Measurements of Cloud Radiative Effect across the Southern Ocean (43° S–79° S, 63° E–158° E)

The surface radiation environment over the Southern Ocean within the region bound by 42.8° S to 78.7° S and 62.6° E to 157.7° W is summarised for three austral summers. This is done using ship-based measurements with the combination of downwelling radiation sensors and a cloud imager. We focus on ch...

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Bibliographic Details
Published in:Atmosphere
Main Authors: Haoran Wang, Andrew R. Klekociuk, W. John R. French, Simon P. Alexander, Tom A. Warner
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2020
Subjects:
Online Access:https://doi.org/10.3390/atmos11090949
https://doaj.org/article/f5a1451584824038b176f1bbe34f9736
Description
Summary:The surface radiation environment over the Southern Ocean within the region bound by 42.8° S to 78.7° S and 62.6° E to 157.7° W is summarised for three austral summers. This is done using ship-based measurements with the combination of downwelling radiation sensors and a cloud imager. We focus on characterising the cloud radiative effect (CRE) under a variety of conditions, comparing observations in the open ocean with those in the sea ice zone. For comparison with our observed data, we obtained surface data from the European Centre for Medium-Range Weather Forecasts fifth reanalysis (ERA5). We found that the daily average cloud fraction was slightly lower in ERA5 compared with the observations (0.71 and 0.75, respectively). ERA5 also showed positive biases in the shortwave radiation effect and a negative bias in the longwave radiation effect. The observed mean surface CRE of −164 ± 100 Wm −2 was more negative than the mean surface CRE for ERA5 of −101 W m −2 .