Alternate history: A synthetic ensemble of ocean chlorophyll concentrations Journal Article uri icon

Overview

abstract

  • Internal climate variability plays an important role in the abundance; and distribution of phytoplankton in the global ocean. Previous studies; using large ensembles of Earth system models (ESMs) have demonstrated; their utility in the study of marine phytoplankton variability. These; ESM large ensembles simulate the evolution of multiple alternate; realities, each with a different phasing of internal climate; variability. However, ESMs may not accurately represent real world; variability as recorded via satellite and in situ observations of ocean; chlorophyll over the past few decades. Observational records of surface; ocean chlorophyll equate to a single ensemble member in the large; ensemble framework, and this can cloud the interpretation of long-term; trends: are they externally forced, caused by the phasing of internal; variability, or both? Here, we use a novel statistical emulation; technique to place the observational record of surface ocean chlorophyll; into the large ensemble framework. Much like a large initial condition; ensemble generated with an ESM, the resulting synthetic ensemble; represents multiple possible evolutions of ocean chlorophyll; concentration, each with a different phasing of internal climate; variability. We further demonstrate the validity of our statistical; approach by recreating a ESM ensemble of chlorophyll using only a single; ESM ensemble member. We use the synthetic ensemble to explore the; interpretation of long-term trends in the presence of internal; variability. Our results suggest the potential to explore this approach; for other ocean biogeochemical variables.

publication date

  • January 4, 2021

has restriction

  • hybrid

Date in CU Experts

  • January 9, 2021 10:21 AM

Full Author List

  • Elsworth G; Lovenduski N; McKinnon K

author count

  • 3

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