Comparison between the SPEI_AJ reconstruction and dryness/wetness indices of Lanzhou.

<p>Comparison between the SPEI_AJ reconstruction and dryness/wetness indices of Lanzhou.</p

Patterns of field correlation in our study.

<p>(a) Correlations between the gridded (37.25°N, 104.75°E) SPEI_AJ series with the 0.5×0.5 gridded mean April-June SPEI at the 10-month scale. (b) Correlations between reconstructed SPEI_AJ with the 0.5×0.5 gridded mean April-June SPEI at the 10-month scale (1951–2011 AD).</p

MSM tree-ring STD chronology, running EPS and sample size.

<p>MSM tree-ring STD chronology, running EPS and sample size.</p

Map of the sampling site.

<p>Map of the sampling site.</p

Tree-ring-based reconstruction comparisons among three sites.

<p>(a) The reconstructed precipitation in Liancheng. (b) The SPEI_AJ reconstruction in the Taihe Mountains. (c) The reconstructed precipitation in the Changling-Shoulu region.</p

Tree-ring based temperature comparison among three sites from the northern slope of Qinling Mountains.

<p>(a)FNM <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093504#pone.0093504-Tian1" target="_blank">[26]</a>, (b) MSM (this study) and (c) NWT <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093504#pone.0093504-Liu2" target="_blank">[11]</a>.</p

Correlations between the tree-ring STD chronology and monthly mean temperature (AD 1952–2011), monthly total precipitation (AD 1952–2011) and monthly mean PDSI (AD 1952–2005).

<p>Horizontal dashed lines represent the 95% confidence level.</p

Patterns of field correlation in our study

<p>. (a) Correlations between the reconstructed temperatures with the CRU TS3 temperature during May–July (AD 1952–2009). (b) Correlations between the observed temperatures with the CRU TS3 temperature during May–July (AD 1952–2009).</p

Comparison between the MSM temperatures (red) and other series (black).

<p>(a) Historical documents based on the Longxi Drought index <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093504#pone.0093504-Tan1" target="_blank">[31]</a>. (b) Regional temperature reconstruction for northern China <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093504#pone.0093504-Yi1" target="_blank">[32]</a> and (c) δ¹⁸O time series of stalagmites from Wanxiang Cave, China <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093504#pone.0093504-Zhang1" target="_blank">[33]</a>.</p

Statistics for a split calibration-verification procedure (<i>p</i><0.01).

<p>Statistics for a split calibration-verification procedure (<i>p</i><0.01).</p