The occurrence of heavy rainfall events is expected to undergo significant changes under increasing anthropogenic forcing. South-eastern Europe is reacting rapidly to such changes, therefore understanding and forecasting of precipitation variability is vital to better comprehending environmental changes in this area. Here we present a sub-decadal reconstruction of enhanced rainfall events for the past 2000 years from the Southern Carpathians, Romania using peat geochemistry. Five clear periods of enhanced rainfall are identified at 125-250, 600-900, 1050-1300, 1400-1575 and 1725-1980 CE. Significant runoff is observed during the second half of the Medieval Warm Period, whilst the Little Ice Age was characterised by significant variability. The North Atlantic Oscillation appears to be the main control on regional precipitation, but changes in solar irradiance also seem to play a significant role, together with the Siberian High. Comparison of the data presented here with model outputs confirms the ability of models to predict general trends, and major shifts, but highlights the complexity of the region's hydrological history.

Charles University Faculty of Mathematics and Physics Department of Atmospheric Physics Ke Karlovu 3 Prague 121 16 Czech Republic

Department of Geography and Environmental Sciences Northumbria University Newcastle upon Tyne NE1 8ST United Kingdom

Institute of Geology and Mineralogy University of Cologne 50674 Cologne Germany

Research Institute of the University of Bucharest University of Bucharest 050107 Bucharest Romania

Romanian Academy Institute of Speleology Clinicilor 5 400006 Cluj Napoca Romania

School of Geography and the Environment University of Oxford South Parks Rd Oxford OX1 3QY United Kingdom

School of Ocean and Earth Sciences University of Southampton National Oceanography Centre Waterfront Campus Southampton SO14 3ZH United Kingdom

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Kundzewicz ZW, et al. Flood risk and climate change: global and regional perspectives. Hydrol. Sci. J. 2014;59:1–28.

IPCC. The Physical Science Basis. Working Group I Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, USA (2013).

Min SK, Zhang X, Zwiers FW, Hegerl GC. Human contribution to more-intense precipitation extremes. Nature. 2011;470:378–381. PubMed

Fischer EM, Knutti R. Observed heavy precipitation increase confirms theory and early models. Nat. Clim. Chang. 2016;6:986–991.

Micu, D. M., Dumitrescu, A., Cheval, S. & Bîrsan, M.-V. Climate of the Romanian Carpathians: Variability and Trends, 10.1007/978-3-319-02886-6 (2015).

Zappa G, Shaffrey LC, Hodges KI, Sansom PG, Stephenson DB. A multimodel assessment of future projections of north atlantic and european extratropical cyclones in the CMIP5 climate models. J. Clim. 2013;26:5846–5862.

Woollings T, Gregory JM, Pinto JG, Reyers M, Brayshaw DJ. Response of the North Atlantic storm track to climate change shaped by ocean-atmosphere coupling. Nat. Geosci. 2012;5:313–317.

Mizuta R. Intensification of extratropical cyclones associated with the polar jet change in the CMIP5 global warming projections. Geophys. Res. Lett. 2012;39:1–6.

Ulbrich U, Leckebusch GC, Pinto JG. Extra-tropical cyclones in the present and future climate: A review. Theor. Appl. Climatol. 2009;96:117–131.

Zhang F, Weng Y. Predicting hurricane intensity and associated hazards: A five-year real-time forecast experiment with assimilation of airborne doppler radar observations. Bull. Am. Meteorol. Soc. 2015;96:25–33.

Mihăilescu, C. Clima şi hazardurile Moldovei-evoluţia, starea, predicţia. (Licorn, 2004).

Teodoreanu, E. Little climate optimum in the Carpathian-Danubian-Pontic space. Present Environ. Sustain. Dev. 11 (2017).

Topor, N. Ani ploioşi şi secetoşi în Republica Populară Romînă. (Institutul Meteorlogic, 1964).

Bojariu, R. & Paliu, D.-M. North Atlantic Oscillation Projection on Romanian Climate Fluctuations in the Cold Season in Detecting and Modelling Regional Climate Change and Associated Impacts (eds India, M. B. & Bonillo, D. L.) 345–356 (Springer Berlin Heidelberg, 2001).

