Tokyo, October 12 (IANS). Climate change has also affected the weather in Japan. This claim is reported by a university research group. It shows that summer in Japan has become approximately three weeks longer in the 42 years from 1982 to 2023.
Kyodo news agency quoted the ‘Mi University’ group as saying that due to climate change, the number of days classified as summer has increased each year, while winter has remained unchanged, and the average length of spring and autumn has shortened.
The group cited “increased sea surface temperatures due to global warming” as the main factor and warned that “these trends will accelerate if this continues.”
The Japan Meteorological Agency defines summer as the period from June to August, but does not specify a temperature range.
The researchers included second-year postgraduate student Mao Takikawa and Professor Yoshihiro Tachibana of the university’s Department of Environmental Science and Technology.
In their research, the group divided the region from Japan’s main northern island, Hokkaido, to its southernmost island, Kyushu, including surrounding marine areas, into about 200 regions and calculated 42 years of average annual maximum temperatures using the agency’s observational data.
They set a “summer standard” for each region based on its temperature range, and used the agency’s annual high and low temperature data to determine which days would be considered summer days.
They analyzed 42 years of temperature data on an annual basis.
Looking at the average of about 200 zones over a period of 42 years, the start date of summer was moved forward by about 12.6 days, while the end date was delayed by about 8.8 days.
The group reported that the duration of the summer season increased by about 21.4 days.
In 1982, the summer season lasted 92 days, from June 29 to September 28. However, by 2023, it has increased to 121 days and runs from June 11 to October 9.
According to Tachibana, warm winds from the Asian continent once cooled over the oceans surrounding the Japanese archipelago, causing temperatures to gradually rise from spring to summer. However, in recent years, rising sea surface temperatures have halted this cooling, resulting in earlier summers.
Tachibana said the ocean surface is staying warm, making it difficult for temperatures to drop and delaying the end of summer.
Meanwhile, no significant changes have been observed during the winter period. It is believed that this is due to the continuous impact of strong cold waves coming from the continent.
–IANS
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