Hydro-climatic variability over the Andes of Colombia associated with ENSO: a review of climatic processes and their impact on one of the Earth’s most important biodiversity hotspots

• Published in: Climate dynamics Vol. 36; no. 11-12; pp. 2233 - 2249
• Main Authors: Poveda, Germán, Álvarez, Diana M., Rueda, Óscar A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2011; Springer; Springer Nature B.V
• Subjects: Aquatic resources; Biodiversity; Biological diversity; Climate science; Climatology; Climatology. Bioclimatology. Climate change; Earth; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Ecosystems; Exact sciences and technology; External geophysics; Geophysics/Geodesy; Hurricanes; Hydrology; Marine; Meteorology; Oceanography; Rain and rainfall; Soil moisture; Southern oscillation; Water balance (Hydrology); Water in the atmosphere (humidity, clouds, evaporation, precipitation); South America; Colombia; Andes; ASW, Colombia; South America, Andes Mts; Hydro-climatology; Colombia; Andes; Biodiversity; ENSO; Tropics; Dynamical climatology; El Nino; Southern oscillation; Regional scope; tropical zone; Observation data; climate variability; species diversity; Hydroclimatology; La Nina
• ISSN: 0930-7575; 1432-0894
• DOI: 10.1007/s00382-010-0931-y

The hydro-climatic variability of the Colombian Andes associated with El Niño–Southern Oscillation (ENSO) is reviewed using records of rainfall, river discharges, soil moisture, and a vegetation index (NDVI) as a surrogate for evapotranspiration. Anomalies in the components of the surface water balance during both phases of ENSO are quantified in terms of their sign, timing, and magnitude. During El Niño (La Niña), the region experiences negative (positive) anomalies in rainfall, river discharges (average and extremes), soil moisture, and NDVI. ENSO’s effects are phase-locked to the seasonal cycle, being stronger during December–February, and weaker during March–May. Besides, rainfall and river discharges anomalies show that the ENSO signal exhibits a westerly wave-like propagation, being stronger (weaker) and earlier (later) over the western (eastern) Andes. Soil moisture anomalies are land-cover type dependant, but overall they are enhanced by ENSO, showing very low values during El Niño (mainly during dry seasons), but saturation values during La Niña. A suite of large-scale and regional mechanisms cooperating at the ocean–atmosphere–land system are reviewed to explaining the identified hydro-climatic anomalies. This review contributes to an understanding of the hydro-climatic framework of a region identified as the most critical hotspot for biodiversity on Earth, and constitutes a wake-up call for scientists and policy-makers alike, to take actions and mobilize resources and minds to prevent the further destruction of the region’s valuable hydrologic and biodiversity resources and ecosystems. It also sheds lights towards the implementation of strategies and adaptation plans to coping with threats from global environmental change.