Ms. Korita Humphries Taking in the Atmosphere of Seattle
In the eighth grade, I developed a fascination for catastrophic events. And ever since then, I have grown up loving atmospheric science. Therefore, it was only expected that I would pursue this passion in my college career.
I am a rising junior at Claflin University with a science and math background. Though I have been studying my major interests of catastrophic events and climatology on my own, this is my first opportunity to have any hands-on experience that will make a major impact
I was placed under the mentorship of Becky Alexander and one of her graduate students, Eric Sofen. Her major research interests are understanding atmospheric chemistry and how it affects climate change. She works with the oxygen isotopes of sulfate and nitrate in snow pit samples, ice cores, aerosols, and water to determine various aspects of the past atmosphere. One of these aspects is determining the past oxidation capacity of the atmosphere, which controls atmospheric chemistry. It is usually defined by global mean OH concentrations. That is where the oxygen isotopes of sulfate and nitrate come in, as they provide a proxy to these past concentrations. This research breaks down into various facets, only one of which I played a part in.
My research focus this summer was developing the method for the analysis of smaller samples of the capital delta isotope 17 of oxygen (D17O) in sulfate, and then applying this method to snow pit samples from Summit, Greenland. The method involved converting three oxygen isotopes (dubbed Alpha, Beta, and Epsilon) of sodium sulfate (Na2SO4) into the silver form of silver sulfate (Ag2SO4) using the automated method of an Ion Chromatograph system, a cation exchange column, and a fraction collector, and the manual method of a cation exchange resin. Once the sulfate was in silver form, the samples could be dried using a freeze dryer and transferred into quartz capsules. These capsules were then placed in an Isotope Ratio Mass Spectrometer where they are pyrolized at a temperature of 1100 degrees. After which, D17O and sulfate yield analyses could be measured. With my research, the record of D17O values can be extended from around 1680 until the present.
My experience during this internship was been phenomenal. The weekly meetings with my mentor’s research group and with other interns allowed me the opportunity to learn about other efforts in this field and how they are likewise impacting the world. I have bonded with the other interns and, together, we have claimed the city of Seattle, whether it was our canoeing trip or hiking up Mount Rainier. This internship is one I will never forget, with memories I will take back home with me to St. Louis, MO!