Title :

Global Statistics of Ice Microphysical and Optical Properties at Tops of Optically Thick Ice Clouds

Author(s) :

Van Diedenhoven, Bastiaan [Auteur]
Center for Climate Systems Research [New York] [CCSR]
NASA Goddard Institute for Space Studies [GISS]
Ackerman, Andrew S. [Auteur]
NASA Goddard Institute for Space Studies [GISS]
Fridlind, Ann M. [Auteur]
NASA Goddard Institute for Space Studies [GISS]
Cairns, Brian [Auteur]
NASA Goddard Institute for Space Studies [GISS]
Riedi, Jerome [Auteur]
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]

Journal title :

Journal of Geophysical Research: Atmospheres

Abbreviated title :

J. Geophys. Res.-Atmos.

Volume number :

125

Pages :

-

Publication date :

2021-03-10

ISSN :

2169-897X

English keyword(s) :

ice clouds
ice growth
microphysics
climate
optical properties

HAL domain(s) :

Planète et Univers [physics]/Océan, Atmosphère

English abstract : [en]

The sizes and shapes of ice crystals in clouds affect fundamental microphysical processes, such as sedimentation and aggregation, as well as their optical properties. The evolution of ice crystal size and shape depends on ...
Show more >The sizes and shapes of ice crystals in clouds affect fundamental microphysical processes, such as sedimentation and aggregation, as well as their optical properties. The evolution of ice crystal size and shape depends on temperature and supersaturation, as well as on other processes that may lead to various coexisting complex shapes. Here we present a global assessment of collocated size and shape characteristics and shortwave scattering properties of ice crystals at the tops of optically thick clouds inferred from space-borne multiwavelength reflectance measurements and multiangle polarimetry. The results indicate systematic covariations of ice size, shape, and distortion, as well as variations with temperature that can be plausibly related to simplified ice crystal growth theory and in situ and laboratory data. This simplicity may be attributable to the temperature dependence of cloud top ice size and shapes commonly being dominated by vapor growth at conditions similar to those at cloud top. Such a conclusion may be viewed as somewhat surprising given the expectation that ice properties at cloud top will be an integral manifestation of processes occurring at lower levels within updrafts. We also find that, contrary to commonly used models, ice scattering asymmetry parameters decrease with increasing effective radius, reducing sensitivity of cloud reflectance to particle size.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS

Collections :

• Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518

Submission date :

2024-01-16T22:16:39Z
2024-02-09T10:40:55Z