Find in Library

<p>Intensive coal mining activities in the Upper Silesian Coal Basin (USCB) in southern Poland are resulting in large amounts of methane (<span class="inline-formula">CH₄</span>) emissions. Annual <span class="inline-formula">CH₄</span> emissions reached 448 kt according to the European Pollutant Release and Transfer Register (E-PRTR, 2017). As a <span class="inline-formula">CH₄</span> emission hotspot in Europe, it is of importance to investigate its emission sources and make accurate emission estimates.</p> <p>In this study, we use satellite-based total column-averaged dry-air mole fraction of <span class="inline-formula">CH₄</span> (<span class="inline-formula">XCH₄</span>) from the TROPOspheric Monitoring Instrument (TROPOMI) and tropospheric <span class="inline-formula">XCH₄</span> (<span class="inline-formula">TXCH₄</span>) from the Infrared Atmospheric Sounding Interferometer (IASI). In addition, the high-resolution model forecasts, <span class="inline-formula">XCH₄</span> and <span class="inline-formula">TXCH₄</span>, from the Copernicus Atmosphere Monitoring Service (CAMS) are used to estimate the <span class="inline-formula">CH₄</span> emission rate averaged over 3 years (November 2017–December 2020) in the USCB region (49.3–50.8<span class="inline-formula">^∘</span> N and 18–20<span class="inline-formula">^∘</span> E). The wind-assigned anomaly method is first validated using the CAMS forecast data (<span class="inline-formula">XCH₄</span> and <span class="inline-formula">TXCH₄</span>), showing a good agreement with the CAMS GLOBal ANThropogenic emission (CAMS-GLOB-ANT) inventory. It indicates that the wind-assigned method works well. This wind-assigned method is further applied to the TROPOMI <span class="inline-formula">XCH₄</span> and TROPOMI <span class="inline-formula">+</span> IASI <span class="inline-formula">TXCH₄</span> by using the Carbon dioxide and Methane (CoMet) inventory derived for the year 2018. The calculated averaged total <span class="inline-formula">CH₄</span> emissions over the USCB region is about 496 kt yr<span class="inline-formula">⁻¹</span> (<span class="inline-formula">5.9×10²⁶</span> molec. s<span class="inline-formula">⁻¹</span>) for TROPOMI <span class="inline-formula">XCH₄</span> and 437 kt yr<span class="inline-formula">⁻¹</span> (<span class="inline-formula">5.2×10²⁶</span> molec. s<span class="inline-formula">⁻¹</span>) for TROPOMI <span class="inline-formula">+</span> IASI <span class="inline-formula">TXCH₄</span>. These values are very close to the ones given in the E-PRTR inventory (448 kt yr<span class="inline-formula">⁻¹</span>) and the ones in the CoMet inventory (555 kt yr<span class="inline-formula">⁻¹</span>), and are thus in agreement with these inventories. The similar estimates of <span class="inline-formula">XCH₄</span> and <span class="inline-formula">TXCH₄</span> also imply that for a strong source, the dynamically induced variations of the <span class="inline-formula">CH₄</span> mixing ratio in the upper troposphere and lower stratosphere region are of secondary importance. Uncertainties from different error sources (background removal and noise in the data, vertical wind shear, wind field segmentation, and angle of the emission cone) are approximately 14.8 % for TROPOMI <span class="inline-formula">XCH₄</span> and 11.4 % for TROPOMI <span class="inline-formula">+</span> IASI <span class="inline-formula">TXCH₄</span>. These results suggest that our wind-assigned method is quite robust and might also serve as a simple method to estimate <span class="inline-formula">CH₄</span> or <span class="inline-formula">CO₂</span> emissions for other regions.</p>