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<p class="HTMLBody" align="center" style="text-align:center;line-height:115%"><b><u><span style="font-size:26.0pt;line-height:115%;font-family:"Monotype Corsiva"">Meteorology Seminar<o:p></o:p></span></u></b></p>
<p class="HTMLBody" align="center" style="text-align:center;line-height:115%"><b><span style="font-size:28.0pt;line-height:115%;font-family:"Monotype Corsiva"">Sweta Das</span></b><span style="font-size:28.0pt;line-height:115%;font-family:"Monotype Corsiva""><o:p></o:p></span></p>
<p class="HTMLBody" align="center" style="text-align:center"><span style="font-size:28.0pt;font-family:"Monotype Corsiva"">PhD Meteorology Candidate<o:p></o:p></span></p>
<p class="HTMLBody"><span style="font-size:12.0pt"><o:p> </o:p></span></p>
<p class="doublespacedcaps" align="left" style="text-align:left;line-height:normal">
<b><u><span style="font-size:14.0pt">Title</span></u>:</b> Understanding the evolution of Tropical Cyclones through the streamfunction-velocity potential framework<span style="font-size:12.0pt"><o:p></o:p></span></p>
<p class="doublespacedcaps" align="left" style="text-align:left;line-height:normal">
<o:p> </o:p></p>
<p class="MsoNormal"><b><u><span style="font-size:14.0pt">Major Professor</span></u></b><b><span style="font-size:14.0pt">: Dr. Vasu Misra<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><u><span style="font-size:14.0pt">Co-Advisor:</span></u></b><b><span style="font-size:14.0pt"> Dr. Guosheng Liu</span></b><b><u><span style="font-size:14.0pt;font-family:"Times",serif"><o:p></o:p></span></u></b></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><u><span style="font-size:14.0pt">Date</span></u></b><b><span style="font-size:14.0pt">:</span></b><span style="font-size:14.0pt"> December 5th, 2019
<b><u>Time</u>: 3.30 PM</b></span><span style="font-size:14.0pt;font-family:"Times New Roman",serif"><o:p></o:p></span></p>
<p class="HTMLBody"><b><o:p> </o:p></b></p>
<p class="HTMLBody"><b><u><span style="font-size:14.0pt">Location</span></u></b><b><span style="font-size:14.0pt">:
</span></b><span style="font-size:14.0pt">Werner A. Baum Seminar Room (353 Love Building)<b><o:p></o:p></b></span></p>
<p class="MsoNormal"><b>(Please join us for refreshments served outside room 353 Love @ 3:00 PM)</b><b><span style="font-size:12.0pt"><o:p></o:p></span></b></p>
<p class="MsoNormal" align="center" style="text-align:center"><b><o:p> </o:p></b></p>
<p class="MsoNormal" align="center" style="text-align:center"><b>ABSTRACT<o:p></o:p></b></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-family:"Times New Roman",serif">The understanding of the evolution of a Tropical Cyclone (TC) has been a topic of research for several years.
<span style="color:black;background:white">During the hurricane season not all thunderstorm events embedded in the African easterly waves or otherwise evolve into organized convection with a closed low pressure system, manifesting into TCs. In this work we
suggest that one of the ways to objectively analyze the evolution of the TC is to understand the evolution of the conversion of the available potential energy into kinetic energy on the scale of the disturbance. This
</span>study explores the energetics of the interaction between Streamfunction (Psi</span><!--[if gte msEquation 12]><m:oMath><i><span style='font-family:"Cambria Math",serif'><m:r>: </m:r><m:r>ψ</m:r></span></i></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:3.0pt;mso-text-raise:-3.0pt;mso-fareast-language:EN-US"><img width="18" height="17" style="width:.1875in;height:.177in" id="_x0000_i1025" src="cid:image001.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">)-
Velocity Potential (Chi: </span><!--[if gte msEquation 12]><m:oMath><i><span style='font-family:"Cambria Math",serif'><m:r>χ</m:r></span></i></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:2.5pt;mso-text-raise:-2.5pt;mso-fareast-language:EN-US"><img width="9" height="17" style="width:.0937in;height:.177in" id="_x0000_i1025" src="cid:image002.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">)
in the numerical simulations of the TCs. <o:p></o:p></span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:.5in"><span style="font-family:"Times New Roman",serif">Using the output of separate 48-hour WRF simulations of three Atlantic TCs: Cindy and Irma of 2017, and Michael 2018, we analyze the time history
of the conversion of their kinetic energy from the irrotational to the non-divergent components of the winds. All of these TCs had varied intensities with Cindy being the weakest and Irma being the strongest over the simulation period, which WRF simulated
with reasonable fidelity in the evolution of their peak intensities. We show that at 850hPa, the fractional conversion of the kinetic energy from the irrotational to the non-divergent component of the wind increases as the TC intensifies and is higher for
