Drought recorded by Ba∕Ca in coastal benthic foraminifera

• Published in: Biogeosciences
• Main Authors: Brinkmann, Inda, Barras, Christine, Jilbert, Tom, Næraa, Tomas, Paul, K. Mareike, Schweizer, Magali, Filipsson, Helena L.
• Format: Text
• Language: English
• Published: 2022
• Subjects: Planktonic foraminifera
• Online Access: https://doi.org/10.5194/bg-19-2523-2022; https://bg.copernicus.org/articles/19/2523/2022/

Increasing occurrences of extreme weather events, such as the 2018 drought over northern Europe, are a concerning issue under global climate change. High-resolution archives of natural hydroclimate proxies, such as rapidly accumulating sediments containing biogenic carbonates, offer the potential to investigate the frequency and mechanisms of such events in the past. Droughts alter the barium (Ba) concentration of near-continent seawater through the reduction in Ba input from terrestrial runoff, which in turn may be recorded as changes in the chemical composition ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">Ba</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="36pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="6ce6b2dd58dbf3d0c1decb3ec17e2c09"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-2523-2022-ie00004.svg" width="36pt" height="14pt" src="bg-19-2523-2022-ie00004.png"/></svg:svg> ) of foraminiferal calcium carbonates accumulating in sediments. However, so far the use of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">Ba</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="36pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="037b0ce808850503cd416a493f08c518"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-2523-2022-ie00005.svg" width="36pt" height="14pt" src="bg-19-2523-2022-ie00005.png"/></svg:svg> as a discharge indicator has been restricted to planktonic foraminifera, despite the high relative abundance of benthic species in coastal, ...