DV1,Q1a,Q1b,Q2a,Q2b,Q3a,Q3b,Q4a,Q4b,Q5,,,,,,Q6a,Q6b,Q7a,Q7b,Q8a,Q8b,Q9a,Q9b,Q10,,,,,,Q11a,Q11b,Q12a,Q12b,Q13a,Q13b,Q14a,Q14b,Q15,,,,,,Q16,Q17,Q18,,,,,,Q19,Q20,Q21,,,,,,Q22,Q23,Q24,,,,,,Q25,Q26,Q27,,,,,,,,,Q28,Q29,Q30,,,,,,Q31,Q32,Q33,,,,,,Q34,Q35,Q36,,,,,,Q37,Q38,Q39,,,,,,Q40,,,,,,H1a,H1b,H1c,H2a,H2b,H2c,H2d,H2d_open,H2_why,,,,,,H3,,,,H3_other,,H3_why,,,,,H4a,,,,,H4b,,,,,H4b,,,,,H5a,H5b,H5c,H5d,H5e,H5_other,H5_why,,,,,,H6,H7,,H8,H9,H10,H11
Survey_Number,VAAC_Path_A,VAAC_Conf_A,VAAC_Path_B,VAAC_Conf_B,VAAC_Path_C,VAAC_Conf_C,VAAC_Path_D,VAAC_Conf_D,VAAC_Paths_Open,VAAC_Paths_Open1,VAAC_Paths_Open2,VAAC_Paths_Open3,VAAC_Paths_Open4,VAAC_Paths_Open5,UKMO_Path_A,UKMO_Conf_A,UKMO_Path_B,UKMO_Conf_B,UKMO_Path_C,UKMO_Conf_C,UKMO_Path_D,UKMO_Conf_D,UKMO_Paths_Open,UKMO_Paths_Open1,UKMO_Paths_Open2,UKMO_Paths_Open3,UKMO_Paths_Open4,UKMO_Paths_Open5,SAT_Path_A,SAT_Conf_A,SAT_Path_B,SAT_Conf_B,SAT_Path_C,SAT_Conf_C,SAT_Path_D,SAT_Conf_D,SAT_Paths_Open,SAT_Paths_Open1,SAT_Paths_Open2,SAT_Paths_Open3,SAT_Paths_Open4,SAT_Paths_Open5,UKMO_Gap_Area,UKMO_Gap_Area_Conf,UKMO_Gap_Area_Open,UKMO_Gap_Area_Open1,UKMO_Gap_Area_Open2,UKMO_Gap_Area_Open3,UKMO_Gap_Area_Open4,UKMO_Gap_Area_Open5,UKMO_Solid_Area,UKMO_Solid_Area_Conf,UKMO_Solid_Area_Open,UKMO_Solid_Area_Open1,UKMO_Solid_Area_Open2,UKMO_Solid_Area_Open3,UKMO_Solid_Area_Open4,UKMO_Solid_Area_Open5,SAT_Gap_Area,SAT_Gap_Area_Conf,SAT_Gap_Area_Open,SAT_Gap_Area_Open1,SAT_Gap_Area_Open2,SAT_Gap_Area_Open3,SAT_Gap_Area_Open4,SAT_Gap_Area_Open5,SAT_Solid_Area,SAT_Solid_Area_Conf,SAT_Solid_Area_Open,SAT_Solid_Area_Open1,SAT_Solid_Area_Open2,SAT_Solid_Area_Open3,SAT_Solid_Area_Open4,SAT_Solid_Area_Open5,,,,GG_Path,GG_Path_Conf,GG_Path_Open,GG_Path_Open1,GG_Path_Open2,GG_Path_Open3,GG_Path_Open4,GG_Path_Open5,RG_Path,RG_Path_Conf,RG_Path_Open,RG_Path_Open1,RG_Path_Open2,RG_Path_Open3,RG_Path_Open4,RG_Path_Open5,RB_Path,RB_Path_Conf,RB_Path_Open,RB_Path_Open1,RB_Path_Open2,RB_Path_Open3,RB_Path_Open4,RB_Path_Open5,BB_Path,BB_Path_Conf,BB_Path_Open,BB_Path_Open1,BB_Path_Open2,BB_Path_Open3,BB_Path_Open4,BB_Path_Open5,Two_Model_More_Info,Two_Model_More_Info1,Two_Model_More_Info2,Two_Model_More_Info3,Two_Model_More_Info4,Two_Model_More_Info5,VAAC_Familiar,UKMO_Familiar,SAT_Familiar,VAAC_Trust,UKMO_Trust,SAT_Trust,Other_Trust,Other_open,Trust_Why,VAG_Trust,UKMO_Trust1,SAT_Trust,Overall_Trust,,Preference,Preference1,Preference2,Preference3,Preference_other,Preference_Cleaned,Preference_Why,Preference_Why1,Preference_Why2,Preference_Why3,Preference_Why4,Further_Info_VAAC,Further_Info_VAAC1,Further_Info_VAAC2,Further_Info_VAAC3,Further_Info_VAAC4,Further_Info_UKMO,Further_Info_UKMO1,Further_Info_UKMO2,Further_Info_UKMO3,Further_Info_UKMO4,Further_Info_Sat,Further_Info_Sat1,Further_Info_Sat2,Further_Info_Sat3,Further_Info_Sat4,Important_Content_Conc,Important_Content_location,Important_Content_altitude,Important_Content_timing,Important_Content_other,Important_Content_Other,Important_Content_Why,Important_Content_Why1,Important_Content_Why2,Important_Content_Why3,Important_Content_Why4,Important_Content_Why5,Sector,Job_Position,Sector_coded,Job_Years,Age,Gender,Further_Comments
101,0,9.8,0,9.8,0,9.7,0,9.6,No concentration levels-no past information-all paths too close to forecast region,Lack of information,Past Performance,Proximity,,,0,9.7,0,9,0,6.9,1,3.5,No information on future behavior (forward prediction) so uncertain how this will change,Lack of information,,,,,0,9.7,0,9.6,0,4.7,1,3.7,No future prediction so can't extrapolate (which way is the wind blowing and how will this change the forecast during the flight),Lack of information,,,,,,1.4,More complex initial condition so greater uncertainty on future behavior,Uncertainty,Gap,,,,,2.3,No information on future wind conditons so uncertain how region will change in next hours,Need more information,,,,,,3.5,Complex initial condition so more uncertain on how things will change,Gap,Uncertainty,,,,,4.9,wind direction uncertain,Need more information,,,,,,,,0,7.9,path near >4000 contour in model 2(rhs),Concentration,Comparison,Fuzziness in boundary,,,0,10,path through model 1 >4000 contour,Concentration,Comparison,,,,0,8.5,Path through model 1 >4000 contour-model 2 looks overconfident,Comparison,Concentration,,,,0,8.6,"path closest to model 2 >4000 contour. Although model 1 is far from contour, no details on model inputs provided, so no reason to suspect model 1 is more skillful",Comparison,Concentration,Need more information,,,"Details of model inputs, particularly source and met data. Observations and past performance of models.",Model input,Past performance of models,Observations,,,9,9.1,9.5,3.2,2.4,6.1,,,"VAGs are conservative models miss some physics, parameterized sources are poorly represented. Satellites don't see ash of all sizes.",Model inaccuracy,,Observation inaccuracy,,,,,,,,,"No preference, must be used together",No preference,Combined use,,,Add observations,Observations,,,,Add observations and uncertainty (particularly on source),Observations,Uncertainty,Source uncertainty,,"Add uncertainty-where is ash likey to be missed, what is the confidence in retrieval?",Uncertainty,Confidence,,,2,1,3,4,,,"All are important; depending on requirement of forecast the ranking will change. Also, the uncertainties are coupled-timing leads to positional and conentration errors, etc.",All important,Depends on situation,Interdependency,,,Academic research,Postdoctoral research assistant,Research,6,35,Male,
102,0,10,1,6.5,1,9.7,1,9.9,A length of time in target area,Exposure,,,,,0,9.7,1,9.8,1,9.7,1,9.7,BCD yes as only short time in medium,Exposure,,,,,0,9.9,1,8.3,1,9.9,1,9.9,Time over target,Exposure,,,,,,8.3,2 nfzs allows corridor into out of LHR,Gap,Reduction of disruption,,,,,7.7,"good for current flights/flights approaching departing from LHR, however this nfz will expand east based on forecast winds",Need more information,,,,,,9.2,Stay outside red area,Concentration,,,,,,8.1,area greater than red to allow for uncertainty,Margin,Uncertainty,,,,,,,1,6.7,approve but extra fuel loaded for [unintelligible] 2 in case of in flight diversion,Comparison,Assumption,Diversion,,,0,8.3,Flight path needs to be adjusted to the north,Diversion,,,,,0,9.3,"load extra fuel, adjust to the north",Diversion,,,,,0,9.1,adjust flight path more to north,Diversion,,,,,A SAT image of the situation,Observations,,,,,10,10,10,5.5,5.3,8.8,,,,,,,,,"2, 3",2,3,,,5,More easily understood for planners,Easier understanding,,,,Concentration loads of ash included,Ash concentration,,,,Altitude/3d/image,Altitude information,3D Visualization,,,Levels/3D,Altitude information,3D Visualization,,,1,3,2,4,,,Uncertainty of concentration allows for greater nfz area,Affects decision the most,,,,,flight operations,operation [unintellibile],Operations,3,56,Male,n/a
