Regional Representativeness of CH4 and N2O Mixing Ratio Measurements at High-Altitude Mountain Station Kasprowy Wierch, Southern Poland

Jaroslaw M Ne?Cki,Christoph Gerbig,Lukasz Chmura,Jakub Bartyzel,Wojciech Wolkowicz,Damian Zie?Ba,Miroslaw Zimnoch,Kazimierz Ro´Z?An´Ski,Michal Galkowski

doi:10.4209/aaqr.2015.05.0357

Abstract

Records of trace gas composition of the atmosphere originating from mountain stations are difficult to interpret in terms of continental gas balances due to complex topography and local wind patterns. Kasprowy Wierch station, located in the High Tatra Mountains, Poland, provides datasets to European GHG databases and can be used for regional and continental balances of trace gases in Earth's atmosphere. Although it suffers from strong influence of local valley winds, the concentration record obtained at Kasprowy Wierch contains also a discernible fraction of methane (up to 100 ppb) emitted mainly by large regional source of this gas (Silesian Coal Basin) located ca. 150 km north-west of Kasprowy Wierch. Comparison of GOSAT satellite CH_4 record in the pixel including High Tatras at the level of 850 hPa with the data obtained at Kasprowy Wierch mountain station revealed surprisingly good correlation, even for relatively short time intervals.

Highlights

Methane (CH4) is one of the major greenhouse gases actively changing radiative forcing of the Earth’s atmosphere (Hofmann et al, 2006; Myhre et al, 2013)
KAS station located in the High Tatra Mountains, southern Poland, is the easternmost high altitude station in Europe where regular measurements of atmospheric mixing ratios of CH4 and N2O are being performed
The footprint of this station calculated using Stochastic Time-Inverted Lagrangian Transport (STILT) model shows that the site can be used for estimation of the source strength of those gases distributed over the region of central Europe, covering Poland, Slovakia, large part of Czech Republic, Hungary, eastern part of Germany, Romania, Balkan countries and Ukraine

Summary

Introduction

Methane (CH4) is one of the major greenhouse gases actively changing radiative forcing of the Earth’s atmosphere (Hofmann et al, 2006; Myhre et al, 2013). During the last three decades, globally averaged trends of methane concentrations revealed three distinctive phases of change: (i) strong increase from 1984 to 1992, (ii) a period of relative stability during 1992-2008, and (iii) renewed significant increase since 2009 (Dlugokencki et al, 1994; Rigby et al, 2008; Dlugokencki et al, 2009; Kai et al, 2011). While the main sources and sinks of CH4 are relatively well constrained on the global scale, the reasons behind the stabilization of atmospheric CH4 levels during the first several years of the 21st century are still under debate, underlining the need for better understanding of its sources and sinks on local and regional scales. Global and regional budgets of N2O are still uncertain, pointing to the need of further studies of its emission and transport patterns on various temporal and spatial scales

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