Researchers from Reading have identified supercooled water layers in Chilbolton data. They form in distinct layers several hundred metres thick. The layers provide a strong signal for lidar, but because of the small droplet size, are undetected by radar when ice is present. However, they will be much more important in determining the radiative properties of the cloud than any ice present. They will also impact on glaciation and precipitation processes.
Currently, atmospheric forecast and climate models assume a simple ratio between ice and liquid water content, but if supercooled water layers are common, there is a need to improve their representation in models.
Comparing data from the IR lidar ceilometer and 94 GHz
radar to detect supercooled layers in cloud.