"during the second International Polar Year"

International Polar Year is a scientific programme focused on issues pertaining to the Arctic and the Antarctic. The word "Year" is actually quite misleading, as it is neither a regular nor an isolated event: since the first International Polar Year in 1882-83, there have been three subsequent programmes, in 1932-33 (as mentioned in the book), 1957-58 and 2007-08. Each programme included numerous research projects, seminars, conferences and trips related to particular fields of interest within  the Polar world.