A Climatology of South Ecuador: with Special Focus on the Major Andean Climate Divide

This work is the first in-depth study of the climate in the Andes of South Ecuador and North Peru. The data sets used are from own measurements, from the national weather stations and NCEP Reanalysis data. A particular feature of this work is the innovative graphical methods of presenting both measured and model data. The Andes of South Ecuador pose a significant, perpendicular barrier to a quasi-permanent easterly mid-level jet stream. Nearly incessant orographic uplift and interception of moisture at the eastern slopes makes the highest ridge of the Andes, the Cordillera Real, a true climate divide that separates (per) humid climates from arid and semiarid climates. The outstanding topographic and climate setup produces a row of surprising weather extremes. Wind speed reaches mean monthly values of up to 15 m/s, mean daily speed of up to 24 m/s and gusts have reached >28 m/s (10 Bft). Advective and wind-enhanced rainfall amounts to >6,000 mm/y in the summit regions. Within 30 km, in the rain shadow, these totals are contrasted by barely 300 mm/y. Very clear skies, cloud radiative effects and the high sun position boost global irradiance to absolute magnitudes of over 1800 W/m2!