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John Mickett

Senior Oceanographer

Email

jmickett@apl.washington.edu

Phone

206-897-1795

Department Affiliation

Ocean Physics

Education

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

Projects

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

SMILE: the Submesoscale MIxed-Layer Eddies experiment

More Info

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

More Projects

Videos

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

More Videos

Publications

2000-present and while at APL-UW

Observations of double diffusive staircase edges in the Arctic Ocean

Boury, S., and 9 others including J.B. Mickett, "Observations of double diffusive staircase edges in the Arctic Ocean," J. Geophys. Res., 127, doi:10.1029/2022JC018906, 2022.

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1 Nov 2022

Recent observational studies have provided detailed descriptions of double-diffusive staircases in the Beaufort Sea, characterized by well-mixed intrusions between high-gradient interfaces. These structures result from double-diffusive convection, occurring when cooler fresh water lies atop the warmer saltier Atlantic water layer. In the present study, we investigate the spatial structure of such layers, by analyzing combined high resolution data from a subsurface mooring, a ship-towed profiling conductivity-temperature-depth/ADCP package, and a free-falling microstructure profiler. At large scale, the modular microstructure profiler data suggest a horizontal "ragged edge" of the layered water masses near the basin boundary. At smaller scales, the mooring data indicate that, in the 300–400 m depth interval, regions of layers abruptly appear. This laterally sharp (of the order of 100 m) interface is advected southwards, as shown by the shallow water integrated mapping system survey conducted nearby. Neither disruption nor formation of layers is directly observed in our data, and we thus interpret our observations as the stable and possibly recent abutment of a layered and an unlayered water masses, now globally advected southwards by a large scale flow.

Double diffusion, shear instabilities, and heat impacts of a Pacific Summer Water intrusion in the Beaufort Sea

Fine, E.C., and nine others including J.B. Mickett, "Double diffusion, shear instabilities, and heat impacts of a Pacific Summer Water intrusion in the Beaufort Sea," J. Phys. Oceanogr., 52, 189-203, doi:10.1175/JPO-D-21-0074.1, 2022.

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1 Feb 2022

Pacific Summer Water eddies and intrusions transport heat and salt from boundary regions into the western Arctic basin. Here we examine concurrent effects of lateral stirring and vertical mixing using microstructure data collected within a Pacific Summer Water intrusion with a length scale of ~20 km. This intrusion was characterized by complex thermohaline structure in which warm Pacific Summer Water interleaved in alternating layers of O(1) m thickness with cooler water, due to lateral stirring and intrusive processes. Along interfaces between warm/salty and cold/freshwater masses, the density ratio was favorable to double-diffusive processes. The rate of dissipation of turbulent kinetic energy (ε) was elevated along the interleaving surfaces, with values up to 3 x 10-8 W kg-1 compared to background ε of less than 10-9 W kg-1. Based on the distribution of ε as a function of density ratio Rρ, we conclude that double-diffusive convection is largely responsible for the elevated ε observed over the survey. The lateral processes that created the layered thermohaline structure resulted in vertical thermohaline gradients susceptible to double-diffusive convection, resulting in upward vertical heat fluxes. Bulk vertical heat fluxes above the intrusion are estimated in the range of 0.2–1 W m-2, with the localized flux above the uppermost warm layer elevated to 2–10 W m-2. Lateral fluxes are much larger, estimated between 1000 and 5000 W m-2, and set an overall decay rate for the intrusion of 1–5 years.

Double diffusion, shear instabilities, and heat impacts of a Pacific Summer Water intrusion in the Beaufort Sea

Fine, E.C., J.A. MacKinnon, M.H. Alford, L. Middleton, J. Taylor, J.B. Mickett, S.T. Cole, N. Couto, A. Le Boyer, and T. Peacock, "Double diffusion, shear instabilities, and heat impacts of a Pacific Summer Water intrusion in the Beaufort Sea," J. Phys. Oceanogr., 52, doi:10.1175/JPO-D-21-0074.1, 2022.

More Info

1 Feb 2022

Pacific Summer Water eddies and intrusions transport heat and salt from boundary regions into the western Arctic basin. Here we examine concurrent effects of lateral stirring and vertical mixing using microstructure data collected within a Pacific Summer Water intrusion with a length scale of ~20 km. This intrusion was characterized by complex thermohaline structure in which warm Pacific Summer Water interleaved in alternating layers of O(1) m thickness with cooler water, due to lateral stirring and intrusive processes. Along interfaces between warm/salty and cold/freshwater masses, the density ratio was favorable to double-diffusive processes. The rate of dissipation of turbulent kinetic energy (ε) was elevated along the interleaving surfaces, with values up to 3 x 10-8 W kg-1 compared to background ε of less than 10-9 W kg-1. Based on the distribution of ε as a function of density ratio Rρ, we conclude that double-diffusive convection is largely responsible for the elevated ε observed over the survey. The lateral processes that created the layered thermohaline structure resulted in vertical thermohaline gradients susceptible to double-diffusive convection, resulting in upward vertical heat fluxes. Bulk vertical heat fluxes above the intrusion are estimated in the range of 0.2-1 W m-2, with the localized flux above the uppermost warm layer elevated to 2–10 W m-2. Lateral fluxes are much larger, estimated between 1000 and 5000 W m-2, and set an overall decay rate for the intrusion of 1–5 years.

More Publications

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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