Understanding and Constraining Future Arctic Climate Change

Hall 0714083 UCLAFunds被提供来理解和限制在当前一代气候模式中重要的北极海冰-冰反馈（SIAF）。为了减少模型中反馈模拟之间的传播，有必要确定可用于评估反馈真实性的观测约束。这里的核心困难在于，反馈是未来气候的各个方面，无法直接观察到。为了规避这一点，主要研究者（PI）的策略是量化模拟的SIAF强度，因为它影响了热带外地区外部强迫气候变率的最可观察和最突出的例子-当前气候的季节循环。如果模拟的SIAF强度在当前的季节性周期是一个很好的预测反馈强度在气候变化的背景下，那么观测约束反馈在当前的季节性周期应直接导致减少模型间传播的反馈强度在未来的气候预测。这似乎已经与PI的雪反馈的先前工作的情况下，和战略产生类似的结果，考虑到反馈的特点，SIAF已经概述。这项工作的一个重要对应部分将是确定当前气候模拟的哪些方面对SIAF强度及其模型间传播的影响最大。PI已经开发了一个数学框架，以方便从模型输出这些诊断。预计这项工作将侧重于海冰冰的参数化，但也将研究北极云在调节SIAF中的作用，以及海洋-海冰相互作用的作用。

Hall 0714083UCLAFunds are provided to understand and constrain the important arctic sea-ice-albedo feedback (SIAF) in the current generation of climate models. To reduce the spread between simulations of feedbacks in models, it is necessary to identify observational constraints that can be used to evaluate the feedback's realism. The central difficulty here is that the feedbacks are aspects of future climate, and cannot be observed directly. To circumvent this, the strategy of the principal investigator (PI) is to quantify simulated SIAF strength as it impacts the most observable and prominent example of externally-forced climate variability in the extratropics - the current climate's seasonal cycle. If simulated SIAF strength in the current seasonal cycle is an excellent predictor of feedback strength in the climate change context, then observational constraints on the feedback in the current seasonal cycle should lead directly to reductions in the intermodel spread of feedback strength in the future climate predictions. This appears to have been the case with the PI's previous work on snow albedo feedback, and a strategy for producing similar results for SIAF that takes into account the feedback's peculiarities has been outlined. An essential counterpart to this effort will be determining which aspects of current climate simulations influence SIAF strength and its intermodel spread the most. The PI has developed a mathematical framework to facilitate these diagnoses from model output. It is anticipated that the work will focus on sea ice albedo parameterizations, but will also examine the role of arctic clouds in modulating SIAF, as well as the role of ocean-sea-ice interaction.