Interannual Relationship between the Boreal Spring Arctic Oscillation and the Northern Hemisphere Hadley Circulation Extent

This study investigates the interannual relationship and the dynamical linkage between the boreal spring Arctic Oscillation (AO) and the Northern Hemisphere Hadley circulation extent (HCE). The spring AO is positively correlated with the HCE, with one standard positive deviation of the AO index corr...

Full description

Saved in:
Bibliographic Details
Published in:Journal of climate 2019-07, Vol.32 (14), p.4395-4408
Main Authors: Hu, Dingzhu, Guo, Yi-Peng, Tan, Zhe-Min, Guan, Zhaoyong
Format: Article
Language:English
Subjects:
Arctic Oscillation
Atmospheric forcing
Atmospheric pressure
Datasets
Eddy momentum flux
Fluctuations
Flux
Hadley circulation
Latitude
Momentum
Momentum flux
Momentum transfer
North Atlantic Oscillation
Northern Hemisphere
Ocean-atmosphere system
Planetary wave propagation
Planetary waves
Precipitation
Propagation
Refractive index
Refractivity
Spring
Spring (season)
Studies
Summer
Vortices
Wave propagation
Winds
Zonal winds
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study investigates the interannual relationship and the dynamical linkage between the boreal spring Arctic Oscillation (AO) and the Northern Hemisphere Hadley circulation extent (HCE). The spring AO is positively correlated with the HCE, with one standard positive deviation of the AO index corresponding to approximately 0.42° latitude poleward shift of the HCE. The interaction between the planetary wave and the zonal winds over the subtropics results in an anomalous eddy momentum flux divergence, which shifts the HCE poleward. The AO related transient eddy momentum flux divergence makes nearly 2 times larger contributions than those of the stationary component to the HCE change. The increased equatorward transient wave flux over the subtropics is possibly related to the larger meridional gradient of the transient wave refractive index there. The AO positive phase corresponds to an enhanced planetary wave propagation from the midlatitude Atlantic Ocean to the subtropics, which resembles the North Atlantic Oscillation pattern. The autumn and winter AO–HCE relationship is similar to that during spring, while summer has the weakest relationship, which could be mainly attributed to the far poleward extension of the climatological HCE during summer.
ISSN:0894-8755
1520-0442
DOI:10.1175/JCLI-D-18-0657.1