April–June precipitation reconstruction for Xi'an and drought assessment for the Guanzhong Plain from tree rings of Chinese pine

2014 ◽  
Vol 6 (3) ◽  
pp. 638-646 ◽  
Author(s):  
Feng Chen ◽  
Yujiang Yuan ◽  
Wenshou Wei ◽  
Ziang Fan ◽  
Ruibo Zhang ◽  
...  
Keyword(s):  
Southern Oscillation ◽  
Asian Summer Monsoon ◽  
Summer Precipitation ◽  
Northern China ◽  
Early Summer ◽  
Shaanxi Province ◽  
Precipitation Reconstruction ◽  
Chinese Pine ◽  
Drought Assessment ◽  
Tree Growth Model

Variations in earlywood width (EWW) of Chinese pine in the Nanwutai Mountain were used to develop high-resolution climate proxy data to extend existing climate records in Guanzhong Plain, Shaanxi Province, China. Growth–climate response analyses showed the EWW series in Nanwutai Mountain are mainly influenced by spring and early summer precipitation. Based on the EWW series derived from the Nanwutai Mountain, we developed an April–June precipitation reconstruction for Xi'an for the period 1800–2009. The climate/tree-growth model accounts for 36.4% of the instrumental precipitation variance during the period 1951–2009. Spatial climate correlation analyses with the gridded precipitation data revealed that our precipitation reconstruction contains a strong regional precipitation signal for the Guanzhong Plain. Our reconstruction successfully captured recent climatic changes and agreed, in general, with other tree-ring-based precipitation reconstructions from nearby regions on a decadal timescale. The rainfall/drought series in northern China also showed highly synchronous decreasing trends since the 1970s, suggesting that precipitation related to the East Asian summer monsoon has decreased by large spatial and temporal (decadal) scales. In addition, wavelet analysis revealed the existence of some decadal (13.3-year) and interannual (9.1-, 5.4-, 3.1-, and 2.1-year) cycles, which may potentially be the fingerprints of some proposed climate change forcings, such as El Niño-Southern Oscillation and solar activities.

scholarly journals Relative impact of insolation and Warm Pool surface temperature on the East Asia Summer Monsoon during the MIS-13 interglacial

2014 ◽  
Vol 10 (2) ◽  
pp. 1025-1051 ◽  
Author(s):  
Q. Z. Yin ◽  
U. K. Singh ◽  
A. Berger ◽  
Z. T. Guo ◽  
M. Crucifix
Keyword(s):  
Surface Temperature ◽  
Summer Monsoon ◽  
Climate Modeling ◽  
Southern China ◽  
Asian Summer Monsoon ◽  
Summer Precipitation ◽  
Northern China ◽  
Warm Pool ◽  
Pool Surface ◽  
The Impact

Abstract. During Marine Isotope Stage (MIS) 13, an interglacial about 500 000 years ago, the East Asian summer monsoon (EASM) was suggested exceptionally strong by different proxies in China. However, MIS-13 is a weak interglacial in marine oxygen isotope records and has relatively low CO2 and CH4 concentrations compared to other interglacials of the last 800 000 years. In the mean time, the sea surface temperature (SST) reconstructions show that the Western Pacific Warm Pool was relatively warm during MIS-13. Based on climate modeling experiments, this study aims at investigating whether this Warm Pool warming could explain the exceptionally strong EASM occurring during the relatively cool interglacial MIS-13. The individual contributions of insolation and of the Warm Pool SST as well as their synergism are quantified through experiments with the Hadley Centre atmosphere model, HadAM3 and using the factor separation technique. The SST over the Warm Pool region has been increased based on geological reconstructions. Our results show that the pure impact of a strong summer insolation contributes to strengthen significantly the summer precipitation in northern China but only little in southern China. The pure impact of enhanced Warm Pool SST reduces, slightly, the summer precipitation in both northern and southern China. However, the synergism between insolation and enhanced Warm Pool SST contributes to a large increase of summer precipitation in southern China but to a decrease in northern China. Therefore, the ultimate role of enhanced Warm Pool SST reinforces the impact of insolation in southern China but reduces its impact in northern China. We conclude that enhanced SST over the Warm Pool region does help to explain the strong MIS-13 EASM precipitation in southern China as recorded in proxy data, but other explanation is needed for explaining the exceptionally strong EASM in northern China.

