About

Mathis P Hain is a researcher involved in the field of Earth System Biogeochemistry at the University of California, Santa Cruz. His work explores how the major element cycles of life have changed throughout Earth's history, with a focus on understanding the natural processes that have shaped global nutrient and carbon cycling. He employs computational methods to simulate carbon and nutrient cycling, matching these simulations to available reconstructions to better understand the role of the global carbon cycle in past climate change. His research also investigates the processes that sustain the ocean’s biological productivity by supplying essential nutrients. By studying these natural processes, Hain aims to inform predictions about how the environment may change in the future. His contributions include addressing questions related to environmental change, ice ages, and the carbon cycle, and he actively engages with the scientific community through publications, podcasts, and other outreach activities.

Research topics

• Oceanography
• Geology
• Climatology
• Environmental science
• Biology
• Chemistry
• Materials science
• Earth science
• Environmental chemistry
• Paleontology
• Ecology

Selected publications

• Global reorganization of deep-sea circulation and carbon storage after the last ice age

  Science Advances · 2022 · 74 citations

  • Oceanography
  • Geology
  • Climatology

  .

  DOI

• A 35-million-year record of seawater stable Sr isotopes reveals a fluctuating global carbon cycle

  Science · 2021 · 70 citations

  • Oceanography
  • Environmental science
  • Environmental chemistry

  Sr data as reflecting changes in the mineralogy and burial location of biogenic carbonates.

  DOI

• The Southern Ocean during the ice ages: A review of the Antarctic surface isolation hypothesis, with comparison to the North Pacific

  Quaternary Science Reviews · 2020 · 139 citations

  • Oceanography
  • Geology
  • Climatology

  The Southern Ocean is widely recognized as a potential cause of the lower atmospheric concentration of CO2 during ice ages, but the mechanism is debated. Focusing on the Southern Ocean surface, we review biogeochemical paleoproxy data and carbon cycle concepts that together favor the view that both the Antarctic and Subantarctic Zones (AZ and SAZ) of the Southern Ocean played roles in lowering ice age CO2 levels. In the SAZ, the data indicate dust-driven iron fertilization of phytoplankton growth during peak ice age conditions. In the ice age AZ, the area-normalized exchange of water between the surface and subsurface appears to have been reduced, a state that we summarize as “isolation” of the AZ surface. Under most scenarios, this change would have stemmed the leak of biologically stored CO2 that occurs in the AZ today. SAZ iron fertilization during the last ice age fits with our understanding of ocean processes as gleaned from modern field studies and experiments; indeed, this hypothesis was proposed prior to evidentiary support. In contrast, AZ surface isolation is neither intuitive nor spontaneously generated in climate model simulations of the last ice age. In a more prospective component of this review, the suggested causes for AZ surface isolation are considered in light of the subarctic North Pacific (SNP), where the paleoproxies of productivity and nutrient consumption indicate similar upper ocean biogeochemical changes over glacial cycles, although with different timings at deglaciation. Among the proposed initiators of glacial AZ surface isolation, a single mechanism is sought that can explain the changes in both the AZ and the SNP. The analysis favors a weakening and/or equatorward shift in the upwelling associated with the westerly winds, occurring in both hemispheres. This view is controversial, especially for the SNP, where there is evidence of enhanced upper water column ventilation during the last ice age. We offer an interpretation that may explain key aspects of the AZ and SNP observations. In both regions, with a weakening in westerly wind-driven upwelling, nutrients may have been “mined out” of the upper water column, possibly accompanied by a poleward “slumping” of isopycnals. In the AZ, this would have encouraged declines in both the nutrient content and the formation rate of new deep water, each of which would have contributed to the lowering of atmospheric CO2. Through several effects, the reduction in AZ upwelling may have invigorated the upwelling of deep water into the low latitude pycnocline, roughly maintaining the pycnocline’s supply of water and nutrients so as to (1) support the high productivity of the glacial SAZ and (2) balance the removal of water from the pycnocline by the formation of Glacial North Atlantic Intermediate Water. The proposed return route from the deep ocean to the surface resembles that of Broecker’s (1991) “global ocean conveyor,” but applying to the ice age as opposed to the modern ocean.

  DOI

Frequent coauthors

• Gavin L. Foster

  University of Southampton

  47 shared

• Gerald H. Haug

  34 shared

• Thomas B. Chalk

  Aix-Marseille Université

  34 shared

• Daniel M. Sigman

  Princeton University

  27 shared

• Rosanna Greenop

  University of St Andrews

  27 shared

• Luke C Skinner

  25 shared

• James Rae

  24 shared

• Thomas M. Marchitto

  22 shared

Education

• PhD, Geosciences

  Princeton University

  2013

• Dipl. geol. (MSc-level) , Geoscience

  Universitat Potsdam

  2008

Similar researchers at University of California, Santa Cruz

• Jonathan J Fortneyh-125
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• Piero Madauh-108
• Jin Zhong Zhangh-106
• Carol Greiderh-100