WorldWideScience

Sample records for modelling greenhouse temperature

  1. Control and modelling of vertical temperature distribution in greenhouse crops

    NARCIS (Netherlands)

    Kempkes, F.L.K.; Bakker, J.C.; Braak, van de N.J.

    1998-01-01

    Based on physical transport processes (radiation, convection and latent heat transfer) a model has been developed to describe the vertical temperature distribution of a greenhouse crop. The radiation exchange factors between heating pipes, crop layers, soil and roof were determined as a function of

  2. Analysis of Variation Characters and Prediction Model of Soil Temperature in Solar Greenhouse

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the soil temperature changes and its forecast model in greenhouse by solar heat. [Method] Annual and daily variation characters of soil temperature were analyzed in this paper by using the observation data of air temperature out of solar greenhouse and different layers soil temperature in it. The soil temperature (daily maximum, daily minimum and daily mean) forecasting models were also studied. Simulation and test were conducted to the forecast model of soil temperature in ...

  3. Temperature Field-Wind Velocity Field Optimum Control of Greenhouse Environment Based on CFD Model

    Directory of Open Access Journals (Sweden)

    Yongbo Li

    2014-01-01

    Full Text Available The computational fluid dynamics technology is applied as the environmental control model, which can include the greenhouse space. Basic environmental factors are set to be the control objects, the field information is achieved via the division of layers by height, and numerical characteristics of each layer are used to describe the field information. Under the natural ventilation condition, real-time requirements, energy consumption, and distribution difference are selected as index functions. The optimization algorithm of adaptive simulated annealing is used to obtain optimal control outputs. A comparison with full-open ventilation shows that the whole index can be reduced at 44.21% and found that a certain mutual exclusiveness exists between the temperature and velocity field in the optimal course. All the results indicate that the application of CFD model has great advantages to improve the control accuracy of greenhouse.

  4. [An early warning method of cucumber downy mildew in solar greenhouse based on canopy temperature and humidity modeling].

    Science.gov (United States)

    Wang, Hui; Li, Mei-lan; Xu, Jian-ping; Chen, Mei-xiang; Li, Wen-yong; Li, Ming

    2015-10-01

    The greenhouse environmental parameters can be used to establish greenhouse nirco-climate model, which can combine with disease model for early warning, with aim of ecological controlling diseases to reduce pesticide usage, and protecting greenhouse ecological environment to ensure the agricultural product quality safety. Greenhouse canopy leaf temperature and air relative humidity, models were established using energy balance and moisture balance principle inside the greenhouse. The leaf temperature model considered radiation heat transfer between the greenhouse crops, wall, soil and cover, plus the heat exchange caused by indoor net radiation and crop transpiration. Furthermore, the water dynamic balance in the greenhouse including leaf transpiration, soil evaporation, cover and leaf water vapor condensation, was considered to develop a relative humidity model. The primary infection and latent period warning models for cucumber downy mildew (Pseudoperonospora cubensis) were validated using the results of the leaf temperature and relative humidity model, and then the estimated disease occurrence date of cucumber downy mildew was compared with actual disease occurrence date of field observation. Finally, the results were verified by the measured temperature and humidity data of September and October, 2014. The results showed that the root mean square deviations (RMSDs) of the measured and estimated leaf temperature were 0.016 and 0.024 °C, and the RMSDs of the measured and estimated air relative humidity were 0.15% and 0.13%, respectively. Combining the result of estimated temperature and humidity models, a cucumber disease early warning system was established to forecast the date of disease occurrence, which met with the real date. Thus, this work could provide the micro-environment data for the early warning system of cucumber diseases in solar greenhouses.

  5. Relative Contribution of Greenhouse Gases and Ozone Change to Temperature Trends in the Stratosphere: A Chemistry/Climate Model Study

    Science.gov (United States)

    Stolarski, Richard S.; Douglass, A. R.; Newman, P. A.; Pawson, S.; Schoeberl, M. R.

    2006-01-01

    Long-term changes in greenhouse gases, primarily carbon dioxide, are expected to lead to a warming of the troposphere and a cooling of the stratosphere. We examine the cooling of the stratosphere and compare the contributions greenhouse gases and ozone change for the decades between 1980 and 2000. We use 150 years of simulation done with our coupled chemistry/climate model (GEOS 4 GCM with GSFC CTM chemistry) to calculate temperatures and constituents fiom,1950 through 2100. The contributions of greenhouse gases and ozone to temperature change are separated by a time-series analysis using a linear trend term throughout the period to represent the effects of greenhouse gases and an equivalent effective stratospheric chlorine (EESC) term to represent the effects of ozone change. The temperature changes over the 150 years of the simulation are dominated by the changes in greenhouse gases. Over the relatively short period (approx. 20 years) of ozone decline between 1980 and 2000 changes in ozone are competitive with changes in greenhouse gases. The changes in temperature induced by the ozone change are comparable to, but smaller than, those of greenhouse gases in the upper stratosphere (1-3 hPa) at mid latitudes. The ozone term dominates the temperature change near both poles with a negative temperature change below about 3-5 hPa and a positive change above. At mid latitudes in the upper stratosphere and mesosphere (above about 1 hPa) and in the middle stratosphere (3 to 70 ma), the greenhouse has term dominates. From about 70 hPa down to the tropopause at mid latitudes, cooling due to ozone changes is the largest influence on temperature. Over the 150 years of the simulation, the change in greenhouse gases is the most important contributor to temperature change. Ozone caused a perturbation that is expected to reverse over the coming decades. We show a model simulation of the expected temperature change over the next two decades (2006-2026). The simulation shows a

  6. Prediction and analysis model of temperature and its application to a natural ventilation multi-span plastic greenhouse equipped with insect-proof screen

    Institute of Scientific and Technical Information of China (English)

    LIU Shu-zhen; HE Yong; ZHANG Yu-bao; MIAO Xiang-wen

    2005-01-01

    The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2ms-1, wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.

  7. Hortisim: a model for greenhouse crops and greenhouse climate

    NARCIS (Netherlands)

    Gijzen, H.; Heuvelink, E.; Challa, H.; Dayan, E.; Marcelis, L.F.M.; Cohen, S.; Fuchs, M.

    1998-01-01

    A combined model for crop production and climate in greenhouses, HORTISIM, was developed. Existing models, developed by several research groups, of various aspects of crop growth and greenhouse climate have been integrated. HORTISIM contains 7 submodels (Weather, Greenhouse Climate, Soil, Crop, Gree

  8. Characters of Temperature Variation and Minimal Temperature Forecast inside of Solar Greenhouse in Winter in Shouguang City of Shandong Province

    Institute of Scientific and Technical Information of China (English)

    Jing YUAN; Shujun LI; Jianyun CUI; Gang QIU; Nan LI

    2012-01-01

    [Objective] The aim was to improve meteorological service of protected agriculture and to reduce effects of meteorological disasters. [Method] Characters of temperature variation in solar greenhouse and minimal temperature forecast models in winter were analyzed based on meteorological data inside and outside of solar greenhouse in winter during 2008-2011, as per correlation and stepwise regression method. [Result] Temperature was of significant changes in solar greenhouse in sunny and cloudy days and the change was higher in sunny days. In overcast days, temperature in solar greenhouse was lower and plants were affected seriously. In addition, the minimal temperature was of good correlation with outside temperature and humidity, temperature and soil temperature in greenhouse. [Conclusion] The minimal temperature forecast model of solar greenhouse is established and the average absolute error of the forecasted minimums in different types of weather was less than 1 ℃ and the average relative error was lower than 10%.

  9. Algorithm of heating temperature for Chongqing's winter greenhouses

    Institute of Scientific and Technical Information of China (English)

    XIE Shou-yong; LI Xi-wen; YANG Shu-zi; YANG Ming-jin

    2007-01-01

    Internal temperature is crucial to plant growth in the greenhouse. We investigated the patterns of constructing and managing greenhouses in Chongqing, and developed an algorithm of heating temperature for closed winter plastic greenhouses under the conditions of no man-made illumination, no ventilation and hot wind machine as the heating equipment, which are the most adopted pattern of greenhouses in Chongqing area. The algorithm includes two functions of temperature outside the greenhouse, which calculate the values of the warming estimation coefficient (WEC) and the gap between temperatures inside and outside the greenhouse with the measured data of outside temperature, and then give the value of internal temperature; the heat rating of heating facilities required by a greenhouse can be determined by this algorithm with given values of floor area and internal temperature, measured outside temperature and calculated WEC. Verification of the algorithm demonstrates a desirable accuracy of estimation. Algorithms of computing heating temperature for greenhouses of different constructing and managing patterns and in different geographic conditions can also be derived in a similar way. This research presents a paradigm for developing a feasible method to fit out greenhouses with appropriate heating facilities, aiming at energy efficient and cost efficient production.

  10. Calibration and validation of an activated sludge model for greenhouse gases no. 1 (ASMG1): prediction of temperature-dependent N₂O emission dynamics.

    Science.gov (United States)

    Guo, Lisha; Vanrolleghem, Peter A

    2014-02-01

    An activated sludge model for greenhouse gases no. 1 was calibrated with data from a wastewater treatment plant (WWTP) without control systems and validated with data from three similar plants equipped with control systems. Special about the calibration/validation approach adopted in this paper is that the data are obtained from simulations with a mathematical model that is widely accepted to describe effluent quality and operating costs of actual WWTPs, the Benchmark Simulation Model No. 2 (BSM2). The calibration also aimed at fitting the model to typical observed nitrous oxide (N₂O) emission data, i.e., a yearly average of 0.5% of the influent total nitrogen load emitted as N₂O-N. Model validation was performed by challenging the model in configurations with different control strategies. The kinetic term describing the dissolved oxygen effect on the denitrification by ammonia-oxidizing bacteria (AOB) was modified into a Haldane term. Both original and Haldane-modified models passed calibration and validation. Even though their yearly averaged values were similar, the two models presented different dynamic N₂O emissions under cold temperature conditions and control. Therefore, data collected in such situations can potentially permit model discrimination. Observed seasonal trends in N₂O emissions are simulated well with both original and Haldane-modified models. A mechanistic explanation based on the temperature-dependent interaction between heterotrophic and autotrophic N₂O pathways was provided. Finally, while adding the AOB denitrification pathway to a model with only heterotrophic N₂O production showed little impact on effluent quality and operating cost criteria, it clearly affected N2O emission productions.

  11. Integrated optimization of temperature, CO2, screen use and artificial lighting in greenhouse crops

    DEFF Research Database (Denmark)

    Aaslyng, J.M.; Körner, O.; Andreassen, A.U.;

    2005-01-01

    A leaf photosynthesis model is suggested for integrated optimization of temperature, CO2, screen use and artificial lighting in greenhouse crops. Three different approaches for the optimization are presented. First, results from greenhouse experiments with model based optimization are presented....... Second, a model-based analysis of a commercial grower's production possibility is shown. Third, results from a simulation of the effect of a new lighting strategy are demonstrated. The results demonstrate that it is possible to optimize plant production by using a model-based integrated optimization...... of temperature, CO2, and light in the greenhouse...

  12. Design of Greenhouse Temperature and Light Intensity Control Circuit

    Institute of Scientific and Technical Information of China (English)

    Chao; ZHANG

    2014-01-01

    In view of domestic scientific and technological achievements at present,real-time control circuit for greenhouse temperature and light intensity has been designed in line with the principle of cost saving and easy control.With advanced temperature sensor and light sensor applied to measure the temperature and light intensity,an execution unit is controlled by single-chip microcomputer(SCM)to regulate the temperature and light intensity,creating a hardware design scheme and software design idea.In case of high temperature and high light intensity in greenhouse,the sunshade net will be put down and the blower will be started automatically;in case of low temperature and light intensity,the sunshade net will be folded up and the heating valve will be turned up automatically.In this way,the temperature and light intensity in greenhouse will be controlled within the designed range.

  13. Greenhouse Modeling Using Continuous Timed Petri Nets

    Directory of Open Access Journals (Sweden)

    José Luis Tovany

    2013-01-01

    Full Text Available This paper presents a continuous timed Petri nets (ContPNs based greenhouse modeling methodology. The presented methodology is based on the definition of elementary ContPN modules which are designed to capture the components of a general energy and mass balance differential equation, like parts that are reducing or increasing variables, such as heat, CO2 concentration, and humidity. The semantics of ContPN is also extended in order to deal with variables depending on external greenhouse variables, such as solar radiation. Each external variable is represented by a place whose marking depends on an a priori known function, for instance, the solar radiation function of the greenhouse site, which can be obtained statistically. The modeling methodology is illustrated with a greenhouse modeling example.

  14. Takagi-Sugeno control of nocturnal temperature in greenhouses using air heating.

    Science.gov (United States)

    Nachidi, M; Rodríguez, F; Tadeo, F; Guzman, J L

    2011-04-01

    A solution to the problem of controlling the minimum temperature in greenhouses using controllers developed from nonlinear models of the system is discussed and applied on a real greenhouse. More precisely, the controllers designed are Takagi-Sugeno type controllers, and the proposed design method is an iterative method based on solving a set of Linear Matrix Inequalities, which ensures stability and performance in closed-loop. The tests in a real greenhouse show that it is possible to design controllers for control of nocturnal temperature that give good performance, and guarantee stability in a wide range of working conditions.

  15. "Home Made" Model to Study the Greenhouse Effect and Global Warming

    Science.gov (United States)

    Onorato, P.; Mascheretti, P.; DeAmbrosis, A.

    2011-01-01

    In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of…

  16. "Home Made" Model to Study the Greenhouse Effect and Global Warming

    Science.gov (United States)

    Onorato, P.; Mascheretti, P.; DeAmbrosis, A.

    2011-01-01

    In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of…

  17. Cuckoo Search Optimization for Reduction of a Greenhouse Climate Model

    Directory of Open Access Journals (Sweden)

    Hasni Abdelhafid

    2016-07-01

    Full Text Available Greenhouse climate and crop models and specially reduced models are necessary for bettering environmental management and control ability. In this paper, we present a new metaheuristic method, called Cuckoo Search (CS algorithm, established on the life of a bird family for selecting the parameters of a reduced model which optimizes their choice by minimizing a cost function. The reduced model was already developed for control purposes and published in the literature. The proposed models target at simulating and predicting the greenhouse environment. [?]. This study focuses on the dynamical behaviors of the inside air temperature and pressure using ventilation. Some experimental results are used for model validation, the greenhouse being automated with actuators and sensors connected to a greenhouse control system on the cuckoo search methods to determine the best set of parameters allowing for the convergence of a criteria based on the difference between calculated and observed state variables (inside air temperature and water vapour pressure content. The results shown that the tested Cuckoo Search algorithm allows for a faster convergence towards the optimal solution than classical optimization methods.

  18. Global comparison of three greenhouse climate models

    NARCIS (Netherlands)

    Bavel, van C.H.M.; Takakura, T.; Bot, G.P.A.

    1985-01-01

    Three dynamic simulation models for calculating the greenhouse climate and its energy requirements for both heating and cooling were compared by making detailed computations for each of seven sets of data. The data sets ranged from a cold winter day, requiring heating, to a hot summer day, requiring

  19. Modeling Greenhouse Gas Emissions from Enteric Fermentation

    NARCIS (Netherlands)

    Kebreab, E.; Tedeschi, L.; Dijkstra, J.; Ellis, J.L.; Bannink, A.; France, J.

    2016-01-01

    Livestock directly contribute to greenhouse gas (GHG) emissions mainly through methane (CH4) and nitrous oxide (N2O) emissions. For cost and practicality reasons, quantification of GHG has been through development of various types of mathematical models. This chapter addresses the utility and limita

  20. 辽西日光温室温度变化规律及温度预测模型%Temperature Variation Rules and Prediction Model of Solar Greenhouse in West Liaoning

    Institute of Scientific and Technical Information of China (English)

    张国林; 宗英飞; 王吉宏

    2013-01-01

    为了设施农业的发展,拓宽农业气象服务范围,减轻低温冷害对日光温室农业生产的影响,利用多年多点日光温室大棚内外气象观测资料,采用相关及温度变化速率分析方法,对日光温室内温度变化特征进行研究并建立预测模型。结果表明,日光温室内气温有明显的日变化和季节变化。不同的天气状况、不同季节产生不同的温变速率,晴天温度速率大于多云及阴天;寒冷期温变速率大于非寒冷期。大棚内温度日变化为“1升2降”,季节变化呈U型。日光温室内外温差随着外界气温的下降而加大,12月-翌年2月呈抛物线型变化。应用棚内温度预测模型,预报2012年2月中旬棚内最低温度,预报值平均绝对误差-0.7℃,平均相对误差-11.4%。%The paper targets at promoting the development of agricultural facilities, expanding the scope of agro-meteorological services, and reducing impact of chilling damage on greenhouse agricultural production. It made researches on the temperature variation in the solar greenhouse and established related predictive models, in accordance with meteorological observation data inside and outside solar greenhouse collected on multiple monitoring sites over the years, by adopting correlation methods and the temperature variation rate analysis methods. It was shown from the results that there appeared significant diurnal and seasonal changes in temperature of solar greenhouse. At different weather conditions and different seasons, the variation rate varied; the temperature variation rate in sunny days was greater than that in cloudy days; the temperature variation rate in cold period was greater than that in non-cold period; the diurnal temperature variation of solar greenhouse was characterized by“one-increasing-factor”and“two-decreasing-factor”, seasonal change presented a“U-shaped”curve. The inside/outside temperature difference of solar

  1. Modeling and control of greenhouse crop growth

    CERN Document Server

    Rodríguez, Francisco; Guzmán, José Luis; Ramírez-Arias, Armando

    2015-01-01

    A discussion of challenges related to the modeling and control of greenhouse crop growth, this book presents state-of-the-art answers to those challenges. The authors model the subsystems involved in successful greenhouse control using different techniques and show how the models obtained can be exploited for simulation or control design; they suggest ideas for the development of physical and/or black-box models for this purpose. Strategies for the control of climate- and irrigation-related variables are brought forward. The uses of PID control and feedforward compensators, both widely used in commercial tools, are summarized. The benefits of advanced control techniques—event-based, robust, and predictive control, for example—are used to improve on the performance of those basic methods. A hierarchical control architecture is developed governed by a high-level multiobjective optimization approach rather than traditional constrained optimization and artificial intelligence techniques.  Reference trajector...

  2. 基于主成分回归的日光温室内低温预测模型%Forecast Model of Minimum Temperature inside Greenhouse Based on Principal Component Regression

    Institute of Scientific and Technical Information of China (English)

    李宁; 申双和; 黎贞发; 李春; 刘淑梅; 薛庆禹

    2013-01-01

    To forecast minimum temperature inside greenhouse,the minimum temperature forecast model was established based on meteorological observation data inside the solar greenhouse in winter of 2010 and 2011,by using of principal component regression.The characteristic of temperature,total cloud cover and maximum wind velocity was discussed through cloud covered coefficient method and standard of wind velocity conversion.The results showed that the simulation errors of cloud cover and wind velocity were reasonable.There was a good correlation between minimum temperature inside the solar greenhouse and microclimate elements in greenhouse last day.Moreover,similar correlation also existed between meteorological elements inside and outside greenhouse.The multiple correlation coefficient of the model was 0.857,and approved by significant testing.The average absolute errors of forecast minimum temperature inside greenhouse in different weather conditions were less than 1 ℃,the average relative errors were within 13%,and the RMSE was 1.1 ℃ during the whole winter by using principal component regression method.The results indicated that minimum temperature forecast model had quite precisely for predicting minimum temperature inside greenhouse,which could meet the forecast requirements for greenhouse microclimate.%利用2010/2011年度冬季日光温室内小气候观测资料对冬季日光温室内温度变化特征进行分析,并结合温室外温度以及用云遮系数法和风级风速转换方法得到的室外总云量和最大风速,采用主成分回归分析法建模,以对日光温室内日最低气温进行预报.结果表明,(1)通过云遮系数法和风速风级转化标准模拟的室外总云量和最大风速误差较小.(2)日光温室内最低气温与温室内前一天的各小气候要素有较好的相关性,此外,温室内外各气象要素之间也存在显著的相关性.(3)主成分回归提取了温室内小气候要素主成分、温室外

  3. Molding and control of greenhouse temperature-humidity system based on grey prediction model%基于灰色预测模型的温室温湿度系统建模与控制

    Institute of Scientific and Technical Information of China (English)

    秦琳琳; 马国旗; 储著东; 吴刚

    2016-01-01

    温室温湿度系统是一个典型的混杂系统(hybrid system,HS),系统的输入包括环境调控设备的开关状态以及可测不可控的外界环境因子扰动输入,包括太阳辐射、室外温度、室外湿度、风速、风向等。针对温室温湿度系统的这种混杂特性,该文提出一种基于切换系统的温室温湿度系统建模与预测控制方法。首先,分别在天窗开启与关闭状态下采用遗忘因子递推最小二乘法(forgetting factor recursive least squares,FFRLS)辨识模型参数,得到系统的2个子系统模型。采用灰色预测 GM(1,1)模型预测温室温室度系统中可测不可控的扰动输入。然后,将系统预测控制问题描述为混合整数二次规划问题(mixed integer quadratic problem,MIQP),并通过分支定界法求解。分析了系统在有限时间内的稳定性(finite time stable,FTS)。最后进行了仿真研究,仿真结果表明该文中提出的建模和控制方法是有效的。%Greenhouse temperature-humidity system can be regarded as a hybrid system, where the discrete variables, i.e. the switching states of environmental control devices, e.g. ventilation window, wet curtain-fan, sunshade nets and et al, and the continuous variables, i.e. greenhouse temperature, humidity, and measurable but uncontrollable disturbance inputs consisting of outside temperature, outside humidity, solar radiation, wind direction, wind speed and et al interact. Besides, what makes the greenhouse temperature-humidity system difficult to control is the existence of the outside measurable but uncontrollable disturbance inputs. As a result, some conventional methods like feedback, feedforward are not applicable to the greenhouse temperature-humidity system. In this paper, according to the hybrid characteristic of greenhouse temperature-humidity system, a method based on switched models was proposed for modelling and predictive control of greenhouse

  4. Greenhouse climate model : an aid to estimate the influence of supplemental lighting on greenhouse climate

    OpenAIRE

    Binotto, Marco 1987

    2012-01-01

    GeoGreenhouse project involves the construction of a greenhouse for growing tomatoes in Iceland. The first stage consists of a gross area of five hectares. Due to the peculiarities of such project and because of the unique weather, a greenhouse climate model is advisable to analyze various design solutions. Iceland's weather has a seasonal change in the length of day and night, creating unique weather phenomena. In midwinter, there is a period where darkness prevails. In midsummer, dayligh...

  5. 'Home made' model to study the greenhouse effect and global warming

    Energy Technology Data Exchange (ETDEWEB)

    Onorato, P; Mascheretti, P; DeAmbrosis, A, E-mail: pasquale.onorato@unipv.it, E-mail: anna.deambrosisvigna@unipv.it [Department of Physics ' A. Volta' , University of Pavia, Via Bassi 6, I-27100 Pavia (Italy)

    2011-03-15

    In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of greenhouse effect and their actual ones. It may also be used to predict the average temperature of the Earth surface in the future, depending on the variations of the concentration of greenhouse gases in the atmosphere due to human activities. This model can promote an elementary understanding of global warming since it allows a simple formalization of the energy balance for the Earth in the stationary condition, in the presence of greenhouse gases. For these reasons it can be introduced in courses for undergraduate physics students and for teacher preparation.

  6. Greenhouse

    Data.gov (United States)

    Federal Laboratory Consortium — PurposeThe greenhouse at ERDC’s Cold Regions Research and Engineering Laboratory (CRREL) is used for germination and root-growth studies to support basic and field...

  7. The contribution of greenhouse gases to the recent slowdown in global-mean temperature trends

    Science.gov (United States)

    Checa-Garcia, R.; Shine, K. P.; Hegglin, M. I.

    2016-09-01

    The recent slowdown in the rate of increase in global-mean surface temperature (GMST) has generated extensive discussion, but little attention has been given to the contribution of time-varying trends in greenhouse gas concentrations. We use a simple model approach to quantify this contribution. Between 1985 and 2003, greenhouse gases (including well-mixed greenhouse gases, tropospheric and stratospheric ozone, and stratospheric water vapour from methane oxidation) caused a reduction in GMST trend of around 0.03-0.05 K decade-1 which is around 18%-25% of the observed trend over that period. The main contributors to this reduction are the rapid change in the growth rates of ozone-depleting gases (with this contribution slightly opposed by stratospheric ozone depletion itself) and the weakening in growth rates of methane and tropospheric ozone radiative forcing. Although CO2 is the dominant greenhouse gas contributor to GMST trends, the continued increase in CO2 concentrations offsets only about 30% of the simulated trend reduction due to these other contributors. These results emphasize that trends in non-CO2 greenhouse gas concentrations can make significant positive and negative contributions to changes in the rate of warming, and that they need to be considered more closely in analyses of the causes of such variations.

  8. Greenhouse climate : from physical processes to a dynamic model

    NARCIS (Netherlands)

    Bot, G.P.A.

    1983-01-01

    In this thesis greenhouse climate has been studied as the set of environmental conditions in a greenhouse in so far as they affect crop growth and development. In chapter 2 this set has been defined in terms of temperatures and vapour pressures. Moreover we have indicated which physical processes

  9. Neural Network Modeling to Predict Shelf Life of Greenhouse Lettuce

    Directory of Open Access Journals (Sweden)

    Wei-Chin Lin

    2009-04-01

    Full Text Available Greenhouse-grown butter lettuce (Lactuca sativa L. can potentially be stored for 21 days at constant 0°C. When storage temperature was increased to 5°C or 10°C, shelf life was shortened to 14 or 10 days, respectively, in our previous observations. Also, commercial shelf life of 7 to 10 days is common, due to postharvest temperature fluctuations. The objective of this study was to establish neural network (NN models to predict the remaining shelf life (RSL under fluctuating postharvest temperatures. A box of 12 - 24 lettuce heads constituted a sample unit. The end of the shelf life of each head was determined when it showed initial signs of decay or yellowing. Air temperatures inside a shipping box were recorded. Daily average temperatures in storage and averaged shelf life of each box were used as inputs, and the RSL was modeled as an output. An R2 of 0.57 could be observed when a simple NN structure was employed. Since the "future" (or remaining storage temperatures were unavailable at the time of making a prediction, a second NN model was introduced to accommodate a range of future temperatures and associated shelf lives. Using such 2-stage NN models, an R2 of 0.61 could be achieved for predicting RSL. This study indicated that NN modeling has potential for cold chain quality control and shelf life prediction.

  10. The effect of low ancient greenhouse climate temperature gradients on the ocean's overturning circulation

    Directory of Open Access Journals (Sweden)

    W. P. Sijp

    2015-10-01

    Full Text Available We examine whether the reduced meridional temperature gradients of past greenhouse climates might have reduced oceanic overturning, leading to a more quiescent subsurface ocean. A substantial reduction of the pole to equator temperature difference is achieved in a coupled climate model via an altered radiative balance in the atmosphere. Contrary to expectations, we find that the meridional overturning circulation and deep ocean kinetic energy remain relatively unaffected. Reducing the wind strength also has remarkably little effect on the overturning. Instead, overturning strength depends on deep ocean density gradients, which remain relatively unaffected by the surface changes, despite an overall decrease in ocean density. Ocean poleward heat transport is significantly reduced only in the Northern Hemisphere, as now the circulation operates across a reduced temperature gradient, suggesting the overturning circulation dominates heat transport in greenhouse climates. These results indicate that climate models of the greenhouse climate during the Cretaceous and early Paleogene may yield a reasonable overturning circulation, despite failing to fully reproduce the extremely reduced temperature gradients of those time periods.

  11. Physics-based model for a water-saving greenhouse

    NARCIS (Netherlands)

    Speetjens, S.L.; Stigter, J.D.; Straten, van G.

    2010-01-01

    A new greenhouse type has been designed to study ways of decreasing water use by horticulture in semi-arid regions. To control the greenhouse a model-based control design is required. To this end a model is needed to predict the systems behaviour (1 day ahead), without much computational effort. A

  12. A methodology for model-based greenhouse design: Part 1, a greenhouse climate model for a broad range of designs and climates

    NARCIS (Netherlands)

    Vanthoor, B.H.E.; Stanghellini, C.; Henten, van E.J.; Visser, de P.H.B.

    2011-01-01

    With the aim of developing a model-based method to design greenhouses for a broad range of climatic and economic conditions, a greenhouse climate model has been developed and validated. This model describes the effects of the outdoor climate and greenhouse design on the indoor greenhouse climate. Fo

  13. STRATOSPHERIC TEMPERATURES AND WATER LOSS FROM MOIST GREENHOUSE ATMOSPHERES OF EARTH-LIKE PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Kasting, James F.; Kopparapu, Ravi K. [Department of Geosciences, The Pennsylvania State University, State College, PA 16801 (United States); Chen, Howard, E-mail: jfk4@psu.edu, E-mail: hwchen@bu.edu [Department of Astronomy, Boston University, 725 Commonwealth Ave., Boston, MA 02215 (United States)

    2015-11-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a moist greenhouse explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing inverse climate calculations to determine habitable zone boundaries using 1D models.

  14. Stratospheric Temperatures and Water Loss from Moist Greenhouse Atmospheres of Earth-like Planets

    CERN Document Server

    Kasting, James F; Kopparapu, Ravi Kumar

    2015-01-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3-D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a 'moist greenhouse' explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing 'inverse' climate calculations to determine habitable zone boundaries using 1-D models.

  15. A methodology for model-based greenhouse design: Part 3, sensitivity analysis of a combined greenhouse climate-crop yield model

    NARCIS (Netherlands)

    Vanthoor, B.H.E.; Henten, van E.J.; Stanghellini, C.; Visser, de P.H.B.

