scholarly journals Comparative analysis of frequency of dry winds occurrence in Ukraine in the mid-20th century and at the beginning of the 21st century

2018 ◽  
pp. 57-63
Author(s):  
M. O. Slizhe
Keyword(s):  
Comparative Analysis ◽  
Large Scale ◽  
Crop Yields ◽  
Regional Climate ◽  
Temporal Distribution ◽  
Vegetation Period ◽  
Spatial And Temporal Distribution ◽  
Urgent Problem ◽  
The South ◽  
Summer Time

Dry winds in Ukraine present a dangerous phenomenon which can significantly impact on crop yields. The winds damage agricultural crops active development of which occurs in spring and summer time. Their impact can in a short time reduce or destroy further yield. Study of spatial and temporal distribution of the dry winds, their meteorological characteristics, dynamics of their development and circulation processes resulting in their formation in Ukraine is a very urgent problem because almost every year the dry winds and droughts occur at the time of vegetation period. The current research of spatial and temporal distribution of the dry winds and its meteorological characteristics on the territory of Ukraine under the conditions of changed climate is an urgent problem because this phenomenon occurs over almost every vegetation period. The paper describes the results of comparative analysis of average number of days witnessing the dry winds at 14 meteorological stations in Ukraine located in different agro-climatic zones for the periods of 1936-1964 and 1995-2015. The number of dry winds significantly increased at most of such stations located in different parts of Ukraine. Same as over previous periods, the greatest repetition of days with the dry winds occurred in the south and the south-east of the country where, according to the data from some meteostations, vegetation period may, on average, consist of up to 27 days when dry winds blow. The reason for such increase is explained, firstly, by change of the large-scale atmospheric circulation resulting in weakening of the heat and moisture inter-latitude exchange which in its turn causes change of the temperature and humidity regime in Ukraine and, secondly, by increase of frequency of synoptic processes accompanied by formation of arid phenomena on the territory of the country. These changes could be traced when observing the positive anomalies of average air temperature during recent decades. The negative anomalies of precipitation and change in their distribution contribute to the formation of conditions that increase frequency and intensity of droughts. The obtained results indicate that changes of the regional climate contributed to the increase of frequency and prevalence of the dry winds in Ukraine.

scholarly journals Analysis of the Spatial and Temporal Distribution of Process Gases within Municipal Biowaste Compost

2019 ◽  
Vol 11 (8) ◽  
pp. 2340 ◽  
Author(s):  
Stegenta ◽  
Sobieraj ◽  
Pilarski ◽  
Koziel ◽  
Białowiec
Keyword(s):  
Cross Sections ◽  
Large Scale ◽  
Temporal Distribution ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
O2 Evolution ◽  
Spatial And Temporal Distribution ◽  
Ambient Conditions ◽  
Process Gas ◽  
Process Gases

Composting processes reduce the weight and volume of biowaste and produce products that can be used in agriculture (e.g., as fertilizer). Despite the benefits of composting, there are also problems such as odors and the emission of pollutants into the atmosphere. This research aimed to investigate the phenomenon of process gas (CO, CO2, NO, O2) evolution within a large-scale municipal composter. The effects of turning frequency and pile location (outdoor vs. indoors) on process gas and temperature spatial and temporal evolution were studied in six piles (37‒81 tons of initial weight) over a six-month period. The biowaste consisted of green waste and municipal sewage sludge. The chemical composition and temperature of process gases within four cross sections with seven sampling locations were analyzed weekly for ~7–8 weeks (a total of 1375 cross sections). The aeration degree, temperature, CO, CO2, and NO concentration and their spatial and temporal distribution were analyzed. Final weight varied from 66% reduction to 7% weight gain. Only 8.2% of locations developed the desired chimney effect (utilizing natural buoyancy to facilitate passive aeration). Only 31.1% of locations reached thermophilic conditions (necessary to inactivate pathogens). Lower O2 levels corresponded with elevated CO2 concentrations. CO production increased in the initial composting phase. Winter piles were characterized by the lowest CO content. The most varied was the NO distribution in all conditions. The O2 concentration was lowest in the central part of the pile, and aeration conditions were good regardless of the technological regime used. Turning once a week was sufficient overall. Based on the results, the most favorable recommended procedure is turning twice a week for the first two weeks, followed by weekly turning for the next two weeks. After that, turning can be stopped unless additional removal of moisture is needed. In this case, weekly turning should continue until the process is completed. The size of the pile should follow the surface-to-volume ratio: <2.5 and <2 for cooler ambient conditions.

scholarly journals The sensitivity of the Seychelles–Chagos thermocline ridge to large-scale wind anomalies

2009 ◽  
Vol 66 (7) ◽  
pp. 1455-1466 ◽  
Author(s):  
Juliet C. Hermes ◽  
Chris J. C. Reason
Keyword(s):  
Indian Ocean ◽  
Large Scale ◽  
Regional Climate ◽  
Austral Summer ◽  
Tropical Indian Ocean ◽  
Ocean Model ◽  
The South ◽  
South Indian Ocean ◽  
Southwest Indian Ocean ◽  
South Indian

