Risk of sea ice and icebergs for field development in the Southwestern Barents Sea.

The Barents Sea is important for Norway in several ways, in particularly politically, environmentally and economically. The different economic activities (mostly Fisheries oil & gas and tourism) must be developed in a fruitful co-existence, and in a way that takes care of the fragile environment in times with climate change. RareIce deals with field development av oil and natural gas in the Southwestern Barents Sea. This is an area with rare presence of sea ice and icebergs, men we do not believe that the risk of sea ice and icebergs can be neglected. The content of RareIce is to document the low (but not zero) probabilities for sea ice and icebergs in the area and to quantify the effect this may have for the design and operation of facilities for the development of oil and gas resources. In these areas where one may only very rarely find sea ice or icebergs there is little data on ice extension and properties, and we cannot count on local measurements. The main idea is to combine measurements with simulations of physical processes. The ice that might be present in the Southwestern Barents Sea is not of local origin, it has drifted in from further north in the Barents Sea. We aim at measuring ice extension and properties further north I the Barents Sea where there is ice every year, apply physical laws, and simulate its drift and transformation on the way south. When it comes to icebergs we will identify which glaciers that may produce icebergs, how many icebergs these glaciers can produce and simulate their drift and melting down into the Southwestern Barents Sea. These models can be run with great many different meteorological and oceanic conditions and estimate the probability for ice with certain properties to drift into the area and finally asses the risk these may cause.

The Barents Sea is an important area for Norway in several ways, it is politically important for Norway to maintain governance of oceans around Svalbard, it is important breeding ground for Arctic cod and there is tourism and shipping. At the same time there are open areas for oil and gas exploration in the Southwest, and it is vital that all these activities can co-exists. For the oil and gas development the risk must be sufficiently low, that means that the probability of accidents is so small that it balances the consequences in the fragile Arctic nature. Occurrence of sea ice and icebergs in this area is rare, it can perhaps only drift down from the Northern Barents Sea every 100, or even 10.000 years. However, our starting point is that any field development needs to take ice into account. A safe and rational approach to assess the uncertainties with respect to these rare ice events must be developed and this is the prime concern of RareIce. The main idea is that since ice drifts down into the Southwestern Barents Sea so rarely its characteristics cannot be measured on site. RareIce proposes a three step procedure to assess the danger from ice to offshore structures in the Southwestern Barents Sea. Firstly, to characterize the ice conditions further North in the Barents Sea ("upstream") by a combination of remote sensing and modelling of physical processes. Secondly, let the ice drift south and model how the properties change as the ice drift south and into warmer waters. Thirdly, apply the transformed statistics of sea ice and icebergs and estimate the sea ice action on the proposed offshore structures. In RareIce we will combine measurements from above (remote sensing from satellites), in-situ fieldwork from scientific cruises and long-term measurements from under the ice (moored under water rigs deployed over many years) and derive ice statistic suitable for probabilistic design.