1 Descriptive Section

1.1 Indicator category

Habitat-Physical

1.2 Indicator name

Arctic Oscillation Index

Includes variable(s): ALL

1.3 Indicator brief description

The Arctic Oscillation Index (AO) describes changing patterns over time of atmospheric pressure around the North Pole that affect the location of the mid-latitude Jet Stream. The indicator focuses on annual changes in winter AO by averaging monthly NAO indices for January, February, and March each year.

1.4 Indicator visualization

The winter AO has oscillated since 1950 between negative (higher Arctic pressure and weak winds allow Arctic air deeper into mid-latitudes) and positive (lower Arctic pressure and strong winds keep Arctic air in the Arctic) phases at 20-30 year intervals. It has been neutral or positive since 2014 and trended toward neutral in 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
Arctic Oscillation Index

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

General overview: Annual and Monthly

Indicator specifics:

Indicator	EPU	StartYear	EndYear
Arctic Oscillation Index	Northern Hemisphere	1950	2025

2.1.2.3 Spatial location, scale and extent

General overview: AO PCA

Indicator specifics:

Indicator	EPU
Arctic Oscillation Index	Northern Hemisphere

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

Global scale applying to the entire Northern Hemisphere; 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

2.1.4.2 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?

Annually for the winter index, daily for daily AO indices.

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

2.2.2 What implications of the indicators are currently listed?

The positive phase of the AO generally means a more northerly jet stream that results in fewer cold weather conditions in the Mid-Atlantic. The negative phase can push the jet stream further south, bringing Arctic air into the northeast US and resulting in more Nor’easters. See https://www.climate.gov/news-features/understanding-climate/climate-variability-arctic-oscillation

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, the NOAA National Weather Service Climate Prediction Center routinely compares observed daily AO indices with forecast AO indices. See https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index_ensm.shtml

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	Arctic Oscillation Index	Specific	Described	1	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Specific	Units	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Specific	Spatial	1	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Specific	Uncertainty	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Specific	Methods	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Specific	Code	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Measurable	Available	1	0.8333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Measurable	Online	1	0.8333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Measurable	Contact	1	0.8333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Measurable	SourceDat	1	0.8333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Measurable	SourceAvail	1	0.8333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Measurable	SourceContact	0	0.8333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Achievable	Tested	1	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Achievable	Sensitivity	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Achievable	TimeLag	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Relevant	Advice	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Relevant	Implications	1	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Relevant	TargThresh	0	0.3333333	0.5666667
Habitat-Physical	Arctic Oscillation Index	Timebound	Frequency	1	1.0000000	0.5666667
Habitat-Physical	Arctic Oscillation Index	Timebound	Updated	1	1.0000000	0.5666667

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]

SMART Indicator Report: Arctic Oscillation Index

SMART Indicator Report: Arctic Oscillation Index

1 Descriptive Section

1.1 Indicator category

1.2 Indicator name

1.3 Indicator brief description

1.4 Indicator visualization

2 SMART Attribute Section

2.1 Indicator documentation

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

2.1.1.1 Where can indicators be found?

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

2.1.1.3 Who is the contact?

2.1.2 Gather indicator statistics

2.1.2.1 Units

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

2.1.2.3 Spatial location, scale and extent

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

2.1.2.5 Uncertainty metrics

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

2.1.3.1 Can the indicator be calculated from current documentation?

2.1.3.2 Is code publicly available? up to date?

2.1.3.3 Have methods changed over time?

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

2.1.4.1 Where are source data stored?

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

2.1.4.3 How often are they updated?

2.2 Indicator analysis/testing or history of use

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

2.2.2 What implications of the indicators are currently listed?

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

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

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

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

3 SMART rating

3.1 Comments

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

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

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