Record-breaking high temperature in Southern China in 2017 and influence from the middle-latitude trough over the East of Japan

2021 ◽  
pp. 105615
Author(s):  
Zhang Jianming ◽  
Ding Ting ◽  
Gao Hui
Keyword(s):  
High Temperature ◽  
Southern China ◽  
Middle Latitude

scholarly journals Summer High Temperature Extremes over China Linked to the Pacific Meridional Mode

2020 ◽  
Vol 33 (14) ◽  
pp. 5905-5917
Author(s):  
Ming Luo ◽  
Ngar-Cheung Lau ◽  
Wei Zhang ◽  
Qiang Zhang ◽  
Zhen Liu
Keyword(s):  
High Temperature ◽  
Land Surface ◽  
Southern China ◽  
Eastern China ◽  
Northern China ◽  
Temperature Extremes ◽  
The Pacific ◽  
Meridional Mode ◽  
High Temperature Extremes ◽  
Pacific Meridional Mode

AbstractThis study investigates the association between summer high temperature extremes (HTEs) over China and the Pacific meridional mode (PMM) that is characterized by an anomalous north–south sea surface temperature gradient and an anomalous surface circulation over the northeastern subtropical Pacific. It is found that the HTE activities over most parts of southern China (particularly eastern China) are prominently intensified during the positive PMM phase and weakened during the negative phase. Further examinations suggest that the PMM is linked with HTEs in China through processes that entail both eastward and westward development of signals emanating from the PMM site. The westward development is associated with the formation of an anomalous low-level cyclone over the western North Pacific (WNP), which may be viewed as a Matsuno–Gill-type response to the off-equatorial heating in the eastern Pacific. This circulation change is accompanied by anomalous ascent over WNP and northern China, and subsidence over eastern China. On the other hand, the eastward development process is linked to the PMM-induced displacement of the East Asian jet stream and the generation of a midlatitude Rossby wave train. In the positive PMM phase, the above circulation changes are accompanied by anomalous air subsidence and enhanced adiabatic heating, reduced precipitation, anomalous lower-level anticyclone, and rising surface pressure over the eastern part of China. Moreover, the land surface of that region receives more solar radiation. Opposite changes are discernible over northern China. These changes are favorable for the occurrence and persistence of HTEs over eastern China and tend to suppress HTEs over northern China.

scholarly journals Evolution of the Circulation Anomalies and the Quasi-Biweekly Oscillations Associated with Extreme Heat Events in Southern China

2016 ◽  
Vol 29 (19) ◽  
pp. 6909-6921 ◽  
Author(s):  
Ruidan Chen ◽  
Zhiping Wen ◽  
Riyu Lu
Keyword(s):  
High Temperature ◽  
Southern China ◽  
Circulation Pattern ◽  
The Philippines ◽  
Extreme Heat ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
The North ◽  
Circulation Anomalies

Abstract Southern China, located in the tropical–subtropical East Asian monsoonal region, presents a unique anticyclonic–cyclonic circulation pattern during extreme heat (EH), obviously different from the typical anticyclone responsible for EH in many other regions. Associated with the evolution of EH in southern China, the anticyclonic–cyclonic anomalies propagate northwestward over the Philippines and southern China. Before the EH onsets, the anticyclonic anomaly dominates southern China, resulting in stronger subsidence over southern China and stronger southerly (southwesterly) flow over the western (northern) margins of southern China. The southerly (southwesterly) flow transports more water vapor to the north of southern China, thus, together with the local stronger subsidence, resulting in drier air condition and accordingly favoring the occurrence of EH. Conversely, after the EH onsets, the cyclonic component approaches southern China and offsets the high temperature. The oscillations of temperature and circulation anomalies over southern China exhibit a periodicity of about 10 days and indicate the influence of a quasi-biweekly oscillation, which originates from the tropical western Pacific and propagates northwestward. Therefore, the 5–25-day-filtered data are extracted to further analyze the quasi-biweekly oscillation. It turns out that the evolution of the filtered circulation remarkably resembles the original anomalies with comparable amplitudes, indicating that the quasi-biweekly oscillation is critical for the occurrence of EH in southern China. The quasi-biweekly oscillation could explain more than 50% of the intraseasonal variance of daily maximum temperature Tmax and vorticity over southern China and 80% of the warming amplitude of EH onsets. The close relationship between the circulation of the quasi-biweekly oscillation and the EH occurrence indicates the possibility of medium-range forecasting for high temperature in southern China.

