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John Mickett

Senior Oceanographer





Department Affiliation

Ocean Physics


B.S. Marine Science, U.S. Coast Guard Academy, 1994

M.S. Physical Oceanography, University of Washington - Seattle, 2002

Ph.D. Physical Oceanography, University of Washington - Seattle, 2007


Submesoscale Mixed-Layer Dynamics at a Mid-Latitude Oceanic Front

SMILE: the Submesoscale MIxed-Layer Eddies experiment

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1 Mar 2017

This experiment is aimed at increasing our understanding of the role of lateral processes in mixed-layer dynamics through a series of ship surveys and Lagrangian array deployments. Instrument deployments and surveys target the upper ocean's adjustment to winter atmospheric forcing events in the North Pacific subtropical front, roughly 800 km north of Hawaii.

This study will improve understanding of 1–10-km scale lateral processes in three-dimensional mixed-layer dynamics in a region of above-average atmospheric forcing, typical mid-ocean mesoscale advection and straining, and typical submesoscale activity. The results will improve the physical basis of mixed-layer parameterizations, leading to better model predictions of air-sea fluxes, gas transfer, and biological productivity.

Tasmania Internal Tide Experiment

The Tasmanian continental slope will be instrumented with a range of tools including moored profiler, chi-pods, CTDs, and gliders to understand the process, strength, and distribution of ocean mixing from breaking internal waves.

27 Nov 2011

Samoan Passage Abyssal Mixing

The Samoan Passage, 5500 m beneath the sea surface, is one of the "choke points" in the abyssal circulation. A veritable river of Antarctic Bottom water flows through it on its way into the North Pacific. As it enters the constriction, substantial turbulence, hydraulic processes and internal waves must occur, which modify the water. The overall goal is to understand these deep processes and the way they impact the flow, and to develop a strategy for eventually monitoring the flow through the Passage.

27 Sep 2011

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Environmental Sample Processor: A Sentry for Toxic Algal Blooms off the Washington Coast

An undersea robot that measures harmful algal species has been deployed by APL, UW, and NOAA researchers off the Washington coast near La Push. Algal bloom toxicity data are relayed to shore in near-real time and displayed through the NANOOS visualization system. The Environmental Sample Processor, or ESP, is taking measurements near the Juan de Fuca eddy, which is a known incubation site for toxic blooms that often travel toward coastal beaches, threatening fisheries and human health.

22 Jun 2016

ORCA Tracks the 'Blob'

A 'blob' of very warm surface water developed in the northeastern Pacific Ocean in 2014–2015 and its influence extended to the inland waters of Puget Sound throughout the summer of 2015. The unprecedented conditions were tracked by the ORCA (Oceanic Remote Chemical Analyzer) buoy network — an array of six heavily instrumented moored buoys in the Sound. ORCA data provided constant monitoring of evolving conditions and allowed scientists to warn of possible fish kill events in the oxygen-starved waters of Hood Canal well in advance.

The ORCA network is maintained by a partnership among APL-UW, the UW College of the Environment, and the UW School of Oceanography.

3 Nov 2015

ArcticMix 2015

APL-UW physical oceanographers John Mickett and Mike Gregg joined SIO colleagues during September 2015 in the Beaufort Sea aboard the R/V Sikuliaq to measure upper ocean mixing that billows heat from depth to the surface. These mixing dynamics may be an important factor in hastening sea ice melt during summer and delaying freeze-up in the fall.

14 Oct 2015

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2000-present and while at APL-UW

Phenotypic plasticity and carryover effects in an ecologically important bivalve in response to changing environments

Alma, L., P. McElhany, R.N. Crim, J.A. Newton, M. Maher, J.B. Mickett, and J.L. Padilla-Gamino, "Phenotypic plasticity and carryover effects in an ecologically important bivalve in response to changing environments," Front. Mar. Sci., 11, doi:10.3389/fmars.2024.1178507, 2024.

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13 Mar 2024

Phenotypic plasticity can improve an organism’s fitness when exposed to novel environmental conditions or stress associated with climate change. Our study analyzed spatiotemporal differences in phenotypic plasticity and offspring performance in Olympia oysters Ostrea lurida. This species is an ecosystem engineer and is of great interest for commercial and restoration aquaculture. We used a multidisciplinary approach to examine acute and long-term physiological differences in O. lurida in response to in situ oceanographic conditions in a dynamic inland sea. We outplanted oysters to different areas in Puget Sound, Washington, affixing cages to anchor lines of oceanographic monitoring buoys. This allowed us to couple high-resolution oceanographic data with organism's phenotypic response. To assess spatiotemporal differences in oyster physiological performance, we collected oysters after six-months and one year of acclimatization at four field sites. During each collection period we evaluated changes in shell properties, diet, metabolism, and reproduction. Adult growth, δ13°C and δ15°N isotopic signatures, and gametogenesis were affected by both seasonal and environmental conditions. In the winter, oysters from all sites had higher respiration rates when exposed to acute thermal stress, and lower respiration response to acute pH stress. Lipid content, sex ratio and shell strength were unchanged across locations. Offspring growth rates between sites at experimental temperature 20°C closely reflected parental growth rate patterns. Offspring survival was not correlated with growth rates suggesting different energetic trade-offs in oyster offspring. The metabolic response (respiration) of larvae reached its highest point at 20°C but sharply decreased at 25°C. This indicates that larvae are more sensitive to temperature stress, as adults did not exhibit a reduction in metabolic response at 25°C. By deploying genetically similar oysters into distinct environments and employing a wide range of physiological methodologies to examine performance and fitness, our results indicate that Olympia oysters exhibit a high degree of phenotypic plasticity and show evidence of parental carryover.

