Simulation of transport and composition changes during a blocking episode over the East Atlantic and North Europe

Ebel, A.; Feldmann, Hendrik; Jakobs, H. J.; Memmesheimer, M.; Offermann, D.; Kuell, V.; Schäler, B.

doi:10.1016/j.ecolmodel.2008.06.014

Cited by 4 publications

(4 citation statements)

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“…An even higher resolution is desirable for catching also the details in the lower troposphere. Episodic studies with the EU-RAD model (ATMOFAST, 2005;Ebel et al, 2008) with increased horizontal and vertical resolution confirmed that especially a higher vertical resolution in the tropopause region enhances the ability of the model to reproduce of the dynamics and composition of the upper troposphere/lower stratosphere in more detail.…”

Section: Discussionmentioning

confidence: 89%

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Forecasted deep stratospheric intrusions over Central Europe: case studies and climatologies

et al. 2010

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Abstract. Based on daily predictions of stratospheric air intrusions, obtained from trajectory calculations by ETH Zürich with wind fields from ECMWF forecasts, a high number of measurements with the ozone lidar at IMK-IFU (Garmisch-Partenkirchen, Germany) were carried out in 2001. The lidar measurements show a large variety of rather different cases reflecting the full complexity of intrusion episodes that is not visible in classical case studies. In part, tropopause folds could be fully captured. The frequency of intrusion cases forecasted and verified by vertical sounding or in the in-situ data recorded at the nearby Zugspitze summit (2962 m a.s.l.) exceed that in previous work by more than a factor of two. Three cases mapped with the lidar were selected to validate the results for the corresponding time periods extracted from a one-year run with the new hemispheric version of the chemistry-transport model EURAD. Due to the high spatial resolution chosen for these simulations the agreement with the lidar measurements is satisfactory. The Zugspitze ozone data from 1978 to 2004 were recently filtered by applying different criteria for stratospheric air, based on the 7 Be and humidity measurements. Here, by using the daily model forecasts during the time period 2001-2005, we examine three criteria and determine how well they represent the stratospheric air intrusions reaching the mountain site. Seasonal cycles for the period 2001-2005 were derived forCorrespondence to: T. Trickl (thomas.trickl@kit.edu) the forecasts as well as the intrusion frequency per month for the forecasted intrusions and each of the criteria, distinguishing eight different characteristic transport pathways. In most cases a winter maximum and a summer minimum was obtained, but in the case of cyclonic arrival of intrusions starting over Greenland a late-spring maximum is seen. Two of the filtering criteria examined, based on combining a relativehumidity (RH) threshold of 60% with either a 7 Be threshold of 5.5 mBq m −3 or the requirement for RH≤30% within ±6 h, rather reliably predict periods of deep intrusions reaching the Zugspitze station. An "or" combination of both these criteria yields slightly more cases and covers 77.9% of the intrusions identified. The lack of observations in the complementary 22.1% are mostly explained by overpasses. In this way the long-term trend of stratospheric ozone observed at this site as well as the corresponding ozone budget may be derived on the basis of measurements only. This effort will be the subject of a subsequent publication.

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Section: Discussionmentioning

confidence: 89%

“…Single episodes and longer periods have been studied with this modified version of EURAD (e.g., Ebel et al, 2008). In particular, a full-year run was completed for 2001.…”

Section: Models Used For the Analysismentioning

confidence: 99%

Forecasted deep stratospheric intrusions over Central Europe: case studies and climatologies

et al. 2010

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“…As indicated by Shapiro et al (1987) and Hudson et al (2003), there is a close coincidence between the SJS and the upper-level subtropical front, where shallow tropopause foldings are likely to occur (Langford 1999). In particular, the mixing of stratospheric air into the troposphere can occur at the western and eastern boundary of the blocking system, where a very low tropopause (occasionally close to the 5000-hPa pressure level) can occur (Ebel et al 2008). Exchange can also occur as a result of filamentation around the SJS, causing a quasihorizontal stretching of stratospheric materials along isentropes (Appenzeller and Holton 1997).…”

Section: Resultsmentioning

confidence: 99%

Transport of Stratospheric Air Masses to the Nepal Climate Observatory–Pyramid (Himalaya; 5079 m MSL): A Synoptic-Scale Investigation