Abstract Hermes, J. C., and Reason, C. J. C. 2009. The sensitivity of the Seychelles–Chagos thermocline ridge to large-scale wind anomalies. – ICES Journal of Marine Science, 66: 1455–1466. The Seychelles–Chagos thermocline ridge (SCTR) in the southwest tropical Indian Ocean is important for regional climate, the Madden–Julian Oscillation, as well as upper-ocean nutrients and related phytoplankton and zooplankton densities. Subsurface variability in this region has been proved to influence the overlying sea surface temperatures, which in turn can influence eastern African rainfall. There is evidence that austral summers with a deeper (shallower) SCTR tend to have more (less) tropical cyclone (TC) days in the Southwest Indian Ocean. The importance of this relationship was underlined during the 2006/2007 austral summer, when areas of Madagascar and central Mozambique experienced devastating floods, because of ten named tropical storms, including several intense TCs, effecting on these areas. At the same time, the SCTR during this season was anomalously deep, partly because of a downwelling Rossby wave that propagated across the South Indian Ocean during the previous austral winter/spring. In this paper, a regional ocean model is used to investigate the effect of remote forcing on this region and to study the sensitivity of the SCTR to changes in the large-scale winds over the South Indian Ocean, with a particular focus on the events of the 2006/2007 austral summer.

scholarly journals SPATIAL AND TEMPORAL DISTRIBUTION OF THE CLOUD HEIGHT AND CLOUD THICKNESS OVER CHINA AND THE ADJACENT AREAS BASED ON CALIOP

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 15-22
Author(s):  
X. Feng ◽  
H. K. Cai ◽  
B. W. Wang ◽  
X. M. Li ◽  
L. Zhang
Keyword(s):  
Regional Differences ◽  
Temporal Distribution ◽  
The Tibetan Plateau ◽  
Spatial And Temporal Distribution ◽  
The South ◽  
The North ◽  
Cloud Height ◽  
The Mean ◽  
Cloud Thickness ◽  
The Western Pacific

Abstract. Based on CALIOP data, spatial and temporal distribution of cloud height and thickness over China as well as the adjacent areas have been analysed in this paper. The results show significant regional differences. The heights of clouds that lie to the south of 27.6°N are greater than those to the north of 27.6°N. The highest and thickest clouds are located above the Bay of Bengal and the Western Pacific, while the lowest values distribute in the northwest of the Tibetan Plateau and Sichuan Basin. The clouds ranging from 0.3 km to 0.6 km thickness account for a large proportion of total clouds. And the probability of occurrence of clouds decreases as cloud thickness increases. Overall, within the area under study, the thick clouds are higher than the thin clouds. Besides, low and thin clouds occur more frequently than high and thick clouds. As for their seasonal variation, the height of clouds peaks in summer. In addition, the mean of cloud thickness to the south of 27.6°N is 2.4 km thicker in summer than in any other season.

Spatial and temporal incidence of insect pests in farmers’ cabbage fields in Senegal

2017 ◽  
Vol 37 (04) ◽  
pp. 225-233 ◽  
Author(s):  
Babacar Labou ◽  
Thierry Brévault ◽  
Serigne Sylla ◽  
Mamadou Diatte ◽  
Dominique Bordat ◽  
...  
Keyword(s):  
Insect Pests ◽  
Tomato Fruit ◽  
Diamondback Moth ◽  
Temporal Distribution ◽  
Dry Season ◽  
Effect Of Temperature ◽  
Small Scale ◽  
Vegetable Production ◽  
Spatial And Temporal Distribution ◽  
The South

Abstract In Senegal, damage caused by insect pests is a major obstacle to seasonal stability and an increase in cabbage production. Little is known about the spatial and temporal distribution of cabbage pests, which makes the design of management recommendations to small-scale farmers challenging. The objectives of this study were to: (i) evaluate the status of insect pests observed in cabbage farmers’ fields; (ii) give information on the spatial and temporal distribution of key pests and (iii) assess the effect of temperature, insecticide applications, and host crop abundance on their incidence. A total of 116 cabbage fields were monitored for insect pests and related damage over four crop cycles, from October 2012 to May 2014, in the main vegetable producing area of Senegal (Niayes). The diamondback moth Plutella xylostella (L.) was by far the most important pest present in all the fields and with high levels of incidence (37.1% infested plants), particularly in the latter part of the dry season in the South of Niayes (50% infested plants). The cabbage webworm Hellula undalis (F.) was mainly observed in the early dry season in the south of Niayes, with an incidence of up to 12.5% infested plants. More surprising was the detection of the tomato fruit worm Helicoverpa armigera (Hübner), with damage of up to 9.4% of cabbage heads. The incidence of sucking pests such as whiteflies Bemisia tabaci (Gennadius), or aphids (including Lipaphis pseudobrassicae (Davis, 1914), Myzus persicae (Sulzer) or Brevicoryne brassicae (L.)) was generally low. The incidence of P. xylostella increased significantly with the number of insecticide applications, indicating that control deployed by growers was ineffective. The incidence of H. undalis did not depend on the number of insecticide applications, but significantly increased with host crop abundance and decreased with temperature. This study is a first step towards developing alternative pest management strategies in the framework of sustainable vegetable production systems.

Spatial and temporal distribution of pore gas concentrations during mainstream large-scale trough composting in China

2018 ◽  
Vol 75 ◽  
pp. 297-304 ◽  
Author(s):  
Jianfei Zeng ◽  
Xiuli Shen ◽  
Xiaoxi Sun ◽  
Ning Liu ◽  
Lujia Han ◽  
...  
Keyword(s):  
Large Scale ◽  
Temporal Distribution ◽  
Spatial And Temporal Distribution
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