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We established a tree-ring width series from one Yunnan Douglas fir (Pseudotsuga forrestii) stand near the Mingyong glacier terminus of Meili Snow Mountain, southeastern Tibetan Plateau. Correlation analyses indicated that radial growth of Yunnan Douglas firs is largely controlled by variations in winter (November-March) precipitation. The precipitation reconstruction model accounts for 37% of the actual precipitation variance during the common period 1954-2012. Spatial correlations with the gridded precipitation data reveal that the winter precipitation reconstruction represents regional precipitation changes over the southeastern Tibetan Plateau. By comparing our results with other regional tree-ring records, a distinctive amount of common dry and humid periods were found. Our winter precipitation reconstruction shows profound similarities with Salween river streamflow signals as well as regional glacial activity. Cross-wavelet analysis reveals solar and ENSO influences on precipitation and streamflow variations in the southeastern Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Drought is a common natural disaster in arid Central Asia, and the severity and frequency of drought and other hydroclimatic events are critical to the region's ecology and its residents' livelihoods. In particular, water resource management requires reliable knowledge of climatic variability and annual and centennial drought patterns. In this paper, we establish a 587-year tree ring chronology using 215 Schrenk spruce ( Picea schrenkiana Fisch. et Mey) samples and reconstruct a spring Palmer Drought Severity Index ( PDSI) for the inner Tianshan Mountains spanning the 1645-2008 period. The reconstruction explains 40.3% of the variance during the sub-period for which we also have reliable observational data (1938-2005). Cross-validation during this common period also supports our reconstruction model. Spatial correlation analyses with gridded PDSI data show that our PDSI reconstruction reveals a strong regional drought signal for the central and western Tianshan Mountains. [ABSTRACT FROM AUTHOR]

We reconstructed previous July–current April total precipitation in the upper Ili-Balkhash Basin of Central Asia, using a transfer equation based on the correlation between regional tree-ring width series and local precipitation data. Dry periods were identified from 1586–1612, 1637–1669, 1695–1721, 1759–1782, 1804–1864, 1907–1930 and 1974–1993, while wet periods occurred from 1560–1585, 1613–1636, 1670–1694, 1722–1758, 1783–1803, 1865–1906, 1931–1973 and 1994–2006. Spatial correlation analysis indicates that our precipitation reconstruction is broadly representative of precipitation in the entire Ili-Balkhash Basin. The precipitation timeseries is also strongly related to streamflow measurements, revealing that variations in precipitation in the upper Ili-Balkhash Basin have a dramatic influence on streamflow into Lake Balkhash. The precipitation reconstruction also compares well with various streamflow reconstructions from the Tien Shan, and exhibits an increasing streamflow trend in the 1980s through 2000s. Spectral analysis showed significant 60-, 33-, 11-, 2.8- and 2.1-year cycles over the past 447 years. Our 447-year precipitation reconstruction provides the basis for comparing past and present hydroclimate changes, which will be important for detection and attribution of hydroclimate variation in the Ili-Balkhash Basin. [ABSTRACT FROM AUTHOR]

In a warming world, water scarcity is one of the main concerns for sustainable development and human well-being in inner Asia. Due to the lack of instrumental streamflow records, the natural variability of the water supply from inner Asian rivers is not well understood from a long-term perspective. Here, we have reconstructed the streamflow of Upper Irtysh River from AD 1500 to 2010, based on the tree-ring width indices of spruce ( Picea obovata) and larch ( Larix sibirica) from the Altay Mountains. The reconstruction explains 48.4 % of the recorded streamflow variance over the common period 1958-2008. This streamflow reconstruction is representative of regional moisture conditions over the Irtysh River basin area. Some significant spectral peaks are identified, and suggest the influence of natural forcing on the streamflow of the Upper Irtysh River, such as ENSO and solar activity. The linkages of our reconstruction with sea surface temperature in the northern Indian Ocean, eastern equatorial Pacific Ocean, and equatorial Atlantic Ocean suggest the connection of regional streamflow variations to large-scale atmospheric circulation. We also find that there is the relationship between regional drought/streamflow variations in inner Asia and the interaction of the mid-latitude Westerlies and Asian summer monsoon. Our 511-year streamflow reconstruction provides a long-term perspective on current and twentieth century wet and dry events in the Irtysh River basin, is useful to guide predictions of future variability, and aids future water resource management. [ABSTRACT FROM AUTHOR]

