The International Polar Year (IPY) 2007-2009

The Polar Regions have profound significance for the Earth's climate and ultimately environments, ecosystems and human society. However we still know remarkably little about many aspects of the polar climate and its interaction with polar environments, ecosystems and societies. We do know that the three fastest warming regions on the planet in the last two decades have been Alaska, Siberia and parts of the Antarctic Peninsula, showing us that the Polar Regions are highly sensitive to climate change. This raises real concern for the future of polar ecosystems and Arctic society.

There have been a number of major international science initiatives in Polar Regions since the first International Polar Year in 1882-83. These initiatives involved an intense period of interdisciplinary research, collecting a broad range of measurements that provide a snapshot in time of the state of the polar regions. The last such initiative was the International Geophysical Year in 1957-58. Fifty years on, technological developments such as earth observation satellites, autonomous vehicles and molecular biology techniques offer enormous opportunities for a further quantum step upwards in our understanding of polar systems, and hence IPY 2007-2008 was initiated. To ensure that researchers get the opportunity to work in both polar regions or work summer and winter if they wish, the Polar Year will actually run from March 2007-March 2009.

The Dutch contribution to the IPY

There are several reasons for the Netherlands to participate in the IPY. Several of the IPY research themes are of physical, economical and political importance to the Dutch government, such as international treaties, sea level rise, climate change, innovation and energy production. Since present state of knowledge about the polar regions is still insufficient to answer all raised questions the International Polar Year provides an excelent opportunity to extend our knowledge. Furthermore, the international nature of the IPY offers the opportunity for Dutch research groups to participate in large international projects. The Dutch contribution to the IPY 2007-2008 focusses on four main themes:

  1. Changes in the cryosphere caused by climate change.
  2. Changes in the Southern and Arctic Oceans caused by climate change and due to antropogenic sources.
  3. Interaction between the ecosystems of polar terrestrial and coastal zones and global change.
  4. Influence of human activities on the polar regions and the impact of climate change on humans.

Theme Ice, Climate and Sea Level Change

The mass budget of glaciers (the common name for valley glaciers, ice caps and ice sheets) basically has three components: accumulation, ablation and iceberg calving. The balance between accumulation and ablation areas is restored through the flow of solid ice, which governs the dynamical response of the glacier to a change in its mass budget. A glacier that is not in balance with the ambient climate looses/gains mass and thereby raises/lowers global sea level. It is estimated that the total volume of land ice in the Arctic corresponds to a sea level equivalent of 8 m, 85% of which is accounted for by the Greenland ice sheet (GrIS). Recent observational data show a generally consistent picture of cryospheric change in the Arctic in response to higher atmospheric and oceanic temperatures, with decreasing sea ice and seasonal snow cover, increasing river discharge and increasing permafrost temperatures. Glaciers throughout the northern hemisphere have lost mass over the past several decades, as have the margins of the GrIS, contributing 0.15 to 0.30 mm per year to global sea level rise. In 2005, melting at the surface of the GrIS reached a new record high (Link) and sea ice extent was at a record low. In response to warming and decreased snowfall, Arctic glaciers have been thinning and retreated to higher grounds, while snowfall has increased over the interior of the GrIS, as suggested by models and satellite radar altimetry.

In addition to these changes, evidence is mounting that Arctic glaciers and the GrIS are capable of reacting much faster to changes in their surface mass balance than previously assumed. After a decade of warm summers, Arctic glaciers have been rapidly accelerating and/or thinning. The recent massive losses from Greenland's Jakobshavn Isbrae, the fastest glacier in the northern hemisphere, were probably initiated by the disintegration of its floating ice tongue and possibly similar to recent disintegration of floating ice shelves in the Antarctic Peninsula. But other Arctic glaciers without floating ice tongues have also accelerated and thinned; these glaciers may have experienced enhanced basal lubrication as a result of an increased flux of surface melt water that has drained to the bed. While periodic thinning is normal for individual glaciers, for glaciers that are far apart to show a simultaneous thinning requires external forcing. Understanding and being able to model and predict these changes and identifying the external forcings is very important, because the positive feedback (surface melting -> faster flow -> thinning and surface lowering -> more melting) could lead to a collapse of Arctic glaciers and the GrIS that is much faster than has been assumed so far. Recent evidence from fossil coral reef dating show that past sea level changes were up to ten times faster than the present rate of change, even during periods of seemingly stable orbital forcing. These rapid sea level changes are caused by variations in global ice volume, but the origin of the ice (Greenland, West Antarctica?) remains unknown.

