Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere.
Xu-Cheng HeMario SimonSiddharth IyerHong-Bin XieBirte RörupJiali ShenHenning FinkenzellerDominik StolzenburgRongjie ZhangAndrea BaccariniYee Jun ThamMingyi WangStavros AmanatidisAna A PiedehierroAntonio AmorimRima BaalbakiZoé BrasseurLucía CaudilloBiwu ChuLubna DadaJonathan DuplissyImad El HaddadRichard C FlaganManuel GranzinArmin HanselMartin HeinritziVictoria HofbauerTuija JokinenDeniz KemppainenWeimeng KongJordan E KrechmerAndreas KürtenHoussni LamkaddamBrandon LopezFangfang MaNaser G A MahfouzVladimir MakhmutovHanna E ManninenGuillaume MarieRuby MartenDario MassabòRoy L MauldinBernhard MentlerAntti OnnelaTuukka PetäjäJoschka PfeiferMaxim PhilippovAnanth RanjithkumarMatti P RissanenSiegfried SchobesbergerWiebke ScholzBenjamin C SchulzeMihnea SurduRoseline C ThakurAntónio ToméAndrea C WagnerDongyu S WangYonghong WangStefan K WeberAndré WeltiPaul M WinklerMarcel Zauner-WieczorekUrs BaltenspergerJoachim CurtiusTheo KurténDouglas R WorsnopRainer VolkamerKatrianne LehtipaloJasper KirkbyNeil M DonahueMikko SipiläMarkku KulmalaPublished in: Science (New York, N.Y.) (2023)
The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H 2 SO 4 ), stabilized by ammonia (NH 3 ). However, in marine and polar regions, NH 3 is generally low, and H 2 SO 4 is frequently found together with iodine oxoacids [HIO x , i.e., iodic acid (HIO 3 ) and iodous acid (HIO 2 )]. In experiments performed with the CERN CLOUD (Cosmics Leaving OUtdoor Droplets) chamber, we investigated the interplay of H 2 SO 4 and HIO x during atmospheric particle nucleation. We found that HIO x greatly enhances H 2 SO 4 (-NH 3 ) nucleation through two different interactions. First, HIO 3 strongly binds with H 2 SO 4 in charged clusters so they drive particle nucleation synergistically. Second, HIO 2 substitutes for NH 3 , forming strongly bound H 2 SO 4 -HIO 2 acid-base pairs in molecular clusters. Global observations imply that HIO x is enhancing H 2 SO 4 (-NH 3 ) nucleation rates 10- to 10,000-fold in marine and polar regions.