Gauged river flow records from China generally span only a few decades, which hampers the detection of long-term, decadal- to centennial-scale cycles and trends in streamflow variability. New and updated tree-ring chronologies help reconstructed the water-year (October–September) streamflow for the Aksu River, which is an important river at the edge of the Taklimakan Desert that drains into the Tarim Basin. The reconstruction dates back to 1692 and has an adjusted r 2 of 0.61 (1957–2006). Based on frequency, intensity and duration of droughts and pluvial events, the lowest streamflows occurred in the 1920s. Since then streamflow has continuously increased, and was exceptionally rapidly after the 1960s, until today. The start and end of the 20th century to the present were the highest streamflow periods. The mid-20th century was the longest and driest period over the past 300 yr. The reconstructed streamflow series has a strong positive correlation with the North Atlantic Oscillation Index. Changes in mid-latitude circulation patterns influencing precipitation may have indirectly resulted in streamflow variations along the Aksu River over the past 300 yr. The rapid increase and the exceptional streamflows of the 1960s are likely linked with global warming and mid-latitude atmospheric circulation changes. [ABSTRACT FROM AUTHOR]

The western Tianshan Mountains are a very important source of water. The area is dominated by westerly winds and is important in global change research. In this paper, we combine two tree-ring width chronologies, meteorological data from the Climatic Research Unit (CRU), a standardized precipitation-evapotranspiration index (SPEI) and Palmer Drought Severity Index (PDSI) to analyze radial growth response to climate. Studies show moisture from the previous July to current June was consistently the dominant climatic factor accounting for interannual variation of tree-ring width in the western Tianshan Mountains. Then, we reconstruct the precipitation, SPEI and PDSI, and the three series are verified with mathematical methods and other observation data. Power spectral and wavelet analyses reveal significant 2- to 6-year high-frequency cycles and a 17-year low-frequency cycle. Moisture has varied as four wetter periods and four drier periods over the past century. We show that over all northern slopes of the Tianshan Mountains, moisture change has been rarely consistent. From the 1980s to present, the climate has had the longest, most significant and rapid wetting period in the past century. The moisture variability pertains to most areas of the western Tianshan Mountains, especially the northern slope of the mountains in Kyrgyzstan. Our results indicate a strong negative relationship between the Summer North Atlantic Oscillation (SNAO) and moisture in the western Tianshan Mountains. The moisture variability may have been controlled by the SNAO in the past century, and may be associated with large-scale oscillation in the climate system. [ABSTRACT FROM AUTHOR]

Based on the significant positive correlations between the regional tree-ring width chronology and local climate data, the total precipitation of the previous July to the current June was reconstructed since AD 1760 for the northwestern Chinese Altay. The reconstruction model accounts for 40.7 % of the actual precipitation variance during the calibration period from 1959 to 2013. Wet conditions prevailed during the periods 1764-1777, 1784-1791, 1795-1805, 1829-1835, 1838-1846, 1850-1862, 1867-1872, 1907-1916, 1926-1931, 1935-1943, 1956-1961, 1968-1973, 1984-1997, and 2002-2006. Dry episodes occurred during 1760-1763, 1778-1783, 1792-1794, 1806-1828, 1836-1837, 1847-1849, 1863-1866, 1873-1906, 1917-1925, 1932-1934, 1944-1955, 1962-1967, 1974-1983, 1998-2001, and 2007-2012. The spectral analysis of the precipitation reconstruction shows the existence of some cycles (15.3, 4.5, 3.1, 2.7, and 2.1 years). The significant correlations with the gridded precipitation dataset revealed that the precipitation reconstruction represents the precipitation variation for a large area of the northern part of inner Asia. A comparison with the precipitation reconstruction from the southern Chinese Altay shows the high level of confidence for the precipitation reconstruction for the northwestern Chinese Altay. Precipitation variation of the northwestern Chinese Altay is positively correlated with sea surface temperatures in tropical oceans, suggesting a possible linkage of the precipitation variation of the northwestern Chinese Altay to the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). The synoptic climatology analysis reveals that there is the relationship between anomalous atmospheric circulation and extreme climate events in the northwestern Chinese Altay. [ABSTRACT FROM AUTHOR]

