Ice microphysics and climatic temperature feedback

Ou, S. C.; Liou, Kuo‐Nan

doi:10.1016/0169-8095(94)00014-5

Cited by 89 publications

(64 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For thick clouds (type 4; Figs. 3d, i), frequencies of cloud particles are almost the same from the top to the bottom of the ice cloud layer, and the cloud particle size increases with temperature, which is consistent with Ou and Liou (1995). For very thick clouds (type 5; Figs.…”

Section: Differences In Ice Cloud Properties Over the Wp And Epsupporting

confidence: 75%

Differences in Ice Cloud Microphysical Properties between Western and Eastern Tropical Pacific Regions Derived from CloudSat and CALIPSO Measurements

Takahashi

Hayasaka

Okamoto

2016

SOLA

View full text Add to dashboard Cite

We revealed the difference in the ice cloud microphysical properties of high clouds between the western Pacific (WP) and eastern Pacific (EP) regions, based on satellite retrievals. The effective particle radius (r e ) was analyzed by using active sensors on board the CloudSat and CALIPSO satellites. We focused on ice clouds, defined as clouds with cloud top temperatures of less than 0°C. These ice clouds are classified into five types defined by the cloud optical thickness (COT). Mean cloud top heights of high cloud in WP were higher than those in EP by about 2km. The r e of optically thin clouds (0 < COT < 0.3) showed weak temperature dependency over both regions. For optically thick clouds (3 < COT), r e increases with temperature (T ). In the WP, r e at lower temperatures (T < −40°C) is larger than that in the EP, whereas in the EP, r e at higher temperatures (T > −40°C) is larger than that in the WP. The difference in r e may be caused by differences in moisture convergence and upward motion.(Citation: Takahashi, N., T. Hayasaka, and H. Okamoto, 2016: Differences in ice cloud microphysical properties between western and eastern tropical Pacific regions derived from CloudSat and CALIPSO measurements. SOLA, 12, 91−95,

show abstract

Section: Differences In Ice Cloud Properties Over the Wp And Epsupporting

confidence: 75%

Differences in Ice Cloud Microphysical Properties between Western and Eastern Tropical Pacific Regions Derived from CloudSat and CALIPSO Measurements

Takahashi

Hayasaka

Okamoto

2016

SOLA

View full text Add to dashboard Cite

show abstract

“…This approach is rooted in earlier ice microphysics observations from aircraft and attests to the fact that small and large ice crystals are related to cold and warm temperatures in cirrus cloud layers. Ou and Liou (1995) developed a parameterization equation relating cirrus temperature to a mean effective ice crystal size (D e ) based on a large number of midlatitude cirrus microphysics data presented by Heymsfield and Platt (1984). Liou et al (2008) recently developed a correlation analysis involving IWC and D e on the basis of fundamental thermodynamic principles intended for application to climate models.…”

Section: Aerosolsmentioning

confidence: 99%

Dust aerosol impact on North Africa climate: a GCM investigation of aerosol-cloud-radiation interactions using A-Train satellite data

Gu¹,

Liou²,

Jiang

et al. 2012

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. The climatic effects of dust aerosols in North Africa have been investigated using the atmospheric general circulation model (AGCM) developed at the University of California, Los Angeles (UCLA). The model includes an efficient and physically based radiation parameterization scheme developed specifically for application to clouds and aerosols. Parameterization of the effective ice particle size in association with the aerosol first indirect effect based on ice cloud and aerosol data retrieved from A-Train satellite observations have been employed in climate model simulations. Offline simulations reveal that the direct solar, IR, and net forcings by dust aerosols at the top of the atmosphere (TOA) generally increase with increasing aerosol optical depth. When the dust semi-direct effect is included with the presence of ice clouds, positive IR radiative forcing is enhanced since ice clouds trap substantial IR radiation, while the positive solar forcing with dust aerosols alone has been changed to negative values due to the strong reflection of solar radiation by clouds, indicating that cloud forcing associated with aerosol semi-direct effect could exceed direct aerosol forcing. With the aerosol first indirect effect, the net cloud forcing is generally reduced in the case for an ice water path (IWP) larger than 20 g m −2 . The magnitude of the reduction increases with IWP.AGCM simulations show that the reduced ice crystal mean effective size due to the aerosol first indirect effect results in less OLR and net solar flux at TOA over the cloudy area of the North Africa region because ice clouds with smaller size trap more IR radiation and reflect more solar radiation. The precipitation in the same area, however, increases due to the aerosol indirect effect on ice clouds, corresponding to the enhanced convection as indicated by reduced OLR. Adding the aerosol direct effect into the model simulation reduces the precipitation in the normal rainfall band over North Africa, where precipitation is shifted to the south and the northeast produced by the absorption of sunlight and the subsequent heating of the air column by dust particles. As a result, rainfall is drawn further inland to the northeast.This study represents the first attempt to quantify the climate impact of the aerosol indirect effect using a GCM in connection with A-Train satellite data. The parameterization for the aerosol first indirect effect developed in this study can be readily employed for application to other GCMs.

