scholarly journals Fluid Dynamics Simulation and Temperature Gradient Validation along a Greenhouse Temperature Gradient

2020 ◽  
Author(s):  
Sung Kyeom Kim ◽  
Hee Ju Lee ◽  
Seung Hwan Wi ◽  
Seong-Won Lee ◽  
ILHWAN Seo
Keyword(s):  
Climate Change ◽  
Fluid Dynamics ◽  
Temperature Gradient ◽  
Temperature Change ◽  
Temperature Difference ◽  
Physiological Response ◽  
Crop Production ◽  
Extreme Weather ◽  
Temperature Gradients ◽  
Response To Temperature

Abstract Background: Climate change is increasing the vulnerability of horticultural crop cultivation and production. It is urgent to study such extreme weather phenomena (heatwave, drought, etc.), and in particular, to evaluate crop productivity according to temperature change. For this purpose, the crop physiological response to temperature change in simulated weather conditions was studied. However, there is a limitation in artificial light wavelength, which requires experiments to be carried out in protected facilities or open fields. In this study, we simulated temperature differences with computational fluid dynamics (CFD) in tunnel-type greenhouses. They can create temperature gradients and improve the accuracy of CFD with vertically and horizontally measured temperature profiles. The growth and physiological response of Kimchi cabbage were examined and validated using a temperature gradient within a semi-closed plastic tunnel.Results: Correlation coefficients of measured heights were: 1.120, 0.597, and 0.459. Root mean square error was below 0.1025, which means the CFD simulation values were highly accurate. The error analysis showed that it was possible to accurately predict temperature gradients change within a semi-closed tunnel-type greenhouse using CFD techniques. CFD results showed an average error of 0.597°C compared to field monitoring results. The maximum temperature difference of GTG was 5.7°C, suggesting a well-controlled set point (6°C difference between outside conditions and inside conditions of GTG). In a cloudy day, the gradient temperature of GTG was well maintained by the set differential temperature (dT), which suggests that the set dT was not precisely and accurately performed in GTG of a sunny day. There was a significant difference in the growth, net photosynthetic rate, transpiration rate, and Ci concentration along with temperature differences in GTG. Conclusions: CFD can simulate temperature gradient distribution in a tunnel-type greenhouse and predict the temperature difference for equipment with different specifications. These facilities can be used in climate change-related studies, such as assessment of crop production area optimization, crop physiological response to temperature, vulnerability assessment of crop production under increasing temperatures, or extreme weather.

scholarly journals Fluid Dynamics Simulation and Temperature Gradient Validation along a Greenhouse Temperature Gradient

2020 ◽  
Author(s):  
Sung Kyeom Kim ◽  
Hee Ju Lee ◽  
Seung Hwan Wi ◽  
Seong-Won Lee ◽  
ILHWAN Seo
Keyword(s):  
Climate Change ◽  
Fluid Dynamics ◽  
Temperature Gradient ◽  
Temperature Change ◽  
Temperature Difference ◽  
Physiological Response ◽  
Crop Production ◽  
Extreme Weather ◽  
Temperature Gradients ◽  
Response To Temperature

Abstract Background: Climate change is increasing the vulnerability of horticultural crop cultivation and production. It is urgent to study such extreme weather phenomena (heatwave, drought, etc.), and in particular, to evaluate crop productivity according to temperature change. For this purpose, the crop physiological response to temperature change in simulated weather conditions was studied. However, there is a limitation in artificial light wavelength, which requires experiments to be carried out in protected facilities or open fields. In this study, we simulated temperature differences with computational fluid dynamics (CFD) in tunnel-type greenhouses. They can create temperature gradients and improve the accuracy of CFD with vertically and horizontally measured temperature profiles. The growth and physiological response of Kimchi cabbage were examined and validated using a temperature gradient within a semi-closed plastic tunnel.Results: Correlation coefficients of measured heights were: 1.120, 0.597, and 0.459. Root mean square error was below 0.1025, which means the CFD simulation values were highly accurate. The error analysis showed that it was possible to accurately predict temperature gradients change within a semi-closed tunnel-type greenhouse using CFD techniques. CFD results showed an average error of 0.597°C compared to field monitoring results. The maximum temperature difference of GTG was 5.7°C, suggesting a well-controlled set point (6°C difference between outside conditions and inside conditions of GTG). In a cloudy day, the gradient temperature of GTG was well maintained by the set differential temperature (dT), which suggests that the set dT was not precisely and accurately performed in GTG of a sunny day. There was a significant difference in the growth, net photosynthetic rate, transpiration rate, and Ci concentration along with temperature differences in GTG.Conclusions: CFD can simulate temperature gradient distribution in a tunnel-type greenhouse and predict the temperature difference for equipment with different specifications. These facilities can be used in climate change-related studies, such as assessment of crop production area optimization, crop physiological response to temperature, vulnerability assessment of crop production under increasing temperatures, or extreme weather.

