ComparisonCi off earlyl upperupper‐airi observationsbti iniin ChinaChiChina andandd KoreaKKorea withwithith theththe TwentiethTtithTwentieth CenturyCtCentury andandd ERA‐20C0 reanalysesea al yses Alexander Stickler1,212, Richard Wartenburger1,2*1,212*, and Stefan Brönnimann1,212 1OhOeschger CentreC forf ClimateCli ChangeCh Research,RhResearch Bern,BBern SwitzerlandSiSwitzerland l d 2IInstInst. off Geography,GhGeography Univ.UiUniv Bern,BBern SwitzerlandSi l d *now at Inst.IInst off AtmosphericAhi andd ClimateCli Science,ScienceSi ETHETH ZürichZürichZü i h ([email protected], stickler@giub unibe ch Phone:Phone: +41+41 3131 631631 8888 43)43)

11. IntroductionIdi 33. Reanalyses Fig. 2: Photo‐ IIn ththe fkframework off theth EU FP7 pjprojectjt ERA‐ graphyh off SSven 20CR (Compo et alal., 2011) and ERA‐20C (Poli et al.,al 2013) are Hedin (1865‐ datasets totally independent from any upper‐air observations CLIM, hithhitherto t unavailableil bl earlyly upperpp ‐airi 1930 1935 1952), leader off that are based on the assimilation of surface observations only observationsobsebti at o s fromf o ChinaChiCa andadd KoreaKoeahhaveae beebbeen several expedi‐ didigitised iti d. TheseTh encompass ttwo kitkite recordsd tions to central (synoptic pressure (FigFig. 3)), hurricane tracks,tracks plus marine winds for ffrom ththe SiSino‐SdihSwedish EExpedition diti 1931/32 iin AiAsia bbetween ERA‐20C) into a numerical weather modelmodel, using monthly sea ththe bdborder regioni off ChinaChi andd MongoliaMli 1890 and 1935, surface temperature and sea ice as boundary conditions.conditions Here,Here we (EdEdsen‐GlGol, IkIkengüng ü , totall 217 profiles;fil amongst them use the 20CR ensemble mean and the ERA‐20C “bestbest guess”guess runrun, a ththe SiSino‐SSwe‐ 1942 1945 single model run.run HdHaude, 1940),1940) threeh pilotil bllballoon, one kikite dish Scientific andd one aircraftif recordd ffrom theh earlyl 19301930s Expedition to FiFig. 33: SynopticSti pressure datadt assimilatediiltd intoit 20CR andd ERA‐20C20C: availableil bl synopticti Theh reanalysisli datad willill bbe extractedd at theh closestl reanalysisli gridid ffrom ChinaChi (ji(, ,iji Xi’an,Xii’ an, ca. 2,3002 300 the North‐Western Provinces of pressure stations of the International Surface Pressure Data Bank (ISPD V2) for the pointi ini theh horizontalhi l , linearlyli l interpolatedild ini timei usingi theh ffour‐ 1927‐35 (https://www.dhm.de/lemo/ yearsyea s 1930,930, 1935,935, 19429 adand 1945.95 A fefew addadditional t o a statstations o s aeare aaabeavailable duduring g 1930930‐ profiles;fl Nationall Researchh Institute off bibiografiegf fi /sven‐hdihedin). 35 in Eurasia in ISPD V3V3.2.6, 2 6 used in ERA‐20C20C, particularly in Cyprus,Cyprus Irak, Manila and timesi dailydil data,d andd finallyfi ll interpolatedild verticallyill to theh geometrici MeteorologyMeteorology,l 1930‐35)) andd seven radiosondedd PalauPalau. The total number of available stations in ISPD V2 (V3) increases from 576 (607) in hihheight lllevels off theh observationsbi usingi theh reanalysisli geopotentialil records ((total caca. 44,300 300 profiles)) registered by 1932932 to 1,463, 63 ((1,488)(, 88) ) iin 1935,93 , 1,579, 9 (8)(1,587)(, ) iin 1942,92, andd 