103,0,9.8,0,9.8,0,9.8,0,9.8,Again the green VAG line is forecast discernable ash; the OEMs and EASA say to avoid discernable ash. Even flight path D is too close to discernable ash for comfort,Proximity,,,,,0,9.7,0,9.7,0,9.7,0,9.7,"My knowledge of how little we know of ash engine damage effects, and because EASA say \avoid discernable ash'; ash is discernable at 200 ug/m3",Proximity,Exposure,,,,0,9.8,0,9.8,0,9.8,0,9.7,See answers to previous two pages,Proximity,Exposure,,,,,9,Confidence over the original concentration prediction plus some margin,Concentration,Margin,,,,,8.5,I've used the forecast plus some margin,Margin,Concentration,,,,,9.7,See answer on previous page,Concentration,,,,,,9.5,It all comes back to the position and avoiding discernable ash (EASA + OEMS),Concentration,,,,,,,,0,9.7,Because EASA and OEMS have said to avoid discernable ash (~200 ug/m3),Assumption,Concentration,,,,0,9.5,See previous answer,Assumption,Concentration,,,,0,9.8,See answer on previous page,Assumption,Concentration,,,,0,9.5,See answer from previous page,Assumption,Concentration,,,,"This is a complex problem, but there is a possible solution. OEMs need to define an acceptable exposure dose (x ug/m3 x time) if this can be demonstrated at a high enough does e.g. 10,000 ug/m3 for one hour, and exclusion zone can be defined outside of which the probability of exposure to a dose >10 mg/m3 for an 1 hr is < 10^-9 flight hours",Engine information,,,,,9.7,9.7,9.8,9.8,1.5,5.5,1.8,WSI products,"The VAG is great, once you realize what it represents. Ash concs are not good and very misleading. Satellite retrievals are between 0.1 -> 0.9 accurate.",Understand Meaning of Graphic,Distrust,Observation inaccuracy,,,"1,3",1,3,,Total column loading forecast (g/m2),5,"The VAG is fine; it gives an indication of where discernable ash will be. For risk-based flying, a total column loading forecast is more accurate than conc forecasting and isn't misleading.",Just need location information (certainty in simplicity),Column loading,,,See (participant) presentation in afternoon,,,,,Of very limited value,Graphic of very limited value,,,,Much more useful,Nothing,,,,5,5,5,5,,,"I have a fundamental problem using forecast uncertainty. If the best people in the world (VAACs) are not confident, are you really going to take the risk?",Scared of uncertainty,,,,,Engine Manufacturer,Capability lead engine environmental protection (i.e. protecting engines from the environment),Operations,5,53,Male,Clearly the aviation world hasn't trigged what's been happening amongst OEMs and regulators since 2010
108,1,3.5,1,8,1,9,1,9.8,"Area is a medium forecast. Approved to fly in medium area, but not visual ash, therefor confident that any visual observations would be reported and I can then avoid",Proximity,,,,,0,7.3,1,5,1,7.3,1,9.8,Looks the same as previous graphic therefore same decision,Proximity,,,,,0,7.8,1,5.2,1,7.8,1,9.8,The greater granularity of the concentration data persuaded me that route a may result in breaking approval and force crews to confront 4000 ug densities,Proximity,,,,,,10,An operator may have approval to fly in high forecasted areas of ash and therefore a 'no fly zone' is not appropriate,Assumption,,,,,,10,"Flight approved into medium areas of ash-therefore for this particular flight, no plan of entering area of high. However, this is not a no fly zone for all high.",Concentration,,,,,,10,In policy terms for this flight only areas of high concentration should not be planned to fly trough,Concentration,,,,,,10,For this particular flight it should not plan to fly in forecasted areas of ash >4000,Concentration,,,,,,,,1,9.9,"My plan does not enter forecasted high concentration. If situation changes in flight, I can avoid",Concentration,Assumption,Certainty in boundary,Diversion,,0,8.8,"My approval does not permit flight in forecasted high ash, the Safety Assessment should take into account all data so I would fly via Denmark and avoid worst case area of ash.",Diversion,Fuzziness from comparison,Concentration,,,0,9.8,"I have data, albeit contradictory, that indicated I may encounter high concentration therefore breaching safety risk assessment approval",Comparison,Concentration,,,,1,10,"Again, my flight approval is sill valid for both charts. If ash is encountered, can avoid. Forecast indicated only medium would be encountered",Diversion,Comparison,Concentration,,,A single model would help with an agreed method of fussion,Less information,,,,,10,10,1.8,4,4,4,,,"Forecasts are forecasts only.Although experience has shown they are conservative, I don't know the provinence of the satellite ash retrieval to comment",,,Unknown provinence Source Data,Forecast Error,,4,4,,,,4,I prefer the one that I am told is the most accurate and least distructive to air traffic,External Authority on accuracy,Convenient message,,,"It is what it is, a forecast, better source data results in better output",Better source data,,,,"Again, mre robust source data may make the model more accurate",Better source data,,,,I am not familiar with the what and how that the graphic is presenting to judge.,Explanation of graphic,,,,1,2,3,4,,,"Presenting degree of uncertainty in a model wil plant the seed of greater uncertainty. Really want consistent forecast so that regulatory and policy judgements can be made. We are regulated on concentration so understanding margin of error useful, followed by location error.",Scared of uncertainty,Affects decision the most,Relevance to Industry,,,ATM,Operatoinal Policy,Operations,8,54,Male,
116,1,0.8,1,2.2,1,8.3,1,10,The areas shows areas of any VA therefore based on the information given the flights following all of the flight paths are able to operate however with varying levels of uncertainty depending on the length of time exposed,Proximity,Exposure,,,,0,10,0,8,1,10,1,10,Flight path A crosses 2 areas of VA over the approved concentration levels. The concentraton reduces outwards so the flight paths at the extremeties are more suitable,Proximity,,,,,0,10,0,10,0,3,1,10,The ash density in the red area is much greater than the other areas therefore flight paths A and B are not suitable for this flight,Proximity,,,,,,5,There are two areas of high concentration and the area inbetween are at a lower concentration. I have drawn over the whole area to reduce the possibility of flying through an area of high concentration. ,Concentration,Gap,Margin,,,,8.5,The area >4000 ug/m3 is clearly marked so a confident decision can be made when forecasting a no fly zone,Concentration,,,,,,2.5,"Again, the wind has not been factored into my recommendation and the areas of highest concentration appear not to be where the volcano would be strongest",Need more information,Concentration,,,,,5,Based on the approved level of volcanic ash concentration I have drawn around the red and orange areas. My reason for uncertainty is that the wind and concentration trend has not necessarily been taken into consideration,Concentration,Need more information,,,,,,,1,6.8,The flight path does not cross the area of highest concentration on either model however given the proximity to the high concentration there is reduced certainty of flying through medium level,Certainty in boundary,Concentration,Fuzziness in boundary,Comparison,,1,6,The model with the highest forecast concentration has the path crossing a small area. This does not state which altitude the highest concentration of ash will be encountered.,Comparison,Concentration,Assumption,,,1,6.3,"One model allows flight through the area at a lower level of concentration than approved however the other model does not. Based on this, a there is a chance that one may be incorrect",Comparison,Concentration,,,,1,9.3,The flight path does not cross the area of highest concentration on either model,Certainty in boundary,Concentration,Comparison,,,Altitude information,Altitude,,,,,10,7.5,0.6,10,10,10,8.2,Pireps,The VAG and modelled ash concentration are based on wind forecasts. Satellite ash retrieval is based on the reflection picked up by satellites,Knowledge of source information of graphic,Knowledge of source information of graphic,Knowledge of source information of graphic,,,1,1,,,,1,I have the most confidence based on previous VAG events in these graphics,Past performance/experience,,,,More corners and less polygonal shapes,Higher resolution,,,,Altitude information,Altitude information,,,,More clearly defined boundaries,Boundary definition,,,,1,3,2,4,5,Uncertainty in how it will affect airframes/engine,The density needs to be the most accurate forecast,Affects decision the most,,,,,Airline,Flight planning,Operations,3,29,Male,
