Climatic Controls on the Spring Phytoplankton Growing Season in a Temperate Shelf Sea



Jardine, JE, Palmer, M, Mahaffey, C ORCID: 0000-0002-4215-7271, Holt, J, Wakelin, S and Artioli, Y
(2022) Climatic Controls on the Spring Phytoplankton Growing Season in a Temperate Shelf Sea. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 127 (5).

Access the full-text of this item by clicking on the Open Access link.

Abstract

<jats:title>Abstract</jats:title><jats:p>The Northwest European Shelf is positioned directly beneath the North Atlantic Storm Track, within which the frequency and intensity of transient storms are modulated by large‐scale climatic oscillations. In temperate shelf seas, the impact of storms on the physical environment has received considerable attention, but the effect on biogeochemistry is less studied. Here, we use output from a multidecadal (1982–2015) coupled physical‐biogeochemical model supported by observations from ocean gliders to investigate phytoplankton growth throughout the winter‐spring transition. We define two separate phytoplankton growth events: the spring bloom, defined as the exponential growth following seasonal stratification, and the prebloom, occurring before stratification, and accounting for up to 22% of the total spring growth. Our results support the paradigm that light is a first‐order control, with the spring bloom initiating up to 22 days after stratification onset should light levels be too low to trigger the bloom. The prebloom is heavily influenced by the phase of the Atlantic Multidecadal Oscillation (AMO), demonstrated by an acceleration in the rate of increase of total chlorophyll concentrations (±90% confidence limit) from 7.6 ± 2.8 mg m<jats:sup>−2</jats:sup> d<jats:sup>−1</jats:sup> (during a positive AMO) to 13.1 ± 4.3 mg m<jats:sup>−2</jats:sup> d<jats:sup>−1</jats:sup> (negative AMO), due to modulation of periods of ephemeral stratification that occur between successive storms. We propose that phytoplankton growth in prebloom events might help buffer the lag between phytoplankton supply and larval recruitment, particularly during years when the spring bloom is delayed.</jats:p>

Item Type: Article
Uncontrolled Keywords: AMO, Northwest European Shelf, phytoplankton, spring bloom, storms, stratification
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 07 Jul 2022 09:30
Last Modified: 05 Sep 2023 09:29
DOI: 10.1029/2021JC017209
Open Access URL: https://doi.org/10.1029/2021JC017209
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3157927