Modeling Climate and Deep Water Sensitivity to Changes in Deglacial Meltwater Flux and Location Using a Fully-Coupled Ocean-Atmosphere GCM

摘要ATM-9612684 deMenocal，Peter哥伦比亚大学题目：使用完全耦合的海洋-大气GCM模拟气候和深水对冰川融水通量和位置变化的敏感性 该奖项支持一个项目，该项目将使用同步耦合海洋-大气环流模型（O-A GCM）来研究快速，千年尺度气候变化事件的动力学起源，这些事件打断了末次冰期和冰消期。 重点将放在深循环和表面气候的反应，规定的变化，在供应和输入位置的冰川融水的海洋。 本提案中使用的NASA GISS O-A GCM是独一无二的，因为：1）它不需要通量校正来维持现实的大西洋深水循环，因此整个气候系统可以自由地调整以适应变化的边界条件，2）地表径流被组织在41个独立的河流流域中，允许点源淡水注入海洋，3）海洋模型是真正同步耦合（每小时）到一个完整的大气模型，和4）该模型支持氧同位素分馏和示踪剂代码，以监测格陵兰岛冰组成的变化。 将讨论三个研究重点：1）描述与控制模式中高和低深水生产相关的海洋-大气模式气候特征; 2）量化深环流对流入海洋的冰消融水流量和位置变化的敏感性; 3）新仙女木模拟：12，000 - 9，000年前不同的冰川消融径流量和输入位置的影响。

Abstract ATM-9612684 deMenocal, Peter Columbia University Title: Modeling Climate and Deep Water Sensitivity to Changes in Deglacial Meltwater Flux and Location Using a Fully-Coupled Ocean- Atmosphere GCM This award supports a project that will use a synchronously-coupled ocean-atmosphere general circulation model (O-A GCM ) to examine the dynamical origins of rapid, millennial-scale climate change events which punctuate the last glacial and deglacial periods. Focus will be on deep circulation and surface climate responses to prescribed changes in the supply and input location of deglacial meltwater to the ocean. The NASA GISS O-A GCM used in this proposal is unique because: 1) it does not require flux corrections to sustain realistic Atlantic deep water circulation so the entire climatic system is free to adjust to changed boundary conditions, 2) surface runoff is organized in 41 separate river drainages allowing for point-source freshwater injection to the ocean, 3) the ocean model is truly synchronously-coupled (every hour) to a full atmospheric model, and 4) the model supports oxygen-isotopic fractionation and tracer code to monitor resulting changes in Greenland ice composition. Three research foci will be addressed: 1) characterize the ocean-atmosphere model climate signatures associated with high and low deep-water production in the control model; 2) quantify deep circulation sensitivity to changes in the flux and location of deglacial meltwater input to the ocean; and 3) Younger Dryas simulation: effects of variable deglacial runoff volumes and input locations between 12,000-9,000 years ago.