SMART Indicator Report: Pacific Decadal Oscillation

1 Descriptive Section

1.1 Indicator category

Habitat-Physical

1.2 Indicator name

Pacific Decadal Oscillation

Includes variable(s): ALL

1.3 Indicator brief description

The Pacific Decadal Oscillation (PDO) measures differences over time in the patterns of sea surface temperature in the North Pacific.

1.4 Indicator visualization

The PDO has varied over time since the 1850s between positive (warmer in the eastern Pacific) and negative (warmer in the Western Pacific) phases and is currently in a negative phase.

2 SMART Attribute Section

2.1 Indicator documentation

2.1.1 Are indicators available for others to use (data downloadable)?

Yes

2.1.1.1 Where can indicators be found?

All marea indicators are here: https://github.com/MarEcosystemApproaches/marea

2.1.1.2 How often are they updated? Are future updates likely?

Unknown

2.1.1.3 Who is the contact?

Jamie C. Tam jamie.tam@dfo-mpo.gc.ca

2.1.2 Gather indicator statistics

2.1.2.1 Units

Indicator	Units
Pacific Decadal Oscillation

2.1.2.2 Length of time series, start and end date, periodicity

General overview: Annual and Monthly

Indicator specifics:

Indicator	EPU	StartYear	EndYear
Pacific Decadal Oscillation	North Pacific	1854	2025

2.1.2.3 Spatial location, scale and extent

General overview: PDO index area

Indicator specifics:

Indicator	EPU
Pacific Decadal Oscillation	North Pacific

2.1.2.4 Management scale: all species, FMP level, species level, can it be aggregated or separated to different scales?

Basinwide scale applying to the entire North Pacific; cannot be aggregated or separated.

2.1.2.5 Uncertainty metrics

Uncertainty is captured in these variables:

character(0)

2.1.3 Are methods clearly documented to obtain source data and calculate indicators?

No methods documentation is provided

2.1.3.1 Can the indicator be calculated from current documentation?

No. No methods documentation is provided

2.1.3.2 Is code publicly available? up to date?

No. No link to code in metadata

2.1.3.3 Have methods changed over time?

Unknown

2.1.4 Are indicator underlying source data linked or easy to find?

Yes. Source information included: NOAA ERSST, https://www.ncei.noaa.gov/access/monitoring/pdo/

2.1.4.1 Where are source data stored?

Source data stored at NOAA ERSST, https://www.ncei.noaa.gov/access/monitoring/pdo/

2.1.4.2 How/by whom are source data updated? Are future updates likely?

No. No source data steward information

2.1.4.3 How often are they updated?

Monthly? https://www.ncei.noaa.gov/products/extended-reconstructed-sst

2.2 Indicator analysis/testing or history of use

2.2.1 What decision or advice processes are the indicators currently used in?

None known in the Mid-Atlantic. The PDO regime shift of 1977 is used as the basis for defining some assessment time series in the North Pacific.

2.2.2 What implications of the indicators are currently listed?

Shifts in the PDO were originally tied to changes in Pacific salmon production, in addition to changes in coastal weather from Alaska and California. See https://journals.ametsoc.org/view/journals/bams/78/6/1520-0477_1997_078_1069_apicow_2_0_co_2.xml . However, ecological relationships with the PDO have weakened recently because the whole North Pacific has warmed to the extent that the negative PDO phase no longer has “cool” temperatures biologically. See https://www.nature.com/articles/s41558-025-02482-z

2.2.3 Do target, limit, or threshold values already exist for the indicator?

No.

2.2.4 Have the indicators been tested to ensure they respond proportionally to a change in the underlying process?

Yes, there are indications that ecosystem response is no longer proportional to the PDO phase; see https://www.nature.com/articles/s41558-025-02482-z

2.2.5 Are the indicators sensitive to a small change in the process, or what is the threshold of change that is detectable?

Unknown

2.2.6 Is there a time lag between the process change and the indicator change? How long?

Unknown

3 SMART rating

Category	Indicator	Element	Attribute	Rating	ElementRating	OverallRating
Habitat-Physical	Pacific Decadal Oscillation	Specific	Described	1	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Specific	Units	0	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Specific	Spatial	1	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Specific	Uncertainty	0	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Specific	Methods	0	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Specific	Code	0	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Measurable	Available	1	0.8333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Measurable	Online	1	0.8333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Measurable	Contact	1	0.8333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Measurable	SourceDat	1	0.8333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Measurable	SourceAvail	1	0.8333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Measurable	SourceContact	0	0.8333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Achievable	Tested	1	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Achievable	Sensitivity	0	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Achievable	TimeLag	0	0.3333333	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Relevant	Advice	1	0.6666667	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Relevant	Implications	1	0.6666667	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Relevant	TargThresh	0	0.6666667	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Timebound	Frequency	1	1.0000000	0.6333333
Habitat-Physical	Pacific Decadal Oscillation	Timebound	Updated	1	1.0000000	0.6333333

3.1 Comments

3.1.1 Additional potential links to management in addition to uses listed above

[Select from list of management processes/actions using exact keywords]

3.1.2 What additional work would be needed for the Council to use the indicator?

[List current gaps in the indicator given the current or potentail uses listed above, what resources are needed?]

3.1.3 What issues are caused if there is a gap or delay in data underlying the indicator

[Link to management process/actions and their requirements]