Possible traces of solar
activity effect on the surface
air temperature of midlatitudes
A. Kilcika, A. Özgüçb, J. P. Rozelotc
aDepartment of Physics, Faculty of Science, Akdeniz University, 07058 Antalya, Turkey
bKandilli Observatory and E.R.I., Bogazici University, Cengelkoy, 34684 Istanbul, Turkey
cUniversité de Nice Sophia Antipolis- Observatoire de la Côte d'Azur CERGA,
Av. Copernic, 06130 GRASSE, France
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Goals
To understand the existence of solar activity effects on
the surface air temperature of mid-latitudes.
To find the correlation between the surface air
temperature of mid-latitudes and solar flare index, if
any.
To find the periodicities of the air temperature of midlatitudes related with the solar activity.
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Studied area on Earth
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DATA
Monthly surface air temperature data of mid latitudes and
monthly solar flare index data sets are used as climate
parameter and solar activity indicator, respectively.
Temperature data set of Turkey is taken from Turkish
State Meteorological Service. The temperature and
altitude data sets out of Turkey are taken from web-site
of North Eurasia Climate Centre, (NEACC)
http://neacc.meteoinfo.ru. Volcanic activity data is taken
from Earth System Research Laboratory web page
http://www.esrl.noaa.gov/gmd/about/climate.html
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What is Flare Index?
The quantitative flare index is FI = i·t, where i represents the
intensity scale of importance of a flare in Hα and t the duration
in Hα (in minutes) of the flare. The daily sums of the index for
the total surface are divided by the total time of observation of
that day. Because the time coverage of flare observations is not
always complete during a day, it is corrected by dividing by the
total time of observations of that day to place the daily sum of
the flare index on a common 24-hour period.
Calculated values are available for general use in anonymous ftp
servers of our observatory and NGDC.
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Values of i Used for the Determination of FI
Importance
SF, SN, SB
1F, 1N
1B
2F, 2N
2B
3F, 3N, 4F
3B, 4N
4B
i
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SOLAR_FLARES/INDEX/
http://www.koeri.boun.edu.tr/astronomy/23cyc.html
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The data set covers 25 - 50 degree longitude interval
including Turkey and Europian part of Russia
We limited the altitude with 428 meters. The main
selection criterion of the stations is the monthly data
continuity for the investigated time periods.
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To obtain latitude dependencies of sun climate
relation all the temperature data are divided four
latitudinal intervals.
Latitudinal
Intervals
36 – 42 (Turkey)
Number of
Stations
23
40 – 50
5
50 – 60
15
60 – 70
4
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FI and the mean surface temperature
according to the latitudes
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30º – 40º
Correlation coefficients
50º - 60º
60º - 70º
40º - 50º
-0.09284
0.12364
-0.17344
0.12881
0.22086
0.34993
0.18595
0.12770
0.60899
0.04499 Full data
-0.02867 Cycle 21
0.64285 Cycle 22
0.76732
0.52019
0.63700
0.06950 Cycle 23
Correlation coefficients of the entire and
cyclic yearly mean data sets. Significant
coefficents are given in bold face type.
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(e)
60-70
(d) 50-60
(c) 40-50
(b) 30-40
(a) FI
Comparison of the temperature anomalies of four sub-regions with
solar flare index anomalies. Dashed vertical lines mark the solar
activity cycle maxima.
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In order to compare the spectral characteristics of
the flare index to the spectral characteristics of
surface air temperature we used multi taper method
(MTM). Data frequency range was selected from
0.005 to 0.07 (14 - 200 months) and 0.005 to 0.08
(12.5 - 200 months) for temperature and FI data sets
respectively. Our significance test are carried out
with respect to red noise, since the temperature
records, like most climatic and other geophysical
time series, have larger power at lower frequencies.
All harmonic signals obtained by using of 95 %
confidence level.
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Multi taper method analysis of the 33 years long of the
solar flare index from 1975 to 2007. Horizontal lines show
the significant levels corresponding to red noise spectrum
at 90, 95, and 99% confidence limits.
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Multi taper method analysis of the 33 years long surface air
temperature of the four sub-regions from 1975 to 2007.