2,14828, (2,155)(2(, ) ini 1945.9 Note theh hihheight ifinformation i . the Japanese military during WWII in Korea generally small number of observations in China before 1945.1945 (Incheon) and in NE China ((Changchun, Hailar, Taonan, DalianDalian, Jinzhou; Central ERA‐CLIM ID Station Altitude [m[ asl]] Median heightg [[m asl]] Maximum heightg [[m asl]] Meteorological ObservatoryObservatory, 1950abc) (Figs(Figs. 22. UUpperpp ‐airi ddata 4786 DliDalian R 72 99,072 072 1616,072 072 12)1,2). To our knowledgeknowledge, only Hong Kong and 4787 P/RB 72 11,622 622 1313,122 122 ThThe 19301930s expeditionp diti andd 4788 Incheon R 5454.1 1 1111,054 054 1515,054 054 have earlier upper‐air data in China 4790 Changchun R 215215.3 3 1414,215 215 1818,215 215 (back to 1921 and 19271927, respectively)respectively). ChiChinese stationtti recordsd containti wind,id, pressurep andd 4791 Hailar R 619 12,619, 18,619, The pressurepressure, temperature,temperature humidity and 4792 Jinzhouh R 51.9 15,052 18,052 tttemperaturep dtdata (FiFigs.g 4 andd 4793 TTaonan R 152152.2 2 1313,152 152 1818,152 152 wind observations will be compared to two 5)). FFrom ththe JJapanesep WWII totally independent datasets: the Twentieth 4854 Nanking P 83 44,500 500 2222,500 500 recordsd , 6 containti pressure,p, 4855 Nanking A 83 22,500 500 55,700 700 Century Reanalysis (20CR) and the recent temperattemperaturep re and relativerelati e 4856 Peiping P 64 4,000 12,500 ERA‐20C reanalysis. hhumidity midity dtdata,, 2 windind dtdata,, 4857 Peipingpg K 64 2,000, 4,114, and 2 both groupsgpro ps of 4858 SiSian P 400 44,500 500 99,000 000 parametersparameters.p All the data are 5407 EdEdsen‐GlGol K 920 11,420 420 44,160 160 giveng on geometricalg altitude 5408 Ikengüng K 11,470 470 11,930 930 44,480 480 levelslevels. The data have been TblTable 1:1 MedianMdi andd maximumi heightshihtg reachedhd ini theth upperpp ‐airi records.d RR: radiosonde,di d P: pilot balloon,balloon RB: registering balloon,balloon K: kite.kite imaged,imagedg, digitisedg and Fig. 4: Left: Example of pilot balloon observations for February and March 1930 from SiSino‐SdihSwedish EdiiExpeditionp NankingNanking. Middle:Middle Example of aeroplane observations ofof pressure,pressure temperature,temperature relativerelative 1931/32 • subjectedj to a raw qualityqy humidity and wind for 1933 from Nanking. Right: ExampleExample ofof pressure,pressure, temperature,temperature, Earlyy Chinese stations control in the framework of relative humidity and wind observations for 1933 from Peiping.Peiping Source: Bulletin of the 1930‐35 • the Europeanp pjproject ERA‐ Upper Air Current Observations (National Research Institute of Meteorology, 1930‐35). RfReferences Japanese WWII stations CLIM (Stickler( et al.,al , 2014ab).2014ab)) BöBrönnimann i S & SticklerSikl A 20132013. MlMeteorol. ZZ. 222, DOIDOI: 1010.1127/0941 1127/0941‐948/2013/0458. 1942‐45 • Compo GP et al. 2011. Q. J. R. Meteorol. Soc. 137: 1‐28. The maximum and median Central Meteorological Observatory 1950a1950a. Aerological data of Dairen (radiosonde)), Sept.‐DecDec. 1944, JJan.