Oregon State University

College of Earth, Ocean, and Atmospheric Sciences

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Johannes Becherer

Johannes Becherer photo
Research Associate (Postdoc)
Discipline: Physics of Oceans and Atmospheres
Office: Burt 432
Email: jbechere@coas.oregonstate.edu

Specialty

  • turbulent mixing
  • non-linear internal waves
  • submesoscale processes
  • baroclinic instabilities
  • tidal channel flows
  • estuarine circulation
  • curved flows
  • buoyancy driven flows
  • boundary mixing
  • mixing asymmetries
  • estuarine sediment dynamics
  • large scale internal waves

Research Interests

Since 2015, I am working as a PostDoc in the Ocean Mixing Group together with Jim Moum. I am mainly working in the Inner Shelf DRI (Office of Naval Research), which is a large project that aims to understand the complex interactions of different physical processes that drive the dynamics on the inner shelf. Such processes include submesoscale eddies, up- and down-welling, internal tides, internal solitary waves, as well assurface and bottom boundary layer dynamics. My personal focus in this project is to study how these different processes interact to facilitate diapycnal mixing and what are the pathways of energy dissipation on the shelf.

In addition, I am investigating turbulent mixing at the Equator, the Bay of Bengal, and several coastal regions. I also developed data reduction strategies to enable long term mixing monitoring based on satellite communication.

During my first PostDoc, I was working on morphologic modelingof the Wadden Sea, developing code and conducting expensive numerical model simulations, using the super computer infrastructure at the HLRN in Germany.

During my PhD, I studied estuarine circulation as a major driver for sediment transportinto the Wadden Sea. Based on observational data, I was able to point out the dynamical importance of lateral circulation. With the help of a newly developed mathematical frame work, I discovered a characteristic dynamical feedback between centrifugal forcing and baroclinic pressure gradient. Furthermore, I was able to show that this feedback is the major control of vertical stratification and along channel exchange flow in the Wadden Sea. In addition, I developed an idealized model, which I used for a parameter study, to point out the global relevance of the newly discovered effect.

During my master thesis I was investigating boundary mixing in lakes, in detail large scale internal waves (seiches), bottom boundary layer stratification, mixing and turbulence. Since my thesis was a process-oriented modeling study based on model data, I learned how to setup and apply 3D-circulation models. Understanding the principles of state of the art turbulence closure models and there application was part of my thesis as well.

Education

11 Jul 2014       PhD in physical oceanography (Dr. rer. nat.), University of Rostock

  • Title: Estuarine Circulation in well-mixed tidal inlets
  • Supervisor: Hans Burchard

Feb-Apr 2013    Visiting Scholar at the University of California Berkeley
Nov 2011           Visiting Scholar at the Woods Hole Oceanographic Institution

2010-2013        PhD-studies, Leibniz Institute for Baltic Sea Research Warnemüde

22 Feb 2010     Master of Science (Dipl. phys.), University of Rostock

  • Title: The Effect of Shear-Induced Bottom Boundary Layer Stratification on Diapycnal Mixing: A Modeling Study
  • Supervisor: Lars Umlauf

2003-2010        Studying physics, University of Rostock

Publications

Becherer, J., and J. N. Moum (2017), An efficient scheme for onboard reduction of moored χpod
data, Journal of Atmospheric and Oceanic Technology.

Hofstede, J., J. Becherer, and H. Burchard (submitted), Morphologische Projektionen für zwei
Tidesysteme im Wattenmeer von Schleswig-Holstein: SH-TREND, Die Küste.

Becherer, J., J. Hofstede, U. Gräwe, K. Purkiani, E. Schulz, and H. Burchard (2017), The Wadden
Sea in transition - consequences of sea level rise, Ocean Dynamics, 1-21.

Hofstede, J.L.A., Becherer, J. and Burchard, H. (2016), Are Wadden Sea tidal systems with a higher
tidal range more resilient against sea level rise? Journal of Coastal Conservation.

Warner, S.J., J. Becherer, K. Pujiana, E.L. Shroyer, M. Ravichandran, V.P. Thangaprakash, and J.N. Moum. (2016). Monsoon mixing cycles in the Bay of Bengal: A year-long subsurface mixing record. Oceanography 29(2), http://dx.doi.org/10.5670/ oceanog.2016.xx.

Becherer,  J., G. Flöser, L. Umlauf, and H. Burchard (2016),   Estuarine Circulation vs Tidal Pumping:
Sediment Transport in a Well-Mixed Tidal Inlet, J. Geophys. Res, 

Purkiani, K., J. Becherer, K. Klingbeil, and H. Burchard (2016),   Wind-induced variability of estuarine circulation in a tidally energetic inlet with curvature, J. Geophys. Res

Becherer, J., M. T. Stacey, L. Umlauf, and H. Burchard (2015), Lateral circulation generates flood tide stratification and estuarine exchange flow in a curved tidal inlet., J. Phys. Oceanogr., 45, 638–656, doi: 10.1175/JPO-D-14-0001.1

Purkiani, K., J. Becherer, G. Flöser, U. Gräwe, V. Mohrholz, H. M. Schuttelaars, and H. Burchard (2015), Numerical analysis of stratification and destratification processes in a tidally energetic inlet with an ebb tidal delta, J. Geophys. Res. Oceans, 120, 225243, doi:10.1002/2014JC010325.

Becherer, J., H. Burchard, G. Flöser, V. Mohrholz, and L. Umlauf (2011), Evidence of tidal straining in well-mixed channel flow from micro-structure observations, Geophys. Res. Lett., 38, L17611, doi:10.1029/2011GL049005.

Becherer, J. K., and L. Umlauf (2011), Boundary mixing in lakes: 1. Modeling the effect of shear-induced convection, J. Geophys. Res., 116, C10017, doi:10.1029/2011JC007119.

Lorrai, C., L. Umlauf, J. K. Becherer, A. Lorke, and A. Wüest (2011), Boundary mixing in lakes: 2. Combined effects of shear- and convectively induced turbulence on basin-scale mixing, J. Geophys. Res., 116, C10018, doi:10.1029/2011JC007121.

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