Total methane content in the atmosphere of Western Siberia in 2000–2020 according to the data of chemical transport model MOZART-4

Abstract

The paper considers the behavior of total methane content in the atmosphere of Western Siberia obtained using the global chemical transport model MOZART-4 (Model for OZone And Related chemical Tracers, version 4). We discuss details of the model configuration for simulation of methane content until the end of the XXI century within the Representative Concentration Pathways (RCP4.5 and RCP8.5). Boundary conditions at the lower levels of the model (methane content in the surface air layer) was obtained using data from the Earth System Research Laboratories (ESRL) project and the results of the Atmospheric Chemistry-Transport Models (ACTM) for 2007–2010. The methane content in the stratosphere was also defining according to the ACTM results. The climate data used in MOZART-4 is based on the results of the Goddard Earth Observing System, Version 5 (GEOS-5). The modification of the boundary conditions carried out in the work made it possible to reproduce the summer and winter maximum in the annual course of CH4. These results are confirmed by satellite and aircraft observations made on the territory of Western Siberia. It was found that the total methane content in the atmosphere of the studied region (45–65 N, 60–90 E) in 2000–2020 increased with a trend of about 3.5 ± 0.2 ppb/year. In 2000–2006, there is virtually no trend. The increase of CH4 in 2007–2020 has a trend of ∼ 5.0 ± 0.2 ppb/year. The global data obtained as a result of the simulation can be used as initial and boundary conditions of the chemical version of the regional climate model RegCM-CHEM4.

Regression model for reconstruction of the total methane content according to the data from AIRS hyperspectrometer and chemical transport model MOZART-4

“…Also, the results of the model show a high agreement with the MOZART-4 data, where the correlation coefficient lies in the range 9 … 97. The obtained values of indicate a significant increase in the predictive quality of the model compared to the first version proposed by us in 8 .…”

“…Note that the modified version of the model made it possible to take into account the anomalies in the spatial distribution o f the surface methane concentration, for example, in the area of the Great Vasyugan Mire, as well as the global trend in the change in the methane concentration in the surface layer. An additional comparison of the MOZART-4 results with the observations of the TCCON network of ground-based stations 11 showed a good agreement between the model data and the measurements 10 . MOZART-4 results were used in the training phase of the regression model.…”

“…The considered regression model is a further development of the approach proposed by the authors in 8 . At the preparatory stage, the global chemical transport model MOZART-4 modified by the authors was verified.…”

“…At the preparatory stage, the global chemical transport model MOZART-4 modified by the authors was verified. The results of computational experiments using MOZART-4, which describe the behavior of methane at the lower and upper boundaries of the simulation region, are given in 9,10 . Note that the modified version of the model made it possible to take into account the anomalies in the spatial distribution o f the surface methane concentration, for example, in the area of the Great Vasyugan Mire, as well as the global trend in the change in the methane concentration in the surface layer.…”

A Smart Post-Processing System for Forecasting the Climate Precipitation Based on Machine Learning Computations

“…During the last decade, this research area was very active and many statistical and computational methods have been studied [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63]. In another study, Scheuerer et al [64] proposed a statistic method for post-processing temperature ensemble forecasts in COSMO-DE [64].…”