Transcript Стратосферный циркумполярный вихрь как

The stratospheric polar vortex
as a cause for the temporal variability
of solar activity and galactic cosmic
ray effects
on the lower atmosphere circulation
S.Veretenenko, M.Ogurtsov
Ioffe Physical-Technical Institute, Russian Academy of
Sciences, St.Petersburg, Russia
23rd ECRS
GCR effects on troposphere pressure in different
epochs the large-scale atmospheric circulation
Epoch of increasing meridional circulation (C type) Epoch of decreasing meridional circulation (C type)
(1982-2000 гг.)
(1953-1981 гг.)

-0 .7
6
-0 .
0.4
-0.5
-0 .5
40
0.3
0.4
0
-20
0.3
0.4 0.6

0.4
-0
.4
-40
-0 .4
-0 .
4
-0
.4
-0.4
-0.2
-160-120 - 80 - 40
0
0.2
0.4
3
0.
.5
-0
-0 .5
-60
-80
-0 .4
Arctic front, January
Arctic front, July
Polar front, January
Polar front, July
Equatorial trough axis, January
Equatorial trough axis, July
-0.5
-0 .4
.5
-0
0.3
0 40 80 120 160
0.6
0.2
4
-0 . -0.4
-20
-40

-80
0.
4
0.4
0.4
20
0
-0 .5
0.4
-60
-0.6
0.4
80 -0 .6
60
0.5
20
-0 .4
Correlation coefficients between GPH 700 hPa and NM (Climax). Period: 1953-1981
-0
.4
0.6
.5
-0
0.7
-0 .5
4
-0 .
40
-0 .
5
60
0.
6
80
-0 .5
Correlation coefficients between GPH 700 hPa and NM (Climax). Period: 1982-2000
-160-120 - 80 - 40
0.5 5
0.
0.6
0 40 80 120 160
Arctic front, January
Arctic front, July
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
Polar front, January
Polar front, July
Equatorial trough axis, January
Equatorial trough axis, July
GCR increase in the minima of the 11-year cycle is accompanied


• Intensification of near-ground Arctic
anticyclones
• Intensification of extratropical cyclogenesis
at Polar fronts
• Weakening of the equatorial trough
(tropical cyclogenesis)
• Weakening of near-ground Arctic
anticyclones
•Weakening of extratropical cyclogenesis
•Intensification of the equatorial trough
Veretenenko and Ogurtsov, Adv. Space Res., 2012
Time variation of SA/GCR effects on troposphere pressure
and the evolution of the large-scale atmospheric
circulation
Veretenenko and Ogurtsov, Adv. Space Res., 2012
Time variations of the
correlation between
troposphere pressure at
high/middle latitudes and
sunspot numbers reveal a
pronounced ~60-year
periodicity.
160
(a)
120
160
80
W, days
100
E, days
C, days
200
80
W
E
C
120
0.8
1900
1920
1940
1960
1980
2000
(b)
0.4
0
-0.4
Polar Vortex
-0.8
1880
16
Spectral power density
Correlation coefficient
1880
40
1900
1920
Meridional form C
(c)
Reversals of the correlation
sign at high latitudes occurred
in the 1890s, the early 1920s,
1950s and the early 1980s
63 yrs
12
8
25 yrs
4
0
1940
Years
1960
1980
2000
0
0.04
0.08
0.12
0.16
16
0.2
Frequency, yr-1
The reversals of the sign of SA/GCR
effects coincide with the changes in the
evolution of the large-scale meridional
circulation (the form C according to
Vangengeim-Girs classification).
Spectral density
120
Polar region
64
12
85°N
80°N
75°N
8
36 23
4
0
0
0.04
0.08
0.12
Frequency, yr -1
0.16
0.2
The results obtained show:

Regional character of SA/GCR effects on troposphere
pressure which is determined by peculiarities of baric
systems forming in the regions under study;

SA/GCR effects may change the sign depending on the
time period;

The sign of SA/GCR effects seems to be determined by
the evolution of the large-scale meridional circulation;

There are long-term variations, with the period being ~60
years, of the amplitude and sign of SA/GCR effects on
troposphere pressure of high and middle latitudes
The aim of this work is to study
what processes may influence the evolution of
the circulation epochs and the sign of SA/GCR
effects on troposphere pressure?
Main elements of the large-scale circulation of
the atmosphere at middle and high latitudes
Troposphere
4
x 10
0
20
-160
160
0
20
-160
1.24
40
160
1.6
40
1.22
-120
60
120
1.4
-120
1.2
60
1.2
1.18
80
120
80
1
1.16
- 80
0.8
80
- 80
80
1.14
0.6
1.12


- 40
0.4

1.1
40


- 40
40
1.08
0
0.2

0
GPH 200 hPa. January 2005.
Magnitude of temperature gradients (grad/100 km). Layer 1000-500 hPa. January 2005.
Planetary frontal zone (areas of high
temperature contrasts in the troposphere )
Polar vortex (area of low pressure
In the upper troposphere)
Stratosphere
AIR TEMPERATURE. 20 hPa. January 2005.
-160
0
20
TEMPERATURE GRADIENT. 20 hPa. January 2005.
160
0
20
-160

