Two millennia of Main region (southern Germany) hydroclimate variability
<p>A reconstruction of hydroclimate with an annual resolution covering millennia for a geographically limited region in continental Europe significantly improves our knowledge of past climate dynamics. With the use of an extensive collection of oak ring-width series (<i>Quercus robur<...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-09-01
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| Series: | Climate of the Past |
| Online Access: | https://www.clim-past.net/15/1677/2019/cp-15-1677-2019.pdf |
| Summary: | <p>A reconstruction of hydroclimate with an annual
resolution covering millennia for a geographically limited region in
continental Europe significantly improves our knowledge of past climate
dynamics. With the use of an extensive collection of oak ring-width series
(<i>Quercus robur</i> and <i>Quercus petraea</i>) from living trees, historic timbers and subfossil alluvial wood
deposits from the Main River region in southern Germany, a regional,
2000-year long, seasonally resolved hydroclimate reconstruction for the
Main region has been developed. Climate-growth response analysis has been
performed with daily climate records from AD 1900 onwards. To test the
stability of the developed transfer function, a bootstrapped transfer
function stability test (BTFS) as well as a classical calibration/verification approach have been implemented to study climate-growth model
performance. Living oak trees from the Main River region show a significant
sensitivity to the precipitation sum from 26 February to 6 July (spring to
midsummer) during the full (<span class="inline-formula"><i>r</i>=0.49</span>, <span class="inline-formula"><i>p</i><i><</i>0.01</span>, <span class="inline-formula"><i>N</i>=116</span>) and
split (<span class="inline-formula"><i>r</i>=0.58</span>, <span class="inline-formula"><i>p</i><i><</i>0.01</span>, <span class="inline-formula"><i>N</i>=58</span>) calibration periods. BTFS
confirmed the stability of the developed transfer function. The developed
precipitation reconstruction reveals high variability on a high- to
mid-frequency scale during the past two millennia. Very dry spring to
midsummer seasons lasting multiple years appeared in the decades AD 500/510s, 940s, 1170s, 1390s and 1160s. At the end of the AD 330s, a
persistent multi-year drought with drastically reduced rainfall (with regard to 1901–2000) could be identified, which was the driest decade over the past
2000 years in this region. In the AD 550s, 1050s, 1310s and 1480s,
multi-year periods with high rainfall hit the Main region. In spring to
midsummer of AD 338, precipitation was reduced by <span class="inline-formula">∼38</span> %
and in AD 357 it increased by <span class="inline-formula">∼39</span> %. The presented
hydroclimate reconstruction and its comparison to other records reveal
interesting insights into the hydroclimate dynamics of the geographically
limited area over the Common Era, in addition to revealing noticeable temporal
differences.</p> |
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| ISSN: | 1814-9324 1814-9332 |