    2011-01-01

    Greenhouse design is an optimisation problem that might be solved by a model-based greenhouse design method. A sensitivity analysis of a combined greenhouse climate-crop yield model of tomato was done to identify the parameters, i.e. greenhouse design parameters, outdoor climate and climate set-poin

  16. Identifcation of a Linear COntinuous Time Stochastic Model of the Heat Dynamics of a Greenhouse

    DEFF Research Database (Denmark)

    Nielsen, Bjarne; Madsen, Henrik

    1998-01-01

    The purpose of this paper is to describe the basis for improving the control of air temperature and heat supply in greenhouses using a method which controls the energy supply by a model-based prediction of the air temperature in the greenhouse. Controllers of this type are the minimum variance co...... controller, the generalized predictive controller and the proportional-integral-plus(PIP) controller. Prediction-based controllers have proved to be powerful in controlling the supply temperature in a distinct heating system....

  17. The Extension of the RAINS Model to Greenhouse Gases

    OpenAIRE

    Klaassen, G.; AMANN, M; Berglund, C; J. Cofala; Hoeglund-Isaksson, L.; Heyes, C.; MECHLER R.; Tohka, A.; W. Schoepp; Winiwarter, W.

    2004-01-01

    Many of the traditional air pollutants and greenhouse gases have common sources, offering a cost-effective potential for simultaneous improvements for both traditional air pollution problems as well as climate change. A methodology has been developed to extend the RAINS integrated assessment model to explore synergies and trade-offs between the control of greenhouse gases and air pollution. With this extension, the RAINS model allows now the assessment of emission control costs for the six gr...

  18. Determination of low-temperature and frost damage indicators and construction of a temperature forecasting model for tomato in greenhouse%日光温室番茄低温冻害指标确定及温度预报模型建立

    Institute of Scientific and Technical Information of China (English)

    张淑杰; 孙立德; 马成芝; 张菁; 陈艳秋; 李广霞; 韩秀君; 吴曼丽; 郭海

    2016-01-01

    利用2012年12月至2013年1月和2013年12月至2014年1月两个生长季沈阳和喀左地区日光温室的小气候观测数据,基于日光温室番茄实际低温冻害发生及影响因素分析,构建日温差指数,确定辽宁地区日光温室番茄果实膨大期低温冻害的指标,并采用回归分析方法建立了日光温室温度预报模型。结果表明:日光温室内持续低温、寡照及高湿综合作用造成了番茄低温冻害的发生。在日光温室内高湿的环境条件下,日光温室外出现阴雨雪天气,且寡照天气持续3 d,日光温室内最高气温小于10℃,最低气温小于5℃,且5℃以下低温持续时间达15 h以上时,将出现低温冻害。利用日光温室内外逐时气温数据建立温室内逐时气温预报模型,18时至翌日08时逐时气温≤3℃误差的预报准确率达86%以上。因此,利用确定的日光温室内番茄低温冻害指标和建立的日光温室内逐时气温预报模型,可实现温室内番茄低温冻害预警,提高日光温室防灾减灾能力。%Based on greenhouse microclimate observation data in two growing seasons from December 2012 to Jan-uary 2013 and from December 2013 to January 2014,the occurrence of frost damage for tomatoes in greenhouse and their influencing factors were analyzed.The diurnal temperature difference index was constructed and taken as an indicator for the happening of low-temperature and frost damage during fruit enlargement period for tomato in greenhouse.Additionally,a temperature forecasting model was constructed through a regression analysis method. The results show that the occurrence of low-temperature and frost damage for tomato in greenhouse can be attribu-ted to the combined effects of continuous low temperature,lack of sunshine and high humidity in greenhouse.Low-temperature and frost damage happens when the number of scant-sunshine days with rain or snow outside green-house is more than 3

  19. A 2nd generation static model for predicting greenhouse energy inputs, as an aid for production planning

    CERN Document Server

    Jolliet, O; Munday, G L

    1985-01-01

    A model which allows accurate prediction of energy consumption of a greenhouse is a useful tool for production planning and optimisation of greenhouse components. To date two types of model have been developed; some very simple models of low precision, others, precise dynamic models unsuitable for employment over long periods and too complex for use in practice. A theoretical study and measurements at the CERN trial greenhouse have allowed development of a new static model named "HORTICERN", easy to use and as precise as more complex dynamic models. This paper demonstrates the potential of this model for long-term production planning. The model gives precise predictions of energy consumption when given greenhouse conditions of use (inside temperatures, dehumidification by ventilation, …) and takes into account local climatic conditions (wind radiative losses to the sky and solar gains), type of greenhouse (cladding, thermal screen …). The HORTICERN method has been developed for PC use and requires less...

  20. Influence of temperature and soil drying on respiration of individual roots in citrus: integrating greenhouse observations into a predictive model for the field

    NARCIS (Netherlands)

    Bryla, D.R.; Bouma, T.J.; Hartmond, U.; Eissenstat, D.M.

    2001-01-01

    In citrus, the majority of fine roots are distributed near the soil surface - a region where conditions are frequently dry and temperatures fluctuate considerably. To develop a better understanding of the relationship between changes in soil conditions and a plant's below-ground respiratory costs,

  1. 宿州日光温室内部最高和最低气温的预报模型%Forecast Model of the Highest and Lowest Temperature in the Sunlight Greenhouse in Suzhou

    Institute of Scientific and Technical Information of China (English)

    李德; 张学贤; 祁宦; 张丙振

    2013-01-01

    Based on temperature data monitored inside the greenhouse and the corresponding surface meteorological observation data, authors established a forecasting model for the highest and lowest temperature in the sunlight greenhouse in autumn, as well as in the sunny and overcast sky separately in winter and spring, by means of stepwise regression method. The models were also tested in the application. The results showed that the absolute error ( ABSE) of the highest and lowest temperatures between the simulated values and the actual values were separately 1. 1 and 0. 2℃ in autumn,0. 8 and 0.4℃ in the sunny day in winter, 1. 5 and 0. 3℃ in the overcast sky in winter,0. 3 and 0.4℃ in the sunny day in spring,1. 1 and 0. 2℃ in the overcast sky in spring. The root mean square error( RMSE) were separately 1. 3 and 0. 2℃ in autumn, 1. 0 and 0. 5℃ in the sunny day in winter, 1. 7 and 0. 3℃ in the overcast sky in winter,0. 3 and 1. 3℃ in the sunny day in spring,0. 4 and 0. 5℃ in the overcast sky in spring. The ABSE of the highest and lowest temperatures between the simulated values and the actual values in autumn were separately 0. 8 - 1. 1℃ and 0. 3 -0. 4℃ and the root mean square error were 0. 9 - 1. 2℃ and 0. 3 -0. 5℃ in the examination. This forecast model which can be used to predict the highest and lowest temperatures in future 24 hours inside the sunlight greenhouse, can provide effective decision support for timely ventilation in greenhouse to prevent high temperature as well as for heat insulation measures to prevent cold harm.%利用2010年11月-2011年5月在日光温室内部监测的温度数据和同期地面气象观测资料,采用逐步回归方法,建立秋季日光温室内部最高与最低气温预报模型,冬季和春季晴天与非晴天日光温室内部最高与最低气温预报模型,并进行应用试验.结果表明,各预报模型的模拟值与实测值之间高温和低温的绝对误差(ABSe)分别为秋季为1.1、0

  2. Modelo de simulação da temperatura e umidade relativa do ar no interior de estufa plástica Simulation model of air temperature and relative humidity in to plastic greenhouses

    Directory of Open Access Journals (Sweden)

    Edilson Costa

    2004-04-01

    Full Text Available A simulação dos parâmetros climáticos de temperatura e umidade relativa do ar no interior de uma estufa plástica, por meio do balanço de energia, pode propiciar ao produtor uma ferramenta de auxílio na tomada de decisão. Nesse propósito, realizou-se uma simulação das condições no interior de estufa plástica, em função de parâmetros externos e internos a ela. A simulação revelou uma temperatura no interior da estufa plástica de 23,6 ºC, e os sensores revelaram um valor médio de 24,1 ºC para o período de cultivo da alface. Para a umidade relativa no interior da estufa plástica, o valor simulado foi de 61,6%, e o obtido com o auxílio de sensores foi de 66,0%. Os valores simulados apresentaram-se próximos dos valores obtidos pelos sensores, mostrando que o modelo pode ser usado para a estimativa da temperatura e umidade relativa do ar no interior da estufa plástica.Simulation of climatic parameters inside air temperature and relative humidity of plastic greenhouse, trough energy balance, allows to growers a good technical tool on the decision making to improve the performance of inside environments. A simulation of internal conditions based on external and internal parameters was evaluated. The results showed the inside mean temperature of 23.6 ºC in comparison with the experimental value of 24.1 ºC, for the cultivated period. The simulated relative humidity presented a value of 61.6% against 66.0% obtained by the sensors. The simulated values were closed to the values obtained by the sensors, which means that the model can be used to determine the internal conditions of plastic greenhouses.

  3. Seventh Grade Students' Mental Models of the Greenhouse Effect

    Science.gov (United States)

    Shepardson, Daniel P.; Choi, Soyoung; Niyogi, Dev; Charusombat, Umarporn

    2011-01-01

    This constructivist study investigates 225 student drawings and explanations from three different schools in the midwest in the US, to identify seventh grade students' mental models of the greenhouse effect. Five distinct mental models were derived from an inductive analysis of the content of the students' drawings and explanations: Model 1, a…

  4. Mesoscale climatic simulation of surface air temperature cooling by highly reflective greenhouses in SE Spain.

    Science.gov (United States)

    Campra, Pablo; Millstein, Dev

    2013-01-01

    A long-term local cooling trend in surface air temperature has been monitored at the largest concentration of reflective greenhouses in the world, at the Province of Almeria, SE Spain, associated with a dramatic increase in surface albedo in the area. The availability of reliable long-term climatic field data at this site offers a unique opportunity to test the skill of mesoscale meteorological models describing and predicting the impacts of land use change on local climate. Using the Weather Research and Forecast (WRF) mesoscale model, we have run a sensitivity experiment to simulate the impact of the observed surface albedo change on monthly and annual surface air temperatures. The model output showed a mean annual cooling of 0.25 °C associated with a 0.09 albedo increase, and a reduction of 22.8 W m(-2) of net incoming solar radiation at surface. Mean reduction of summer daily maximum temperatures was 0.49 °C, with the largest single-day decrease equal to 1.3 °C. WRF output was evaluated and compared with observations. A mean annual warm bias (MBE) of 0.42 °C was estimated. High correlation coefficients (R(2) > 0.9) were found between modeled and observed values. This study has particular interest in the assessment of the potential for urban temperature cooling by cool roofs deployment projects, as well as in the evaluation of mesoscale climatic models performance.

  5. Modelling and Simulation for Energy Production Parametric Dependence in Greenhouses

    Directory of Open Access Journals (Sweden)

    Maurizio Carlini

    2010-01-01

    Full Text Available Greenhouses crops in Italy are made by using prefabricated structures, leaving out the preliminary study of optical and thermal exchanges between the external environment and the greenhouse, dealing with heating and cooling and the effects of air conditioning needed for plant growth. This involves rather significant costs that directs the interest of designers, builders, and farmers in order to seek constructive solutions to optimize the system of such emissions. This work was done by building a model of gases using TRNSYS software, and these gases then have been checked for compliance. The model was constructed considering an example of a prefabricated greenhouse, located in central of Italy. Aspects of the structural components, and thermal and optical properties are analyzed in order to achieve a representation of reality.

  6. Global warming description using Daisyworld model with greenhouse gases.

    Science.gov (United States)

    Paiva, Susana L D; Savi, Marcelo A; Viola, Flavio M; Leiroz, Albino J K

    2014-11-01

    Daisyworld is an archetypal model of the earth that is able to describe the global regulation that can emerge from the interaction between life and environment. This article proposes a model based on the original Daisyworld considering greenhouse gases emission and absorption, allowing the description of the global warming phenomenon. Global and local analyses are discussed evaluating the influence of greenhouse gases in the planet dynamics. Numerical simulations are carried out showing the general qualitative behavior of the Daisyworld for different scenarios that includes solar luminosity variations and greenhouse gases effect. Nonlinear dynamics perspective is of concern discussing a way that helps the comprehension of the global warming phenomenon. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. A photometric model for predicting the sky glow of greenhouses

    NARCIS (Netherlands)

    Alferdinck, J.W.A.M.; Janssen, E.G.O.N.; Zonneveldt, L.; Ruigrok, J.

    2006-01-01

    many greenhouses use artificial light to grow plants. Part of this light escapes, scatters in the sky and causes sky glow. Residents in the vicinity complain about the absence of natural darkness. A light scatter model is developed in order to quantify the dose of the sky glow. The luminance of the

  8. Fuzzy logic technology for modeling of greenhouse crop transpiration rate

    Science.gov (United States)

    Deng, Lujuan; Wang, Huaishan

    2006-11-01

    The objective of this paper was present a reasonable greenhouse crop transpiration rate model for irrigation scheduling thereby to achieve the best effect, for example, water and energy economizing furthermore to make crop growing better. So it was essential to measure crop transpiration rate. Owing to the difficulty of obtaining accurate real time data of crop transpiration, it was commonly estimated from weather parameters. So the fuzzy logic model for estimation of greenhouse crop transpiration rate was developed. The model was made up of five sub-systems and three layers. There were nine input variables and one output variable. The results of comparison between measured and fuzzy model is inspirer. The squared correlation coefficient (r2) by fuzzy model method (r2=0.9302) is slightly higher than by FAO Penman-Monteith formula (r2=0.9213). The fuzzy logic crop transpiration rate model could be easily extended for irrigation decision-making.

  9. Modeling and experimental validation of heat transfer and energy consumption in an innovative greenhouse structure

    Directory of Open Access Journals (Sweden)

    Morteza Taki

    2016-09-01

    Full Text Available The commercial greenhouse is one of the most effective cultivation methods with a yield per cultivated area up to 10 times more than free land cultivation but the use of fossil fuels in this production field is very high. The objectives of this paper are to modeling and experimental evaluation of heat and mass transfer functions in an innovative solar greenhouse with thermal screen. For this propose, a semi-solar greenhouse was designed and constructed at the North-West of Iran in Azerbaijan Province (38°10′N and 46°18′E with elevation of 1364 m above the sea level. The inside environment factors include inside air temperature below screen (Ta, inside air temperature above screen (Tas, crop temperature (Tc, inside soil temperature (Ts, cover temperature (Tri and thermal screen temperature (Tsc were collected as the experimental data samples. The dynamic heat and mass transfer model used to estimate the temperature in six different points of the semi-solar greenhouse with initial values and consider the crop evapotranspiration. The results showed that dynamic model can predict the inside temperatures in four different points (Ta, Tc, Tri, Ts with MAPE, RMSE and EF about 5–7%, 1–2 °C and 80–91% for greenhouse without thermal screen and about 3–7%, 0.6–1.8 °C and 89–96% for six different points of greenhouse with thermal screen (Ta, Tc, Tri, Ts, Tas, Tsc, respectively. The results of using thermal screen at night (12 h in autumn showed that this method can decrease the use of fossil fuels up to 58% and so decrease the final cost and air pollution. This movable insulation caused about 15 °C difference between outside and inside air temperature and also made about 6 °C difference between Ta and Tas. The experimental results showed that inside thermal screen can decrease the crop temperature fluctuation at night.

  10. Analysis and design of greenhouse temperature control using adaptive neuro-fuzzy inference system

    Directory of Open Access Journals (Sweden)

    Doaa M. Atia

    2017-05-01

    Full Text Available The greenhouse is a complicated nonlinear system, which provides the plants with appropriate environmental conditions for growing. This paper presents a design of a control system for a greenhouse using geothermal energy as a power source for heating system. The greenhouse climate control problem is to create a favourable environment for the crop in order to reach predetermined results for high yield, high quality and low costs. Four controller techniques; PI control, fuzzy logic control, artificial neural network control and adaptive neuro-fuzzy control are used to adjust the greenhouse indoor temperature at the required value. MATLAB/SIMULINK is used to simulate the different types of controller techniques. Finally a comparative study between different control strategies is carried out.

  11. Simple model of photo acoustic system for greenhouse effect

    CERN Document Server

    Fukuhara, Akiko; Ogawa, Naohisa

    2010-01-01

    The simple theoretical basis for photo acoustic (PA) system for studying infrared absorption properties of greenhouse gases is constructed. The amplitude of sound observed in PA depends on the modulation frequency of light pulse. Its dependence can be explained by our simple model. According to this model, sound signal has higher harmonics. The theory and experiment are compared in third and fifth harmonics by spectrum analysis. The theory has the analogy with electric circuits. This analogy helps students for understanding the PA system.

  12. 基于CFD的温室气温时空变化预测模型及通风调控措施%Prediction model on temporal and spatial variation of air temperature in greenhouse and ventilation control measures based on CFD

    Institute of Scientific and Technical Information of China (English)

    任守纲; 杨薇; 王浩云; 薛卫; 徐焕良; 熊迎军

    2015-01-01

    夏季温室高温湿热,对作物生长产生重大危害,制定合理的夏季温室气温调控方案,是提高温室生产效益,降低温室气温调控能耗的关键问题。该文基于计算流体力学(computational fluid dynamics,CFD)方法,结合气象预报信息,针对苏南地区大型连栋温室,建立了夏季温室气温时空变化预测模型,通过设置边界参数,对不同通风条件下温室气温的时空变化进行了预测,并通过试验验证了模型的有效性。试验结果表明,预测值与实测值吻合良好,均方根误差在1.2℃以内,最大相对误差在6%以内,平均相对误差在4%以内。不同通风降温条件下的试验结果显示,温室气温空间分布存在明显差异,湿帘-风机系统较自然通风降温效果显著,降温幅度在5℃左右,持续的湿帘-风机降温措施可将温室高温控制在较低水平。基于该文模型的预测结果和温室调控目标,选取合适的时间点、时间长度和不同类型的通风降温措施,可有效提高温室气温调控效率和效益。同时,该研究还可为优化传感器布局提供依据。%Hot and humid environment inside greenhouse in summer is a major threat to crop growth. How to make reasonable control schemes of greenhouse air temperature in summer is the key to improve the greenhouse production efficiency and reduce the energy consumption. In this study, we established a prediction model on temporal and spatial variation of air temperature in greenhouse based on the computational fluid dynamics (CFD) method and meteorology forecast information. The prediction model was adapted to the large multi-span plastic greenhouse in the southern regions of Jiangsu under the natural ventilation and fan-pad cooling system. It can predict the spatial and temporal distribution of greenhouse air temperature under different ventilation cooling conditions. The numerical computation of this

  13. Modeling and (adaptive) control of greenhouse climates

    NARCIS (Netherlands)

    Udink ten Cate, A.J.

    1983-01-01

    The material presented in this thesis can be grouped around four themes, system concepts, modeling, control and adaptive control. In this summary these themes will be treated separately.

    System concepts

    In Chapters 1 and 2 an overview of the problem formulation

  14. Modelling and (adaptive) control of greenhouse climates

    NARCIS (Netherlands)

    Udink ten Cate, A.J.

    1983-01-01

    The material presented in this thesis can be grouped around four themes, system concepts, modeling, control and adaptive control. In this summary these themes will be treated separately.System conceptsIn Chapters 1 and 2 an overview of the problem formulation is presented. It is suggested that there

  15. The clear-sky greenhouse effect sensitivity to a sea surface temperature change

    Science.gov (United States)

    Duvel, J. PH.; Breon, F. M.

    1991-01-01

    The clear-sky greenhouse effect response to a sea surface temperature (SST or Ts) change is studied using outgoing clear-sky longwave radiation measurements from the Earth Radiation Budget Experiment. Considering geographical distributions for July 1987, the relation between the SST, the greenhouse effect (defined as the outgoing infrared flux trapped by atmospheric gases), and the precipitable water vapor content (W), estimated by the Special Sensor Microwave Imager, is analyzed first. A fairly linear relation between W and the normalized greenhouse effect g, is found. On the contrary, the SST dependence of both W and g exhibits nonlinearities with, especially, a large increase for SST above 25 C. This enhanced sensitivity of g and W can be interpreted in part by a corresponding large increase of atmospheric water vapor content related to the transition from subtropical dry regions to equatorial moist regions. Using two years of data (1985 and 1986), the normalized greenhouse effect sensitivity to the sea surface temperature is computed from the interannual variation of monthly mean values.

  16. Evaluation of heat transfer mathematical models and multiple linear regression to predict the inside variables in semi-solar greenhouse

    Directory of Open Access Journals (Sweden)

    M Taki

    2017-05-01

    Full Text Available Introduction Controlling greenhouse microclimate not only influences the growth of plants, but also is critical in the spread of diseases inside the greenhouse. The microclimate parameters were inside air, greenhouse roof and soil temperature, relative humidity and solar radiation intensity. Predicting the microclimate conditions inside a greenhouse and enabling the use of automatic control systems are the two main objectives of greenhouse climate model. The microclimate inside a greenhouse can be predicted by conducting experiments or by using simulation. Static and dynamic models are used for this purpose as a function of the metrological conditions and the parameters of the greenhouse components. Some works were done in past to 2015 year to simulation and predict the inside variables in different greenhouse structures. Usually simulation has a lot of problems to predict the inside climate of greenhouse and the error of simulation is higher in literature. The main objective of this paper is comparison between heat transfer and regression models to evaluate them to predict inside air and roof temperature in a semi-solar greenhouse in Tabriz University. Materials and Methods In this study, a semi-solar greenhouse was designed and constructed at the North-West of Iran in Azerbaijan Province (geographical location of 38°10′ N and 46°18′ E with elevation of 1364 m above the sea level. In this research, shape and orientation of the greenhouse, selected between some greenhouses common shapes and according to receive maximum solar radiation whole the year. Also internal thermal screen and cement north wall was used to store and prevent of heat lost during the cold period of year. So we called this structure, ‘semi-solar’ greenhouse. It was covered with glass (4 mm thickness. It occupies a surface of approximately 15.36 m2 and 26.4 m3. The orientation of this greenhouse was East–West and perpendicular to the direction of the wind prevailing

  17. Children's Models of Understanding of Two Major Global Environmental Issues (Ozone Layer and Greenhouse Effect).

    Science.gov (United States)

    Boyes, Edward; Stanisstreet, Martin

    1997-01-01

    Aims to quantify the models that 13- and 14 year-old students hold about the causes of the greenhouse effect and ozone layer depletion. Assesses the prevalence of those ideas that link the two phenomena. Twice as many students think that holes in the ozone layer cause the greenhouse effect than think the greenhouse effect causes ozone depletion.…

  18. Children's Models of Understanding of Two Major Global Environmental Issues (Ozone Layer and Greenhouse Effect).

    Science.gov (United States)

    Boyes, Edward; Stanisstreet, Martin

    1997-01-01

    Aims to quantify the models that 13- and 14 year-old students hold about the causes of the greenhouse effect and ozone layer depletion. Assesses the prevalence of those ideas that link the two phenomena. Twice as many students think that holes in the ozone layer cause the greenhouse effect than think the greenhouse effect causes ozone depletion.…

  19. Greenhouse Effect: Temperature of a Metal Sphere Surrounded by a Glass Shell and Heated by Sunlight

    Science.gov (United States)

    Nguyen, Phuc H.; Matzner, Richard A.

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the "z"-axis. This development is a generalization of the simple treatment of the…

  20. A 2nd generation static model of greenhouse energy requirements (horticern) : a comparison with dynamic models

    CERN Document Server

    Jolliet, O; Munday, G L

    1989-01-01

    Optimisation of a greenhouse and its components requires a suitable model permitting precise determination of its energy requirements. Existing static models are simple but lack precision; dynamic models though more precise, are unsuitable for use over long periods and difficult to handle in practice. A theoretical study and measurements from the CERN trial greenhouse have allowed the development of new static model named "HORTICERN", precise and easy to use for predicting energy consumption and which takes into account effects of solar energy, wind and radiative loss to the sky. This paper compares the HORTICERN model with the dynamic models of Bot, Takakura, Van Bavel and Gembloux, and demonstrates that its precision is comparable; differences on average being less than 5%, it is independent of type of greenhouse (e.g. single or double glazing, Hortiplus, etc.) and climate. The HORTICERN method has been developed for PC use and is proving to be a powerful tool for greenhouse optimisation by research work...

  1. Modeling of global surface air temperature

    Science.gov (United States)

    Gusakova, M. A.; Karlin, L. N.

    2012-04-01

    A model to assess a number of factors, such as total solar irradiance, albedo, greenhouse gases and water vapor, affecting climate change has been developed on the basis of Earth's radiation balance principle. To develop the model solar energy transformation in the atmosphere was investigated. It's a common knowledge, that part of the incoming radiation is reflected into space from the atmosphere, land and water surfaces, and another part is absorbed by the Earth's surface. Some part of outdoing terrestrial radiation is retained in the atmosphere by greenhouse gases (carbon dioxide, methane, nitrous oxide) and water vapor. Making use of the regression analysis a correlation between concentration of greenhouse gases, water vapor and global surface air temperature was obtained which, it is turn, made it possible to develop the proposed model. The model showed that even smallest fluctuations of total solar irradiance intensify both positive and negative feedback which give rise to considerable changes in global surface air temperature. The model was used both to reconstruct the global surface air temperature for the 1981-2005 period and to predict global surface air temperature until 2030. The reconstructions of global surface air temperature for 1981-2005 showed the models validity. The model makes it possible to assess contribution of the factors listed above in climate change.

  2. A methodology for model-based greenhouse design: Part 5, greenhouse design optimisation for southern-Spanish and Dutch conditions

    NARCIS (Netherlands)

    Vanthoor, B.H.E.; Stigter, J.D.; Henten, van E.J.; Stanghellini, C.; Visser, de P.H.B.; Hemming, S.

    2012-01-01

    An optimisation algorithm, as an essential part of a model-based method to design greenhouses for a broad range of climatic and economic conditions, was described. This algorithm – a modified controlled random search using parallel computing – maximised the annual Net Financial Return (NFR) for a to

  3. A methodology for model-based greenhouse design: Part 5, greenhouse design optimisation for southern-Spanish and Dutch conditions

    NARCIS (Netherlands)

    Vanthoor, B.H.E.; Stigter, J.D.; Henten, van E.J.; Stanghellini, C.; Visser, de P.H.B.; Hemming, S.

    2012-01-01

    An optimisation algorithm, as an essential part of a model-based method to design greenhouses for a broad range of climatic and economic conditions, was described. This algorithm – a modified controlled random search using parallel computing – maximised the annual Net Financial Return (NFR) for a

  4. Evolving Greenhouses : An Agent-Based Model of Universal Darwinism in Greenhouse Horticulture

    NARCIS (Netherlands)

    Kasmire, J.; Nikolic, Igor; Dijkema, Gerard

    2013-01-01

    To explore the space between the theories of the Diffusion of Innovations and Universal Darwinism, we first examine a case study of the history of the greenhouse horticulture sector of the Netherlands, comparing and contrasting the narrow focus of Diffusion of Innovations and the wider focus of Univ

  5. Simple greenhouse climate model as a design tool for greenhouses in tropical lowland

    NARCIS (Netherlands)

    Impron, I.; Hemming-Hoffmann, S.; Bot, G.P.A.

    2007-01-01

    Six prototypes plastic greenhouses were built in the tropical lowlands of Indonesia. The geometrical dimensions were designed using computational fluid dynamics (CFD) by taking local climate parameters as static reference boundary conditions. It is necessary to evaluate the climate dynamics inside

  6. Assessment the Effects of Temperature and Humidity Control in Greenhouse Cucumber Productions in Jiroft and Kahnooj Region

    Directory of Open Access Journals (Sweden)

    D Momeni

    2012-05-01

    Full Text Available Temperature and humidity are two important parameters affecting the quality and quantity of greenhouse products so two double greenhouses were manufactured in 3.5, 40 and 11 m in height, length and width respectively in agricultural research center of jiroft and kahnooj to study these effects. Both of greenhouses are similar in materials, final height, gutter height, covering and field operation but in one of them one heating system, two ventilation fans and one wooden pad were assembled and temperature and humidity besides yield were registered in both of them. The results showed that temperature changing trend inside and outside of the unheated greenhouse were in same phase and this isn't suitable in cold night so the greenhouse with heating system had more yield and picking cucumber fruit numbers than another. Therefore it is necessary to be heated by artificial systems. Because of rapid relative humidity changing in outside of greenhouse in the end of the season, the efficiency of fan and pads cooling system is so low then using of evaporating cooling systems such as fans and pad wasn't proposed and recommend to optimize the temperature by ventilation and shading the greenhouse and in hot days production will be cut.

  7. Performance Analysis of a Greenhouse Fan-Pad Cooling System: Gradients of Horizontal Temperature and Relative Humidity

    OpenAIRE

    DAYIOĞLU, Mehmet Ali

    2014-01-01

    An experimental study was conducted to determine the performance parameters of system, as well as gradients of temperature and humidity along greenhouse when opening fan-ped cooling system. Measurements related with greenhouse environment were carried out by using seven sensors for different locations, as well as portable instruments. For this purpose, the five digital temperature and humidity sensors and two pyranometers were used during experiments. Among them, two were located outside gree...

