Predictions Working Group - Aspects

1. What do we want to predict?

- Ice extent, thickness/morphology, age distribution, stability and hazards from perspectives of key ice user groups.

- Regions of Interest: Northern sea route, Northwest Passage, Pacific Sector (Bering, Chukchi, Beaufort Seas)

- Probability of event.

2. What do we need for predictions?

- State of the ice: ice extent, ice thickness/morphology, ice age.

- State of the atmosphere: Seasonal forecasts (NCEP/ECMWF), atmospheric patterns or modes of variability, clouds.

- State of the ocean: SST, heat content, heat transport, halocline, mixed-layer depth.

- Observations, models, experience from historical perspective.

Predictions Working Group - General Questions (Relate to Understanding)

What are the roles of atmosphere-ocean-ice forcing or preconditioning?

Do we know something about the response of the ice to changes in atmospheric and oceanic forcing?

What about ice recovery and or tipping points? Need to carefully define tipping points, i.e. can the ice recover from a dramatic or abrupt change? Under what forcing conditions?

When/where/how is the ice-albedo feedback most/least effective?

What controls the heat buildup in the upper-ocean? Is there memory in the ocean as well as the ice and how can it be quantified?

What elements of the system lead to 2007 and to what extent are they predictable or random?

Can an ENSO/Hurricane-type regression method be developed for prediction? What can we learn from other efforts to predict?

What are the dynamic feedbacks in the system and how do they act?

Ice thickness redistribution. Could there be much thicker ice up against the Canadian Archipelago? Need for thickness surveys in Spring of 2008 to sample ice thickness in this area.

What is the relationship between ice age and thickness? What is the real ice age in the Arctic?

Predictions Working Group - Predictability Limits

We have very strong interannual variability about a longer trend.

Normal distribution of positive and negative ice anomalies. Does this

mean we have a 50-50 chance?

In the past, no year-to-year correlation in ice extent. Does this change

regionally? Has this changed with a thinner ice and dramatically

extensive pack? Do we have correlations in ice thickness? Age?

If answer to previous question is no, then prediction needs to be

prefaced by acknowledgment that past evidence suggests limited

predictability but that extreme event of 2007 may be associated with

conditions that hold promise for (empirical) predictions.

Predictions Working Group - Recommendations

Goal: Establish a consensus outlook for the May through September ice extent and ice characteristics.

• Outlook produced and revised monthly

• Solicit forecasts from different centers for “bake-off”.

• One moderator (group) who reviews forecasts and integrates information for

public release.

• In addition to forecast, provide detailed explanation of expected changes

and impacts. IMPORTANT!

• Derive/compile regional information specific to areas of interest to various

centers.

• Must involve international collaboration.

• After the event: Retrospective. Who got it right and why?

Predictions Working Group - Action Items

Discuss possible organizations (e.g. SEARCH, DAMOCLES, ISAC) to be a

home base for collecting information, moderating, and/or getting information out.

Solicit (limited) input on outlooks using template.

Develop some sort of repository for incoming data-stream (e.g. password

access WIKI).

Provide a blog for discussion. Ties to State of the Arctic?

Set a target date for first forecast/outlook (April 15th?)

2008 Sea Ice Outlook Template (SAMPLE)

1. What will the sea ice extent be at the September 2008 minimum?

1. (a) What will the sea ice situation be in September for:

(i) Bering/Chukchi/Beaufort Sea

(ii) Barents Sea

(iii) Northern Sea Route

(iv) Northwest Passage

1. (b) How will the sea ice situation evolve over the course of the summer (May-September) for:

(i) Bering/Chukchi/Beaufort Sea

(ii) Barents Sea

(iii) Northern Sea Route

(iv) Northwest Passage

2. On what is your forecast based?

3. What information are you lacking that might improve your forecast?