attempt weaken tropical cyclones flying aircraft silver project run hypothesis silver cause water storm freeze disrupting inner structure hurricane led atlantic hurricanes later shown hypothesis incorrect determined hurricanes contain water cloud effective additionally researchers found hurricanes undergo structural changes expected seeded hurricanes finding called successes question changes reported natural explanation experimental flight flown lack candidate storms fleet decade modification experiment officially canceled failure goal reducing hurricanes merit data storm research generated helped improve ability forecast movement intensity future hurricanes hypothesis cloud attempted witnessing artificial creation ice crystals enthusiastic proponent weather modification found dumped crushed dry ice cloud precipitation form snow resulted regard hurricanes area eyewall silver heat released promote formation new eyewall new eyewall larger old eyewall winds tropical cyclone weaker reduced pressure gradient small reduction speed hurricane winds beneficial damage potential hurricane increased square wind speed slight lowering wind speed large reduction efforts research general_electric concept cloud weaken hurricanes gathered momentum caused major december cloud caused drop legal reasons assisted military advisors large study cloud physics weather modification important goal try weaken hurricanes attempt modify hurricane collaboration air_force preparations initial skepticism government scientists attempt modify hurricane began october hurricane heading west east sea airplane flew rainbands hurricane dropped nearly pounds kilograms crushed dry ice clouds crew reported pronounced modification cloud deck seeded known hurricane changed direction landfall near savannah georgia public blamed claimed reversal caused human intervention canceled lawsuits threatened fact system taken similar path evidence showing storm begun turn began ended litigation disaster set cause hurricanes years projects united_states weather_bureau founded objectives investigate scientific validity hurricane modification methods end silver tested hurricane august deployed outside hurricane eyewall equipment test modification experiment equipment flights conclusive data acquired experiment disaster attempted september united_states navy aircraft cylinders silver dropped eyewall winds recorded weakening percent day flights time silver fall eyewall reduction observed results interpreted making experiment success hurricane led establishment joint venture united_states_navy project objective project analysis life history thunderstorms research activity supported sought expand understanding storm physics aid weather fire prevention possibly artificially controlling weather employee research inc joint leaders project team july august storm season arizona scientists selected guinea pig storms seeded chemicals effects thoroughly analyzed ground air time lapse motion picture cameras stereo cameras storm radar lightning airborne heat sensors agents inserted selected clouds temporarily increased number water cloud dry ice turns portion cloud fine snow crystals remain aloft agents facilitated study storm characteristics begins director serving capacity guidelines selecting storms seed hurricane percent chance approaching inhabited land day range aircraft fairly intense storm formed eye primary effect criteria possible targets extremely rare suitable storms formed season year began conducting experiments clouds august year experiments conducted clouds seeded controls seeded clouds changes consistent working hypothesis observed august site attempt indistinct eyewall addition mistakes silver dropped wrong places consequence happened day attempt hit targets eyewall observed fall apart replaced eyewall larger radius sustained winds fell percent results experiments encouraging inconclusive years conducted different reasons measurement observation equipment ready year flights additional experimentation non hurricane clouds director beginning sea august atlantic hurricane season decided hurricane good candidate storm immediately swung land september planned flights canceled reason press notified newspapers reported begun passed close bahamas smashed southern florida public congress thought underway blamed took months officials convince congress seeded project allowed continue second candidate stayed far sea hurricanes came close seeded hurricane faith considered likely candidate stayed range planes year flights conducted seasons inactive suitable targets seasons director near interim equipment improved primitive method hand dumping dry ice replaced rocket loaded silver gun like devices mounted wings fired silver clouds observation equipment improved additional reconnaissance data utilized modify working hypothesis new theory took towers outside eyewall account according revised theory towers heat released trigger start new convection cause new eyewall new eyewall outside original eyewall energy fall apart addition new eyewall broader old winds lower sharp pressure difference hurricane provided best opportunity test ways perfect storm threaten land passed range aircraft intense distinct eye august august thirteen planes flew storm monitor seed day fell second day fell changes consistent working hypothesis results encouraging greatly expanded research program planned conclusions need frequent close hourly intervals seasons provided suitable candidates despite flights conducted suitable storm indistinct nature effect atlantic hurricanes meeting criteria extremely rare success reached extremely difficult developments outside hindered cause hurricane modification early 1970s navy withdrew project began efforts understanding modifying tropical cyclones time project aircraft nearing end operational cost million year unknown lockheed acquired rarity atlantic hurricanes meeting safety requirements plans pacific experiment large number action required safety requirements atlantic advantage higher number potential subjects plan begin seed flying guam political issues blocked plan announced happy seeded typhoon changed course landfall shores japan declared willing difficulties caused country got half rainfall tropical cyclones similar plans operate eastern north pacific australian region collapsed failure working hypothesis multiple detected strong hurricanes including double eyes usually seen intense systems double seen post seeded storms time known times rapid changes eyewall diameter presumably successful rapid changes intensity remained controversial caused secondary natural cycle basically eyewall changes similar observed seeded hurricanes rare tropical cyclones provide powerful evidence successful conversely changes common systems throw doubt hypothesis assumptions driving data observations began accumulate working hypothesis beginning david flights hurricane hunter aircraft encountered events similar happened successfully seeded storms weak example concentric eyewall cycle david dramatic august hurricane allen passed atlantic caribbean gulf_of_mexico underwent changes diameter eye developed multiple consistent behavior expected allen seeded happening observations david allen discovered tropical cyclones little water great deal ice crystals reason tropical cyclones little water system weak prevent water falling rain freezing cloud needed water function lack water meant effect observations called basis question middle finally canceled hypothesis guiding efforts legacy sense weakening hurricanes reduce complete failure distinguish natural phenomena tropical cyclones impact human intervention millions dollars spent trying impossible end fatal flaws feasible addition primary generator funding project operational budget million usd million usd staff approximately people today employs people budget roughly million year positive results knowledge gained flights proved science resulted greater understanding tropical cyclones addition lockheed perfectly suitable gathering data tropical cyclones allowing improved monstrous storms planes today cuban president alleged attempt hurricanes
Project Stormfury