  8. Differences between the glacial cycles of Antarctic temperature and greenhouse gases

    Directory of Open Access Journals (Sweden)

    A. W. Omta

    2012-03-01

    Full Text Available Ice-core measurements have indicated that the atmospheric concentrations of the greenhouse gases CO2 and CH4 show glacial-interglacial variations in step with Antarctic temperature. To obtain more insight into the nature of this relationship for cycles of different frequencies, measured time series of temperature, CO2, and CH4 are reanalysed. The results indicate that the temperature signal consists of a linear superposition of a component related to CO2 with a period of ~100 000 yr and a component related to variations in the obliquity of the Earth's orbital plane with a period of ~41 000 yr. This suggests that either there operate very different feedback mechanisms at the different time scales or that CO2 is not merely a~passive follower and amplifier of the glacial-interglacial variations in Antarctic temperature.

  9. Effects of plant size, temperature, and light intensity on flowering of Phalaenopsis hybrids in Mediterranean greenhouses.

    Science.gov (United States)

    Paradiso, Roberta; De Pascale, Stefania

    2014-01-01

    Mediterranean greenhouses for cultivation of Phalaenopsis orchids reproduce the warm, humid, and shaded environment of tropical underbrush. Heating represents the highest production cost, due to the high thermal requirements and the long unproductive phase of juvenility, in which plants attain the critical size for flowering. Our researches aimed to investigate the effect of plant size, temperature, and light intensity, during the phase of flower induction, on flowering of modern genotypes selected for Mediterranean greenhouses. Three experiments were carried out to compare (i) plant size: reduced size versus size considered optimal for flowering (hybrids "Sogo Yukidian," "Chain Xen Diamond," and "Pinlong"); (ii) temperature: moderate reduction of temperature versus standard thermal regime (hybrid "Premium"); (iii) light intensity: supplemental lighting versus reference light intensity (hybrid "Premium"). The premature exposure of plants to the inductive treatment delayed the beginning of flowering and reduced the flower stem quality, in all the tested hybrids. In "Premium," the lower temperature did not affect flowering earliness and commercial quality of flower stems compared to the standard regime, whereas it promoted stem branching. In the same hybrid, supplemental lighting anticipated flowering and promoted the emission of the second stem and the stem branching, compared to the reference light regime.

  10. Photosynthesis driven crop growth models for greenhouse cultivation; advances and bottlenecks.

    NARCIS (Netherlands)

    Challa, H.; Heuvelink, E.

    1996-01-01

    In recent years considerable progress has been made in modelling growth of green-house crops. Nevertheless, the share of research in this field compared to crop modelling in general is only a few percent. Yet, crop growth models have a great potential for greenhouse production systems, because they

  11. Greenhouse gases from wastewater treatment - A review of modelling tools.

    Science.gov (United States)

    Mannina, Giorgio; Ekama, George; Caniani, Donatella; Cosenza, Alida; Esposito, Giovanni; Gori, Riccardo; Garrido-Baserba, Manel; Rosso, Diego; Olsson, Gustaf

    2016-05-01

    Nitrous oxide, carbon dioxide and methane are greenhouse gases (GHG) emitted from wastewater treatment that contribute to its carbon footprint. As a result of the increasing awareness of GHG emissions from wastewater treatment plants (WWTPs), new modelling, design, and operational tools have been developed to address and reduce GHG emissions at the plant-wide scale and beyond. This paper reviews the state-of-the-art and the recently developed tools used to understand and manage GHG emissions from WWTPs, and discusses open problems and research gaps. The literature review reveals that knowledge on the processes related to N2O formation, especially due to autotrophic biomass, is still incomplete. The literature review shows also that a plant-wide modelling approach that includes GHG is the best option for the understanding how to reduce the carbon footprint of WWTPs. Indeed, several studies have confirmed that a wide vision of the WWPTs has to be considered in order to make them more sustainable as possible. Mechanistic dynamic models were demonstrated as the most comprehensive and reliable tools for GHG assessment. Very few plant-wide GHG modelling studies have been applied to real WWTPs due to the huge difficulties related to data availability and the model complexity. For further improvement in GHG plant-wide modelling and to favour its use at large real scale, knowledge of the mechanisms involved in GHG formation and release, and data acquisition must be enhanced.

  12. USE OF PHASE CHANGE MATERIAL (PCM FOR FROST PREVENTION IN A MODEL GREENHOUSE

    Directory of Open Access Journals (Sweden)

    Ahmet KÜRKLÜ

    1997-02-01

    Full Text Available In this study, the possibility of using phase change materials to prevent occurrance of frost in greenhouses during winter was investigated. The melting and freezing temperatures of the PCM were about 8 oC and 4 oC, respectively.The air temperature difference between the PCM and the control greenhouses was about 2oC on average during the day and night time, PCM greenhouse having the higher temperature at night and lower temperature during the day. Frost was prevented on 7 out of 9 occasions, though the temperature difference between the greenhouses was small for some of these days. Solar fraction stored by the PCM store was about 30 %.

  13. 基于温度积分算法的温室环境控制方法%Control method for greenhouse climate based on temperature integration

    Institute of Scientific and Technical Information of China (English)

    袁洪波; 李莉; 王俊衡; N.A.Sigrimis

    2015-01-01

    温室环境控制领域所研究的大多数智能控制算法复杂程度较高,不适宜实际生产应用,生产型温室大多采用设置静态工作点模式进行简单的环境控制,这种模式无法根据环境变化进行自动调整,浪费了大量的能量。针对这一问题,提出了基于温度积分算法的温室环境控制方法,根作物种类和生长阶段确定期望平均温度值,将全天24 h均分为长度更短的若干时间片,然后利用温度积分原理对每一时间片的温度调节点进行计算,根据得到的温度调节点结合当前实际温度进行环境控制。仿真试验表明,在保持温室内实际平均温度相同的情况下,利用温度积分算法对温室进行环境调节所消耗的能量为静态工作点的模式的64.43%。该方法计算量相对较小,适用于普通的温室环境控制器,能够简单有效地实现节能控制。%In recent years, horticulture industry has been rapidly developed in China. The total area of cultivation is about 3.79 million hm2 by the end of 2012, but the climate control methods in actual greenhouse production are still relatively simple. Although many of the advanced intelligent control algorithms have been studied, however, there are two problems of these intelligent algorithms: the first one is the intelligent algorithms depend on the model of the greenhouse at the time of the operation. The control effect is better, only if the greenhouse model is accurate, but the greenhouse is a multivariable complex system with high coupling, so it is difficult to obtain accurate models. In addition, there are many different types of greenhouse in China, and each greenhouse structure may not be exactly the same, so it is inconsistent with the theoretical model. The second problem of intelligent algorithms is a large number of calculations are performed; the requirement is high for greenhouse controller’s processing capability and computing

  14. Evapotranspiration Modeling by Linear, Nonlinear Regression and Artificial Neural Network in Greenhouse (Case study Reference Crop, Cucumber and Tomato

    Directory of Open Access Journals (Sweden)

    vahid Rezaverdinejad

    2017-01-01

    Full Text Available Introduction: Greenhouse cultivation is a steadily developing agricultural sector throughout the world. In addition, it is known that water is a major issue almost all part of the world especially for countries which have insufficient water source. With this great expansion of greenhouse cultivation, the need of appropriate irrigation management has a great importance. Accurate determination of irrigation scheduling (irrigation timing and frequency is one of the main factors in achieving high yields and avoiding loss of quality in greenhouse tomato and cucumber. To do this, it is fundamental to know the crop water requirements or real evapotranspiration. Accurate estimation on crop water requirement is needed to avoid the excess or deficit water application, with consequent impacts on nutrient availability for plants. This can be done by using appropriate method to determine the crop evapotranspiration (ETc. In greenhouse cultivation, crop transpiration is the most important energy dissipation mechanisms that influence ETc rate. There are a large number of literatures on methods to estimate ETc in greenhouses. ETc can be measured or estimated by direct or indirect methods. The most common direct method estimates ETc from measurements with weighing lysimeters. Thisalsoincludes the evaporation measuring equipment, class A pan, Piche atmometer and modified atmometer. Indirect method includes the measurement of net radiation, temperature, relative humidity, and air vapour pressure deficit. A large number of models have been developed from these measurements to estimate ETc. Due to the fast development of under greenhouse cultivation all around the world, the needs of information on how it affects ETc in greenhouses has to be known and summarized. The existing models for ETc calculation have to be studied to know whether it is reliable for greenhouse climate (hereafter, microclimate or not. Regression and artificial neural network models are two

  15. Surplus thermal energy model of greenhouses and coefficient analysis for effective utilization

    Directory of Open Access Journals (Sweden)

    Seung-Hwan Yang

    2016-03-01

    Full Text Available If a greenhouse in the temperate and subtropical regions is maintained in a closed condition, the indoor temperature commonly exceeds that required for optimal plant growth, even in the cold season. This study considered this excess energy as surplus thermal energy (STE, which can be recovered, stored and used when heating is necessary. To use the STE economically and effectively, the amount of STE must be estimated before designing a utilization system. Therefore, this study proposed an STE model using energy balance equations for the three steps of the STE generation process. The coefficients in the model were determined by the results of previous research and experiments using the test greenhouse. The proposed STE model produced monthly errors of 17.9%, 10.4% and 7.4% for December, January and February, respectively. Furthermore, the effects of the coefficients on the model accuracy were revealed by the estimation error assessment and linear regression analysis through fixing dynamic coefficients. A sensitivity analysis of the model coefficients indicated that the coefficients have to be determined carefully. This study also provides effective ways to increase the amount of STE.

  16. Surplus thermal energy model of greenhouses and coefficient analysis for effective utilization

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.H.; Son, J.E.; Lee, S.D.; Cho, S.I.; Ashtiani-Araghi, A.; Rhee, J.Y.

    2016-11-01

    If a greenhouse in the temperate and subtropical regions is maintained in a closed condition, the indoor temperature commonly exceeds that required for optimal plant growth, even in the cold season. This study considered this excess energy as surplus thermal energy (STE), which can be recovered, stored and used when heating is necessary. To use the STE economically and effectively, the amount of STE must be estimated before designing a utilization system. Therefore, this study proposed an STE model using energy balance equations for the three steps of the STE generation process. The coefficients in the model were determined by the results of previous research and experiments using the test greenhouse. The proposed STE model produced monthly errors of 17.9%, 10.4% and 7.4% for December, January and February, respectively. Furthermore, the effects of the coefficients on the model accuracy were revealed by the estimation error assessment and linear regression analysis through fixing dynamic coefficients. A sensitivity analysis of the model coefficients indicated that the coefficients have to be determined carefully. This study also provides effective ways to increase the amount of STE. (Author)

  17. Exploiting the igloo principle and greenhouse effect to regulate humidity and temperature

    Directory of Open Access Journals (Sweden)

    Prabhu Karthick

    2006-01-01

    Full Text Available Background: Toxic epidermal necrolysis can be fatal and nursing care with careful monitoring of temperature and humidity can improve survival rate. We adapted the greenhouse and igloo principle using a common hood to monitor the temperature and humidity. Methods: A small heater with a regulator was placed in a mini hood and temperature was recorded inside the uncovered hood and hood covered with green cloth and aluminium foil separately. The regular hood was placed over a volunteer and the temperature was measured inside the open hood and hood covered with green cloth and aluminium foil separately. The relative humidity was also monitored using Zeal mercury dry - wet bulb hygrometer. Results: Temperature increase was most marked in the foil-covered hood followed by cloth-covered hood, both with the heater and the volunteer. Similarly, in the volunteer study, the humidity was best maintained inside the aluminium foil-covered hood. Conclusion: We recommend the use of regular hood with suitable cover to monitor the humidity and temperature of patients with toxic epidermal necrolysis.

  18. [China's rice field greenhouse gas emission under climate change based on DNDC model simulation].

    Science.gov (United States)

    Tian, Zhan; Niu, Yi-long; Sun, Lai-xiang; Li, Chang-sheng; Liu, Chun-jiang; Fan, Dong-li

    2015-03-01

    In contrast to a large body of literature assessing the impact of agriculture greenhouse gas (GHG) emissions on climate change, there is a lack of research examining the impact of climate change on agricultural GHG emissions. This study employed the DNDC v9.5, a state-of-art biogeochemical model, to simulate greenhouse gas emissions in China' s rice-growing fields during 1971-2010. The results showed that owing to temperature rising (on average 0.49 °C higher in the second 20 years than in the first 20 year) and precipitation increase (11 mm more in the second 20 years than in the first 20 years) during the rice growing season, CH4 and N2O emissions in paddy field increased by 0.25 kg C . hm-2 and 0.25 kg N . hm-2, respectively. The rising temperature accelerated CH4 emission and N2O emission increased with precipitation. These results indicated that climate change exerted impact on the mechanism of GHG emissions in paddy field.

  19. Greenhouse Gas Source Attribution: Measurements Modeling and Uncertainty Quantification

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhen [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Safta, Cosmin [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sargsyan, Khachik [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Najm, Habib N. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); van Bloemen Waanders, Bart Gustaaf [Sandia National Lab. (SNL-CA), Livermore, CA (United States); LaFranchi, Brian W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Ivey, Mark D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Schrader, Paul E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Michelsen, Hope A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bambha, Ray P. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2014-09-01

    In this project we have developed atmospheric measurement capabilities and a suite of atmospheric modeling and analysis tools that are well suited for verifying emissions of green- house gases (GHGs) on an urban-through-regional scale. We have for the first time applied the Community Multiscale Air Quality (CMAQ) model to simulate atmospheric CO2 . This will allow for the examination of regional-scale transport and distribution of CO2 along with air pollutants traditionally studied using CMAQ at relatively high spatial and temporal resolution with the goal of leveraging emissions verification efforts for both air quality and climate. We have developed a bias-enhanced Bayesian inference approach that can remedy the well-known problem of transport model errors in atmospheric CO2 inversions. We have tested the approach using data and model outputs from the TransCom3 global CO2 inversion comparison project. We have also performed two prototyping studies on inversion approaches in the generalized convection-diffusion context. One of these studies employed Polynomial Chaos Expansion to accelerate the evaluation of a regional transport model and enable efficient Markov Chain Monte Carlo sampling of the posterior for Bayesian inference. The other approach uses de- terministic inversion of a convection-diffusion-reaction system in the presence of uncertainty. These approaches should, in principle, be applicable to realistic atmospheric problems with moderate adaptation. We outline a regional greenhouse gas source inference system that integrates (1) two ap- proaches of atmospheric dispersion simulation and (2) a class of Bayesian inference and un- certainty quantification algorithms. We use two different and complementary approaches to simulate atmospheric dispersion. Specifically, we use a Eulerian chemical transport model CMAQ and a Lagrangian Particle Dispersion Model - FLEXPART-WRF. These two models share the same WRF

  20. Historical greenhouse gas concentrations for climate modelling (CMIP6)

    Science.gov (United States)

    Meinshausen, Malte; Vogel, Elisabeth; Nauels, Alexander; Lorbacher, Katja; Meinshausen, Nicolai; Etheridge, David M.; Fraser, Paul J.; Montzka, Stephen A.; Rayner, Peter J.; Trudinger, Cathy M.; Krummel, Paul B.; Beyerle, Urs; Canadell, Josep G.; Daniel, John S.; Enting, Ian G.; Law, Rachel M.; Lunder, Chris R.; O'Doherty, Simon; Prinn, Ron G.; Reimann, Stefan; Rubino, Mauro; Velders, Guus J. M.; Vollmer, Martin K.; Wang, Ray H. J.; Weiss, Ray

    2017-05-01

    Atmospheric greenhouse gas (GHG) concentrations are at unprecedented, record-high levels compared to the last 800 000 years. Those elevated GHG concentrations warm the planet and - partially offset by net cooling effects by aerosols - are largely responsible for the observed warming over the past 150 years. An accurate representation of GHG concentrations is hence important to understand and model recent climate change. So far, community efforts to create composite datasets of GHG concentrations with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since the 1980s. Here, we provide consolidated datasets of historical atmospheric concentrations (mole fractions) of 43 GHGs to be used in the Climate Model Intercomparison Project - Phase 6 (CMIP6) experiments. The presented datasets are based on AGAGE and NOAA networks, firn and ice core data, and archived air data, and a large set of published studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved and include seasonality. We focus on the period 1850-2014 for historical CMIP6 runs, but data are also provided for the last 2000 years. We provide consolidated datasets in various spatiotemporal resolutions for carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as 40 other GHGs, namely 17 ozone-depleting substances, 11 hydrofluorocarbons (HFCs), 9 perfluorocarbons (PFCs), sulfur hexafluoride (SF6), nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2). In addition, we provide three equivalence species that aggregate concentrations of GHGs other than CO2, CH4 and N2O, weighted by their radiative forcing efficiencies. For the year 1850, which is used for pre-industrial control runs, we estimate annual global-mean surface concentrations of CO2 at 284.3 ppm, CH4 at 808.2 ppb and N2O at 273.0 ppb. The data are available at https://esgf-node.llnl.gov/search/input4mips/ and http

  1. Cenozoic mean greenhouse gases and temperature changes with reference to the Anthropocene.

    Science.gov (United States)

    Glikson, Andrew

    2016-12-01

    Cenozoic greenhouse gases (GHG) variations and warming periods underscore the extreme rates of current climate change, with major implications for the adaptability and survivability of terrestrial and marine habitats. Current rise rate of greenhouse gases, reaching 3.3 ppm CO2 per year during March 2015-2016, is the fastest recorded since the Paleocene-Eocene Thermal Event (PETM) when carbon release to the atmosphere was about an order of magnitude less than at present. The ice core evidence of concentration of (GHG) and temperatures in the atmosphere/ocean/cryosphere system over the last 740 kyr suggests that the rate of rise in GHG over the last ~260 years, CO2 rates rising from 0.94 ppm yr(-1) in 1959 (315.97 ppm) to 1.62 ppm yr(-1) in 2000 (369.52 ppm) to 3.05 ppm yr(-1) in 2015 (400.83 ppm), constitutes a unique spike in the history of the atmosphere. The reliance of pre-740 kyr paleoclimate estimates on multiple proxies, including benthic and plankton fossils, fossil plants, residual organic matter, major and trace elements in fossils, sediments and soils, place limits on the resolution of pre-upper Pleistocene paleoclimate estimates, rendering it likely recorded mean Cenozoic paleoclimate trends may conceal abrupt short-term climate fluctuations. However, as exemplified by the Paleocene-Eocene thermal maximum (PETM) and earlier GHG and temperature spikes associated with major volcanic and asteroid impact events, the long-term residence time of CO2 in the atmosphere extends the signatures of abrupt warming events to within detection limits of multiple paleoproxies. The mean post-1750 temperature rise rate (approximately ~0.0034 °C per yr, or ~0.008 °C per yr where temperature is not masked by sulfur aerosols) exceeds those of the PETM (approximately ~0.0008-0.0015 °C per yr) by an order of magnitude and mean glacial termination warming rates (last glacial termination [LGT] ~ 0.00039; Eemian ~0.0004 °C per yr) by near to an order of magnitude

  2. Optimization Model for Reducing Emissions of Greenhouse Gases from Automobiles (OMEGA)

    Science.gov (United States)

    The EPA Vehicle Greenhouse Gas (VGHG) model is used to apply various technologies to a defined set of vehicles in order to meet a specified GHG emission target, and to then calculate the costs and benefits of doing so.

  3. Models of Students' Thinking Concerning the Greenhouse Effect and Teaching Implications.

    Science.gov (United States)

    Koulaidis, Vasilis; Christidou, Vasilia

    1999-01-01

    Primary school students (n=40) ages 11 and 12 years were interviewed concerning their conceptions of the greenhouse effect. Analysis of the data led to the formation of seven distinct models of thinking regarding this phenomenon. (Author/CCM)

  4. Altitude dependence of atmospheric temperature trends: Climate models versus observation

    CERN Document Server

    Douglass, D H; Singer, F

    2004-01-01

    As a consequence of greenhouse forcing, all state of the art general circulation models predict a positive temperature trend that is greater for the troposphere than the surface. This predicted positive trend increases in value with altitude until it reaches a maximum ratio with respect to the surface of as much as 1.5 to 2.0 at about 200 to 400 hPa. However, the temperature trends from several independent observational data sets show decreasing as well as mostly negative values. This disparity indicates that the three models examined here fail to account for the effects of greenhouse forcings.

  5. Elevating CO2 in commercial greenhouses can reduce carbon use and production cost in cool temperatures

    Science.gov (United States)

    When greenhouses are heated in the cooler months, growers attempt to minimize gaps to reduce air infiltration. Greenhouses that are well sealed can result in CO2 drawdown to the detriment of plant growth. Growers can opt to counteract the low CO2 by supplementing with CO2. However, it is unknown how...

  6. MAMM (Methane and other greenhouse gases in the Arctic - Measurements, process studies and Modelling) progress report

    Science.gov (United States)

    Nisbet, E. G.; Pyle, J. A.

    2012-12-01

    MAMM consortium (led by JA Pyle, Univ. Cambridge, with partners from Univ. East Anglia; Univ. Manchester; Royal Holloway, Univ. of London; NERC Centre for Ecology and Hydrology). The UK MAMM project (Methane and other greenhouse gases in the Arctic - Measurements, process studies and Modelling) is designed to improve quantitative knowledge of Arctic methane and other greenhouse gases from various sources (e.g. wetlands, natural gas, clathrates), to determine magnitudes and spatial distributions, and to develop process understanding (e.g. dependence of fluxes on temperature). In Arctic Finland, Sweden, Norway and Spitsbergen, intensive low-level aircraft campaigns (flights in spring, summer, autumn 2012 and 2013, with the UK FAAM BAe146 aircraft) are designed to measure concentrations of CH4 and other gases across the Arctic by time and location, with in situ sampling for δ13CCH4 at selected sites on land (Zeppelin, Pallas, Alert) and Keeling-plot diel determination of wetland source signatures. High altitude flights sampled stratosphere-troposphere exchange in the Arctic to assess the impact of the polar vortex on methane isotope budgets. Methane column profiles are measured by combining ground based eddy covariance and chamber measurements with aircraft measurements, using a landscape-scale box model approach and flying up and downwind of source regions. Airborne remote sensing is being used to retrieve CH4 columns for comparison with in-situ profiles and testing of hyperspectral retrieval methods from satellite platforms. Longer-term time series measurements are also being established in Kjølnes, northern Norway, for a range of greenhouse and related species via continuous or flask/bag sampling. Modelling studies are in progress to assess the overall Arctic influence on the global methane budget, including detailed back-trajectory analysis of the measurements, especially the isotopic data, to identify sources of methane by location, type (e.g. gasfield, wetland

  7. Observational determination of the greenhouse effect

    Science.gov (United States)

    Raval, A.; Ramanathan, V.

    1989-01-01

    Satellite measurements are used to quantify the atmospheric greenhouse effect, defined here as the infrared radiation energy trapped by atmospheric gases and clouds. The greenhouse effect is found to increase significantly with sea surface temperature. The rate of increase gives compelling evidence for the positive feedback between surface temperature, water vapor and the greenhouse effect; the magnitude of the feedback is consistent with that predicted by climate models. This study demonstrates an effective method for directly monitoring, from space, future changes in the greenhouse effect.

  8. Impacts of temperature and nitrogen addition on greenhouse gas fluxes from turfgrass and coastal salt marshes

    Science.gov (United States)

    Glennon, K.; Moseman-Valtierra, S.; Brown, R.; Quinn, R. K.; Brannon, E.; Amador, J.; Craver, V.

    2016-12-01

    Climate change and nitrogen (N) loading from wastewater and fertilization are both increasingly significant anthropogenic drivers of ecosystem change. Among the ecosystems affected by these drivers are coastal salt marshes, although turf grasses are often direct recipients of N inputs prior to their discharge to the coast. To estimate changes in greenhouse gas emissions from coastal marsh grasses and turfgrasses, we created a mesocosm experiment using a common turfgrass (Schedonorus arundinaceus) and a dominant native coastal cordgrass (Spartina alterniflora) in growth chambers kept under current and projected future temperatures with or without added N inputs. For N fertilization, we used recovered biosolids from wastewater sludge. We measured fluxes of N2O, CO2, and CH4 in the mesocosms through a growing season, the summer of 2016. Above and belowground biomass will be compared between experimental treatments and tested as a potential proxy for CO2 fluxes along with soil properties, including salinity, moisture, and DIN. Preliminary results indicate that there were few significant fluxes of N2O from the mesocosm plots. Both the highest N2O and CO2 emissions (9.6 umol m-2 h-1 and 15.1 m-2 s-1 respectively) were measured from turfgrass mesocosms. The highest CH4 emissions (61.9 umol m-2 h-1) were measured from cordgrass mesocosms. This data will be used to determine if fertilization using recovered biosolids is a sustainable method of fertilizer application.

  9. Air Surface Temperature Correlation with Greenhouse Gases by Using Airs Data Over Peninsular Malaysia

    Science.gov (United States)

    Rajab, Jasim Mohammed; MatJafri, M. Z.; Lim, H. S.

    2014-08-01

    The main objective of this study is to develop algorithms for calculating the air surface temperature (AST). This study also aims to analyze and investigate the effects of greenhouse gases (GHGs) on the AST value in Peninsular Malaysia. Multiple linear regression is used to achieve the objectives of the study. Peninsular Malaysia has been selected as the research area because it is among the regions of tropical Southeast Asia with the greatest humidity, pockets of heavy pollution, rapid economic growth, and industrialization. The predicted AST was highly correlated ( R = 0.783) with GHGs for the 6-year data (2003-2008). Comparisons of five stations in 2009 showed close agreement between the predicted AST and the observed AST from AIRS, especially in the wet season (within 1.3 K). The in situ data ranged from 1 to 2 K. Validation results showed that AST ( R = 0.776-0.878) has values nearly the same as the observed AST from AIRS. We found that O3 during the wet season was indicated by a strongly positive beta coefficient (0.264-0.992) with AST. The CO2 yields a reasonable relationship with temperature with low to moderate beta coefficient (-0.065 to 0.238). The O3, CO2, and environmental variables experienced different seasonal fluctuations that depend on weather conditions and topography. The concentration of gases and pollution were the highest over industrial zones and overcrowded cities, and the dry season was more polluted compared with the wet season. These results indicate the advantage of using the satellite AIRS data and a correlation analysis to investigate the effect of atmospheric GHGs on AST over Peninsular Malaysia. An algorithm that is capable of retrieving Peninsular Malaysian AST in all weather conditions with total uncertainties ranging from 1 to 2 K was developed.

  10. Estimating Policy-Driven Greenhouse Gas Emissions Trajectories in California: The California Greenhouse Gas Inventory Spreadsheet (GHGIS) Model

    Energy Technology Data Exchange (ETDEWEB)

    Greenblatt, Jeffery B.

    2013-10-10

    A California Greenhouse Gas Inventory Spreadsheet (GHGIS) model was developed to explore the impact of combinations of state policies on state greenhouse gas (GHG) and regional criteria pollutant emissions. The model included representations of all GHG- emitting sectors of the California economy (including those outside the energy sector, such as high global warming potential gases, waste treatment, agriculture and forestry) in varying degrees of detail, and was carefully calibrated using available data and projections from multiple state agencies and other sources. Starting from basic drivers such as population, numbers of households, gross state product, numbers of vehicles, etc., the model calculated energy demands by type (various types of liquid and gaseous hydrocarbon fuels, electricity and hydrogen), and finally calculated emissions of GHGs and three criteria pollutants: reactive organic gases (ROG), nitrogen oxides (NOx), and fine (2.5 ?m) particulate matter (PM2.5). Calculations were generally statewide, but in some sectors, criteria pollutants were also calculated for two regional air basins: the South Coast Air Basin (SCAB) and the San Joaquin Valley (SJV). Three scenarios were developed that attempt to model: (1) all committed policies, (2) additional, uncommitted policy targets and (3) potential technology and market futures. Each scenario received extensive input from state energy planning agencies, in particular the California Air Resources Board. Results indicate that all three scenarios are able to meet the 2020 statewide GHG targets, and by 2030, statewide GHG emissions range from between 208 and 396 MtCO2/yr. However, none of the scenarios are able to meet the 2050 GHG target of 85 MtCO2/yr, with emissions ranging from 188 to 444 MtCO2/yr, so additional policies will need to be developed for California to meet this stringent future target. A full sensitivity study of major scenario assumptions was also performed. In terms of criteria pollutants

  11. Modeling of Energy Demand in the Greenhouse Using PSO-GA Hybrid Algorithms

    Directory of Open Access Journals (Sweden)

    Jiaoliao Chen

    2015-01-01

    Full Text Available Modeling of energy demand in agricultural greenhouse is very important to maintain optimum inside environment for plant growth and energy consumption decreasing. This paper deals with the identification parameters for physical model of energy demand in the greenhouse using hybrid particle swarm optimization and genetic algorithms technique (HPSO-GA. HPSO-GA is developed to estimate the indistinct internal parameters of greenhouse energy model, which is built based on thermal balance. Experiments were conducted to measure environment and energy parameters in a cooling greenhouse with surface water source heat pump system, which is located in mid-east China. System identification experiments identify model parameters using HPSO-GA such as inertias and heat transfer constants. The performance of HPSO-GA on the parameter estimation is better than GA and PSO. This algorithm can improve the classification accuracy while speeding up the convergence process and can avoid premature convergence. System identification results prove that HPSO-GA is reliable in solving parameter estimation problems for modeling the energy demand in the greenhouse.

