Arctic-Tropical Teleconnections in the climate system (ArcTrop)

气候系统中的北极-热带遥相关 (ArcTrop)

• 批准号: 577112-2022
• 负责人: Pausata, FrancescoSalvatoreRoccoFSR
• 金额: $ 3.28万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765308
• 关键词: Arctic; Tropical; Teleconnections; climate; system

Ongoing climate change is accompanied by rapid, partly chaotic, variations in atmospheric, ocean, cyrospheric and land surface conditions that affect not only air temperature, but also the hydrological cycle, sea ice and ice sheets, sea level, ocean circulation including coastal currents. While observation techniques allow high resolution spatial and temporal monitoring of the climate system under anthropogenic forcing, the "pre-anthropogenic" state and natural variability of the system offer the opportunity to explore the behavior of the climate system under extreme conditions, warmer or colder than present, and during important transitions such as the one that led to the desertification of the Sahara, which was covered by a diverse vegetation until about 6,000-5,000 years ago. Here we aim at investigating potential mutual feedbacks between Arctic and tropical climate. We will use a combination of climate and forced ocean model simulations of different complexity and paleoclimate archives to delve into the rapid ice melting phase of the last deglaciation that led to > 120 m global sea-level rise and the current interglacial period that started about 11,700 years ago. The time interval of interest has been punctuated by abrupt climate change at regional as well as hemispheric scale both in the Arctic and in the tropical regions, like for example the Younger Dryas (12,900 - 11,700 years ago) that was accompanied by cooling close to 8°C in western Europe and the inception and withdrawal of the steppe-forest vegetation in the Sahara during the African Humid Period (14,500 - 5,000 years ago). These events occurred at a pace much faster than the underlining external forcing (changes in solar insolation) not only highlighting the presence of critical tipping points in the climate system but also suggesting potential feedbacks between high and low latitudes. Hence, in this context, by combining modeling and paleoclimate data, the overall goal of this project is to unravel key far-field connections between the Arctic and tropical latitude as they could play a key role in amplifying climate change and ice melt at high latitudes, and in altering monsoonal precipitation and droughts at low latitudes.

持续的气候变化伴随着大气、海洋、冰冻圈和陆地表面条件的快速、部分混乱的变化，这些变化不仅影响气温，而且影响水文循环、海冰和冰盖、海平面、包括沿海洋流在内的海洋环流。虽然观测技术允许对人为强迫下的气候系统进行高分辨率的时空监测，但系统的“人类活动前”状态和自然变异性提供了一个机会，可以探索气候系统在极端条件下的行为，比现在更热或更冷，以及在导致撒哈拉沙漠化的重要过渡期间，直到大约6000 - 5000年前，这里还被各种各样的植被覆盖着。在这里，我们的目标是调查北极和热带气候之间的潜在相互反馈。我们将结合不同复杂性的气候和强迫海洋模型模拟和古气候档案，深入研究导致全球海平面上升> 120米的最后一次冰消期的快速冰融化阶段和大约11，700年前开始的当前间冰期。在北极和热带地区，如新仙女木，区域和半球尺度的气候突变打断了感兴趣的时间间隔（12,900 - 11，700年前），伴随着西欧接近8°C的降温，以及非洲潮湿时期撒哈拉草原森林植被的开始和消失（14,500 - 5,000年前）。这些事件发生的速度远远快于所强调的外部强迫（太阳日射量的变化），不仅突出了气候系统中关键临界点的存在，而且还表明了高纬度和低纬度之间的潜在反馈。因此，在这种情况下，通过结合建模和古气候数据，该项目的总体目标是揭示北极和热带纬度之间的关键远场联系，因为它们可以在放大高纬度的气候变化和冰融化以及改变低纬度的季风降水和干旱方面发挥关键作用。