scholarly journals Consequences of Climate Change Impacts and Incidences of Extreme Weather Events in Relation to Crop Production in Bhutan

2020 ◽  
Vol 12 (10) ◽  
pp. 4319 ◽  
Author(s):  
Ngawang Chhogyel ◽  
Lalit Kumar ◽  
Yadunath Bajgai
Keyword(s):  
Climate Change ◽  
Crop Production ◽  
Climatic Factors ◽  
Climate Change Impacts ◽  
Extreme Weather ◽  
Crop Damage ◽  
Extreme Weather Events ◽  
Cropping Pattern ◽  
The People ◽  
Weather Events

Being a country in the Himalayas, Bhutan is highly prone to the vagaries of weather events that affect agricultural production and the subsequent livelihood of the people. To identify the main issues that affect crop production and the decisions of farmers, a survey was conducted in three different agro-ecosystems in Bhutan. Our key findings indicate that farming and the decisions of farmers were largely affected by different climatic and non-climatic factors. These were in descending order of importance: irrigation availability > farm labour > crop seasonality > crop damage (climatic) > land holding > crop damage (wildlife) > crop damage (diseases and pests). The most important consequences of climate change impacts were the drying of irrigation sources (4.35) and crop losses due to weather events (4.10), whereas land fallowing, the occurrence of flood and soil erosion, weed pressure and changes in cropping pattern (with mean ratings of 2.53–3.03) experienced lesser consequences. The extreme weather events, such as untimely rains, drought and windstorms, were rated as the ‘most common’ to ‘common’ occurrences, thus inflicting a crop loss of 1–19%. These confirm our hearsay knowledge that extreme weather events have major consequences on irrigation water, which is said to be either drying or getting smaller in comparison to the past. Therefore, Bhutan must step up its on-ground farmer-support system towards improving the country’s food production, whilst embracing climate smart farm technologies for adapting to the impacts of change.

FACTORS INFLUENCING RICE FARMERS’ ADAPTATION STRATEGIES TO CLIMATE CHANGE AND EXTREME WEATHER EVENT IMPACTS IN BANGLADESH

2019 ◽  
Vol 10 (03) ◽  
pp. 1950012 ◽  
Author(s):  
KHADIYA AKTAR MAYA ◽  
MD. ABDUR RASHID SARKER ◽  
JEFF GOW
Keyword(s):  
Climate Change ◽  
Crop Production ◽  
Rice Variety ◽  
Extreme Weather ◽  
Adaptation Strategies ◽  
Farm Size ◽  
Extreme Weather Events ◽  
Climate Data ◽  
Adaptation Measures ◽  
Rice Farmers

Introduction: Climate change has emerged as a major threat to Bangladesh. Higher and fluctuating temperatures and changes in rainfall caused by climate change and extreme weather events have reduced crop production. A better understanding of the local dimensions of vulnerability is therefore essential to develop appropriate adaptation measures that can alleviate these adverse impacts. Purpose and methods: The main purpose of this study was to identify the determinants of Aman rice farmers’ choice of adaptation strategies to climate change and weather in Khulna district, Bangladesh. About 100 farm households susceptible to salinity intrusion, extreme temperatures and drought were surveyed, and these data were supplemented by major climate data of the district for 65 years (1948–2013). A binary logistic regression was then utilized to estimate the factors that influence households’ choice of adaptation strategies. Results and Conclusions: About 97% of farmers perceived that the climate had changed over the past 30 years while only 3% did not. Further, 97% believed that rainfall had decreased and reduced rice production, yet the data show this not to be the case with a significant increase in rainfall observed in the area in the study period. About 89% of farmers have undertaken some form(s) of adaptation and they were further asked about their main adaptation type. Family size, annual income, farmer-to-farmer extension and access to subsidies have a positive and significant impact on rice farmers’ adaptation strategies to climate and weather change effects. Farm size and credit access had a negative and significant impact on adaptation. Four variables: age, education, household assets and occupation were not statistically significant in explaining adaption strategies. The chief adaptation strategies of farmers are cultivation of salinity-tolerant rice, rice variety switching, replanting of rice, changing planting dates, conversion of rice paddy to fish production and use of different crop varieties in alternate years.