We have developed a 272-year ring-width chronology of Chinese pine ( Pinus tabulaeformis ) growing in the Huanglong Mountains, North China. Climatic response analyses revealed that mean January–July Palmer drought severity index (PDSI) has positive effect on the radial growth of pine trees. Based on the relationships, the mean January–July PDSI was reconstructed for the period from 1760 to 2010. The percentage of variance in the data explained by the reconstruction was 41% during the calibration period of 1950–2010. Spatial correlation analyses between the PDSI reconstruction and gridded PDSI data show that the PDSI reconstruction captures regional drought variations over the environmentally-sensitive area linked to the East Asian summer monsoon. Relatively wet periods are identified for AD 1766–1781, 1795–1804, 1811–1821, 1838–1859, 1884–1889, 1909–1914, 1937–1977 and 2003–2008. Dry conditions prevailed during AD 1760–1765, 1782–1794, 1805–1810, 1822–1837, 1860–1883, 1890–1908, 1915–1936, 1978–2002 and 2009–now. There is a reasonable agreement with dry/wet periods previously estimated from tree-ring data of the Kongtong Mountains of the Loess Plateau. Spatial correlation analyses with sea surface temperature in the Pacific Ocean and tropical Indian Ocean indicated that the Asian summer monsoon circulations play a role in modulating drought variations in the study area whereas the effects of the Pacific Decadal Oscillation are relatively strong. [ABSTRACT FROM AUTHOR]

We developed a Faxon fir ( Abies faxoniana) tree-ring width chronology at the timberline in the western Qinling Mountains, China. Herein February-July mean temperature was reconstructed for Zhouqu in the western Qinling Mountains back to AD 1650 based on the standard chronology. The climate/tree-growth model accounts for 43.5% of the instrumental temperature variance during the period 1972-2006. Spatial correlation analyses with the gridded temperature data shows that the temperature reconstruction captures regional climatic variations over central and southeast China, and strong teleconnections with the nearby High Asia. There is a good agreement with cold and warm periods previously estimated from tree-rings in Nepal, India and southwest China. The temperature re-construction indicates that there was pronounced cooling in Zhouqu during the Maunder Minimum (late 1600s to early 1700s). The cold period (1813-1827) of the temperature reconstruction coincide with the volcanic eruptions. Significant spectral peaks are found at 56.9, 22.3, 11.4, 2.9, 2.8, 2.6, 2.2 and 2.0 years. The spatial correlation patterns between our temperature reconstruction and SSTs of the Atlantic and Pacific Oceans suggest a connection between regional temperature variations and the atmospheric circulations. It is thus revealed that the chronology has enough potential to reconstruct the climatic variability further into the past. [ABSTRACT FROM AUTHOR]

Cores of Pinus tabulaformis from Tianshui were subjected to densitometric analysis to obtain mean earlywood density data. Climate response analysis indicates that May–June maximum temperature is the main factor limiting the mean earlywood density (EWD) of Chinese pine trees in the Shimen Mountains. Based on the EWD chronology, we have reconstructed May–June maximum temperature 1666 to 2008 for Tianshui, north central China. The reconstruction explains 40.1% of the actual temperature variance during the common period 1953–2008. The temperature reconstruction is representative of temperature conditions over a large area to the southeast and northwest of the sampling site. Preliminary analysis of links between large-scale climatic variation and the temperature reconstruction shows that there is a relationship between extremes in spring temperature and anomalous atmospheric circulation in the region. It is thus revealed that the mean earlywood density chronology of Pinus tabulaformis has enough potential to reconstruct the temperature variability further into the past. [ABSTRACT FROM AUTHOR]

An annual ( July to June) precipitation reconstruction for the period AD 1760-2010 was developed from a Picea crassifolia regional tree-ring chronology from two sites in the northern mountainous region of the Hexi Corridor, NW China. This reconstruction explains 52.1% of the actual precipitation variance during the period 1951 to 2010. Spatial correlations with gridded land-surface data reveal that our reconstruction contains a strong regional precipitation signal for the Hexi Corridor and for the southern margin of the Badain Jaran Desert. Significant spectral peaks were identified at 31.9, 11.1, 8.0, 7.0, 3.2, 2.6 and 2.2 years. A large-scale comparison indicates that our reconstruction is more consistent with climate records of a Westerly-dominated Central Asia, and that the Westerlies have a greater impact on the precipitation in this region than the Asian summer monsoon. Our reconstructed precipitation series is significantly correlated with sea-surface temperature ( SST) in the tropical Atlantic Ocean (positive), the tropical Indian Ocean (positive), the western tropical Pacific Ocean (positive), and the western North Pacific Ocean (negative). The spatial correlation patterns between our precipitation reconstruction and SSTs of the Atlantic and Pacific Oceans suggest a connection between regional precipitation variations and the high-mid-latitude northern atmospheric circulations ( Westerlies and Asian summer monsoon). [ABSTRACT FROM AUTHOR]

