A Rutgers scientist recounts her four-month research journey to the Southern Ocean and Antarctica
Last November, I joined a research cruise onboard the Chinese icebreaker, Xue Long, a huge vessel – 167 meters long, 22.6 meters beam, with a full-loaded displacement of 21,250 tons. The purpose of my trip was to measure the atmospheric nutrients and aerosols over the Southern Ocean, which surrounds Antarctica and plays an important role in regulating the global carbon cycle and climate.
Our work, sponsored by the U.S. National Science Foundation’s Antarctic Atmosphere and Ocean Program, was carried out through a joint U.S.-China international research collaboration. The voyage is China’s 27th Antarctic expedition, with about 150 people from different Chinese institutions onboard the Xue Long; Rutgers was the only foreign institution participating on the cruise.
The Xue Long (the name means Snow Dragon) departed from Shanghai, China in early November 2010 and sailed south through the Southern Ocean, reaching Antarctica the following month. The ship sailed around the Antarctic seas before her return leg to China in March, harboring at her home destination, Shanghai, China, on April 1.
One research focus of mine is to study the properties of atmospheric iron (Fe) over the Southern Ocean, a high-nutrient-low-chlorophyll region in the global ocean, where the growth of marine phytoplankton is limited by the supply of micronutrient Fe. Among the sources of Fe in the Southern Ocean is atmospheric dust that travels from the continents. But the uptake of Fe by phytoplankton depends on the properties of atmospheric Fe, in particular Fe bioavailability, which is the portion of Fe that can be taken up by marine organisms and a process that is poorly understood.
At present, the Southern Ocean is extremely under sampled due to its vast area and poor atmospheric conditions, which include high winds and sea spray, high cloud coverage, and low dust loading in the atmosphere.
One of our biggest challenges during our voyage was to work on deck while the ship went through the band of strong westerly winds in the Southern Ocean, the region with the biggest waves in the global oceans, frequently under the impacts of strong cyclones. We encountered wind speeds in excess of 25 m/s (60 mph), and the ship would often rock sideways at more than 12 degrees. Sea water would splash up to the ship’s eighth floor deck where our atmospheric platform was erected and our instruments installed. Nevertheless, we managed to get our samplers running and samples collected. As soon as the ship reached the floating ice zone near Antarctica, it became more stable and we were able to run chemical analyses in the lab that I hope provide further insights into atmospheric Fe processes and the atmosphere-marine ecosystem interactions in the Southern Ocean.
In addition to carrying out shipboard atmospheric measurements, I was able to spend time at China’s Antarctic Zhong Shan Station for aerosol sampling. I also visited Australia’s Antarctic Casey and Davis Stations. At Casey, I even practiced the release of a weather balloon that could go up to ~30km height! Through these activities I learned about the unique research efforts in Antarctica made by China and Australia.
As the only American professor onboard, I shared my thoughts with many young people who are interested in studying in America, and the cruise gave me the unique chance to get to know more international students. At the same time, I had a wonderful time meeting many people from different fields and to develop long-lasting friendships with them.
Now that I am back at Rutgers, I feel much stronger compared to when I first left last November – after almost 4 months at sea, I am no longer afraid of seasickness, although occasionally when I sleep, I still feel I am on the Xue Long, rising up and down, drafting around. Going through the vast Southern Ocean and visiting Antarctica has been a unique experience. Our work is among the first efforts exploring bioavailable Fe in the atmosphere over the Southern Ocean, and our data are critically needed for better understanding of the atmospheric processes and of the ocean biogeochemical cycles in the region, contributing to the interdisciplinary sciences. On the other hand, I have seen the precious Antarctic landscapes and snow-covered natural beauty, and I now have a better understanding of how important it is to appreciate and preserve the nature and wildlife on our planet.