Case: 25 January 2018

Summary

Open-cellular cumulus that transitioned to a drizzling stratocumulus deck for an extended period

Description

This was a multi-day event that began on January 25th with open cells that transitioned to a closed stratocumulus deck as the event progressed. This event was collected during the ACE-ENA campaign and included a G-1 aircraft mission. The boundary-layer winds associated with the event were from the northeast. The widespread cloud deck sampled during the second-half of this event features drizzle; ARM profiling observations also indicated signatures of precipitation that reached the surface at various times. There were upper-level clouds observed over the northern part of the LASSO modeling domain owing to a stalled anticyclone near the Azores. Inversion height at approximately 1.6 km AGL.

Available assets

Standard ARM profiling assets, SEVIRI. ACE-ENA campaign day, which includes four radiosonde launches, SACR, XSAPR, RLPROF-FEX, ARM AAF Gulfstream-1 (G-1)

Critical period: 11:00-onwards

The early open-cell cloud characteristics have transitioned to closed-cell behaviors

Figure 12 True-color afternoon MODIS Aqua image with overlaid LES domains. The image area corresponds to the 5° region sampled for the larger forcing option. The yellow and orange boxes correspond to the sizes of the 25 km and 102 km LES domains, respectively.