Understanding the factors controlling on low cloud over Southeastern Atlantic: ORACLES case study

Abstract:

Previous studies showed that the stratocumulus tends to be positively associated with low-level tropospheric stability (LTS), but the relationship does not hold when other factors are at play. The various correlation between stratocumulus and LTS during different synoptic conditions suggest that variations in atmospheric circulation play a large role in modulating this low-level, boundary layer cloud amount.

In this talk, we will present the potential meteorological impacts on low cloud over the Southeast Atlantic, focusing on a NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) case study. We will show how the mid-latitude circulation, low-level jet, subtropical St. Helena High, boundary layer height (BLH), and other meteorological conditions can disrupt the simple relation. The non-local effect of the sea surface temperature (SST) on the moisture transport (using Integrated Vapor Transport (IVT)), and its potential impact on stratocumulus will also be discussed.