Geoscience Reference
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Sahin and Cigizoglu (2010) performed homogeneity analysis of the
maximum air temperature, the minimum air temperature, the mean air
temperature, the total precipitation, the relative humidity and the local pressure
of 232 stations of Turkey for the period 1974-2002. The homogeneity analysis
was performed on the annual data using a relative test and four absolute
homogeneity tests were used for the stations where non-testable series were
found due to the low correlation coefficients between the test and the reference
series. A comparison was accomplished by the graphics where relative and
absolute tests provided different outcomes. Absolute tests failed to detect the
inhomogeneities in the precipitation series at a significance level of 1%.
Interestingly, most of the inhomogeneities detected on the temperature variables
existed in the Aegean region of Turkey. It is considered that these
inhomogeneities were mostly caused by non-natural effects such as relocation.
Because of changes in topography at short distance in this region, non-random
characteristics of the temperature series are intensified when relocation occurs
even in small distances. The marine effect, which causes artificial cooling
effect due to sea breezes, has important impact on temperature series and the
orography allows this impact go through the inner parts in this region.
6.2.2 Air and Water Temperature
Esteban-Parra and Castro-Diez (1995) analyzed the longest annual and seasonal
series of maximum, minimum and average temperatures of some localities in
Spain. The homogeneity was checked by using the Thom and Bartlett tests.
These methods are reported to yield different results in some cases. The
analysis was performed to explore how the existence of actual trends and/or
discontinuities in the series affects the sensitivity and have a repercussion on
the results of the tests. This analysis suggested an adequate confidence level
and the need of the use of relative homogeneity tests.
Webb (1996) analyzed the future trends in water temperatures from
different parts of the world. The potential causes of trends in the thermal
regimes of streams and rivers are many, but the existing database of water
temperature was found inadequate to provide a global perspective on changes
during the recent past. The data from Europe suggested that an increase of up
to 1°C in the mean river water temperatures has occurred during the 20 th
century. However, this trend was not found continuous and correlated with
simple hydrometeorological factors, rather it was found to be distorted by
extreme hydrological events influenced by a variety of human activities.
Predictive studies indicated that an accelerated rise in stream and river water
temperatures will occur during the next century because of global warming.
However, the forecasts are tentative because future climatic conditions are
uncertain, and the interactions between climate and hydrological and vegetation
changes are complex.
Tayanç and Toros (1997) studied the daily maximum temperature and
temperature difference series (1951-1990) of four urban stations and their
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