Polonium-210 Inventory in the World’s Ocean

Offered By: Gillian Stewart, Associate Professor, School of Earth and Environmental Science, Queens College

Subject Area: Natural Science, Oceanography, Biogeochemistry

Duration: 9/17/2012-1/21/2013, 8 hours per week

Location:  New Science Building, Queens College

Project Background: The lab measures polonium-210 and lead-210 in seawater and particulate samples in order to understand the cycle of bio-reactive elements in the surface ocean. Specifically, I am interested in tracing the carbon cycle and the role that organisms play in sequestering carbon into the ocean from the atmosphere.

Very few papers about 210Po and 210Pb in the ocean have been published. The field only started in the early 1970’s and to date there has not been a summary or review of all the available literature. I would like to write a review paper on the water column profiles of polonium in the ocean, and compare and contrast various ocean basins.

Description: There are two aspects of this project and I would like one student to work on the literature search and data entry side, and the other to work on the chemistry and analytical side.

One student (ideally with a background in chemistry) will be involved in the wet chemistry of digesting and analyzing natural samples. This student would spend about 8 hours a week in the lab.The digestion process involves a series of steps where the sample is heated in different mineral acids until complete digestion has been achieved. Then, the samples are plated onto silver planchets and the alpha radiation is measured in a spectrometer. The samples need to be plated and counted twice before we can calculate the concentration of 210Po and 210Pb in the sample. This student would also be expected to help with making solutions and cleaning glassware involved in these analyses.

The other student (ideally one who is familiar with reading scientific literature and data entry), would spend much of his/her time outside of the lab, but would need to be very organized and thorough. This student would search through all of the available literature on polonium in the ocean (I would provide a list of publications to start) and would collect the relevant raw data on Po concentration and fractionation (between dissolved and particulate phase) into a master spreadsheet that could be searched by author, ocean basin, depth, etc. This student would need to be comfortable reading some very difficult papers and would need a good grasp of geography and unit conversions.

Specific skills, background, majors preferred: One student should be comfortable in the lab, be familiar with lab safety, and be very careful around toxic substances (both acid and low levels of radiation). The other student should be self-disciplined to work outside of the lab, comfortable doing literature and reference searches and be familiar with large data-sets and data organization. These students should be able to commit 8 hours every week to this project and should be able to attend an additional lab meeting once every month. The students will be expected to speak about their work to the lab group.

Additional information: The students will also be working with graduate students and a lab manager, and should be confident working independently, but comfortable with team-work. The students should expect guidance for the first month or so, and after that should be able to continue working on their own (but ALWAYS ask for help when needed).

If students work well in the lab and are responsible and diligent, they can discuss the possibility of a paid position in the future. I expect that anyone who works in my lab will want a letter of recommendation at the end of the project, and I will be happy to provide advice and guidance on graduate school options and future careers in science.

Click here for guidelines and application instructions for the Macaulay Research Assistantship Program. Please review before applying.

Note: This position is closed.