show abstract

“…The default ECMWF R eff (T) parameterization (based on the work of Ou and Liou [1995]) is showing the largest offset in transmissivity(+4%) compared with the observed values for the 13 days for the single column calculations. The other three parameterizations result in a better agreement where the smallest differences are given by the new R eff (H,Z) and R eff (30 mm) formulations.…”

Section: Discussionmentioning

confidence: 99%

“…The first one under consideration is the current RACMO2 parameterization adopted from a former version of the ECMWF-IFS (cy23r4). This parameterization (a revision from the work of Ou and Liou [1995]), hereafter referred to as R eff (T), is based on temperature only, with a linear transition in R eff from 30 to 60 mm between À60°and À40°C. The values are assumed to be constant outside this temperature regime (30 mm for T < À60°C and 60 mm for T > À40°C).…”

Section: Effective Radius Parameterizations For Use In Climate Modelsmentioning

confidence: 99%

Sensitivity of the shortwave radiative budget to the parameterization of ice crystal effective radius

Zadelhoff¹,

Meijgaard²,

Donovan³

et al. 2007

J. Geophys. Res.

View full text Add to dashboard Cite

[1] A new effective particle size (R eff ) parameterization for ice clouds has been formulated based on depth into cloud relative to cloud top. This parameterization has been developed based on an extensive data set of lidar and radar ice cloud retrievals. Using this parameterization within the stand-alone radiation code from the European Centre for Medium Range Weather Forecasting (cy23r4), the performance of the new parameterization is compared with the more commonly used parameterizations based on temperature and/or ice water content. An evaluation is performed on the basis of observed shortwave fluxes for 13 days with persistent ice cloud decks, with no liquid clouds beneath, over the Cabauw Experimental Site for Atmospheric Research in the Netherlands. For each of these clouds the shortwave flux is calculated after which the distribution of the differences between the observed and modeled shortwave fluxes from the combined 13 days are compared with each other. The new parameterization shows a median absolute difference of 0.7 W m À2 relative to the observations. The control parameterization based on temperature shows a median absolute difference of 15 W m À2. Within the framework of the KNMI regional climate model (RACMO2), the new parameterization yields an effective particle size versus temperature distribution very similar to the observed distributions from lidar and radar retrievals. Results from a 1-year integration indicate that the domain averaged monthly mean planetary albedo and transmissivity change by a maximum of 2.6 and 2.4%, respectively, using the new parameterization compared to the temperature-based parameterization.

show abstract

Ice microphysics and climatic temperature feedback

Cited by 89 publications

References 20 publications

Differences in Ice Cloud Microphysical Properties between Western and Eastern Tropical Pacific Regions Derived from CloudSat and CALIPSO Measurements

Differences in Ice Cloud Microphysical Properties between Western and Eastern Tropical Pacific Regions Derived from CloudSat and CALIPSO Measurements

Dust aerosol impact on North Africa climate: a GCM investigation of aerosol-cloud-radiation interactions using A-Train satellite data

Sensitivity of the shortwave radiative budget to the parameterization of ice crystal effective radius

Contact Info

Product

Resources

About