Bojariu R, Giorgi F. The North Atlantic Oscillation signal in a regional climate simulation for the European region. Tellus. 2005;57A:641–653.

Swierczynski T, et al. A 1600 yr seasonally resolved record of decadal-scale flood variability from the Austrian Pre-Alps. Geology. 2012;40:1047–1050.

Swierczynski T, et al. Mid- to late Holocene flood frequency changes in the northeastern Alps as recorded in varved sediments of Lake Mondsee (Upper Austria) Quat. Sci. Rev. 2013;80:78–90.

Wirth SB, Glur L, Gilli A, Anselmetti FS. Holocene flood frequency across the Central Alps – solar forcing and evidence for variations in North Atlantic atmospheric circulation. Quat. Sci. Rev. 2013;80:112–128.

Bajard, M. et al. Erosion record in Lake La Thuile sediments (Prealps, France): Evidence of montane landscape dynamics throughout the Holocene. The Holocene, 10.1177/0959683615609750 (2015).

Arnaud F, et al. Erosion under climate and human pressures: An alpine lake sediment perspective. Quaternary Science Reviews. 2016;152:1–18.

Pierre S, et al. 6-kyr record of flood frequency and intensity in the western Mediterranean Alps – Interplay of solar and temperature forcing. Quat. Sci. Rev. 2017;170:121–135.

Wilhelm B, Vogel H, Crouzet C, Etienne D, Anselmetti FS. Frequency and intensity of palaeofloods at the interface of Atlantic and Mediterranean climate domains. Clim. Past. 2016;12:299–316.

Haliuc, A. et al. Palaeohydrological changes over mid and late Holocene in the Carpathian area, central-eastern Europe. Glob. Planet. Change 1–43, 10.1016/j.gloplacha.2017.02.010 (2017).

Diaconu AC, et al. How warm? How wet? Hydroclimate reconstruction of the past 7500 years in northern Carpathians. Romania. Palaeogeogr. Palaeoclimatol. Palaeoecol. 2017;482:1–12.

Longman J, Ersek V, Veres D, Salzmann U. Detrital events and hydroclimate variability in the Romanian Carpathians during the Mid-to-Late Holocene. Quat. Sci. Rev. 2017;167:78–95.

Warken SF, et al. Reconstruction of late Holocene autumn/winter precipitation variability in SW Romania from a high-resolution speleothem trace element record. Earth Planet. Sci. Lett. 2018;499:122–133.

Kern Z, et al. Natural proxy records of temperature- and hydroclimate variability with annual resolution from the Northern Balkan–Carpathian region for the past millennium – Review & recalibration. Quat. Int. 2016;415:109–125.

Tomozeiu R, Stefan S, Busuioc A. Winter precipitation variability and large-scale circulation patterns in Romania. Theor. Appl. Climatol. 2005;81:193–201.

Rimbu N, Stefan S, Necula C. The variability of winter high temperature extremes in Romania and its relationship with large-scale atmospheric circulation. Theor. Appl. Climatol. 2015;121:121–130.

Obreht I, et al. Tracing the influence of Mediterranean climate on Southeastern Europe during the past 350,000 years. Sci. Rep. 2016;6:36334. PubMed PMC

Perşoiu, A. et al. Holocene winter climate variability in Central and Eastern Europe. Sci. Rep. 7 (2017). PubMed PMC

Panagiotopoulos F, et al. Observed Trends and Teleconnections of the Siberian High: A Recently Declining Center of Action. J. Clim. 2005;18:1411–1422.

Ionita M, Chelcea S, Rimbu N, Adler MJ. Spatial and temporal variability of winter streamflow over Romania and its relationship to large-scale atmospheric circulation. J. Hydrol. 2014;519:1339–1349.

Morellón M, et al. Human–climate interactions in the central Mediterranean region during the last millennia: The laminated record of Lake Butrint (Albania) Quat. Sci. Rev. 2016;136:134–152.

Magyari, E. et al. Palaeolimnology of the last crater lake in the Eastern Carpathian Mountains: a multiproxy study of Holocene hydrological changes. Hydrobiologia631 (2009).

Xoplaki, E. et al. Modelling Climate and Societal Resilience in the Eastern Mediterranean in the Last Millennium. Hum. Ecol. 1–17 (2018). PubMed PMC

Roberts N, et al. Palaeolimnological evidence for an east-west climate see-saw in the Mediterranean since AD 900. Glob. Planet. Change. 2012;84–85:23–34.