‐MhMarch 19451945, CtlCentral MtMeteorological l i l ObObservatory, t TkTokyo. heights above sea level (asl) Centraleta Meteorologicaleteo o og ca ObseObservatory ato y 1950b.950b Aerologicaleoogca data of Korea,oea, 19429 ‐44,, Centraleta reached by the various Meteorological ObservatoryObservatory, TokyoTokyo. CtlCentral MtMeteorological l i l ObObservatory t 19501950c. AlilAerological dtdata off MhiManchuria (radiosonde),di d ) 1942‐4444, measurements at the different Central Meteorologicalg Observatory,y, Tokyo.y upper‐air stations are listed in Commission Internationale de la Haute Atmosphère 1923.1923 Comptes Rendus des Jours Internationaux 19231923, Troisième PartiePartie, Tableaux des Sondages Réussis, Cambridge Table1. Univ. Press. FigFig. 1: Map showing the locations of the early Asian upper‐air Haude W 19401940. Ergebnisse der allgemeinen meteorologischen Beobachtungen und der observations. White: Kite observations 1931/32 by Waldemar Some of the early Hong Kong Drachenaufstiege an den beiden Standlagern bei Ikengüng und am Edsen‐Gol and Shanghai upper‐air data, 1931/32/ , in: Reportsp fromf theh scientificf expeditionp d to theh northh‐western provincesp off Haude at Edsen‐Gol (left(left, now Juyan) and Ikengüng (right) China under the leadership of Dr. Sven Hedin ‐ The Sino‐Swedish Expedition, during the Sino‐Swedish expedition 1927‐35 led by the Swedish reported in Commission Publication 88, VolVol. IX Meteorology Part 1, Bokförlags Aktiebolaget ThuleThule, Stockholm. geographergeographer, explorerexplorer, photographer and travelogue writer Sven HllHergesell H 1931‐3535. RlResults off aerologicallil ascents 1925‐28, IilInternational CommissionCii forf theh Hedin, see Fig. 2 (Haude, 1940);940); grey: Chinese pilot balloon (all) Internationale de la Haute Exploration of the upper Air, Berlin. and kite (two eastern) stations during 1930‐3535, from west to Atmosphère (1923) and National Research InstInst. of Meteorology 1930‐3535. Bulletin of the Upper Air Current Observations, east: Sian (Xi’an),(), Peipingpg (Beijing),(jg), Nankingg (Nanjing);(jg); black: Hergesell (1931‐35), are still VlVol. I‐VI. AdAcademia i SiSinica i , PeiPi‐Chi‐KKo, NkiNanking. Japanese WWII radiosonde stations in Korea and Manchuria Poli P et al. 2013. ERA Reportp Series 14. duringg 1942‐44,, ffrom west to east: Hailar, Jinzhou,, Dalian,, being digitised at the momentmoment, Stickler A & Brönnimann S 20112011. QQ. JJ. R.R Meteorol.Meteorol Soc.Soc 137: 1400‐1416. StiStickler kl A ett al.l 20102010. BllBull. Amer.A Meteorol.Mt l Soc.S 9191: 741‐751751, DOIDOI:10.1175/2009BAMS2852.1 10 1175/2009BAMS2852 1. Taonan, Changchun,Changchun Incheon. Plot created with R software in the framework of the second Fig. 5: Example of the (left) summer 1931 kite ascents at Ikengüng and (right) winter 1931/32 kite ascents at Edsen‐Gol (both in the Mongolia‐China border region) during the Stickler A et al. 2014a. Bull. Amer. Meteorol. Soc. earlyy online release,, DOI: 10.1175/BAMS/ ‐D‐13‐ packagepg (http://www.rp//// ‐project.org/pj g//) usingg the libraryy 0014700147.1 1. phase of the projectproject, ERA‐ SinoSo‐SwedishSeds Expedition.ped t o . Source:Sou ce: Haudeaude (1940).(90). rworldmap. CLIM2CLIM2. Stickler A et al.al 2014b2014b. Earth Syst.Syst Sci.Sci Data 66: 29‐48, DOIDOI: 1010.5194/essd 5194/essd‐6‐29‐2014.