Horizontal lines show the significant levels corresponding
to red noise spectrum at 90, 95, and 99% confidence limits.
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Periodical analysis results show that all sub-regions
temperature data sets have all about the same
periodicity, albeit showing small differences
There are two meaningful groups of periods for the
surface air temperature, which are at 1.3–1.8 and 2.4-2.6
years. The first group found in our study was reported by
Kirivova and Solanki (2002) when analyzing the sunspot
areas and the sunspot number data, respectively for the
1880 – 2000 and the 1750 – 2000 time periods.
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Such a period of ~1.3-year can be a sub-harmonic of other
periodic effects including the well known Schwabe cycle
(10.5-year). This issue may be related to the quasi-biennial
oscillations of occurring in the stratospheric winds. This is
a possibility.
Obridko and Shelting (2007) recently reported that
oscillations of 1.3-yr period are closely associated with
quasi-biennial oscillations of large-scale solar magnetic
field. This is another possibility.
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Spectral analysis of 60 - 70 degree group shows 5.7
years periodicity. This period may be related to
geomagnetic activity (5.25-year) and of course indirectly
to solar activity. However using the geomagnetic activity
index aa, Kane (1997) found a QBO and a 5.4-years
periodicity during the period of time 1868 – 1994. This
periodicity was also reported in the biological and
biophysical studies. Nevertheless, such a period is not
seen in the flare index spectral analysis.
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FI and temperature anomalies show an opposite behavior from
1982 to 1985 and from1991 to 1994. It is interesting to note that at
the same time periods there were strong volcanic activities (March
28, 1982, El Chichon; 17.4N, 93.2W; and April 2, 1991, Pinatubo;
15.13N, 120.35E) and as seen in figure below, the net solar
radiation decreased remarkably as measured at Mauna Loa
observatory (19.54N, 155.58W).
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(e)
60-70
(d) 50-60
(c) 40-50
(b) 30-40
(a) FI
Dotted vertical lines mark the beginning of the two volcanic
activities, El Chichon and Pinatuba, respectively.
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There is growing evidence that solar variability drives the
Earth climate system in various ways and on multiple time
scales resulting in various proxies. A list of these proxies
can be found for instance in Rozelot (1990). Among all of
them, the tree-ring time series is not frequently used but
might be significant. For instance suppressed time of solar
activity is well marked (Mauder Minimum), simply due to the
influence of the climate on the growth of the trees.
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Recently Rigozo et al., (2007) have found evidence for the
presence of the solar activity long term periods (~11, 22, 80,
and 208 years) by examining the tree ring time series
extended over a period of 400 years. They have also reported
that these periods are intermittent, possibly because solar
activity signals observed in the tree rings are mostly due to
solar influence on local climate.
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Conclusions
Signatures of solar activity effect exist on surface air
temperature of some mid-latitude regions according
to our statistical analysis and over the considered
period of time.
Investigation of Sun-climate relationship on local
scale may give better possibilities for understanding
of the problem than global scale.
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References
Kane, R. P., 1997. Quasi-biennial and quasi-triennial oscillations
in geomagnetic activity indices. Annales Geophysicae 15, 1581-1594.
Krivova, N.A., and Solanki, S.K., 2002. The 1.3-year and 156-day
periodicities in sunspot data: Wavelet analysis suggests a common origin.
Astronomy and Astrophysics 394, 701–706.
Obridko, VN; Shelting, BD, 2007. Occurrence of the 1.3-year
periodicity in the large-scale solar magnetic field for 8 solar cycles.
Advances in Space Research 40, 1006-1014.
Rigozo, N. R.,Nordemann, D.J.R., Souza Echer, M.P., Echer, E.,
da Silva, H.E., Prestes, A., Guarnieri, F.L., 2007. Solar activity imprints in
tree ring width from Chili (1610-1991). JASTP 69, 1049-1056.
Rozelot, J.P., 1990. Historical reconstruction of past solar cycles
and links with the Earth climate. In "New approaches in Geomagnetism
and the Earth's Rotation", ed. S. Flodmark, World Scientific, London, pp.
245-253.
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THANK YOU
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