Climatic change: new scientific study

Data were found by a scientific team and show that the climatic change has consequences on the lakes located in the hot and cold areas of the earth. These results can be read in the Geophysical Research Letters revue.

The scientists postulated that higher temperatures could trigger changes in nutrient exchanges and turnover in the water. The rising temperatures and other climatic elements can seriously influence the winter circulation in a number of situations. These changes lead to lower levels of oxygen, which in turn lead to an increase in the quantity of nutrients in deep waters.

The researchers from Helmholtz Centre for Environmental Research (UFZ) in Germany, Japan’s Hokkaido University, the Hokkaido Institute of Environmental Sciences and Kagoshima University compared up-to-date measurements with measurements taken 70 years ago.

Measurements taken between 2005 and 2007 in deep caldera lakes of Japan offer data about the distribution of dissolved nutrients in the water, the researchers explained, adding that using this chain of lakes for their research was great because the lakes cover a climate gradient that extends from the south of Japan to Hokkaido Island in the north. Also, oxygen and nutrient exchange between the lakes’ deep waters and surface waters is nearly completely controlled by the differences in temperatures.

The data obtained in the study offer researchers general information about circulation under changeable climatic conditions that will be valid for lakes outside the research area, the team said.

The majority of the lakes investigated in this study showed a good distribution of the dissolved nutrients despite their huge depths, they said, adding that the lakes can be split into two main depth-circulation categories based on their climatic conditions.

As long as the temperature increases aren’t extreme, the deep water temperatures of colder lakes, like Lake Shikotsu, Hokkaido, are likely to remain unchanged in warmer winters. Deep water temperatures in warmer lakes will probably rise, the researchers noted.

The information obtained was confirmed by comparisons with single-point measurements from the 1930s. The data showed that a sharp increase in winter temperatures over the years led to water temperatures that do not fall near as low as the temperatures of the previous years, and depth circulation can stop on the whole. These types of situations can disturb oxygen supplies and nutrient distribution, which affect the organisms found there.

Water quality in lakes plays a key role in both the tourism sector and industry, particularly for water and fishing enterprises. The UFZ scientists, in cooperation with Australian, Canadian and Spanish researchers, are working on numeric lake simulation models that will help offer predictions about water quality under altered conditions, they said.

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