scholarly journals Heat Waves in Southern China: Synoptic Behavior, Long-Term Change, and Urbanization Effects

2017 ◽  
Vol 30 (2) ◽  
pp. 703-720 ◽  
Author(s):  
Ming Luo ◽  
Ngar-Cheung Lau
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Large Scale ◽  
Heat Waves ◽  
Southern China ◽  
Positive Anomaly ◽  
Term Change ◽  
Pressure Anomaly ◽  
Westward Movement ◽  
The Pearl River

The characteristics of heat waves (HWs) in southern China in 1979–2010 are studied by using both reanalysis and station datasets. Guangdong Province of China (GDPC) is taken as an example. It is found that the westward movement of the western North Pacific subtropical high (WNPSH) is the primary factor for large-scale HWs occurring in GDPC. When an HW occurs, a hot and dry atmospheric column prevails over southern China. The region is overlaid by anomalous subsidence, which leads to warming, and clear sky, which causes greater solar heating. HWs are accompanied by an anomalous high pressure center and anticyclone near the surface, with anomalous land–sea northwesterly flow, thus reducing sea–land moisture transport and drying the atmosphere over land. The evolution of the high pressure anomaly and high temperature is associated with the westward displacement of WNPSH, with a prominent positive anomaly in 500-hPa height migrating westward. All these features associated with HWs in GDPC coincide with high-temperature extremes in the whole region of southern China and parts of Indochina. Significant increases in HW frequency (+0.19 events decade−1), HW days (+2.86 days decade−1), the duration of the longest event (+0.38 days decade−1), and the hottest temperature of the hottest event (+0.23°C decade−1) are also observed. These upward trends are more prominent in the Pearl River delta (PRD) region, and urbanization contributes to nearly 50% of the increase in HW frequency in PRD. It is also noticed that HWs are commencing earlier and ending later, and urbanization may advance the timing of the onset of HW events.

scholarly journals Colored Shade Nets can Relieve Abnormal Fruit Softening and Premature Leaf Senescence of “Jumeigui” Grapes during Ripening Under Greenhouse Conditions

2021 ◽  
Author(s):  
Qian Zha ◽  
Xiaojun Xi ◽  
Xiangjing Yin ◽  
Yani He ◽  
Aili Jiang
Keyword(s):  
High Temperature ◽  
Leaf Senescence ◽  
Production Efficiency ◽  
Light Transmission ◽  
Southern China ◽  
Aluminum Foil ◽  
Soluble Solids ◽  
Fruit Softening ◽  
Blue Shade ◽  
Premature Leaf Senescence

Abstract When grapes reach maturity, they usually experience extremely high-temperature periods in southern China, causing premature leaf senescence, abnormal fruit softening, and fruiting period shortening. Their quality and production efficiency are also severely affected. ‘Jumeigui’ grapes were examined in terms of fruit quality and leaf senescence under shading treatments; green, blue, black, and gray aluminum foil nets were used for shading, and their spectra were measured. At the same density, shade net color significantly affected cooling and shading efficiencies, and gray net had the best light transmission and cooling effect. Shading treatment significantly alleviated abnormal grape softness during hot periods. Total soluble solids (TSS) content and grape coloration were affected under gray, blue, and green shade nets. TSS exceeded 18% under gray, blue, and green nets, meeting the requirements of first-class high-quality fruit. However, peel coloration was not notably affected under gray and blue shade nets, while the non-shading treatment produced clear heat-stress damage, especially on the edges of old leaves. The net photosynthetic rate of the bottom five old leaves under the non-shading treatment was significantly lower than that under the shading treatment, indicating that high light and heat caused premature leaf senescence. In summary, colored shade nets can reduce the temperature and light in the greenhouse, while alleviating premature senescence of perennial grape plants. However, the quality of the grapes treated using black shade nets was poor; superior quality was achieved using gray and blue shade nets. These results can be applied in future cultivation facilities during high-temperature periods.

