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Martha's Vineyard Coastal Observatory (MVCO) is a leading research and engineering facility operated by Woods Hole Oceanographic Institution. MVCO has been collecting ocean and atmospheric data at 3 sites on and near Martha's Vineyard since 2001. A meteorological mast (met mast) on South Beach in Edgartown, MA has collected atmospheric data since May 31 2001. An Air Sea Interaction Tower (ASIT) has been collecting atmospheric and subsurface oceanic data since August 5, 2004. A seafloor node (12m node) has been collecting oceanic data from the seafloor since June 14, 2001. This dataset encompasses the core data (wind speed and direction, air pressure, temperature and relative humidity, water temperature and salinity, and wave data) that has been collected during this period. To learn more about the facility and see additional data collected during short term deployments, visit the MVCO Website (https://mvco.whoi.edu/).

Martha's Vineyard Coastal Observatory (MVCO) is a leading research and engineering facility operated by Woods Hole Oceanographic Institution. MVCO has been collecting ocean and atmospheric data at 3 sites on and near Martha's Vineyard since 2001. A meteorological mast (met mast) on South Beach in Edgartown, MA has collected atmospheric data since May 31 2001. An Air Sea Interaction Tower (ASIT) has been collecting atmospheric and subsurface oceanic data since August 5, 2004. A seafloor node (12m node) has been collecting oceanic data from the seafloor since June 14, 2001. This dataset encompasses the core data (wind speed and direction, air pressure, temperature and relative humidity, water temperature and salinity, and wave data) that has been collected during this period. To learn more about the facility and see additional data collected during short term deployments, visit the MVCO Website (https://mvco.whoi.edu/).

Martha's Vineyard Coastal Observatory (MVCO) is a leading research and engineering facility operated by Woods Hole Oceanographic Institution. MVCO has been collecting ocean and atmospheric data at 3 sites on and near Martha's Vineyard since 2001. A meteorological mast (met mast) on South Beach in Edgartown, MA has collected atmospheric data since May 31 2001. An Air Sea Interaction Tower (ASIT) has been collecting atmospheric and subsurface oceanic data since August 5, 2004. A seafloor node (12m node) has been collecting oceanic data from the seafloor since June 14, 2001. This dataset encompasses the core data (wind speed and direction, air pressure, temperature and relative humidity, water temperature and salinity, and wave data) that has been collected during this period. To learn more about the facility and see additional data collected during short term deployments, visit the MVCO Website (https://mvco.whoi.edu/).

Martha's Vineyard Coastal Observatory (MVCO) is a leading research and engineering facility operated by Woods Hole Oceanographic Institution. MVCO has been collecting ocean and atmospheric data at 3 sites on and near Martha's Vineyard since 2001. A meteorological mast (met mast) on South Beach in Edgartown, MA has collected atmospheric data since May 31 2001. An Air Sea Interaction Tower (ASIT) has been collecting atmospheric and subsurface oceanic data since August 5, 2004. A seafloor node (12m node) has been collecting oceanic data from the seafloor since June 14, 2001. This dataset encompasses the core data (wind speed and direction, air pressure, temperature and relative humidity, water temperature and salinity, and wave data) that has been collected during this period. To learn more about the facility and see additional data collected during short term deployments, visit the MVCO Website (https://mvco.whoi.edu/).

Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 126(2), (2021): e2020JC016856, https://doi.org/10.1029/2020JC016856., The genus Phaeocystis is distributed globally and has considerable ecological, biogeochemical, and societal impacts. Understanding its distribution, growth and ecological impacts has been limited by lack of extensive observations on appropriate scales. In 2018, we investigated the biological dynamics of the New England continental shelf and encountered a substantial bloom of Phaeocystis pouchetii. Based on satellite imagery during January through April, the bloom extended over broad expanses of the shelf; furthermore, our observations demonstrated that it reached high biomass levels, with maximum chlorophyll concentrations exceeding 16 µg L−1 and particulate organic carbon levels > 95 µmol L−1. Initially, the bloom was largely confined to waters with temperatures <6°C, which in turn were mostly restricted to shallow areas near the coast. As the bloom progressed, it appeared to sink into the bottom boundary layer; however, enough light and nutrients were available for growth. The bloom was highly productive (net community production integrated through the mixed layer from stations within the bloom averaged 1.16 g C m−2 d−1) and reduced nutrient concentrations considerably. Long‐term coastal observations suggest that Phaeocystis blooms occur sporadically in spring on Nantucket Shoals and presumably expand onto the continental shelf. Based on the distribution of Phaeocystis during our study, we suggest that it can have a significant impact on the overall productivity and ecology of the New England shelf during the winter/spring transition., This project was supported by the US National Science Foundation (Grants 1657855, 1657803, and 1657489). NES‐LTER contributions were supported by grants to HMS from NSF (Grant 1655686) and the Simons Foundation (Grant 561126). VPR operations were supported by the Dalio Explore Fund., 2021-07-15