Abstract: Three robust tree-ring density chronologies were developed for the western Tianshan Mountains of northwestern China. The chronologies were significantly correlated and form a regional chronology (GLD). The GLD had significant and positive correlations with temperature of warm seasons. Based on this relationship, the mean minimum temperatures of May to August were reconstructed using the GLD chronology for the period AD 1657 to 2008. The temperature reconstruction exhibited temperature patterns on interannual to centennial timescales, and showed that the end of the 20th century is the warmest period in the past 352years. The reconstructed temperature variation has a teleconnection with large-scale atmospheric–oceanic variability and captures long- and broad-scale regional climatic variations. [Copyright &y& Elsevier]

In this paper, ring-width chronologies of pine trees ( Pinus sylvestris var. mongolica) from one sampling site in the northern Greater Higgnan Mountains, China, were constructed. The results of growth-climate responses show that mean temperature is the limiting factor affecting radial growth of pine trees in the study area. Consequently, mean temperature from May to October from 1717 to 2008 has been reconstructed using the standard chronology. For the calibrated period (1957-2008), the explained variance of the reconstruction is 57%. The characteristics of the reconstruction expose that mean temperature has increased since the 1970s, and the decade 2000s and 1990s are also ranked as the warm decades on record. However, this period from 1970s to now is not exceptional within the past 300 years. By applying an 11-year moving average to the reconstruction, three warm periods and three cold periods are evident. The warm and cold periods of the reconstructed mean temperature correspond well with other reconstructions. Power spectral and wavelet analysis demonstrated the existence of significant ∼70- and ∼100-year cycles of variability. Furthermore, the reconstruction and North Atlantic Oscillation Index showed a significant positive correlation ( r = 0.34, n = 136, p < 0.0001). Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Seven different tree-ring parameters were obtained from Chinese pine ( Pinus tabulaeformis) in the Changling Mountains, China. The chronologies were analyzed individually and then compared with each other. The climate response analysis shows that total precipitation (September-July) is the main factor limiting the radial growth of Chinese pine in the Changling Mountains. Thus, the residual earlywood width chronology was used to estimate precipitation (September-July) for the period AD 1691-2006, and explained 46.9% of the precipitation variance. Drought events in our reconstruction are compared to historical archives for Gansu and north-central China. The results reveal the climatic extremes over much of Gansu. Some events have had profound impacts on the Gansu people over the past several centuries. Spatial analysis shows that the precipitation reconstruction has strong common signals for North-central China. The reconstructed series is correlated significantly with Helan Mountains Palmer drought severity index (PDSI), as well as with previous results from Jiuquan, Shandan, Huashan, Luya Mountains, and even the state of Mongolia. Our results suggest that some dry periods are coincident with solar minima over the past several hundred years. Multitaper spectral analysis reveals the existence of significant 24.4-year, 12.2-year, and 2.4- to 3.4-year periods of variability. [ABSTRACT FROM AUTHOR]

Wood from Siberian larch ( Larix sibirica Ledeb.) was collected in Hoboksar County, Xinjiang. Mean latewood densities (LWD) were measured by X-ray densitometry; individual series were first cross-dated and then combined to form a standard chronology. We developed a warm-season (June-August) temperature reconstruction of Zajsan Lake area in East Kazakhstan that spans 1600-2002 based on the standard chronology (LWD). The climate/tree-growth model accounts for 39.1% of the temperature variance from 1901 to 2002 and shows cold phase during the late 1600s early 1700s followed by a warmer period, with cooling again in the late 1700s early 1800s. Several severely cold warm seasons coincide with major volcanic eruptions. Some of the temperature variations also correspond to variations in solar activity. The similarities in trends of the Zajsan chronology (LWD) and the Qinghe chronology (LWD) in Altai Mountain show that there are common large-scale climatic forcings in Central Asian. The low-frequency change of temperature reconstruction is correlated positively with Northern Hemisphere temperatures. Copyright © 2011 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Reports on variations in the spring precipitation day numbers reconstructed from tree rings in the Urumqi River drainage in the Tianshan Mountains in China over the last 370 years until 2003. Types of tree-ring width chronologies during the period; Effectiveness of dendrochronology in reconstructing the number of the precipitation day.