scholarly journals A plant reovirus hijacks endoplasmic reticulum-associated degradation machinery to promote efficient viral transmission by its planthopper vector under high temperature conditions

2021 ◽  
Vol 17 (3) ◽  
pp. e1009347
Author(s):  
Xiangzhen Yu ◽  
Dongsheng Jia ◽  
Zhen Wang ◽  
Guangjun Li ◽  
Manni Chen ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
High Temperature ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Protein Quality ◽  
Southern China ◽  
Nonstructural Protein ◽  
Viral Transmission ◽  
Endoplasmic Reticulum Associated Degradation ◽  
Er Membrane

In the field, many insect-borne crop viral diseases are more suitable for maintenance and spread in hot-temperature areas, but the mechanism remains poorly understood. The epidemic of a planthopper (Sogatella furcifera)-transmitted rice reovirus (southern rice black-streaked dwarf virus, SRBSDV) is geographically restricted to southern China and northern Vietnam with year-round hot temperatures. Here, we reported that two factors of endoplasmic reticulum-associated degradation (ERAD) machinery, the heat shock protein DnaJB11 and ER membrane protein BAP31, were activated by viral infection to mediate the adaptation of S. furcifera to high temperatures. Infection and transmission efficiencies of SRBSDV by S. furcifera increased with the elevated temperatures. We observed that high temperature (35°C) was beneficial for the assembly of virus-containing tubular structures formed by nonstructural protein P7-1 of SRBSDV, which facilitates efficient viral transmission by S. furcifera. Both DnaJB11 and BAP31 competed to directly bind to the tubule protein P7-1 of SRBSDV; however, DnaJB11 promoted whereas BAP31 inhibited P7-1 tubule assembly at the ER membrane. Furthermore, the binding affinity of DnaJB11 with P7-1 was stronger than that of BAP31 with P7-1. We also revealed that BAP31 negatively regulated DnaJB11 expression through their direct interaction. High temperatures could significantly upregulate DnaJB11 expression but inhibit BAP31 expression, thereby strongly facilitating the assembly of abundant P7-1 tubules. Taken together, we showed that a new temperature-dependent protein quality control pathway in the ERAD machinery has evolved for strong activation of DnaJB11 for benefiting P7-1 tubules assembly to support efficient transmission of SRBSDV in high temperatures. We thus deduced that ERAD machinery has been hitchhiked by insect-borne crop viruses to enhance their transmission in tropical climates.

scholarly journals Variability and Trends of High Temperature, High Humidity, and Sultry Weather in the Warm Season in China during the Period 1961–2004

2011 ◽  
Vol 50 (1) ◽  
pp. 127-143 ◽  
Author(s):  
Xiaohui Shi ◽  
Chungu Lu ◽  
Xiangde Xu
Keyword(s):  
High Temperature ◽  
East Asian Monsoon ◽  
Southern China ◽  
Warm Season ◽  
Northern China ◽  
Annual Number ◽  
Daily Maximum ◽  
High Humidity ◽  
Spatial Differences ◽  
Increasing Trends

Abstract Using the daily maximum air temperature and mean humidity observations at 394 surface weather stations across China, the changes in the annual number of days of high temperature weather (HTW), high humidity weather (HHW), and sultry weather (STW) in China over the period 1961–2004 are studied. The results indicate that there were considerable spatial differences and temporal variability of HTW, HHW, and STW across China. Under a climatic mean condition, a notable feature is that southeastern China is the region of collocation of high values of the annual number of days of HTW, HHW, and STW, as well as the region of the most significant variabilities of these parameters. About 55% of the stations in China have increasing trends of the annual number of days of HTW. Most stations in China show decreasing trends of the annual number of days of HHW and are mainly located either in the area south of 30°N or in northern and northeastern China. The stations with increasing trends of the annual number of days of STW are mainly located in northern China, while the stations that have decreasing trends are primarily located in southern China. The analysis results suggest that the variability of the annual number of days of STW corresponds mainly to HTW, and less to HHW. The change in the East Asian monsoon may be responsible for the changes of these statistics in extreme weather in China.

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