Evidence of a diurnal cycle in precipitation over the southern ocean as observed at macquarie Island

Francisco Lang, Yi Huang, Steven T. Siems, Michael J. Manton

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)


Due to a lack of observations, relatively large discrepancies exist between precipitation products over the Southern Ocean. In this manuscript, surface hourly precipitation observations from Macquarie Island (54.62° S, 158.85° E) are analysed (1998-2016) to reveal a diurnal cycle. The precipitation rate is at a maximum during night/early morning and a minimum in the afternoon at Macquarie Island station. Seasonally, the diurnal cycle is strongest in summer and negligible over winter. Such a cycle is consistent with precipitation arising from marine boundary layer clouds, suggesting that such clouds are making a substantial contribution to total precipitation over Macquarie Island and the Southern Ocean. Using twice daily upper air soundings (1995-2011), lower troposphere stability parameters show a stronger inversion at night, again consistent with precipitation arising from marine boundary layer clouds. The ERA-Interim precipitation is dominated by a 12 hourly cycle, year around, which is likely to be a consequence of the twice-daily initialisation. The implication of a diurnal cycle in boundary layer clouds over the Southern Ocean to derived A-Train satellite precipitation products is also discussed.

Original languageEnglish
Article number181
Number of pages12
Issue number2
Publication statusPublished - 1 Feb 2020


  • Diurnal cycle
  • Macquarie island
  • Marine boundary layer clouds
  • Precipitation
  • Southern ocean

Cite this