160

40
-120
40
60
120
-120
60
80
120
80
1.3706
- 80
80
- 80
80
-79
- 40
40
- 40
40
0
-80
-75
-70
-65
-60
C
0
-55
-50
-45
-40
Polar vortex (cyclonic
circulation in the
middle/upper troposphere
and stratosphere at high
latitudes)
Planetary frontal zone
(regions of high
temperature contrasts in
the troposphere)
Extratropical cyclones and
anticyclones
-35
0.7
0.8
0.9
1
1.1
C/100 km
1.2
1.3
In the stratosphere the
polar vortex is seen as a
region of low
temperature with
enhanced temperature
gradients on its edges.
GCR effects on troposphere pressure
in the high-latitudinal area
Epoch of increasing meridional
circulation (1982-2000)
Correlation coefficients betw een GPH 700 hPa and NM (Clim ax). Period: 1982-2000
0
20
0.6
Epoch of decreasing meridional
circulation (1953-1981)
Correlation coefficients betw een GPH 700 hPa and NM (Clim ax). Period: 1953-1981
0
20
0.6
40
-0.3
-0.5
-0.4 60

0.4 40
0.3
0.4
0.4
-0.6
0.4
60
-0.5
0.2
-0.4
80
0.6
0
0.4
0.6
0.7
0.3
-0.5
-0.2
-0.6
-0.4
0.4
-0.5
0.2
0.3
0
-0.3
-0.2
0.2
-0.4
-0.7
-0.6
-0.5
-0.4
0.4
80
0.3
0.4
0.5
-0.3
-0.4
-0.6
-0.6
1
2
3
4
5
6
Confidence levels for R(GPH700,NM) according to Monte-Carlo tests.1982-2000.
0
20
-160
1
2
3
0
20
-160
60
120
0.97
0.95
-120
60
120
0.97
0.95 0.98
0.9
80
0.9
0.95
0.97
0.98
80
0.97
0.98
160
40
0.95
- 80
6
0.95 0.9
80
0.97
5
Confidence levels for R(GPH700,NM)according to Monte-Carlo tests. 1953-1981.
160
40
0.9
0.95
0.97
-120
4
0.99
- 80
0.9
0.95
0.97
0.98
80
0.9
0.95
0.9
- 40
40
0
- 40
40
0
In the high-latitudinal
area (independently of the
time period)
0.95
0.9
0.9
0.95
0.9
Most. statistically
significant correlation
coefficients between
troposphere pressure and
GCR are observed:
at Polar fronts (Polar
frontal zones) at middle
latitudes in the periods of
increasing meridional
circulation.
Correlation coefficients betw een GPH 700 hPa and NM (Clim ax). Period: 1982-2000
0
20
0.6
Correlation coefficients betw een GPH 700 hPa and NM (Clim ax). Period: 1953-1981
0
20
0.6
40
-0.3
-0.5
-0.4 60

0.4 40
0.3
0.4
0.4
-0.6
-0.5
0.2
-0.4
80
0
0.4
0.6
0.7
0.3
-0.5
-0.2
-0.6
-0.4
0.3
0
-0.2
0.2
-0.4
-0.7
-0.6
-0.5
-0.4
0.2
-0.3
0.4
-0.5
0.4
80
0.3
0.4
0.5
0.6
0.4
60
-0.3
-0.4
-0.6
-0.6
1
2
3
4
5
1
6
AIR TEMPERATURE. 20 hPa. January 2005.
-160
0
20
2
3
5
6
TEMPERATURE GRADIENT. 20 hPa. January 2005.
160
0
20
-160