Interdecadal Change in the Relationship between ENSO and the Intraseasonal Oscillation in East Asia

2010 ◽  
Vol 23 (13) ◽  
pp. 3599-3612 ◽  
Author(s):  
Kyung-Sook Yun ◽  
Kyong-Hwan Seo ◽  
Kyung-Ja Ha
Keyword(s):  
Indian Ocean ◽  
North Pacific ◽  
Southern Oscillation ◽  
Asian Summer Monsoon ◽  
Intraseasonal Oscillation ◽  
Longwave Radiation ◽  
Strong Relationship ◽  
Early Summer ◽  
Boreal Summer ◽  
Interdecadal Change

Abstract The northward-propagating intraseasonal oscillation (NPISO) during the boreal summer is closely linked to the onset/retreat and intensity of the East Asian summer monsoon (EASM). In this study, interdecadal variability in the relationships between the NPISO and El Niño–Southern Oscillation (ENSO) was investigated using long-term outgoing longwave radiation data obtained from the 40-yr ECMWF Re-Analysis (ERA-40) for a 44-yr period (1958 to 2001). It was found that before the late 1970s, the preceding winter ENSO influenced the early summer (i.e., May to June) NPISO activity, whereas after the late 1970s a strong relationship appeared during the later summertime (i.e., July to August). The May–June NPISO before the late 1970s was modulated by springtime Indian Ocean sea surface temperature warming and central North Pacific suppressed convection anomalies and was consequently related to the ENSO-induced west Pacific (WP) pattern, which shows a north–south dipole structure over the North Pacific from winter through spring. After the late 1970s, because of an anomalously strengthened Walker–Hadley circulation, Indian Ocean SST warming was significantly maintained until summer, which promoted a strong suppressed convection anomaly over the Philippine Sea during summer and consequently an enhanced western North Pacific subtropical high and Pacific–Japan (PJ) pattern.

Dendroclimatology of high-elevation Nothofagus pumilio forests at their northern distribution limit in the central Andes of Chile

2001 ◽  
Vol 31 (6) ◽  
pp. 925-936 ◽  
Author(s):  
Antonio Lara ◽  
Juan Carlos Aravena ◽  
Ricardo Villalba ◽  
Alexia Wolodarsky-Franke ◽  
Brian Luckman ◽  
...  
Keyword(s):  
Tree Ring ◽  
Radial Growth ◽  
Summer Precipitation ◽  
Central Andes ◽  
Early Summer ◽  
Late Spring ◽  
Tree Line ◽  
Nothofagus Pumilio ◽  
Precipitation Reconstruction ◽  
Climate Signal

Nothofagus pumilio (Poepp et Endl.) Krasser, is a deciduous tree species that grows in Chile and adjacent Argentina between 36 and 56°S, often forming the Andean tree line. This paper presents the first eight tree-ring chronologies from N. pumilio at its northern range limit in the central Andes of Chile (36–39°S) and the first precipitation reconstruction for this region. Samples were taken from upper tree-line stands (1500–1700 m elevation) in three study areas: Vilches, Laguna del Laja, and Conguillío. Results indicate that, at the northern sites (Vilches and Laguna del Laja), the tree-ring growth of N. pumilio is positively correlated with late-spring and early summer precipitation and that higher temperatures reduce radial growth, probably because of an increase in evapotranspiration and decrease in water availability. At the southern Conguillío study area, radial growth was negatively correlated with late-spring and early summer precipitation. The presence of volcanic activity in this latter study area, which might have masked the climate signal, did not seem to have a significant influence on radial growth. A reconstruction of November–December (summer) precipitation for the period 1837–1996 from N. pumilio tree-ring chronologies accounted for 37% of instrumentally recorded precipitation variance. This is the first precipitation reconstruction from N. pumilio chronologies. Only temperature and snow cover have previously been reconstructed using this species. The reconstruction indicates that the driest and wettest 25-year periods within the past 160 years are 1890–1914 and 1917–1941, respectively.

scholarly journals Summer precipitation reconstructed quantitatively using a Mid Holocene δ<sup>13</sup>C common millet record from Guanzhong Basin, China

2016 ◽  
Author(s):  
Qing Yang ◽  
Xiaoqiang Li ◽  
Xinying Zhou ◽  
Keliang Zhao ◽  
Nan Sun
Keyword(s):  
Robust Regression ◽  
Asian Summer Monsoon ◽  
Summer Precipitation ◽  
Regression Function ◽  
Growing Season ◽  
Northern China ◽  
Panicum Miliaceum ◽  
Precipitation Record ◽  
Asian Summer ◽  
Guanzhong Basin

