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 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.

scholarly journals The Challenges and Strategies of Food Security under Rapid Urbanization in China

2019 ◽  
Vol 11 (2) ◽  
pp. 542 ◽  
Author(s):  
Yong-sheng Wang
Keyword(s):  
Food Security ◽  
Food Consumption ◽  
Urban Areas ◽  
Southern China ◽  
Northern China ◽  
Northern Region ◽  
Grain Production ◽  
Rapid Urbanization ◽  
Agricultural Income ◽  
The Impact

Food security has received wide attention in China for a long time due to the challenges of a huge population and limited farmland area. Under conditions of rapid urbanization, the food scenario has changed, creating major challenges for massive populations in China. This paper intends to reveal the impact of urbanization on food security and to propose strategies for mitigating the threats to it. Total grain production has continuously increased, but most of the grain production has been distributed in the northern region since 2006. Although the per capita rural income has increased significantly since 1980, the agricultural income ratio has consistently declined from 56.13% in 1983 to 26.61% in 2012. A dramatic shift in food consumption away from grain towards meat, poultry, eggs, milk and liquor has been found in both rural and urban areas. The faster agricultural water consumption growth in northern China over southern China helped close the gap. There has been net increase of cultivated land in northern China, whereas southern China has seen a net decrease. The medium- and low-level cultivation ratios of land were 52.84% and 17.69%, respectively, in 2015. This paper concluded that food security in China could be ensured by increasing production and optimizing consumption. It suggested that enhanced grain production capacity, strict water management, and land consolidation engineering as well as agricultural industrialization could be used for maintaining grain production. Food consumption itself can be managed by optimizing resident dietary pattern, reducing food waste, adjusting grain consumption structure and moderating food imports policy.

Semi-Orthodox Prose Poetry

2016 ◽  
Author(s):  
Nick Admussen
Keyword(s):  
Hong Kong ◽  
Chinese Mainland ◽  
Social Philosophy ◽  
Prose Poetry ◽  
Close Reading ◽  
The World ◽  
The Chinese Mainland ◽  
The Aesthetic ◽  
The Impact

Chapter four is a close reading of Liu Zaifu, a poet, scholar and essayist who wrote prose poetry throughout the 1980s. In the early 1980s, Liu Zaifu continued prose poetry's tradition of finding a place for the subjective and the aesthetic in the world of socialist prose. The first part of the chapter engages with his aesthetic and social philosophy, and uses that engagement to translate and read his best-known work, “Reading the Sea.” The second half of the chapter traces the impact of Liu's 1989 exile on his work. Liu’s post-exile works, published in Hong Kong, reveal the connection between prose poetry and the Chinese mainland context: once he leaves, Liu stops writing prose poetry in favor of literary essays. His work and his career therefore provide a crucial commentary on the line between orthodox and unorthodox prose poetry, and between prose poetry and other prose.

scholarly journals Impact of Western Pacific Subtropical High on Ozone Pollution over Eastern China

2020 ◽  
Author(s):  
Zhongjing Jiang ◽  
Jing Li ◽  
Xiao Lu ◽  
Cheng Gong ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Land Surface ◽  
Southern China ◽  
Surface Ozone ◽  
Eastern China ◽  
Decisive Role ◽  
Western Pacific Subtropical High ◽  
Northern China ◽  
Subtropical High ◽  
Ozone Pollution ◽  
Normal Surface

Abstract. Surface ozone is a major pollutant in Eastern China, especially during the summer season. The formation of surface ozone pollution highly depends on meteorological conditions as generally controlled regional circulation patterns. Here we show that summertime ozone pollution over Eastern China is distinctly modulated by the variability of West Pacific Subtropical High (WPSH), a major synoptic system that controls the summertime weather conditions of East Asia. Composite and regression analyses indicate that positive WPSH anomaly is associated with higher than normal surface ozone concentration over Northern China but lower ozone over Southern China. We show that this is mainly driven by changes in meteorological variables with stronger than normal WPSH leading to higher temperatures, stronger solar radiation at the land surface, lower relative humidity, and less precipitation in Northern China, favoring the production and accumulation of surface ozone. In contrast, all variables show reverse changes in Southern China under stronger WPSH. GEOS-Chem simulations reasonably reproduce the observed ozone changes associated with the WPSH and support the statistical analyses. Detailed contributions of different processes are quantified through budget diagnosis, which emphasizes the decisive role of chemistry. Natural emission of precursors from biogenic and soil sources accounts for ~30 % of the total surface ozone changes.

