Snow/rainfall anomaly in winter of northern China and associated atmospheric circulation and aerosol distribution features

2011 ◽  
Vol 25 (6) ◽  
pp. 783-796 ◽  
Author(s):  
Duo Li ◽  
Jizhi Wang ◽  
Zechun Li ◽  
Hua Liu
Keyword(s):  
Atmospheric Circulation ◽  
Northern China ◽  
Rainfall Anomaly ◽  
Aerosol Distribution ◽  
Distribution Features

scholarly journals Temporal Variability of Drought in Nine Agricultural Regions of China and the Influence of Atmospheric Circulation

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 990
Author(s):  
Haowei Sun ◽  
Haiying Hu ◽  
Zhaoli Wang ◽  
Chengguang Lai
Keyword(s):  
Atmospheric Circulation ◽  
Southern China ◽  
Northern China ◽  
Chinese Mainland ◽  
Subtropical High ◽  
Trade Wind ◽  
Severe Drought ◽  
The Chinese Mainland ◽  
Agricultural Regions ◽  
The Impact

In recent decades, the severe drought across agricultural regions of China has had significant impact on agriculture. The standardized precipitation evapotranspiration index (SPEI) has been widely used for drought analyses; however, SPEI is prone to be affected by potential evapotranspiration (PET). We thus examined the correlations between soil moisture anomalies and the SPEI calculated by the Thornthwaite, Hargreaves, and Penman–Monteith (PM) equations to select the most suitable for drought research. Additionally, the Mann–Kendall and wavelet analysis were used to investigate drought trends and to analyze and the impact of atmospheric circulation on drought in China from 1961 to 2018. The results showed that (1) PET obtained from the PM equation is the most suitable for SPEI calculation; (2) there were significant wetting trends in Northern China and the whole Chinese mainland and most of the wetting mutation points occurred in the 1970s and 1980s and the significant inter-annual oscillations period in the Chinese mainland was 2–4 years; (3) the Chinese mainland and Northern China are strongly influenced by West Pacific Trade Wind, while Western Pacific Subtropical High Intensity and Pacific Subtropical High Area have primary impact on Southern China.

The impact of large-scale atmospheric patterns on Heatwaves in summer Northern China based on Self-Organizing Map

2020 ◽  
Author(s):  
Chen Shi ◽  
Wang Kaicun ◽  
Zhou Chunlüe
Keyword(s):  
Atmospheric Circulation ◽  
Large Scale ◽  
Stepwise Regression ◽  
Northern China ◽  
Subtropical High ◽  
Self Organizing Map ◽  
Okhotsk Sea ◽  
Circulation Patterns ◽  
The Impact ◽  
Self Organizing

<p>Heatwave is affected by large-scale atmospheric circulation on temperature-related climates in the context of global warming. Recently Northern China have experienced an increase in heatwaves which is partly due to the atmospheric circulation. This study aims to address the influence clearly. Northern China heatwaves are computed on excess hot factor (EHF) and the five EHF indexes are studied afterwards to get a picture of heatwaves in summer Northern China. China circulation patterns are classified into nine typical circulation patterns on self-organizing map (SOM) which then can be described quantitatively by pattern factors: frequency, persistence and maximum persistence. Pearson correlation analysis and stepwise regression analysis are applied for exploring the impact. Results show the spatial pattern of the times of individual heatwave event (HWN) and the days of the longest heatwave duration (HWD) are high value everywhere in Northern China. The overall EHF indexes all rising in time series (P<0.05) and the regional heatwave occurrence have trends of 0.79 day per year (P<0.05). However, the factors of the patterns show inconspicuous tendency. Two patterns with significant correlations (P<0.05) are proved to be suggestive of Okhotsk Sea high and West Pacific Subtropical High. It declares that the Okhotsk Sea high favors Northern China heatwave occurrence rather than subtropical high: the warm center over Okhotsk Sea transfer heat upper and west, generating the high temperature and persist high pressure system, causing heatwave happening in summer Northern China. The two related atmospheric circulation patterns explain 38% of the heatwave occurrence based on stepwise regression model, the Okhotsk Sea high gets the coefficient of 0.443 and the subtropical high is -0.347.  </p>

scholarly journals Possible influence of atmospheric circulations on winter haze pollution in the Beijing–Tianjin–Hebei region, northern China