Subsurface acoustic ducts in the Northern California current system

Xu, G., R.R. Harcourt, D. Tang, B.T. Hefner, E.I. Thorsos, and J.B. Mickett, "Subsurface acoustic ducts in the Northern California current system," J. Acoust. Soc. Am., 155, 1881-1894, doi:10.1121/10.0024146, 2024.

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7 Mar 2024

This study investigates the subsurface sound channel or acoustic duct that appears seasonally along the U.S. Pacific Northwest coast below the surface mixed layer. The duct has a significant impact on sound propagation at mid-frequencies by trapping sound energy and reducing transmission loss within the channel. A survey of the sound-speed profiles obtained from archived mooring and glider observations reveals that the duct is more prevalent in summer to fall than in winter to spring and offshore of the shelf break than over the shelf. The occurrence of the subsurface duct is typically associated with the presence of a strong halocline and a reduced thermocline or temperature inversion. Furthermore, the duct observed over the shelf slope corresponds to a vertically sheared along-slope velocity profile, characterized by equatorward near-surface flow overlaying poleward subsurface flow. Two potential duct formation mechanisms are examined in this study, which are seasonal surface heat exchange and baroclinic advection of distinct water masses. The former mechanism regulates the formation of a downward-refracting sound-speed gradient that caps the duct near the sea surface, while the latter contributes to the formation of an upward-refracting sound-speed gradient that defines the duct's lower boundary.

Large and transient positive temperature anomalies in Washington's coastal nearshore waters during the 2013–2015 Northeast Pacific marine heatwave

Koehlinger, J.A., J. Newton, J. Mickett, L. Thompson, and T. Klinger, "Large and transient positive temperature anomalies in Washington's coastal nearshore waters during the 2013–2015 Northeast Pacific marine heatwave," Plos One, 18, doi:10.1371/journal.pone.0280646, 2023.

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1 Feb 2023

The northern portion of Washington's outer coast — known locally as the Olympic coast — is a dynamic region characterized by seasonal upwelling that predominates during summer interrupted by occasional periods of downwelling. We examined spring-to-fall water temperature records collected along this coast from 2001–2015 from April to October at four nearshore locations (Cape Elizabeth to Makah Bay) that span one degree of latitude and are located within 15 km of the shore. When compared against a long-term climatology created for 2001–2013, seven-day smoothed temperature anomalies of up to 4.5°C at 40 m depth during 2014 and 2015 show short-term warm events lasting 10–20 days. These periods of warming occurred within the well documented marine heatwave in the Northeast Pacific and were about twice the seasonal temperature range in the climatology at that depth. These warm events were strongly correlated with periods of northward long-shore winds and upper ocean currents, consistent with what is expected for the response to downwelling-favorable winds. While our focus a priori was on 2014 and 2015, we also found large positive temperature events in 2013, which were potentially related to the early stage of the marine heatwave, and in 2011, which did not have a documented marine heatwave. This indicates that near-shore short-term warm events occur during periods of large-scale offshore marine heatwave events, but also can occur in the absence of a large-scale marine heatwave event when downwelling-favorable winds occur during the summer/early fall.

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In The News

Ocean trash: What you need to know

KCTS9/EarthFix , Ken Christensen

Ocean currents carry man-made debris to remote corners of the planet—even to places mostly untouched by people. And that makes it difficult to clean up, as APL-UW's Senior Oceanographer John Mickett demonstrates during his recent sojourn to Vancouver Island, B.C. to recover a wayward research buoy.

11 Dec 2017

UW, NOAA deploy ocean robot to monitor harmful algal blooms off Washington coast

UW News and Information, Hannah Hickey

John Mickett, an oceanographer at the UW Applied Physics Laboratory, led the deployment of the new instrument with Stephanie Moore, a scientist at NOAA’s Northwest Fisheries Science Center, as part of a larger collaborative project.

25 May 2016

Buoy deployed in Bellingham Bay to chart health of Puget Sound

KING 5 News, Alison Morrow

Oceanographers deployed a buoy in Bellingham Bay on Thursday that will chart the health of Puget Sound. It joins a half-dozen other buoys, but this is the only one in the north Puget Sound. It is equipped with several pieces of advanced technology that will monitor everything from salinity, temperature and weather changes.

11 Feb 2016

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