scholarly journals Drought Trend Analysis Based on the Standardized Precipitation–Evapotranspiration Index Using NASA’s Earth Exchange Global Daily Downscaled Projections, High Spatial Resolution Coupled Model Intercomparison Project Phase 5 Projections, and Assessment of Potential Impacts on China’s Crop Yield in the 21st Century

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2455
Author(s):  
Xiaolin Guo ◽  
Yuan Yang ◽  
Zhansheng Li ◽  
Liangzhi You ◽  
Chao Zeng ◽  
...  
Keyword(s):  
Crop Yield ◽  
Spatial Resolution ◽  
Crop Production ◽  
Southern China ◽  
Extreme Drought ◽  
Severe Drought ◽  
High Latitudes ◽  
Standardized Precipitation Evapotranspiration Index ◽  
Climate Data ◽  
The Impact

Drought is among the costliest natural disasters on both ecosystems and agroeconomics in China. However, most previous studies have used coarse resolution data or simply stopped short of investigating drought projection and its impact on crop yield. Motivated by the newly released higher-resolution climate projection dataset and the crucial need to assess the impact of climate change on agricultural production, the overarching goal of this study was to systematically and comprehensively predict future droughts at unprecedented resolutions over China as a whole. rather than region-specific projections, and then to further investigate its impact on crop yield by innovatively using a soil water deficit drought index. Methodologically, the drought projections were quantified from very high resolution climate data and further predicted impacts on crop yield over China using the standardized precipitation–evapotranspiration index (SPEI) at a relatively high (25 km) spatial resolution from NASA’s Earth Exchange Global Daily Downscaled Projections (NEX-GDDP). The results showed that (1) overall, China is projected to experience a significant decrease in SPEI (−0.15/decade under RCP (representative concentration pathway) 4.5; −0.14/decade under RCP8.5). Seasonally, the decreasing rate of SPEI is projected to be largest in winter (−0.2/decade and −0.31/decade) and the least in summer (−0.08/decade and −0.10/decade) under respective RCPs. (2) Regionally, winter/spring will get drier, especially at high latitudes/altitudes (North China and Tibetan plateau), and summer/autumn will get wetter in southern China. (3) Both the frequency and duration for medium and severe drought are projected to decrease, while extreme drought, particularly in high latitudes/altitudes, is projected to increase. (4) The percentage of the potential crop production affected by drought would increase to 36% (47%) by 2100 under RCP4.5 (RCP8.5). Especially, the ratio impacted by extreme drought is projected to increase over time and with much worse magnitude under RCP8.5; thus, adaptive crop policies are expected to address such a risk.

The Elusive Soul of Japanese Business

Worldview ◽  
1974 ◽  
Vol 17 (2) ◽  
pp. 31-36
Author(s):  
Donald Kirk
Keyword(s):  
Northern China ◽  
Chinese Mainland ◽  
Diplomatic Relations ◽  
The Chinese Mainland

Under autumn sky, all creaturesEmulate each other in freedomIn resentment at the vast skyI ask the spreading earthWho shall control over the fall and the rise?(Mao Tse-Tung)Mao Tse-tung composed the verse in 1925 before organizing the farmers of his native village into an “association to clean up the shame” of Japanese “invasion” of parts of northern China—the precursor to the spreading occupation of the Chinese mainland in the 1930's. A negotiator for China's Five-Metal Company presented a scroll, with the characters for the verse gracefully brushed in black ink, to Hosai Hyuga, president of Sumitomo Metal Industries, Ltd., in December, 1972, three months after Japan and the People's Republic opened diplomatic relations.

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.

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