Using mean earlywood density data from Pinus koraiensis cores, we reconstructed the April–June mean minimum temperature from 1797 to 2015 for the Changbai Mountains. The reconstruction explained 52.6% of the actual mean minimum temperature variance during 1901–2015. After smoothing with an 11‐year moving average, we identified three major cold periods (1797–1875, 1881–1899, and 1903–1946) and three major warm periods (1876–1880, 1900–1902, and 1947–2015) in the reconstructed series. Spatial correlation showed that the reconstruction contained climatic signals for a large area including most of northeast China, especially the Bohai Rim region and the eastern side of the Mongolian Plateau. A comparison between the newly reconstructed temperature series for the surrounding areas reveals similar variations, particularly in the warming trend during the second half of the 20th century. The driving factors of the mean minimum temperature were influenced mainly by the interaction of solar activity and large‐scale atmospheric‐oceanic variability. The reconstructed series provides a basis for understanding past climate change in the Changbai Mountains and for predicting future climate change trends in Northeast China. [ABSTRACT FROM AUTHOR]

In this study, a 177-year April–June Palmer Drought Severity Index (PDSI) for the southern slopes of the Altay Mountains (China) was reconstructed based on the earlywood width of 96 Siberian spruce (Picea obovata Ledeb.) samples located at eight different sites. The reconstructed PDSI tracked the observed data well (r = 0.723, p <.0001, n = 52). This PDSI reconstruction captures some drought years and periods noted in historical documents, and it agrees well with other hydroclimatic reconstructions for the surrounding area. The 22-, 11-, 2.3-, and 2.1-year cycles of the reconstruction and the spatial correlation with sea surface temperature revealed that the variability of the PDSI for the study area might be influenced by both the Schwabe cycle of solar activity and the interannual oscillation of land–atmosphere–ocean circulation systems. Spatial correlation also showed the reconstruction contained climatic signals, being representative of a larger area extending from northern Xinjiang to northeastern Kazakhstan and a part of southern Russia. Synoptic climatology analysis revealed a relationship between anomalous atmospheric circulation and wet/dry years on the southern slopes of the Altay Mountains in China and its surrounding area. [ABSTRACT FROM AUTHOR]

Forty-one living larch (Larix principis-rupprechtii) trees collected from two sampling sites in 1310-1530 m a.s.l. in the southern Greater Higgnan Mountains in the northeastern China are used to develop a regional tree-ring width chronology. The credible chronology spans 185 years from 1830 to 2014. The results of correlation analyses indicate that moisture is the main climatic factor controlling radial growth of larch trees in this mountainous area. Spatial correlation proves that the regional tree-ring width chronology contains climatic signals representative for a large area including the eastern Mongolian Plateau and Nuluerhu Mountains. A comparison between the newly developed chronology and a May-July Palmer Drought Severity Index (PDSI) reconstruction for the Ortindag Sand Land reveals similar variations, particularly in the low-frequency domain. The tree-ring records also capture a severe and sustained drying trend recorded in the 1920s across a wide area of northern China. [ABSTRACT FROM AUTHOR]

Broad-leaved tree species have rarely been used in dendroclimatology and dendrohydrology in arid Central Asia. Core samples of Populus xjrtyschensis Ch. Y. Yang were collected along the Tuoshigan River in 2015. Correlation and response analyses indicate that the radial growth of P . xjrtyschensis shows a strong relationship to streamflow and a weak response to climate. We suggest that summer streamflow is a limiting factor for the radial growth of P. xjrtyschensis along the Tuoshigan River. Using tree-ring data from P. xjrtyschensis , we reconstructed the historical summer streamflow of the Tuoshigan River back to 1900. The reconstruction has an adjusted r 2 of 0.407 (1957–2006). Statistical verification methods and historical documents indicate that the reconstructed series is stable and reliable. The results reveal that the beginning of the 20th century and the end of the 20th century to the present experienced above average streamflow, while the mid-20th century was characterized by a long dry period. The reconstructed streamflow data series revealed 6-yr (99%), 11-yr (95%) and 17–25-yr (99%) cycles. We suggest that variability in summer streamflow of the Tuoshigan River may be related to solar activity and large-scale oscillations in the climate system. [ABSTRACT FROM AUTHOR]

A correction to the article "Tree-ring-based reconstruction of precipitation in the Changling Mountains, China, since A.D.1691" that was published in the June 1, 2012 issue is presented.