121,0,8.5,0,8.5,0,8.5,1,4.5,Lack of definition and info,Lack of information,,,,,0,10,1,5.5,1,10,1,10,Definition around transition between high and medium not clear,Lack of information,,,,,0,10,0,7,1,7.8,1,10,Uncertainty around the definition of the areas drive caution,Uncertainty,Proximity,,,,,4.5,As before,Assumption,,,,,,4.5,As before,Assumption,,,,,,4.3,Based on our ability to establish a no fly zone within our flight planning system,Assumption,,,,,,4.5,"As before, system limitations for flight planning",Assumption,,,,,,,,0,5,"Without futher info, the flight path risk encroaching red. Would need to verify position of high concentration relative to company procedures",Need more information,Fuzziness in boundary,Concentration,,,0,5.8,Variation between the two is too much,Comparison,Fuzziness from comparison,,,,0,5.3,"Again, too much variation",Fuzziness from Comparison,Comparison,,,,0,5.5,Too much variation between the two models,Comparison,Fuzziness from comparison,,,,"Satellite overlay, plus calculated distances of transitions between one zone and another would allow us to plan against safety case. Also, dispersion at different flight levels would allow us to consider over/under flight",Observations,More bins,Altitude,,,5.5,9.5,9.8,6.5,8.3,9.8,,,Really based on familiarity,,,,Familiarity,,3,3,,,,3,SAR can be used to validat models,Observational accuracy,,,,The lack of definition to the boundaries raises the question of accuracy,Higher resolution,,,,"The defined area is better in MACC, but definition around the transition from zone to zone can lead to uncertainty",Boundary definition,,,,/,,,,,4,1,3,2,,,"Knowing where the ash is, helps to take immediate precautions around safety (if necessary). Once you have established that you can then refine your plan based on density variations an daltitudes",Affects decision the most,,,,,Airline,Operations,Operations,3,46,Male,
122,0,7.8,0,7.7,0,7.7,1,9.9,"Based on the lack of information relating to ash concentration, I would be relatively confident in my decision. Whilst more conservative than a chart with differing levels, this could have an economic impact, but potentially lower risk",Lack of information,,,,,0,8.2,0,2.4,1,8,1,9.5,"Any flight path going through known >4000 ug/m3 would stop me from approving the flight. Also, the potential for the ash concentrations to move due to winds aloft.",Proximity,Lack of information,Assumption,,,0,9.8,0,4.2,1,8.6,1,9.9,The color gredation on the chart lead me to believe there may be an increased risk of exposure to +4000 ug/m3 areas. Again the poential for differences due to the winds aloft affected my choice,Proximity,Assumption,,,,,7.4,The no fly zone covers areas where ash concentration is >4000 ug/m3,Concentration,,,,,,8.2,"As before, no fly zone matches area of >4000 ug/m3 concentration",Concentration,,,,,,4.8,The area encompasses all areas of concentrations of +4000 ug/m3. Additionally it covers the area in between the two highest areas of concentration,Concentration,Gap,,,,,4.9,"This no fly zone covers all areas that are represented as containing concentrations of 4000 ug/m3 or higher, including the 4000 ug/m3 level.",Concentration,,,,,,,,1,4.7,"Both flight paths remain clear of the highest level zone, however some uncertainty due to the proximity to the highest level, bearing in mind that these are only forecasted graphics",Comparison,Concentration,Fuzziness in boundary,,,0,7.4,I would opt to utilize the most restrictive charting to minimize exposure to risk. ,Comparison,,,,,0,2.6,"Same reasons as previously, however I am less confident in my decision due to how much the two forecasts differ",Comparison,Fuzziness from Comparison,,,,0,8.4,"Whilst there would be a commercial impact on the airline, working with the most restrictive charting would/should provide the highest level of safety and risk mitigation",Comparison,,,,,"Additional weather information overlays (for instance jet streams, winds aloft, etcó) Vector arrows outlining the direction and speed of ash cloud movement",Wind information,,,,,10,5.7,7.3,7.3,5,5.2,,,"The VAGs in addition to representing ash cloud areas display levels and different time periods. However they don't represent the various ash concentrations. Ultimately, they need to be used together to build a more complete picture.",,,,Trust when used in unison,,1,1,,,,1,Time and different flight levels represented,Altitude information,More granularity in forecast period,,,Areas of varying concentrations. Winds aloft/jet stream/weather overlay,Ash concentration,Meteorological information,,,Forecasted ash cloud movement. Winds aloft/jet stream/weather,Meteorological information,Time series,,,"Forecasted ash cloud movement. Winds aloft, jet stream graphical representations.",Time series,Meteorological information,,,2,1,3,4,,,,,,,,,Airline industry,Pilot,Operations,2,31,Male,
123,0,10,0,9,0,5.5,0,2.2,All flight paths go through or close to a level of ash which is unknown ,Proximity,Lack of information,,,,0,10,0,7.5,1,5,1,8,More confident in decision to avoid >4000 ug/m3 and to allow flight in 2000 or close to 2000-4000,Proximity,,,,,0,10,0,7.7,1,5.7,1,8.2,Forecast density along flight path. Conservative approach due to uncertainty in forecast and potential for ash cloud to move,Proximity,Uncertainty,Assumption,,,,1.6,Avoiding red zone and allowing a good margin around 2000-4000 2 red zones could confine,Concentration,Margin,,,,,5.3,Good margin around red/grey zones for uncertainty. Red zone fairly large,Margin,Concentration,,,,,7.4,Conservative to allow for potential movement of ash cloud during flight. Band of lower concentration is narrow.,Assumption,Concentration,Gradient,,,,6.7,"Some margin for movement of cloud, etc. but high concentration area smaller so prepared to go closer to lower concentration bands",Assumption,Concentration,Gradient,,,,,,0,8.9,Flight path either close to red zone or through grey for extended period,Comparison,Exposure,,,,0,9.8,Significant risk of flight through red zone,Concentration,,,,,0,10,Models predict flight through red zone or through blue for extended duration,Comparison,Exposure,Concentration,,,0,10,One prediction permits flight very close to the red zone with more optimistic model still close to grey,Comparison,Concentration,Fuzziness in boundary,,,Predicted concentration for period of flight to determine likely movement of ash. Reports from other aircraft close to flight path,Observations,Time series,,,,5.6,5,1.5,3.6,2.7,7.2,,,Sattelite data is observed with less modelling uncertainty,,,"observation accuracy, model accuracy",,,3,3,,,,3,As above (Satellite data is observed with less modelling uncertainty),Observational accuracy,,,,How is situation changing with time. Series of images around of interest,Time series,,,,As above,Time series,,,,As above,Time series,,,,4,1,2,3,,,Where it is geographically and altitude is key factor,Affects decision the most,,,,,Aerospace industry,Air worthiness specialist,Operations,15,49,Male,
124,0,0,0,0,0,5,1,9.9,"No info on ash concentration, no info on probability -> choose safest option for passengers",Lack of information,Uncertainty,,,Lack of Uncertainty Information,0,9.9,0,9.9,0,5.3,1,10,Safety of passengers is priority,Proximity,,,,,0,0.2,0,5.1,1,10,1,9.9,"Extent of plume, safety of passengers",Proximity,,,,,,9.9,No info on FC skills -> I assumed high skills of model FC. Lack of info on probabilities -> had to choose safest option,Past Performance,Assumption,Uncertainty,,,,10,Same as previous answer,Past Performance,Assumption,Uncertainty,,,,10,I have to choose the safest option,,,,,,,10,Need to stay clear of 2000-4000 shaded areas,Concentration,,,,,,,,0,4.6,Same as before,Need more information,Uncertainty,,,,0,4.7,Same as before,Need more information,Uncertainty,,,,0,5.1,Same as before,Need more information,Uncertainty,,,,0,7.3,This is a 50/50 scenario. Would need more info on uncertainty -> I had to choose safest option,Need more information,Uncertainty,,,,Info on model skills. More detailed info on probabilities of scenarios,Past performance of models,Uncertainty info,,,,9.9,9.9,10,,,,,,,,,,,,2,2,,,,2,Modeled ash concentration can be used in FC mode and therefore help planning,Concentration information,Compatible with systems already in place,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,Services (international),Scientist/liaison officer,Research,16,54,Female,