Clearly, if we want to be able to predict future changes in the mass balance of Arctic glaciers, we must first understand its dynamical behaviour in the past. Recent deep ice core drilling projects such as GRIP/GISP in the 1990s and the recently finalized North Greenland Ice coring Project have revealed a wealth of information on Eemian climate and atmospheric greenhouse gas concentrations, including the second most important greenhouse gas methane. An important benchmark is the previous interglacial, the Eemian. The Eemian was several degrees warmer than today's climate and could serve as an analogue for a future greenhouse climate. An important question therefore pertains to the size and shape of the GrIS during the Eemian.

Given the enormous investments required to maintain safety levels when mass loss from Arctic glaciers increases and sea-level rise accelerates, it is clear that research on this topic must be intensified. The IPY offers a unique opportunity for this. This website describes a coordinated Netherlands research effort to the IPY on the mass budget of Arctic glaciers, with special reference to the Greenland ice sheet, and their dynamical response to climate change.


The IMAU contribution to the Dutch and international IPY effort is organised in the project "Arctic glaciers, climate and sea level change". This project consists of several sub-projects:

  • Meltwater input, flow and calving of Arctic glaciers
  • Regional modelling of Greenland surface mass balance for key episodes in the past and future

The first project focusses on the relation between melt water production and glacier velocities by using low cost GPS systems to observe glacier velocities at an extended amount of locations on Arctic glaciers in combination with an extensive mass balance study of the same glaciers. The second project uses an regional climate model to study the mass balance of the Greenland ice sheet in the last glacial maximum and the Eemian.

In addition, as part of IPY two low-temperature automatic weather stations (AWS's) will be placed in the interior of East Antarctica in order to study the climate of very remote region of our planet.

Summary (in Dutch)

Gletsjers en ijskappen in het Noordpoolgebied bevatten voldoende water om wereldwijd de zeespiegel met 8 m te laten stijgen. Deze gletsjers hebben de afgelopen decennia significante hoeveelheden massa verloren als gevolg van het warmer worden van de noordelijke atmosfeer en de oceaan (zie het ACIA rapport). Hiermee dragen ze in belangrijke bij aan de huidige wereldwijde zeespiegelstijging van 2 mm per jaar. Recent onderzoek toont aan dat smeltwater dat aan het oppervlak van de gletsjers is gevormd via subglaciale kanalen een weg vindt naar de onderkant van de gletsjer. Hierdoor gaat de gletsjer sneller stromen, waardoor deze dunner wordt, het oppervlak lager komt te liggen, er weer meer afsmelt, enzovoort. Door deze positieve terugkoppeling kunnen zelfs grote ijsmassa's zoals de Groenlandse ijskap onverwacht snel reageren op klimaatveranderingen. In dit onderzoeksprogramma zal een robuust model voor dit mechanisme worden ontwikkeld waardoor we het verleden en de toekomst van arctische gletsjers, inclusief de Groenlandse ijskap, beter kunnen nabootsen en voorspellen. Daartoe zullen we uitgebreide systematische metingen gaan uitvoeren van ijssnelheden en de hoeveelheid beschikbaar smeltwater op vijf Arctische gletsjers. Een andere belangrijke vraag is hoe de Groenlandse ijskap eruit zag gedurende het vorige interglaciaal (Eem). Het Eem was enkele graden warmer dan het huidige interglaciaal, en zou kunnen dienen als analogie van ons eigen toekomstige broeikasklimaat. Een belangrijke randvoorwaarde voor ijskapmodellen, de oppervlakte-massabalans, zal worden berekend met een regionaal atmosfeermodel op hoge resolutie. Dit model zal ook worden aangewend om de massabalans van de Groenlandse ijskap in een 2 x CO2 klimaat na te bootsen. In het kader van deze projecten zal Nederland ook deelnemen aan een nieuwe diepe boring in noord Groenland, die tot doel heeft het klimaat van de Noord-Atlantische regio mogelijk tot 140,000 jaar terug te reconstrueren.

Contact information

For more information, questions or comments please contact us using the email adres below.

Institute for Marine and Atmospheric research Utrecht Link
Email: imau @