High-resolution pre-industrial evolution of sea surface conditions in the Canadian Arctic

正如政府间气候变化专门委员会2007年的报告所指出的那样，人为排放温室气体导致的全球变暖现在已成为事实：“气候系统的变暖是明确的，从目前对全球平均空气和海洋温度上升、冰雪大范围融化和全球平均海平面上升的观察可以明显看出这一点。”最好的例子是2007年北极海冰的范围，这是有史以来最低的记录。北极生态系统和北部社区受这种变化的影响最大。因此，迫切需要为决策者制定现实和准确的气候情景，以便实施适应和缓解措施。我们的研究计划的主要目标是定量地重建过去300-400年（前工业时代/工业时代过渡）整个加拿大北极地区海面条件的演变，以便为气候建模者提供必要的边界条件，以测试下一代北极区域气候模型的准确性。以鞭毛藻包囊组合为替代指标，在多年时间分辨率下实现海面温度、盐度和海冰覆盖时间的定量重建。浮游生物（活动鞭毛藻组合）和地表沉积物样本（鞭毛藻囊组合）也将被分析和比较，以评估入侵水生物种和/或有害藻类爆发的威胁，这些威胁可能是由于水温升高和季节性海冰消失后西北航道航运流量增加造成的。这些结果将有助于决策者调整加拿大关于船舶压舱物处置和缓解的法规。

Global warming caused by the anthropogenic release of greenhouse gases is now a fact, as stated in the 2007 report of the Intergovernmental Panel on Climate change: "Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level". The best example is the extent of Arctic sea ice in 2007, which was the lowest ever recorded. The Arctic ecosystems and northern communities are the most affected by such changes. Therefore, there is a pressing need to develop realistic and accurate climate scenarios for decision makers to implement adaptation and mitigation measures. The main objective of our research program is to quantitatively reconstruct the evolution of sea surface conditions throughout the Canadian Arctic for the last 300-400 years (Pre-Industrial/ Industrial Era transition) in order to provide climate modelers with the necessary boundary conditions to test the accuracy of the next generation of regional climate models for the Arctic. The quantitative reconstruction of sea surface temperature, salinity and duration of sea ice cover will be realized at a pluri-annual time resolution using dinoflagellate cyst assemblages as proxy indicators. Plankton (motile dinoflagellate assemblages) and surface sediment samples (dinoflagellate cyst assemblages) will also be analyzed and compared to assess the threat of invasive aquatic species and/or harmful algal outbreak that may result from increasing water temperature and increased shipping traffic through the Northwest Passage following the disappearance of sea ice on a seasonal basis. These results will help decision makers to adapt the Canadian regulation on ship ballast disposal and mitigation.