We present a drought reconstruction for southeastern China based on a tree-ring width chronology of Cryptomeria fortunei developed from two sampling sites in central Fujian. A reconstruction of July-February drought variability, spanning AD 1855-2011, was developed by calibrating total tree-ring width data with the self-calibrating Palmer drought severity index (sc PDSI). The reconstruction was verified against an independent data set, and accounts for 36% of the actual sc PDSI variance during the period 1955-2011. Relatively dry intervals were reconstructed between AD 1859-1880, 1899-1911, 1927-1933, 1946-1959, 1964-1970 and 1987-1997. Relatively wet conditions prevailed during 1855-1858, 1881-1898, 1912-1926, 1934-1945, 1960-1963, 1971-1986 and 1998-2011. Comparisons between our scPDSI reconstruction and a moisture-sensitive tree-ring width record from Vietnam revealed consistencies between the two data sets, suggesting similar drought regimes. Spectral peaks of 2.2-6.4 years may be indicative of El Niño-Southern Oscillation ( ENSO) activity, as also suggested by the significant correlations with sea surface temperatures ( SSTs) in the eastern equatorial and southeastern Pacific Ocean and an extreme event analysis. The analysis of links between our sc PDSI reconstruction and the large-scale regional climatic variation shows that there is a relationship between regional drought variation and East Asian summer monsoon (EASM) intensity. [ABSTRACT FROM AUTHOR]

July–June precipitation has been reconstructed to 1756 AD for the western Tien Shan Mountains, Central Asia, using the Picea schrenkiana tree-ring width. The reconstruction explains 31% of the variation in the observed precipitation from 1933 to 2009. Some extremely dry signals in the historical documents are captured precisely in this new reconstruction. Wet periods occurred during the periods of 1811–1828, 1843–1880, 1893–1915, 1929–1934, and 1983–2002, while the periods 1766–1810, 1829–1842, 1881–1892, 1916–1928, and 1935–1982 were relatively dry. Power spectral and wavelet analyses demonstrated the existence of significant 32-, 17-, and 2.6–7.4-year cycles of variability. An assessment of spatial correlation analysis and the significant correlation coefficients between the reconstructed precipitation series and three precipitation reconstructions indicate that our reconstruction might contain multiple large-scale climatic signals in the low-frequency domain. A wetting trend in the eastern Central Asia since the 1970s decades was also captured by this reconstruction. [ABSTRACT FROM AUTHOR]

The great rivers that flow from the southern Tibetan Plateau (TP) affect billions of people in the downstream countries of Asia. Understanding of the hydrological variability of these rivers is still limited, however, because of the lack of long-term streamflow records. Tree-ring width chronologies from six sites are applied to reconstruct annual streamflow of the Salween River, the last remaining large free-flowing transboundary river draining the southern TP, and a critical water source for countries of Southeast Asia. Response function analysis shows that precipitation is the main factor limiting the radial growth of the sampled trees. Linear regression of annual (September–June) Salween River streamflow on the first principal component of tree-ring chronologies explains 53.4% of the streamflow variance, 1958–2011, and yields a reconstruction for the interval 1500–2011 CE. A tally of droughts and wet periods emphasizes the severity of droughts before the start of the gauged records, and a tendency toward wetter conditions in recent decades. Regional temperature is negatively associated with the reconstructed streamflow. Cold wet summers controlled by the Asian summer monsoon are responsible for an increasing trend in streamflow over the last decades. Reconstructed hydrological change is linked to the history of mainland Southeast Asia through the impact of water shortages on Burma society. In particular, prolonged periods of low flow of the Salween River coincide with the falls of the Toungoo Empires and the First Anglo-Burmese War. This tree-ring reconstruction provides a long-term perspective on hydrological changes in the Upper Salween River Basin that can give insight for sustainable water management on the TP and in Myanmar. [ABSTRACT FROM AUTHOR]

Climatic change is exhibiting significant effects on the ecosystem of the Tibetan Plateau (TP), a climate-sensitive area. In particularly, winter frost, freezing events and snow avalanche frequently causing severe effects on ecosystem and social economy, however, few long-term winter temperature records or reconstructions hinder a better understanding on variations in winter temperature in the vast area of the TP. In this paper, we present a minimum winter (November–February) temperature reconstruction for the past 668 years based on a tree-ring network (12 new tree-ring chronologies) on the southeastern TP. The reconstruction exhibits decadal to inter-decadal temperature variability, with cold periods occurring in 1423–1508, 1592–1651, 1729–1768, 1798–1847, 1892–1927, and 1958–1981, and warm periods in 1340–1422, 1509–1570, 1652–1728, 1769–1797, 1848–1891, 1928–1957, and 1982–2007. As suggested by the comparisons with existing winter temperature series and spatial correlations with Climatic Research Unit gridded data, our reconstruction is reliable and indicative, and it can represent large-scale winter temperature variability on the southeastern TP. Furthermore, it shows an overall agreement with winter temperature from the northeastern TP on decadal to inter-decadal timescales. It also shows the possible effects of volcanic eruption and reducing solar activity on the winter temperature variability for the past six centuries on the southeastern TP. [ABSTRACT FROM AUTHOR]

