Linking air stagnation in Europe with the synoptic-to-large-scale atmospheric circulation

• Published in: Weather and Climate Dynamics
• Main Authors: Maddison J.W., Abalos M., Barriopedro, David, García-Herrera R., Garrido-Perez J.M., Ordóñez C.
• Other Authors: Ministerio de Economía y Competitividad (España), Ministerio de Economía, Industria y Competitividad (España)
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: European Geosciences Union 2021
• Subjects: North Atlantic
• Online Access: http://hdl.handle.net/10261/342342; https://doi.org/10.5194/wcd-2-675-2021

The build-up of pollutants to harmful levels can occur when meteorological conditions favour their production or accumulation near the surface. Such conditions can arise when a region experiences air stagnation. The link between European air stagnation, air pollution and the synoptic- to large-scale circulation is investigated in this article across all seasons and the 1979¿2018 period. Dynamical indices identifying atmospheric blocking, Rossby wave breaking, subtropical ridges, and the North Atlantic eddy-driven and subtropical jets are used to describe the synoptic- to large-scale circulation as predictors in statistical models of air stagnation and pollutant variability. It is found that the large-scale circulation can explain approximately 60¿% of the variance in monthly air stagnation, ozone and wintertime particulate matter (PM) in five distinct regions within Europe. The variance explained by the model does not vary strongly across regions and seasons, apart from for PM when the skill is highest in winter. However, the dynamical indices most related to air stagnation do depend on region and season. The blocking and Rossby wave breaking predictors tend to be the most important for describing air stagnation and pollutant variability in northern regions, whereas ridges and the subtropical jet are more important to the south. The demonstrated correspondence between air stagnation, pollution and the large-scale circulation can be used to assess the representation of stagnation in climate models, which is key for understanding how air stagnation and its associated climatic impacts may change in the future. This work has been funded by the Spanish Ministerio de Economía, Industria y Competitividad under grant CGL2017- 83198-R (STEADY) and Ministerio de Ciencia Innovación y Universidades, under grant RTI2018-096402-B-I00 (JeDiS). MA was supported 490 by the Program Atracción de Talento de la Comunidad de Madrid (2016-T2/AMB-1405), JMGP by a predoctoral research grant awarded by the Spanish Ministerio de ...