Towards a better understanding of polar climate variability

点击翻译按钮获取中文摘要

Polar regions are a key component of the Earth's climate system, and are changing dramatically under anthropogenic climate change. The single greatest challenge for polar climate science is that there are not enough data to describe the climatology and trends. As a result, even though Greenland and Antarctica are perhaps the most sensitive regions on Earth to climate change, it is still very difficult to precisely answer questions like "How much have they been warming over the past 50 years?", and even more difficult to put recent observations in the context of natural climate variability. The overarching goal of this research program is to better understand polar climate changes in the past, present and future, with an emphasis on temperature, and the hydrological cycle (precipitation, atmospheric humidity). To this aim, we will provide records in key locations using paleoclimate data, investigate processes with in-situ measurements and controlled laboratory experiments, bring many datasets together to get the bigger picture, and provide benchmarks to evaluate climate models in polar regions. In this 5-year program, we will focus on 3 objectives: -Quantify the interannual variability of Antarctic surface winds, its response to climate change, and its impact on the water cycle, using a polar oriented regional climate model, and new observations on the steep slopes of the Antarctic plateau. -Use databases of Antarctic paleoclimate records to better describe Antarctic climate variability at decadal and longer timescales during the late Holocene by reconstructing modes of variability (such as the Southern Annular Mode), rather than climate variables like temperature or snow accumulation. -Investigate the mechanisms driving modern changes in Arctic humidity, using new measurements of water vapour isotopic composition in the Western Canadian Arctic, and on the Müller ice cap (80°N,91°W). This humidity increase is a key component in the feedback mechanisms responsible for Arctic amplification. In the short term, this program will produce key new datasets that will improve our fundamental understanding on the response of polar regions to climate change. We will produce readily useable benchmarks to evaluate climate models, which will lead in the medium term to an improvement of the quality of climate projections in polar regions, and elsewhere. This research will benefit Canada by providing new observations and understanding of a large, under-studied, region in the Western Canadian Arctic. More generally, the improvement of our knowledge of polar climate change will improve the accuracy of future climate projections, and adaptation plans that depend on them. This program will train HQP with a broad range of skills in isotope geochemistry, data analysis and climate modelling. The emphasis of early-career HQP is intended to improve diversity in Earth Science by attracting future research scientists early in their academic careers.