125,1,1.7,1,5.9,1,7.6,1,9.4,Closeness to boundary of medium ash boundaries. Closeness to volcano source.,Proximity,,,,,0,6.9,1,7.3,1,8.9,1,9.4,could see that >4000 was outside limits so cannot fly. Closeness to boundaries. Closeness to volcano source,Proximity,,,,,1,8.9,1,8.8,1,8.8,1,8.7,This is observational data and will not be valid by the aircraft gets to the ash location,Lack of information,,,,,,6.7,There is no such thing as a 'no fly zone' aircraft operators assess the information and make a risk-based assessment on likelihood of encountering ash,Assumption,Concentration,,,,,7.2,See previous answer regards to no fly zone,Assumption,Concentration,,,,,7.7,"This is observational data so cannot be easily used for flight planning, however aircrafts should avoid area higher than 4000 ug/m3",Assumption,Concentration,,,,,7.4,"This is observational data so cannot be easily used for flight planning, however aircrafts should avoid area higher than 4000 ug/m3",Concentration,Assumption,,,,,,,1,7.9,Both models show that ash >4000 ug/m3 can be avoided,Certainty in boundary,Concentration,Comparison,,,1,2.6,Aircraft can flight plan however the likelihood of encountering visible ash is much higher in the first image,Concentration,Comparison,Diversion,,,1,3,See answer to prevous answer,Concentration,Comparison,Diversion,,,1,7.6,Forecasts show that aircraft is less likely to encounter visible ash,Concentration,Comparison,,,,Confidence in forecast. Previous results (verification). Check with observational data. Probability of encountering visible ash however this assumes aviation industry knows the tolerance of ash concentrations,Past performance of models,Observations,Uncertainty info,Engine information,,10,10,10,8.6,8.5,9.4,10,Other observational data,Information is best that can be provided. There are no other sources that are more trustworthy,,,,No alternatives,,"2,3,4",2,3,4,Observational data,5,All three are needed to make risk-based assessments,Combined use,,,,Better definition on what this provides,Explanation of graphic,,,,Understanding of how this can be used to make risk based assessments,Explanation of graphic,,,,Understanding of how this can be used to make risk based assessments,Explanation of graphic,,,,1,2,4,3,5,Confidence in forecast,"Need to get concentration correct, then areal coverage, then accurate time-altitude also needed. Forecast confience is also of value.",Affects decision the most,,,,,CAA-Civil Aviation Authority,"Principal met, aeronautical information and radio licensing",Operations,10,53,Male,
126,0,6,0,4.6,0,4.7,1,3.5,"extent of the ash, I'm not a specialist. The concentration levels do not mean anything to me.",Proximity,,,,,0,8.4,0,2.4,1,2.7,1,6.5,Definition of contours,Proximity,,,,,0,8.3,0,8.4,0,8.5,1,2.3,Ash density profiles/shading,Proximity,,,,,,7.4,keep to min ash level contours to allow for uncertainty in the data and possiblity of multiply flight and associated uncertainty,Concentration,Uncertainty,Assumption,,,,7.2,Minimize dosage of ash and allow flight time around the region,Exposure,Assumption,,,,,7.4,Keep to within less than 2000 plot gives clear definition of bounds and shows resolutions,Concentration,,,,,,6.6,"Keep to 1000 or less, assume that shorter route may be outside the zone",Concentration,,,,,,,,1,6.7,There is sufficient margin to less than 4000 ug/m3,Certainty in boundary,Concentration,,,,1,7.7,Margin to less than or equal to 4000 ug/m3,Concentration,Certainty in boundary,,,,1,7.4,Good margin to <= 4000 ug/m3,Concentration,Certainty in boundary,,,,1,9.1,Good margin to <=4000ug/m3,Concentration,Certainty in boundary,,,,Would be better to have plots to show variability in the countours,More bins,,,,,0.6,0.7,0.4,2.4,3.9,4.9,,,Tend to trust more if there's an apparent resolution of contrast (color or shading),,,,More detail therefore more trust,,3,3,,,,3,"good resolution, actual observations",Observational accuracy,Concentration information,More concentration bins,,More detail about what is inside the enclosed regions,More information,,,,Would need evidence of validation/verification of the model against say satellite observation,Past performance,Observations,,,Would be good to a model forecast alongside it just as double check that it is as might be expected,Model forecast in addition,,,,1,2,3,4,,,Need to see that can pass through all the constraints in the order given,Affects decision the most,,,,,Industrial Mathematics,"Manager, Smith Institute",Research,5,60,Male,Very interesting! Very much focused on graphically presented information. Little on text information would it lead to different decisions?
127,0,10,0,10,0,8.8,0,7.3,lack of concentration structure/level/lack of upper wind forecast (okay so now means now) lack of VMC info,Lack of information,,,,,0,10,0,5,1,8.7,1,10,The possibility/risk of shift due to upper winds. VMC only i.e. no delays,Lack of information,Assumption,,,,0,10,0,10,1,7.5,1,9,Nearest threat point VFR [Visual flight rules] conditions/daylight,Proximity,,,,,,4.3,From shape of plume assuming winds from 280 degrees/300 degrees therefore greatest risk downwind,Assumption,,,,,,8,,,,,,,,7.5,Although subject to movement there are areas of VFR conditions,Concentration,,,,,,7.5,,,,,,,,,,1,7.8,Good model correlations/confidence plus warn even if threat,Comparison,,,,,0,5,As previous chart,Need more information,Comparison,Fuzziness from comparison,,,0,4.3,"Poor model correlation-lack of confidence if good VFR reported, maybe so need to check satellite imagery",Need more information,Comparison,Fuzziness from Comparison,,,1,6.5,VFR check needed very short risk exposure,Need more information,,,,,Previous reports historical progress of verified loads of concentration. Satellite imagery,Past performance of models,Observations,,,,4,4,0,2.5,3.5,,,,,,,,,,,,,,,,"My preference would be to have all. My first ""look"" would be b",Combined use,,,,Dynamic replay (to display specifics for chosen flight height),Time series,,,,Dynamic replay (to display specifics for chosen flight height),Time series,,,,Dynamic replay (to display specifics for chosen flight height),Time series,,,,1,2,3,4,,,,,,,,,Manufacturing,Operational safety advisor,Operations,4,69,Male,
128,,,,,,,,,No information about concentration! No information about uncertainty of line position,Lack of information,Uncertainty,,,Lack of Uncertainty Information,,,,,,,,,Perception of precision from graphic-bounds give impression of uncertainty. Assumption that forecast and approval working in conjunction,Uncertainty,Assumption,,,,,,,,,,,,Poor resolution and no uncertainty given on measured data,Lack of information,Uncertainty,,,,Lack of uncertainty information,0.5,"Aircraft not approved above 4000 ug. Forecast must provide for uncertainty within its representation, i.e. how probability that it will be wrong!",Uncertainty,Concentration,,,,,0.5,Knowing that there will be error in ability to forecast both position and amount of ash means that I continue to have low confidence,Assumption,Concentration,,,,,1.7,Same as before,Concentration,Uncertainty,,,,,1.7,Assumption that anything above 3000 might be closer to 4000 than 3000- again resolution of the technique not helpful,Concentration,Uncertainty,,,,,,,1,0,"Both models showed no issue, but fact that they show position very differently leads to perception of big uncertainty on position",Comparison,Fuzziness from comparison,,,,0,8.1,Large spread of model,Comparison,Fuzziness from comparison,,,,0,7.3,Variability of concentration/position means that model cannot be trusted in these circs,Comparison,Concentration,Fuzziness from Comparison,,,1,1.3,Both models show flight in safe zone. Again spread of position means that have lower confidence,Comparison,Concentration,Fuzziness from comparison,,,Expression of model uncertainty in some way form both amount and position,Uncertainty info,,,,,2.6,3.5,4.7,5.2,2.8,7.8,,,Satellites are measurements. VAG has effectively built uncertainty in somehow. Modelled ash looks nice but is uncertain and doesn't display this,Built in uncertainty,No built in uncertainty,Observation accuracy,,,3,3,,,,3,Because it tells me where the ash is! Not much use for planning thoughó,Observational accuracy,,,,Hmm. I think it's fit for purpose in that it is conservative,Nothing,,,,"Uncertainty displayed, both amount and position. ",Uncertainty,,,,Uncertainty in values (amount) of ash,Uncertainty,,,,3,5,2,4,1,,If you know when/where the ash is then you can avoid it and no matter the concentration,Affects decision the most,Pragmatic Approach,,,,Atmospheric observation research,Head of facility,Research,2,40,Male,