the stronger TCs than weaker TCs. Contrastingly, in the outflow level of the TC this transfer of kinetic energy is weaker for stronger TCs than the weaker TCs. Our analysis reveals that when the gradients of the streamfunction and velocity potential are large
and oriented parallel to each other both in the large-scale TC environment and in the region of the primary circulation of the TC, then the TC is favored to intensify with robust conversion of the kinetic energy of the irrotational flow</span><!--[if gte msEquation 12]><m:oMath><i><span style='font-family:"Cambria Math",serif'><m:r>(</m:r></span></i><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>χ</m:r></span></i></m:sub></m:sSub><i><span style='font-family:"Cambria Math",serif'><m:r>)</m:r></span></i></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="32" height="19" style="width:.3333in;height:.1979in" id="_x0000_i1025" src="cid:image003.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">
to kinetic energy of non-divergent flow (</span><!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>ψ</m:r></span></i></m:sub></m:sSub></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="22" height="21" style="width:.2291in;height:.2187in" id="_x0000_i1025" src="cid:image004.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">
) at 850hPa. In contrast, however in the outflow layer, we require a slower conversion of
</span><!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>χ</m:r></span></i></m:sub></m:sSub></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="20" height="21" style="width:.2083in;height:.2187in" id="_x0000_i1025" src="cid:image005.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">
to </span><!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>ψ</m:r></span></i></m:sub></m:sSub></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="22" height="21" style="width:.2291in;height:.2187in" id="_x0000_i1025" src="cid:image004.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">
for a TC to intensify otherwise it leads to increased inertial instability and weakening of the TC. We arrive at similar conclusions when we contrast the evolution of the tropical cyclones from its genesis to intensifying stages. Likewise, when we examine
the sensitivity of the simulations of the tropical cyclones to the choice of microphysics, we find that parameterizations that engenders strong conversion of
</span><!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>χ</m:r></span></i></m:sub></m:sSub></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="20" height="21" style="width:.2083in;height:.2187in" id="_x0000_i1025" src="cid:image005.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">
to </span><!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>ψ</m:r></span></i></m:sub></m:sSub></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="22" height="21" style="width:.2291in;height:.2187in" id="_x0000_i1025" src="cid:image004.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">
at 850 hPa and weak conversion of </span><!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>χ</m:r></span></i></m:sub></m:sSub></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="20" height="21" style="width:.2083in;height:.2187in" id="_x0000_i1025" src="cid:image005.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">
to </span><!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><span style='font-size:12.0pt;font-family:"Cambria Math",serif;font-style:italic'><m:ctrlPr></m:ctrlPr></span></m:sSubPr><m:e><i><span style='font-family:"Cambria Math",serif'><m:r> </m:r><m:r>K</m:r></span></i></m:e><m:sub><i><span style='font-family:"Cambria Math",serif'><m:r>ψ</m:r></span></i></m:sub></m:sSub></m:oMath><![endif]--><![if !msEquation]><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;position:relative;top:4.5pt;mso-text-raise:-4.5pt;mso-fareast-language:EN-US"><img width="22" height="21" style="width:.2291in;height:.2187in" id="_x0000_i1025" src="cid:image004.png@01D5AB6D.60B2C050"></span><![endif]><span style="font-family:"Times New Roman",serif">at
the outflow level leads to the simulation of stronger TCs. Therefore, analyzing this conversion rate of kinetic energy of the flow field helps in understanding the evolution of the intensity of TCs.
<span style="color:black"><o:p></o:p></span></span></p>
<p class="MsoNormal" align="center" style="text-align:center"><b><span style="font-family:"Times New Roman",serif"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Shel McGuire<o:p></o:p></p>
<p class="MsoNormal">Florida State University<o:p></o:p></p>
<p class="MsoNormal">Academic Program Specialist<o:p></o:p></p>
<p class="MsoNormal">Department of Earth, Ocean, & Atmospheric Science<o:p></o:p></p>
<p class="MsoNormal">1017 Academic Way, 410 Love Building (Meteorology)<o:p></o:p></p>
<p class="MsoNormal">Tallahassee, FL 32306<o:p></o:p></p>
<p class="MsoNormal">850-644-8582<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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