Chinese expedition team launched its fourth North Pole expedition on July 1, 2010 aboard a Snow Dragon boat. During the expedition, Chinese scientists will mainly work on two topics: fast changing sea ice circling the North Pole and associated mechanism, and the response of the North Pole marine ecosystem to the fast changing sea ice. The expedition team is made up of the scientists from more than 20 domestic research institutes, and 6 foreign scientists invited from the United States, France, Estonia, and the Republic of Korea, or 122 members in total. The expedition team will return to Shanghai on September 23, 2010, after an 85-day journey, the longest trip with the largest team in China's North Pole expedition history.