TY  - JOUR
AB  - Water droplets in some clouds can supercool to temperatures where homogeneous ice nucleation becomes the dominant freezing mechanism. In many cloud resolving and mesoscale models, it is assumed that homogeneous ice nucleation in water droplets only occurs below some threshold temperature typically set at -40 degrees C. However, laboratory measurements show that there is a finite rate of nucleation at warmer temperatures. In this study we use a parcel model with detailed microphysics to show that cloud properties can be sensitive to homogeneous ice nucleation as warm as -30 degrees C. Thus, homogeneous ice nucleation may be more important for cloud development, precipitation rates, and key cloud radiative parameters than is often assumed. Furthermore, we show that cloud development is particularly sensitive to the temperature dependence of the nucleation rate. In order to better constrain the parameterization of homogeneous ice nucleation laboratory measurements are needed at both high (>-35 degrees C) and low (<-38 degrees C) temperatures.
DA  - 2015
DO  - 10.1002/2014GL062729
KW  - freezing
KW  - droplet
KW  - cloud glaciation
KW  - homogeneous nucleation
KW  - ice nucleation
KW  - mixed-phase clouds
KW  - cloud ice
LA  - eng
IS  - 5
M2  - 1599
PY  - 2015
SN  - 0094-8276
SP  - 1599-1605
T2  - Geophysical Research Letters
TI  - Sensitivity of liquid clouds to homogenous freezing parameterizations
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-27335508
Y2  - 2024-12-25T19:36:14
ER  -