Identification

Title

Contrasting the roles of regional anthropogenic aerosols from the western and eastern hemispheres in driving the 1980-2020 Pacific multi-decadal variations

Abstract

The multi-decadal variations in the Pacific climate are extensively discussed as being influenced by external forcings such as greenhouse gases (GHGs) and anthropogenic aerosols (AAs). Unlike GHGs, the potential impacts of AAs could be more complex because of the heterogeneity of spatial distribution during the past few decades. Here we show, using regional aerosol forcing large-ensemble simulations with the Community Earth System Model 1 (CESM1), that the increasing fossil-fuel-related aerosol emissions over Asia (EastFF) and the reduction in aerosol emissions over North America and Europe (WestFF) have remarkably different impacts on driving the Pacific circulations and sea surface temperature (SST) changes since the 1980s. EastFF excites a typical El Niño-like SST pattern in the tropical Pacific and weakens the climatological Pacific Walker circulation. WestFF induces a central Pacific (CP)-type El Niño-like SST pattern with warming in the middle region of the equatorial Pacific, which is consistent with the second leading empirical orthogonal function (EOF) pattern of the observation. Over the North Pacific region, EastFF, located at low to middle latitudes, favors an Interdecadal Pacific Oscillation (IPO)-like SST pattern (horseshoe-like SST pattern in the North Pacific) through a teleconnection pathway between the tropical and extratropical Pacific but is overwhelmed by internal variability evolving from a positive phase to a negative IPO phase. In contrast, WestFF, located at middle to high latitudes, strongly affects the North Pacific via a west-to-east mid-latitude pathway and induces extensive warming. The competing effects of the heterogeneously distributed regional aerosol forcings are expected to exhibit different patterns in the near future, especially the redistribution of aerosol emissions within the domain of EastFF (i.e., from East Asia to South Asia) and changes in aerosol composition. The complex future changes in anthropogenic aerosol emissions are likely to introduce more profound impacts of aerosol forcing on the Pacific multi-decadal variations.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7h70m6b

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

2025-02-19T00:00:00Z

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

<span style="font-family:Arial;font-size:10pt;font-style:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span>

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