Horizontal Temperature Gradient at 200 MB and Adjacent Levels

1956 ◽  
Vol 37 (2) ◽  
pp. 47-54
Author(s):  
Adam Kochanski
Keyword(s):  
Temperature Gradient ◽  
Temperature Difference ◽  
Wind Shear ◽  
Extreme Temperature ◽  
Vertical Wind Shear ◽  
Temperature Gradients ◽  
Horizontal Temperature Gradient ◽  
Horizontal Gradients ◽  
Gradient Measurements ◽  
Horizontal Temperature Gradients

Horizontal temperature gradients as large as 7C° per distance of one degree latitude are observed occasionally on 200-mb maps and (with a generally opposite direction) on 500-mb maps. These values are derived from gradient measurements in the vicinity of stations with temperature observations. Aircraft reports yield still higher horizontal gradients: 9C° to 11C° per 1 deg lat. An extreme temperature difference of 13C° over a distance of % deg lat appears feasible, based on extrapolation of differences found over greater distances. The last value is equivalent geostrophically to a vertical wind shear (allegedly observed by aircraft) of 60 kts/1000 ft.

scholarly journals Crop Microclimate Modification to Address Climate Change

2021 ◽  
Vol 8 (9) ◽  
pp. 384-395
Author(s):  
Udit Debangshi
Keyword(s):  
Climate Change ◽  
Food Security ◽  
Crop Production ◽  
Crop Productivity ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Weather Events ◽  
Efficiency And Effectiveness ◽  
Strong Winds ◽  
Climatic Elements

Climate-related agricultural vulnerabilities, as well as their implications for food security and farm livelihoods, have been extensively documented. Extreme weather events such as floods, droughts, heat and cold waves, hailstorms, strong winds, cyclones, and other weather events have increased the exposures of agriculture to climate risk. These processes are hampered by a lack of appropriate climatic elements, resulting in an unfavourable drop in crop productivity. Increased frequency and intensity of droughts and floods, as well as erratic precipitation patterns are predicted to increase year-to-year yield variability in crop production. Microclimate, which refers to the climatic elements in the immediate vicinity of the plants, is critical because it regulates and affects the physiological reactions of the plants as well as the energy exchange activities between the plant and its surroundings. Implementation of such microclimatic modifications in crop production are required to manage extreme weather risks and boost crop output in order to increase food security and agricultural sustainability in this changing climate. The goal of this paper is to improve crop production and land productivity by modifying microclimate as a manifestation of the efficiency and effectiveness of growth factor utilisation. Keywords: Agriculture's vulnerability, Crop productivity, Climate change, Microclimatic modifications.

Teresa Mannion and the Emergence of Extreme Weather Culture in Ireland

2019 ◽  
Vol 49 (1) ◽  
pp. 135-150
Author(s):  
Diane Negra
Keyword(s):  
Climate Change ◽  
At Risk ◽  
Popular Culture ◽  
Extreme Weather ◽  
Cross Cultural ◽  
Viral Video ◽  
Cultural Information ◽  
Strong Winds ◽  
Risk Coverage

In this article I consider how registers of weather media carry/convey cultural information, specifically how texts about extreme weather articulate with investment in a supposed post-recession restored normality marked by the Irish government's commitment to deregulated transnational capitalism. I maintain that, in a process of cross-cultural remediation, sensationalist codes of US weather media that discursively manage awareness of systemic climate problems are just starting to infiltrate the Irish broadcasting environment. In early December 2015 RTÉ’s Teresa Mannion covered a strong gale, Storm Desmond, amidst inclement conditions in Salthill, Co Galway. Modelling the kind of ‘body at risk’ coverage consummately performed by US Weather Channel personnel, Mannion could barely speak over the lashing rain and strong winds in a dramatic broadcast that quickly became a viral video. This article analyses the fascination with Mannion's piece and its memetic, and attends to the nature of the pleasure taken in her on-camera discomfiture and the breach of gendered territory committed by Mannion at a time when national popular culture in Ireland is under increased obligation to identify and explain climate change-related extreme weather.

Sign in / Sign up

Export Citation Format

Share Document