Tracing Shifts: Interdecadal Variations of NAO and PNA Patterns from the Nineteenth Century across Multiple Reanalyses

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F25%3A00618415" target="_blank" >RIV/68378289:_____/25:00618415 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11310/25:10503852

Result on the web

<a href="https://journals.ametsoc.org/view/journals/clim/38/6/JCLI-D-24-0037.1.xml" target="_blank" >https://journals.ametsoc.org/view/journals/clim/38/6/JCLI-D-24-0037.1.xml</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1175/JCLI-D-24-0037.1" target="_blank" >10.1175/JCLI-D-24-0037.1</a>

Result language

angličtina

Original language name

Tracing Shifts: Interdecadal Variations of NAO and PNA Patterns from the Nineteenth Century across Multiple Reanalyses

Original language description

This study examines the spatial structures of the North Atlantic Oscillation (NAO) and Pacific-North American (PNA) pattern across five reanalyses and investigates their temporal changes. Using winter monthly mean anomalies of 500-hPa geopotential heights from ensemble mean fields and individual ensemble members, we apply a moving principal component analysis (PCA) to 40-yr periods. Our findings reveal that the modes can vary significantly even with slight changes in the analyzed period. We observe that the lack of constraint over the North Pacific leads to different PNA patterns in individual ensemble members, resulting in a smoothed and weaker PNA in the ensemble mean. Therefore, we recommend using ensemble members instead of the ensemble mean before 1900 when analyzing low-frequency variability in 20CRv2 or 20CRv3. Despite differences in data assimilation, period length, and models among reanalyses, trends in explained variance and spatial changes of both PNA and NAO are similar. We also identified a decrease in the similarity of the NAO pattern around 1962-2001 across all datasets, linked to a sudden southward shift in the mode, indicating a change in variability in the reanalyses, independent of the data source or the model. The temporal changes, including long-term trends, likely have a fundamental basis, although sudden changes from period to period are rather artifacts from the PCA.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10509 - Meteorology and atmospheric sciences

Project

<a href="/en/project/GA17-07043S" target="_blank" >GA17-07043S: Teleconnections - major building blocks of atmospheric circulation</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Climate

ISSN

0894-8755

e-ISSN

1520-0442

Volume of the periodical

38

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

1521-1533

UT code for WoS article

001443757600001

EID of the result in the Scopus database

2-s2.0-86000721264