Identification

Title

Seasonal and interannual variation of the interhemispheric coupling during the austral winter in WACCM6

Abstract

We investigate interhemispheric coupling (IHC) during the austral winter by examining global characteristics of the dynamical fields initiated by stratospheric warming in the Southern Hemisphere using output of the Whole Atmosphere Community Climate Model version 6 covering 195 simulation years. About 100 events were extracted and analyzed, focusing on the seasonal and interannual variation of the IHC response in the Northern Hemisphere. The seasonal variation can be explained by differences in the background atmosphere. The upward shift and weakening of the gravity wave forcing during the IHC in September are opposite to the characteristics of July and August. However, the mean zonal wind and the momentum deposition of gravity waves in the northern middle atmosphere in September are also opposite to those in July and August. Together, these result in the same sign of the anomaly. Additionally, an interannual variation in the altitude of the warming in the northern polar region is also observed, with warmings split at 100 km. A warming that appears above 100 km is explained by an additional mechanism of gravity wave modulation, which drives the winter‐to‐summer circulation in the lower thermosphere, while a warming below 100 km corresponds to the weakening of the summer‐to‐winter circulation in the upper mesosphere. Correspondingly, no warming is observed near 100 km, where the circulation and its modulation are absent. This interannual variation of the IHC is influenced by the intraseasonal oscillation, which represents a similar meridional temperature structure in the global middle atmosphere.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7794930

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2025-06-28T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact