Ecoinformatics Problems of Global Climate Change - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 395

Feldstein and Franzke (2006) examined composites of the sea level pressure,
40-h Pa, and 300-h Pa streamfunction fields during NAO and NAM persistent events

to test null hypothesis. Standard statistical techniques were used, such as t tests for the
differences of means. This study addresses the question of whether persistent events
of the NAO and the NAM teleconnection patterns are distinguishable from each
other. Standard daily index time series are used to specify the amplitude of the NAO
and NAM patterns. It is found that the null hypothesis cannot be rejected even at the
80 % con

dence level. The wave-breaking characteristics during the NAM life cycle
are also examined. Both the positive and negative NAM phases yield the same wave-
breaking properties as those for the NAO. The results suggest that not only are the
NAO and NAM persistent events indistinguishable, but that the NAO/NAM events
are neither con ned to the North Atlantic, nor are they annular.

The observational data show that during the 20th century an increase of pre-
cipitation constituted 0.5

1 % per 10 years over most of land surface in the middle
and high latitudes of the Northern Hemisphere, but a decrease (by about 0.3 % per
10 years) took place over most of land surface in sub-tropical latitudes, which has
recently weakened, however. As for the World Ocean,

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the lack of adequate

observational data has not permitted the identi cation of any reliable trends of

precipitation. In recent decades, intensive and extreme precipitation in the middle
and high latitudes of the Northern Hemisphere has probably become more frequent.
Beginning from the mid-1970s the ENSO events have been frequent, stable and
intensive. This ENSO dynamics was re c regional variations of

precipitation and SAT in most of the zones of the tropics and sub-tropics. Data on
the intensity and frequency of occurrence of the tropical and extratropical cyclones
as well as local storms still remain fragmentary and inadequate and do not permit to
draw conclusions on any trends.
Changes in the biosphere are also important indicators of climate. One of them is
the bleaching of corals. It is important to recognize that enhanced atmospheric
forcings on coral reefs do not lead to their disappearance but to their transformation
into more resistant species (Chin 2011; Hughes et al. 2003). Changes of sea water
properties are one more indicator (Broecker 2003). The properties of sea water are a
function of temperature, salinity (i.e. total dissolved solids in g kg − 1 ) and pressure
(Table 5.6 ).

fl ected in speci

5.3.6 Concentrations of Greenhouse Gases
and Anthropogenic Aerosol in the Atmosphere

A greenhouse gas (GHG) is a gas in an atmosphere that absorbs and emits radiation
within the thermal infrared range. This process is the fundamental cause of the
greenhouse effect. The primary greenhouse gases in the Earth s atmosphere are

water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Table 5.7 contents
list of greenhouse gases and their characteristics related to the climate. Aside from
water vapor, which has a residence time of about 9 days, major greenhouse gases

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