Preprints
https://doi.org/10.5194/acp-2021-478
https://doi.org/10.5194/acp-2021-478

  15 Jun 2021

15 Jun 2021

Review status: this preprint is currently under review for the journal ACP.

Foehn effect during easterly flow over Svalbard

Anna A. Shestakova1, Dmitry G. Chechin1, Christof Lüpkes2, Jörg Hartmann2, and Marion Maturilli2 Anna A. Shestakova et al.
  • 1Air-Sea Interaction Laboratory, A.M. Obukhov Institute of Atmospheric Physics of the Russian Academy of Sciences, Moscow, 119017, Russian Federation
  • 2Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven (Potsdam), Germany

Abstract. This article presents a comprehensive analysis of the foehn episode which occurred over Svalbard on 30–31 May 2017. This episode is well documented by multiplatform measurements carried out during the ACLOUD/PASCAL campaigns. Both orographic wind modification and foehn warming are considered here. The latter is found to be primarily produced by the isentropic drawdown, which is evident from observations and mesoscale numerical modelling. The structure of the observed foehn warming was in many aspects very similar to that for foehns over the Antarctic Peninsula. In particular, it is found that the warming was proportional to the height of the mountain ridges and propagated far downstream. Also, a strong spatial heterogeneity of the foehn warming was observed with a clear cold footprint associated with gap flows along the mountain valleys and fjords. On the downstream side, a shallow stably-stratified boundary layer below a well-mixed layer formed over the snow-covered land and cold open water. The foehn warming downwind Svalbard strengthened the north-south horizontal temperature gradient across the ice edge near the northern tip of Svalbard. This suggests that the associated baroclinicity might have strengthened the observed northern tip jet. Positive daytime radiative budget on the surface, increased by the foehn clearance, along with the downward sensible heat flux provoked an accelerated snowmelt in the mountain valleys in Ny-Alesund and Adventdalen, which suggests a potentially large effect of the frequently observed Svalbard foehns on the snow-cover and the glacier heat and mass balance.

Anna A. Shestakova et al.

Status: open (until 25 Aug 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Anna A. Shestakova et al.

Anna A. Shestakova et al.

Viewed

Total article views: 221 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
171 45 5 221 2 1
  • HTML: 171
  • PDF: 45
  • XML: 5
  • Total: 221
  • BibTeX: 2
  • EndNote: 1
Views and downloads (calculated since 15 Jun 2021)
Cumulative views and downloads (calculated since 15 Jun 2021)

Viewed (geographical distribution)

Total article views: 204 (including HTML, PDF, and XML) Thereof 204 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 28 Jul 2021
Download
Short summary
This article presents a comprehensive analysis of the easterly orographic wind episode which occurred over Svalbard on 30–31 May 2017. This wind caused significant temperature rise on the lee side of the mountains and greatly intensified the snowmelt. This episode was investigated on the basis of measurements collected during the ACLOUD/PASCAL field campaigns with the help of numerical modelling.
Altmetrics