Details:

Journal Title:
Journal of Geophysical Research: Atmospheres
Personal Author:
Naud, Catherine M. ; Booth, James F. ; Lamer, Katia ; Marchand, Roger ; Protat, Alain ; ... More +
Naud, Catherine M. ; Booth, James F. ; Lamer, Katia ; Marchand, Roger ; Protat, Alain ; McFarquhar, Greg M. Less -
NOAA Program & Office:
CIMMS (Cooperative Institute for Mesoscale Meteorological Studies)
Description:
Focusing on conditions of subsidence when low clouds are present, ground-based observations in both the North Atlantic and the Southern Ocean reveal strong relationships between cloud boundary (base and top heights) and different measures of lower tropospheric instability. The difference in potential temperature between the surface and 800 hPa (a metric called M) provides a stronger relationship than measures of inversion strength such as the lower tropospheric stability and estimated inversion strength. This is because (1) inversion strength itself does not correlate well with cloud boundaries, and (2) M contains information that appears important for cloud boundaries. These include the surface forcing through the use of sea surface rather than near-surface air temperature and an upper level close to the real cloud top. These results expand upon previous work on the importance of M as a predictor of cloud morphology. However, important differences are found in low-cloud conditions for the North Atlantic as compared to the Southern Ocean (for a given value of M): stronger inversions, deeper boundary layers, and much larger sea level pressures. Therefore, the relationship between cloud boundaries and M differs between the two regions. A general circulation model provides similar relationships as observed between M and both cloud top height and temperature but tends to place clouds higher and at colder temperatures than observed for a given M. This might cause issues with the representation of precipitation, cloud cover and radiation in the Southern Ocean.
Keywords:
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Boundary Layer Stability
CAM6
Clouds

Source:
Journal of Geophysical Research: Atmospheres, 125, e2020JD032465
DOI:
https://doi.org/10.1029/2020JD032465
Document Type:
Journal Article
Place as Subject:
Southern Ocean
Rights Information:
Other
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:71837486bad72894d25b1aa9173fad7843c8d34a7cb22f7638ff130f82954bf5
File Type:

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