking (1942 – 2006)
SOLAR Minimum (<110 s.f.) | SOLAR Maximum (>150 s.f.)
Warm Event
Blocking
Warm Event
Blocking/ Atlantic
02/03 J (middle)
69/70 J
57/58 F
90/91 F
88/89 F (CE)
80/81 F
78/79 F (CE)
67/68 J (CE)
59/60 F
48/49 F
46/47 F
W
E
S
T
E
A
S
T
27
86/87 J + F
76/77 J
72/73 F
65/66 F
51/52 F
41/42 F
05/06 J + F
03/04 J
84/85 J
62/63 F
00/01 F
70/71 J
56/57 F
10.7 cm solar flux (Jan+Feb) / 2 ,
Occurrence of Major Midwinter Warmings
and Cold Polar Vortices, 1942 - 2006
C
x
C
C
C
C
150
110
C
= MMW in Westphase: 10 in max, 0 in min !!
= MMW in Eastphase: 3 in max, 10 in min
28
(Labitzke et al., 2006)
(
= cold winter)
max >150
min < 110
X = omitted
CH
P
A
E
E
E
E E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E = QBO eastphase
29
E
E
E
E
TELECONNECTIONS
In the period 1942 – 2006 (n = 65)
26 MMWs (in Jan/Feb) : 40% of all
28 cold winters
: 43% of all
(N. Pole: Jan/Feb: < -75 / < -70)
= 83% of all Arctic winters
determined the teleconnections between
the Arctic
and the Tropics and Subtropics.
30
Conclusion for the Winter
The magnitude of the solar signal is
analyzed on the time - scale of 11 years.
To find the solar signal, it is necessary to
introduce the different phases of the QBO.
Emphasis is put on the Major Midwinter
Warmings (MMWs), i.e. an intensification of
the Brewer Dobson Circulation,
and on the Cold Winters in the Stratosphere
over the Arctic, (i.e., a weakening of the
BDC) and it is shown that their influence
reaches well into the Summer (Southern)
Hemisphere.
31
• We suggest that the effect of the solar
variability influences the diabatic meridional
circulation over the tropics and subtropics,
namely the Hadley Circulation in the
troposphere and the Brewer-Dobson
Circulation in the stratosphere.
• 83% of the Arctic winters determine the
teleconnection between the Arctic and the
Tropics and Subtropics through MMWs and
Cold Vortices, respectively.
32
July, Northern Summer,
the dynamically least disturbed season
33
Extra for Japan
all
r=
0.7
temp. diff.
max - min
max
east
r = 0.89
max
west
r = 0.61
x
max
sigma/30N=
0.8 K
34
shaded red : r > 0.5
shaded blue: t-diff > 1 K
east
west
r = 0.85, Tdiff = 2.2 K
35
(near Nagasaki)
r = 0.39, Tdiff = 0.8 K
(Chichon = March 82/ east; Pinatubo = June 91/east )
near Nagasaki
(1968 – 2006, n = 39)
all
r = 0.57
Ch
east
r = 0.85
west
r = 0.39
36
July, 1968 – 2005: Detrended Temperature
Correlations (NCEP/NCAR)
East: n = 18
r max = 0.86
> 99 %
10
32 km
West: n = 20
r max = 0.57
200
90N
(4 solar cycles)
37
(Labitzke 2003, updated)
Temperature Differences, July, 1968 - 2005
East
n = 18
tropical warming
= downwelling
3
= weakening of
Brewer-Dobson C.
West
n = 20
(-)
Intensification of
Hadley Circulation?
More convection
over equator?
38
+
JULY
Solar Max
QBO EAST
Tropical warming
km
+ UV  + Δ T
indicates downwelling,
i.e.
40 weakening of BDC
50
40
this leads to a
colder
20
polar vortex in
the winter hemisphere
10
30
20
(-)
00
39
0
(same with solar
min/west, this
leads to very cold
polar winters)
Summary for the Summer Part
Japan is a very suitable region
to study the solar signal
during the summer season.
40
41
Thank you for your attention
42
(1942 – 2006)
43
significance > 99%
Late Winter Cooling
T/min: -- 77°C
17 March 2006: 10-hPa map
44
March 2006
Deviations of
30-hPa Temps.
from a longterm mean;
blue = negative,
red = positive
anomalies,
> 2 sigma
45
Tropical warming,
= downwelling,
= weakening of BDC
this leads to a
colder polar vortex
March 2006
Deviations of 30-hPa Temps. from a long- term mean;
blue = negative, red = positive anomalies, > 2 sigma
46
Why is the Variability of the
Arctic Stratosphere in Winter
so important?
Karin Labitzke
Institute for Meteorology, F.U. Berlin
Germany
47
( Labitzke and van Loon, numerous papers,
1987 – 2006)
References
Labitzke, K., 1987: Sunspots, the QBO, and the stratospheric temperatures in the north
polar region. Geophys. Res. Lett., 14, 535-537.
Labitzke, K. and H. van Loon, 1988: Associations between the 11-year solar cycle, the
QBO and the atmosphere. Part I: The troposphere and stratosphere in the northern
hemisphere winter. J. Atmos. Terr. Physics, 50, 197-206.
van Loon, H. and K. Labitzke, 1994: The 10-12 year atmospheric oscillation. Review
article. Meteor. Z., 3, 259-266.
Labitzke, K., and H. van Loon, 1999: The Stratosphere: Phenomena, History, and
Relevance. Springer, Berlin, Heidelberg, New York, 179 pp.
van Loon, H. and K. Labitzke, 2000: The influence of the 11-year solar cycle on the
stratosphere below 30 km: A review. Space Sci.Rev.,94, 259-278.
Labitzke, K., 2003: The global signal of the 11-year sunspot cycle in the atmosphere:
When do we need the QBO? Meteor. Z., 12, 209-216.
Labitzke, K., 2005: On the solar cycle-QBO relationship: a summary. J. Atmos. Sol.Terr.Phys., 67, 45-54.
van Loon, H., G.A.Meehl, J.M.Arblaster, 2004: A decadal solar effect in the tropics in
July – August. J. Atmos. Sol.-Terr. Phys., 66, 1767- 1778.
Labitzke, K., M. Kunze and S. Brönnimann, 2006: Sunspots, the QBO, and the
stratosphere in the north polar region – 20 years later. Meteor. Z., 15, 355-363.
48
49
Holton, 1995, J. G. R.