Get 20M+ Full-Text Papers For Less Than $1.50/day. Subscribe now for You or Your Team.

Learn More →

Impact of Secular Climate Change on the Thermal Structure of a Large Temperate Central European Lake

Impact of Secular Climate Change on the Thermal Structure of a Large Temperate Central European Lake Strong climate-related secular trends are apparent in a 52-yr long (1947–1998) uninterrupted series of monthly temperature profiles fromLake Zurich, a large, deep (136 m), temperate lake on the Swiss Plateau. Decadal mean water temperatures have undergone a secular increase at all depths, reflecting the high degree of regional warming that occurred in the European Alpine area during the 20th century. From the 1950s to the 1990s, high warming rates (∼ 0.24 K per decade) in the uppermost 20 m of the lake (i.e., the epi/metalimnion) combined with lower warming rates (∼ 0.13 K per decade) below 20 m (i.e., in the hypolimnion), have resulted in a20% increase in thermal stability and a consequent extension of 2–3 weeksin the stratification period. In common with many other parts of the world, 20th-century climate change on the Swiss Plateau has involved a steep secular increase in daily minimum (nighttime) air temperatures, but not in daily maximum (daytime) air temperatures. With respect to both secular change and decadal-scale variability, the temporal structure of the temperature of the surface mixed layer of Lake Zurich faithfully reflects that of the regional daily minimum air temperature, but not that of the daily maximum. The processes responsible for longer-term changes in the temperature structure of the lake therefore act during the night, presumably by suppressing nighttime convective cooling of the surface mixed layer. Application of a one-box heat exchange model suggests that the observed secular changes in thermal structure are due to shifts in the nighttime rate of emission of infrared radiation from the atmosphere and in the nighttime rates of latent and sensible heat exchange at the air-water interface. The increase in hypolimnetic temperatures is mainly a result of the increased prevalence of warm winters in Europe. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Climatic Change Springer Journals

Impact of Secular Climate Change on the Thermal Structure of a Large Temperate Central European Lake

Climatic Change , Volume 57 (2) – Oct 10, 2004

Loading next page...
 
/lp/springer-journals/impact-of-secular-climate-change-on-the-thermal-structure-of-a-large-ov1bBg7P75

References (68)

Publisher
Springer Journals
Copyright
Copyright © 2003 by Kluwer Academic Publishers
Subject
Earth Sciences; Atmospheric Sciences; Climate Change/Climate Change Impacts
ISSN
0165-0009
eISSN
1573-1480
DOI
10.1023/A:1022119503144
Publisher site
See Article on Publisher Site

Abstract

Strong climate-related secular trends are apparent in a 52-yr long (1947–1998) uninterrupted series of monthly temperature profiles fromLake Zurich, a large, deep (136 m), temperate lake on the Swiss Plateau. Decadal mean water temperatures have undergone a secular increase at all depths, reflecting the high degree of regional warming that occurred in the European Alpine area during the 20th century. From the 1950s to the 1990s, high warming rates (∼ 0.24 K per decade) in the uppermost 20 m of the lake (i.e., the epi/metalimnion) combined with lower warming rates (∼ 0.13 K per decade) below 20 m (i.e., in the hypolimnion), have resulted in a20% increase in thermal stability and a consequent extension of 2–3 weeksin the stratification period. In common with many other parts of the world, 20th-century climate change on the Swiss Plateau has involved a steep secular increase in daily minimum (nighttime) air temperatures, but not in daily maximum (daytime) air temperatures. With respect to both secular change and decadal-scale variability, the temporal structure of the temperature of the surface mixed layer of Lake Zurich faithfully reflects that of the regional daily minimum air temperature, but not that of the daily maximum. The processes responsible for longer-term changes in the temperature structure of the lake therefore act during the night, presumably by suppressing nighttime convective cooling of the surface mixed layer. Application of a one-box heat exchange model suggests that the observed secular changes in thermal structure are due to shifts in the nighttime rate of emission of infrared radiation from the atmosphere and in the nighttime rates of latent and sensible heat exchange at the air-water interface. The increase in hypolimnetic temperatures is mainly a result of the increased prevalence of warm winters in Europe.

Journal

Climatic ChangeSpringer Journals

Published: Oct 10, 2004

There are no references for this article.