Longman, J., Veres, D. & Wennrich, V. Utilisation of XRF core scanning on peat and other highly organic sediments. Quat. Int. In Press, (2018).

Urdea P, Reuther AU. Some new data concerning the Quaternary glaciation in the Romanian Carpathians. Geogr. Pannonica. 2009;13:41–52.

Longman J, et al. Periodic input of dust over the Eastern Carpathians during the Holocene linked with Saharan desertification and human impact. Clim. Past. 2017;13:897–917.

Allan M, et al. Mid- and late Holocene dust deposition in western Europe: The Misten peat bog (Hautes Fagnes – Belgium) Clim. Past. 2013;9:2285–2298.

Kylander ME, et al. Potentials and problems of building detailed dust records using peat archives: An example from Store Mosse (the “Great Bog”), Sweden. Geochim. Cosmochim. Acta. 2016;190:156–174.

Stuut JB, Prins MA. The significance of particle size of long-range transported mineral dust. PAGES Mag. 2014;22:70–71.

Finsinger, W. et al. Holocene fire-regime changes near the treeline in the Retezat Mts. (Southern Carpathians, Romania). Quaternary International (2016).

Feurdean A, et al. 12,000-Years of fire regime drivers in the lowlands of transylvania (Central-Eastern Europe): A data-model approach. Quat. Sci. Rev. 2013;81:48–61.

Diaconu, A.-C., Grindean, R., Panait, A. & Tanţău, I. Late Holocene palaeohydrological changes in a Sphagnum peat bog from NW Romania based on testate amoebae. Stud. UBB Geol. 60 (2016).

Hubay, K. et al. Holocene environmental changes as recorded in the geochemistry of glacial lake sediments from Retezat Mountains, South Carpathians. Quat. Int, 10.1016/J.QUAINT.2018.02.024 (2018).

Cristea G, et al. Carbon isotope composition as indicator for climatic changes during the middle and late Holocene in a peat bog from Maramures Mountains (Romania) The Holocene. 2013;24:15–23.

Feurdean A, et al. Last Millennium hydro-climate variability in Central-Eastern Europe (Northern Carpathians. Romania). The Holocene. 2015;25:1179–1192.

Chiriloaei F, Rǎdoane M, Perşoiu I, Popa I. Late Holocene history of the Moldova River Valley. Romania. Catena. 2012;93:64–77.

Rădoane, M. et al. History of Holocene fluvial activity in Romania: evidences based on absolute dating. Proc. 33rd Rom. Geomorphol. Symp. 92–96 (2017).

Feurdean A, Tanţâu I, Fârcaş S. Holocene variability in the range distribution and abundance of Pinus, Picea abies, and Quercus in Romania; implications for their current status. Quat. Sci. Rev. 2011;30:3060–3075.

Forray FL, et al. A Late Holocene environmental history of a bat guano deposit from Romania: an isotopic, pollen and microcharcoal study. Quat. Sci. Rev. 2015;127:141–154.

Onac BP, et al. A 2500-yr late Holocene multi-proxy record of vegetation and hydrologic changes from a cave guano-clay sequence in SW. Romania. Quat. Res. 2015;83:437–448.

Panait A, et al. Hydrological conditions and carbon accumulation rates reconstructed from a mountain raised bog in the Carpathians: A multi-proxy approach. CATENA. 2017;152:57–68.

Magny M. Holocene climate variability as reflected by mid-European lake-level fluctuations and its probable impact on prehistoric human settlements. Quat. Int. 2004;113:65–79.

Wilhelm B, et al. 1400years of extreme precipitation patterns over the Mediterranean French Alps and possible forcing mechanisms. Quat. Res. 2012;78:1–12.

Arnaud F, et al. Lake Bourget regional erosion patterns reconstruction reveals Holocene NW European Alps soil evolution and paleohydrology. Quat. Sci. Rev. 2012;51:81–92.

Gałka M, Apolinarska K. Climate change, vegetation development, and lake level fluctuations in Lake Purwin (NE Poland) during the last 8600 cal. BP based on a high-resolution plant macrofossil record and stable isotope data (δ13C and δ18O) Quat. Int. 2014;328:213–225.

