Details

Autor(en) / Beteiligte

• Lang, Francisco
• Ackermann, Luis
• Huang, Yi
• Truong, Son C. H
• Siems, Steven T
• Manton, Michael J

Titel

A climatology of open and closed mesoscale cellular convection over the Southern Ocean derived from Himawari-8 observations

Ist Teil von

• Atmospheric chemistry and physics, 2022-02, Vol.22 (3), p.2135-2152

Ort / Verlag

Katlenburg-Lindau: Copernicus GmbH

Erscheinungsjahr

2022

Link zum Volltext

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• Marine atmospheric boundary layer clouds cover vast areas of the Southern Ocean (SO), where they are commonly organized into mesoscale cellular convection (MCC). Using 3 years of Himawari-8 geostationary satellite observations, open and closed MCC structures are identified using a hybrid convolutional neural network. The results of the climatology show that open MCC clouds are roughly uniformly distributed over the SO storm track across midlatitudes, while closed MCC clouds are most predominant in the southeast Indian Ocean, with a second maximum along the storm track. The ocean polar front, derived from ECMWF-ERA5 sea surface temperature gradients, is found to be aligned with the southern boundaries for both MCC types. Along the storm track, both closed and open MCCs are commonly located in post-frontal, cold air masses. The hourly classification of closed MCC reveals a pronounced daily cycle, with a peak occurring late night/early morning. Seasonally, the diurnal cycle of closed MCC is most intense during the summer months (December–February; DJF). Conversely, almost no diurnal cycle is evident for open MCC.