Anticyclonic suppression of the North Pacific transient eddy activity in midwinter

Author:

Nakamura Hisashi1,Kaspi Yohai2,Okajima Satoru3ORCID

Affiliation:

1. University of Tokyo

2. Department of Earth and Planetary Sciences, Weizmann Institute of Science

3. Research Center for Advanced Science and Technology, The University of Tokyo

Abstract

Abstract Dynamical understandings of midlatitude transient eddy activity, especially its midwinter minimum over the North Pacific, are still limited, partly because Eulerian eddy statistics are incapable of separating cyclonic and anticyclonic contributions. Here we evaluate the two contributions separately based on local curvature of instantaneous flow fields to compare their seasonality between the North Pacific and North Atlantic storm-tracks. The anticyclonic contribution is found crucial for the midwinter minimum of the North Pacific transient eddy activity. Eddy energetics reveals that the net efficiency of the anticyclonic contribution in replenishing total transient eddy energy over the North Pacific exhibits a pronounced midwinter minimum, while that of the cyclonic counterpart maximizes around midwinter in harmony with precipitation. The anticyclonic contribution is also pivotal to interannual and decadal-scale variability of wintertime transient eddy activity that is anti-correlated with the westerly jet speed, especially over the North Pacific. This study suggests that more attention should be paid to anticyclones in studying midlatitude storm-track dynamics.

Publisher

Research Square Platform LLC

Reference59 articles.

1. Quantifying the relevance of cyclones for precipitation extremes;Pfahl S;J. Clim.,2012

2. Serial clustering of extratropical cyclones: a review of where, when and why it occurs;Dacre HF;npj Climate and Atmospheric Science,2020

3. Transient Eddy forcing of the rotational flow during Northern winter;Hurrell JW;J. Atmos. Sci.,1995

4. Power spectrum analysis of climatological data for Woodstock College, Maryland;Landsberg HE;Mon. Weather Rev.,1959

5. Power spectrum of horizontal wind speed in the frequency range from 0.0007 to 900 cycles per hour;Hoven I;J. Atmos. Sci.,1957

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3