Identification

Title

Tidal impact on quiet‐time polar thermosphere zonal winds during northern winter sudden stratospheric warmings

Abstract

This study primarily examines the variability of zonal winds in the geomagnetic “quiet‐time” (AE index < 190 nT; Kp index < 2) thermosphere over Alaska (60–75°N) during the winter months from November 2018 to February 2019, and demonstrates a correlation of the meteor radar observed zonal winds at heights 82–98 km with Scanning Doppler Imager observed zonal wind variability at heights 120 and 250 km during nighttime. Notably, over Alaska following a mid‐winter sudden stratosphere warming (SSW) event, the zonal wind magnitudes on tidal timescale (difference between maximum eastward and minimum westward wind values over a 6‐hr interval during nighttime) in the thermosphere experience about two‐fold increase at observed thermosphere altitudes (98, 120, and 250 km). Additional validation of observational findings comes from SD‐WACCM‐X model simulations across solar‐minimum (2017–2021) winters, including both non‐SSW and SSW events (occurring in different winters). The model indicates that the SSW‐induced response in zonal wind tidal magnitudes may be indistinguishable from the seasonal trend in late winter, while it is more pronounced when the seasonal variations is minimal during mid‐winter months. By tidal diagnostics of zonal winds from meteor radar observations and SD‐WACCM‐X simulations at polar latitudes, a connection is established between the thermosphere zonal wind variations and the semidiurnal originating in the lower atmosphere following the SSW onset within the altitude range of 90–300 km (i.e., ionosphere‐thermosphere region). Additionally, the study highlights the migrating solar semidiurnal tides as a major contributor in the variability in the polar thermosphere region with minor contribution from lunar semidiurnal tides.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7zc879k

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

2025-02-01T00:00:00Z

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