160

40
-120
4
40
60
120
-120
60
80
120
80
1.3706
- 80
80
- 80
80
-79
- 40
40
- 40
40
0
-80
-75
-70
-65
-60
C
0
-55
-50
-45
-40
-35
0.7
0.8
0.9
1
1.1
1.2
The area of the polar
vortex formation is
an area of most
significant
correlations between
troposphere
pressure and GCR
variations
independently on the
time period and the
epoch of the largescale circulation
1.3
C/100 km
This suggests a possible contribution of processes taking place in the
polar vortex to GCR effects on the lower atmosphere circulation
~60-year cycle in the climate of the Arctic
and the polar vortex state
Gudkovich et al., Problems of Arctic and Antarctic, 2009
~60-year cycle in the Arctic climate
manifests itself as the rotation of cold
and warm epochs which is closely
related to the polar vortex states:
Strong vortex  warm epoch
Weak vortex  cold epoch
The transitions between warm and
cold epochs in the Arctic detected on
the base of sea-level temperatures
were found in the early 1920s, 1950s
and 1980s
Anomalies of mean yearly sea-level temperatures
at latitudes 70-85N in the Arctic.
The reversals of the sign of SA/GCR effects coincide well with the
transitions between cold and warm epochs in the Arctic
corresponding to the different states of the vortex.
Time evolution of SA/GCR effects on troposphere
pressure and the strength of the polar vortex according
to NCEP/NCAR reanalysis data
Correlation coefficient
0.8
a)
1950-1980 – the period of a weak vortex.
0.4
• Decrease of pressure gradients between middle and
high latitudes
• Increase of stratospheric temperature in the vortex area
• Weakening of the C form of meridional circulation.
• Cold epoch in the Arctic.
0
-0.4
R(SLP, Rz)
R(GPH700, NM)
-0.8
Frequency, days
120
110
b)
1980-2010 – the period of a strong vortex
100
• Increase of pressure gradients between middle and
high latitudes
• Decrease of stratospheric temperature in the vortex
area
• Intensification of the meridional circulation C.
• Warm epoch in the Arctic.
90
80
C
70
H, gp.m
30
20
500 hPa
c)
10
0
-10
H(40-65N)
-20
The sign reversals of SA/GCR effects
in the 1950s and 1980s correspond
to the transitions between the different
vortex states.
Polynomial fit
-30
Temperature, K
2
50 hPa
d)
1
0
-1
T (60-90N)
-2
1880
Polynomial fit
1900
1920
1940
Years
1960
1980
2000
Thus, the ~60-year variation of the amplitude and sign of SA/GCR
effects on troposphere pressure seems to be closely related to the
changes of the vortex strength and the corresponding changes of
the large-scale atmospheric circulation
Strong vortex :
GCR increase in the 11-year cycle  intensification of mid-latitudinal cyclones
and polar anticyclones
Weak vortex :
GCR increase in the 11-yr cycle  weakening of mid-latitudinal cyclones and
polar anticyclones
A possible reason for the sign reversals of SA/GCR effects may be
changes in the troposphere-stratosphere coupling caused by different
conditions for propagation of planetary waves in the periods of a
strong or weak vortex.
The polar vortex state seems to play an important part in
the mechanism of solar-atmospheric links
Temperature. 20 hPa. January 2005.
a)
-160
11
0
20
-35
160
40
-40
7
3
-120
2
60
-45
120
1
-50
0.5
80
-55
-60
0.5
- 80
-79
1
80
-65
2
3
- 40
-70
15
7
11
-75
40
-80

0
C
The polar vortex location and vertical geomagnetic
cutoff rigidities (in GV) according to Shea and Smart
(1983).
The area of the vortex formation is
characterized by low rigidities, so
GCR particles with a broad energy
range may precipitate here
including the low energy
component strongly modulated by
solar activity. Ion production rate in
the vortex area is higher compared
with that at middle and low
latitudes
Height, km
Pressure, hPa
b)
10
30
Temperature
Temperature gradient
Ion-pair production rate
20
25
30
20
50
70
100
15
150
200
10
300
400
500
5
700
850
1000
•The highest values of ionization due to GCR
are observed in the lower part of the vortex
(10-15 km) where temperature gradients at the
vortex edges start increasing.
• The 11-yr modulation of GCR fluxes is the
strongest at 20-25 km where the vortex is
most pronounced.
0
-90
0.4
0
-80
0.8
-70
-60
-50
Temperature, °Ñ
1.2
1.6
2
2.4
-40
2.8
-30
3.2
Temperature gradient, °Ñ/100 km
10
20
30
Ion-pair production rate, cm-3s-1
3.6
-20
Bazilevskaya et al., Space Sci. Rev, 2008
4
40
Height dependences of the Arctic air mass
characteristics in January 2005 and the
ion-pair production rate in free air at polar
latitudes (R = 0-0.6 GV) according to
Bazilevskaya et al. (2008).
Monthly averaged fluxes of ionizing particles
over Murmansk region (R =0.6 GV)
The vortex location is favorable for the mechanisms of solar
activity influence on the atmosphere circulation involving
variations of GCR intensity
Possible mechanisms of solar activity influence on the lower
atmosphere circulation may involve changes of the vortex
state associated with different agents (e.g., GCR variations,
UV fluxes)
Intensification of the polar vortex in the period when it is
strong seems to contribute to an increase of temperature
contrasts in tropospheric frontal zones and an intensification
of extratropical cyclogenesis
Conclusions:
 The evolution of the stratospheric polar vortex plays an important
part in the mechanism of solar-climatic links.
 The detected long-term oscillations of correlations between
troposphere pressure at middle and high latitudes and SA/GCR
characteristics seem to be closely related to the changes of the polar
vortex strength.
 The vortex strength reveals a roughly 60-year periodicity influencing
the large-scale atmospheric circulation and the sign of SA/GCR
effects on troposphere pressure.
 When the vortex is strong, meridional processes intensify and an
increase of GCR fluxes results in an enhancement of cyclonic
activity at middle latitudes and anticyclone formation at polar
latitudes. When the vortex is weak, meridional processes weaken
and GCR effects on the development of baric systems at middle and
high latitudes change the sign. A possible reason for the sign
reversals may be different troposphere-stratosphere coupling during
the periods of a strong and weak vortex.
