scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...

STP12 Abstracts
Berlin, 12 - 16 July 2010
SCOSTEP Symposium 2010
On characteristic features of global, polar and equitorial temperature and its possible
linkage with solar activities.
Banerjee Dhruba 1 , Bondyopadhaya Ramaprosad 2
1 Faculty Member,Department of Physics,Swami Vivekananda Institute of Science and
Technology,Kolkata- 145,India, 2 Professor,Mathematics Department,Jadavpur University,Kolkata-
32,India
The temperature of Land and Ocean, and Global Land -Ocean Temperature (GLOT) for the period
1880-2006 have been considered. Further, the Land and Ocean temperature during last century (1903-
2006) for Polar region and Equatorial region have been analyzed and compared.
The analysis reveals (i) the temperature anomaly curve of GLOT has always positive gradient
but the gradient during 1947 to 2006 is almost 1.7 times that of during the 1880-1946.
(ii)Although the overall trend is increasing from 1880 onwards there exists an oscillatory trend in both
Land and Ocean temperature anomalies separately and also in GLOT, but significantly in the last 26/
27 years (i.e.1979/80 to 2006) the rate of increase of temperature for all three cases (Land, Ocean and
GLOT), however, becomes much higher than that of previous 100 years. Consistently with this trend,
the correlation coefficient (c.c.) between temperature anomalies and time during this period comes out
to be quite high (+0.79 for both Land and Ocean, and +0.86 for GLOT).Clearly, these are all
signatures of the so called Global Warming.
However, the comparison of the trend lines for temperature variation of Antarctic, Arctic and
Equatorial regions during last 100 years(1903-2006) indicate that the rate of increase of temperature is
positive everywhere but significantly it is maximum in Antarctic ,which is almost double that of
Arctic, and almost four times that of Equatorial region. Further, in general, the nature of variation of
Arctic and Antarctic temperature are opposite in character. e.g. Arctic temp. curve exhibits long period
oscillation from 1913 to1963 and then continues to increase while Antarctic curve exhibits rapid
fluctuation up to 1963/64 and then increase rapidly. This also implies Global Warming exist but not
uniform everywhere.
When the trend of Global Land-Ocean Temperature (GLOT) is compared with that for Sun’s
Spot Number (SSN) for the period 1880-2006.It is found that the same monotonically increasing trend
exists in the variation of SSN as well as in GLOT.Finally, the comparison of correlation coefficients
between SSN and Temperature in different regions (Arctic, Antarctic and Equatorial) for different
SSN ranges revel that SSN is most capable to influence in Eqatorial region. But always exist some
critical value of SSN (≈120) exceeding which solar influence becomes more effective.