Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 5.414
IF 5-year value: 5.958
IF 5-year
CiteScore value: 9.7
SNIP value: 1.517
IPP value: 5.61
SJR value: 2.601
Scimago H <br class='widget-line-break'>index value: 191
Scimago H
h5-index value: 89

  17 Aug 2020

17 Aug 2020

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

Processes contributing to Arctic cloud dissipation and formation events that bookend clear sky periods

Joseph Sedlar1,2, Adele Igel3, and Hagen Telg1,2 Joseph Sedlar et al.
  • 1Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA
  • 2NOAA Global Monitoring Laboratory, Boulder, CO, USA
  • 3University of California Davis, USA

Abstract. The Arctic is predominantly cloudy with intermittent clear sky periods. These clear periods have profound impacts on the surface energy budget and lower atmospheric stratification, connected to a lack of downwelling longwave radiation in the absence of cloud. Despite the importance of clear sky conditions, an understanding of the atmospheric processes leading to low-level cloud dissipation and formation events is relatively limited. A strict definition to identify clear periods at Utqiagvik (formerly Barrow), Alaska, during a five-year period (2014–2018) is developed. A suite of remote sensing and in situ instrumentation from the high-latitude observatory are analysed; we focus on comparing and contrasting atmospheric properties during low-level cloud dissipation and formation events to understand the processes controlling clear sky periods. Vertical profiles of lidar backscatter suggest that aerosol presence across the lower atmosphere is relatively invariant around the clear period bookends, which suggests that a sparsity of aerosol is not frequently a cause for cloud dissipation. Further meteorological analysis indicates two active processes ongoing that appear to support the formation of low clouds after a clear sky period and have a link to surface aerosol concentrations; namely, horizontal advection which was dominant in winter and early spring and quiescent air mass modification which was dominant in the summer. During summer, the dominant mode of cloud formation is a low cloud/fog layer developing near the surface. This low cloud formation is driven largely by air mass modification and pooling of aerosol particles near the surface under lower-atmosphere stratification.

Joseph Sedlar et al.

Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for authors/editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Joseph Sedlar et al.

Joseph Sedlar et al.


Total article views: 228 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
162 61 5 228 4 6
  • HTML: 162
  • PDF: 61
  • XML: 5
  • Total: 228
  • BibTeX: 4
  • EndNote: 6
Views and downloads (calculated since 17 Aug 2020)
Cumulative views and downloads (calculated since 17 Aug 2020)

Viewed (geographical distribution)

Total article views: 238 (including HTML, PDF, and XML) Thereof 236 with geography defined and 2 with unknown origin.
Country # Views %
  • 1
Latest update: 27 Jan 2021
Publications Copernicus