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DOI | 10.1073/pnas.1918412117 |
Algal photophysiology drives darkening and melt of the Greenland Ice Sheet | |
Williamson, Christopher J.1; Cook, Joseph2; Tedstone, Andrew1; Yallop, Marian3; McCutcheon, Jenine4; Poniecka, Ewa5; Campbell, Douglas6; Irvine-Fynn, Tristram2; McQuaid, James4; Tranter, Martyn1; Perkins, Rupert5; Anesio, Alexandre7 | |
2020-03-17 | |
发表期刊 | PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
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ISSN | 0027-8424 |
出版年 | 2020 |
卷号 | 117期号:11页码:5694-5705 |
文章类型 | Article |
语种 | 英语 |
国家 | England; Wales; Canada; Denmark |
英文摘要 | Blooms of Zygnematophycean "glacier algae" lower the bare ice albedo of the Greenland Ice Sheet (GrIS), amplifying summer energy absorption at the ice surface and enhancing meltwater runoff from the largest cryospheric contributor to contemporary sea-level rise. Here, we provide a step change in current understanding of algal-driven ice sheet darkening through quantification of the photophysiological mechanisms that allow glacier algae to thrive on and darken the bare ice surface. Significant secondary phenolic pigmentation (11 times the cellular content of chlorophyll a) enables glacier algae to tolerate extreme irradiance (up to similar to 4,000 mu mol photons center dot m(-2)center dot s(-1)) while simultaneously repurposing captured ultraviolet and short-wave radiation for melt generation. Total cellular energy absorption is increased 50-fold by phenolic pigmentation, while glacier algal chloroplasts positioned beneath shading pigments remain low-light-adapted (E-k similar to 46 mu mol photons center dot m(-2)center dot s(-1)) and dependent upon typical nonphotochemical quenching mechanisms for photoregulation. On the GrIS, glacier algae direct only similar to 1 to 2.4% of incident energy to photochemistry versus 48 to 65% to ice surface melting, contributing an additional similar to 1.86 cm water equivalent surface melt per day in patches of high algal abundance (similar to 10(4) cells center dot mL(-1)). At the regional scale, surface darkening is driven by the direct and indirect impacts of glacier algae on ice albedo, with a significant negative relationship between broadband albedo (Moderate Resolution Imaging Spectroradiometer [MODIS]) and glacier algal biomass (R-2 = 0.75, n = 149), indicating that up to 75% of the variability in albedo across the southwestern GrIS may be attributable to the presence of glacier algae. |
英文关键词 | Greenland Ice Sheet glacier algae photophysiology melt cryosphere |
领域 | 地球科学 ; 气候变化 ; 资源环境 |
收录类别 | SCI-E |
WOS记录号 | WOS:000520011000026 |
WOS关键词 | XANTHOPHYLL CYCLE ; LIGHT ; SURFACE ; MODEL ; ULTRASTRUCTURE ; CHLOROPHYTA ; DYNAMICS ; GLACIERS |
WOS类目 | Multidisciplinary Sciences |
WOS研究方向 | Science & Technology - Other Topics |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/249647 |
专题 | 资源环境科学 |
作者单位 | 1.Univ Bristol, Bristol Glaciol Ctr, Bristol BS8 1HH, Avon, England; 2.Aberystwyth Univ, Dept Geog & Earth Sci, Aberystwyth SY23 3FL, Ceredigion, Wales; 3.Univ Bristol, Sch Biol Sci, Bristol BS8 1TQ, Avon, England; 4.Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire, England; 5.Cardiff Univ, Sch Earth & Ocean Sci, Cardiff CF10 3AT, Wales; 6.Mt Allison Univ, Dept Biol, Sackville, NB E4L 3M7, Canada; 7.Aarhus Univ, Dept Environm Sci, DK-4000 Roskilde, Denmark |
推荐引用方式 GB/T 7714 | Williamson, Christopher J.,Cook, Joseph,Tedstone, Andrew,et al. Algal photophysiology drives darkening and melt of the Greenland Ice Sheet[J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,2020,117(11):5694-5705. |
APA | Williamson, Christopher J..,Cook, Joseph.,Tedstone, Andrew.,Yallop, Marian.,McCutcheon, Jenine.,...&Anesio, Alexandre.(2020).Algal photophysiology drives darkening and melt of the Greenland Ice Sheet.PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,117(11),5694-5705. |
MLA | Williamson, Christopher J.,et al."Algal photophysiology drives darkening and melt of the Greenland Ice Sheet".PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 117.11(2020):5694-5705. |
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