129,0,8.7,0,8.8,0,2.2,1,2.4,"Since there's no information on ash concentration, I erred on the side of caution, but let D through as it is right on the edge",Lack of information,Proximity,,,,0,8,0,4.3,1,6.4,1,7.9,Same as first question. Likely spread of cloud to the east rule out A and B but C and D are along the edge. Graphic easy to use but not as informative as the first one [satellite],Proximity,Lack of information,Assumption,,,0,8.5,0,7.3,1,2.7,1,6.2,1. Reading forecast ash density along path: greater than 4000 ug/m3 is no go. 2. Estimate of likely movement of cloud-it is spreading away from the volcano and I would be concerned about its eastward spread,Proximity,Assumption,,,,,4.7,"No fly should be >4000. I applied a margin of error extending into the grey zone, and into the blue zone at the eastern extent. I would need a wind field to do this more accurately",Concentration,Margin,Need more information,Assumption,,,,,,,,,,,5.2,"Around red zone with a margin of error, as before",Concentration,Margin,Uncertainty,,,,4.8,"Around the red zone with a margin of error, especially at the eastern end",Concentration,Margin,Uncertainty,,,,,,1,4.4,"Although there is a chance of >4000, this would only be for a very short time and the engine damage is cumulative. Risk is therefore low.",Concentration,Exposure,,,,0,5.6,There is a significant risk here of a lengthy period in ash concn >4000; indeed we don't know from this diagram how much greater.,Concentration,Exposure,Need more information,,,0,5.9,"Even though the second model shows a much reduced risk, the first one still shows an unacceptable risk. So the cautionary principle applies",Comparison,,,,,1,4.8,"As before, lightly accumulated ash concentration is small even if concentrations exceed 4000 for a short time",Concentration,Exposure,,,,"Wind speed and direction at flight level, ensemble forecasts",Wind information,More model outputs,,,,0.2,7,2.5,3.8,4.9,7.8,,,"The first is crude and gives no information on ash concentration. The second doesn't say which flight level, and is again a model product. The third is from measurements but the satellite can't see ash before cloud and is a column total, not a concentration",Lack of ash concentration,"Lack of altitude, Model inaccuracy","Observational accuracy, observational inaccuracy",,,2,2,,,,2,In principle this is the most useful product of the three as it gives an indication of concentration gradients and is a measure of the thing of what we want to know,Concentration information,,,,Indication of concentration,Ash concentration,,,,"Wind field, more contour levels where is the concentration really high?",Meteorological information,Higher resolution,,,It is what it is. I wouldn't change the graphic,Nothing,,,,4,3,2,5,1,Uncertainty in initial conditions of forecast,Altitude is crucial-if we can send planes above or below ash they will be safe. Next is the geographic location for the same reason. Concentration uncertainty will expand the no fly zone. Timing uncertainty is probably small-much smaller than initial condition errors,Affects decision the most,,,,,University,Usually Sedintary! (Professor of Atmospheric Science),Research,11,61,Male,
130,0,8.6,0,8.6,0,8.6,0,5.3,As before-bright lines v. dangerous,Proximity,Uncertainty,,,,0,9.8,0,9.9,0,9.8,0,9.3,"As before, high concentrations of predicted ash, uncertainty at low concentrations/ashes, no engine tests",Exposure,Proximity,Uncertainty,,,0,9.9,0,9.9,0,9.9,0,9.2,"High ash loading, uncertainty at cloud edges, no engine tests!",Proximity,Uncertainty,,,,,6.9,The boundary is 100km from the cloud edges. My answer would depend on flying conditions/visibility,Margin,Need more information,,,,,6.9,As previous,Margin,Need more information,,,,,8.7,As before,Margin,Need more information,,,,,8.6,As before,Margin,Need more information,,,,,,,0,8.7,"Again, uncertainty is too great. Even for more ""conservative"" flight path, the model need only be fractionally off (considering length of run) for flight to be compromised",Comparison,Fuzziness in boundary,Fuzziness from comparison,,,0,9.2,"As before, presence of >4000 ug/m3 ash in a definitive red line",Comparison,Uncertainty,Fuzziness from comparison,Concentration,,0,8.8,Uncertainty high in these models. One shows flight through no fly concentrations,Comparison,Uncertainty,Fuzziness from Comparison,Concentration,,0,8.3,"Again, flight across >2000 ug zone. I'm not convinced we know an engine would survive this",Concentration,Assumption,,,,"Some visualization of uncertainty!! That models disagree is unsurprising, no basis for judgment as to which one to weight. In this case, flight paths look too holey anyway",Uncertainty info,,,,,7.6,8.1,10,6.6,7.9,9.3,,,"VAGs are a little vague (for me) models (in native output) appear to have more information. Observation, where possible and of high fidelity, are some version of 'the truth'",Lack of information,Ash concentration information present,Observation accuracy,,,3 (depends what I'm using it for!),3,,,,3,potentially accurate snapshot in time BUT useless for forecasting,Observational accuracy,,,,Confidence interval (explicitly stated),Confidence,,,,Height resolved information? Some description of likely altitude/depth of plume,Altitude,,,,"Again, 3D view useful. Those numbers are burdens",3D  Visualization,Lower resolution,,,1,3,2,4,,,"They're all important, so it's a little arbitrary",All important,,,,,University,Reader,Research,3,42,Male,
131,0,8.8,0,5.5,0,2.1,1,7.5,Minimize time in ash cloud or avoid it,Exposure,Proximity,,,,0,9.7,0,4.9,1,1.4,1,7.5,Less than 2000 ug/m3 will be okay. Close to 4000 is higher risk. >4000 will not be okay.,Proximity,,,,,0,9.2,0,5.1,1,5,1,8.6,Being well clear of level >=4000,Proximity,,,,,,4.9,Reliability of forecasts? Time dependency of forecast. Narrower 200-2000 zone in places. Narrower 2000-4000 zone in places.,Past Performance,Concentration,Gradient,,,,4.1,Reliability of forecast? Narrower 200-2000 ug/m3 zone in places,Past Performance,Concentration,Gradient,,,,4.6,Uncertainties of analysis/forecast. Narrower zones <= 4000ug/m3,Uncertainty,Concentration,Gradient,,,,4.7,Uncertainties of analysis/forecast. Narrower zones <= 4000ug/m3,Uncertainty,Concentration,Gradient,,,,,,0,4.6,too close to >=4000 ug/m3 in right side model,Concentration,Comparison,Fuzziness in boundary,,,0,6.4,Crosses >=4000 in left side model and close to it in right side model,Concentration,Comparison,Fuzziness in boundary,,,0,6.2,Crosses through >=4000 ug/m3 in left model,Comparison,Concentration,,,,0,4,Close to >=4000 ug/m3 in right side model,Concentration,Comparison,Fuzziness in boundary,,,Model validation data. Error analyses of models.,Past performance of models,,,,,2,2.6,0.7,2,2.1,2.1,,,Not seen any evidence of validation in multiple events,,,,Lack of past performance information,,2,2,,,,2,May give some indication of uncertainty,Perceived that uncertainty is shown,,,,Validation and confidence in model,Past performance,Confidence,,,Validation and confidence in model,Past performance,Confidence,,,Validation and confidence in model,Past performance,Confidence,,,3,1,2,4,,,1. Need to know where ash is. 2. Need to know where ash is. 3. How much ash is less important (assuming uncertainty over safe levels) 4. Gives idea of error in position/quality-maybe,Affects decision the most,Pragmatic Approach,,,,Academic,Reader,Research,4,54,Male,Is any level of volcanic ash safe to fly though? Confidence in 2000-4000 ug/m3 range?