  12. Understanding the Asian summer monsoon response to greenhouse warming: the relative roles of direct radiative forcing and sea surface temperature change

    Science.gov (United States)

    Li, Xiaoqiong; Ting, Mingfang

    2016-12-01

    Future hydroclimate projections from state-of-the-art climate models show large uncertainty and model spread, particularly in the tropics and over the monsoon regions. The precipitation and circulation responses to rising greenhouse gases involve a fast component associated with direct radiative forcing and a slow component associated with sea surface temperature (SST) warming; the relative importance of the two may contribute to model discrepancies. In this study, regional hydroclimate responses to greenhouse warming are assessed using output from coupled general circulation models in the Coupled Model Intercomparison Project-Phase 5 (CMIP5) and idealized atmospheric general circulation model experiments from the Atmosphere Model Intercomparison Project. The thermodynamic and dynamic mechanisms causing the rainfall changes are examined using moisture budget analysis. Results show that direct radiative forcing and SST change exert significantly different responses both over land and ocean. For most part of the Asian monsoon region, the summertime rainfall changes are dominated by the direct CO2 radiative effect through enhanced monsoon circulation. The response to SST warming shows a larger model spread compared to direct radiative forcing, possibly due to the cancellation between the thermodynamical and dynamical components. While the thermodynamical response of the Asian monsoon is robust across the models, there is a lack of consensus for the dynamical response among the models and weak multi-model mean responses in the CMIP5 ensemble, which may be related to the multiple physical processes evolving on different time scales.

  13. Comparing solubility algorithms of greenhouse gases in Earth-System modelling

    Directory of Open Access Journals (Sweden)

    V. M. N. C. S. Vieira

    2015-09-01

    Full Text Available Accurate solubility estimates are fundamental for (i Earth-System models forecasting the climate change taking into consideration the atmosphere–ocean balances and trades of greenhouse gases, and (ii using field data to calibrate and validate the algorithms simulating those trades. We found important differences between the formulation generally accepted and a recently proposed alternative relying on a different chemistry background. First, we tested with field data from the Baltic Sea, which also enabled finding differences between using water temperatures measured at 0.5 or 4 m depths. Then, we used data simulated by atmospheric (Meteodata application of WRF and oceanographic (WW3-NEMO models of the European Coastal Ocean and Mediterranean to compare the use of the two solubility algorithms in Earth-System modelling. The mismatches between both formulations lead to a difference of millions of tons of CO2, and hundreds of tons of CH4 and N2O, dissolved in the first meter below the sea surface of the whole modelled region.

  14. Advances and bottlenecks in modelling the greenhouse climate: summary of a group discussion

    NARCIS (Netherlands)

    Seginer, I.; Bakker, J.C.

    1998-01-01

    This report is a summary of a group discussion at the symposium 'Models in protected cultivation' held in Wageningen, August 1997. The discussion focused on the reasons for the relatively limited acceptance and application of greenhouse climate models, especially in commercial practice. The discussi

  15. Modelling of water potential and water uptake rate of tomato plants in the greenhouse: preliminary results.

    NARCIS (Netherlands)

    Bruggink, G.T.; Schouwink, H.E.; Gieling, Th.H.

    1988-01-01

    A dynamic model is presented which predicts water potential and water uptake rate of greenhouse tomato plants using transpiration rate as input. The model assumes that water uptake is the resultant of water potential and hydraulic resistance, and that water potential is linearly related to water con

  16. IMAGE: An Integrated Model for the Assessment of the Greenhouse Effect

    NARCIS (Netherlands)

    Rotmans J; Boois H de; Swart RJ

    1989-01-01

    In dit rapport wordt beschreven hoe het RIVM-simulatiemodel IMAGE (an Integrated Model for the Assessment of the Greenhouse Effect) is opgebouwd. Het model beoogt een geintegreerd overzicht te geven van de broeikasproblematiek alsmede inzicht te verschaffen in de wezenlijke drijfveren van het

  17. Modeling of municipal greenhouse gas emissions. Calculation of greenhouse gas emissions and the reduction possibilities of Dutch municipalities

    NARCIS (Netherlands)

    Vries de, Willem

    2011-01-01

    Summary Municipalities represent an active governmental layer in the Netherlands. They often have ambitions to reduce greenhouse gas emissions. In this way the municipalities take responsibility to reduce the threat of global warming. To implement effect

  18. User-Friendly Predictive Modeling of Greenhouse Gas (GHG) Fluxes and Carbon Storage in Tidal Wetlands

    Science.gov (United States)

    Ishtiaq, K. S.; Abdul-Aziz, O. I.

    2015-12-01

    We developed user-friendly empirical models to predict instantaneous fluxes of CO2 and CH4 from coastal wetlands based on a small set of dominant hydro-climatic and environmental drivers (e.g., photosynthetically active radiation, soil temperature, water depth, and soil salinity). The dominant predictor variables were systematically identified by applying a robust data-analytics framework on a wide range of possible environmental variables driving wetland greenhouse gas (GHG) fluxes. The method comprised of a multi-layered data-analytics framework, including Pearson correlation analysis, explanatory principal component and factor analyses, and partial least squares regression modeling. The identified dominant predictors were finally utilized to develop power-law based non-linear regression models to predict CO2 and CH4 fluxes under different climatic, land use (nitrogen gradient), tidal hydrology and salinity conditions. Four different tidal wetlands of Waquoit Bay, MA were considered as the case study sites to identify the dominant drivers and evaluate model performance. The study sites were dominated by native Spartina Alterniflora and characterized by frequent flooding and high saline conditions. The model estimated the potential net ecosystem carbon balance (NECB) both in gC/m2 and metric tonC/hectare by up-scaling the instantaneous predicted fluxes to the growing season and accounting for the lateral C flux exchanges between the wetlands and estuary. The entire model was presented in a single Excel spreadsheet as a user-friendly ecological engineering tool. The model can aid the development of appropriate GHG offset protocols for setting monitoring plans for tidal wetland restoration and maintenance projects. The model can also be used to estimate wetland GHG fluxes and potential carbon storage under various IPCC climate change and sea level rise scenarios; facilitating an appropriate management of carbon stocks in tidal wetlands and their incorporation into a

  19. 半地下立窗型日光温室采光效率模型及温光性能优化%Lighting Efficiency Model and Optimization of Temperature and Light Performance in Semi-underground Vertical Window Type Solar Greenhouse

    Institute of Scientific and Technical Information of China (English)

    王梅; 高志奎; 王俊玲

    2013-01-01

      以日光温室空间地面作物受光点为核心,根据半地下立窗型日光温室的结构特点,建立日光温室采光性能实用型优化的数学模型,并以定州地区(北纬38°31')为例,根据温室平均采光效率ηs、采光屋面保温效率τ和有效升温效率υ、温室采光面下土地使用效率φ4个评价参数,结合模型模拟运算结果进行了实用型优化。结果表明,半地下立窗型日光温室前屋面的曲线类型可以在立窗+圆弧面、立窗+椭圆面和立窗+抛物线面3种采光面中任选其一;日光温室内跨和半地下深度对ηs和τ的影响较大,半地下深度超过30 cm时,τ呈线性锐减趋势;脊高增加,υ呈线性锐减趋势;脊高和内跨增加,则φ呈明显线性增加趋势;立窗高度增加,则φ呈明显线性增加且最后呈饱和趋势;半地下深度超过75 cm时,φ呈线性锐减趋势。据此,半地下立窗型日光温室的优型结构参数选定为:脊高以340~360 cm为宜、日光温室内跨以900~1000 cm为宜、立窗高度以75~115 cm为宜、半地下深度以30~45 cm为宜。%  Taking light acceptance spots of crops in solar greenhouse as the core, a practical optimized mathematic model of lighting performance was established according to the structural characteristics of semi-underground vertical window type solar greenhouse. Taking Dingzhou region (north latitude 38°31') for example, the results of practical optimization combined with model simulation showed that, we could chose one of three lighting roof curve types for semi-underground vertical window type solar greenhouse optionally, including vertical window+arc surface, vertical window+elliptical surface and vertical window+parabolic surface, according to four evaluation parameters, average lighting efficiency in greenhouse (ηs), insulation efficiency of lighting roof (τ), effective temperature-rising efficiency (υ) and soil

  20. Fan and Pad Evaporative Cooling System for Greenhouses: Evaluation of a Numerical and Analytical Model

    NARCIS (Netherlands)

    Sapounas, A.; Nikita-Martzopoulou, Ch.; Bartzanas, T.; Kittas, C.

    2008-01-01

    An experimental greenhouse equipped with fan and pad evaporative cooling is analysed using two different models. The first one consists of a numerical simulation approach applying a commercial CFD code. The main aspects of evaporative cooling systems, in terms of heat and mass transfer and both the

  1. Factor Analysis of Drawings: Application to College Student Models of the Greenhouse Effect

    Science.gov (United States)

    Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel

    2015-01-01

    Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance,…

  2. Modelling the effect of supplementary lighting on production and light utilisation efficiency of greenhouse crops.

    NARCIS (Netherlands)

    Koning, de J.C.M.

    1997-01-01

    The effect of supplementary lighting (SL) on dry matter production of greenhouse crops is predictable with ALSIM, a new crop growth model based on SUCROS87. The light utilization efficiency (LUE), defined as daily dry matter production divided by the daily photosynthetic photon flux is a parameter f

  3. Modeling the infrastructure dynamics of China -- Water, agriculture, energy, and greenhouse gases

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, S.H.; Drennen, T.E.; Engi, D.; Harris, D.L.; Jeppesen, D.M.; Thomas, R.P.

    1998-08-01

    A comprehensive critical infrastructure analysis of the People`s Republic of China was performed to address questions about China`s ability to meet its long-term grain requirements and energy needs and to estimate greenhouse gas emissions in China likely to result from increased agricultural production and energy use. Four dynamic computer simulation models of China`s infrastructures--water, agriculture, energy and greenhouse gas--were developed to simulate, respectively, the hydrologic budgetary processes, grain production and consumption, energy demand, and greenhouse gas emissions in China through 2025. The four models were integrated into a state-of-the-art comprehensive critical infrastructure model for all of China. This integrated model simulates diverse flows of commodities, such as water and greenhouse gas, between the separate models to capture the overall dynamics of the integrated system. The model was used to generate projections of China`s available water resources and expected water use for 10 river drainage regions representing 100% of China`s mean annual runoff and comprising 37 major river basins. These projections were used to develop estimates of the water surpluses and/or deficits in the three end-use sectors--urban, industrial, and agricultural--through the year 2025. Projections of the all-China demand for the three major grains (corn, wheat, and rice), meat, and other (other grains and fruits and vegetables) were also generated. Each geographic region`s share of the all-China grain demand (allocated on the basis of each region`s share of historic grain production) was calculated in order to assess the land and water resources in each region required to meet that demand. Growth in energy use in six historically significant sectors and growth in greenhouse gas loading were projected for all of China.

  4. Using flowering and heat-loss models for improving greenhouse energy-use efficiency in annual bedding plant production

    Science.gov (United States)

    In temperate climates, annual bedding plants are typically produced in heated greenhouses from late winter through early summer. Temperature, photoperiod, light intensity, and transplant date are commonly manipulated during commercial production so that plants are in flower for predetermined market ...

  5. Logistic Equation and its Application as Forecasting Model of Vegetables Production in Greenhouses in Albania

    Directory of Open Access Journals (Sweden)

    VALENTINA SHEHU

    2015-10-01

    Full Text Available Correct forecasting is of a great importance for the business and economy of the country. To comprehend the market and the economic system, mathematical models are used to describe and predict the future of situation. Agriculture is the spinal column of Albania’s economic activity and the last 20 years free market experience has given a demonstration of the high correlation between agricultural progress and the economic development. Producing greenhouse-grown vegetables can result a beneficial activity, but it is a hard and complicated investment. The greenhouse technology is one of great innovation in agriculture. Agricultures methods must be combined with technical knowledge, marketing must be planned before harvest, and every phase of process should be well-managed. In this paper it is studied and applied the logistic growth model for forecasting the production of vegetables in greenhouse. The results of this paper show that the logistic S-shaped curve is a mathematical model to characterize the progress of innovation in agriculture. Also, the logistic equation can be used to describe and predict the production of vegetables in greenhouses in Albania.

  6. Regional modelling of future African climate north of 15S including greenhouse warming and land degradation

    Energy Technology Data Exchange (ETDEWEB)

    Paeth, H. [Geographical Institute, University of Wuerzburg, Am Hubland, 97074 Wuerzburg (Germany); Thamm, H.P. [Geographical Institute, University of Bonn, Bonn (Germany)

    2007-08-15

    Previous studies have highlighted the crucial role of land degradation in tropical African climate. This effect urgently has to be taken into account when predicting future African climate under enhanced greenhouse conditions. Here, we present time slice experiments of African climate until 2025, using a high-resolution regional climate model. A supposable scenario of future land use changes, involving vegetation loss and soil degradation, is prescribed simultaneously with increasing greenhouse-gas concentrations in order to detect, where the different forcings counterbalance or reinforce each other. This proceeding allows us to define the regions of highest vulnerability with respect to future freshwater availability and food security in tropical and subtropical Africa and may provide a decision basis for political measures. The model simulates a considerable reduction in precipitation amount until 2025 over most of tropical Africa, amounting to partly more than 500 mm (20-40% of the annual sum), particularly in the Congo Basin and the Sahel Zone. The change is strongest in boreal summer and basically reflects the pattern of maximum vegetation cover during the seasonal cycle. The related change in the surface energy fluxes induces a substantial near-surface warming by up to 7C. According to the modified temperature gradients over tropical Africa, the summer monsoon circulation intensifies and transports more humid air masses into the southern part of West Africa. This humidifying effect is overcompensated by a remarkable decrease in surface evaporation, leading to the overall drying tendency over most of Africa. Extreme daily rainfall events become stronger in autumn but less intense in spring. Summer and autumn appear to be characterized by more severe heat waves over Subsaharan West Africa. In addition, the Tropical Easterly Jet is weakening, leading to enhanced drought conditions in the Sahel Zone. All these results suggest that the local impact of land

  7. Carbon exchange in Western Siberian watershed mires and implication for the greenhouse effect. A spatial temporal modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Borren, W.

    2007-01-19

    The vast watershed mires of Western Siberia formed a significant sink of carbon during the Holocene. Because of their large area these mires might play an important role in the carbon exchange between terrestrial ecosystems and the atmosphere. However, estimation of the Holocene and future carbon balance of whole Western Siberian mires is hampered by the lack of spatially resolved models. The main objective was to assess the carbon exchange fluxes of the mires using a 3-D dynamic approach. These exchange fluxes comprise the sequestration of carbon dioxide (CO2) by peat growth, the emission of methane (CH4) by anaerobic peat decay and the emission of CO2 by aerobic peat decay. From the detailed analysis of peat cores from different sites in the southern taiga of Western Siberia, it emerged that Holocene peat growth and carbon accumulation had different trends, caused by variations in vegetation succession. These differences were strongly influenced by the position in the landscape. Therefore, the effect of climatic change on mire development varied spatially. The indirect effects of climate change through local hydrology appeared to be more important than direct influences of changes in precipitation and temperature. Mire development is closely connected to hydrological dynamics. In the thesis a 3-D dynamic modeling approach is described that makes use of groundwater modeling. In successive timesteps peat growth and decay as well as mire type distribution were calculated, depending on hydrological conditions. The model was forced with a paleo-precipitation record to include variable climatic input. The model results show the Holocene development of a watershed mire from a few small spots to a contiguous mire landscape. As hydrology is the major limiting factor, the mire development is most sensitive to precipitation and evapotranspiration. Under unchanged conditions the mire will grow further, eventually reaching its maximum peat thickness around 11400 yr A.D. Under

  8. Effect of Temperature on Imago Life Span, Fecundity and Reproduction Rate of Greenhouse Whitefly (T. vaporariorum W.

    Directory of Open Access Journals (Sweden)

    Pantelija Perić

    2006-01-01

    Full Text Available Imago life span, fecundity and survival rate of the different developmental stages and average abundance of female offspring of greenhouse whitefly (Trialeurodes vaporariorum were studied at three constant (18, 22 and 27°C and one alternating (18/7°C temperature.Temperature highs are inversely proportionate to imago life span. Temperature increase from 18/7°C to 27°C decreased the whitefly life span 3.3-fold. Under 18°C and 22°C, whitefly laid eggs most abundantly (147 and 126, respectively, while fecundity decreased under lower and higher temperatures. Half the offspring of the investigated whitefly laboratory strain (49.5% were males, which resulted in lower values of reproduction and growth rates of the whitefly strain.Optimum development of greenhouse whitefly was achieved at 18°C, which is evident from a maximum number of eggs laid and highest average number of potential and actual female offspring (68.2 and 58.3, respectively, compared to the other investigated temperatures.The consequence of a 50.8-day long true generation time is evident from the low values of growth capacity (0.074 and intrinsic rate of increase (0.080. With temperature increasing to 22°C and 27°C, the period of whitefly oviposition showed a tendency to decrease further on. Higher temperatures reduced the total abundance of eggs laid and, consequently, the abundance of potential and actual female offspring, but increased growth rate.

  9. Effects of Light and Temperature on Uptake and Distribution of Nitrogen, Phosphorus and Potassium of Cucumber in Solar Greenhouse

    Institute of Scientific and Technical Information of China (English)

    PEI Xiao-bo; ZHANG Fu-man; WANG Liu

    2002-01-01

    The influence of light and temperature conditions inside solar greenhouse of winter-spring and autumn-winter crop in northern China on uptake and distribution of nitrogen, phosphorus and potassium of cucumber was studied. The results showed that plant root development and uptake and distribution of N, P and K benefited more from inside light and temperature changes in winter-spring crop. Root volume and root activity increased more rapidly in winter-spring than in autumn-winter. Uptake of total N, P2O5 and K2O increased with plant development in winter-spring, and declined in autumn-winter crop. Distribution of total N,P2O5 and K2O at different part of cucumber at fruit bearing stage was significantly influenced by inside light and temperature of solar greenhouse. Total N, P2O5 and K2O were mainly distributed to leaves and stems at early stage, and increasingly to fruits after fruit bearing.

  10. Influence of Sea Surface Temperature, Tropospheric Humidity and Lapse Rate on the Annual Cycle of the Clear-Sky Greenhouse Effect

    Science.gov (United States)

    Hu, H.; Liu, W.

    2000-01-01

    The implication of this work will provide modeling study a surrogate of annual cycle of the greenhouse effect. For example, the model should be able to simulate the annual cycle before it can be used for global change study.

  11. 77 FR 64051 - 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel...

    Science.gov (United States)

    2012-10-18

    ... Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy Standards... standards to improve fuel economy and reduce greenhouse gas emissions for vehicles manufactured for sale in... and address global climate change. Need for Correction As published, the final...

  12. Greenhouse gas simulations with a coupled meteorological and transport model: the predictability of CO2

    Science.gov (United States)

    Polavarapu, Saroja M.; Neish, Michael; Tanguay, Monique; Girard, Claude; de Grandpré, Jean; Semeniuk, Kirill; Gravel, Sylvie; Ren, Shuzhan; Roche, Sébastien; Chan, Douglas; Strong, Kimberly

    2016-09-01

    A new model for greenhouse gas transport has been developed based on Environment and Climate Change Canada's operational weather and environmental prediction models. When provided with realistic posterior fluxes for CO2, the CO2 simulations compare well to NOAA's CarbonTracker fields and to near-surface continuous measurements, columns from the Total Carbon Column Observing Network (TCCON) and NOAA aircraft profiles. This coupled meteorological and tracer transport model is used to study the predictability of CO2. Predictability concerns the quantification of model forecast errors and thus of transport model errors. CO2 predictions are used to compute model-data mismatches when solving flux inversion problems and the quality of such predictions is a major concern. Here, the loss of meteorological predictability due to uncertain meteorological initial conditions is shown to impact CO2 predictability. The predictability of CO2 is shorter than that of the temperature field and increases near the surface and in the lower stratosphere. When broken down into spatial scales, CO2 predictability at the very largest scales is mainly due to surface fluxes but there is also some sensitivity to the land and ocean surface forcing of meteorological fields. The predictability due to the land and ocean surface is most evident in boreal summer when biospheric uptake produces large spatial gradients in the CO2 field. This is a newly identified source of uncertainty in CO2 predictions but it is expected to be much less significant than uncertainties in fluxes. However, it serves as an upper limit for the more important source of transport error and loss of predictability, which is due to uncertain meteorological analyses. By isolating this component of transport error, it is demonstrated that CO2 can only be defined on large spatial scales due to the presence of meteorological uncertainty. Thus, for a given model, there is a spatial scale below which fluxes cannot be inferred simply

  13. Study on the idity fuzzy neural network controller based on improved genetic algorithm of intelligent temperature control system in vegetable greenhouse

    Science.gov (United States)

    Zhang, Su; Yuan, Hongbo; Zhou, Yuhong; Wang, Nan

    2009-07-01

    In order to create the environment that the suitable crop grows, direct against the characteristic of the system of the greenhouse. The aim of the research was to study the intelligent temperature control system in vegetable greenhouse. Based on computer automatic control ,a kind of intelligent temperature control system in vegetable greenhouse was designed. The design thought of systematic hardwares such as temperature collection system, temperature display, control system, heater control circuit in the heater were expounded in detail The control algorithm of the system was improved and system simulation was made by using MATLAB finally. The control algorithm of the system was improved by a new fuzzy neural network controller. The stimulation curve showed that the system had better controlling and tracking performances ,higher accuracy of controlling the temperature. And this system and host epigyny computer could constitute the secondary computer control system which was favorable for realizing the centralized management of the production.

  14. Comparison of different modeling approaches to better evaluate greenhouse gas emissions from whole wastewater treatment plants.

    Science.gov (United States)

    Corominas, Lluís; Flores-Alsina, Xavier; Snip, Laura; Vanrolleghem, Peter A

    2012-11-01

    New tools are being developed to estimate greenhouse gas (GHG) emissions from wastewater treatment plants (WWTPs). There is a trend to move from empirical factors to simple comprehensive and more complex process-based models. Thus, the main objective of this study is to demonstrate the importance of using process-based dynamic models to better evaluate GHG emissions. This is tackled by defining a virtual case study based on the whole plant Benchmark Simulation Model Platform No. 2 (BSM2) and estimating GHG emissions using two approaches: (1) a combination of simple comprehensive models based on empirical assumptions and (2) a more sophisticated approach, which describes the mechanistic production of nitrous oxide (N(2) O) in the biological reactor (ASMN) and the generation of carbon dioxide (CO(2) ) and methane (CH(4) ) from the Anaerobic Digestion Model 1 (ADM1). Models already presented in literature are used, but modifications compared to the previously published ASMN model have been made. Also model interfaces between the ASMN and the ADM1 models have been developed. The results show that the use of the different approaches leads to significant differences in the N(2) O emissions (a factor of 3) but not in the CH(4) emissions (about 4%). Estimations of GHG emissions are also compared for steady-state and dynamic simulations. Averaged values for GHG emissions obtained with steady-state and dynamic simulations are rather similar. However, when looking at the dynamics of N(2) O emissions, large variability (3-6 ton CO(2) e day(-1) ) is observed due to changes in the influent wastewater C/N ratio and temperature which would not be captured by a steady-state analysis (4.4 ton CO(2) e day(-1) ). Finally, this study also shows the effect of changing the anaerobic digestion volume on the total GHG emissions. Decreasing the anaerobic digester volume resulted in a slight reduction in CH(4) emissions (about 5%), but significantly decreased N(2) O emissions in

  15. [Effects of low temperature and weak light on the functions of photosystem in Prunus armeniaca L. leaves in solar greenhouse].

    Science.gov (United States)

    Sun, Shan; Zhang, Li-tao; Wang, Jia-Xi; Wang, Shao-Min; Gao, Hua-Jun; Gao, Hui-Yuan

    2008-03-01

    In this paper, the net photosynthetic rate (Pn), actual photochemical efficiency of PS II (PhiPSII), photochemical quenching (qp), and maximal photochemical efficiency of PS II in light (Fv'/Fm') of apricot (Prunus armeniaca) leaves in solar greenhouse were measured, and the effects of low temperature (7 degrees C) and weak light (200 micromol x m(-2) x s(-1) PFD) on the photoinhibition of PS I and PS II were investigated. The results showed that the optimal temperature for the photosynthesis of apricot leaves was around 25 degrees C, and the photosynthetic capacity was reduced greatly by the low temperature and weak light, inducing a markedly increased excitation press (1-qp) and in turn, resulting in photoinhibition. The functions of both PS I and PS II were damaged by the low temperature and weak light. Comparing with those only subjected to low temperature, the leaves subjected to both low temperature and weak light had a decreased activity of PS I, with a decrement of 28.26% within 2 h, but their maximal photochemical effeciency of PS II (Fv/Fm) had little change in the same period, suggesting that under low temperature and weak light, PS I was more suffered from photoinhibition than PS II.

  16. Optimizing illumination in the greenhouse using a 3D model of tomato and a ray tracer

    Directory of Open Access Journals (Sweden)

    Pieter Huibert Bram De Visser

    2014-02-01

    Full Text Available Reduction of energy use for assimilation lighting is one of the most urgent goals of current greenhouse horticulture in the Netherlands. In recent years numerous lighting systems have been tested in greenhouses, yet their efficiency has been very difficult to measure in practice. This simulation study evaluated a number of lighting strategies using a 3D light model for natural and artificial light in combination with a 3D model of tomato. The modeling platform GroIMP was used for the simulation study. The crop was represented by 3D virtual plants of tomato with fixed architecture. Detailed data on greenhouse architecture and lamp emission patterns of different light sources were incorporated in the model. A number of illumination strategies were modeled with the calibrated model. Results were compared to the standard configuration. Moreover, adaptation of leaf angles was incorporated for testing their effect on light use efficiency. A Farquhar photosynthesis model was used to translate the absorbed light for each leaf into a produced amount of carbohydrates. The carbohydrates produced by the crop per unit emitted light from sun or HPS lamps was the highest for horizontal leaf angles or slightly downward pointing leaves, and was less for more upward leaf orientations. The simulated leaf angles did not affect light absorption from inter-lighting LED modules, but the scenario with LEDs shining slightly upward (20° increased light absorption and light use efficiency relative to default horizontal beaming LEDs. Furthermore, the model showed that leaf orientation more perpendicular to the string of LEDs increased LED light interception.The combination of a ray tracer and a 3D crop model could compute optimal lighting of leaves by quantification of light fluxes and illustration by rendered lighting patterns. Results indicate that illumination efficiency increases when the lamp light is directed at most to leaves that have a high photosynthetic

  17. Response of tomato crop growth and development to a vertical temperature gradient in a semi-closed greenhouse

    NARCIS (Netherlands)

    Qian, T.; Dieleman, J.A.; Elings, A.; Gelder, de A.; Marcelis, L.F.M.

    2015-01-01

    Semi-closed greenhouses have been developed over the last decade to conserve energy. Energy consumption is reduced by collecting the excess solar energy in Summer, storing it in aquifers and re-using it in Winter to heat the greenhouse. Cooling systems placed in the lower part of the greenhouse, can

  18. Estimating greenhouse gas emissions of European cities--modeling emissions with only one spatial and one socioeconomic variable.

    Science.gov (United States)

    Baur, Albert H; Lauf, Steffen; Förster, Michael; Kleinschmit, Birgit

    2015-07-01

    Substantive and concerted action is needed to mitigate climate change. However, international negotiations struggle to adopt ambitious legislation and to anticipate more climate-friendly developments. Thus, stronger actions are needed from other players. Cities, being greenhouse gas emission centers, play a key role in promoting the climate change mitigation movement by becoming hubs for smart and low-carbon lifestyles. In this context, a stronger linkage between greenhouse gas emissions and urban development and policy-making seems promising. Therefore, simple approaches are needed to objectively identify crucial emission drivers for deriving appropriate emission reduction strategies. In analyzing 44 European cities, the authors investigate possible socioeconomic and spatial determinants of urban greenhouse gas emissions. Multiple statistical analyses reveal that the average household size and the edge density of discontinuous dense urban fabric explain up to 86% of the total variance of greenhouse gas emissions of EU cities (when controlled for varying electricity carbon intensities). Finally, based on these findings, a multiple regression model is presented to determine greenhouse gas emissions. It is independently evaluated with ten further EU cities. The reliance on only two indicators shows that the model can be easily applied in addressing important greenhouse gas emission sources of European urbanites, when varying power generations are considered. This knowledge can help cities develop adequate climate change mitigation strategies and promote respective policies on the EU or the regional level. The results can further be used to derive first estimates of urban greenhouse gas emissions, if no other analyses are available.

  19. Temperature and moisture effects on greenhouse gas emissions from deep active-layer boreal soils

    Energy Technology Data Exchange (ETDEWEB)

    Bond-Lamberty, Benjamin; Smith, Ashly P.; Bailey, Vanessa L.

    2016-12-21

    Rapid climatic changes, rising air temperatures, and increased fires are expected to drive permafrost degradation and alter soil carbon (C) cycling in many high-latitude ecosystems. How these soils will respond to changes in their temperature, moisture, and overlying vegetation is highly uncertain, but critical to understand given the large soil C stocks in these regions. We used a laboratory experiment to examine how temperature and moisture control CO2 and CH4 emissions from mineral soils sampled from the bottom of the annual active layer, i.e. directly above permafrost, in an Alaskan boreal forest. Gas emissions from thirty cores, subjected to two temperatures and either field moisture conditions or experimental drought, were tracked over a 100-day incubation; we also measured a variety of physical and chemical characteristics of the cores. Gravimetric water content was 0.31 ± 0.12 (unitless) at the beginning of the incubation; cores at field moisture were unchanged at the end, but drought cores had declined to 0.06 ± 0.04. Carbon dioxide fluxes were strongly influenced by incubation chamber temperature, core water content, and percent soil nitrogen, and had a temperature sensitivity (i.e. Q10) of 1.3 and 1.9 for the field moisture and drought treatments, respectively. Methane emissions were most strongly correlated with percent nitrogen, but neither temperature nor water content was a significant first-order predictor of CH4 fluxes. The cumulative production of C from CO2 was over six orders of magnitudes higher than that from CH4. These results suggest that deep active-layer soils may be much more sensitive to changes in moisture than to temperature, a critical factor as discontinuous permafrost melts in interior Alaska. Deep but unfrozen high-latitude soils have been shown to be strongly affected by long-term experimental warming, and these results provide insight into their future dynamics and feedback potential with future climate change.

  20. The Greenhouse and Anti-Greenhouse Effects on Titan

    Science.gov (United States)

    McKay, C. P.; Cuzzi, Jeffrey N. (Technical Monitor)

    1994-01-01

    Titan is the largest moon of Saturn and is the only moon in the solar system with a substantial atmosphere. Its atmosphere is mostly made of nitrogen, with a few percent CH4, 0.1% H2 and an uncertain level of Ar (less than 10%). The surface pressure is 1.5 atms and the surface temperature is 95 K, decreasing to 71 at the tropopause before rising to stratospheric temperatures of 180 K. In pressure and composition Titan's atmosphere is the closest twin to Earth's. The surface of Titan remains unknown, hidden by the thick smog layer, but it may be an ocean of liquid methane and ethane. Titan's atmosphere has a greenhouse effect which is much stronger than the Earth's - 92% of the surface warming is due to greenhouse radiation. However an organic smog layer in the upper atmosphere produces an anti-greenhouse effect that cuts the greenhouse warming in half - removing 35% of the incoming solar radiation. Models suggest that during its formation Titan's atmosphere was heated to high temperatures due to accretional energy. This was followed by a cold Triton-like period which gradually warmed to the present conditions. The coupled greenhouse and haze anti-greenhouse may be relevant to recent suggestions for haze shielding of a CH4 - NH3 early atmosphere on Earth or Mars. When the NASA/ESA mission to the Saturn System, Cassini, launches in a few years it will carry a probe that will be sent to the surface of Titan and show us this world that is strange and yet in many ways similar to our own.

  1. A study of direct solar radiation transmission in asymmetrical multi-span greenhouses using scale models and simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, T.; Morales, M.I.; Castilla, N. [CIFA, Granada (Spain); Montero, J.I.; Anton, A. [IRTA, Barcelona (Spain); Sanchez-Guerrero, M.C.; Medrano, E. [CIFA, Almeria (Spain); Hernandez, J. [University of Almeria (Spain)

    2004-06-01

    Direct solar radiation transmission inside scale models of greenhouses with different roof slopes was measured and the results compared with calculations from a simulation model. Seven different roof slopes were tested, which had symmetrical and asymmetrical roof shapes: 8{sup o}-18{sup o}; 18{sup o}-8{sup o}; 27{sup o}-27{sup o}; 27{sup o}-45{sup o}; 36{sup o}-55{sup o}; 45{sup o}-27{sup o}; 55{sup o}-36{sup o} (8{sup o}-18{sup o} denoting that the south-facing slope was 8' and the north-facing one was 18{sup o}). Radiation transmission in scale models was quantified using linear solarimeters that integrated solar radiation along the cross-section of the span. The correlation between measured and calculated hourly and daily mean transmission values was good. Minor differences were attributed to the accumulation of dust and condensation on the scale models, two conditions that were not taken into account in the simulation model. The results of the study showed that direct solar radiation transmission increased considerably as slope increased, up to a value close to 30{sup o}, especially in the winter months in which radiation was most limited. Asymmetrical greenhouses did not always transmit more than symmetrical ones with similar slopes. In the cases studied, the scale model with 27{sup o}-27{sup o} symmetrical roof had the highest winter transmission. The use of scale models allowed different greenhouse structures to be characterised with respect to direct radiation transmission. This method can produce considerable savings of time and money and provides a realistic simulation of radiation transmission in full-scale greenhouses. (author)

  2. Temperature and moisture effects on greenhouse gas emissions from deep active-layer boreal soils

    Science.gov (United States)

    Bond-Lamberty, Ben; Smith, A. Peyton; Bailey, Vanessa

    2016-12-01

    Rapid climatic changes, rising air temperatures, and increased fires are expected to drive permafrost degradation and alter soil carbon (C) cycling in many high-latitude ecosystems. How these soils will respond to changes in their temperature, moisture, and overlying vegetation is uncertain but critical to understand given the large soil C stocks in these regions. We used a laboratory experiment to examine how temperature and moisture control CO2 and CH4 emissions from mineral soils sampled from the bottom of the annual active layer, i.e., directly above permafrost, in an Alaskan boreal forest. Gas emissions from 30 cores, subjected to two temperatures and either field moisture conditions or experimental drought, were tracked over a 100-day incubation; we also measured a variety of physical and chemical characteristics of the cores. Gravimetric water content was 0.31 ± 0.12 (unitless) at the beginning of the incubation; cores at field moisture were unchanged at the end, but drought cores had declined to 0.06 ± 0.04. Daily CO2 fluxes were positively correlated with incubation chamber temperature, core water content, and percent soil nitrogen. They also had a temperature sensitivity (Q10) of 1.3 and 1.9 for the field moisture and drought treatments, respectively. Daily CH4 emissions were most strongly correlated with percent nitrogen, but neither temperature nor water content was a significant first-order predictor of CH4 fluxes. The cumulative production of C from CO2 was over 6 orders of magnitude higher than that from CH4; cumulative CO2 was correlated with incubation temperature and moisture treatment, with drought cores producing 52-73 % lower C. Cumulative CH4 production was unaffected by any treatment. These results suggest that deep active-layer soils may be sensitive to changes in soil moisture under aerobic conditions, a critical factor as discontinuous permafrost thaws in interior Alaska. Deep but unfrozen high-latitude soils have been shown to be

  3. Uncertainty analysis of a coupled ecosystem response model simulating greenhouse gas fluxes from a temperate grassland

    Science.gov (United States)

    Liebermann, Ralf; Kraft, Philipp; Houska, Tobias; Breuer, Lutz; Müller, Christoph; Kraus, David; Haas, Edwin; Klatt, Steffen

    2015-04-01

    Among anthropogenic greenhouse gas emissions, CO2 is the dominant driver of global climate change. Next to its direct impact on the radiation budget, it also affects the climate system by triggering feedback mechanisms in terrestrial ecosystems. Such mechanisms - like stimulated photosynthesis, increased root exudations and reduced stomatal transpiration - influence both the input and the turnover of carbon and nitrogen compounds in the soil. The stabilization and decomposition of these compounds determines how increasing CO2 concentrations change the terrestrial trace gas emissions, especially CO2, N2O and CH4. To assess the potential reaction of terrestrial greenhouse gas emissions to rising tropospheric CO2 concentration, we make use of a comprehensive ecosystem model integrating known processes and fluxes of the carbon-nitrogen cycle in soil, vegetation and water. We apply a state-of-the-art ecosystem model with measurements from a long term field experiment of CO2 enrichment. The model - a grassland realization of LandscapeDNDC - simulates soil chemistry coupled with plant physiology, microclimate and hydrology. The data - comprising biomass, greenhouse gas emissions, management practices and soil properties - has been attained from a FACE (Free Air Carbon dioxide Enrichment) experiment running since 1997 on a temperate grassland in Giessen, Germany. Management and soil data, together with weather records, are used to drive the model, while cut biomass as well as CO2 and N2O emissions are used for calibration and validation. Starting with control data from installations without CO2 enhancement, we begin with a GLUE (General Likelihood Uncertainty Estimation) assessment using Latin Hypercube to reduce the range of the model parameters. This is followed by a detailed sensitivity analysis, the application of DREAM-ZS for model calibration, and an estimation of the effect of input uncertainty on the simulation results. Since first results indicate problems with

  4. A Mechanistically Informed User-Friendly Model to Predict Greenhouse Gas (GHG) Fluxes and Carbon Storage from Coastal Wetlands

    Science.gov (United States)

    Abdul-Aziz, O. I.; Ishtiaq, K. S.

    2015-12-01

    We present a user-friendly modeling tool on MS Excel to predict the greenhouse gas (GHG) fluxes and estimate potential carbon sequestration from the coastal wetlands. The dominant controls of wetland GHG fluxes and their relative mechanistic linkages with various hydro-climatic, sea level, biogeochemical and ecological drivers were first determined by employing a systematic data-analytics method, including Pearson correlation matrix, principal component and factor analyses, and exploratory partial least squares regressions. The mechanistic knowledge and understanding was then utilized to develop parsimonious non-linear (power-law) models to predict wetland carbon dioxide (CO2) and methane (CH4) fluxes based on a sub-set of climatic, hydrologic and environmental drivers such as the photosynthetically active radiation, soil temperature, water depth, and soil salinity. The models were tested with field data for multiple sites and seasons (2012-13) collected from the Waquoit Bay, MA. The model estimated the annual wetland carbon storage by up-scaling the instantaneous predicted fluxes to an extended growing season (e.g., May-October) and by accounting for the net annual lateral carbon fluxes between the wetlands and estuary. The Excel Spreadsheet model is a simple ecological engineering tool for coastal carbon management and their incorporation into a potential carbon market under a changing climate, sea level and environment. Specifically, the model can help to determine appropriate GHG offset protocols and monitoring plans for projects that focus on tidal wetland restoration and maintenance.

  5. Model of Emissions of Greenhouse Gases (Ghg's in the Oil and Gas Industry

    Directory of Open Access Journals (Sweden)

    Amarildo da Cruz Fernandes

    2012-06-01

    Full Text Available The warming of Earth's atmosphere is a natural phenomenon and necessary to sustain life on the planet, being caused by the balance between the electromagnetic radiation received by the Earth from the Sun and the infrared radiation emitted by the Earth back into space. Since the mid-eighteenth century, with the advent of the Industrial Revolution and the consequent increase in burning fossil fuels, changes in land use and agriculture, the concentrations of carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O has increased significantly. By the year 2010, the concentrations of these three gases showed increments respectively in the order of 39%, 158% and 20% (WMO 2009, 2010 and 2011. Such increases in the concentrations of these gases are changing the Earth's radioactive balance, intensifying the natural greenhouse effect, which over millions of years has been essential to support life on the planet. The main objective of this paper is to present the development of a model based on the language of System Dynamics (SD, of how the emission of Greenhouse Gases (GHGs is in complex installations Exploration and Production (E & P of oil and gas. To illustrate one of the results of this modeling process a computer simulation was performed involving emissions from production estimate for the Pilot Production System and Drainage Area Tupi - Tupi Pilot (ICF, 2008.

  6. Testing two models for the estimation of leaf stomatal conductance in four greenhouse crops cucumber, chrysanthemum, tulip and lilium

    NARCIS (Netherlands)

    Li, G.; Lin, L.; Dong, Y.; An, D.; Li, Y.; Luo, W.; Yin, X.; Li, W.; Shao, J.; Zhou, Y.; Dai, J.; Chen, W.; Zhao, C.

    2012-01-01

    Estimating leaf stomatal conductance for CO2 diffusion (gsc) is pivotal for further estimation of crop transpiration as well as energy and mass balances between air and plant in greenhouses. In this study, we tested two models, i.e. the Jarvis model and a new version of BWB–Leuning model (BWB–Leunin

  7. Greenhouse gas mitigation options in the forestry sector of The Gambia: Analysis based on COMAP model

    Energy Technology Data Exchange (ETDEWEB)

    Jallow, B.P.

    1996-12-31

    Results of the 1993 Greenhouse Gas Emissions Inventory of The Gambia showed net CO{sub 2} emissions of over (1.66 x 10{sup 6} tons) and 1% was due to uptake by plantations (0.01 x 10{sup 6} tons). This is a clear indication that there is need to identify changes in the land-use policy, law and tenure that discourages forest clearing at the same time significantly influencing the sustainable distribution of land among forestry, rangeland and livestock, and agriculture. About 11% of the total area of The Gambia is either fallow or barren flats that once supported vegetation and hence is still capable of supporting vegetation. The US Country Study Programme has provided the Government of The Gambia through the National Climate Committee funds to conduct Assessment of Mitigation Options to Reduce Greenhouse Gas Emissions. The Forestry Sector is one area for which assessment is being conducted. The assessment is expected to end in September 1996. The Comprehensive Mitigation Analysis Process (COMAP) is one of the Models supplied to the National Climate Committee by the Lawrence Berkeley Laboratory, on behalf of the US Country Study Programme, and is being used to conduct the analysis in The Gambia.

  8. Human intake fractions of pesticides via greenhouse tomato consumption: comparing model estimates with measurements for Captan.

    Science.gov (United States)

    Juraske, R; Antón, A; Castells, F; Huijbregts, M A J

    2007-04-01

    Human intake due to pesticide residues in food commodities can be much higher than those related to water consumption and air inhalation, stressing the importance to correctly estimate pesticide uptake into plants and predict subsequent intake by humans. We calculated the human intake fraction of captan via tomato consumption taking into account the time between pesticide application and harvest, the time between harvest and consumption, the absorption of spray deposit on plant surfaces, transfer properties through the cuticle, degradation inside the plant and loss due to food processing. Human population intake fractions due to ingestion were calculated for complete, washed and peeled tomatoes. The calculated intake fractions were compared with measurements derived from an experimental setup in a Mediterranean greenhouse. The fraction of captan applied in the greenhouse as plant treatment that eventually is ingested by the human population is on average 10(-2)-10(-5), depending on the time between pesticide application and ingestion of tomatoes and the processing step considered. Model and experimentally derived intake fractions deviated less than a factor of 2 for complete and washed tomatoes and a factor of 3 for peeled tomatoes. Intake fractions due to air inhalation and consumption of drinking water are expected to be significantly lower (5-9 orders of magnitude) than those induced by the intake of tomatoes in this case study.

  9. Collaborative Emission Reduction Model Based on Multi-Objective Optimization for Greenhouse Gases and Air Pollutants.

    Directory of Open Access Journals (Sweden)

    Qing-chun Meng

    Full Text Available CO2 emission influences not only global climate change but also international economic and political situations. Thus, reducing the emission of CO2, a major greenhouse gas, has become a major issue in China and around the world as regards preserving the environmental ecology. Energy consumption from coal, oil, and natural gas is primarily responsible for the production of greenhouse gases and air pollutants such as SO2 and NOX, which are the main air pollutants in China. In this study, a mathematical multi-objective optimization method was adopted to analyze the collaborative emission reduction of three kinds of gases on the basis of their common restraints in different ways of energy consumption to develop an economic, clean, and efficient scheme for energy distribution. The first part introduces the background research, the collaborative emission reduction for three kinds of gases, the multi-objective optimization, the main mathematical modeling, and the optimization method. The second part discusses the four mathematical tools utilized in this study, which include the Granger causality test to analyze the causality between air quality and pollutant emission, a function analysis to determine the quantitative relation between energy consumption and pollutant emission, a multi-objective optimization to set up the collaborative optimization model that considers energy consumption, and an optimality condition analysis for the multi-objective optimization model to design the optimal-pole algorithm and obtain an efficient collaborative reduction scheme. In the empirical analysis, the data of pollutant emission and final consumption of energies of Tianjin in 1996-2012 was employed to verify the effectiveness of the model and analyze the efficient solution and the corresponding dominant set. In the last part, several suggestions for collaborative reduction are recommended and the drawn conclusions are stated.

  10. Collaborative Emission Reduction Model Based on Multi-Objective Optimization for Greenhouse Gases and Air Pollutants.

    Science.gov (United States)

    Meng, Qing-chun; Rong, Xiao-xia; Zhang, Yi-min; Wan, Xiao-le; Liu, Yuan-yuan; Wang, Yu-zhi

    2016-01-01

    CO2 emission influences not only global climate change but also international economic and political situations. Thus, reducing the emission of CO2, a major greenhouse gas, has become a major issue in China and around the world as regards preserving the environmental ecology. Energy consumption from coal, oil, and natural gas is primarily responsible for the production of greenhouse gases and air pollutants such as SO2 and NOX, which are the main air pollutants in China. In this study, a mathematical multi-objective optimization method was adopted to analyze the collaborative emission reduction of three kinds of gases on the basis of their common restraints in different ways of energy consumption to develop an economic, clean, and efficient scheme for energy distribution. The first part introduces the background research, the collaborative emission reduction for three kinds of gases, the multi-objective optimization, the main mathematical modeling, and the optimization method. The second part discusses the four mathematical tools utilized in this study, which include the Granger causality test to analyze the causality between air quality and pollutant emission, a function analysis to determine the quantitative relation between energy consumption and pollutant emission, a multi-objective optimization to set up the collaborative optimization model that considers energy consumption, and an optimality condition analysis for the multi-objective optimization model to design the optimal-pole algorithm and obtain an efficient collaborative reduction scheme. In the empirical analysis, the data of pollutant emission and final consumption of energies of Tianjin in 1996-2012 was employed to verify the effectiveness of the model and analyze the efficient solution and the corresponding dominant set. In the last part, several suggestions for collaborative reduction are recommended and the drawn conclusions are stated.

  11. Methane and Other Greenhouse Gases in the Arctic - Measurements, Process Studies and Modelling (MAMM)

    Science.gov (United States)

    Pyle, J. A.; Warwick, N. J.; Cain, M.; Hayman, G.; Skiba, U.; Drewer, J.; Dinsmore, K.; George, C.; Nisbet, E. G.; Lowry, D.; Fisher, R. E.; France, J. L.; Lanoiselle, M.; Brownlow, R. B.; Allen, G.; Bower, K.; Gallagher, M. W.; Percival, C.; Illingworth, S. M.; Jones, B.; Muller, J.; O'Shea, S.; Manning, A. C.; Kozlova, E.; Manning, A. J.; Smith, M.; Anderson, D.; Bauguitte, S.

    2013-12-01

    The Arctic is a major source of atmospheric methane and other greenhouse gases, of both natural and anthropogenic origin. Arctic greenhouse gas sources need to be quantified, by strength, geographic location, character (e.g. wetlands, gas fields, hydrates), and by temporal variation (daily, seasonally and annually), and their vulnerability to change assessed. To this end, the MAMM project was commissioned as part of the UK NERC Arctic Research Programme. It involves an integrated series of measurement and modelling activities. Analysis of atmospheric gas concentrations, isotopic character, and source fluxes, are being made from both the ground and from the NERC FAAM (Facility for Airborne Atmospheric Measurements) aircraft. The measurements (historic and new) are being interpreted using a suite of models (trajectory, forward and inverse) to improve the understanding of the local/regional scale, placing the role of Arctic emissions in the context of large-scale global atmospheric change. The first measurement campaign was held in August 2012. Surface flux measurements were made at the Sodankylä research station in Finland, together with in-situ surface and aircraft measurements over a wider area. In addition to flights over the Sodankylä wetlands, the aircraft also flew out to Svalbard, Norway to investigate marine sources of methane. Further campaigns are taking place in Sweden in August and September 2013. The initial measurements have been used to infer wetland emission fluxes and confirm that Scandinavian wetlands are a major source of methane in this region (see posters by Fisher et al, O'Shea et al). The aircraft also measured a high-methane plume over the sea between mainland Norway and Svalbard, which was likely advected from mainland wetland sources (see poster by France et al). Results from the field campaigns will be presented, alongside results from the NAME model (the UK Met Office's Numerical Atmospheric dispersion Modelling Environment) to help

  12. Validation of Growth and Nutrient Uptake Models for Tomato on a Gravelly South Florida Soil Under Greenhouse Conditions

    Institute of Scientific and Technical Information of China (English)

    D.A.CHIN; X.H.FAN; Y.C.LI

    2011-01-01

    The Soil and Water Assessment Tool (SWAT) has been widely used throughout the world to model crop growth and nutrient uptake in various types of soils. A greenhouse experiment was performed to validate the process equations embedded in SWAT for describing the growth and nutrient uptake of tomatoes in south Florida. The scaled growth curve of greenhouse-grown tomatoes was in close agreement with the theoretical model for field conditions, with the scaling factors being the maximum canopy height and the potential heat units. Similarly, the scaled leaf area index (LAI) growth curve and the scaled root depth curve for greenhousegrown tomatoes agreed with the SWAT functions, with the scaling factors being the maximum LAI and maximum root depth. The greenhouse experiment confirmed that the growth of biomass is a linear function of the intercepted photosynthetically active radiation.The fractions of nutrients in the plant biomass under greenhouse conditions were found to be on the order of 60% of those fractions observed in the field. Values of the initial P distribution (0.2 mg kg-1), initial ratio of mineral stable P to mineral active P (50:1),and initial ratio of humic N to humic P (2.4:1) were determined from soil measurements and can be used for field simulations. The conventional saturation-excess model for soil-water percolation was used to predict the movement of water in the top 10 cm of the greenhouse containers and the results agreed well with measurements.

  13. Estimating greenhouse gas emissions of European cities — Modeling emissions with only one spatial and one socioeconomic variable

    Energy Technology Data Exchange (ETDEWEB)

    Baur, Albert H., E-mail: Albert.H.Baur@campus.tu-berlin.de; Lauf, Steffen; Förster, Michael; Kleinschmit, Birgit

    2015-07-01

    Substantive and concerted action is needed to mitigate climate change. However, international negotiations struggle to adopt ambitious legislation and to anticipate more climate-friendly developments. Thus, stronger actions are needed from other players. Cities, being greenhouse gas emission centers, play a key role in promoting the climate change mitigation movement by becoming hubs for smart and low-carbon lifestyles. In this context, a stronger linkage between greenhouse gas emissions and urban development and policy-making seems promising. Therefore, simple approaches are needed to objectively identify crucial emission drivers for deriving appropriate emission reduction strategies. In analyzing 44 European cities, the authors investigate possible socioeconomic and spatial determinants of urban greenhouse gas emissions. Multiple statistical analyses reveal that the average household size and the edge density of discontinuous dense urban fabric explain up to 86% of the total variance of greenhouse gas emissions of EU cities (when controlled for varying electricity carbon intensities). Finally, based on these findings, a multiple regression model is presented to determine greenhouse gas emissions. It is independently evaluated with ten further EU cities. The reliance on only two indicators shows that the model can be easily applied in addressing important greenhouse gas emission sources of European urbanites, when varying power generations are considered. This knowledge can help cities develop adequate climate change mitigation strategies and promote respective policies on the EU or the regional level. The results can further be used to derive first estimates of urban greenhouse gas emissions, if no other analyses are available. - Highlights: • Two variables determine urban GHG emissions in Europe, assuming equal power generation. • Household size, inner-urban compactness and power generation drive urban GHG emissions. • Climate policies should consider

  14. Process-based modeling of the control of beet armyworm, Spodoptera exigua, with baculoviruses in greenhouse chrysanthemum

    NARCIS (Netherlands)

    Bianchi, F.J.J.A.

    2001-01-01

    This thesis describes the development of a process-based simulation model for the population dynamics of beet armyworm, Spodoptera exigua , and baculoviruses in greenhouse chrysanthemum. The model (BACSIM) has been validated for two baculoviruses with clear differences in biological characteristics,

  15. Greenhouse crop residues: Energy potential and models for the prediction of their higher heating value

    Energy Technology Data Exchange (ETDEWEB)

    Callejon-Ferre, A.J.; Lopez-Martinez, J.A.; Manzano-Agugliaro, F. [Departamento de Ingenieria Rural, Universidad de Almeria, Ctra. Sacramento s/n, La Canada de San Urbano, 04120 Almeria (Spain); Velazquez-Marti, B. [Departamento de Ingenieria Rural y Agroalimentaria, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2011-02-15

    Almeria, in southeastern Spain, generates some 1,086,261 t year{sup -1} (fresh weight) of greenhouse crop (Cucurbita pepo L., Cucumis sativus L., Solanum melongena L., Solanum lycopersicum L., Phaseoulus vulgaris L., Capsicum annuum L., Citrillus vulgaris Schrad. and Cucumis melo L.) residues. The energy potential of this biomass is unclear. The aim of the present work was to accurately quantify this variable, differentiating between crop species while taking into consideration the area they each occupy. This, however, required the direct analysis of the higher heating value (HHV) of these residues, involving very expensive and therefore not commonly available equipment. Thus, a further aim was to develop models for predicting the HHV of these residues, taking into account variables measured by elemental and/or proximate analysis, thus providing an economically attractive alternative to direct analysis. All the analyses in this work involved the use of worldwide-recognised standards and methods. The total energy potential for these plant residues, as determined by direct analysis, was 1,003,497.49 MW h year{sup -1}. Twenty univariate and multivariate equations were developed to predict the HHV. The R{sup 2} and adjusted R{sup 2} values obtained for the univariate and multivariate models were 0.909 and 0.946 or above respectively. In all cases, the mean absolute percentage error varied between 0.344 and 2.533. These results show that any of these 20 equations could be used to accurately predict the HHV of crop residues. The residues produced by the Almeria greenhouse industry would appear to be an interesting source of renewable energy. (author)

  16. Modeling the greenhouse gas budget of straw returning in China: feasibility of mitigation and countermeasures.

    Science.gov (United States)

    Lu, Fei; Wang, Xiao-Ke; Han, Bing; Ouyang, Zhi-Yun; Zheng, Hua

    2010-05-01

    Straw returning is considered to be one of the most promising carbon sequestration measures in China's cropland. A compound model, namely "Straw Returning and Burning Model-Expansion" (SRBME), was built to estimate the net mitigation potential, economic benefits, and air pollutant reduction of straw returning. Three scenarios, that is, baseline, "full popularization of straw returning (FP)," and "full popularization of straw returning and precision fertilization (FP + P)," were set to reflect popularization of straw returning. The results of the SRBME indicated that (1) compared with the soil carbon sequestration of 13.37 Tg/yr, the net mitigation potentials, which were 6.328 Tg/yr for the FP scenario and 9.179 Tg/yr for the FP + P scenario, had different trends when the full budget of the greenhouse gases was considered; (2) when the feasibility in connection with greenhouse gas (GHG) mitigation, economic benefits, and environmental benefits was taken into consideration, straw returning was feasible in 15 provinces in the FP scenario, with a total net mitigation potential of 7.192 TgCe/yr and the total benefits of CNY 1.473 billion (USD 216.6 million); (3) in the FP + P scenario, with the implementation of precision fertilization, straw returning was feasible in 26 provinces with a total net mitigation potential of 10.39 TgCe/yr and the total benefits of CNY 5.466 billion (USD 803.8 million); (4) any extent of change in the treatment of straw from being burnt to being returned would contribute to air pollution reduction; (5) some countermeasures, such as CH(4) reduction in rice paddies, precision fertilization, financial support, education and propaganda, would promote the feasibility of straw returning as a mitigation measure.

  17. A generic model for estimating biomass accumulation and greenhouse gas emissions from perennial crops

    Science.gov (United States)

    Ledo, Alicia; Heathcote, Richard; Hastings, Astley; Smith, Pete; Hillier, Jonathan

    2017-04-01

    Agriculture is essential to maintain humankind but is, at the same time, a substantial emitter of greenhouse gas (GHG) emissions. With a rising global population, the need for agriculture to provide secure food and energy supply is one of the main human challenges. At the same time, it is the only sector which has significant potential for negative emissions through the sequestration of carbon and offsetting via supply of feedstock for energy production. Perennial crops accumulate carbon during their lifetime and enhance organic soil carbon increase via root senescence and decomposition. However, inconsistency in accounting for this stored biomass undermines efforts to assess the benefits of such cropping systems when applied at scale. A consequence of this exclusion is that efforts to manage this important carbon stock are neglected. Detailed information on carbon balance is crucial to identify the main processes responsible for greenhouse gas emissions in order to develop strategic mitigation programs. Perennial crops systems represent 30% in area of total global crop systems, a considerable amount to be ignored. Furthermore, they have a major standing both in the bioenergy and global food industries. In this study, we first present a generic model to calculate the carbon balance and GHGs emissions from perennial crops, covering both food and bioenergy crops. The model is composed of two simple process-based sub-models, to cover perennial grasses and other perennial woody plants. The first is a generic individual based sub-model (IBM) covering crops in which the yield is the fruit and the plant biomass is an unharvested residue. Trees, shrubs and climbers fall into this category. The second model is a generic area based sub-model (ABM) covering perennial grasses, in which the harvested part includes some of the plant parts in which the carbon storage is accounted. Most second generation perennial bioenergy crops fall into this category. Both generic sub-models

  18. Modelling room temperature ionic liquids.

    Science.gov (United States)

    Bhargava, B L; Balasubramanian, Sundaram; Klein, Michael L

    2008-08-07

    Room temperature ionic liquids (IL) composed of organic cations and inorganic anions are already being utilized for wide-ranging applications in chemistry. Complementary to experiments, computational modelling has provided reliable details into the nature of their interactions. The intra- and intermolecular structures, dynamic and transport behaviour and morphologies of these novel liquids have also been explored using simulations. The current status of molecular modelling studies is presented along with the prognosis for future work in this area.

  19. Modelling water temperature in TOXSWA

    NARCIS (Netherlands)

    Jacobs, C.M.J.; Deneer, J.W.; Adriaanse, P.I.

