International Civil Aviation Organization

VAAC Best Practices SeminarSummary of Discussions

ICAO Headquarters, Montreal13 and 14 February 2012

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Background…

• A number of ICAO IAVWOPSG and IVATF conclusions between 2004 and 2011 have addressed aspects of harmonization and best practices.

• IAVWOPSG Conclusion 6/8 (19 to 23 September 2011):Workshop to develop VAAC best practicesThat Australia, in conjunction with WMO, be invited to facilitate a

workshop for all VAACs in 2012 or 2013 to share, develop and document VAAC best practices, in order to support harmonization of the VAACs’ operating procedures and to mitigate inconsistency for operators.

Note.— The workshop should consider all aspects of VAAC operations, including but not limited to, lead VAAC and coordination, emission source parameters, satellite analysis, trajectory and dispersion modelling and output. The outcome of the workshop should be presented as soon as possible and reported to IAVWOPSG/7.

VAAC Best Practices Seminar – Montreal – 13-14 February 2012

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Volcanic Ash Challenge Team (20/9/11):

Considering the needs for improved continuity between adjacent VAAC areas of responsibility, clarification of user requirements and assistance to VAACs in development and deployment of existing and new products, the VACT agreed as follows:

That the industry (IATA, ICCAIA, IFALPA) will work with the VAACs, through the IAVWOPSG, to develop a standardized product by June 2012 that meets the user requirements so as to allow for safe and efficient flight operations.

Action: IATA, ICCAIA, IFALPA

VAAC Best Practices Seminar – Montreal – 13-14 February 2012

Opening discussions...

• Presentations from ICAO and IATA on user requirements and expectations.

• In addition to harmonization and other requirements, the meeting also discussed and noted the importance of transparent and sustainable cost-recovery by VAACs. This may be essential to implement IAVW improvements.

Best practice questionnaire

• Each VAAC answered a wide-ranging questionnaire, with results kindly collated and analysed by New Zealand (see next slides).

• The issues identified were discussed, and break-out groups discussed themes in more detail.

Opportunities identified from questionnaire (1)

The questionnaire responses indicate a high standard of professional practice, and broad consistency in approach, across all the VAACs. There are a number of opportunities to further our collective capability…

• Collaboration on the application of observing techniques

– Satellite applications are a rapidly changing area and some VAACs may find it a challenge to stay at the cutting edge

– Sharing experiences with alternative methods – e.g., social media

• Lead VAAC concept may benefit from a common set of “rules of engagement”, so that VAACs benefits from cooperation without feeling a loss control over their AoR

• Training of staff in nominated backup centres, and routine testing of backup capabilities, appear to be areas of weakness for most VAACs.

• A more formalised approach to data exchange between neighbouring VAACs during events may simplify coordination efforts in complex situations

Opportunities (2)

• Sophistication of dispersion modelling at some VAACs is advancing rapidly – this may lead to an increasing gap in capability between VAACs

– Is the more advanced capability leading to better forecasts or products for end users?

– If so, can we ensure that all VAACs are able to deliver to a common standard in terms of modelling?

• Initialising an ATDM with an analysis to combine obs and modelling – a potential goal for “best practice” may be to enable this across all VAACs

• There is limited capability to deal with uncertainty in ash cloud forecasts, despite this being an area of interest for IATA. If we are ultimately to provide probabilistic information, how can this be done objectively?

• Should there be common standards for VAAC performance – e.g., minimum response times, verification of outputs? Cf IATA requests.

Opportunities (3)

• Minimum requirements for observational evidence before issuing or altering a VAA?

• Should there be a common approach to the “shelf life” of an existing VAA in the absence of supporting observational evidence?

• Should there be a common policy on complexity of ash layer descriptions in VAA?

• All of the VAACs except one operate with staff who have other operational duties. Recent challenging events (Iceland events, Cordon Caulle) have seriously stretched VAAC resources… perhaps it’s time for some of us to rethink our operational models?

Lots of issues….

• Focused on most important and achievable themes – low hanging fruit.

Low hanging fruit

Key themes

1. “Visible Ash” and how an area of ash is analysed (or forecast) in Volcanic Ash Advisories.

2. Data exchange, the role of the ‘Lead VAAC’, collaborative decision-making, and forecast validation

3. Articulating forecast confidence/uncertainty Increased mutual understanding Better outcomes

1. “Visible ash”, analysis, consistency etc

Detailed discussion shows that VAACs will do slightly different things based on their interpretation of the evidence available and Annex 3 / Handbook provisions, eg:

• Without satellite evidence but with other observations, will a VAAC attempt a full dispersion forecast or simply give winds?

• Advisory cessation• Following initial issue, advisory validity times

following standard cycle (0Z, 6Z, 12Z, 18Z), or matched to SIGMETs, or staggered for workload

“Visible ash”, analysis, consistency etcWhat “Visible Ash” is can be taken back to the

question posed by the AIR group in IVATF/2 (paraphrased) ‘what are the practices that have so far kept us safe?’

i.e. Given the evidence and modelling available in a situation, can we agree and document how VAACs will consistently, objectively produce ‘ash/no ash’ Volcanic Ash Advisories?