Bracci

Cristofanelli

Sprenger

et al. 2012

Journal of Applied Meteorology and Climatology

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This work analyzes and classifies stratospheric airmass transport events (ST) detected at the Nepal Climate Observatory-Pyramid (NCO-P; 278579N, 868489E, 5079 m MSL) Global Atmospheric Watch-World Meteorological Organization station from March 2006 to February 2008. For this purpose, in situ ozone (O 3 ), meteorological parameters (atmospheric pressure and relative humidity), and black carbon (BC) are analyzed. The paper describes the synoptic-scale meteorological scenarios that are able to favor the development of ST over the southern Himalaya, by analyzing the meteorological fields provided by the ECMWF model (geopotential height, wind speed, and potential vorticity), satellite Ozone Monitoring Instrument data (total column ozone), and three-dimensional back trajectories calculated with the Lagrangian Analysis Tool (LAGRANTO) model. The study, which represents the first ''continuous'' classification of ST in the southern Himalaya, permitted classification of 94% of ST days within four synoptic-scale scenarios: stratospheric potential vorticity structures (PVS), subtropical jet stream (SJS), quasi-stationary ridges (QSR), and monsoon depressions (MD). SJS and PVS were the most frequent scenarios (48% and 30% of occurrences, respectively), QSR occurred for 12% of the ST days, and MD were detected only during the monsoon season (3%). SJS and PVS scenarios presented a peak frequency during the nonmonsoon seasons, when the jet stream and westerly disturbances influence atmospheric circulation over the southern Himalaya. During the identified ST, significant variations of O 3 (124%) and BC (256%) were recorded relative to the averaged 2-yr mean values. On average, PVS and SJS were the most effective synoptic-scale scenarios in modifying the O 3 and BC levels at NCO-P from postmonsoon to premonsoon seasons, and ST is one of the leading processes in defining the ''background'' BC variability at NCO-P.Corresponding author address: P. Cristofanelli,

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“…The climate changes and primarily the global increase of the temperature are already causing or at least will cause in the future many difficulties in the modern society. This is becoming clear from the conclusions drawn by the specialists from the Intergovernmental Panel on Climatic Changes (IPCC) in Houghton et al (2001) and Stocker et al (2013) or by many other scientists working in this area (Bell et al, 2007;Bouchet et al, 1999aBouchet et al, , 1999bCarvalho et al, 2010;Ebel et al, 2008;Jacobson, 2008;Richardson, 1911;Syrakov et al, 2011). We shall show in this paper that the climate changes may lead to some increases of ozone pollution levels, which could result in difficulties for some groups of people (persons suffering from asthmatic diseases).…”

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confidence: 77%

Advanced algorithms for studying the impact of climate changes on ozone levels in the atmosphere

Zlatev

Dimov

Faragó

et al. 2019

IJEP

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The impact of the increased temperature on some pollution levels is studied by developing climate scenarios and by running them on a period of 16 consecutive years. The mathematical model used in the experiments is a system of nonlinear partial differential equations (PDEs) and the space domain contains the whole of Europe together with some of its surroundings. Difficult computational problems arise after the direct discretisation of the spatial derivatives in the equations. The enormous computational problems can be treated successfully only by resolving five important tasks: 1) applying accurate and efficient numerical algorithms; 2) selecting an appropriate splitting procedure; 3) developing parallel codes; 4) using high-speed computers; 5) exploiting well the cache memories of the parallel computers. Numerical results will be presented in order to illustrate both the efficiency of the code and the fact that the future climate changes will result in consistent increase of some pollution levels.

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Simulation of transport and composition changes during a blocking episode over the East Atlantic and North Europe

Cited by 4 publications

References 45 publications

Forecasted deep stratospheric intrusions over Central Europe: case studies and climatologies

Forecasted deep stratospheric intrusions over Central Europe: case studies and climatologies

Transport of Stratospheric Air Masses to the Nepal Climate Observatory–Pyramid (Himalaya; 5079 m MSL): A Synoptic-Scale Investigation

Advanced algorithms for studying the impact of climate changes on ozone levels in the atmosphere

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