Date SINGLE-COLUMN MODEL SIMULATIONS

3 We evaluate the ability of a typical cloud parameterization from a global model (CCM3 from NCAR) to simulate the Arctic cloudiness and longwave radiative fluxes during wintertime. Simulations are conducted with a Single-Column Model (SCM) forced with observations and reanalysis data from the Surfa...

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Bibliographic Details
Main Authors: Cécile Hannay, Of Arctic, Cloudiness, Surface Radiative Fluxes, Licenciée En Sciences Physiques
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2001
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.533.621
http://www2.gi.alaska.edu/~bhatt/proffexp.docs/Hannay.thesis.pdf
Description
Summary:3 We evaluate the ability of a typical cloud parameterization from a global model (CCM3 from NCAR) to simulate the Arctic cloudiness and longwave radiative fluxes during wintertime. Simulations are conducted with a Single-Column Model (SCM) forced with observations and reanalysis data from the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment. Typically, the SCM overestimates the Arctic cloud fraction and the downwelling longwave flux. Moreover, the SCM does not capture accurately the temperature and moisture profiles, and the surface flux fields. Relaxing temperature and moisture profiles to observed values dramatically improves the simulations. This suggests that the cloud parameterization of CCM3 is suitable for Arctic clouds, as long as the temperature and moisture fields are captured correctly. Sensitivities studies show that the cloud fraction is not very sensitive to cloud type, ice effective radius, ice liquid ratio amount and uncertainty of the advective forcing. 4