CR 30:133-147 (2006)  -  doi:10.3354/cr030133

ABSTRACT: We used a 3 yr data set of NOAA-AVHRR (Advanced Very High Resolution Radiometer) imagery to investigate cloud frequency, cloud-top height and cloud liquid water path for the Ecuadorean area, with special reference to a specific region in the Andes of southern Ecuador. In general, the seasonal cycle of cloudiness is significantly correlated to the spatial occurrence of the rainy seasons. However, we found that the complex topography of the Andes with dynamic effects at the windward and lee sides, as well as thermal breeze-systems, cause a specific spatial structure of cloud frequency and cloud properties. For instance, the eastern Andean slopes are mainly affected by a strong dynamic barrage effect of the easterlies, where a line of high cloud frequency occurs in the area of the Andes-occurring system (AOS) rain band. Average cloud-top height reveals a clear division between the Pacific area west of the western Cordillera chain, characterised by lower and more stratiform clouds, and the eastern parts of the country where an increase in average cloud-top height towards the Amazon indicates an intensification of convective cloud formation processes. This corresponds with the higher amounts of cloud liquid path over the Amazon, which illustrates that the cloud water cycle is more intensive in comparison to the Ecuadorian coastal plains.

KEY WORDS: Ecuador · Clouds · NOAA-AVHRR