Sky thermal imaging using a ground-based camera

The evolution and properties of cloud cover will be explored in a unique way by using a thermal camera. Although the increase in downward long-wave forcing with increased cloud cover has been established, the expected linearity of this relationship has not been observed Aim 1: To measure cloud cover day and night. We will develop further a novel way of inferring cloud cover from thermal imaging during day and night.Validation against ceilometer derived cloud cover will be made. Aim 2: To retrieve cloud longwave forcing. Cloud longwave forcing will be derived directly from the image by simultaneously subtracting clear sky and cloud fluxes.