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<b><i>"Spurious internal waves generated during Data Assimilation in ocean model simulations"</i></b>
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<div><span style="font-size: 20pt;"><b>Keshav J Raja</b></span></div>
<div>Research Faculty</div>
<div>Center of Ocean-Atmospheric Prediction Studies (COAPS)</div>
<div>Florida State University</div>
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<div><b>NOTE:</b> Please feel free to forward/share this invitation with other groups/disciplines that might be interested in this talk/topic.
<b>All are welcome to attend. </b></div>
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<div><b>https://fsu.zoom.us/j/94273595552 </b></div>
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<div>Meeting # <b>942 7359 5552 </b></div>
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<div>Sep 14th, 2022, Schedule: </div>
<div><span style="margin:0px;background-color:rgb(255, 255, 255)">Colloquium - Attend F2F (in 499 DSL) or Virtually (via Zoom)</span><br>
<span style="margin:0px;background-color:rgb(255, 255, 255)"> </span>* 3:30 to 4:30 PM Eastern Time (US and Canada)</div>
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<div><b>Abstract: </b></div>
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<div>Most high-resolution ocean forecast systems assimilate ocean observations using sequential Data Assimilation (DA). The updates to model state during DA act as a non-physical forcing term in the model equations. Following an update, the model has to undergo
an adjustment to restore its dynamical balance. This adjustment process usually involves inertial oscillations, unrealistic mixing, and some artificial baroclinic and barotropic adjustments. The reduction of the negative impacts of the model adjustment after
assimilation is crucial for the validity of a forecast system. In this talk, we examine the characteristics of a propagating noise in the form of spurious internal waves, generated during the model adjustment after DA in a global ocean model simulation. These
spurious waves are in a broad near-inertial frequency band and can propagate far distances from their generation sites in the form of low-mode waves, rendering the data assimilative model unsuitable for studying high-frequency motions. An ad-hoc solution to
reduce the generation of spurious internal waves during DA will also be presented.</div>
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