SMART Indicator Report: North Pacific Gyre Oscillation

1 Descriptive Section

1.1 Indicator category

Habitat-Physical

1.2 Indicator name

North Pacific Gyre Oscillation

Includes variable(s): ALL

1.3 Indicator brief description

The North Pacific Gyre Oscillation (NPGO) characterizes changes in sea surface temperature and height over time in the North Pacific which are linked to ocean circulation changes that affect the distribution of salinity and nutrients in the California Current and Gulf of Alaska.

1.4 Indicator visualization

The NPGO has oscillated since 1950 between positive (stronger coastal current transport, stronger upwelling in California and downwelling in Alaska) and negative (opposite conditions) phases approximately decadally. It has remained in a negative phase for the past decade (2016-2025).

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
North Pacific Gyre Oscillation	normalized anomaly

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

General overview: Annual and Monthly

Indicator specifics:

Indicator	EPU	StartYear	EndYear
North Pacific Gyre Oscillation	North Pacific Gyre	1950	2025

2.1.2.3 Spatial location, scale and extent

General overview: NPGO

Indicator specifics:

Indicator	EPU
North Pacific Gyre Oscillation	North Pacific Gyre

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?

Yes. The original study (https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2007GL032838) used one set of input data for sea surface height, which has been replaced with a newer data source in the NPGO calculations past 2004.

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

Yes. Source information included: Di Lorenzo et al., http://www.o3d.org/npgo/

2.1.4.1 Where are source data stored?

Source data stored at Di Lorenzo et al., http://www.o3d.org/npgo/

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.o3d.org/npgo/data/NPGO.txt

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.

2.2.2 What implications of the indicators are currently listed?

The NPGO links ocean conditions to primary productivity and therefore may help predict ecosystem productivity in the North Pacific. This indicator series is reproduced by Copernicus who note that the current negative phase corresponds to lower coastal upwelling, lower salinity at the surface, and lower nutrient concentrations, presumably in the California Current. See https://data.marine.copernicus.eu/product/OMI_EXTREME_CLIMVAR_PACIFIC_npgo_sla_eof_mode_projection/description?view=-&option=-&task=results&product_id=-

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?

Some testing using comparative modeling has been completed to determine whether the pattern is linked to the atmospheric driver. See https://journals.ametsoc.org/view/journals/clim/31/6/jcli-d-17-0344.1.xml

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	North Pacific Gyre Oscillation	Specific	Described	1	0.5000000	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Specific	Units	1	0.5000000	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Specific	Spatial	1	0.5000000	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Specific	Uncertainty	0	0.5000000	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Specific	Methods	0	0.5000000	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Specific	Code	0	0.5000000	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Measurable	Available	1	0.8333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Measurable	Online	1	0.8333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Measurable	Contact	1	0.8333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Measurable	SourceDat	1	0.8333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Measurable	SourceAvail	1	0.8333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Measurable	SourceContact	0	0.8333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Achievable	Tested	1	0.3333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Achievable	Sensitivity	0	0.3333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Achievable	TimeLag	0	0.3333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Relevant	Advice	0	0.3333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Relevant	Implications	1	0.3333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Relevant	TargThresh	0	0.3333333	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Timebound	Frequency	1	1.0000000	0.6
Habitat-Physical	North Pacific Gyre Oscillation	Timebound	Updated	1	1.0000000	0.6

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]