Rényi entropy and finite Lyapunov exponents as metrics of transport and mixing in an idealised stratosphere

dc.contributor.authorGrahn, Jakob
dc.contributor.departmentChalmers tekniska högskola / Institutionen för rymd- och geovetenskapsv
dc.contributor.departmentChalmers University of Technology / Department of Earth and Space Sciencesen
dc.date.accessioned2019-07-03T12:59:26Z
dc.date.available2019-07-03T12:59:26Z
dc.date.issued2012
dc.description.abstractMost numerical metrics for diagnosing transport and mixing in fluid flows are based on calculating trajectories and thus knowing the velocity fields of the flows. Velocity fields are however difficult to measure globally on Earth. Tracer fields are on the other hand easier to measure and tracer based metrics could therefore prove to be valuable. A newly proposed metric based on the Rényi entropy of tracer values is examined. Although the metric has been used before, the exact theoretical connection to transport and mixing appears to be unclear to us. This motivates us to examine the metric under controlled circumstances. A simple model, defined by only a few parameters, is implemented and used as a test bench for comparing the metric with conventional trajectory based metrics. In particular, the finite time and the finite size Lyapunov exponents are considered for the comparison. We show that the Rényi entropy metric features the main transport barriers of the model and a positive correlation to the finite Lyapunov exponents is found.
dc.identifier.urihttps://hdl.handle.net/20.500.12380/163109
dc.language.isoeng
dc.setspec.uppsokLifeEarthScience
dc.subjectGrundläggande vetenskaper
dc.subjectGeovetenskap och miljövetenskap
dc.subjectBasic Sciences
dc.subjectEarth and Related Environmental Sciences
dc.titleRényi entropy and finite Lyapunov exponents as metrics of transport and mixing in an idealised stratosphere
dc.type.degreeExamensarbete för masterexamensv
dc.type.degreeMaster Thesisen
dc.type.uppsokH
Ladda ner
Original bundle
Visar 1 - 1 av 1
Hämtar...
Bild (thumbnail)
Namn:
163109.pdf
Storlek:
6.21 MB
Format:
Adobe Portable Document Format
Beskrivning:
Fulltext