<p>Cloud free skies are rare in the trades. &#160;We analyze conditions in which cloud-free conditions prevail. &#160;For this purpose Raman water vapor measurements from the Barbados Cloud Observatory, complemented by ship-based measurements during EUREC4A are used to explore water vapor variability in the marine boundary layer. &#160; We explore the consistency of the inferred cloud base height with estimates of temperature and water vapor from the lidar signal, and examine the co-variability of these quantities. &#160;After having established the properties of these measurements, we seek to use them as well as others, to explain in what ways periods of cloud-free conditions are maintained, investigating the hypothesis that only when the wind stills is it simply sunny.</p>
Cloud Base Height and Effective Cloud Emissivity Retrieval with Ground-Based Infrared Interferometer
