The Japanese Swedish Antarctic Expedition 2007/08 Shuji Fujita 1*) , Per Holmlund 2) , Kumiko Azuma 1) , Masanori Chiba 1) , Hiroyuki Enomoto 3) , Yoshiyuki Fujii 1) , Koji Fujita 4) , Kotaro Fukui 1) , Margaretta Hanson 2) , Keiichoro Hara 5) , Ulf Hedman 6) , Yoshinori Iizuka 7) , Satoshi Imura 1) , Kenji Ishizawa 1) , Hideaki Motoyama 1) , Fumio Nakazawa 1) , Johan Ström 8) , Shin Sugiyama 7) , Sylviane Surdyk 8) 1) National Institute of Polar Research, Research Organization of Information and Systems(ROIS), Japan, 2) Department of Physical Geography and Quaternary Geology, Stockholm University, Sweden, 3) Kitami Institute of Technology, Japan, 4) Nagoya University, Japan, 5) Fukuoka University, Japan, 6) Swedish Polar Secretariat, Sweden, 7) Institute of Low Temperature Science, Hokkaido University, 8) Department of Applied Environmental Science, Stockholm University, Sweden, 9) Surdyk Scientific, Japan * Corresponding author: sfujita@pmg.nipr.ac.jp Abstract We will perform a research expedition to investigate ice sheet environment in inland of East Antarctica in the austral summer 2007/08. The main objectives of the expedition are to better understand the interior of Antarctica by means of climate, physical, chemical and biological investigations, and to study the special environments associated with subglacial lakes. By theses purposes, we will particularly focus on various sampling and monitoring over wide area. The survey area will be a 3000-km-long traverse route in total, covering area between the Japanese Syowa station and the Swedish Wasa station, through two the deep ice coring sites at Dome Fuji and Kohnen. The scientific planning and the expedition is a collaborative effort of members from several institutions and laboratories in Japan and Sweden. Major sampling plan includes snow sampling for physical, chemical and biological analyses and aerosol sampling. Also, major measurements include meteorological observations, subsurface radar sounding, microwave remote sensing and GPS measurements. 1. Introduction Even nowadays, inland of the Antarctic ice sheet is so remote and it does now allow us easy access. It remains as one of scientific frontiers on the earth surface. There are many important scientific subjects to be extensively explored. One of them is climatic signals. Today we know that the Antarctic ice sheet holds unique information of the earth systems and past climate changes. Such information is preserved in the ice sheet as strata of deposited snow and deposited frost. Climatic information is recovered as snow/ice core samples of various length scales and age scales. In addition, we know that if snow/ice cores are sampled from many locations in Antarctica, we can get knowledge of spatial variations of climate changes. Moreover, surface processes of aerosol, snow and firn are fundamentally important to link between atmosphere and ice core signals. Therefore, "climate" gives us one of strong motivation to explore wide area of Antarctic inland. There are many other major scientific topics. Using radar sounders we can map distribution of the strata, that is, constant time horizons in the ice sheet. Extensive radar surveys can clarify past accumulation rate and its spatial variations. In addition, by radar survey we can link two or more ice cores that are drilled at remote locations with each other. Radars generally clarify englacial and subglacial environments as scattering signals of electromagnetic waves. A strong benefit of ground-based radar survey is that we can get higher quality data from deeper inside of the ice sheet, compared with the airborne radar data. In addition, previous radar works have discovered that there are so many subglacial lakes in Antarctica (e.g. Popov and others, in press; Siegert and others 2005). Radar sounders are again one of powerful tools to investigate physical conditions of the lakes that are below a few thousand meters thick ice sheet. Subglacial lakes are important not only to understand the glaciological/hydrological systems but also to explore eco systems in an environment that is covered over as long as thirty million years. By