132,0,8.1,1,2.2,1,6.9,1,7.9,"Time spent in the cloud, proximity of edge of cloud from takeoff, constant altitude, assuming constant-ish concentration",Exposure,Proximity,Assumption,,,0,7.7,1,1.4,1,7.5,1,7.6,As before,Exposure,Proximity,,,,0,7.9,1,2,1,6.8,1,7.8,As before,Exposure,Proximity,,,,,5.8,As before,Assumption,Concentration,,,,,5.6,"low concentration (bottom end) can be found in highly polluted urban areas-so should be reasonably okay for flight. Bottom end of ""medium"" conc (2000 ug/m3) extends over most of the area. Variation of plume concentration may extend ""medium"" into ""low"" areas as well",Assumption,Concentration,,,,,6,As before,Assumption,Concentration,,,,,5.9,As before,Assumption,Concentration,,,,,,,1,6.4,"Both models predict no time spent in concs >4000 ug/m3. Even though second prediction is close to high conc, time likely to be exposed should be relatively low.",Comparison,Concentration,Exposure,Certainty in boundary,,0,1.9,One model shows period flying through predicted conc >4000 ug/m3 for a significant period of time,Comparison,Concentration,Exposure,,,0,3.5,Predicted time through 4000ug/m3 by one of the models potentially too high for safety,Exposure,Concentration,Comparison,,,1,3.5,Time likely to be near high concentrations likely to be very short,Concentration,Exposure,,,,Uncertainty levels predicted concentrations for dispersion pattern and source term,Uncertainty info,Model input,,,,6.7,6.4,3.4,2.6,2.7,5.7,,,"Satellite info is more evidence-based. Source term usually unknown for modelling work, plus inherent variation in plume behavior. ",Unknown provinence Source Data,Unknown provinence Source Data,Observation accuracy,Forecast Error,,3,3,,,,3,More evidence based,Observational accuracy,,,,Variability due to source term. Some idea of potential uncertainty in the predictions,Source data variability,Uncertainty,,,"Does include ""warning"" about source term. Plume unlikely to be this narrow near source. So more area of ""low"" concs to be shown. Level of uncertainty in the predictions.",Uncertainty,Higher resolution,,,Effect of elapsed time on validity of graphic produced,Time series,,,,1,3,2,4,,,Concentration likely to have most significant effect on a/c will depend on source term and then dispersion,Affects decision the most,,,,,Built environment,Senior consultant on air pollution,Research,18,55,Male,
133,0,7.3,0,3.3,0,0.2,1,9.8,My lack of information,Lack of information,,,,,0,0.5,1,7.7,1,9,1,9.6,Not spending prolonged exposure to >4000 ug/m3,Exposure,,,,,0,5.6,1,2.8,1,8.1,1,8.9,Moving over the 4000 ug/m3 levels (would like to know how fast/in what direction the ash cloud is moving in) and how good is the model? What errors?,Proximity,Lack of information,Uncertainty,Past Performance,,Lack of uncertainty information,4,Same as previous page. But I would like to know how fast this is changing. Is a split between the two red zones likely to stay?,Gap,Need more information,Exposure,,,,4,"I think this will be safe. However, it is possible short passes through the red zone would be okay -> would need more information",Need more information,Exposure,,,,,3.9,"Not in areas that will encounter 5000 ug/m3. Probably not in areas labeled 4000 ug/m3 as this is the max approved level and the scale is presumably rounded. Otherwise, reasoning same as in prev maps.",Concentration,Need more information,Exposure,,,,4.4,Same as prev page.,Concentration,Need more information,Exposure,,,,,,1,8.6,Doesn't go into red in either map (and both models agree),Comparison,Concentration,Certainty in boundary,,,0,7.9,"That there was a valid model (one of two) (may change mind if only one of 20ó). Indicating significant distance above 4000 ug/m3 (if it had just skimmed the red in one map and entirely missed it in the other, I may have chosen differently).",Comparison,Concentration,,,,0,5.8,See prev page,Comparison,Concentration,,,,1,9.8,See prev page,Comparison,Concentration,Certainty in boundary,,,General agreement from past experience of conservatism/non conservatism maybe a better feel for peak alues. But probably this would not change things.,Past performance of models,,,,,0,2.3,1.2,,,,,,"I do not have the previous experience to pass judgment on these products. If I had to, I would consult colleagues/literature first",,,,Lack of past experience,,,,,,,,,,,,,In part A I found the following to be missing from the data: kowledge of boundaries (is 4000 ug/m3 an upper/lower level or does it mean 3500-4500 etc.?). Info on direction/rate of travel. Info on accuracy of measurements/model output.,Explanation of graphic,Time series,Past performance,,In part A I found the following to be missing from the data: kowledge of boundaries (is 4000 ug/m3 an upper/lower level or does it mean 3500-4500 etc.?). Info on direction/rate of travel. Info on accuracy of measurements/model output.,Explanation of graphic,Time series,Past performance,,In part A I found the following to be missing from the data: kowledge of boundaries (is 4000 ug/m3 an upper/lower level or does it mean 3500-4500 etc.?). Info on direction/rate of travel. Info on accuracy of measurements/model output.,Explanation of graphic,Time series,Past performance,,,,,,,,All seem useful. Any attempt to quantify this would have helped. As would ->understanding of uncertainty and limits on engine -> is the approved ash limit for the entire flight duration or peak?,All important,Need engine info,,,,Academic/Materials Science Researcher,Academic fellow,Research,2.5,33,Female,I think this survey might be intended for someone who might look at VA/its effects rather than accellerated hot corosion from other species (in a volcanic plume or elsewhere)
134,0,2.6,0,2.4,0,0.5,0,0.6,Less confident. Less information available about density of cloud,Lack of information,,,,,0,5.5,0,5.6,0,1.8,0,1.8,Assumption-ash cloud likely to move east-assumes westerly prevailing wind. Therefore densest concn likely to move across all paths. Assumption-dispersion of ash will not take place so concn remains greater than 4000,Assumption,,,,,0,4.7,0,4.8,0,1.8,0,1.8,Assumptions listed I previous page. 1. Ash cloud likely to move east assuming westerly wind. 2. Ash cloud won't disperse at a rate to <4000 ug/m3,Assumption,Proximity,,,,,1.7,Assumes cloud moving east. Dense part of cloud at easterly edge so leaving less no fly zone on easterly edge,Assumption,Concentration,Gradient,,,,1.6,The densest (most dense) parts of cloud seems to be more concentrated-and less dense surroundings-there is a wide swath of grey blue before dense-so letting flight path closer to cloud assumes westerly prevailing wind,Concentration,Gradient,Assumption,,,,1.8,As over-this is just a fancier image,Concentration,Gradient,Assumption,,,,2.7,A wider area of lower concentrated ash on eastern edge so allow flight path closer to edge of cloud compared to previous example. Assumes cloud moving east (prevailing westerly),Gradient,Assumption,Concentration,,,,,,0,3.9,More confident as model showing similar ash concentrations,Concentration,Comparison,,,,0,4.2,A bit more confident as both models show >4000 ug/m3 concn on or close to flight path,Comparison,Concentration,Fuzziness in boundary,,,0,2.1,"Less confident as models show very different concn on flight path. Left moedl high, right model low",Comparison,Concentration,,,,0,1.9,Less confident as model showing different levels of ash concn,Comparison,Concentration,Fuzziness from comparison,,,"How many model runs? How many of each model run indicated what volcanic ash cloud-ensembles with probability. The impact of my decision how many flights this affects, passenger numbers, likely response of passengers-probabily negative? Likely possible consequences-damage to engines-what cost? More up to date information on how/where cloud of ash moving and how quickly dispersing. If this were possible!",Uncertainty info,Impact on Airline Industry,Engine information,Time series,Wind information,0,0,0,5.3,6.5,7.1,,,"VAG looks a bit ""noddy"" has lines which suggest certainty where I don't think there is. MAC-shows gradient in ash. SAR-less distinct-na",Ambiguity of uncertainty,Ash concentration information present,Too much detail,,,2,2,,,,2,,,,,,Probability of different model outputs. Historical situation under prevailing conditions. Prevailing weather: Where has cloud moved to from earlier episode,Meteorological information,Time series,Probability,Past observations,As above,Meteorological information,Time series,Probability,Past observations,As above. More distinct graphics,Meteorological information,Time series,Probability,Past observations,1,1,2,3,,,,,,,,,Research funder,Knowledge and innovation manager,Research,6,42,Female,
