Increase in the number of extremely strong fronts over Europe? A study based on ERA‐Interim reanalysis (1979–2014). Issue 1 (12th January 2017)

• Record Type: Journal Article
• Authors: Schemm, S.; Sprenger, M.; Martius, O.; Wernli, H.; Zimmer, M.
• Is Part Of: Geophysical research letters. Volume 44:Issue 1(2017)
• Page Start: 553
• Page End: 561
• Publication Date: 2017-01-12
• Subjects: high‐impact weather -- weather front -- precipitation -- trend -- extreme event; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL071451
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Evidence is presented that the frequency of extremely strong fronts, which occur mainly in summer, has increased over Europe in ERA‐Interim reanalyses data (1979–2014). Fronts are defined using a common detection scheme based on gradients of equivalent potential temperature ( θ e ) at 850 hPa. The frequency increase is due to increasing atmospheric humidity, which in turn is reported as statistically significant over Europe in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). There is no trend in the frequency of extremely strong fronts in North America where humidity trends are, according to the IPCC AR5, close to zero. Because frontal precipitation increases with frontal strength, measured by the θ e gradient, the increase in the number of extremely strong fronts may help explain regional patterns of longer‐term trends in strong precipitation events. Key Points: The number of extremely strong front has increased over Europe, and the trend is tied to an increase in humidity (ERA‐Interim 1979–2014) No trend in the number of extremely strong fronts is identified over North America Frontal precipitation rates increase with frontal strength