Measured Constraints on Cloud Top Entrainment to Reduce Uncertainty of Nonprecipitating Stratocumulus Shortwave Radiative Forcing in the Southern Ocean
Stratocumulus cloud top entrainment has a significant effect on cloud properties, but there are few observations quantifying its impact. Using explicit 0-D parcel model simulations, initialized with below-cloud in situ measurements, and validated with in situ measurements of cloud properties, the sh...
| Published in: | Geophysical Research Letters |
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| Main Authors: | , , , |
| Format: | Text |
| Language: | unknown |
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SJSU ScholarWorks
2020
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| Subjects: | |
| Online Access: | https://scholarworks.sjsu.edu/faculty_rsca/1062 https://doi.org/10.1029/2020GL090513 https://scholarworks.sjsu.edu/context/faculty_rsca/article/2061/viewcontent/Geophysical_Research_Letters___2020___Sanchez___Measured_Constraints_on_Cloud_Top_Entrainment_to_Reduce_Uncertainty_of.pdf |
| Summary: | Stratocumulus cloud top entrainment has a significant effect on cloud properties, but there are few observations quantifying its impact. Using explicit 0-D parcel model simulations, initialized with below-cloud in situ measurements, and validated with in situ measurements of cloud properties, the shortwave cloud radiative forcing (SWCF) was reduced by up to 100 W m−2 by cloud top entrainment in the Southern Ocean. The impact of entrainment-corrected SWCF is between 2 and 20 times that of changes in the aerosol particle concentration or updraft at cloud base. The variability in entrainment-corrected SWCF accounts for up to 50 W m−2 uncertainty in estimating cloud forcing. Measurements necessary for estimating the impact of entrainment on cloud properties can be constrained from existing airborne platforms and provide a first-order approximation for cloud radiative properties of nonprecipitating stratocumulus clouds. These measurement-derived estimates of entrainment can be used to validate and improve parameterizations of entrainment in Global Climate Models. |
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