Spatial and temporal variations of summer hot days and heat waves and their relationships with large-scale atmospheric circulations across Northeast China

2018 ◽  
Vol 38 (15) ◽  
pp. 5633-5645 ◽  
Author(s):  
Lei Wang ◽  
Wen J. Wang ◽  
Zhengfang Wu ◽  
Haibo Du ◽  
Xiangjin Shen ◽  
...  
Keyword(s):  
Northeast China ◽  
Large Scale ◽  
Heat Waves ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Atmospheric Circulations ◽  
Hot Days

scholarly journals Regional Climatic Features of the Arabian Peninsula

Atmosphere ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 220 ◽  
Author(s):  
Patlakas ◽  
Stathopoulos ◽  
Flocas ◽  
Kalogeri ◽  
Kallos
Keyword(s):  
Large Scale ◽  
Arabian Peninsula ◽  
Regional Climate ◽  
Atmospheric Model ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Spatial Distance ◽  
Temperature Extremes ◽  
Mean Temperature ◽  
Maximum Temperatures

The climate of the Arabian Peninsula is characterized by significant spatial and temporal variations, due to its complex topography and the large-scale atmospheric circulation. Furthermore, the role of dust in the formation of regional climate is considered to be crucial. In this work, the regional climatology for the Arabian Peninsula has been studied by employing a high resolution state of the art atmospheric model that included sophisticated physical parameterization schemes and online treatment of natural aerosol particles. The simulations covered a 30-year period (1986–2015) with a temporal resolution of 3 h and a spatial distance of 9 km. The main focus was given to the spatial and temporal variations of mean temperature and temperature extremes, wind speed and direction, and relative humidity. The results were evaluated using in situ measurements indicating a good agreement. An examination of possible climatic changes during the present climate was also performed through a comprehensive analysis of the trends of mean temperature and temperature extremes. The statistical significant trend values were overall positive and increased over the northwestern parts of the examined area. Similar spatial distributions were found for the daily minimum and maximum temperatures. Higher positive values emerged for the daily maxima.

Analysis of the extreme heat events in Iran

2017 ◽  
Vol 9 (4) ◽  
pp. 418-432 ◽  
Author(s):  
Hojjatollah Yazdanpanah ◽  
Josef Eitzinger ◽  
Marina Baldi
Keyword(s):  
Trend Analysis ◽  
Heat Wave ◽  
Heat Waves ◽  
Temporal Variations ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Positive Trend ◽  
Content Type ◽  
Hot Days

Purpose The purpose of this paper is to assess the spatial and temporal variations of extreme hot days (H*) and heat wave frequencies across Iran. Design/methodology/approach The authors used daily maximum temperature (Tmax) data of 27 synoptic stations in Iran. These data were standardized using the mean and the standard deviation of each day of the year. An extreme hot day was defined when the Z score of daily maximum temperature of that day was equal or more than a given threshold fixed at 1.7, while a heat wave event was considered to occur when the Z score exceeds the threshold for at least three continuous days. According to these criteria, the annual frequency of extreme hot days and the number of heat waves were determined for all stations. Findings The trend analysis of H* shows a positive trend during the past two decades in Iran, with the maximum number of H* (110 cases) observed in 2010. A significant trend of the number of heat waves per year was also detected during 1991-2013 in all the stations. Overall, results indicate that Iran has experienced heat waves in recent years more often than its long-term average. There will be more frequent and intense hot days and heat waves across Iran until 2050, due to estimated increase of mean air temperature between 0.5-1.1 and 0.8-1.6 degree centigrade for Rcp2.6 and Rcp8.8 scenarios, respectively. Originality/value The trend analysis of hot days and heat wave frequencies is a particularly original aspect of this paper. It is very important for policy- and decision-makers especially in agriculture and health sectors of Iran to make some adaptation strategies for future frequent and intense hot days over Iran.

Spatial and temporal variations of open straw burning based on fire spots in northeast China from 2013 to 2017

2021 ◽  
Vol 244 ◽  
pp. 117962
Author(s):  
Song Cui ◽  
Zihan Song ◽  
Leiming Zhang ◽  
Zhenxing Shen ◽  
Rupert Hough ◽  
...  
Keyword(s):  
Northeast China ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Straw Burning

scholarly journals Role of Convective Entrainment in Spatial Distributions of and Temporal Variations in Precipitation over Tropical Oceans

2014 ◽  
Vol 27 (23) ◽  
pp. 8707-8723 ◽  
Author(s):  
Nagio Hirota ◽  
Yukari N. Takayabu ◽  
Masahiro Watanabe ◽  
Masahide Kimoto ◽  
Minoru Chikira
Keyword(s):  
Large Scale ◽  
Lower Troposphere ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Spatial Distributions ◽  
Atmospheric Models ◽  
Tropical Oceans ◽  
Appropriate Treatment ◽  
Precipitation Events

Abstract The authors demonstrate that an appropriate treatment of convective entrainment is essential for determining spatial distributions of and temporal variations in precipitation. Four numerical experiments are performed using atmospheric models with different entrainment characteristics: a control experiment (Ctl), a no-entrainment experiment (NoEnt), an original Arakawa–Schubert experiment (AS), and an AS experiment with a simple empirical suppression of convection depending on cloud-layer humidity (ASRH). The fractional entrainment rates of AS and ASRH are constant for each cloud type and are very small in the lower troposphere compared with those in the Ctl, in which half of the buoyancy-generated energy is consumed by entrainment. Spatial and temporal variations in the observed precipitation are satisfactorily reproduced in the Ctl, but their amplitudes are underestimated with a so-called double intertropical convergence zone bias in the NoEnt and AS. The spatial variation is larger in the Ctl because convection is more active over humid ascending regions and more suppressed over dry subsidence regions. Feedback processes involving convection, the large-scale circulation, free tropospheric moistening by congestus, and radiation enhance the variations. The temporal evolution of precipitation events is also more realistic in the Ctl, because congestus moistens the midtroposphere, and large precipitation events occur once sufficient moisture is available. The large entrainment in the lower troposphere, increasing free tropospheric moistening by congestus and enhancing the coupling of convection to free tropospheric humidity, is suggested to be important for the realistic spatial and temporal variations.

scholarly journals Spatial and Temporal Variations of Heat Waves in China from 1961 to 2010

2014 ◽  
Vol 5 (2) ◽  
pp. 66-73 ◽  
Author(s):  
Ye Dian-Xiu ◽  
Yin Ji-Fu ◽  
Chen Zheng-Hong ◽  
Zheng You-Fei ◽  
Wu Rong-Jun
Keyword(s):  
Heat Waves ◽  
Temporal Variations ◽  
Spatial And Temporal Variations
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