Signals of climate variability/change in surface supply of high-mountain watersheds Case study: Claro River high mountain basin, Los Nevados Natural Park, Andean Central Mountain Range

Chapter 1: Lifting Level February 2009

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Signals of climate variability/change in surface water supply of high-mountain watersheds Case study: Claro River high mountain basin, Los Nevados Natural Park, Andean Central Mountain Range

Contract 7147577 – The World Bank Group

Daniel Ruiz Carrascal Línea de Investigación en Hidroclimatología Grupo de Investigación ‘Gestión del Ambiente para el Bienestar Social - GABiS’ Escuela de Ingeniería de Antioquia Calle 25Sur No. 42-73, Envigado, Antioquia, Colombia Phone: (57-4) 339-3200; Fax: (57-4) 331 7851; E-mail: [email protected]

Chapter 1: Lifting Condensation Level February 2009

2 Escuela de Ingeniería de Antioquia

Executive, academia and research administration

President

Carlos Felipe Londoño Álvarez

Secretary

Olga Lucía Ocampo Toro

Dean of Engineering

Carlos Rodríguez Lalinde

Director of Research Activities

Nathalia Vélez López de Mesa

Director of Research Group ‘GABiS’

Maria del Pilar Arroyave Maya

Director of Environmental Engineering Program

Santiago Jaramillo Jaramillo

Research Team

Principal Investigator

Daniel Ruiz Carrascal

Co-PI

Maria del Pilar Arroyave Maya Adriana María Molina Giraldo Juan Fernando Barros Martínez

Research Assistants

Maria Elena Gutiérrez Lagoueyte Paula Andrea Zapata Jaramillo

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Table of content

1.1 Brief description of circulation patterns 8

1.2 Lifting Condensation Levels estimates 9 1.2.1 1950-inferred and 2050-predicted LCLs 12 1.2.2 Static stability 15

1.3 Instruments 15

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Tables

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1.1 Data gathered at the T/H Data Loggers over the historical period December, 2008-January, 2009 17

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Figures

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Vertical profiles of mean annual , minimum annual temperature, and annual point 1.1 10 for the mainstream of the Claro River under historical conditions Spatial distribution of the historical w -w difference for the selected spatial domain (04 °25’N- 1.2 s 10 05 °15’N and 75 °00’W-76 °00’W) Spatial distribution of the estimated Lifting Condensation Level for historical mean and maximum 1.3 11 annual 1.4 Historical, 1950-inferred and 2050-predicted near-surface lapse rates 12 Estimated 1950- and 2050-altitudinal changes in the distribution of the mean Lifting Condensation 1.5 14 Level Estimated regions of static instability, conditional instability, and static stability in the area of the 1.6 15 Claro River’s watershed 1.7 Temperature/Relative Data Loggers installed along the defined altitudinal transect 16 Temperature/Relative Humidity Data Logger installed in the surroundings of the site ‘Salto de la 1.8 Cueva’ (3,790 m), GPS mark ID 029, and diurnal cycles of ambient temperature and relative 16 humidity for the 5-day period 12/23/2008-12/27/2008 Time series of ambient temperatures and relative humidity values collected at the installed T/H 1.9 17 sensors during the 5-day period 12/23/2008-12/27/2008 Ambient temperatures gathered at the installed T/H sensors and observed over the period from 1.10 18 December 23, 2008 through January 30, 2009 (39-day historical period)

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Chapter 1 Lifting Condensation Level

Thermodynamic and dynamic atmospheric processes play a significant role in the integrity and functioning of Andean high- ecosystems. This chapter describes our analyses of the potential changes in atmospheric stability and lifting condensation levels (LCLs) in the area of the Claro River’s high-altitude basin and its surroundings. The first section provides a brief description of circulation patterns on both regional and local spatial scales. The second section presents some estimates of the LCL for historical and predicted mean annual temperatures and maximum temperatures during the warmest days. A discussion on near-surface environmental lapse rates for 1950-inferred and 2050-predicted temperature conditions is included. Likely upward shifts in LCLs in the spatial domain (04 °25’N- 05 °15’N and 75 °00’W-76 °00’W) and along the mainstream of the Claro River’s watershed are also estimated. Finally, regions of static instability, conditional instability, and static stability in the area of the Claro River’s watershed are presented for historical climatic conditions. Section 1.3 describes the Temperature/Relative Humidity sensors that have been deployed (up to date) to monitor potential changes in atmospheric stability and the altitude of the LCLs under future climatic conditions. Diurnal cycles of ambient temperatures and relative humidity values observed over recent periods are presented. Finally, various near-surface environmental lapse rates observed in the altitudinal range [3,600 m–4,500 m] are compared with dry and moist (saturated) adiabatic lapse rates.

7 1.1. Brief description of circulation patterns 1

Regional scale : in Colombia, two large rivers (the Cauca River and the Grande de la Magdalena River) divide the Andes Cordillera into three large mountain ranges: the Occidental (Western), the Central and the Oriental (Eastern) cordilleras. These three mountain branches and their two inter-Andean valleys constitute the so-called Colombian Andean region. The hydro-climatology of this central region is strongly influenced by the behavior of four climate features: the northeasterly trade , the easterlies, the Chocó low-level jet-CLLJ (Poveda and Mesa, 2000; Vernekar et al ., 2003), and the low-level jet to the east of the Cordillera Oriental (Vernekar et al ., 2003). The dynamics and interactions between these climate features and the orography of the Andean mountain ranges produce detailed regional circulation patterns and complex local scale motions.

In the Colombian central region, the northeasterly trade winds become current valleys that blow from north to south along the inter-Andean corridors. They are felt at lower on the flood plains of the Cauca and Magdalena rivers and along the inter-Andean foothills of the high mountain ranges. The easterlies, in turn, are only felt at the summits of the highest Andean peaks (4,800-5,400 m). At these altitudes they have such strong winds that they shape the upper features of local circulation motions. The Chocó jet, on the other hand, occurs at lower levels (from the surface to almost 750 hPa) to the west of the northern Cordillera Occidental. The CLLJ brings moisture from the west Caribbean Sea, the Gulf of Panama and the Eastern Tropical Pacific into Colombia, creating an area of moisture convergence along the Pacific Coast. Finally, the jet to the east of the Cordillera Oriental also occurs at lower levels (from the surface to almost 700 hPa). This jet brings warm moist air from the Tropical Atlantic Ocean into Colombian inlands and creates a zone of moisture convergence over the northern part of the Amazon basin and the eastern foothills of the Cordillera Oriental.

The low-level jets exhibit marked variability on inter-annual, intra-annual, and even diurnal timescales. As the intensity of the CLLJ, in particular, is driven by the difference between sea surface temperatures in the Colombian Tropical Pacific Ocean and in El Nino 1+2 region, its strength is dominated by the El Nino–Southern Oscillation (ENSO) cycle. According to Vernekar et al . (2003), the CLLJ tends to be weaker in the warm phase of ENS