In this post, I’ve outlined several topics that could serve as the foundation for a M.A. thesis in Geography under my supervision at Minnesota. I don’t intend this list to be exhaustive — students are absolutely encouraged to identify other topics that match their own interests and expertise. But based on our past experience, those independent topics should be planned to (a) involve a similar effort to the ones listed here and (b) should connect in some way to past or ongoing research conducted by the members of our group.
An atlas of frost rings in North America
Prerequisites Introductory Statistics; GIS
Methods Literature review; Monte Carlo analysis; Cartography
Description Unseasonably cold weather during the growing season can cause trees to form ‘frost rings’, which are the most common type of anatomical abnormalities present in tree-ring records. Frost rings have been reported at dozens of forest stands across North America (likely more), and are often interpreted as evidence of cold conditions triggered by volcanic eruptions. The aim of this thesis is to conduct a comprehensive survey of frost rings reported in the literature and construct a yearly atlas of frost rings during the last millennium and earlier.
Searching for evidence of solar cycles in tree rings
Prerequisites Statistics; GIS
Methods Spectral analysis; Dendroclimatology; Monte Carlo simulations
Description The solar cycle is a nearly-periodic 11-year change in the Sun’s activity and appearance that has been observed for centuries. Some researchers have argued that the 11-year cycle is also evidence in climate proxies such as lake sediments and tree rings, but other scientists complain that those studies are plagued by incorrect reasoning and poor statistical methods. This project will examine the Northern Hemisphere tree-ring width record to determine whether or not the sunspot cycle has had discernible effect on tree-growth, either locally or globally, during the past several centuries. This project would involve collaboration with Dr. Richard Telford at the University of Bergen (Norway).
Extreme paleofloods and flood risk assessments
Prerequisites Geomorphology; Statistics; Hydrology
Methods Literature review; data visualization; extreme value analysis
Description Floods are consistently the most damaging natural hazard, and our understanding of future flood risks is almost always based on our knowledge of past floods. Because extreme floods are rare by definition, the relatively short instrumental record of hydrological extremes can sometimes underestimate the true magnitude of the largest events. This thesis will identify cases where paleofloods are estimated as larger than the current flood-of-record (as estimates from instrumental gage records), and evaluate the influence of those exceptional paleofloods on flood risk assessments. This thesis will primarily focus on case studies in North America, but could be expanded to include one or more additional geographical areas.
Evaluating sonification as a tool for climate science education
Prerequisites Statistics; GIS
Methods Sonification; Educational psychology
Description The main findings of climate science are usually communicated to the public as data-rich visualizations, but the complexity of those representations might serve as a barrier to the public understanding of climate science. Sonifications — the transformation of data into sound — offer an alternative method to convey climate science, particularly when musical elements are introduced to make the compositions sound more like music. In this project, the thesis will apply techniques from educational psychology to test the effects of climate sonifications as learning tools.
Wind drought over the past millennium
Prerequisites Statistics; R/Matlab; Interest to work with large datasets
Methods Principal components analysis; extreme value analysis
Description Prolonged intervals of weak surface winds (‘wind droughts’) act to reduce energy generated from wind turbines, but the long-term behavior of these rare events are not well understood. In this thesis, the student will analyze output from the Last Millennium climate simulations to determine whether or not the range of variability exhibited by surface winds in North America during the last few decades is representative of its long-term behavior. The thesis will identify any areas in North American that might be prone to exceptionally long-lasting decreases in wind strength (‘mega-wind droughts’) and evaluate the relative effects of forced and stochastic variability on yearly or decadal trends in surface wind speeds.
Dating historical structures in the Red River basin
Prerequisites Dendrochronology; Wood anatomy
Methods Tree-ring dating; Wood anatomical measurements
Description Modern forests in the Red River basin (including western Minnesota and eastern North Dakota) rarely have trees older than 150 years, so timbers from buildings or archeological sites is crucial to develop long tree-ring records for paleoclimatic reconstruction and dating pre-modern material. This thesis will use dendrochronological techniques to date historic timbers or archeological specimens collected across this region. At the same time, the project will identify any marker years or anatomical anomalies that can be used as an aid to dating and to establish multi-century long records of environmental disturbances. This project will involve close collaboration with Dr. Joe Zeleznik (North Dakota State University) and some travel to Fargo and other locations in the basin.
Air travel times and seasonal (or longer) climate variability
Prerequisites Climatology; Statistics;
Methods Matlab/R/Python; Statistical Analysis; Weather Reanalysis
Description Previous work done by our group has shown that travel times (specifically delta T, the time difference in flights going to-and-from pairs of airports) is strongly affected by climate variability at the seasonal scale and longer. In this thesis, the student will extract data from the national flight database, compute delta T for paired sets of airports across the USA, and identify specific air routes where travel times vary substantially during the last several decades. The student will also evaluate how delta T is (or is not) connected to upper-air circulation over North America and may be influenced by major climate trends, anomalies, and modes.