    2010-01-01

    A reasonably accurate estimate of the water temperature is necessary for a good description of the degradation of plant protection products in water which is used in the surface water model TOXSWA. Based on a consideration of basic physical processes that describe the influence of weather on the

  20. Modeling greenhouse gas emissions and nutrient transport in managed arable soils with a fully coupled hydrology-biogeochemical modeling system

    Science.gov (United States)

    Haas, Edwin; Klatt, Steffen; Kiese, Ralf; Butterbach-Bahl, Klaus; Kraft, Philipp; Breuer, Lutz

    2015-04-01

    The use of mineral nitrogen fertilizer sustains the global food production and therefore the livelihood of human kind. The rise in world population will put pressure on the global agricultural system to increase its productivity leading most likely to an intensification of mineral nitrogen fertilizer use. The fate of excess nitrogen and its distribution within landscapes is manifold. Process knowledge on the site scale has rapidly grown in recent years and models have been developed to simulate carbon and nitrogen cycling in managed ecosystems on the site scale. Despite first regional studies, the carbon and nitrogen cycling on the landscape or catchment scale is not fully understood. In this study we present a newly developed modelling approach by coupling the fully distributed hydrology model CMF (catchment modelling framework) to the process based regional ecosystem model LandscapeDNDC for the investigation of hydrological processes and carbon and nitrogen transport and cycling, with a focus on nutrient displacement and resulting greenhouse gas emissions in various virtual landscapes / catchment to demonstrate the capabilities of the modelling system. The modelling system was applied to simulate water and nutrient transport at the at the Yanting Agro-ecological Experimental Station of Purple Soil, Sichuan province, China. The catchment hosts cypress forests on the outer regions, arable fields on the sloping croplands cultivated with wheat-maize rotations and paddy rice fields in the lowland. The catchment consists of 300 polygons vertically stratified into 10 soil layers. Ecosystem states (soil water content and nutrients) and fluxes (evapotranspiration) are exchanged between the models at high temporal scales (hourly to daily) forming a 3-dimensional model application. The water flux and nutrients transport in the soil is modelled using a 3D Richards/Darcy approach for subsurface fluxes with a kinematic wave approach for surface water runoff and the

  1. Optimizing illumination in the greenhouse using a 3D model of tomato and a ray tracer

    NARCIS (Netherlands)

    Visser, de P.H.B.; Buck-Sorlin, G.H.; Heijden, van der G.W.A.M.

    2014-01-01

    Reduction of energy use for assimilation lighting is one of the most urgent goals of current greenhouse horticulture in the Netherlands. In recent years numerous lighting systems have been tested in greenhouses, yet their efficiency has been very difficult to measure in practice. This simulation stu

  2. Resources use and greenhouse gas emissions in urban economy: Ecological input-output modeling for Beijing 2002

    Science.gov (United States)

    Zhou, S. Y.; Chen, H.; Li, S. C.

    2010-10-01

    The embodiment of natural resources and greenhouse gas emissions for the urban economy of Beijing economy 2002 by a physical balance modeling is carried out based on an extension of the economic input-output table into an ecological one integrating the economy with its various environmental driving forces. Included resources and greenhouse gas emissions belong to six categories as energy resources in terms of primary energy and secondary energy; water resource; emissions of CO2, CH4, and N2O; exergy in terms of energy sources, biological resources and minerals; and solar emergy and cosmic emergy in terms of climate resources, soil, energy sources, and minerals.

  3. GREENHOUSE BRITAIN

    Directory of Open Access Journals (Sweden)

    David Haley

    2008-10-01

    Full Text Available We believe that the cultural landscape is largely formed by the dominant cultures of a place. “It is formed by a sometimes conflicted, sometimes consensual discourse or narrative from an array of stories, observations and intentions, first spoken by people of these dominant cultures and thereafter enacted on the ground. To our view, such a story has certain fluidity about it, and may change directions for any number of reasons. This work, Greenhouse Britain, is designed literally to express what the risingof waters would mean to the landscape of the island. It takes the 3 positions of defense, withdrawal and then defense, withdrawal to the high grounds. We suggest that the existing plans for greenhouse emissions control will be insufficient to keep temperature rise at 2° or less. In fact, we believe that the tipping point is past. In this context, the rising ocean becomes a form determinant. By “form determinant”, we mean, the rising ocean will determine many of the new forms that culture, industry and many other elements of civilization will have to take. There is another piece of this picture that we wish to give Voice to. That is up until this present rising of the world oceans, the creators of Western civilization have held and enacted the belief that all limitations in the physical world, particularly in the ecological world are there to be used and overcome. We think that the rising ocean is an opportunity for transformation, but it is exactly the reverse of a new frontier to overcome from civilization’s perspective. Now, from the ocean’s perspective, its boundary is perhaps a continuing, evolving transforming new frontier. Therefore, assuming a rapid rise of waters, even for a modest 5 meters in 100 years, there are apparently no models of precedence, no information, design, nor planning on the table, with the exception of ocean defenses and typical development models, albeit more energy efficient ones. It is the intention of

  4. Greenhouse gases from wastewater treatment — A review of modelling tools

    Energy Technology Data Exchange (ETDEWEB)

    Mannina, Giorgio, E-mail: giorgio.mannina@unipa.it [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90100 Palermo (Italy); Ekama, George [Water Research Group, Department of Civil Engineering, University of Cape Town, Rondebosch, 7700 Cape (South Africa); Caniani, Donatella [Department of Engineering and Physics of the Environment, University of Basilicata, viale dell' Ateneo Lucano 10, 85100 Potenza (Italy); Cosenza, Alida [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90100 Palermo (Italy); Esposito, Giovanni [Department of Civil and Mechanical Engineering, University of Cassino and the Southern Lazio, Via Di Biasio, 43, 03043 Cassino, FR (Italy); Gori, Riccardo [Department of Civil and Environmental Engineering, University of Florence, Via Santa Marta 3, 50139 Florence (Italy); Garrido-Baserba, Manel [Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175 (United States); Rosso, Diego [Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175 (United States); Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175 (United States); Olsson, Gustaf [Department of Industrial Electrical Engineering and Automation (IEA), Lund University, Box 118, SE-22100 Lund (Sweden)

    2016-05-01

    Nitrous oxide, carbon dioxide and methane are greenhouse gases (GHG) emitted from wastewater treatment that contribute to its carbon footprint. As a result of the increasing awareness of GHG emissions from wastewater treatment plants (WWTPs), new modelling, design, and operational tools have been developed to address and reduce GHG emissions at the plant-wide scale and beyond. This paper reviews the state-of-the-art and the recently developed tools used to understand and manage GHG emissions from WWTPs, and discusses open problems and research gaps. The literature review reveals that knowledge on the processes related to N{sub 2}O formation, especially due to autotrophic biomass, is still incomplete. The literature review shows also that a plant-wide modelling approach that includes GHG is the best option for the understanding how to reduce the carbon footprint of WWTPs. Indeed, several studies have confirmed that a wide vision of the WWPTs has to be considered in order to make them more sustainable as possible. Mechanistic dynamic models were demonstrated as the most comprehensive and reliable tools for GHG assessment. Very few plant-wide GHG modelling studies have been applied to real WWTPs due to the huge difficulties related to data availability and the model complexity. For further improvement in GHG plant-wide modelling and to favour its use at large real scale, knowledge of the mechanisms involved in GHG formation and release, and data acquisition must be enhanced. - Highlights: • The state of the art in GHG production/emission/modelling from WWTPs was outlined. • Detailed mechanisms of N{sub 2}O production by AOB are still not completely known. • N{sub 2}O modelling could be improved considering both AOB pathways contribution. • To improve protocols the regulatory framework among countries has to be equalized. • Plant-wide modelling can help modeller/engineer/operator to reduce GHG emissions.

  5. Infrared photometry and spectrophotometry of Titan. [for atmospheric brightness temperature model

    Science.gov (United States)

    Morrison, D.

    1974-01-01

    The wide variation in infrared brightness temperature of Titan is explained in terms of a greenhouse effect. Radiometric observations in the infrared and microwave frequencies indicate an alternate hot atmospheric model. Methane, ammonia, hydrogen atoms, and nitrogen atoms are suggested as main constituents for the Titan atmosphere.

  6. Greener greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Paksoy, Halime; Turgut, Bekir; Beyhan, Beyza; Dasgan, H. Yildiz; Evliya, Hunay; Abak, Kazim; Bozdag, Saziye

    2010-09-15

    Agricultural greenhouses are solution to the increased demand for higher production yields, facilitating off season cultivation and allowing the growth of certain varieties in areas where it was not possible earlier. Heating and/or cooling system, required to maintain the inside micro-climate in greenhouses mostly rely on fossil fuels and/or electricity. This paper aims to discuss the 'greener' solutions for heating and cooling systems of greenhouses based on different thermal energy storage concepts. Results from a greenhouse Aquifer Thermal Energy Storage (ATES) application in Turkey producing tomatoes with zero fossil fuels and up to 40% higher yield are presented.

  7. Energy saving in greenhouses can be obtained by energy balance-controlled screens

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, N. E. (Univ. of Aarhus, Faculty of Agricultural Sciences, Dept. of Horticulture, Aarslev (Denmark)), e-mail: niels.andersson@agrsci.dk

    2011-03-15

    The energy screens in two greenhouses, one clad with double acrylic and one with single glass, were controlled by an energy balance model. The parameters in the model were heat transmission coefficients, air temperature in the greenhouse and outdoors, irradiance and a single constant for the solar energy efficiency. The energy consumption, screen movements and daily light integral were compared with a glass greenhouse in which the energy screens were controlled by irradiance. In the greenhouse with light-controlled screens the set point for opening and closing of the screens was 5 Wm-2. The energy-saving screens controlled by the energy balance model opened later and closed earlier than in the greenhouse with light-controlled screens. When using the energy balance model the energy saving was 14% for the glass greenhouse and 41% for the double acrylic greenhouse compared with the glass greenhouse with light-controlled screens. The air temperature was on average similar in the three greenhouses, but when the screens were controlled by energy balance the daily light integral was approximately 10% lower and the number of hours the screens were closed was prolonged with 35% for the glass-covered greenhouse and 25% for the double acrylic-covered greenhouse compared with the greenhouse with light-controlled screens. Energy peaks in connection with operation of the screens were not reduced. During the experiment Begonia elatior, Dendranthema grandiflora (Chrysanthemum), Hedera helix, Helianthus annuus, Gerbera jamesonii and Kalanchoe blossfeldiana were grown in the greenhouses. There was a trend in prolongation of the production time when the plants were grown in the glass greenhouse with energy balance control of the screens. A lower number of flowers or inflorescences were observed for some of the plant species produced in the greenhouses with energy balance-controlled screens

  8. 77 FR 68070 - 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel...

    Science.gov (United States)

    2012-11-15

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 85, 86, and 600 DEPARTMENT OF TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Parts 523, 531, 533, 536, and 537 RIN 2060-AQ54; RIN 2127-AK79 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas...

  9. Space-borne remote sensing with active optical instruments for the measurement of temperature, pressure, ozone and the greenhouse gases CO2, CH4, and N2O

    Science.gov (United States)

    Ehret, G.; Fix, A.; Kiemle, C.; Wirth, M.

    Lidar Light Detection and Ranging is regarded as an innovative component of the global observing system It offers the possibility to directly sample the four-dimensional variability of the atmosphere with unprecedented accuracy and spatial resolution In Europe space-borne lidar systems have been the subject of extensive investigations since mid 1970 s resulting in mission and instrument concepts such as ATLID a backscatter lidar for aerosol and clouds for the EarthCARE mission or ALADIN a Doppler wind lidar considered for the ADM Aeolus mission Major advances particularly in humidity profiling are expected from the space-borne Differential Absorption Lidar DIAL being the Core instrument of the WALES Water Vapour Lidar Experiment in Space mission which was studied up to a level of Phase A In this presentation we report on the background definition of a future lidar system capable of monitoring the greenhouse gases carbon dioxide CO 2 methane CH 4 and nitrous oxide N 2 O stratospheric and tropospheric ozone O 3 and the meteorological parameter pressure p and temperature T The idea of this study which was initiated by the European Space Agency ESA was to select one or two candidate instruments for follow-on activities on sensor and mission level For each parameter appropriate performance models of active optical instruments either for range-resolved or for total column measurements were defined and implemented as computer codes for parametric analysis The sampling strategy and error characteristics for the

  10. Modelling of salad plants growth and physiological status in vitamin space greenhouse during lighting regime optimization

    Science.gov (United States)

    Konovalova, Irina; Berkovich, Yuliy A.; Smolyanina, Svetlana; Erokhin, Alexei; Yakovleva, Olga; Lapach, Sergij; Radchenko, Stanislav; Znamenskii, Artem; Tarakanov, Ivan

    2016-07-01

    The efficiency of the photoautotrophic element as part of bio-engineering life-support systems is determined substantially by lighting regime. The artificial light regime optimization complexity results from the wide range of plant physiological functions controlled by light: trophic, informative, biosynthetical, etc. An average photosynthetic photon flux density (PPFD), light spectral composition and pulsed light effects on the crop growth and plant physiological status were studied in the multivariate experiment, including 16 independent experiments in 3 replicates. Chinese cabbage plants (Brassica chinensis L.), cultivar Vesnianka, were grown during 24 days in a climatic chamber under white and red light-emitting diodes (LEDs): photoperiod 24 h, PPFD from 260 to 500 µM/(m ^{2}*s), red light share in the spectrum varying from 33% to 73%, pulsed (pulse period from 30 to 501 µs) and non-pulsed lighting. The regressions of plant photosynthetic and biochemical indexes as well as the crop specific productivity in response to the selected parameters of lighting regime were calculated. Developed models of crop net photosynthesis and dark respiration revealed the most intense gas exchange area corresponding to PPFD level 450 - 500 µM/(m ^{2}*s) with red light share in the spectrum about 60% and the pulse length 30 µs with a pulse period from 300 to 400 µs. Shoot dry weight increased monotonically in response to the increasing PPFD and changed depending on the pulse period under stabilized PPFD level. An increase in ascorbic acid content in the shoot biomass was revealed when increasing red light share in spectrum from 33% to 73%. The lighting regime optimization criterion (Q) was designed for the vitamin space greenhouse as the maximum of a crop yield square on its ascorbic acid concentration, divided by the light energy consumption. The regression model of optimization criterion was constructed based on the experimental data. The analysis of the model made it

  11. Mist greenhouse

    NARCIS (Netherlands)

    Weel, van P.A.; Voogt, J.O.

    2007-01-01

    The present invention relates to a greenhouse system with a climate regulation which is controlled through measuring the stomatal aperture of the plants present in the greenhouse. The regulation mainly consists of controlling a misting installation and optionally of adjusting other, conventional

  12. Does the correlation between solar cycle lengths and Northern Hemisphere land temperatures rule out any significant global warming from greenhouse gases?

    DEFF Research Database (Denmark)

    Laut, Peter; Gundermann, Jesper

    1998-01-01

    Since the discovery of a striking correlation between solar cycle lengths and Northern Hemisphere land temperatures there have been widespread speculations as to whether these findings would rule out any significant contributions to global warming from the enhanced concentrations of greenhouse...... gases. The present analysis shows that a similar degree of correlation is obtained when testing the solar data against a couple of fictitious temperature series representing different global warming trends. Therefore, the correlation cannot be used to estimate the magnitude of a possible contribution...... to global warming from human activities, nor to rule out a sizable contribution from that source....

  13. Does the correlation between solar cycle lengths and Northern Hemisphere land temperatures rule out any significant global warming from greenhouse gases?

    DEFF Research Database (Denmark)

    Laut, Peter; Gundermann, Jesper

    1998-01-01

    Since the discovery of a striking correlation between solar cycle lengths and Northern Hemisphere land temperatures there have been widespread speculations as to whether these findings would rule out any significant contributions to global warming from the enhanced concentrations of greenhouse...... gases. The present analysis shows that a similar degree of correlation is obtained when testing the solar data against a couple of fictitious temperature series representing different global warming trends. Therefore, the correlation cannot be used to estimate the magnitude of a possible contribution...... to global warming from human activities, nor to rule out a sizable contribution from that source....

  14. 基于BP神经网络的杨梅大棚内气温预测模型研究%Simulation and Forecast of Air Temperature inside the Greenhouse Planted Myica rubra Based on BP Neural Network

    Institute of Scientific and Technical Information of China (English)

    金志凤; 符国槐; 黄海静; 潘永地; 杨再强; 李仁忠

    2011-01-01

    利用2009年12月-2010年5月塑料大棚内外观测的气象数据,构建了基于BP神经网络的杨梅生产大棚内的最高、最低气温预测模型,根据逐时转化系数计算出棚内相应的逐时气温,达到逐时预报大棚内气温的目的.通过模拟回代和对独立试验数据的验证,基于BP神经网络模型对大棚内日最低气温、日最高气温和逐时气温预测值与实际值的回归估计标准误差(RMSE)分别为0.8℃、1.4C和0.7℃,精度明显高于同时利用逐步回归法建立的模型.该模型所需参数少,实用性强,模拟精度高,可为设施杨梅气象服务和环境调控提供依据.%The minimum and maximum temperature prediction model inside greenhouse planted Myica rubra was established based on BP neural network, by using meteorological data both inside and outside the greenhouse from December 2009 to June 2010 in Wenzhou of Zhejiang province. Using the independent experimental data and simulation back generations to verify the model,the results indicated that the root mean square error( RMSE) between the predicted value and measured value based on 1: 1 line for the minimum and maximum and hourly inside air temperature were 0. 8℃ ,1.4℃ and 0. 7℃ .respectively. The precision of BP neural network model was higher than that of the stepwise regression model obviously. The model,with few parameters,could predict the greenhouse temperature more accurately .which could provide scientific basis for facility meteorological service and environment regulation of greenhouse Myr-ica rubra cultivation.

  15. Design of Intelligent Temperature and Humidity Control System for Vegetable Greenhouse%蔬菜大棚温湿度智能控制系统设计

    Institute of Scientific and Technical Information of China (English)

    梁万用; 王凯

    2009-01-01

    针对目前蔬菜大棚人工控制的不足,设计了蔬菜大棚温湿度智能控制系统.采用模糊控制理论,对 PID 参数进行实时校正,使系统控制性能处于最优控制状态,实现对蔬菜大棚温湿度的精确控制.试验和实际运行表明,该系统运行可靠,自动化程度高,有利于蔬菜大棚的智能化和统一化管理.%Aiming at the shortcoming of manual control of vegetable greenhouse at present, the intelligent temperature and humidity control system was designed for vegetable greenhouse.Using the fuzzy control theory, the real-time correction was carried on PID's parameters to make the system control capability in the most excellent state.The accurate control of temperature and humidity for vegetable greenhouse was realized.The results of running and experiment indicated that the system was reliable, with high automation degree.It is propitious to centralized and intellectualized management.

  16. Advancement of regional-scale emission mapping of greenhouse gases using anthropogenic emission inventories and a process-based model

    Science.gov (United States)

    Ito, A.; Saito, M.; Hirata, R.; Senda, M.

    2016-12-01

    Emissions of greenhouse gases distribute highly heterogeneously over land surface, including natural sources and sinks and anthropogenic sources. They have also different temporal variations, making it difficult to resolve observed atmospheric signals into specific sources. Advancing the mapping of land surface greenhouse gas sources and sinks is effective to improve credibility of not only bottom-up but also top-down estimates. In this study, we make an attempt to conduct regional-scale evaluation of greenhouse gases using several anthropogenic emission inventories and a process-based model of natural sources and sinks. We compare different inventory data to clarify the uncertainty in regional budget, putting the particular focus on Asian region and countries. The process-based model estimates greenhouse gas budget of forests, other natural lands, and croplands, taking account of atmospheric composition and deposition and fertilizer input. Having high spatial and temporal resolution would be a key feature of the new mapping, and so we try to use new land data for CMIP6. Finally, we discuss how the new emission mapping methodology and regional accounting are likely to make contributions to IPCC and UNFCCC.

  17. Simulating the carbon, water, energy budgets and greenhouse gas emissions of arctic soils with the ISBA land surface model

    Science.gov (United States)

    Morel, Xavier; Decharme, Bertrand; Delire, Christine

    2017-04-01

    Permafrost soils and boreal wetlands represent an important challenge for future climate simulations. Our aim is to be able to correctly represent the most important thermal, hydrologic and carbon cycle related processes in boreal areas with our land surface model ISBA (Masson et al, 2013). This is particularly important since ISBA is part of the CNRM-CM Climate Model (Voldoire et al, 2012), that is used for projections of future climate changes. To achieve this goal, we replaced the one layer original soil carbon module based on the CENTURY model (Parton et al, 1987) by a multi-layer soil carbon module that represents C pools and fluxes (CO2 and CH4), organic matter decomposition, gas diffusion (Khvorostyanov et al., 2008), CH4 ebullition and plant-mediated transport, and cryoturbation (Koven et al., 2009). The carbon budget of the new model is closed. The soil carbon module is tightly coupled to the ISBA energy and water budget module that solves the one-dimensional Fourier law and the mixed-form of the Richards equation explicitly to calculate the time evolution of the soil energy and water budgets (Boone et al., 2000; Decharme et al. 2011). The carbon, energy and water modules are solved using the same vertical discretization. Snowpack processes are represented by a multi-layer snow model (Decharme et al, 2016). We test this new model on a pair of monitoring sites in Greenland, one in a permafrost area (Zackenberg Ecological Research Operations, Jensen et al, 2014) and the other in a region without permafrost (Nuuk Ecological Research Operations, Jensen et al, 2013); both sites are established within the GeoBasis part of the Greenland Ecosystem Monitoring (GEM) program. The site of Chokurdakh, in a permafrost area of Siberia is is our third studied site. We test the model's ability to represent the physical variables (soil temperature and water profiles, snow height), the energy and water fluxes as well as the carbon dioxyde and methane fluxes. We also test the

  18. Estimating methane gas generation from Devil's swamp landfill using greenhouse gas emission models

    Science.gov (United States)

    Adeyemi, Ayodeji Thompson

    Greenhouse gas (GHG) has been a key issue in the study, design, and management of landfills. Landfill gas (LFG) is considered either as a significant source of renewable energy (if extracted and processed accordingly) or significant source of pollution and risk (if not mitigated or processed). A municipal solid waste (MSW) landfill emits a significant amount of methane, a potent GHG. Thus, quantification and mitigation of GHG emissions is an important area of study in engineering and other sciences related to landfill technology and management. The present study will focus on estimating methane generation from Devils swamp landfill (DSLF), a closed landfill in Baton Rouge, LA. The landfill operated for 53 years (1940-1993) and contains both industrial and municipal waste products. Since the Clean Air Act of 1963, landfills are now classified as New Source Performance Standard (NSPS) waste (i.e., waste that will decompose to generate LFG). Currently, the DSLF is being used as source of renewable energy through the "Waste to Energy" program. For this study, to estimate the methane potential in the DSLF, it is important to determine the characteristics and classification of the landfill's wastes. The study uses and compares different GHG modeling tools---LandGEM, a multiphase model, and a simple first-order model---to estimate methane gas emission and compare results with the actual emissions from the DSLF. The sensitivity of the methane generation rate was analyzed by the methane generation models to assess the effects of variables such as initial conditions, specific growth rate, and reaction rate constants. The study concludes that methane (L0) and initial organic concentration in waste (k) are the most important parameters when estimating methane generation using the models.

  19. Robust Modeling of Greenhouse Gas (GHG) Fluxes from Coastal Wetland Ecosystems

    Science.gov (United States)

    Abdul-Aziz, O. I.; Ishtiaq, K. S.

    2014-12-01

    Many critical wetland biogeochemical processes are still largely unknown or poorly understood at best. Yet, available models for predicting wetland greenhouse gas (GHG) fluxes (e.g., CO2, CH4, and N2O) are generally mechanistic in nature. This knowledge gap leads to inappropriate process descriptions or over-parameterizations in existing mechanistic models, which often fail to provide accurate and robust predictions across time and space. We developed a systematic data-analytics and informatics method to identify the dominant controls and quantify the relative linkages of wetland GHG fluxes in relation to various hydro-climatic, sea level, biogeochemical and ecological drivers. The method was applied to data collected from 2012-14 through an extensive field campaign from different blue carbon sites of Waquoit Bay, MA. Multivariate pattern recognition techniques of principal component and factor analyses were employed to identify the dominant controls of wetland GHG fluxes; classifying and grouping process variables based on their similarity and interrelation patterns. Power-law based partial least squares regression models were developed to quantify the relative linkages of major GHGs with different process drivers and stressors, as well as to achieve site-specific predictions of GHG fluxes. Wetland biogeochemical similitude and scaling laws were also investigated to unravel emergent patterns and organizing principles of wetland GHG fluxes. The research findings will guide the development of parsimonious empirical to appropriate mechanistic models for spatio-temporally robust predictions of GHGs fluxes and carbon sequestration from coastal wetland ecosystems. The research is part of two current projects funded by the National Oceanic and Atmospheric Administration and the National Science Foundation; focusing on wetland data collections, knowledge formation, formulation of robust GHGs prediction models, and development of ecological engineering tools.

  20. CNMM: a Catchment Environmental Model for Managing Water Quality and Greenhouse Gas Emissions

    Science.gov (United States)

    Li, Y.

    2015-12-01

    Mitigating agricultural diffuse pollution and greenhouse gas emissions is a complicated task due to tempo-spatial lags between the field practices and the watershed responses. Spatially-distributed modeling is essential to the implementation of cost-effective and best management practices (BMPs) to optimize land uses and nutrient applications as well as to project the impact of climate change on the watershed service functions. CNMM (the Catchment Nutrients Management Model) is a 3D spatially-distributed, grid-based and process-oriented biophysical model comprehensively developed to simulate energy balance, hydrology, plant/crop growth, biogeochemistry of life elements (e.g., C, N and P), waste treatment, waterway vegetation/purification, stream water quality and land management in agricultural watersheds as affected by land utilization strategies such as BMPs and by climate change. The CNMM is driven by a number of spatially-distributed data such as weather, topography (including DEM and shading), stream network, stream water, soil, vegetation and land management (including waste treatments), and runs at an hourly time step. It represents a catchment as a matrix of square uniformly-sized cells, where each cell is defined as a homogeneous hydrological response unit with all the hydrologically-significant parameters the same but varied at soil depths in fine intervals. Therefore, spatial variability is represented by allowing parameters to vary horizontally and vertically in space. A four-direction flux routing algorithm is applied to route water and nutrients across soils of cells governed by the gradients of either water head or elevation. A linear channel reservoir scheme is deployed to route water and nutrients in stream networks. The model is capable of computing CO2, CH4, NH3, NO, N2O and N2 emissions from soils and stream waters. The CNMM can serve as an idea modelling tool to investigate the overwhelming critical zone research at various catchment scales.

  1. An example of fingerprint detection of greenhouse climate changes

    Energy Technology Data Exchange (ETDEWEB)

    Karoly, D.J.; Cohen, J.A. [Monash Univ., Clayton, Victoria (Australia); Meehl, G.A. [National Center for Atmospheric Research, Boulder, CO (United States)] [and others

    1994-07-01

    As an example of the technique of fingerprint detection of greenhouse climate change, a multivariate signal or fingerprint of the enhanced greenhouse effect is defined using the zonal mean atmospheric temperature change as a function of height and latitude between equilibrium climate model simulations with control and doubled CO{sub 2} concentrations. This signal is compared with observed atmospheric temperature variations over the period 1963 to 1988 from radiosonde-based global analyses. There is a signiificant increase of this greenhouse signal in the observational data over this period. These results must be treated with caution. Upper air data are available for a short period only, possibly, to be able to resolve any real greenhouse climate change. The greenhouse fingerprint used in this study may not be unique to the enhanced greenhouse effect and may be due to other forcing mechanisms. However, it is shown that the patterns of atmospheric temperature change associated with uniform global increases of sea surface temperature, with El Nino-Southern Oscillation events and with decreases of stratospheric ozone concentrations individually are different from the greenhouse fingerprint used here. 30 refs., 6 figs., 2 tabs.

  2. Modeling GHG emission and energy consumption in selected greenhouses in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Yousefi, M.; Omid, M.; Rafiee, SH.; Khoshnevisan, B. [Department of Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj (Iran, Islamic Republic of)

    2013-07-01

    It is crucial to determine energy efficiency and environmental effects of greenhouse productions. Such study can be a viable solution in probing challenges and existing defects. The aims of this study were to analyze energy consumption and greenhouse gas (GHG) emissions for pepper production using biological method inside greenhouses which used natural gas (NG) heating system in Esfahan province. Data were collected from 22 greenhouse holders using a face to face questionnaire method, in 2010-2011. Also, functional area was selected 1000 m2. Total energy input, total energy output, energy ratio, energy productivity, specific energy, net energy gain and total GHG emissions were calculated as 297799.9 MJ area-1, 3851.84 MJ area-1, 0.013, 0.016 kg MJ-1, 61.85 MJ kg-1, -293948 MJ area-1 and 14390.85 kg CO2 equivalent area-1, respectively. Result revealed that replacing diesel fuel with NG will not be an effective way of reducing energy consumption for greenhouse production. However, it is crucial to focus on energy management in order to enhance the energy and environmental indices. One way to supply adequate input energy and a reduction in GHG emissions is the utilization of renewable and clean energy sources instead of NG and diesel fuel. Also, it is suggested to adopt solar greenhouses in the region and to supply electricity from non-fossil sources seriously.

  3. Shading screens for the improvement of the night-time climate of unheated greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Montero, J. I.; Munoz, P.; Sanchez-Guerrero, M. C.; Medrano, E.; Piscia, D.; Lorenzo, P.

    2013-05-01

    The objective of this work was to study the effect of shading screens, normally used during the day for cooling purposes, on the night-time climate of unheated greenhouses. For this purpose, first a number of experimental measurements were taken during cold nights to characterise the greenhouse climate both with and without an aluminised external screen. Secondly a Computational Fluid Dynamic (CFD) model of greenhouse was developed. After validation of the model by comparison with experimental data, the model was used to simulate the greenhouse climate for different sky conditions ranging from cloudless to overcast nights. Simulations were performed for a greenhouse with internal and external shading screens and for the same greenhouse without screens. Experimental results showed the positive effect of an external shading screen, whose use increased night-time temperature and reduced the risk of thermal inversion. Its effect was much stronger under clear sky conditions. The CFD model supported this conclusion and provided a detailed explanation of the temperature behaviour of all the greenhouse types considered. CFD simulations proved that an aluminised screen placed inside the greenhouse at gutter height gave the greatest thermal increase. Therefore, external or internal screens can help to increase the sustainability of greenhouse production in areas with mild winter climates by enhancing the use of solar energy stored in the greenhouse soil during the previous day and released at night-time. (Author) 39 refs.