• Tree rings provide streamflow record of Lhasa River since 1546. • Tree ring record provides the context for climate forcing of streamflow variation. • The reconstruction provides a context for assessing past and future regional hydrologic change of Southern Asia. The Lhasa River is the largest tributary of the Yarlung Zangbo River, provides up to 85% of the water supply for the city of Lhasa, and has a high ecologic and economic importance. Annual streamflow of the Lhasa River is reconstructed from Juniperus tibetica tree rings. The streamflow reconstruction developed for the southern Tibetan Plateau goes back to 1546 CE and has a R 2 of 0.485. Spectral and wavelet analysis indicates the existence of decadal (34 and 16 years) and interannual (8.1, 5.7, 4.8, 3.8, 3.5, 3.2, 2.7, 2.3 and 2.1 years) cycles that may reflect climate forcings. Lhasa River streamflow is significantly correlated with precipitation over a vast part of the Yarlung Zangbo River basin, and represents streamflow of the upper Yarlung Zangbo River to a certain extent. Lhasa River variation is linked with large-scale climate circulation features, such as the El Niño-Southern Oscillation (ENSO) and Asian summer monsoon. Some years of abnormally high and low streamflow are related to ENSO events. Based on the reconstruction, the probability that annual streamflow does not exceed a target defined as the instrumental-period mean was lower (48% non-exceedance probability) than during the instrumental period. This study indicates that the instrumental record does not contain the full range of streamflow, especially the lowest streamflow events, and the reconstruction makes up for this shortcoming. Future water resource supply planning based on the instrumental record and streamflow reconstructions will be able to effectively reduce the risks posed by climate change. [ABSTRACT FROM AUTHOR]

Mountain systems are the most important sources of water in arid Central Asia (ACA). It is therefore essential to understand past cycles of droughts and pluvials and to explore how future cycles might influence the sustainable utilization of regional water resources. The Palmer Drought Severity Index (PDSI) is a widely applied measure of dryness that can be reconstructed from tree rings. Here, a Schrenk spruce ( Picea schrenkiana Fisch. et Mey) tree-ring chronology was developed for the Dzungarian Alatau of ACA. Correlation and response analysis indicated that the PDSI from previous July to current June was the principal factor limiting radial growth. The chronology was used to reconstruct the PDSI of the past 189 years for the Dzungarian Alatau. A calibration model for the period from 1950 to 2011 explains 42.6% (or 41.7% after adjusting for the loss of degrees of freedom) of the actual PDSI variance. The reconstructed PDSI might be representative of drought conditions for most of ACA because it captures severe drought events in the 1910s and 1940s that were widespread across ACA. The extreme drought years 1917 and 1945 are especially pronounced. A decadal analysis shows that the five periods in which the PDSI trend increased were 1830–1840s, 1880–1890s, 1920–1930s, 1950–1960s, 1980–2000s. The PDSI declined in the 1850–1870s, the 1900–1910s, the 1940s and the 1970s. The PDSI in ACA exhibited a notably long and rapid wetting from 1980 to 2005, but decreased after 2005. In fact, there have been three especially dry years (2008, 2014 and 2015) in the last 10 years. Meanwhile, there was large power in the 2.1-year, 2.9-year, 4.1-year, 5.5-year, 9.5-year and 10.8-year short periods and in the 30–40-year long periods. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, we developed a tree-ring-width chronology of Schrenk spruce ( Picea schrenkiana Fisch. et Mey) in southern Kazakhstan. Climate-growth response result showed that the precipitation from the previous June to current May was the principal limited factor of radial growth. We also obtained a 246-year reconstruction of June-May precipitation in southern Kazakhstan. The reconstruction explains 39.7% of the variance in precipitation records during the 1902-2013 calibration periods. In addition, the precipitation over the past 246 years in southern Kazakhstan has experienced six wetter periods and seven drier ones, and the extreme drought years were 1837, 1879, 1917 and 1945. From 1985 to 2004, precipitation has experienced longer and more rapid wetting, but the trend of precipitation has decreased in the past few years. The reconstructed series of precipitation is consistent with the historic precipitation/Palmer Drought Severity Index of the western Tianshan Mountains. Here, high precipitation variability occurred during 1770-1800 and 1900-present, while 1800-1900 was relatively calm. Meanwhile, there was large power in the 2- to 7-year short-period and over the 34- to 35- and 40- to 43-year long-periods. We suggest the precipitation variability may be associated with large-scale oscillations in the climate system. The reconstruction sheds new light on precipitation variability and the changes in a region where the climate history over the past several centuries is poorly understood. [ABSTRACT FROM AUTHOR]

