Seasonal Reconstruction of Summer Precipitation Variability and Dating of Flood Events for the Millennium Between 3250 and 2250 Years BC for the Main Region, Southern Germany

A novel computer-aided tree-ring analysis software (CATS): oak earlywood vessel size reveals a clear spring heat sum response

“…The samples used in this study to stress test CATS are part of the Holocene oak chronology (HOC) Hohenheim (located at University of Hohenheim) containing a large number of precisely dated ancient to modern trees spanning the entire Holocene (Friedrich et al 2004). This collection has been used to address different questions regarding climate dynamics and environmental changes over the past 12 millennia (Friedrich et al 2001(Friedrich et al , 2006Land et al 2015;Land 2014;Schönbein et al 2015;Spurk et al 2002).…”

“…We developed a MATLAB Ò (The MathWorks Ò 2013) script that aggregates the meteorological data for each year altering (1) the length of the data interval used for correlation (from 11 to 111 days in steps of five days) and (2) the starting date of the data derived from (1) between January 1 and December 15 (Schönbein 2011). A Pearson correlation between each newly generated meteorological series and each vessel chronology was calculated.…”

“…For Central Europe, millennia-length tree-ring chronologies as well as many precisely dated wooden samples are available (Friedrich et al 2004;Leuschner et al 2002;Spurk et al 1998) spanning the entire Holocene. These climate tree-ring archives are perfectly suited for investigations into past climate variability and environmental changes Land 2014;Schönbein et al 2015;Spurk et al 2002) on a spatio-temporal scale. Trees develop an immense number of earlywood vessels of varying size and shape every growing season, thus recording particular weather conditions.…”

“…Dendroclimatologists use classical tree ring proxies (ring width or maximum latewood density) to reconstruct climate variability from thousands of years ago with annual to seasonal resolution (Büntgen et al 2011;Esper et al 2013;Land et al 2015;Schönbein et al 2015;Seftigen et al 2013;Wilson et al 2013). These proxies are very common and an extensive network of tree ring series is currently available for the entire Northern Hemisphere (St. George 2014).…”

Two millennia of Main region (southern Germany) hydroclimate variability

“…However, due to a lack of samples from ancient (subfossil) wood before the Middle Ages, there are far less hydroclimate reconstructions developed from tree rings before that epoch. Nevertheless, some studies addressed this challenge and yield the unique possibility to investigate hydroclimate fluctuations beyond the Common Era (Land et al, 2015;Büntgen et al, 2011;Pechtl and Land, in press;Schönbein et al, 2015). For accurate climate model assessment, it is crucial to understand the full range of natural rainfall variability, which would allow to suit current models.…”