  4. 基于全局变量预测模型的温室环境控制方法%Environment control method in greenhouse based on global variable prediction model

    Institute of Scientific and Technical Information of China (English)

    程曼; 袁洪波; 蔡振江; 王楠

    2013-01-01

      针对传统温室控制系统中存在的控制方案达不到最优化、反应滞后、控制器调节不同步等问题,提出了基于全局变量预测模型的温室环境控制方法。该方法将温室内部温度、湿度、光照等数据,控制器当前状态,温室外部环境的相应数据及当地天气情况进行融合,利用各个全局变量通过数学模型得出温室未来环境状况的短期预测值,通过神经网络实现控制方案,解决了温室控制中的大滞后、大惯性等问题。实验结果证明了该方法的有效性及合理性,并对温室内气候智能控制的发展具有一定的参考价值。%Greenhouse control system needs to control the actuators to make corresponding regulations according to the change of the greenhouse climate. When the temperature is too low, the heating system will be used to heat the greenhouse;when it is too high, the ventilation facility, the sun-shading system, or the spray equipment will be employed to cool the greenhouse and avoid overheat. In most conventional greenhouse control systems, the actuators were individually controlled based on the measured value and the setting value. This kind of control systems were working in passive mode and only made regulations when the greenhouse’s climate changed. It could not predict the future status of the greenhouse and then make regulations in advance. Besides, the actuators were established and set individually and could not work together harmoniously, which resulted in over-regulations and vibrations. Therefore, the control system needs to be developed with more intelligence for the whole system management. In this study, interior and exterior environmental information of the greenhouse, crop growing period and local climate data were integrated by using the global prediction model for the development of an innovative greenhouse control system. Compared to conventional greenhouse control systems, the interior and

  5. Life cycle greenhouse gas emissions of current oil sands technologies: GHOST model development and illustrative application.

    Science.gov (United States)

    Charpentier, Alex D; Kofoworola, Oyeshola; Bergerson, Joule A; MacLean, Heather L

    2011-11-01

    A life cycle-based model, GHOST (GreenHouse gas emissions of current Oil Sands Technologies), which quantifies emissions associated with production of diluted bitumen and synthetic crude oil (SCO) is developed. GHOST has the potential to analyze a large set of process configurations, is based on confidential oil sands project operating data, and reports ranges of resulting emissions, improvements over prior studies, which primarily included a limited set of indirect activities, utilized theoretical design data, and reported point estimates. GHOST is demonstrated through application to a major oil sands process, steam-assisted gravity drainage (SAGD). The variability in potential performance of SAGD technologies results in wide ranges of "well-to-refinery entrance gate" emissions (comprising direct and indirect emissions): 18-41 g CO(2)eq/MJ SCO, 9-18 g CO(2)eq/MJ dilbit, and 13-24 g CO(2)eq/MJ synbit. The primary contributor to SAGD's emissions is the combustion of natural gas to produce process steam, making a project's steam-to-oil ratio the most critical parameter in determining GHG performance. The demonstration (a) illustrates that a broad range of technology options, operating conditions, and resulting emissions exist among current oil sands operations, even when considering a single extraction technology, and (b) provides guidance about the feasibility of lowering SAGD project emissions.

  6. Design of Embedded Wireless Temperature Control System for Agricultural Greenhouse%农业大棚嵌入式无线温控系统设计

    Institute of Scientific and Technical Information of China (English)

    李丽丽; 施伟

    2011-01-01

    In order to dynamically real-time monitor the agricultural greenhouse temperature effectively, it proposed to designing a greenhouse temperature control system based on Zigbee wireless network and Linux embedded operating system. The system designed with C/S structure, was composed of lower computer and upper computer in two parts. The lower computer system including temperature acquisition nodes and aggregation nodes: the temperature acquisition nodes complete function of temperature information collection and wireless data transmission in different locations inside the greenhouse, aggregation nodes in addition to completing the data gathering tasks can turn on the fans or heating systems according to feedback control commands from upper computer. The server-side upper computer system stores and analyzes data, and real-time controls lower computer system according to its analysis results. It had proved in practice that the system can accurately monitor the greenhouse temperature, effectively reduced wiring costs and it is helpful to reduce labor costs and increase crop yields.%为了有效实施农业大棚温度动态实时监控,提出采用Zigbee无线网络和Linux嵌入式操作系统设计大棚温度监控系统.系统采用C/S结构设计,分为下位机和上位机2部分.下位机系统分为温度采集节点和汇聚节点,温度采集节点完成大棚内不同地点的温度信息采集和无线数据传输功能;汇聚节点除了完成数据中继任务外,还可根据上位机反馈的控制指令完成排风扇的打开或电热系统的开启工作;服务器端的上位机系统完成数据的储存和分析,并根据分析结果完成对下位机系统的实时控制.实践证明,该系统可精确监控大棚温度,有效降低布线成本,有助于降低劳动成本和提高农作物产量.

  7. The detection of climate change due to the enhanced greenhouse effect

    Science.gov (United States)

    Schiffer, Robert A.; Unninayar, Sushel

    1991-01-01

    The greenhouse effect is accepted as an undisputed fact from both theoretical and observational considerations. In Earth's atmosphere, the primary greenhouse gas is water vapor. The specific concern today is that increasing concentrations of anthropogenically introduced greenhouse gases will, sooner or later, irreversibly alter the climate of Earth. Detecting climate change has been complicated by uncertainties in historical observations and measurements. Thus, the primary concern for the GEDEX project is how can climate change and enhanced greenhouse effects be unambiguously detected and quantified. Specifically examined are the areas of: Earth surface temperature; the free atmosphere (850 millibars and above); space-based measurements; measurement uncertainties; and modeling the observed temperature record.

  8. 78 FR 5347 - Denial of Reconsideration Petition on Model Year 2012-2016 Light Duty Vehicle Greenhouse Gas...

    Science.gov (United States)

    2013-01-25

    ... ameliorating global climate change. PLF petitioned EPA to reconsider its greenhouse gas standards. Because the... Vehicle Greenhouse Gas Emissions Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Denial... final rules establishing greenhouse gas emissions standards from light duty motor vehicles for...

  9. An updated analysis of the attribution of stratospheric ozone and temperature changes to changes in ozone-depleting substances and well-mixed greenhouse gases

    Directory of Open Access Journals (Sweden)

    A. I. Jonsson

    2009-07-01

    Full Text Available This paper presents an analysis of the attribution of past and future changes in stratospheric ozone and temperature to anthropogenic forcings. Recently, Shepherd and Jonsson (2008 argued that such an analysis needs to account for the ozone-temperature feedback, and that the failure to do so could potentially lead to very large errors. This point was illustrated by analyzing chemistry-climate simulations from the Canadian Middle Atmosphere Model (CMAM and attributing both past and future changes to changes in the abundances of ozone-depleting substances (ODS and well-mixed greenhouse gases. In the current paper, we have expanded the analysis to account for the nonlinear radiative response to changes in CO2. It is shown that over centennial time scales the relationship between CO2 abundance and radiative cooling in the upper stratosphere is significantly nonlinear. Failure to account for this effect in multiple linear regression analysis would lead to misleading results. In our attribution analysis the nonlinearity is taken into account by using CO2 heating rate, rather than CO2 abundance, as the explanatory variable. In addition, an error in the way the CO2 forcing changes are implemented in the CMAM has been corrected, which significantly affects the results for the recent past. As the radiation scheme, based on Fomichev et al. (1998, is used in several other models we provide some description of the problem and how it was fixed.

    The updated results are as follows. From 1975–1995, during the period of rapid ozone decline, ODS and CO2 increases contributed roughly equally to upper stratospheric cooling, while the CO2-induced cooling (which increases ozone masked about 20% of the ODS-induced ozone depletion. From 2010–2040, during the period of most rapid ozone recovery, CO2-induced cooling will dominate the upper stratospheric temperature trend

  10. A world ocean model for greenhouse sensitivity studies: Resolution intercomparison and the role of diagnostic forcing

    Energy Technology Data Exchange (ETDEWEB)

    Washington, W.M.; Meehl, G.A.; VerPlank, L.; Bettge, T.W. [National Center for Atmospheric Research, Boulder, CO (United States)

    1994-05-01

    This article documents the simulation capability of this improved 1{degrees} global ocean model, shows improvements over our earlier 5{degrees} version, and compares it to features simulated with a 0.5{degrees} model. These experiments use a model spin-up methodology whereby the ocean model can subsequently be coupled to an atmospheric model and used for order 100-year coupled model integrations. With present-day computers, 1{degrees} is a reasonable compromise in resolution that allows for century-long coupled experiments. The 1{degrees} ocean model is derived from a 0.5{degrees}-resolution model developed for studies of the global eddy-resolving world ocean circulation. The 0.5{degrees} bottom topography and continental outlines have been altered to be compatible with the 1{degrees} resolution and the Arctic Ocean has been added. Results show a dramatic intensification of the meridional overturning circulation (order of magnitude) with perpetual winter surface temperature forcing in the North Atlantic and strong intensification (factor of three) with perpetual early winter temperatures in that region. These effects are felt throughout the Atlantic (particularly an intensified and northward-shifted Gulf Stream outflow). In the Pacific, the temperature gradient strengthens in the thermocline, thus helping counter the systematic error of a thermocline that is too diffuse. 41 refs., 13 figs.

  11. Conceptual model for calculation of greenhouse gas emissions from deforestation in the Brazilian Caatinga

    Science.gov (United States)

    Sousa Neto, E. R.; Ometto, J. P.

    2012-12-01

    The process of removing a forest to open new agricultural lands, which has been very intensive in developing countries like Brazil during the last decades, contributes to about 12% of the global anthropogenic emissions (Le Quéré et al., 2009). Forest cover removal releases carbon and other greenhouse gases like methane (CH4) and nitrous oxide (N2O), as a result of burning trees, followed by gradual decomposition of the forest biomass left on the ground while pasture or crop plantations are being established (Ramankutty et al., 2007). In Brazil, the 2nd Brazilian National Communication to the United Nations Framework Convention on Climate Change (UNFCCC), presents the mean annual net CO2 emissions caused by changes in land use in each Brazilian biome and the first place in the ranking is occupied by the Amazon Rainforest Biome (860,874 Gg), followed by Savannah (302,715 Gg), Atlantic Forest (79,109 Gg), Caatinga (37,628 Gg), Pantanal (16,172 Gg) and Pampa (-102 Gg) (MCT 2010). The estimates of CO2 emissions caused by land use changes in the Brazilian semiarid region (Caatinga) are very limited and scarce, and associated to uncertainties which are directly related to the estimated biomass in different types of vegetation which are spatially distributed within the biome, as well as the correct representation of the dynamics of the deforestation process itself, and the more accurate mapping use and land cover. This project aims to estimate carbon emissions from land use changes in Pernambuco State, Brazil, by using the INPE-EM model. The model will incorporate the temporal dynamics related to the deforestation process, and accounts for the biophysical and socioeconomic heterogeneity of the region in study

  12. A world ocean model for greenhouse sensitivity studies: resolution intercomparison and the role of diagnostic forcing

    Science.gov (United States)

    Washington, Warren M.; Meehl, Gerald A.; Verplank, Lynda; Bettge, Thomas W.

    1994-05-01

    We have developed an improved version of a world ocean model with the intention of coupling to an atmospheric model. This article documents the simulation capability of this 1° global ocean model, shows improvements over our earlier 5° version, and compares it to features simulated with a 0.5° model. These experiments use a model spin-up methodology whereby the ocean model can subsequently be coupled to an atmospheric model and used for order 100-year coupled model integrations. With present-day computers, 1° is a reasonable compromise in resolution that allows for century-long coupled experiments. The 1° ocean model is derived from a 0.5°-resolution model developed by A. Semtner (Naval Postgraduate School) and R. Chervin (National Center for Atmospheric Research) for studies of the global eddy-resolving world ocean circulation. The 0.5° bottom topography and continental outlines have been altered to be compatible with the 1° resolution, and the Arctic Ocean has been added. We describe the ocean simulation characteristics of the 1° version and compare the result of weakly constraining (three-year time scale) the three-dimensional temperature and salinity fields to the observations below the thermocline (710 m) with the model forced only at the top of the ocean by observed annual mean wind stress, temperature, and salinity. The 1° simulations indicate that major ocean circulation patterns are greatly improved compared to the 5° version and are qualitatively reproduced in comparison to the 0.5° version. Using the annual mean top forcing alone in a 100-year simulation with the 1° version preserves the general features of the major observed temperature and salinity structure with most climate drift occurring mainly beneath the thermocline in the first 50 75 years. Because the thermohaline circulation in the 1° version is relatively weak with annual mean forcing, we demonstrate the importance of the seasonal cycle by performing two sensitivity experiments

  13. Sorghum production under future climate in the Southwestern USA: model projections of yield, greenhouse gas emissions and soil C fluxes

    Science.gov (United States)

    Duval, B.; Ghimire, R.; Hartman, M. D.; Marsalis, M.

    2016-12-01

    Large tracts of semi-arid land in the Southwestern USA are relatively less important for food production than the US Corn Belt, and represent a promising area for expansion of biofuel/bioproduct crops. However, high temperatures, low available water and high solar radiation in the SW represent a challenge to suitable feedstock development, and future climate change scenarios predict that portions of the SW will experience increased temperature and temporal shifts in precipitation distribution. Sorghum (Sorghum bicolor) is a valuable forage crop with promise as a biofuel feedstock, given its high biomass under semi-arid conditions, relatively lower N fertilizer requirements compared to corn, and salinity tolerance. To evaluate the environmental impact of expanded sorghum cultivation under future climate in the SW USA, we used the DayCent model in concert with a suite of downscaled future weather projections to predict biogeochemical consequences (greenhouse gas flux and impacts on soil carbon) of sorghum cultivation in New Mexico. The model showed good correspondence with yield data from field trials including both dryland and irrigated sorghum (measured vs. modeled; r2 = 0.75). Simulation experiments tested the effect of dryland production versus irrigation, low N versus high N inputs and delayed fertilizer application. Nitrogen application timing and irrigation impacted yield and N2O emissions less than N rate and climate. Across N and irrigation treatments, future climate simulations resulted in 6% increased yield and 20% lower N2O emissions compared to current climate. Soil C pools declined under future climate. The greatest declines in soil C were from low N input sorghum simulations, regardless of irrigation (>20% declines in SOM in both cases), and requires further evaluation to determine if changing future climate is driving these declines, or if they are a function of prolonged sorghum-fallow rotations in the model. The relatively small gain in yield for

  14. Atmospheric greenhouse gases retrieved from SCIAMACHY: comparison to ground-based FTS measurements and model results

    Directory of Open Access Journals (Sweden)

    O. Schneising

    2012-02-01

    Full Text Available SCIAMACHY onboard ENVISAT (launched in 2002 enables the retrieval of global long-term column-averaged dry air mole fractions of the two most important anthropogenic greenhouse gases carbon dioxide and methane (denoted XCO2 and XCH4. In order to assess the quality of the greenhouse gas data obtained with the recently introduced v2 of the scientific retrieval algorithm WFM-DOAS, we present validations with ground-based Fourier Transform Spectrometer (FTS measurements and comparisons with model results at eight Total Carbon Column Observing Network (TCCON sites providing realistic error estimates of the satellite data. Such validation is a prerequisite to assess the suitability of data sets for their use in inverse modelling.

    It is shown that there are generally no significant differences between the carbon dioxide annual increases of SCIAMACHY and the assimilation system CarbonTracker (2.00 ± 0.16 ppm yr−1 compared to 1.94 ± 0.03 ppm yr−1 on global average. The XCO2 seasonal cycle amplitudes derived from SCIAMACHY are typically larger than those from TCCON which are in turn larger than those from CarbonTracker. The absolute values of the northern hemispheric TCCON seasonal cycle amplitudes are closer to SCIAMACHY than to CarbonTracker and the corresponding differences are not significant when compared with SCIAMACHY, whereas they can be significant for a subset of the analysed TCCON sites when compared with CarbonTracker. At Darwin we find discrepancies of the seasonal cycle derived from SCIAMACHY compared to the other data sets which can probably be ascribed to occurrences of undetected thin clouds. Based on the comparison with the reference data, we conclude that the carbon dioxide data set can be characterised by a regional relative precision (mean standard deviation of the differences of about 2.2 ppm and a relative accuracy (standard deviation of the mean differences

  15. Temperature/flow field simulation and parameter optimal design for greenhouses with fan-pad evaporative cooling system%湿帘-风机降温下的温室热/流场模拟及降温系统参数优化

    Institute of Scientific and Technical Information of China (English)

    胥芳; 蔡彦文; 陈教料; 张立彬

    2015-01-01

    was developed to simulate the microclimate distribution and air circulation inside the greenhouse adopting fan-pad cooling system. The verification experiment was conducted in a Venlo-type greenhouse in the campus of Zhejiang University of Technology (30°14′N, 120°09′E) from 12:30 to 13:30 on July 23, 2012. Thirteen observation points of T1-T10 and TH1-TH3 were set up in the experimental greenhouse to validate the simulated air temperature and velocity. The errors between simulated and measured air temperature at the observation points varied from 0.7 to 2℃, and the errors of air velocity were less than 0.13 m/s. Compared with the measured values, the absolute mean errors of simulated temperature and air velocity were less than 4% and 6% respectively. It proved that the CFD method is reliable to estimate the distribution of air velocity and temperature in the greenhouse. The validated CFD model was then used to further analyze the cooling performance of different greenhouse cases in terms of the greenhouse lengths, the evaporative pad areas and the greenhouse ventilation rates. The indoor environment with the temperature of below 30℃ and the velocity of below 1 m/s was suitable for crop growth, and this condition was used as a criterion for optimal design. Based on the orthogonal test method, greenhouse cases with different greenhouse lengths, evaporative pad areas and air velocities of fans were classified and simulated to analyze their relations. The simulations illustrated that the greenhouse ventilation rate of 153.1 m3/(m2·h) and the minimum pad area of 6 m2can meet the cooling requirement in a Venlo-type greenhouse with 24 m length and 9.6 m width. In contrast with greenhouse of 70 m length, the maximum pad area of 13.5 m2had to be configured, because the greenhouse with smaller evaporative pad need combine with the fan’s velocity of more than 105 m3/(m2·h). According to the relations among greenhouse length, evaporative pad area and fan

  16. Correlation Models for Temperature Fields

    KAUST Repository

    North, Gerald R.

    2011-05-16

    This paper presents derivations of some analytical forms for spatial correlations of evolving random fields governed by a white-noise-driven damped diffusion equation that is the analog of autoregressive order 1 in time and autoregressive order 2 in space. The study considers the two-dimensional plane and the surface of a sphere, both of which have been studied before, but here time is introduced to the problem. Such models have a finite characteristic length (roughly the separation at which the autocorrelation falls to 1/e) and a relaxation time scale. In particular, the characteristic length of a particular temporal Fourier component of the field increases to a finite value as the frequency of the particular component decreases. Some near-analytical formulas are provided for the results. A potential application is to the correlation structure of surface temperature fields and to the estimation of large area averages, depending on how the original datastream is filtered into a distribution of Fourier frequencies (e.g., moving average, low pass, or narrow band). The form of the governing equation is just that of the simple energy balance climate models, which have a long history in climate studies. The physical motivation provided by the derivation from a climate model provides some heuristic appeal to the approach and suggests extensions of the work to nonuniform cases.

  17. Modelling and remote sensing of canopy light interception and plant stress in greenhouses

    NARCIS (Netherlands)

    Sarlikioti, V.

    2011-01-01

    A greenhouse crop can be approached as an open system that can be affected by a number of parameters such as light, climate or nutrient supply. In the last decades efforts have been made to understand the functioning of this system and the interaction between the different parameters. The intensive

  18. Modelling and remote sensing of canopy light interception and plant stress in greenhouses

    NARCIS (Netherlands)

    Sarlikioti, V.

    2011-01-01

    A greenhouse crop can be approached as an open system that can be affected by a number of parameters such as light, climate or nutrient supply. In the last decades efforts have been made to understand the functioning of this system and the interaction between the different parameters. The intensive

  19. Efficient cooling of strawberries: From model calculation to implementation in a commercial greenhouse

    NARCIS (Netherlands)

    Kempkes, F.L.K.; Maaswinkel, R.H.M.; Verkerke, W.

    2012-01-01

    Growing strawberries in autumn and spring crop cycle in greenhouses requires a start in the first week of August. Light intensity in this period ensures a good quality of crop with enough flower capacity for the spring crop cycle. A disadvantage of this early start is the almost non controllability

  20. Last interglacial temperature evolution – a model inter-comparison

    Directory of Open Access Journals (Sweden)

    H. Renssen

    2012-09-01

    Full Text Available There is a growing number of proxy-based reconstructions detailing the climatic changes during the Last Interglacial period. This period is of special interest because large parts of the globe were characterized by a warmer-than-present-day climate, making this period an interesting test bed for climate models in the light of projected global warming. However, mainly because synchronizing the different records is difficult, there is no consensus on a global picture of Last Interglacial temperature changes. Here we present the first model inter-comparison of transient simulations covering the Last Interglacial period. By comparing the different simulations we aim at investigating the robustness of the simulated surface air temperature evolution. The model inter-comparison shows a robust Northern Hemisphere July temperature evolution characterized by a maximum between 130–122 ka BP with temperatures 0.4 to 6.8 K above pre-industrial values. This temperature evolution is in line with the changes in June insolation and greenhouse-gas concentrations. For the evolution of July temperatures in the Southern Hemisphere, the picture emerging from the inter-comparison is less clear. However, it does show that including greenhouse-gas concentration changes is critical. The simulations that include this forcing show an early, 128 ka BP July temperature anomaly maximum of 0.5 to 2.6 K. The robustness of simulated January temperatures is large in the Southern Hemisphere and the mid-latitudes of the Northern Hemisphere. In these latitudes maximum January temperature anomalies of respectively −2.5 to 2 K and 0 to 2 K are simulated for the period after 118 ka BP. The inter-comparison is inconclusive on the evolution of January temperatures in the high-latitudes of the Northern Hemisphere. Further investigation of regional anomalous patterns and inter-model differences indicate that in specific regions, feedbacks within the climate system are important for the

  1. Empirical Quantification of the Runaway Greenhouse Limit on Earth

    Science.gov (United States)

    Goldblatt, C.; Dewey, M. C.

    2015-12-01

    There have been many modeling studies of the runaway greenhouse effect and the conditions required to produce one on an Earth-like planet, however these models have not been verified with empirical evidence. It has been suggested that the Earth's tropics may be near a state of localized runaway greenhouse, meaning the surface temperature and atmospheric composition in those areas could cause runaway greenhouse, were it not for the tempering effects of meridional heat transport and circulation (Pierrehumbert, 1995). Using the assumption that some areas of the Earth's tropics may be under these conditions, this study uses measurements of the atmospheric properties, surface properties, and radiation budgets of these areas to quantify a radiation limit for runaway greenhouse on Earth, by analyzing the dependence of outgoing longwave radiation (OLR) at the top of the atmosphere on surface temperature and total column water vapour. An upper limit on OLR for clear-sky conditions was found between 289.8 W/m2 and 292.2 W/m2, which occurred at surface temperatures near 300K. For surface temperatures above this threshold, total column water vapour increased, but OLR initially decreased and then remained relatively constant, between 273.6 W/m2 and 279.7 W/m2. These limits are in good agreement with recent modeling results (Goldblatt et al., 2013), supporting the idea that some of the Earth's tropics may be in localized runaway greenhouse, and that radiation limits for runaway greenhouse on Earth can be empirically derived. This research was done as part of Maura Dewey's undergraduate honours thesis at the University of Victoria. Refs: Robert T. Pierrehumbert. Thermostats, radiator fins, and the local runaway greenhouse. Journal of Atmospheric Sciences, 52(10):1784-1806, 1995. Colin Goldblatt, Tyler D. Robinson, Kevin J. Zahnle, and David Crisp. Low simulated radiation limit for runaway greenhouse climates. Nature Geoscience, 6:661-667, 2013.

  2. 面向控制的温室系统小气候环境模型要求与现状%Requirement and current situation of control-oriented microclimate environmental model in greenhouse system

    Institute of Scientific and Technical Information of China (English)

    徐立鸿; 苏远平; 梁毓明

    2013-01-01

    ; while in the latter, environmental states are tuned to track those obtained trajectories. Based on this framework, some relevant models to the greenhouse system, such as greenhouse microclimate model, crop growth and yield model, energy consumption predicting model and CO2 consumption predicting model, need to be built, and some constraints over environmental states and control inputs must be determined. However, most greenhouse climate models and crop growth models proposed in literature are research-oriented rather than based on practical cultivation. The biggest difference between the two is that research-oriented models solely focus on the optimal set-points of internal climatic parameters for maximum crop yield, ignoring the abilities of control actuators, the ambient climate change, and the overall energy consumption. From a practical point of view, the latters are certainly necessary in greenhouse models. It would be difficult to achieve realistic results if the models are incomplete. The lack of reliable greenhouse models has become the greatest difficulty for greenhouse optimization and control. In this paper, the latest trends in greenhouse climate models, crops growth models, energy consumption models, and CO2 consumption models are reviewed in details. The main shortcomings of current models can be summarized as follows:(1) although some models obtained by ample mechanisms, their structures are excessively complicated, such that the corresponding computations are very expensive, which makes it difficult to design an efficient controller based on them. This class of models interprets the real physical laws with large number of parameters and complex structures, and Vanthoor’s model and TOMGRO are examples; (2) some models are too simple to accurately reflect the relationships between greenhouse environment and crop growth. Generally, only the dynamics of air temperature and humidity in greenhouses are described in this class of greenhouse climate model

  3. A greenhouse gas monitoring and modelling system for Switzerland: The CarboCount CH project

    Science.gov (United States)

    Brunner, Dominik; Buchmann, Nina; Eugster, Werner; Seneviratne, Sonia; Davin, Edouard; Gruber, Nicolas; Leuenberger, Markus; Bey, Isabelle; Bamberger, Ines; Henne, Stephan; Liu, Yu; Mystakidis, Stefanos; Oney, Brian; Roches, Anne

    2014-05-01

    CarboCount CH is a collaborative project of six research institutes in Switzerland. It investigates human-related emissions and natural exchange between the atmosphere and the biosphere of the two most important long-lived greenhouse gases carbon dioxide (CO2) and methane (CH4) at the regional scale with a special focus on Switzerland. For this purpose, four new measurement sites have been established including a 210 m tall tower at Beromünster, a water reservoir tower in flat terrain at Gimmiz, and two mountain sites at Lägern (856 m a.s.l.) and Früebüel (977 m a.s.l.). All sites were equipped with high-precision instruments for continuous measurements of CO2, CH4, and partially CO. The continuous CO measurements as well as bi-weekly 14CO2 samples at the tall tower site help to distinguish between anthropogenic and biogenic contributions to the observed CO2 concentrations. All data are transferred to the central processing facility at Empa where the calibrated data are uploaded to a database and made remotely accessible to all partners. The network is complemented by flux measurements of the Swiss Fluxnet network and other existing sites with CO2 and/or CH4 measurements including the high altitude GAW site Jungfraujoch. The four CarboCount CH sites have been operating reliably and almost continuously for more than one year now. For data interpretation and top-down flux estimation, two separate atmospheric transport and inverse modeling systems are being developed within the project. The first one uses the new tracer transport module of the regional numerical weather prediction model COSMO together with an Ensemble Kalman filter scheme. The second framework is based on backward simulations with the Lagrangian transport model FLEXPART-COSMO. Anthropogenic a priori emissions are obtained from newly developed high-resolution (500 m x 500 m) inventories of diurnally and seasonally varying CO2 and CH4 emissions in Switzerland, merged with European and global

  4. Applications of an Energy Transfer Model to Three Problems in Planetary Regoliths: The Solid-State Greenhouse, Thermal Beaming, and Emittance Spectra

    Science.gov (United States)

    Hapke, Bruce

    1996-01-01

    Several problems of interest in planetary infrared remote sensing are investigated using a new radiative-conductive model of energy transfer in regoliths: the solid-state greenhouse effect, thermal beaming, and reststrahlen spectra. The results of the analysis are as follows: (1) The solid-state greenhouse effect is self-limiting to a rise of a few tens of degrees in bodies of the outer solar system. (2) Non-Lambertian directional emissivity can account for only about 20% of the observed thermal beaming factor. The remainder must have another cause, presumably surface roughness effects. (3) The maximum in a reststrahlen emissivity spectrum does not occur exactly at the Christiansen wavelength where, by definition, the real part of the refractive index equals one, but rather at the first transition minimum in reflectance associated with the transition from particle scattering being dominated by volume scattering to that dominated by strong surface scattering. The transparency feature is at the second transition minimum and does not require the presence of a second band at longer wavelength for its occurance. Subsurface temperature gradients have only a small effect on emissivity bands.

  5. On the Modeling and Emulation of the Microclimate of Sunlight Greenhouse in the Northwest China%西北日光温室小气候建模与仿真

    Institute of Scientific and Technical Information of China (English)

    田亚立; 杨泽林; 李相白

    2011-01-01

    The microclimate of greenhouse was a nonstationary, nonliner dynamic environment with strong coupling and great lag. The model and emulation were established for the greenhouse microclimate in order to build a sound supervisory and control system of the greenhouse. Based on the characteristics of microclimate of greenhouse, and the specific macroclimate in the summer of northwest china, the temperature and humidity models were set up by the new international method of heat banlance steady state equation. Through the analysis and emulation experiments, the effects were basically conform what were supposed.%针对温室小气候的基本特点,结合国际较新的热平衡稳定状态方法,根据西北地区夏季的温室具体情况,建立了温室的温度、湿度模型.通过对模型的分析和仿真试验,取得了较好的效果.

