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| Titel |
Fifteen years of atmospheric methane and carbon dioxide mixing ratio measurements at the mountain site Kasprowy Wierch, southern Poland |
| VerfasserIn |
L. Chmura, A. Korus, J. Necki, K. Rozanski, M. Zimnoch |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250021404
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| Zusammenfassung |
| The Kasprowy Wierch station is located in the south of Poland, within the High Tatra
Mountains. The meteorological observatory which hosts the monitoring station is located
on top of a mountain peak called Kasprowy Wierch (49o14’N, 19o59’E, 1989 m
a.s.l., 300 m above the tree line). Climate of Kasprowy Wierch area is typical for a
continental mountain location, with relatively large diurnal and seasonal variations of
temperature, high precipitation rate, frequent changes of atmospheric pressure and strong
winds.
Regular observations of atmospheric CH4 and CO2mixing ratios at Kasprowy Wierch
begun in 1994. Continuous measurements using GC technique were initiated in 1996. The
available dataset of CO2 and CH4mixing ratios at Kasprowy Wierch comprise a valuable
source of information about temporal variability of those gases in the atmosphere above
central Europe over 15-year period.
Significant year-to-year variability of carbon dioxide mixing ratio, both with respect to
the observed annual growth rate as well as the amplitude of seasonal changes, was observed.
The presented carbon dioxide mixing ratio record reveals typical behaviour of atmospheric
CO2 observed at mid-latitude continental sites of the Northern Hemisphere. The winter
maximum ends in spring, when the photosynthetic sink starts to operate. From
that time on, the CO2 mixing ratio gradually decreases, reaching a minimum in
August/September. Afterwards, the CO2 level increases, reaching winter maximum
in February/March. The length of the CO2 deficit season at Kasprowy Wierch,
defined as the period when CO2 mixing ratio remains below the long-term trend
curve, is getting shorter (c.a. -0.5 ppm year-1, averaged over the observation period
1994-2008). The average peak-to-peak amplitude for the period 1994-2008 is equal c.a. 19
ppm (minimum value of 14,7 ppm recorded in 2003 and maximum of 20,7 ppm
recorded in 1995). It is worth to note that the 2003 summer draw-down of CO2
concentration at Kasprowy Wierch was anomalously low (peak-to-peak amplitude of 14.7
ppm, when compared to 20.1 ppm in 2002 and 18.1 ppm in 2004). This effect was
most probably linked to extreme heat wave in summer 2003 which affected mostly
western Europe and reduced photosynthetic activity on large areas of the European
continent. The mean annual growth-rate of CO2 mixing ratio at Kasprowy Wierch,
averaged over the observation period (1994-2008), is equal approximately 2 ppm
year-1. This value is comparable to other “clean” stations located in European
continent.
No significant seasonal cycle of methane has been detected at Kasprowy Wierch.
Apparently, the weak seasonal signal, connected with seasonality of UV radiation and
concentration of OH radicals, is overshadowed by relatively strong, mainly anthropogenic
emissions of CH4, related to ruminants, leakages from natural gas supply, coal mining and
waste deposits, which are not likely to vary significantly with season. The annual
growth-rate of methane mixing ratio at Kasprowy Wierch, averaged over the observation
period (1994-2008), is equal c.a. 2 ppb year-1. The mean level of CH4 mixing
ratio recorded in 2007 (1843.5 ppb) is comparable with other European stations. |
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