135,0,5.2,0,4.1,0,2.9,1,1.2,"No idea of ""how much ash"" and gradient of where we transit from low to high contamination areas",Lack of information,,,,,0,6.5,0,4.5,1,4.5,,4.7,"Based on model forecasts with associated uncertainties, particularly around edge of plume",Uncertainty,Proximity,,,,0,6.3,0,3.4,1,3.6,1,3.6,Uncertainty-especially an issue arround the edge of the plume,Uncertainty,Proximity,,,,,1.4,Use the contours given based on assumptions detailed above,Concentration,,,,,,1.8,"There is no such thing (in 2016) as a no fly zone. I'd recommend regulator SRA processes be introduced at 200 ug/m3. If pushed, I would explain that red area is region of highest contamination levels, but that difference between 2000 and 4000 is pretty small too!",Assumption,Concentration,,,,,3.2,More confidence (slightly) in obs derived fields but aware that concentrations can't be derived from satellite-derived products,Assumption,,,,,,3.2,Slightly more confidence is obs derived contours but aware that concentratoins cannot be derived from satellite derived products,Concentration,Assumption,,,,,,,1,5.7,"As previous answers, i.e exit strategy if necessary would be swift and safety impacts likely to be negligible",Concentration,Assumption,Exposure,,,1,3.2,Knowing that I there is an encounter impacts even at 4000 ug/m3 are likely to be minimal and exit from edge of plume will be swift,Concentration,Assumption,Exposure,,,0,1.8,Would recommend a slightly more northerly track (why not!!?) to reduce risk of encounter with higher areas of ash contamination,Concentration,Assumption,Diversion,,,1,6.2,"Know that 4000 ug/m3 is unlikely to pose safety issue and even if VA encountered, exit from ash plume will be swift",Concentration,Assumption,Exposure,,,Replacement of 4000 ug/m3 threshold with 1000 ug/m3 threshold! ,Change of threshold,,,,,9.8,9.8,9.8,6.1,6.2,7,6,Ground based lidar,Current VAG is too conservative with global approaches (9 VAACS) still not harmonized. And enshrined in best practice. Ash concentration difficult to produce consistently and then to verify against real data. Satpix-real data but subject to contamination from other atmostpheric parameters e.g. cloud and dust. LIDAR standardaized quantitative retrievals still to be developed,Too conservative,"Model inaccuracy, Lack of verification",Observation inaccuracy,,,3,3,,,,3,Real data-biggest issue is that it's only valid at T+0! A product that produces ash mass column loading would be the way to go -> consistent and verifiable,Observational accuracy,Column Loading,,,Understanding of the impact associated with crossing the VAG threshold line,Explanation of graphic,,,,Ditch the 4000 ug/m3 line and replace with 10 ug/m3 or even better to go to an ash mass column based product as proxy for ash concentrations,Observations,Different thresholds,,,More accurate and globally available ash mass column loading data,Better source data,,,,4,4,4,3,,,Understanding in uncertainty of all of the above all similar importance,All important,,,,,MET,Head of Natural Hazards,Research,6,48,Male,"Nice exercise, highly relevant for post Eyja/Grimsvotn in 2010/11. Less relevant now that Safety Risk Assessment policy has been brought in and that more is now known about engine damage susceptibility at ""lower"" concentrations"
136,1,2.2,1,4.7,1,4.8,1,4.8,If this is all we have then flight is okay based on forecast. Action will be taken if obs support it. Center of a plume is more likely to have higher level of ash but no info here.,Proximity,Lack of information,Assumption,,,0,4.8,1,4.8,1,4.8,1,4.8,Some conf of answers to first question. Forecasts can be wrong. Diversion is easy so why not avoid areas of high risk,Proximity,Uncertainty,,,,0,4.8,0,4.8,1,4.7,1,4.6,Flying is now possible in areas of forecast ash. The pilot can take action if any encounter occurs. I have not approved A or B as the impact of avoiding the forecast is very little,Proximity,,,,,,1.7,Lack of area in center of plume cannot realistic be assumed to have lower concentration,Gap,Assumption,,,,,1.9,Would need to know if observations support or not the forecast. These could be qualitative or quantitative. No fly is not really a recognized term,Need more information,,,,,,3.7,Timing etc. mean not sensible to differentiate middle area uncertainty in satellite data. Looks like cloud (precipitation) is across plume that oculd affect satellite data,Assumption,Gap,Uncertainty,,,,3.5,Same as before,Assumption,Gap,Uncertainty,,,,,,1,2.9,Same as before,Diversion,Need more information,,,,1,2.2,Model data alone provides guidance only. Would require operator to take suitable action if/when actual encounter would use observations. If impact of different route small then would always go for that in preference,Diversion,Need more information,,,,1,2.3,Same as before less confidence as difference between models goes from lower risk to higher risk,Diversion,Need more information,Comparison,Fuzziness from Comparison,,1,3.1,Same as before including taking different route being first option,Diversion,Need more information,,,,"Observations. Options for different routes i.e. are they possible. Explanation guidance on forecast both in terms of recent verification, forecast confidence (even just from meteorology)",Observations,Diversion information,Past performance of models,Uncertainty info,,10,10,10,6.9,7.5,8,5.2,"LIDAR; Pireps, etc.",All models/obs have uncertainty. Concentration gradients allow better appreciation of impact of errors than simple VAC. Satellite measure column loading and variation of a factor of 2 to 4 possible,Model inaccuracy,"Model inaccuracy, Ash concentration information present",Observation inaccuracy,,,,,,,Modelled column loading,,For what purpose: forecasting/planning or now? I think in terms of forecasts! Column loading more of a consistent product,Column Loading,,,,"Multiple levels-gradients, representation of uncertainty-need to be clear what it includes!, joint model and obs graphics to help understand like for like",Ash concentration,Uncertainty,Observational information,,"Multiple levels-gradients, representation of uncertainty-need to be clear what it includes!, joint model and obs graphics to help understand like for like",Higher resolution,Uncertainty,Observations,Explanation of graphic,Measure of accuracy. Transparancy on assumption and modelled data used,Accuracy information,Explanation of source data,Explanation of graphic,,3,1,4,2,,,1 and 2 are the same thing,,,,,,Weather service,Head of dispersion modelling,Research,3,44,Male,
137,0,9.8,0,8.5,0,6,0,4.9,The forecast of the level of ash plus knowledge of the uncertainty in this map plus precaution principle,Proximity,Uncertainty,Assumption,,,0,9.5,0,8.6,0,6.5,0,5.5,"due to the intrensic uncertainties in the forecast, this map helps understanding better the situation, but it will not change the decision neither the level of confidence",Uncertainty,,,,,0,9.4,0,8.5,0,6.8,0,5.8,"Same as before. This is a useful information, but the level of uncertainty envelope the information provided, thus the decision will not change",Uncertainty,,,,,,1.5,Same as before. Uncertainty in modelling and forecasting envelope (superceed) information and precautions,Need more information,Assumption,Uncertainty,,,,1.3,Same as before,Need more information,Assumption,Uncertainty,,,,1.4,Same as before,Need more information,Assumption,Uncertainty,,,,1,All important information missed here is the meteorological situation in which direction the ash cloud will move? We must assume that it could move everywhere. Model analysis are also very uncertain. This has been taken into account,Need more information,Assumption,Uncertainty,,,,,,0,1.3,Same as before,Uncertainty,Comparison,,,,0,1.9,Same as before,Uncertainty,Comparison,,,,0,1.2,"In both case, considering the uncertainties I see an unacceptable level of risk on both flight path",Uncertainty,Comparison,,,,0,0.7,Same as before,Uncertainty,Comparison,,,,Information on meteorological situation. Information on the actual uncertainty of the model output and forecast,Uncertainty info,Meteorological information,,,,5.6,5.8,4.6,2.4,2.5,2.8,,,"Being very used to look at meteorological model, I suppose a similar degree of uncertainty in ash models",,,,Model inaccuracy,,,,,,,,All similar,All similar,,,,"Meteorology (wind/pressure), uncertainty",Meteorological information,Uncertainty,,,same as above,Meteorological information,Uncertainty,,,same as above,Meteorological information,Uncertainty,,,,1,,2,,,"If we use a precaution principle, concentration and altitude will not affect the final decision",Affects decision the most,Pragmatic Approach,,,,energy,natural hazard and environment research manager,Research,10,40,Male,"Depending on the precautions a given industry would take (aversion to risk) more or less time information will be required. Supposing here that we want to be very risk averse (human lives in danger) the information in figure 1 and uncertainty bounds and met conditions would be enough. That doesn't mean that the other figures are not useful, but in this context they will not change the decision"
