Signature of cloud-base-height skewness in ARM microwave water radiometer data: implications for cloud radiative parameterizations in GCMs

Christopher A. Jeffery; Anthony B. Davis

doi:10.1117/12.482314

5 September 2002 Signature of cloud-base-height skewness in ARM microwave water radiometer data: implications for cloud radiative parameterizations in GCMs

Christopher A. Jeffery, Anthony B. Davis

Author Affiliations +

Proceedings Volume 4815, Atmospheric Radiation Measurements and Applications in Climate; (2002) https://doi.org/10.1117/12.482314
Event: International Symposium on Optical Science and Technology, 2002, Seattle, WA, United States

Abstract

The statistics of ground-based retrievals of cloud liquid water path using the microwave water radiometer (MWR) are typically assumed to be independent of the cloud's absolute position in the column. Furthermore, translational invariance implies statistical parity, i.e. invariance under reflection, of cloud-base height (z_bot) and cloud-top height distributions. This symmetry is necessarily broken, especially under conditions of high boundary-layer relative humidity for which a minimum large-scale lifting condensation level leads to the generation of a significant positive skewness in the distribution function of z_bot. We suggest that the signature of this boundary effect is visible in ARM MWR time-series collected at the TWP site. Motivated by the MWR analysis, we incorporate a minimum lifting condensation level into the analytic model of unresolved low-cloud optical variability developed by Jeffery & Austin (J. Atmos. Sci., to appear). Preliminary results indicate that the effect of cloud-base height skewness on mean oceanic low-cloud reflectivity averaged over GCM spatial scales (order 100 km) is significant.

Citation Download Citation

Christopher A. Jeffery and Anthony B. Davis "Signature of cloud-base-height skewness in ARM microwave water radiometer data: implications for cloud radiative parameterizations in GCMs", Proc. SPIE 4815, Atmospheric Radiation Measurements and Applications in Climate, (5 September 2002); https://doi.org/10.1117/12.482314

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available