气候变化领域集成服务门户(CCPortal): Impact of permafrost degradation on the extreme increase of dissolved iron concentration in the Amur river during 1995-1997

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DOI	10.1186/s40645-024-00619-w
	Impact of permafrost degradation on the extreme increase of dissolved iron concentration in the Amur river during 1995-1997
	Tashiro, Yuto; Hiyama, Tetsuya; Kanamori, Hironari; Kondo, Masayuki
发表日期	2024
ISSN	2197-4284
起始页码	11
结束页码	1
卷号	11 期号:1
英文摘要	Primary production in the Sea of Okhotsk is largely supported by dissolved iron (dFe) transported by the Amur river, indicating the importance of dFe discharge from terrestrial environments. However, little is known about the mechanisms of dFe discharge into the Amur river, especially in terms of long-term change in dFe concentration. In the Amur river, extreme increase in dFe concentration was observed between 1995 and 1997, the cause of which remains unclear. As a cause of this iron anomaly, we considered the impact of permafrost degradation. To link the permafrost degradation to long-term variation in dFe concentration, we examined the changes in annual air temperature (Ta), accumulated temperature (AT), and net precipitation for three regions (northeast, south, and northwest) of the basin between 1960 and 2006. Ta and AT were relatively high in one out of every few years, and were especially high during 1988-1990 continuously. Net precipitation in late summer (July to September) has increased since 1977 and has stayed positive until 2006 throughout the basin. Most importantly, we found significant correlations between Ta and late summer dFe concentration with a 7-year lag (r = 0.54-0.69, p < 0.01), which indicate a close relationship between high Ta in year Y and increased late summer dFe concentration in year Y + 7. This correlation was the strongest in northeastern Amur basin where permafrost coverage is the highest. Similar 7-year lag correlation was also found between AT in the northeastern basin and late summer dFe concentration (r = 0.51, p < 0.01). Based on our findings, we propose the following hypothesis as a cause of iron anomaly. (1) Increased net precipitation since 1977 has increased soil moisture, which created suitable conditions for microbial dFe generation; (2) permafrost degradation during the warm years of 1988-1990 promoted iron bioavailability and led to the intensive dFe generation in the deeper part of the active layer; and (3) dFe took approximately 7 years to reach the rivers and extremely increased dFe concentration during 1995-1997. This is the first study to suggest the time-lagged impact of permafrost degradation on iron biogeochemistry in the Amur river basin.
英文关键词	Amur river; Dissolved iron; Permafrost; Climate change; Pacific decadal oscillation
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:001190982600001
来源期刊	PROGRESS IN EARTH AND PLANETARY SCIENCE
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/305290
作者单位	Nagoya University; Hiroshima University
推荐引用方式 GB/T 7714	Tashiro, Yuto,Hiyama, Tetsuya,Kanamori, Hironari,et al. Impact of permafrost degradation on the extreme increase of dissolved iron concentration in the Amur river during 1995-1997[J],2024,11(1).
APA	Tashiro, Yuto,Hiyama, Tetsuya,Kanamori, Hironari,&Kondo, Masayuki.(2024).Impact of permafrost degradation on the extreme increase of dissolved iron concentration in the Amur river during 1995-1997.PROGRESS IN EARTH AND PLANETARY SCIENCE,11(1).
MLA	Tashiro, Yuto,et al."Impact of permafrost degradation on the extreme increase of dissolved iron concentration in the Amur river during 1995-1997".PROGRESS IN EARTH AND PLANETARY SCIENCE 11.1(2024).