2016 ◽  
Vol 16 (2) ◽  
pp. 561-571 ◽  
Author(s):  
Z. Zhang ◽  
X. Zhang ◽  
D. Gong ◽  
S.-J. Kim ◽  
R. Mao ◽  
...  
Keyword(s):  
Sea Level ◽  
Atmospheric Circulation ◽  
Correlation Coefficients ◽  
Northern China ◽  
Reanalysis Data ◽  
Atmospheric Circulations ◽  
Boundary Layer Height ◽  
Haze Pollution ◽  
Atmospheric Circulation Indices ◽  
Circulation Indices

Abstract. Using the daily records derived from the synoptic weather stations and the NCEP/NCAR and ERA-Interim reanalysis data, the variability of the winter haze pollution (indicated by the mean visibility and number of hazy days) in the Beijing–Tianjin–Hebei (BTH) region during the period 1981 to 2015 and its relationship with the atmospheric circulations at middle–high latitude were analyzed in this study. The winter haze pollution in BTH had distinct inter-annual and inter-decadal variabilities without a significant long-term trend. According to the spatial distribution of correlation coefficients, six atmospheric circulation indices (I1 to I6) were defined from the key areas in sea level pressure (SLP), zonal and meridional winds at 850 hPa (U850, V850), geopotential height field at 500 hPa (H500), zonal wind at 200 hPa (U200), and air temperature at 200 hPa (T200), respectively. All of the six indices have significant and stable correlations with the winter visibility and number of hazy days in BTH. In the raw (unfiltered) correlations, the correlation coefficients between the six indices and the winter visibility (number of hazy days) varied from 0.57 (0.47) to 0.76 (0.6) with an average of 0.65 (0.54); in the high-frequency ( < 10 years) correlations, the coefficients varied from 0.62 (0.58) to 0.8 (0.69) with an average of 0.69 (0.64). The six circulation indices together can explain 77.7 % (78.7 %) and 61.7 % (69.1 %) variances of the winter visibility and the number of hazy days in the year-to-year (inter-annual) variability, respectively. The increase in Ic (a comprehensive index derived from the six individual circulation indices) can cause a shallowing of the East Asian trough at the middle troposphere and a weakening of the Siberian high-pressure field at sea level, and is then accompanied by a reduction (increase) of horizontal advection and vertical convection (relative humidity) in the lowest troposphere and a reduced boundary layer height in BTH and its neighboring areas, which are favorable for the formation of haze pollution in BTH winter, and vice versa. The high level of the prediction statistics and the reasonable mechanism suggested that the winter haze pollution in BTH can be forecasted or estimated credibly based on the optimized atmospheric circulation indices. Thus it is helpful for government decision-making departments to take action in advance in dealing with probably severe haze pollution in BTH indicated by the atmospheric circulation conditions.

A transient simulation of precession-scale spring dust activity over northern China and its relation to mid-latitude atmospheric circulation

2020 ◽  
Vol 542 ◽  
pp. 109585
Author(s):  
Xinzhou Li ◽  
Xiaodong Liu ◽  
Zaitao Pan ◽  
Zhengguo Shi ◽  
Xiaoning Xie ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Northern China ◽  
Transient Simulation ◽  
Spring Dust

Hail Day Frequency Trends and Associated Atmospheric Circulation Patterns over China during 1960–2012

2016 ◽  
Vol 29 (19) ◽  
pp. 7027-7044 ◽  
Author(s):  
Mingxin Li ◽  
Qinghong Zhang ◽  
Fuqing Zhang
Keyword(s):  
Tibetan Plateau ◽  
Atmospheric Circulation ◽  
Southern China ◽  
East Asian ◽  
Northern China ◽  
The Tibetan Plateau ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
Change In Mean

Abstract Based on a comprehensive collection of hail observations and the NCEP–NCAR reanalyses from 1960 to 2012, the long-term trends of hail day frequency in mainland China and the associated changes in atmospheric circulation patterns were analyzed. There was no detectable trend in hail frequency from 1960 to the early 1980s, but a significant decreasing trend was apparent in later periods throughout most of China and in particular over the Tibetan Plateau from the early 1980s and over northern and northwestern China from the early 1990s. Hail frequency in southern China did not decrease as significantly as in other regions over the last couple of decades. An objective classification method, the obliquely rotated T-mode principal component technique, was used to investigate atmospheric circulation patterns. It was found that 51.85% of the hail days occurred during two major circulation types, both of which were associated with cold frontal systems in northern China. More specifically, the synoptic trough in East Asia, signified by the meridional circulation at 850 hPa, became considerably weaker after 1990. This change in the synoptic pattern is consistent with a weakening trend in the East Asian summer monsoon, the primary dynamic forcing of moisture transport that contributes to the generation of severe convection in northern China. The long-term variability of hail day frequency over the Tibetan Plateau was more strongly correlated with the change in mean freezing-level height (FLH) than the strength of the East Asian monsoon.

