- Projects in the Climate-Ocean-Atmosphere Program (COAP)
- Projects in the Geosciences of the Earth, Oceans, and Planets Program (GEO)
- Projects in the Ocean Biosciences Program (OBP)
Twomey Effect Research
Dr. Lynn Russell
The underlying physical principle of cloud albedo modification by aerosol particles is typically identified as the Twomey effect (1970) and can be predicted from the microphysical behavior described by Kohler (1921). These basic physics state that if more particles are large enough (or hygroscopic enough) to nucleate to droplets in a cloud of a given supersaturation, without substantially changing the total available water or temperature, the resulting clouds contain more droplets of smaller average diameter. This larger number of smaller cloud droplets increases the reflectance of clouds, so that more sunlight is reflected back to space without increasing the temperature of the Earth system. Cargo ships transiting the Pacific provide frequent satellite-observed "tracks" that have increased reflectance associated with aerosol effects on clouds. This emissions-induced increased reflectance has been suggested as a method to engineer an offset to global warming, but substantial evidence indicates that scaling up this effect does not account for the observed variability in cloud structure and feedbacks. This project will review and compile observations to assess the characteristics that differentiate clouds that form "tracks" from those that do not.
Marine Bioacoustics Lab
Dr. Ana Sirovic
The Marine Bioacoustics Lab offers multiple opportunities for Master's projects in the field of acoustics. In one potential project, the student would be working on the investigations of long-term trends in ocean ambient noise from passive acoustic recordings collected across the Pacific Ocean. We are particularly interested in the contributions of anthropogenic sounds to the overall noise trends. In a different project, the student would develop algorithms for automatic detection of blue whale D calls, for effective analysis of long-term passive acoustic data. The algorithm could then be applied to a variety of data sets from the Pacific, Atlantic, and Southern Oceans. Interested students should apply to the Climate-Ocean-Atmosphere program. For more information, visit the Marine Bioacoustics Lab website (http://sirovic.ucsd.edu) or email Dr. Širović (email@example.com).
Tracking Ocean Noise and the Source of Earth's Hum
Dr. Gabi Laske
It has long been recognized that planet Earth rings with characteristic frequencies, Earth's normal modes, after very large earthquakes. More recently, however, some of these modes have been discovered in seismic records even at times with no great earthquake. This aseismic activity is known as Earth's hum. After initial searches for a cause in atmospheric processes, evidence is mounting that ocean processes are more effective at coupling energy into the solid earth. It has been suggested that large winter storms in the northern Pacific Ocean that enhance signal in the microseism band at a period of 5 s also enhance signal in the infra-gravity band at periods below 100 s, the band relevant for this project. From 2005 through 2007, our Plume-Lithopshere Undersea Mantle Experiment (PLUME) collected a unique large seismic dataset on ocean bottom seismometers (OBSs). We seek a masters student to participate in this project to search for and analyze significant ocean events that could potentially excite Earth's hum.
Dr. Lynn Russell
As biofuel becomes available for more applications, its emissions will contribute more to both background pollution and to urban areas. In this project, we will use shipboard measurements of gas and particle concentrations to compare how fuel switching may affect both air quality and climate.
Computational Geodynamics; Seismology
Dr. Dave Stegman
This project is focused on understanding the seismic anisotropy observed underneath western North America. This is one part of a larger collaboration that has successfully developed geodynamic models of the mantle dynamics under western North America since the past 40 Myr. These predicted mantle flow fields will be used to calculate synthetic shearwave splitting delay times by propagating synthetic seismic waves through the anistropic mantle fabric that self-consistently develops from the deformation history associated with the non-steady-state mantle flow fields that are generated. These models will generate predictions of delay times by using the full time histories of predicted mantle flow fields under the western US (from 40 Ma to present). The predicted shear wave splitting measurements will be directly comparable to observations.
Dr. Lisa Tauxe
The magnetic field is constantly changing and has been dropping at an alarming rate over the last century at least. Whether to predict collapse and possible reversal depends on its behavior in the past. Yet what is the average magnetic field strength over time and its variation are still poorly known. For example, some have predicted that average field strength is related to the length of time without a reversal. One very long time with no reversals (~40 million years) occurred in the Cretaceous and there is still much debate about what the average field strength was during that time. The igneous intrusion directly to the East of San Diego was emplaced during the Cretaceous and may have an ideal record of the field during that time. This project will sample the rocks exposed within an hour’s drive of San Diego and subject them to the paleointensity experiment in the SIO paleomagnetic laboratory. The results will provide clues to the long term behavior of the magnetic field and likely will result in a publishable paper. For more information, email Prof. Lisa Tauxe (firstname.lastname@example.org).
Dr. Doug Bartlett
We are studying deep trench and hydrothermal vent-associated extremophjilic microorganisms at multiple levels ranging from diversity to genomics to adaptations to high pressure. M.S. thesis project possibilities include isolating, characterizing and describing new species, analyzing the genomes of uncultured deep-trench microorganisms, and performing analyses aimed at identifying genes required for high pressure growth. Although opportunities may exist for participation in research cruises, the essence of the thesis experience will involve intensive laboratory-based investigation. Students with experience in microbiology and/or bioinformatics are encouraged to apply.
Dr. Jennifer Taylor
The Taylor lab studies invertebrate biomechanics- how are animals built to live in different environments and perform important behaviors. We primarily explore the link between the structure, mechanical properties, and function of the crustacean exoskeleton, and how these characteristics are influenced by the environment. Potential M.S. thesis projects include studying the skeleton of Southern California crustacean species, using scanning electron microscopy, materials testing, and behavioral experimentation. Interested students should apply to the Ocean Biosciences Program and contact Dr. Jennifer Taylor at email@example.com.