Climate sensitivity and meridional overturning circulation in the late Eocene using GFDL CM2.1
Climate sensitivity and meridional overturning circulation in the late Eocene using GFDL CM2.1
复制标题
使用 GFDL CM2.1 始新世晚期的气候敏感性和经向翻转环流
作者：
D. Hutchinson;A. D. de Boer;H. Coxall;R. Caballero;J. Nilsson;M. Baatsen
抽象的。始新世-渐新世过渡（EOT）发生在大约34 Ma前，是一个
这段时间对地球气候历史非常感兴趣，因为
南极冰盖和全球变冷的影响。气候
需要过渡的模拟来帮助解释代理数据，
测试过渡的机制假设，并确定气候
当时的敏感度。然而，到目前为止，EOT的模型研究通常
采用为不同时期或海洋设计的控制状态
决议案的顺序为3次。在这里，我们开发了一种新的更高的
基于GFDLCM2.1气候的高分辨率古气候模式配置
模型适用于晚始新世（38马）古地理重建。的
海洋和大气的水平分辨率为1 × 1.5 × 1.5
和3 μ m × 3.75 μ m。这表示
在解决海洋地理、门户和
在这一时期的气候模式耦合环流。我们运行这个模型，
三种不同的大气二氧化碳水平：400，800和1600 ppm。模型
与其他最近的研究相比，
模型研究，从而可以捕捉到预期的始新世高纬度温暖
在观测到的大气CO2浓度范围内。然而，该模型
无法捕捉到代理表中的低纬向温度梯度。
模型中赤道海面温度过高
（30-37 ℃）与观测值（最高32 ℃）相比，尽管
在西太平洋最温暖的地区缺乏观测。的
模型显示了北太平洋和南大洋的两极下沉，
在所有二氧化碳水平下都持续存在。北大西洋表面盐度
太新鲜，不允许下沉（25-30 psu），由于表面运输，
非常新鲜的北极（2000 psu），
近似同意始新世代理估计。北大西洋盐度
当CO2减半时增加1-2 psu，当
由于水文循环的变化，二氧化碳增加了一倍。
Abstract. The Eocene–Oligocene transition (EOT), which took place approximately 34 Ma ago, is an
interval of great interest in Earth's climate history, due to the inception
of the Antarctic ice sheet and major global cooling. Climate
simulations of the transition are needed to help interpret proxy data,
test mechanistic hypotheses for the transition and determine the climate
sensitivity at the time. However, model studies of the EOT thus far typically
employ control states designed for a different time period, or ocean
resolution on the order of 3∘. Here we developed a new higher
resolution palaeoclimate model configuration based on the GFDL CM2.1 climate
model adapted to a late Eocene (38 Ma) palaeogeography reconstruction. The
ocean and atmosphere horizontal resolutions are 1∘ × 1.5∘
and 3∘ × 3.75∘ respectively. This represents a
significant step forward in resolving the ocean geography, gateways and
circulation in a coupled climate model of this period. We run the model under
three different levels of atmospheric CO2: 400, 800 and 1600 ppm. The model
exhibits relatively high sensitivity to CO2 compared with other recent
model studies, and thus can capture the expected Eocene high latitude warmth
within observed estimates of atmospheric CO2. However, the model does
not capture the low meridional temperature gradient seen in proxies.
Equatorial sea surface temperatures are too high in the model
(30–37 ∘C) compared with observations (max 32 ∘C), although
observations are lacking in the warmest regions of the western Pacific. The
model exhibits bipolar sinking in the North Pacific and Southern Ocean, which
persists under all levels of CO2. North Atlantic surface salinities are
too fresh to permit sinking (25–30 psu), due to surface transport from the
very fresh Arctic (∼ 20 psu), where surface salinities
approximately agree with Eocene proxy estimates. North Atlantic salinity
increases by 1–2 psu when CO2 is halved, and similarly freshens when
CO2 is doubled, due to changes in the hydrological cycle.
影响因子：
--
作者：
Inglis, Gordon N.;Farnsworth, Alexander;Pancost, Richard D.
通讯作者：
Pancost, Richard D.
DOI：
10.1073/pnas.1714744115
发表时间：
2018-02-06
影响因子：
11.1
作者：
Evans, David;Sagoo, Navjit;Affek, Hagit P.
通讯作者：
Affek, Hagit P.
影响因子：
4.3
作者：
Lunt, Daniel J.;Farnsworth, Alex;Wrobel, Neil
通讯作者：
Wrobel, Neil