scholarly journals Measurement of 10Be Concentration of Modern Falling Dust in Northern China

Radiocarbon ◽  
2012 ◽  
Vol 54 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Feng Xian ◽  
Weijian Zhou ◽  
Xianghui Kong ◽  
Jun Jiang ◽  
Zhenkun Wu ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Temporal Distribution ◽  
Northern China ◽  
Sediment Concentration ◽  
Mean Value ◽  
Chinese Loess ◽  
10Be Concentration ◽  
Dust Flux ◽  
Fundamental Information ◽  
Distribution Features

Paleoenvironmental and paleogeomagnetic tracing studies from Chinese loess 10Be have progressed in recent years (Zhou et al. 2007a,b, 2010). In this approach, 10Be flux determined from sediment concentration and accumulation rate may be used to recover information about paleomonsoon rainfall rates as well as past variations in the geomagnetic field strength. However, these methods require that a correction be made for residual undecayed 10Be in remobilized dust. To better understand the feature of the 10Be signals related to the remobilized dust, we report the first observational study on 10Be concentration of modern falling dust using the 3MV multi-element accelerator mass spectrometer (AMS) in the Xi'an AMS Center. Ten samples collected at Ansai observation station (109°19′E, 36°51′N) in northern China from May 2008 to June 2009 are measured along with 3 chemical blanks. The results clearly show that the 10Be content of modern falling dust is relatively uniform, with a mean value of 1.21 x 108 atoms/g, a measurement similar to that of Chinese loess (Zhou et al. 2007a) and to the value found in the study by Shen et al. (2009) on dust 10Be falling near Dingbian, China (1.25 ± 0.06 x 108 atoms/g). Despite the fact that modern dust flux is much higher in spring relative to summer in northern China, 10Be concentration in falling dust remains fairly constant. In addition, we find that dust 10Be concentration is roughly independent of the local precipitation changes. This feature might be considered as an analogue to improve our understanding on the fundamental information of the source component contained in loess 10Be records and its spatial/temporal distribution features.

scholarly journals Measurement of 10Be Concentration of Modern Falling Dust in Northern China

Radiocarbon ◽  
2012 ◽  
Vol 54 (01) ◽  
pp. 37-43
Author(s):  
Feng Xian ◽  
Weijian Zhou ◽  
Xianghui Kong ◽  
Jun Jiang ◽  
Zhenkun Wu ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Temporal Distribution ◽  
Northern China ◽  
Sediment Concentration ◽  
Mean Value ◽  
Chinese Loess ◽  
10Be Concentration ◽  
Dust Flux ◽  
Fundamental Information ◽  
Distribution Features

Paleoenvironmental and paleogeomagnetic tracing studies from Chinese loess10Be have progressed in recent years (Zhou et al. 2007a,b, 2010). In this approach,10Be flux determined from sediment concentration and accumulation rate may be used to recover information about paleomonsoon rainfall rates as well as past variations in the geomagnetic field strength. However, these methods require that a correction be made for residual undecayed10Be in remobilized dust. To better understand the feature of the10Be signals related to the remobilized dust, we report the first observational study on10Be concentration of modern falling dust using the 3MV multi-element accelerator mass spectrometer (AMS) in the Xi'an AMS Center. Ten samples collected at Ansai observation station (109°19′E, 36°51′N) in northern China from May 2008 to June 2009 are measured along with 3 chemical blanks. The results clearly show that the10Be content of modern falling dust is relatively uniform, with a mean value of 1.21 x 108atoms/g, a measurement similar to that of Chinese loess (Zhou et al. 2007a) and to the value found in the study by Shen et al. (2009) on dust10Be falling near Dingbian, China (1.25 ± 0.06 x 108atoms/g). Despite the fact that modern dust flux is much higher in spring relative to summer in northern China,10Be concentration in falling dust remains fairly constant. In addition, we find that dust10Be concentration is roughly independent of the local precipitation changes. This feature might be considered as an analogue to improve our understanding on the fundamental information of the source component contained in loess10Be records and its spatial/temporal distribution features.

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