持续的正北大西洋涛动模式主导了中世纪气候异常。

Persistent positive North Atlantic oscillation mode dominated the Medieval Climate Anomaly.

作者信息

Trouet Valérie, Esper Jan, Graham Nicholas E, Baker Andy, Scourse James D, Frank David C

机构信息

Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland.

出版信息

Science. 2009 Apr 3;324(5923):78-80. doi: 10.1126/science.1166349.

DOI:10.1126/science.1166349

PMID:19342585

Abstract

The Medieval Climate Anomaly (MCA) was the most recent pre-industrial era warm interval of European climate, yet its driving mechanisms remain uncertain. We present here a 947-year-long multidecadal North Atlantic Oscillation (NAO) reconstruction and find a persistent positive NAO during the MCA. Supplementary reconstructions based on climate model results and proxy data indicate a clear shift to weaker NAO conditions into the Little Ice Age (LIA). Globally distributed proxy data suggest that this NAO shift is one aspect of a global MCA-LIA climate transition that probably was coupled to prevailing La Niña-like conditions amplified by an intensified Atlantic meridional overturning circulation during the MCA.

摘要

中世纪气候异常（MCA）是欧洲气候在工业化前时代最近的一个暖期，但它的驱动机制仍不确定。我们在此展示了一个长达947年的北大西洋涛动（NAO）多年代际重建，并发现MCA期间NAO持续为正。基于气候模型结果和代用数据的补充重建表明，进入小冰期（LIA）时NAO状况明显转向较弱。全球分布的代用数据表明，这种NAO转变是全球MCA - LIA气候转变的一个方面，这一转变可能与MCA期间因大西洋经向翻转环流增强而放大的盛行的类似拉尼娜的状况有关。