The metabolism of estuarine environments is often estimated by measuring changes in dissolved oxygen concentrations. A central assumption of common oxygen-based approaches is that oxygen consumption rates (primarily respiration) are similar under light and dark conditions. Evaluating this assumption is critical, especially in benthic-dominated systems, because differences between daytime and nighttime respiration could result in underestimation or overestimation of ecosystem productivity. We evaluated rates of gross oxygen production over hourly to seasonal time scales in a shallow, temperate salt marsh pond. To assess whether a dissolved oxygen diel mass balance underestimated gross oxygen productivity, we compared rates using this traditional approach and using the triple oxygen isotope tracer of photosynthesis. This is a powerful combination because the triple oxygen isotope approach is theoretically insensitive to respiration. The methods agreed well over daily to seasonal time scales. However, during midday periods of peak light and productivity, the triple oxygen isotope approach resulted in higher hourly scale gross oxygen production rates. The timing and magnitude of this short-term difference is consistent with light-dependent oxygen uptake fluxes including photoreduction and/or light-stimulated community respiration. Finally, aquatic vegetation was associated with variability in productivity across the pond. Such small-scale environmental heterogeneity is evidence that this shallow pond was not laterally well mixed, and likely contributes to the dynamism of these common estuarine environments.

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research-Oceans 124(6), (2019): 3628-3644, doi:10.1029/2018JC014805., The Arctic Ocean is experiencing profound environmental changes as the climate warms. Understanding how these changes will affect Arctic biological productivity is key for predicting future Arctic ecosystems and the global CO2 balance. Here we use in situ gas measurements to quantify rates of gross oxygen production (GOP, total photosynthesis) and net community production (NCP, net CO2 drawdown by the biological pump) in the mixed layer in summer or fall from 2011 to 2016 in the Beaufort Gyre. NCP and GOP show spatial and temporal variations with higher values linked with lower concentrations of sea ice and increased upper ocean stratification. Mean rates of GOP range from 8 ± 1 to 54 ± 9 mmol O2·m−2·d−1 with the highest mean rates occurring in summer of 2012. Mean rates of NCP ranged from 1.3 ± 0.2 to 2.9 ± 0.5 mmol O2·m−2·d−1. The mean ratio of NCP/GOP, a measure of how efficiently the ecosystem is recycling its nutrients, ranged from 0.04 to 0.17, similar to ratios observed at lower latitudes. Additionally, a large increase in total photosynthesis that occurred in 2012, a year of historically low sea ice coverage, persisted for many years. Taken together, these data provide one of the most complete characterizations of interannual variations of biological productivity in this climatically important region, can serve as a baseline for future changes in rates of production, and give an intriguing glimpse of how this region of the Arctic may respond to future lack of sea ice., We sincerely thank the scientific teams of Fisheries and Oceans Canada's Joint Ocean Ice Studies expedition and Woods Hole Oceanographic Institution's Beaufort Gyre Observing System. The hydrographic, nutrient, and chlorophyll data were collected and made available by the Beaufort Gyre Exploration Program based at the Woods Hole Oceanographic Institution (http://www.whoi.edu/beaufortgyre) in collaboration with researchers from Fisheries and Oceans Canada at the Institute of Ocean Sciences. We thank the captains and crews of the Canadian icebreaker CCGS Louis S. St‐Laurent and Mike Dempsey for sample collection. This paper was improved by the suggestions of Michael DeGrandpre and one anonymous reviewer. We are grateful to Qing Wang at Wellesley College for her assistance with statistics. We thank our funding sources: the National Science Foundation (NSF 1547011, NSF 1302884, NSF 1719280, NSF 1643735) and the support of Fisheries and Oceans Canada. Data presented and discussed in this paper can be found in the Arctic Data Center (http://10.18739/A2W389)., 2019-10-30