138,0,10,0,3.6,1,0.9,1,2.6,Proximity to predicted ash cloud location and whether the flight plan goes through the center or edge of forecast plume,Proximity,,,,,0,10,0,8.6,1,0.2,1,1.4,Distance from predicted contours. Not confidence is allowed flightpaths due to potential errors in concentration and plume location,Proximity,Uncertainty,,,,0,10,0,9.3,1,0.4,1,2.4,"Ash concentrations of satellite data. Whilst (3) is within permitted levels, errors and uncertainties of a factor of 2 could  lead to this being above the 4000 ug/m3 limit",Proximity,Uncertainty,,,,,1.3,Buffer zone around the grey contour to account for spatial errors in the plume location,Margin,Uncertainty,Concentration,,,,1.5,Slightly smaller buffer zone here influenced by the greater distance to the red zone,Concentration,Margin,Gradient,,,,1.4,Buffer zone around ash plume-here edges of the plume appear more coherent/strong gradients in ash concentration so I would tend to go for a zone based on the ash cloud location rather than concentrations,Margin,Gradient,Concentration,,,,0.9,Buffer zone around the 2000 ug/m3 to allow for spatial errors,Margin,Uncertainty,Concentration,,,,,,0,0.3,One forecast has the flight path passing very close to the red zone,Comparison,Concentration,Fuzziness in boundary,,,0,7.4,One forecast has the flight path passing through a central (red zone) part of the plume,Comparison,Concentration,,,,0,3,"One forecast flies through the red zone. Perhaps some extra information, (e.g. later forecast) may give more confidence in the other plot to reconsider this decision",Comparison,Concentration,Need more information,,,0,3.2,"Again, one flight path is extremely close to the red zone-well within potential positional errors",Comparison,Concentration,Fuzziness in boundary,,,Observatoins (e.g. from aircraft) supporting the forecasts. Some information on lead time of forecasts. Information on the level of uncertainty in the driving meteorology e.g. in the weather forecast and in the model inputs e.g. whether the assumed model source was over and under done for this eruption,Observations,Uncertainty info,Model input,Meteorological information,,7.8,9.1,4.5,10,3.5,6.6,,,VAGs give ash location (and do not venture into concentrations) so likely to be more correct (or perhaps overdone) Large uncertainties in source cause large uncertainties in ash concentrations. Satellite are real observations (although with errors in the retrieval process),Accuracy in simplicity,Unknown provinence Source Data,"Observational accuracy, observational inaccuracy",,,1,1,,,,1,Feels safer to predict ash location (and it is usually modified due to any observations),Just need location information (certainty in simplicity),,,,Many forecasts from different times/forecasts for variations in source details (e.g. eruption height) within their levels of uncertainty),Time series,More model outputs,Uncertainty,,Forecasts from other source terms (e.g. from an inversions). Forecasts from different times (as above),Time series,More model outputs,,,Estimated uncertainties and identifying regions which may be particularly uncertain (e.g. due to presence of cloud),Uncertainty,,,,3,1,4,2,,,Position seems to me to be the most inmportant piece of information. The others are a bit random in their ordering!,Affects decision the most,,,,,Met office research,Atmospheric dispersion modeller,Research,17,43,Female,
139,0,7.5,1,3,1,7.8,1,7.5,A flies through center of forecast ash cloud-likely to account for uncertainties in position,Proximity,Uncertainty,,,,0,7.3,0,5.3,1,5.3,1,6.5,"Recent forecast time, high forecast ash concentrations in proximity to all paths",Proximity,,,,,0,8,0,7,1,5.8,1,7,Satellite image implies no cloud at east edge of ash cloud which could be obscuring the ash. Concentration gradients are fairly uniform,Proximity,,,,,,4.5,"Again provided a buffer zone, particularly in between the two high conc zones",Margin,Gap,Concentration,,,,4.3,As before,Margin,Gap,Concentration,,,,4,"Slightly large than last scenario because the 2000 ug/m3 ""buffer zone"" is narrower",Concentration,Gradient,,,,,4.8,Around ~2000 ug/m2 as a buffer zone. Included area south of Iceland as high conc. Ash near to vent can often be obscured in satellite imagery,Concentration,Margin,Assumption,,,,,,0,4,Path very close to high conc. Ash in model 2. Small error in position could lead to risk of entering that zone,Concentration,Comparison,Fuzziness in boundary,,,0,5.8,As before,Comparison,Concentration,,,,0,5.8,50% of model runs show flight path entering no fly zone,Comparison,Concentration,,,,1,5.3,"As in previous, model 2 shows flight path v. close to high conc. Zone but model 1 predicts that region to be much further west. ",Comparison,Concentration,Fuzziness in boundary,,,Conjunction with satellite imagery and more model runs-different models or NWP ensemble for example,Observations,More model outputs,,,,6,9.5,9.3,7.5,5,5,,,VAAC advisories encompass regions larger than the modelled ash clouds to account for errors. Model runs are only as trustworthy as their inputs. Retrievals are estimates of ash properites- can have high uncertainty,Built in uncertainty,Unknown provinence Source Data,"Observation inaccuracy, model inaccuracy",,,,,,,,,In terms of what? Not sure I can answer!,,,,,Height estimates,Altitude information,,,,estimate of positional error e.g. lowest vs. highest likely cases,Uncertainty,More model outputs,,,Error (uncertainty of solution/solution cost). Different refractive indices?,Uncertainty,Explanation of graphic,,,1,1,1,1,,,All very useful!,All important,,,,,Academic,PhD Student,Research,3,28,Female,Difficult to rank confidence in decisions-is confidence in safety or managing economic losses?
140,0,7,0,5.5,1,4.5,1,4.3,"A and B go straight through the ash cloud therefore presume high risks of encountering high concentrations of particulates. C and D are marginal, they go through the edge of the ash cloud-but there is insufficient information to understand what concentrations of ash they are likely to encounter",Proximity,Exposure,Lack of information,Assumption,,0,10,0,5.5,1,5.5,1,7,Proximity to max conc ? 4000ug/m3,Proximity,,,,,0,10,0,5.5,1,5.5,1,7,Proximity to high concentrations of volcanic ash,Proximity,,,,,,4.3,1. Avoiding areas of high concentration. 2. Avoid trough between peaks-unsure how quickly situation changes,Concentration,Gap,Need more information,,,,5,"Avoiding areas of high concentration, leaving some room for error by straddeling the 2-4k ug/m3 region.",Concentration,Margin,Uncertainty,,,,5,1. Avoiding high concentration areas. 2. Included the acceptable area between two peaks out of caution - I am unsure how quickly the situation changes,Concentration,Gap,Need more information,,,,4.5,Midway through yellow region: gradient of concentration very high therefore do not want to be too close to areas of high concentration. Difficult to distinguish between 5k and 4k ug/m3 regions (so weary of drawing a tighter bound),Gradient,Concentration,Margin,,,,,,0,4,"Both flight paths avoid high concentratoin regions. However, the path is very close to a high concentration region and goes through a medium concentration region. One assumes there is greater uncertainty in where the peak region is. ",Comparison,Concentration,Fuzziness in boundary,Uncertainty,,0,7.5,"One forecast idicates high level of volcanic ash on fliht path.  This implies there is uncertainty in the extent of the plume, so better to be cautious",Comparison,Concentration,Fuzziness from comparison,Uncertainty,,0,6.5,"One of the forecasts suggests the flight path goes straight through a high concentration region therefore high uncertainty, so more caution required. ",Comparison,Concentration,Uncertainty,Fuzziness from Comparison,,1,2.3,Both forecasts indicate the flight path does not go through a region of high concentration. However the right hand forecast indicates that the flight path may go very close to a high concentration region. This proximity leaves me with low confidence in my decision,Comparison,Concentration,Fuzziness in boundary,,,Gradient information. Confidnece in each forecast (i.e. a weight). Ensemble of outputs (maybe of the worst case scenario of each run?),Gradient,Uncertainty info,More model outputs,,,0,2,1,2.5,4.5,4.5,,,a. It is harder to interpret what is going on: the heat maps in (b) make the situation clearer,Lack of information,Ash concentration information present,,,,2,2,,,,2,I find it easier to interpret,Clarity,,,,A better sense of the range and spread,Uncertainty,,,,More regions/ uncertainty,Higher resolution,Uncertainty,,,A better explanation of what this shows,Explanation of graphic,,,,4,3,2,1,,,"Not an expert judgement, but (5)-to an extent covers the remaineder. It seems like the uncertainty in concentration would be trump the remaining uncertainties",Affects decision the most,,,,,Maths,Mathematical consultant,Research,2.5,31,Male,