高考英语考前突破阅读理解能力科普类人火山喷发与寒冷天气的关系素材

1火山喷发与寒冷天气的关系MedievalchronicleshavegivenaninternationalgroupofresearchersaglimpseintothepasttoassesshowhistoricalvolcaniceruptionsaffectedtheweatherinIrelandupto1500yearsago.Bycriticallyassessingover40,000writtenentriesintheIrishAnnalsandcomparingthemwithmeasurementstakenfromicecores,theresearcherssuccessfullylinkedtheclimaticaftermathofvolcaniceruptionstoextremecoldweathereventsinIrelandovera1200-yearperiodfrom431to1649.Theirstudy,whichhasbeenpublishedtoday,6June,inIOPPublishing'sjournalEnvironmentalResearchLetters,showedthatoverthistimescaleupto48explosivevolcaniceruptionscouldbeidentifiedintheGreenlandIceSheetProject(GISP2)ice-core,whichrecordsthedeposition（沉积物）ofvolcanicsulfateinannuallayersofice.Ofthese48volcanicevents,38wereassociated,closelyintime,with37extremecoldevents,whichwereidentifiedbysystematicallyexaminingwrittenentriesintheIrishAnnalsandpickingoutdirectlyobservedmeteorologicalphenomenaandconditions,suchasheavysnowfallandfrost,prolongedicecoveringlakesandrivers,andcontemporarydescriptionsofabnormallycoldweather.Leadauthorofthestudy,DrFrancisLudlow,fromtheHarvardUniversityCenterfortheEnvironmentandDepartmentofHistory,said:It'sclearthatthescribesoftheIrishAnnalswerediligentreportersofseverecoldweather,mostprobablybecauseofthenegativeimpactsthishadonsocietyandthebiosphere.Ourmajorresultisthatexplosivevolcaniceruptionsarestrongly,andpersistently,implicatedintheoccurrenceofcoldweathereventsoverthislongtimescaleinIreland.Intheirseverity,theseeventsarequiterareforthecountry'smildmaritimeclimate.Throughtheinjectionofsulphurdioxidegasintothestratosphere,volcaniceruptionscanplayasignificantroleintheregulationoftheEarth'sclimate.Sulphurdioxidegasisconvertedintosulphate（硫酸盐）aerosolparticlesaftereruptionswhichreflectincomingsunlightandresultinanoveralltemporarycoolingoftheEarth'ssurface.Whilsttheglobaleffectsofrecenteruptionsarequitewell-known,suchastheMountPinatuboeruptionalmost22yearsago(15June1991),lessisknownabouttheireffectsonclimatebeforethebeginningofinstrumentalweatherrecording,ortheireffectsonregionalscales;theIrishAnnalsprovidedanopportunitytoexplorebothoftheseissues.2TheIrishAnnalscontainoveronemillionwrittenwordsandaround40,000distinctwrittenentries,detailingmajorhistoricaleventsonanannualbasis,andprovidingbothsystematicandsustainedreportingofmeteorologicalextremes.