As key components of freshwater (lake and river), estuarine and nearshore marine aquatic environments of the circumpolar north, Arctic char and related fishes of the genus Salvelinus are fundamental to the lifestyles and well-being of northerners as the basis for extensive fisheries conducted for household food (i.e., domestic and subsistence), commercial and sport purposes. Chars contribute significantly to household and wage economies, and social and cultural elements of northern life. Chars are also key integrators and indicators of the health of northern aquatic ecosystems, many aspects of which are at significant risk from increased climate variability and change. However, human adaptive responses are hampered by a lack of vital information regarding char thermal ecology, biodiversity and its functional significance in northern ecosystems, mercury and other pollutant interactions, and how these may respond to climate change.

Even though climate change is dramatically affecting the biosphere, our understanding of its effects on biological communities is poor. The Southern Ocean is an ideal natural laboratory to the impact of regional and global climate change because of the sensitive interactions between temperature, ice extent and species. Measuring variations in penguin populations can tell us a great deal about climate change, but could tell us even more if we understood the mechanisms the underlie the dynamics of penguin colonies. Taking advantage the major advances that have been made in microelectronics recently, this project will fit penguins with hugely powerful yet tiny state-of-the-art transponders and data recorders. The project will provide the first complete global and unified picture of penguin population dynamics, uncovering the processes that drive their numbers and the effects climate change is having on them.

The polar environments are rapidly changing and leaving a lasting impact on the freshwater and terrestrial ecosystems within them. However the region is so vast and diverse that the knowledge of what drives these changes is limited. This project will assess how terrestrial and freshwater ecosystems and environments have changed in the past and record their current status and biodiversity. IPY provides a timely opportunity for passing on knowledge to new generations of researchers and forming a new and authoritative baseline of environmental characteristics with which to examine future changes. Among the sites to be studied are some first examined during the ICSU-sponsored International Biological Programme, which will allow some assessment of changes over recent decades.

POLENET will deploy an ambitious array of geophysical instruments across the polar regions in order to study the complex interplay between climate, ice sheets, geodynamics, and global sea level change. POLENET geodetic and seismic observations, paired with other types of geophysical measurements, will greatly improve our understanding of high latitude Earth systems. This international collaboration of 24 countries will involve scientists, students and educators at all levels, and will further advance our capability to deploy autonomous instruments in extreme environments

Antarctica is the primary heat sink in the global climate system: it plays an important role in climate change and variability, and Antarctic atmospheric processes affect the rest of the planet via the atmosphere and the sea. Using satellites and the state-of-the-art HIAPER research aircraft, AC Squared will help scientists gain a better understanding of how these processes work – knowledge that is essential if we are to develop models that more accurately predict global climate change.

The proposed activity aims at establishing a bipolar network to obtain data needed to quantify properties of aerosols at high latitudes, including seasonal background concentrations by measurements of aerosol optical depth (AOD), spectral characterizations, and the evolutionary patterns of the natural and anthropogenic processes that perturb the aerosol cycles. An effort to quantify direct and indirect climate forcing by polar aerosols will be made through a set of closure experiments using observations in conjunction with model calculation and satellite data.