Changes of the 0°C isotherm and the equilibrium line altitude in central Chile during the last quarter of the 20th century / Changements de l'isotherme 0°C et de la ligne d'équilibre des neiges dans le Chili central durant le dernier quart du 20ème siècle
2005; Taylor & Francis; Volume: 50; Issue: 6 Linguagem: Inglês
10.1623/hysj.2005.50.6.933
ISSN2150-3435
AutoresJorge Carrasco, Gino Casassa, Juan Quintana,
Tópico(s)Geology and Paleoclimatology Research
ResumoAbstract An overall retreat of glaciers has been observed in the Andes of central Chile during the last ~100 years. Precipitation is mainly of frontal origin and concentrates in winter months. Analysis of precipitation data shows a decrease until 1976, an increase thereafter north of 34°S and a decrease south of 34°S, but overall no significant trends during the last quarter of the 20th century. Analysis of radiosonde data of central Chile shows mid-tropospheric warming with an elevation increase of the 0°C isotherm of 122 ± 8 m and 200 ± 6 m in winter and summer, respectively, during the 27-year period between 1975 and 2001. The results point to a snowline elevation increase in the region during the last quarter of the 20th century and a concurrent rise of the equilibrium line altitude (ELA) and suggest that mid-troposphere warming is the main cause for glacier retreat in central Chile.
Referência(s)