Abstract. In order to produce quantitative Holocene precipitation reconstructions for particular geographical areas, explicit proxies and accurate dating controls are required. The fossilized seeds of common millet (Panicum miliaceum) are found throughout the sedimentary strata of northern China, and are highly suited to the production of accurate quantitative Holocene precipitation reconstructions: their isotopic carbon composition (δ13C) gives a measure of the precipitation required during the growing season, and allows these seeds to be dated. We therefore used a robust regression function, as part of a systematic study of the δ13C of common millet, to produce a quantitative reconstruction of Mid Holocene summer precipitation in the Guanzhong Basin. Our results showed that summer precipitation from 7.7–3.4 ka BP was 240–477 mm, with a mean of 354 mm, i.e. ~ 50 mm or 17 % higher than present levels. Maximal mean summer precipitation peaked at 414 mm, ~ 109 mm (or 36 %) higher than today, occurring during 6.4–5.5 ka BP; this is when the East Asian Summer Monsoon (EASM) was at its peak. As the δ13C-based precipitation record can reliably indicate EASM intensity during the Holocene, this work can provide a reliable proxy for further research into the detailed processes, and precise mechanisms, of the EASM.

scholarly journals Anthropogenic forcing of shift in precipitation in Eastern China in late 1970s

2013 ◽  
Vol 13 (5) ◽  
pp. 11997-12032 ◽  
Author(s):  
T. Wang ◽  
H. J. Wang ◽  
O. H. Otterå ◽  
Y. Q. Gao ◽  
L. L. Suo ◽  
...  
Keyword(s):  
East Asian Summer Monsoon ◽  
Yangtze River ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Eastern China ◽  
Summer Precipitation ◽  
Northern China ◽  
Yangtze River Valley ◽  
Interdecadal Shift ◽  
Asian Summer

Abstract. Observation shows that eastern China has experienced an interdecadal shift in the summer precipitation during the second half of the 20th century. The summer precipitation increased in the middle and lower reaches of the Yangtze River Valley, whereas it decreased in northern China. Here we use a coupled ocean–atmosphere general circulation model and multi-ensemble simulations to show that the interdecadal shift is mainly caused by the combined effect of increasing global greenhouse gases and regional aerosol emissions over China. The rapidly increasing greenhouse gases induce tropical warming and a westward shift of the western Pacific subtropical high, leading to more precipitation in Yangtze River Valley. At the same time the aerosol cooling effect over land contributes to a reduced summer land–sea thermal contrast and therefore to a weakened East Asian summer monsoon and to drought in northern China. Consequently, an anomalous precipitation pattern starts to emerge in eastern China in late 1970s. Our results highlight the important role of anthropogenic forcing agents in shaping the weakened East Asian summer monsoon and associated anomalous precipitation in eastern China.

scholarly journals Relative impact of insolation and the Indo-Pacific warm pool surface temperature on the East Asia summer monsoon during the MIS-13 interglacial

2014 ◽  
Vol 10 (5) ◽  
pp. 1645-1657 ◽  
Author(s):  
Q. Z. Yin ◽  
U. K. Singh ◽  
A. Berger ◽  
Z. T. Guo ◽  
M. Crucifix
Keyword(s):  
Surface Temperature ◽  
Summer Monsoon ◽  
Climate Modeling ◽  
Southern China ◽  
Asian Summer Monsoon ◽  
Summer Precipitation ◽  
Northern China ◽  
Warm Pool ◽  
Pacific Warm Pool ◽  
The Impact

Abstract. During Marine Isotope Stage (MIS)-13, an interglacial about 500 000 years ago, the East Asian summer monsoon (EASM) was suggested exceptionally strong by different proxies in China. However, MIS-13 is a weak interglacial in marine oxygen isotope records and has relatively low CO2 and CH4 concentrations compared to other interglacials of the last 800 000 years. In the meantime, the sea surface temperature (SST) reconstructions have shown that the warm pool was relatively warm during MIS-13. Based on climate modeling experiments, this study aims at investigating whether a warmer Indo-Pacific warm pool (IPWP) can explain the exceptionally strong EASM occurring during the relatively cool interglacial MIS-13. The relative contributions of insolation and of the IPWP SST as well as their synergism are quantified through experiments with the Hadley Centre atmosphere model, HadAM3, and using the factor separation technique. The SST of the IPWP has been increased based on geological reconstructions. Our results show that the pure impact of a strong summer insolation contributes to strengthen significantly the summer precipitation in northern China but only little in southern China. The pure impact of enhanced IPWP SST reduces, slightly, the summer precipitation in both northern and southern China. However, the synergism between insolation and enhanced IPWP SST contributes to a large increase of summer precipitation in southern China but to a slight decrease in northern China. Therefore, the ultimate role of enhanced IPWP SST is to reinforce the impact of insolation in southern China but reduce its impact in northern China. We conclude that a warmer IPWP helps to explain the strong MIS-13 EASM precipitation in southern China as recorded in proxy data, but another explanation is needed for northern China.

