Trends and Sensitivities of Low‐Cloud Cover and Top Height From Spaceborne Lidar Observations

Low clouds effectively cool the Earth by reflecting incoming solar radiation. Detecting low‐level clouds with passive satellite sensors can be ambiguous, whereas active remote sensing instruments directly measure cloud‐top height. Here, we analyze 14 years of spaceborne lidar observations to assess trends in the occurrence of low‐level clouds and their cloud‐top height. We find that spatial trend patterns in low‐level cloud cover and low‐level cloud top height are negatively correlated, that is, regions with a decrease in low‐cloud cover tend to show an increase in cloud‐top height. We find that spatial trend patterns can be well explained by sea‐surface temperature (SST) and estimated inversion strength. Low‐level clouds in climatological stratocumulus regions are particularly sensitive to changes in SST ( to in cloud cover and in cloud‐top height) and estimated inversion strength ( in cloud cover and in cloud‐top height).