The radar tropopause at 78°N, 16°E: Characteristics of diurnal variation. Issue 12 (28th June 2013)

• Record Type: Journal Article
• Authors: Hall, C. M.
• Is Part Of: Journal of geophysical research. Volume 118:Issue 12(2013:Dec.)
• Page Start: 6354
• Page End: 6359
• Publication Date: 2013-06-28
• Subjects: tropopause -- diurnal variation -- Arctic; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/jgrd.50560
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract : [1] A continuous 5 year time series of tropopause altitude made by the SOUSY VHF radar on Svalbard (78°N, 16°E) is examined for diurnal variation. The data have a nominal time resolution of 1 h, allowing for investigation of intraday timescales not normally possible using radiosonde observations. Periodicities identified in tropopause altitude are found to vary with season. Surface air temperature measurements naturally exhibit diurnal variations which depend on season: however, it is demonstrated that, using a simple scenario of constant adiabatic lapse rate in the troposphere, the tropopause altitude variation that might be anticipated from that of the surface air temperature is not in agreement with the radar observation. Of several mechanisms that could be postulated for this discrepancy, it is demonstrated that a likely candidate is intraday top‐down forcing from the stratosphere. Key Points: Seasonal Intra‐day variability of arctic tropopause altitude is presented Both troposphere and stratosphere forcing control tropopause diurnal timescales These results are unique for such high latitude.