Turbulent Boundary Layers in the Atmosphere and Ocean
7.5 credits cr.
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The boundary layer is our home and is the layer above the earth surface with about 1km depth. Most transport and mixing processes of heat, momentum in addition to water vapour and pollutant take place in this layer. It is therefore of crucial importance to study and understand the dynamical processes involved.
The boundary layer course deals with dynamical processes involved in the atmospheric and oceanic boundary layer. The course presents the turbulent nature of the atmosphere/ocean in the boundary layer, which acts to mix and transport heat and momentum, water vapour and pollutant. The course equip the students with the required knowledge to solve problems related to transport and mixing in the boundary layer.
The course is composed of a mixture of theory and practical. The practical is composed of two lab sessions. one relating to onsite measurements and the other relates to numerical modelling. The course therefore enables students to measure turbulent quantities in the boundary layer and also to engage in using computer models to analyse boundary layer turbulence.
The course opens the possibility to students to work with research groups working on the boundary layer in universities or forecasting centres. It also gives them a unique opportunity to work with organization and companies working on pollution and air quality.
The boundary layer is the layer where we live, and it is therefore important to study the processes of transport and mixing involved. The course provides the tool and the means to engage in studying the boundary layer. The process of heat, momentum and water exchange in the boundary layer is described using turbulence and similarity theory. Students with background in Atmospheric Physics and Chemistry (MO4000), Meteorology I (MO8001), and Meteorology II (MO8002), can easily follow the course. The course starts with a description of the observed structure of the boundary layer, then introduces the concept of Reynolds decomposition, a basic assumption in turbulence theory. Turbulent energy and turbulent fluxes are then discussed, leading to the closure problem. Similarity, e.g. Monin-Obukov theory is then introduced to get the equations of turbulence. Measurements are then used for fitting the fluxes obtained from similarity theory. To link the boundary layer to the free atmosphere above, the course also presents a topic on the circulation in the boundary layer, i.e. the Ekman layer. The course then ends with the dispersion, which deals with pollution transport and mixing.
The course is composed of lectures, slides presentation, tutorials and lab projects. The white board lectures present the theory of boundary layer turbulence, while the powerpoint presentations show results obtained from experiments and applications from numerical models.
To assimilate the theory, the lectures are complemented with tutorials in the form of corrected exercises. The lab projects consist of two lab sessions. The first lab consists of onsite measurement of turbulence, and enables the students to experiment with instruments and measure momentum fluxes, which are then analysed, written and presented orally. The second lab is on numerical modeling the boundary layer and enables the students to work with a simplified numerical model to simulate boundary layer processes. Both labs lead to two written reports, and oral presentations.
Grading criteria, course literature and other material and correspondence related to the course will be available on the course Athena-site at https://athena.itslearning.com once you have registered for the course.
The examination is done by a written exam covering the course content. The pass grade is 50%, and the grades are presented according to 7 scales: A (excellent), B (very good), C (good), D (satisfactory), E sufficient, Fx (failed, and some more work is required – e.g. oral examination), and F (fail). The written reports of the two labs and the oral presentations are graded as pass or fail. To pass the whole course the students need to pass both the written exam and the lab reports.
Here is a link to a list of examiners for 2020:
ScheduleThe schedule will be available no later than one month before the start of the course. We do not recommend print-outs as changes can occur. At the start of the course, your department will advise where you can find your schedule during the course.
Course literatureNote that the course literature can be changed up to two months before the start of the course.
- Garratt, J. R., 1992: The Atmospheric Boundary Layer. Cambridge Atmosphere and Space Science Series, Cambridge, Cambridge University Press.
- Holton, J., and G. Hakim, 2013: An Introduction to Dynamic Meteorology. Academic Press.
The course is held every autumn semester.