“Visible ash” defined?“Visible ash” – volcanic ash that, in the professional

judgement of the VAAC, is likely (or observed) to be detectable by human eye or remote sensing (using multi-spectral techniques) in good visibility conditions. This judgement will be based on agreement on best-practice, and also by further information from the OEMs on susceptibility of aircraft to ash cloud.

Ash that would not be observable in good conditions is not subject to the warning system and, for the purposes of all references to volcanic ash in SARPs etc, is ignored until agreed otherwise.

Resolving differences in practice• A paper will be prepared for IVATF/4

outlining how VAACs will converge further to common practice in matters relating to the handling of observations and modelling for marginal situations.

• Target for endorsement: IAVWOPSG/7.

Confidence Levels

• IATA proposal for Confidence Levels.– Confidence (High, Medium, Low)

• VAA level of confidence• Source term• Plume height• Lateral observed extent• Model output• Additional observation information

– Best Practices sub-team evaluated IATA proposal• Decided to apply confidence to T+0 polygon only at this

time.

15Project title (Insert, Header & Footer)

Confidence (2)• 3 confidence levels – High, Medium, Low• Walk before run

– Confidence levels applied to T=0 ash cloud position (polygon) of the VAA

– Future goal: Confidence levels applied to forecast positions (T+6 etc)

• Confidence levels do not apply to the VAAC capability, rather it is commentary on the current meteorological and volcanological environments

16Project title (Insert, Header & Footer)

Confidence (3)Confidence Level Criteria for T=0

High (meets all 3) •More than 2/3 of polygon contains identified/discernible ash cloud , and•Ash cloud edges( with respect to polygon) mostly (2/3) discernable, and•plume height and/or ash cloud top reported or measured (objectively) (e.g., Radar, Lidar, satellite, etc)

Medium (meets 2) •Between 1/3 and 2/3 of polygon contains identifiable/discernible ash cloud.•Between one third and two thirds of ash cloud’s edges discernable•Plume height and/or ash cloud top estimated from recent data (<12 hours)

Low •Less than1/3 of polygon contains identiable/discernable ash cloud.• Ash cloud edges uncertain.•Plume height and/or ash cloud top unconfirmed

17Project title (Insert, Header & Footer)

Confidence (4)

• How to get there?– Present to IATA– Present to IVATF– Hand off to IAVWOPSG– Possible solutions

• Include in Remarks section of text VAA and VAG

18Project title (Insert, Header & Footer)

Confidence (5) – future development• Initial thoughts on defining confidence levels

for forecast polygons. Look at:– Confidence level of the T+0 polygon.– Ability to define ESP (especially plume height).– Stable synoptic weather pattern (compared to a

complex pattern with fronts, strong wind shearing with altitude) and the handling by NWP models.

– New polygons consistent with previous forecast’s polygons. (e.g., old T+12 forecast = new T+6 forecast)

– Stratospheric vs Tropospheric eruption?19Project title (Insert, Header & Footer)

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3. Coordination across VAAC boundaries• To ensure consistency between VAACs (borders, layers, etc.)• Change ‘’LEAD’’ TO ‘’PRIMARY’’• Definition: PRIMARY VAAC is defined as the VAAC with responsibility

for coordinating the production of advisories for volcanic eruptions originating within its designated area of responsibility

• When an ash cloud ash approaches (550 km) another VAAC’S area of responsibility, the Primary VAAC will coordinate with the neighbouring VAAC to produce a seamless product covering the 2 areas of responsibility. ( Depending on circumstances, the 2 VAACs may issue their own VA but the PRIMARY VAAC will ensure consistency at the border (this is already permitted in Handbook)

• If the ash cloud moves into the area of responsibility of a third VAAC, the second VAAC is responsible for initiation coordination with

it. VAAC Best Practices Seminar – Montreal – 13-14 February 2012

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Coordination across VAAC boundaries (2)• GENERAL PRINCIPLE (closed door coordination between VAACs): If

differences arise between the originating VAAC and the other VAAC on the extent of the ash cloud, the latter will have final say over its area of responsibility.

• Where felt necessary, the coordination procedures may be established through written agreements between VAACs.

• Proposal: Paper to be submitted to IAVTF4 to modify Handbook of IAVW - develop ideas on coordination, primary and other VAAC , make hand off a separate section

• This will be done by members of IAVWOPSG (specific proposals for modifications to Handbook)

• Look and feel of VAG: is it possible to use the same map projection?• COLLABORATIVE TOOL WOULD - WILL HELP GREATLY

VAAC Best Practices Seminar – Montreal – 13-14 February 2012

Resourcing

• From the survey it seems that most of the VAACs are funded in the margins of their host organisations and that until recently little economic analysis has been done by those organisations to optimise their investment in this increasing important field.

• It is suggested that such an exercise would show scope for further investment in better staffing regimes and better access to technology and communications. This work could be achieved through a single consulting project on behalf all VAAC host organisations.

Resourcing (2)

• This is an issue that goes wider than the VAACs (eg WAFS)

• The seminar requests guidance (to IAVWOPSG?) from the ICAO Secretariat on how to progress these issues.

Follow-up

• This has been a very useful meeting. In practice, and noting budgetary and time constraints, it would be difficult to have a quick follow-up.

• Follow-up through IVATF & IAVWOPSG where possible

• WMO Volcanic Ash Workshop in March 2013 for science-related issues.