“Quantification of CH4 emissions from waste disposal sites near the city of Madrid using ground- and space-based observations of COCCON, TROPOMI and IASI”, paper published in ACPD
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The objective of this paper is to derive methane (CH4) emissions of the metropolitan city Madrid Spain from the CH4 enhancements seen by the space-borne and the ground-based instruments. This study applies satellite-based measurements from the TROPOspheric Monitoring Instrument (TROPOMI) and the Infrared Atmospheric Sounding Interferometer (IASI) together with measurements from the ground-based COllaborative Carbon Column Observing Network (COCCON) instruments.
In 2018, a two-week field campaign for measuring the atmospheric concentrations of greenhouse gases was performed in Madrid in the framework of Monitoring greenhousE Gas EmIssions of Madrid city (MEGEI-MAD) project. Five COCCON instruments were deployed at different locations around the Madrid city center enabling the observation of total column averaged CH4 mixing ratios (XCH4). Using available wind data, the differences between CH4 columns observed at these locations allow to estimate the emissions emerging from the surrounded area. In addition, based on the dominating wind direction in the Madrid region, we calculate the difference of the satellite data maps for two opposite wind regimes (northeast – southwest, NE – SW) during the period 2017-2020, obtaining pronounced bipolar CH4 plumes along NE and SW wind direction. This analysis is also applied to the tropospheric and upper tropospheric/stratospheric column averaged CH4 mixing ratio products (TXCH4 and UTSXCH4, respectively) derived from a-posteriori merged Infrared Atmospheric Sounding Interferometer (IASI) profile and TROPOMI total column data (Figure 1).
Figure 1: (a-c) XCH4, (d-f) TXCH4 and (g-i) UTSXCH4 anomalies for the entire 2017-2020 period, days with SW wind and NE wind directions. The triangle symbols represent the location of waste plants around Madrid city.
Based on the NE and SW wind fields, we developed a simple plume model locating the source at three waste disposal sites east of Madrid for CH4. As CH4 emission strength we estimate 7.4 × 1025 ± 6.4 × 1024 molec s−1 from the TROPOMI XCH4 data and 7.1 × 1025 ± 1.0 × 1025 molec s−1 from the TROPOMI&IASI merged TXCH4 data. The COCCON observations indicate a weaker CH4 emission strength of around 3.7 × 1025 molec s−1 from local source (near to the Parque Tecnológico Valdemingómez waste plant) in accordance with observations in a single day. All emission rates estimated from the different observations are significantly larger than the emission rates provided via the official Spanish Register of Emissions and Pollutant Sources.
For further details refer to: Tu, Q., Hase, F., Schneider, M., García, O., Blumenstock, T., Borsdorff, T., Frey, M., Khosrawi, F., Lorente, A., Alberti, C., Bustos, J. J., Butz, A., Carreño, V., Cuevas, E., Curcoll, R., Diekmann, C. J., Dubravica, D., Ertl, B., Estruch, C., León-Luis, S. F., Marrero, C., Morgui, J.-A., Ramos, R., Scharun, C., Schneider, C., Sepúlveda, E., Toledano, C., and Torres, C.: Quantification of CH4 emissions from waste disposal sites near the city of Madrid using ground- and space-based observations of COCCON, TROPOMI and IASI, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-437, in review, 2021. https://acp.copernicus.org/preprints/acp-2021-437/