We developed a tree-ring width chronology from pine trees ( Pinus tabulaeformis and Pinus armandii) stand near the peaks of Huashan, Shaanxi, north-central China. Growth-climate response analyses showed that the radial growth of pine trees is mainly influenced by April-June precipitation. A model to reconstruct precipitation based on tree widths was constructed, accounting for 55 % of the instrumental variance during the period 1953-2012. Spatial correlation analyses between the reconstruction and observed gridded precipitation data shows that the seasonal precipitation reconstruction captures regional climatic variations over north China. Compared with the historical archives and other tree-ring records in north China, many large-scale drought events, linked to the El Niño-Southern Oscillation (ENSO), were found. Many of these events have had profound impacts on the people of north China over the past several centuries. Composite maps of sea surface temperatures and 500 hPa geopotential heights for selected extremely dry and wet years in Huashan show characteristics similar to those related to the ENSO patterns, particularly with regard to ocean and atmospheric conditions in the equatorial and north Pacific. Our 531-year precipitation reconstruction for Huashan provides a long-term perspective on current and 20th century wet and dry events in north China, and is useful to guide expectations of future variability, and helps us to address climate change. [ABSTRACT FROM AUTHOR]

ABSTRACT A July-May precipitation reconstruction for the period AD 1816-2010 was developed from a tree-ring width chronology of Picea wilsonii for the Xinglong Mountains area of Lanzhou. The reconstruction explains 55.8% of the actual precipitation variance during the calibration period from 1951 to 2010. Wet conditions prevailed during the periods 1822-1835, 1843-1858, 1870-1877, 1884-1891, 1911-1921, 1933-1938, 1944-1979 and 2009-2010. Dry episodes occurred during 1816-1821, 1836-1842, 1859-1869, 1878-1883, 1892-1910, 1922-1932, 1939-1943 and 1980-2008. Multi-taper method spectral analysis indicates the existence of some significant peaks at 2.8, 3.0 and 3.5 years. Spatial correlations with gridded land surface precipitation data revealed that our reconstruction represents regional precipitation signal for a large area of North China linked to the East Asian summer monsoon (EASM). Comparison with other tree-ring-based precipitation/drought reconstructions from surrounding areas implies a high degree of confidence for our reconstruction. Precipitation variations in the study area are significantly correlated with sea surface temperatures in eastern equatorial Pacific Ocean and tropical western Pacific Ocean, suggesting a possible connection of regional precipitation variations to the EASM and the El Niño-Southern Oscillation (ENSO). [ABSTRACT FROM AUTHOR]

Tree-ring based precipitation/PDSI series from six sites were applied to reconstruct the regional precipitation (dry/wet) index for the west-central Tianshan Mountains for the last 300 years. The analysis of the reconstructed index series indicates that the dry and wet years in the whole time period were almost equal in frequencies. The results show that the 300-year period is characterized by a series of dry/wet stages, including six dry stages (1707–1719, 1768–1782, 1822–1832, 1880–1886, 1913–1924 and 1973–1989) and five wet stages (1723–1741, 1843–1857, 1893–1907, 1933–1940 and after-1990 period). The reconstructed regional precipitation (dry/wet) series also exhibits quasi-periodicities of 2–5 y, 7–8 y, 11 y, 30 y, 50 y and 80 y, with the 11 y, 30 y and 50 y quasi-periodicities being more significant. Shifts from dry to wet climate occurred in 1720, 1779 and 1886, and the shifts from wet to dry climate occurred in 1741, 1854 and 1904. In addition, the analysis also indicates that solar activities might have significantly affected the regional precipitation (dry/wet) variability on ∼10 y scale during 1770s–2000s. The effects of solar activities on annual precipitation in the Tianshan Mountains are more complicated than expected, and the complexity might be associated with a number of unknown processes. [ABSTRACT FROM AUTHOR]

In the original publication of the article Fig. 1 was incorrect. The correct Fig. 1 is given below. [ABSTRACT FROM AUTHOR]

Presents a study on the climatic changes in the Yili region of Xinjiang, China. Details on the study site and method; Information on the Heinrich-rhythm pulses in the Zeketai loess section; Conclusions.