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Harper Simmons

Research Scientist/Engineer -Sr. Principal



Department Affiliation

Ocean Physics


B.A. Physics, University of Alaska, 1995

M.S. Coastal Hydrology, University of Alaska, 1996

Ph.D. Physical Oceanography, Florida State University, 2000


2000-present and while at APL-UW

Island Arc Turbulent Eddy Regional Exchange (ARCTERX): Science and Experiment Plan

The ARCTERX Team, "Island Arc Turbulent Eddy Regional Exchange (ARCTERX): Science and Experiment Plan," Technical Report, APL-UW TR 2201. Applied Physics Laboratory, University of Washington, July 2022, 49 pp.

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15 Jul 2022

Submesoscale flows such as fronts, eddies, filaments, and instabilities with lateral dimensions between 100 m and 10 km are ubiquitous features of the ocean. They act as an intermediary between the mesoscale and small-scale turbulence and are thought to have a critical role in closing the ocean's kinetic budget by facilitating a forward energy cascade, where energy is transferred to small scales and dissipated.

The initiative uses a suite of measurements from autonomous platforms and ships combined with regional simulations to characterize the submesoscale flows in the western Pacific Ocean between Luzon and Mariana Island arcs &$151; the ARCTERX region.

Program goals are to characterize the strength and spectral properties of the turbulent cascade of kinetic energy on the submesoscales in the ARCTERX study region and understand the processes that control energy transfers across scales and their seasonal variability.

Estimates of near-inertial wind power input using novel in situ wind measurements from Minimet surface drifters in the Iceland Basin

Klenz, T., H.L. Simmons, L. Centurioni, J.M. Lilly, J.J. Early, and V. Hormann, "Estimates of near-inertial wind power input using novel in situ wind measurements from Minimet surface drifters in the Iceland Basin," J. Phys. Oceanogr., EOR, doi:10.1175/JPO-D-21-0283.1, 2022.

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20 Jun 2022

The Minimet is a Lagrangian surface drifter measuring near-surface winds in situ. Ten Minimets were deployed in the Iceland Basin over the course of two field seasons in 2018 and 2019. We compared Minimet wind measurements to coincident ship winds from the R/V Armstrong meteorology package and to hourly ERA5 reanalysis winds, and found that the Minimets accurately captured wind variability across a variety of timescales. Comparisons between the ship, Minimets and ERA5 winds point to significant discrepancies between the in situ wind measurements and ERA5, with the most reasonable explanation being related to spatial offsets of small-scale storm structures in the reanalysis model. After a general assessment of the Minimet performance we compare estimates of wind power input in the near-inertial band using the Minimet winds and their measured drift to that using ERA5 winds and the Minimet drift. Minimet-derived near-inertial wind power estimates exceed those from Minimet drift combined with ERA5 winds by about 42%. The results highlight the importance of accurately capturing small scale, high frequency wind events and suggest that in situ Minimet measurements are beneficial for accurately quantifying near-inertial wind work on the ocean.

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center