Interannual Variation of the Spring and Summer Precipitation over the Three River Source Region in China and the Associated Regimes

2018 ◽  
Vol 31 (18) ◽  
pp. 7441-7457 ◽  
Author(s):  
Bo Sun ◽  
Huijun Wang
Keyword(s):  
Interannual Variability ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Asian Summer Monsoon ◽  
Wave Train ◽  
Summer Precipitation ◽  
Interdecadal Variability ◽  
Water Vapor Transport ◽  
Spring Precipitation

This study analyzes the interannual and interdecadal variability of spring and summer precipitation over the Three River Source (TRS) region in China using four datasets. A general consistency is revealed among the four datasets with regard to the interannual and interdecadal variability of TRS precipitation during 1979–2015, demonstrating a confidence of the four datasets in representing the precipitation variability over the TRS region. The TRS spring and summer precipitation shows distinct interannual and interdecadal variability, with an overall increasing trend in the spring precipitation and an interdecadal oscillation in the summer precipitation. The regimes associated with the interannual variability of TRS spring and summer precipitation are further investigated. The interannual variability of TRS spring precipitation is essentially modulated by an anomalous easterly water vapor transport (WVT) branch associated with the leading mode of Eurasian spring circulation. El Niño–Southern Oscillation (ENSO) may affect the interannual variability of TRS spring precipitation by causing southerly WVT anomalies toward the TRS region. The interannual variability of TRS summer precipitation is essentially modulated by an anomalous southwesterly WVT branch over the TRS region, which is mainly associated with a Eurasian wave train connected with the summer North Atlantic Oscillation. A strong East Asian summer monsoon and an El Niño–decaying summer may also contribute to the southwesterly WVT anomalies over the TRS region.

scholarly journals Quantitative reconstruction of summer precipitation using a mid-Holocene <i>δ</i><sup>13</sup>C common millet record from Guanzhong Basin, northern China

2016 ◽  
Vol 12 (12) ◽  
pp. 2229-2240 ◽  
Author(s):  
Qing Yang ◽  
Xiaoqiang Li ◽  
Xinying Zhou ◽  
Keliang Zhao ◽  
Nan Sun
Keyword(s):  
Asian Summer Monsoon ◽  
Summer Precipitation ◽  
Regression Function ◽  
Growing Season ◽  
Northern China ◽  
Panicum Miliaceum ◽  
Quantitative Reconstruction ◽  
Asian Summer ◽  
Guanzhong Basin ◽  
Early Human

Abstract. To quantitatively reconstruct Holocene precipitation for particular geographical areas, suitable proxies and faithful dating controls are required. The fossilized seeds of common millet (Panicum miliaceum) are found throughout the sedimentary strata of northern China and are suited to the production of quantitative Holocene precipitation reconstructions: their isotopic carbon composition (δ13C) gives a measure of the precipitation required during the growing season of summer (here the interval from mid-June to September) and allows these seeds to be dated. We therefore used a regression function, as part of a systematic study of the δ13C of common millet, to produce a quantitative reconstruction of mid-Holocene summer precipitation in the Guanzhong Basin (107°40′–107°49′ E, 33°39′–34°45′ N). Our results showed that mean summer precipitation at 7.7–3.4 ka BP was 353 mm,  ∼  50 mm or 17 % higher than present levels, and the variability increased, especially after 5.2 ka BP. Maximum mean summer precipitation peaked at 414 mm during the period 6.1–5.5 ka BP,  ∼  109 mm (or 36 %) higher than today, indicating that the East Asian summer monsoon (EASM) peaked at this time. This work can provide a new proxy for further research into continuous paleoprecipitation sequences and the variability of summer precipitation, which will promote the further research into the relation between early human activity and environmental change.