Schnitchen C, et al. Reconstructing hydrological variability from testate amoebae analysis in Carpathian peatlands. J. Paleolimnol. 2006;36:1–17.

Feurdean A, Klotz S, Mosbrugger V, Wohlfarth B. Pollen-based quantitative reconstructions of Holocene climate variability in NW Romania. Palaeogeogr. Palaeoclimatol. Palaeoecol. 2008;260:494–504.

Charman DJ, Blundell A, Chiverrell RC, Hendon D, Langdon PG. Compilation of non-annually resolved Holocene proxy climate records: stacked Holocene peatland palaeo-water table reconstructions from northern Britain. Quat. Sci. Rev. 2006;25:336–350.

Gałka M, et al. Disentangling the drivers for the development of a Baltic bog during the Little Ice Age in northern Poland. Quat. Int. 2014;328–329:323–337.

Marcisz K, et al. Long-term hydrological dynamics and fire history over the last 2000 years in CE Europe reconstructed from a high-resolution peat archive. Quat. Sci. Rev. 2015;112:138–152.

Levanič T, Popa I, Poljanšek S, Nechita C. A 323-year long reconstruction of drought for SW Romania based on black pine (Pinus Nigra) tree-ring widths. Int. J. Biometeorol. 2013;57:703–714. PubMed

Brázdil R, et al. European floods during the winter 1783/1784: Scenarios of an extreme event during the ‘Little Ice Age’. Theor. Appl. Climatol. 2010;100:163–189.

Magny M, et al. Geoscientific Instrumentation Methods and Data Systems North–south palaeohydrological contrasts in the central Mediterranean during the Holocene: tentative synthesis and working hypotheses. Clim. Past. 2013;9:2043–2071.

Drăguşin V, et al. Constraining Holocene hydrological changes in the Carpathian–Balkan region using speleothem δ18O and pollen-based temperature reconstructions. Clim. Past. 2014;10:1363–1380.

Krichak SO, Alpert P. Signatures of the NAO in the atmospheric circulation during wet winter months over the Mediterranean region. Theor. Appl. Climatol. 2005;82:27–39.

Ólafsdóttir KB, Geirsdóttir Á, Miller GH, Larsen DJ. Evolution of NAO and AMO strength and cyclicity derived from a 3-ka varve-thickness record from Iceland. Quat. Sci. Rev. 2013;69:142–154.

Obreht I, et al. Shift of large-scale atmospheric systems over Europe during late MIS 3 and implications for Modern Human dispersal. Sci. Rep. 2017;7:5848. PubMed PMC

Benito G, Macklin MG, Zielhofer C, Jones AF, Machado MJ. Holocene flooding and climate change in the Mediterranean. Catena. 2015;130:13–33.

Steinhilber F, et al. 9,400 Years of Cosmic Radiation and Solar Activity From Ice Cores and Tree Rings. Proc. Natl. Acad. Sci. 2012;109:5967–5971. PubMed PMC

Shindell DT, Schmidt GA, Mann ME, Rind D, Waple A. Solar forcing of regional climate change during the Maunder Minimum. Science. 2001;294:2149–2152. PubMed

Czymzik M, Muscheler R, Brauer A. Solar modulation of flood frequency in central Europe during spring and summer on interannual to multi-centennial timescales. Clim. Past. 2016;12:799–805.

Benito G, et al. Recurring flood distribution patterns related to short-term Holocene climatic variability. Sci. Rep. 2015;5:1–8. PubMed PMC

Martin-Puertas C, et al. Regional atmospheric circulation shifts induced by a grand solar minimum. Nat. Geosci. 2012;5:397–401.

Nichols, J. E. & Huang, Y. Hydroclimate of the northeastern United States is highly sensitive to solar forcing. Geophys. Res. Lett. 39 (2012).

Damon PE, Jirikowic JL. The Sun as a Low-Frequency Harmonic Oscillator. Radiocarbon. 1992;34:199–205.

Lüdecke H-J, Weiss CO, Hempelmann A. Paleoclimate forcing by the solar De Vries/Suess cycle. Clim. Past Discuss. 2015;11:279–305.

