27 Oct 2021 Lake Tahoe: US
- Drought fueled by climate change has dropped Lake Tahoe in the US below its natural rim and halted flows into the Truckee River.
- It is an historically cyclical event that’s occurring sooner and more often than it used to.
About:
- Lake Tahoe is the largest alpine lake in North America, and the second deepest lake in the US, with Crater Lake in Oregon being the deepest in the US.
- Alpine lakes are lakes or reservoirs at high altitudes, usually over above sea level or above the tree line.
- Note: Great Lakes, chain of deep freshwater lakes in east-central North America comprising Lakes Superior, Michigan, Huron, Erie, and Ontario. Except for Lake Michigan, the lakes provide a natural border between Canada and the United States.
Impact of Climate Change on Lakes:
Less Ice Cover:
- Lakes are experiencing less ice cover, with more than 1,00,000 lakes at risk of having ice-free winters if air temperatures increase by 4 °C.
Increasing LSWT:
- Lake Surface Water Temperatures have increased worldwide, which is similar to or in excess of air temperature trends.
Increase in Evaporation rate:
- Global annual mean lake evaporation rates are forecast to increase 16% by 2100, with regional variations dependent on factors such as ice cover, stratification, wind speed and solar radiation.
- Lake stratification is the tendency of lakes to form separate and distinct thermal layers during warm weather.
Affecting Lake Water Storage:
- Global lake water storage is sensitive to climate change, but with substantial regional variability, and the magnitude of future changes in lake water storage remains uncertain.
yojna ias daily current affairs 27 Oct 2021
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