scholarly journals Spatial and seasonal variability of PM<sub>2.5</sub> acidity at two Chinese megacities: insights into the formation of secondary inorganic aerosols

2011 ◽  
Vol 11 (9) ◽  
pp. 25557-25603 ◽  
Author(s):  
K. He ◽  
Q. Zhao ◽  
Y. Ma ◽  
F. Duan ◽  
F. Yang
Keyword(s):  
Atmospheric Chemistry ◽  
Asian Summer Monsoon ◽  
Northern China ◽  
Early Summer ◽  
Heterogeneous Reactions ◽  
Central China ◽  
Northwestern Pacific ◽  
Annual Variations ◽  
Aerosol Acidity ◽  
Spatial And Seasonal Variation

Abstract. Aerosol acidity is one of the most important parameters influencing atmospheric chemistry and physics. Based on continuous field observation from January 2005 to May 2006, both spatial and seasonal variation in PM2.5 acidity was investigated at Beijing and Chongqing, two megacities in northern and southwestern China, respectively. PM2.5 was generally more acidic at urban and rural sites in Chongqing than Beijing, but a reverse spatial pattern was found within the two cities, with more acidic PM2.5 at urban Beijing and rural Chongqing comparing to their rural and urban sites, respectively. PM2.5 was more acidic in summer and fall than in winter, while large inter-annual variations were evident during the springs of 2005 and 2006, with Beijing and Chongqing exhibiting opposite trends, however. The higher acidity of PM2.5 in the spring of 2006 in Beijing was attributed to the influence of Asian desert dust which significantly enhanced the formation of nitrate relative to sulfate; in contrast, the more acidic aerosols found during the spring of 2005 in Chongqing was mainly due to the greater wet deposition of ammonium, and precipitation was probably one of the key factors that controlled the partition of ammonium in PM2.5 and rain water over the surrounding region. Meanwhile, PM2.5 became more acidic at both cities from spring into early summer of 2005. The synoptic-scale evolution of its acidity was found to be closely associated with the greater contribution of air masses from between the Northern China Plain to the south of Beijing, and from central China to the east of Chongqing, and was ended by the northward movement of a subtropical high over the northwestern Pacific, a major element of the Asian summer monsoon. Under conditions of high aerosol acidity, heterogeneous reactions may become one of the major pathways for the formation of nitrate at both cities. These findings may also explain the significant variation in inter-annual aerosol acidity observed during other seasons at Beijing, Chongqing and many other cities in China, as reported in previous studies.

scholarly journals Simulation study on the indirect effect of sulfate on the summer climate over the eastern China monsoon region

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dongdong Wang ◽  
Bin Zhu ◽  
Hongbo Wang ◽  
Li Sun
Keyword(s):  
Radiative Forcing ◽  
Asian Summer Monsoon ◽  
Cloud Condensation Nuclei ◽  
Eastern China ◽  
Summer Precipitation ◽  
Cloud Droplet ◽  
Monsoon Region ◽  
Liquid Water Path ◽  
Surface Cooling ◽  
Community Atmosphere Model

AbstractIn this study, we designed a sensitivity test using the half number concentration of sulfate in the nucleation calculation process to study the aerosol-cloud interaction (ACI) of sulfate on clouds, precipitation, and monsoon intensity in the summer over the eastern China monsoon region (ECMR) with the National Center for Atmospheric Research Community Atmosphere Model version 5. Numerical experiments show that the ACI of sulfate led to an approximately 30% and 34% increase in the cloud condensation nuclei and cloud droplet number concentrations, respectively. Cloud droplet effective radius below 850 hPa decreased by approximately 4% in the southern ECMR, while the total liquid water path increased by 11%. The change in the indirect radiative forcing due to sulfate at the top of the atmosphere in the ECMR during summer was − 3.74 W·m−2. The decreased radiative forcing caused a surface cooling of 0.32 K and atmospheric cooling of approximately 0.3 K, as well as a 0.17 hPa increase in sea level pressure. These changes decreased the thermal difference between the land and sea and the gradient of the sea-land pressure, leading to a weakening in the East Asian summer monsoon (EASM) and a decrease in the total precipitation rate in the southern ECMR. The cloud lifetime effect has a relatively weaker contribution to summer precipitation, which is dominated by convection. The results show that the ACI of sulfate was one possible reason for the weakening of the EASM in the late 1970s.

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