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 130 (2017): 1-11, doi:10.1016/j.dsr.2017.10.005., Modeling studies have shown that mesoscale and submesoscale processes can stimulate phytoplankton productivity and export production. Here, we present observations from an undulating, towed Video Plankton Recorder (VPR-II) in the tropical Atlantic. The VPR-II collected profiles of oxygen, fluorescence, temperature and salinity in the upper 140 m of the water column at a spatial resolution of 1 m in the vertical and <2 km in the horizontal. The data reveal remarkable "hotspots", i.e. locations 5 to 10 km wide which have elevated fluorescence and decreased oxygen, both of which are likely the result of intense submesoscale upwelling. Based on estimates of source water, estimated from identical temperature and salinity surfaces, hotspots are more often areas of net respiration than areas of net production — although the inferred changes in oxygen are subject to uncertainty in the determination of the source of the upwelled waters since the true source water may not have been sampled. We discuss the spatial distribution of these hotspots and present a conceptual model outlining their possible generation and decline. Simultaneous measurements of O2/Ar in the mixed layer from a shipboard mass spectrometer provide estimates of rates of surface net community production. We find that the subsurface biological hotspots are often expressed as an increase in mixed layer rates of net community production. Overall, the large number of these hotspots support the growing evidence that submesoscale processes are important drivers in upper ocean biological production., Funding for this work came from the National Science Foundation (R.H.R.S. and D.J.M) (OCE-0925284, OCE-1048897, and OCE- 1029676) and the National Aeronautics and Space Administration (D.J.M.) (NNX08AL71G and NNX13AE47G).

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 44 (2017): 10511-10519, doi:10.1002/2017GL074375., Measurement of the triple oxygen isotope (TOI) composition of O2 is an established method for quantifying gross oxygen production (GOP) in natural waters. A standard assumption to this method is that the isotopic composition of H2O, the substrate for photosynthetic O2, is equivalent to Vienna standard mean ocean water (VSMOW). We present and validate a method for estimating the TOI composition of H2O based on mixing of local meteoric water and seawater H2O end-members, and incorporating the TOI composition of H2O into GOP estimates. In the ocean, GOP estimates based on assuming the H2O is equivalent to VSMOW can have systematic errors of up to 48% and in low-salinity systems, errors can be a factor of 2 or greater. In future TOI-based GOP studies, TOI measurements of O2 and H2O should be paired when the H2O isotopic composition is expected to differ from VSMOW., NSF Grant Numbers: OCE-1029676, OCE-1233678, PLR-1304406, PLR-1547011; NSERC and CMOS; NDSEG fellowship, 2018-04-25

© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Marine Systems 147 (2015): 29-44, doi:10.1016/j.jmarsys.2014.04.006., The Arctic Ocean is changing rapidly as the global climate warms but it is not well known how these changes are affecting biological productivity and the carbon cycle. Here we study the Beaufort Gyre region of the Canada Basin in August and use the large reduction in summertime sea ice extent from 2011 to 2012 to investigate potential impacts of climate warming on biological productivity. We use the gas tracers O2/Ar and triple oxygen isotopes to quantify rates of net community production (NCP) and gross oxygen production (GOP) in the gyre. Comparison of the summer of 2011 with the summer of 2012, the latter of which had record low sea ice coverage, is relevant to how biological productivity might change in a seasonally ice-free Arctic Ocean. We find that, in the surface waters measured here, GOP in 2012 is significantly greater than in 2011, with the mean basin-wide 2012 GOP = 38 ± 3 mmol O2 m− 2 d− 1 whereas in 2011, mean basin GOP = 16 ± 5 mmol O2 m− 2 d− 1. We hypothesize that this is because the lack of sea ice and consequent increase in light penetration allows photosynthesis to increase in 2012. However, despite the increase in GOP, NCP is the same in the two years; mean NCP in 2012 is 3.0 ± 0.2 mmol O2 m− 2 y− 1 and in 2011 is 3.1 ± 0.2 mmol O2 m− 2 y− 1. This suggests that the heterotrophic community (zooplankton and/or bacteria) increased its activity as well and thus respired the additional carbon produced by the increased photosynthetic production. In both years, stations on the shelf had GOP 3 to 5 times and NCP 2 to 10 times larger than the basin stations. Additionally, we show that in 2011, the NCP/GOP ratio is smallest in regions with highest ice cover, suggesting that the microbial loop was more efficient at recycling carbon in regions where the ice was just starting to melt. These results highlight that although satellite chlorophyll records show, and many models predict, an increase in summertime primary production in the Arctic Basin as it warms, We thank our funding sources: the National Science Foundation (PLR 1304406, PLR-0856531) and the support of Fisheries and Oceans Canada.