Light Availability and Phytoplankton Growth Beneath Arctic Sea Ice: Integrating Observations and Modeling
Journal of Geophysical Research: Oceans
Observations of the seasonal light field in the upper Arctic Ocean are critical to understanding the impacts of changing Arctic ice conditions on phytoplankton growth in the water column. Here we discuss data from a new sensor system, deployed in seasonal ice cover north‐east of Utqiaġvik, Alaska in March 2014. The system was designed to provide observations of light and phytoplankton biomass in the water column during the formation of surface melt ponds and the transition from ice to open water. Hourly observations of downwelling irradiance beneath the ice (at 2.9, 6.9, and 17.9 m depths) and phytoplankton biomass (at 2.9 m depth) were transmitted via Iridium satellite from 9 March to 10 November 2014. Evidence of an under‐ice phytoplankton bloom (Chl a ∼8 mg m−3) was seen in June and July. Increases in light intensity observed by the buoy likely resulted from the loss of snow cover and development of surface melt ponds. A bio‐optical model of phytoplankton production supported this probable trigger for the rapid onset of under‐ice phytoplankton growth. Once under‐ice light was no longer a limiting factor for photosynthesis, open water exposure almost marginally increased daily phytoplankton production compared to populations that remained under the adjacent ice. As strong effects of climate change continue to be documented in the Arctic, the insight derived from autonomous buoys will play an increasing role in understanding the dynamics of primary productivity where ice and cloud cover limit the utility of ocean color satellite observations.
© 2018. American Geophysical Union. All Rights Reserved.
AGU allows authors to deposit their journal articles if the version is the final published citable version of record, the AGU copyright statement is clearly visible on the posting, and the posting is made 6 months after official publication by the AGU.
Article states: "All data from the buoy are publicly available at the NSF Arctic Data Center (https://arcticdata.io/catalog/#view/doi:10.18739/A2J954)."
Original Publication Citation
Hill, V. J., Light, B., Steele, M., & Zimmerman, R. C. (2018). Light availability and phytoplankton growth beneath Arctic sea ice: Integrating observations and modeling. Journal of Geophysical Research: Oceans, 123(5), 3651-3667. doi:http://dx.doi.org/10.1029/2017JC013617
Hill, Victoria J.; Light, Bonnie; Steele, Michael; and Zimmerman, Richard C., "Light Availability and Phytoplankton Growth Beneath Arctic Sea Ice: Integrating Observations and Modeling" (2018). OES Faculty Publications. 292.
Climate Commons, Marine Biology Commons, Oceanography Commons