The role of ocean dynamics in producing decadal climate variability in the North Pacific

AbstractDecadal climate prediction can provide invaluable information for decisions made by government agencies and industry. Modes of internal variability of the ocean play an important role in determining the climate on decadal time scales. This study explores the possibility of using self-organizing maps (SOMs) to identify decadal climate variability, measure theoretical decadal predictability, and conduct decadal predictions of internal climate variability within a long control simulation. SOM is applied to an 11-yr running-mean winter sea surface temperature (SST) in the North Pacific and North Atlantic Oceans within the Community Earth System Model 1850 preindustrial simulation to identify patterns of internal variability in SSTs. Transition probability tables are calculated to identify preferred paths through the SOM with time. Results show both persistence and preferred evolutions of SST depending on the initial SST pattern. This method also provides a measure of the predictability of these SST patterns, with the North Atlantic being predictable at longer lead times than the North Pacific. In addition, decadal SST predictions using persistence, a first-order Markov chain, and lagged transition probabilities are conducted. The lagged transition probability predictions have a reemergence of prediction skill around lag 15 for both domains. Although the prediction skill is very low, it does imply that the SOM has the ability to predict some aspects of the internal variability of the system beyond 10 years.

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3D Structure of Striations in the North Pacific

Journal of Physical Oceanography ◽

10.1175/jpo-d-21-0076.1 ◽

2021 ◽

Author(s):

YU ZHANG ◽

YU PING GUAN ◽

RUI XIN HUANG

Keyword(s):

North Pacific ◽

3D Structure ◽

Three Dimensional ◽

Vertical Plane ◽

Dimensional Structure ◽

The North ◽

Layer Analysis ◽

Fluid Potential ◽

The North Pacific

AbstractOcean striations are composed of alternating quasi-zonal band-like flows; this kind of organized structure of currents be found in all world’s oceans and seas. Previous studies have mainly been focused on the mechanisms of their generation and propagation. This study uses the spatial high-pass filtering to obtain the three-dimensional structure of ocean striations in the North Pacific in both the z-coordinate and σ-coordinate based on 10-yr averaged SODA3 data. First, we identify an ideal-fluid potential density domain where the striations are undisturbed by the surface forcing and boundary effects. Second, using the isopycnal layer analysis, we show that on isopycnal surfaces the orientations of striations nearly follow the potential vorticity (PV) contours, while in the meridional-vertical plane the central positions of striations are generally aligned with the latitude of zero gradient of the relative PV. Our analysis provides a simple dynamical interpretation and better understanding for the role of ocean striations.

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Looking for the Role of the Ocean in Tropical Atlantic Decadal Climate Variability*

Journal of Climate ◽

10.1175/1520-0442(2001)014<0638:lftrot>2.0.co;2 ◽

2001 ◽

Vol 14 (5) ◽

pp. 638-655 ◽

Cited By ~ 37

Author(s):

Richard Seager ◽

Yochanan Kushnir ◽

Ping Chang ◽

Naomi Naik ◽

Jennifer Miller ◽

...

Keyword(s):

Climate Variability ◽

Tropical Atlantic ◽

Decadal Climate Variability ◽

Decadal Climate

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