Frost fairs, sunspots and the Little Ice Age Article Accepted Version Lockwood, M., Owens, M., Hawkins, E., Jones, G. S. and Usoskin, I. (2017) Frost fairs, sunspots and the Little Ice Age. Astronomy & Geophysics, 58 (2). 2.17-2.23. ISSN 1366-8781 doi: https://doi.org/10.1093/astrogeo/atx057 Available at http://centaur.reading.ac.uk/69443/ It is advisable to refer to the publisher’s version if you intend to cite from the work. See Guidance on citing . To link to this article DOI: http://dx.doi.org/10.1093/astrogeo/atx057 Publisher: Oxford University Press All outputs in CentAUR are protected by Intellectual Property Rights law, including copyright law. Copyright and IPR is retained by the creators or other copyright holders. Terms and conditions for use of this material are defined in the End User Agreement . www.reading.ac.uk/centaur CentAUR Central Archive at the University of Reading Reading’s research outputs online THE LITTLE ICE AGE To be published in A&G, Astronomy and Geophysics, March 2017 1. The great ArBCt AaDr BA EF84 paDnted by an unknBwn artDCt. The paDntDng DC generally knBwn aC Frost fair oA tBC DBaECsF witB old LoAdoA BridgC iA tBC distaAcC whDch DC a tDtle Dth hDdden CDgnDADcance becauCe LBndBn BrDdge waC DmpBrtant Dn generatDng the cBndDtDBnC that allBwed the Dce tB becBme ADrm and thDck enBugh tB CuppBrt the AaDr. PaDntDng cBurteCy BA the Paul MellBn BllectDBn, Yale Center ABr BrDtDCh Art, New Haven, BnnectDcut). Frost ABCsD sEFspots BFd the LCttle Ice Age Mike LockwooA, MBC DweEF, in solar activity in the minds of many latitudes at the time of their deposition people. Hence it has even become were depressed. This is because it takes EA HBwkiEF, GBreCh S. JoEeF possible to build semantic arguments that more energy to evaporate the water imply there is some sort of link between molecules containing these heavier and IlyB UFoFkiE examine the links solar activity and ice ages – and evidence isotopes from the surface of the ocean between the solar Maunder minimum, for major control of climate by solar and, in addition, as the moist air the Little Ice Age and the freezing of activity is often offered in the form of the containing the evaporated water is occurrence of frost fairs on the Thames in transported polewards and cools, the the River Thames. London. This paper discusses the true water molecules containing the heavier relationships, or lack of them, between isotopes are more easily lost by here spin doctors, these different events. precipitation. Both processes mean that politicians and newspaper less deuterium and 18O reaches the polar W editors understand well that IDE AFEs regions if global temperatures are lower. a name alters how Before discussing the “Little Ice Age” we This “fractionation” effect can be something is perceived, scientists know should be clear what a proper ice age is. calibrated and so a record of temperatures that a name does not change the reality Global temperatures can be inferred from back to the distant past can be generated one iota. By virtue of the name awarded polar ice cores using the isotopic from measurements of the abundance of to it, the “Little Ice Age” has been 2 18 composition of the water molecules. In H and/or O in deep cores into ancient associated with full ice ages. The name particular, the amounts of deuterium (2H) polar ice sheets. Figure 2 shows Little Ice Age has also become almost and of the 18O isotope present in the ice temperatures deduced from ice cores synonymous with the Maunder minimum are lower if temperatures at lower taken at the Vostok station in Antarctica ABABABCABCCC THTHE LLITTLITTLETTLEE ICICECE AGAGEE thathat are dedeepp enonoughgh to allolloww uss tto seseee ththe varariatiotionn ooverver the papast 4420,20,00000 yearsye rs (frofrom PetiPetit et al.l., 191999)9). ThThee tempt mperaeraturure iss sshowown aas ththee diffed fferenence relativeive to preresenent daday vvalueluess (i(in ootheher wordsw rds as a temempereratuturee ““anonomaaly”y”, ∆T ). TheTh icice cororess rever veall tthatat glolobalal tememperperatuturee iis chaharacacterisriseded byy rapapidd rrisesses, followfo loweded by graraduaual dedeclinlines.es. 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NNoteote alsalso eratratureres in sosouthethernrn Engnglanland avera erageged rrecoconstrstructctionons ememplploysys mumultipltiplele ththat thee LLIAIA persispersists foforr 5005 0 yeaearss ata abobout −8°C wwithth mininimimumm andnd maximm ximumum tetempmperaeratureure proxipr xies,s, inclncludidingg dataata frofromm mmost,st, comcompaparedred to thehe 20,00020 00 yeyearsrs of thehe seaeasononall vvaluluess ofo −30°C aandd +8°C bborerehololes,s, coraoralsls aandnd scleroscl rospopongeges,, iice lalastt icicee aage.e. SeverSe erall ccaususess oof ththe LIAL A (AtkAtkinsinsonn ett aal., 198987). 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ThThee sstartart and enden agege startedsta ted to comeme to aan enend (Barartonton et ((recoecorderded ffreezeeze/te/thawaw dates,da es, haharvevest dadateses off thee LIAIA dedepenendd sstronronglygly on the al.,l., 200003).3). yyieldeldss aandd ddateates,s, eetc.)c.) (see(se rrevieview of tetempeperatraturere proroxyy usesed to dederiveive themth m tetechchniquiqueses byy Jononess andand Maannn, 2004)20 4). anand oon ggeogograpaphicic regegionon. EEvididencec frfromm ThThE LittlittlEE IDEIDE AFAFE TThee cololoururs givegi e tthee prorobababilitylity denside sity mmoununtainain glaciegl ciers sugguggestest incincreareaseded Comompapareded to thehe chahangegess in theth propp operr icice ffuncnctionion (p(pdf)f) inn eeachch year,ye r, thathat allowall w foror gllaciaciatiotion in a nnumumberer of wididelyely-spreadsp ead ageges,, thethe sso-ccallelled ““littlittle icice age”age” (LILIA)) is bbothth the cocompputedted uncerun ertainaintieties in eacach reregioions aarouound thehe 12tth centuce tury AADD: thethesese a veveryry shohort-lliveded anand vveryry punypu y cclimlimateate rrecoconstrstructctionon andnd theth differdi ferencncess inincludlude AAlaslaska,a, NeNew ZZealealandnd, AAmeericaica andnd socialsocial perertururbatiation.n. ThThe termte m waas bbetwtweenen ththe reconre onstrutructictionsns. TThee llargrger anand PPatatagononia.a.