Swindles GT, Patterson RT, Roe HM, Galloway JM. Evaluating periodicities in peat-based climate proxy records. Quat. Sci. Rev. 2012;41:94–103.

Yu S-Y. Centennial-scale cycles in middle Holocene sea level along the southeastern Swedish Baltic coast. Geol. Soc. Am. Bull. 2003;115:1404.

Woollings T, Lockwood M, Masato G, Bell C, Gray L. Enhanced signature of solar variability in Eurasian winter climate. Geophys. Res. Lett. 2010;37:1–6.

Fordham DA, et al. PaleoView: a tool for generating continuous climate projections spanning the last 21 000 years at regional and global scales. Ecography (Cop.). 2017;40:1348–1358.

Liu Z, et al. Evolution and forcing mechanisms of El Niño over the past 21,000 years. Nature. 2014;515:550–553. PubMed

Otto-Bliesner BL, et al. Coherent changes of southeastern equatorial and northern African rainfall during the last deglaciation. Science. 2014;346:1223–7. PubMed

Collins WD, et al. The Community Climate System Model Version 3 (CCSM3) J. Clim. 2006;19:2122–2143.

Yeager SG, et al. The Low-Resolution CCSM3. J. Clim. 2006;19:2545–2566.

International Hydrological Programme, Bodo, B. & Global Runoff Data Center. Augmented Monthly Flow Rates of World Rivers (except former Soviet Union). NCAR Research Data Archive, 10.5065/D61G0JGZ (2001).

Pauling A, Luterbacher J, Casty C, Wanner H. Five hundred years of gridded high-resolution precipitation reconstructions over Europe and the connection to large-scale circulation. Clim. Dyn. 2006;26:387–405.

Smerdon JE, et al. Comparing proxy and model estimates of hydroclimate variability and change over the Common Era. Clim. Past. 2017;13:1851–1900.

Cristea, V. Fitosociologie şi vegetaţia României. (Babes-Bolyai University Press, 1993).

Fărcaş, I. & Sorocovschi, V. The climate of the Retezat Mountains in The Retezat National Park, Ecological Studies (ed. Popovici, I.) 13–20 (West Side Computers, 1992).

Croudace, I. W., Rindby, A. & Rothwell, R. G. ITRAX: description and evaluation of a new multi-function X-ray core scanner in New Techniques in Sediment Core Analysis (ed. Rothwell, R. G.) 51–63, 10.1144/GSL.SP.2006.267.01.04 (Geological Society, London, Special Publications, 2006).

Kylander ME, et al. A novel geochemical approach to paleorecords of dust deposition and effective humidity: 8500 years of peat accumulation at Store Mosse (the ‘Great Bog’), Sweden. Quat. Sci. Rev. 2013;69:69–82.

Reimer P, et al. IntCal13 and Marine13 Radiocarbon Age Calibration Curves 0–50,000 Years cal BP. Radiocarbon. 2013;55:1869–1887.

Grinsted A, Moore JC, Jevrejeva S. Application of the cross wavelet transform and wavelet coherence to geophysical time series. Nonlinear Process. Geophys. 2004;11:561–566.

Torrence C, Compo GP, Torrence C, Compo GP. A Practical Guide to Wavelet. Analysis. Bull. Am. Meteorol. Soc. 1998;79:61–78.

Percival, D. B. & Walden, A. T. Spectral Analysis for Physical Applications. (Cambridge University Press, 1993).

Thomson DJ. Spectrum estimation and harmonic analysis. Proc. IEEE. 1982;70:1055–1096.

Ghil M, et al. Advanced spectral methods for climatic time series. Rev. Geophys. 2002;40:1003.

Mayewski PA, Maasch KA. Recent warming inconsistent with natural association between temperature and atmospheric circulation over the last 2000 years. Clim. Past Discuss. 2006;2:327–355.

Olsen J, Anderson NJ, Knudsen MF. Variability of the North Atlantic Oscillation over the past 5,200 years. Nat. Geosci. 2012;5:1–14.

Trouet V, et al. Persistent Positive North Atlantic Oscillation Mode Dominated the Medieval Climate Anomaly. Science (80-.). 2009;324:78–80. PubMed

Climate and land-use as the main drivers of recent environmental change in a mid-altitude mountain lake, Romanian Carpathians