  6. Pilot Greenhouse

    CERN Multimedia

    1983-01-01

    This pilot greenhouse was built in collaboration with the "Association des Maraichers" of Geneva in the frame of the study for making use of the heat rejected as warm water by CERN accelerators and experiments. Among other improvements, more automated and precise regulation systems for heating and ventilation were developed. See also 8305598X.

  7. The Greenhouse Effect and Built Environment Education.

    Science.gov (United States)

    Greenall Gough, Annette; Gough, Noel

    The greenhouse effect has always existed. Without the greenhouse effect, Earth could well have the oven-like environment of Venus or the deep-freeze environment of Mars. There is some debate about how much the Earth's surface temperature will rise given a certain amount of increase in the amount of greenhouse gases such as carbon dioxide, nitrous…

  8. 沿海不同棚架构型温度变化规律及西瓜种植研究%Temperature Change Rules of Different Steel Greenhouses and Their Effects on Watermelon Cultivation

    Institute of Scientific and Technical Information of China (English)

    孙兴祥; 林红梅

    2013-01-01

    In the paper, we studied the temperature change rules of different types of steel greenhouses and their effects on the growth and development of watermelon. The results showed that, as the greenhouse depth-width ratio became larger, the atmospheric temperature in the greenhouses increased and reduced quicker, and the difference of the day and night earth temperature became larger, indicating their better maintaining effects on atmospheric temperature but worse maintaining effects on earth temperature. In the watermelon cultivation in coastal areas of Jiangsu, the greenhouse A4 possessed the best temperature maintaining effects and comprehensive evaluation, and the structure of greenhouse A4 was as follows:the centre-height of the outer steel greenhouse, inner steel greenhouse and small arch shed were 2.5 m, 2.4 m and 0.8 m, with their width were 7.0 m, 6.6 m and 2.0 m, respectively. The greenhouse A1 was more affordable, and its structure was as follows:the centre-height of the outer steel greenhouse, inner steel greenhouse and small arch shed were 1.8 m, 1.7 m and 0.8 m, with their width were 5.0 m, 4.6 m and 2.0 m, respectively.%  研究了不同棚型内的温度变化,以及其对西瓜生长和发育的影响.研究结果表明,棚高宽比大,棚内气温升高快,降低也快,日夜气温温差大,日夜地温温差大,气温保温性差,但地温保温性好;沿海地区大棚西瓜种植采用A4型棚(外棚顶高2.5 m、宽7.0 m,内棚顶高2.4 m、宽6.6 m,小棚顶高0.8 m、宽2.0 m)效果好,采用A1型棚(外棚顶高1.8 m、宽5.0 m,内棚顶高1.7 m、宽4.6 m,小棚顶高0.8 m、宽2.0 m)较为经济.

  9. Analytical modelling of temperature effects on synapses

    CERN Document Server

    Kufel, Dominik S

    2016-01-01

    It was previously reported, that temperature may significantly influence neural dynamics on different levels of brain modelling. Due to this fact, while creating the model in computational neuroscience we would like to make it scalable for wide-range of various brain temperatures. However currently, because of a lack of experimental data and an absence of analytical model describing temperature influence on synapses, it is not possible to include temperature effects on multi-neuron modelling level. In this paper, we propose first step to deal with this problem: new analytical model of AMPA-type synaptic conductance, which is able to include temperature effects in low-frequency stimulations. It was constructed on basis of Markov model description of AMPA receptor kinetics and few simplifications motivated both experimentally and from Monte Carlo simulation of synaptic transmission. The model may be used for efficient and accurate implementation of temperature effects on AMPA receptor conductance in large scale...

  10. Advances in Researches of Low Temperature and Cold Damage Prevention Technology in Sunlight Greenhouse%日光温室低温冷冻害防御技术研究进展

    Institute of Scientific and Technical Information of China (English)

    董思瑶; 王海荣

    2015-01-01

    Low temperature and cold damage prevention is an important subject for the safe production of sunlight green-house. The advances in the researches on the causes of low temperature and cold damage in the sunlight greenhouse as well as the technology for preventing it are discussed. The technology of increasing temperature automatically in the Internet of Things-based sunlight greenhouse is put forward to provide a basis for further research.%低温冷害、冻害防御是日光温室安全生产的重要课题.通过对日光温室低温冷、冻害成因及防御技术的进展研究,提出基于物联网的日光温室自动补温技术,为进一步研究提供基础.

  11. Modelling and evaluation of productivity and economic feasibility of a combined production of tomato and algae in Dutch greenhouses

    NARCIS (Netherlands)

    Slager, B.; Sapounas, A.; Henten, van E.J.; Hemming, S.

    2014-01-01

    Combination of production of algae and tomato increases efficient use of available resources of greenhouse enterprises, such as controlled environment, water and nutrients, carbon dioxide, greenhouse space and infrastructure and knowledge. No information is available, however, about the potential

  12. Prediction Model of Greenhouse Eggplant Transpiration Rate Based on BP Neural Network%基于BP-NN的温室膜下滴灌茄子蒸腾速率预测模型

    Institute of Scientific and Technical Information of China (English)

    葛建坤; 李小平; 罗金耀

    2016-01-01

    通过田间试验,对温室膜下滴灌茄子冠层叶片蒸腾速率的变化规律进行了深入研究。通过分析温室内地面温度、相对湿度、植株冠层温度、气压、水面蒸发、太阳辐射等6个环境参数与茄子蒸腾速率的综合影响关系,确定了网络拓扑结构为6-9-1。并应用 MATLAB 软件,选择 Levenberg-Marquardt (L-M)优化算法,建立了基于 Back Propagation(BP)神经网络的温室膜下滴灌茄子蒸腾速率预测模型。经模型验证得出,BP 神经网络模型预测值与蒸腾速率实测值间拟合效果较好,平均相对误差为0.0298,达到预测精度要求。该研究成果对温室膜下滴灌作物需水规律及需水量研究具有较好的参考价值。%In order to reveal the law of crop transpiration in greenhouse,a field experiment on transpiration rate of greenhouse egg-plant with drip irrigation under mulch was taken in a Venlo type greenhouse in North China University of Water Resources and Elec-tric Power.Through the analysis on the combined influence between eggplant transpiration rate and 6 indoor environmental factors (greenhouse ground temperature,relative humidity,plant canopy temperature,air pressure,evaporation and solar radiation),topol-ogical structure of the model was discussed and determined (6-9-1).And a prediction model of greenhouse eggplant transpiration rate was established based on BP Neural network of L-M optimizing algorithm,by using MATLAB.After the model validation,the re-sults indicated that,the BP neural network prediction model has a high precision,the predicted value fits the measured value well, and average relative error is only 0.0298,which meets the precision requirement.The research result has a certain reference value to the study on crop water requirement in greenhouse with drip irrigation under mulch.

  13. Modeling the transfer of arsenic from soil to carrot (Daucus carota L.)--a greenhouse and field-based study.

    Science.gov (United States)

    Ding, Changfeng; Zhou, Fen; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

    2015-07-01

    Reliable empirical models describing arsenic (As) transfer in soil-plant systems are needed to estimate the human As burden from dietary intake. A greenhouse experiment was conducted in parallel with a field trial located at three sites through China to develop and validate soil-plant transfer models to predict As concentrations in carrot (Daucus carota L.). Stepwise multiple linear regression relationships were based on soil properties and the pseudo total (aqua regia) or available (0.5 M NaHCO3) soil As fractions. Carrot As contents were best predicted by the pseudo total soil As concentrations in combination with soil pH and Fe oxide, with the percentage of variation explained being up to 70 %. The constructed prediction model was further validated and improved to avoid overprotection using data from the field trial. The final obtained model is of great practical relevance to the prediction of As uptake under field conditions.

  14. A model for the data extrapolation of greenhouse gas emissions in the Brazilian hydroelectric system

    Science.gov (United States)

    Pinguelli Rosa, Luiz; Aurélio dos Santos, Marco; Gesteira, Claudio; Elias Xavier, Adilson

    2016-06-01

    Hydropower reservoirs are artificial water systems and comprise a small proportion of the Earth’s continental territory. However, they play an important role in the aquatic biogeochemistry and may affect the environment negatively. Since the 90s, as a result of research on organic matter decay in manmade flooded areas, some reports have associated greenhouse gas emissions with dam construction. Pioneering work carried out in the early period challenged the view that hydroelectric plants generate completely clean energy. Those estimates suggested that GHG emissions into the atmosphere from some hydroelectric dams may be significant when measured per unit of energy generated and should be compared to GHG emissions from fossil fuels used for power generation. The contribution to global warming of greenhouse gases emitted by hydropower reservoirs is currently the subject of various international discussions and debates. One of the most controversial issues is the extrapolation of data from different sites. In this study, the extrapolation from a site sample where measurements were made to the complete set of 251 reservoirs in Brazil, comprising a total flooded area of 32 485 square kilometers, was derived from the theory of self-organized criticality. We employed a power law for its statistical representation. The present article reviews the data generated at that time in order to demonstrate how, with the help of mathematical tools, we can extrapolate values from one reservoir to another without compromising the reliability of the results.

  15. Temperature dependent extension of a hysteresis model

    OpenAIRE

    Sixdenier, Fabien; MESSAL, Oualid; Hilal, Alaa; Martin, Christian; Raulet, Marie-Ange

    2015-01-01

    International audience; Some soft magnetic materials (like ferrites but not only) are strongly dependent of the temperature. In order to predict their behaviour in electrical devices, engineers need hysteresis models able to take into account the temperature. This paper is an attempt to take into account the temperature in an existing model of hysteresis through its parameters. Variations of some parameters are issued from Weiss’s works and others have to be fitted numerically. Simulation res...

  16. Testing the Early Mars H2-CO2 Greenhouse Hypothesis with a 1-D Photochemical Model

    CERN Document Server

    Batalha, Natasha; Ramirez, Ramses; Kasting, James

    2015-01-01

    A recent study by Ramirez et al. (2014) demonstrated that an atmosphere with 1.3-4 bar of CO2 and H2O, in addition to 5-20% H2, could have raised the mean annual and global surface temperature of early Mars above the freezing point of water. Such warm temperatures appear necessary to generate the rainfall (or snowfall) amounts required to carve the ancient martian valleys. Here, we use our best estimates for early martian outgassing rates, along with a 1-D photochemical model, to assess the conversion efficiency of CO, CH4, and H2S to CO2, SO2, and H2. Our outgassing estimates assume that Mars was actively recycling volatiles between its crust and interior, as Earth does today. H2 production from serpentinization and deposition of banded iron-formations is also considered. Under these assumptions, maintaining an H2 concentration of ~1-2% by volume is achievable, but reaching 5% H2 requires additional H2 sources or a slowing of the hydrogen escape rate below the diffusion limit. If the early martian atmosphere...

  17. Modeling and numerical simulation of greenhouse gas emissions from a stationary Diesel engine operating with ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Bergel, Andre; Viana, Sarah de Resende; Martins, Cristiane Aparecida [Instituto Tecnologica da Aeronautica - ITA, Sao Jose dos Campos, SP (Brazil)], e-mail: cmartins@ita.br; Souza, Francisco Jose de [Universidade Federal de Uberlandia (UFU), MG (Brazil)], e-mail: fjsouza@mecanica.ufu.br

    2010-07-01

    The present work aims at modeling and simulating a stationary, compression ignition motor, operating with ethanol at different levels of EGR. The objective is to quantify the influence of these parameters in the atmospheric pollutant emissions (CO, NO{sub X} and Particulate Matter). Specifications of a diesel engine were used, with compression ratio 19:1, operating with ethanol with a percentile of EGR of 0, 10, 20 and 30%. In the simulation, the combustion model, ECFM-3Z, and the turbulence model k-{zeta}-f were used, besides conditions for the temperatures of the combustion chamber, piston, cylinder head and glow plug. The spray characterization was done through the calculation of the injected fuel mass and parameters like spray angle, droplet size, number of holes, position of the injector and others. For the reduction of the simulation time, the crank angle range of is only 130[CAD], beginning at 30 deg BTDC and concluding at 100 deg ATDC. The assessment of the influence of the different EGR concentrations felt for the analysis of pollutant contained in the end of simulation. A very small delay in the ignition of the fuel injected and the emission of a minor amount of nitrogen oxides were observed in all cases as the EGR level used was increased. (author)

  18. Development of TGS2611 methane sensor and SHT11 humidity and temperature sensor for measuring greenhouse gas on peatlands in south kalimantan, indonesia

    Science.gov (United States)

    Sugriwan, I.; Soesanto, O.

    2017-05-01

    The research was focused on development of data acquisition system to monitor the content of methane, relative humidity and temperature on peatlands in South Kalimantan, Indonesia. Methane is one of greenhouse gases that emitted from peatlands; while humidity and temperature are important parameters of microclimate on peatlands. The content of methane, humidity and temperature are three parameters were monitored digitally, real time, continuously and automatically record by data acquisition systems that interfaced to the personal computer. The hardware of data acquisition system consists of power supply unit, TGS2611 methane gas sensor, SHT11 humidity and temperature sensors, voltage follower, ATMega8535 microcontroller, 16 × 2 LCD character and personal computer. ATMega8535 module is a device to manage all part in measuring instrument. The software which is responsible to take sensor data, calculate characteristic equation and send data to 16 × 2 LCD character are Basic Compiler. To interface between measuring instrument and personal computer is maintained by Delphi 7. The result of data acquisition showed on 16 × 2 LCD characters, PC monitor and database with developed by XAMPP. Methane, humidity, and temperature which release from peatlands are trapped by Closed-Chamber Measurement with dimension 60 × 50 × 40 cm3. TGS2611 methane gas sensor and SHT11 humidity and temperature sensor are calibrated to determine transfer function used to data communication between sensors and microcontroller and integrated into ATMega8535 Microcontroller. Calculation of RS and RL of TGS2611 methane gas sensor refer to data sheet and obtained respectively 1360 ohm and 905 ohm. The characteristic equation of TGS2611 satisfies equation VRL = 0.561 ln n - 2.2641 volt, with n is a various concentrations and VRL in volt. The microcontroller maintained the voltage signal than interfaced it to liquid crystal displays and personal computer (laptop) to display result of the measurement

  19. The role of atmospheric greenhouse gases, orbital parameters, and southern ocean gateways: an idealized model study

    CERN Document Server

    Hertwig, Eileen; Fraedrich, Klaus

    2016-01-01

    A set of idealized experiments are performed to analyze the competing effects of declining atmospheric CO2 concentrations, the opening of an ocean gateway, and varying orbital parameters. These forcing mechanisms, which influence the global mean climate state, may have played a role for triggering climate transitions of the past (for example during the Eocene-Oligocene climate transition and the build-up of the Antarctic Ice Sheet). Sensitivity simulations with a coupled atmosphere-ocean general circulation model are conducted to test these three forcings and their roles for the global climate. The simulations are carried out under idealized conditions to focus on the essentials. The combination of all three forcings triggers a climate transition which resembles the onset of the Antarctic glaciation. In particular, the temperatures in the southern high latitudes decrease and snow accumulates constantly. Moreover, the relative importance of each possible forcing is explored. All three of the mechanisms (atmosp...

  20. Greenhouse effect simulator - An educational application

    Science.gov (United States)

    Machado, Alan Freitas; Viveiros, Bruno Martins; da Silva, Claudio Elias

    2016-12-01

    Using the program "Modellus", we intend to create a simple simulation to show the impacts that the Greenhouse Effect might have, in a didactic and friendly way, in order to expose this notions to high and middle school students. In order to do so, we created a program that will simulate a sweep, through the Troposphere, and create two lines in a graphic, one showing the temperatures behavior, in normal conditions, and the other showing how the temperature behaves in the presence of excess of Greenhouse gases. The main purpose of the project is to use the model in schools and try to make kids more conscious of their roles in our so society, showing them the consequences of the tendency of our acts, stimulating them to be more proactives to change the future.

  1. Diffusivity Models and Greenhouse Gases Fluxes from a Forest, Pasture, Grassland and Corn Field in Northern Hokkaido, Japan

    Institute of Scientific and Technical Information of China (English)

    N.V.NKONGOLO; R.HATANO; V.KAKEMBO

    2010-01-01

    Information on the most influential factors determining gas flux from soils is needed in predictive models for greenhouse gases emissions.We conducted an intensive soil and air sampling along a 2 000 m transect extending from a forest,pasture,grassland and corn field in Shizunai,Hokkaido (Japan),measured CO2,CH4,N2O and NO fluxes and calculated soil bulk density (ρb),air-filled porosity (fa) and total porosity (φ).Using diffusivity models based on either fa alone or on a combination of fa and φ,we predicted two pore space indices:the relative gas diffusion coefficient (Ds/Do) and the pore tortuosity factor (τ).The relationships between pore space indices (Dg/Do and τ) and CO2,CH4,N2O and NO fluxes were also studied.Results showed that the grassland had the highest ρb while fa and φ were the highest in the forest.CO2,CH4,N2O and NO fluxes were the highest in the grassland while N2O dominated in the corn field.Few correlations existed between fa,φ,ρb and gases fluxes while all models predicted that Ds/Do and τ significantly correlated with CO2 and CH4 with correlation coefficient (τ) ranging from 0.20 to 0.80.Overall,diffusivity models based on fa alone gave higher Ds/Do,lower τ and higher R2 and better explained the relationship between pore space indices (Ds/Do and τ) and gases fluxes.Inclusion of Ds/Do and τ in predictive models will improve our understanding of the dynamics of greenhouse gas fluxes from soils.Ds/Do and τ can be easily obtained by measurements of soil air and water and existing diffusivity models.

  2. 北方"四位一体"模式中日光温室结构的优化%Optimization of the Structural Parameters of Solar Greenhouse in the Tetrad-eco-agricultural Model in North China

    Institute of Scientific and Technical Information of China (English)

    葛一洪; 王惠生; 王清; 赵辉; 牛文慧; 乔汪砚

    2011-01-01

    Taking northern Shaanxi region as example, the tetrad-eco-agricultural model of sunlight greenhouse was studied and proposed the optimized structural parameters and tested its operating efficiency.The results indicated that, compared with the traditional greenhouse, the daily light intensity in the optimized greenhouse was higher, by 3 115 1x; the daily inside temperature raised 3.6 ℃; the temperature of anaerobic digestion was averagely higher by 0.5 ℃; the daily biogas production of digester increased 0.1 ma.%以陕北地区为例,对北方"四位一体"模式的日光温室进行研究,提出优化性的结构参数,并对其运行效果进行测定.结果表明,优化的日光温室比传统的日光温室,室内日均光照度提高3 115 lx;室内日均温度提高3.6℃;地下沼气池的日均发酵温度提高0.5℃;沼气池的日均产气量增加0.1 m3.

  3. Irrigation water consumption modelling of a soilless cucumber crop under specific greenhouse conditions in a humid tropical climate

    Directory of Open Access Journals (Sweden)

    Galo Alberto Salcedo

    Full Text Available ABSTRACT: The irrigation water consumption of a soilless cucumber crop under greenhouse conditions in a humid tropical climate has been evaluated in this paper in order to improve the irrigation water and fertilizers management in these specific conditions. For this purpose, a field experiment was conducted. Two trials were carried out during the years 2011 and 2014 in an experimental farm located in Vinces (Ecuador. In each trial, the complete growing cycle of a cucumber crop grown under a greenhouse was evaluated. Crop development was monitored and a good fit to a sigmoidal Gompertz type growth function was reported. The daily water uptake of the crop was measured and related to the most relevant indoor climate variables. Two different combination methods, namely the Penman-Monteith equation and the Baille equation, were applied. However, the results obtained with these combination methods were not satisfactory due to the poor correlation between the climatic variables, especially the incoming radiation, and the crop's water uptake (WU. On contrary, a good correlation was reported between the crop's water uptake and the leaf area index (LAI, especially in the initial crop stages. However, when the crop is fully developed, the WU stabilizes and becomes independent from the LAI. A preliminary model to simulate the water uptake of the crop was adjusted using the data obtained in the first experiment and then validated with the data of the second experiment.

  4. 基于单片机的大棚温湿度控制系统设计%SCM-based Temperature and Humidity Control System for Vegetable Greenhouse

    Institute of Scientific and Technical Information of China (English)

    易顺明; 赵海兰; 袁然

    2011-01-01

    An intelligent temperature/humidity control system was designed for vegetable greenhouses based on computer automatic control. The design thought of the system softwares and hardwares such as temperature/humidity acquisition system, temperature/humidity display, control system and heater control circuit are expoundcd. Taking DS18820 and HM1500LF as the temperature/humidity sensors , single chip microcomputer AT89S52 as a core of the system , the simulation of the system was performed with DELPHI software. The result shows that the intelligent temperature/humidity control system designed in the research has good human-computer interface, simple and convenient operation, high automation degree,low cost and good application foreground.%针对研究蔬菜大棚智能温湿度控制,设计了一种基于计算机自动控制的智能蔬菜大棚温湿度控制系统.详细阐述了该系统的温湿度采集、温湿度显示、控制系统等系统软硬件的设计思想,以DSl8820和HMl500LF作为温湿度传感器,以AT89S52单片机为系统核心,最后利用DELPHI软件进行系统仿真.该研究设计的蔬菜大棚智能温湿度控制系统人机界面良好,操作简单方便,自动化程度高,造价低廉,具有良好的应用前景和推广价值.

  5. Dissolved methane in rising main sewer systems: field measurements and simple model development for estimating greenhouse gas emissions.

    Science.gov (United States)

    Foley, Jeff; Yuan, Zhiguo; Lant, Paul

    2009-01-01

    At present, the potential generation of methane in wastewater collection systems is ignored under international greenhouse gas (GHG) accounting protocols, despite recent reports of substantial dissolved methane formation in sewers. This suggests that the current national GHG inventories for wastewater handling systems are likely to be underestimated for some situations. This study presents a new catalogue of field data on methane formation in rising main sewerage systems and proposes an empirically-fitted, theoretical model to predict dissolved methane concentrations, based upon the independent variables of pipeline geometry (i.e. surface area to volume ratio, A/V) and hydraulic retention time (HRT). Systems with longer HRT and/or larger A/V ratios are shown to have higher dissolved methane concentrations. This simple predictive model provides a means for water authorities to estimate the methane emissions from other pressurised sewerage systems of similar characteristics.

  6. Greenhouse gas penalty and incentive policies for a joint economic lot size model with industrial and transport emissions

    Directory of Open Access Journals (Sweden)

    Ivan Darma Wangsa

    2017-03-01

    Full Text Available This paper presents a joint economic lot size model for a single manufacturer-a single buyer. The purposed model involves the greenhouse gas emission from industrial and transport sectors. We divide the emission into two types, namely the direct and indirect emissions. In this paper, we consider the Government’s penalty and incentive policies to reduce the emission. We assume that the demand of the buyer is normally distributed and partially backordered. The objective is to minimize joint total cost incurred by a single manufacturer-a single buyer and involves the transportation costs of the freight forwarder. Transportation costs are the function of shipping weight, distance, fuel price and consumption with two transportation modes: truckload and less-than-truckload shipments. Finally, an algorithm procedure is proposed to determine the optimal order quantity, safety factor, actual shipping weight, total emission and frequency of deliveries. Numerical examples and analyses are given to illustrate the results.

  7. 南方塑料大棚冬春季温湿度的神经网络模拟%Neural Network Simulation on Air Temperature and Relative Humidity inside Plastic Greenhouse during Winter and Spring in Southern China

    Institute of Scientific and Technical Information of China (English)

    李倩; 申双和; 曹雯; 邹学智

    2012-01-01

    Based on the meteorological data both inside and outside the plastic greenhouse in Cixi, Zhejiang province and agricultural meteorological experimental station of Nanjing University of Information Science and Technology, three BP neural network models were established, which the input variable was chosen as radiation solar outdoor, air temperature, relative humidity and wind speed, and output variable was chosen as temperature indoor and relative humidity. The results showed that all of the root mean square error (RMSE) between trained air temperature and measured value from three models was no more than 2℃ and the relative error (RE) no more than 4% respectively. Both RMSE and RE between trained relative humidity and measured value was no more than 7 percent points and 7% . All of the RMSE between predicted air temperature and measured value from three models was 2℃ approximately, and their RE was no more than 6% in spring, less than that in winter. RMSE and RE predicated relative humidity and measured value was no more than 7 percent points and 9% respectively. The results indicated that three BP neural network models had quite precisely for predicting temperature indoor and relative humidity in plastic greenhouse, which could meet the forecast requirements for plastic greenhouse microclimate.%利用浙江省慈溪市草莓塑料大棚和南京信息工程大学农业气象试验站番茄塑料大棚的小气候观测数据及气象站资料,建立3个以棚外辐射、温度、相对湿度和风速为输入变量,棚内温度和相对湿度为输出变量的BP神经网络预测模型.结果表明,3个模型气温训练值与实测值的均方根误差(RMSE)都在2℃以内,相对误差都在4%左右;相对湿度训练值的RMSE都在7个百分点以内,相对误差不超过7%.利用此模型得到的气温预测值与实测值的RMSE都在2℃左右,冬季气温的相对误差较大,春季通风和不通风模型气温的相对误差不超过6%;

  8. A large-scale solar greenhouse dryer using polycarbonate cover: Modeling and testing in a tropical environment of Lao People's Democratic Republic

    Energy Technology Data Exchange (ETDEWEB)

    Janjai, Serm; Intawee, Poolsak; Kaewkiew, Jinda; Sritus, Chanoke [Solar Energy Research Laboratory, Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand); Khamvongsa, Vathsana [Department of Physics, Faculty of Natural Science, National University of Laos, P O Box 7322, Vientiane (Lao People' s Democratic Republic)

    2011-03-15

    A large-scale solar greenhouse dryer with a loading capacity of 1000 kg of fruits or vegetables has been developed and tested at field levels. The dryer has a parabolic shape and the dryer is covered with polycarbonate sheets. The base of the dryer is a black concrete floor with an area of 7.5 x 20.0 m{sup 2}. Nine DC fans powered by three 50-W solar cell modules are used to ventilate the dryer. The dryer was installed at Champasak (15.13 N, 105.79 E) in Lao People's Democratic Republic (Lao PDR). It is routinely used to dry chilli, banana and coffee. To assess the experimental performances of the dryer, air temperature, air relative humidity and product moisture contents were measured. One thousand kilograms of banana with the initial moisture content of 68% (wb) was dried within 5 days, compared to 7 days required for natural sun drying with the same weather conditions. Also three hundred kilograms of chilli with the initial moisture content of 75% (wb) was dried within 3 days while the natural sun drying needed 5 days. Two hundred kilograms of coffee with the initial moisture content of 52% (wb) was dried within 2 days as compared to 4 days required for natural sun drying. The chilli, coffee and banana dried in this dryer were completely protected from insects, animals and rain. Furthermore, good quality of dried products was obtained. The payback period of the dryer is estimated to be 2.5 years. A system of partial differential equations describing heat and moisture transfer during drying of chilli, coffee and banana in the greenhouse dryer was developed. These equations were solved by using the finite different method. The simulated results agree well with the experimental data. This model can be used to provide the design data for this type of dryer in other locations. (author)

  9. CO2, the greenhouse effect and global warming: from the pioneering work of Arrhenius and Callendar to today's Earth System Models.

    Science.gov (United States)

    Anderson, Thomas R; Hawkins, Ed; Jones, Philip D

    2016-09-01

    Climate warming during the course of the twenty-first century is projected to be between 1.0 and 3.7°C depending on future greenhouse gas emissions, based on the ensemble-mean results of state-of-the-art Earth System Models (ESMs). Just how reliable are these projections, given the complexity of the climate system? The early history of climate research provides insight into the understanding and science needed to answer this question. We examine the mathematical quantifications of planetary energy budget developed by Svante Arrhenius (1859-1927) and Guy Stewart Callendar (1898-1964) and construct an empirical approximation of the latter, which we show to be successful at retrospectively predicting global warming over the course of the twentieth century. This approximation is then used to calculate warming in response to increasing atmospheric greenhouse gases during the twenty-first century, projecting a temperature increase at the lower bound of results generated by an ensemble of ESMs (as presented in the latest assessment by the Intergovernmental Panel on Climate Change). This result can be interpreted as follows. The climate system is conceptually complex but has at its heart the physical laws of radiative transfer. This basic, or "core" physics is relatively straightforward to compute mathematically, as exemplified by Callendar's calculations, leading to quantitatively robust projections of baseline warming. The ESMs include not only the physical core but also climate feedbacks that introduce uncertainty into the projections in terms of magnitude, but not sign: positive (amplification of warming). As such, the projections of end-of-century global warming by ESMs are fundamentally trustworthy: quantitatively robust baseline warming based on the well-understood physics of radiative transfer, with extra warming due to climate feedbacks. These projections thus provide a compelling case that global climate will continue to undergo significant warming in response

  10. Sugarcane agricultural-industrial facilities and greenhouses integration

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Andres da [Estufas Agricolas Comercio e Assessoria Ltda. (EACEA), SP (Brazil)

    2012-07-01

    This chapter approaches Brazilian greenhouse market and technology, food market trends, integration of bioethanol distilleries with GH production, recovering CO{sub 2} from fermentation process, recovering low temperature energy, using vinasse and bagasse in GH processes, examples of integrated GH in the world, a tomato integrated GH study case, and a business model.

  11. The Impact of Secondary School Students' Preconceptions on the Evolution of Their Mental Models of the Greenhouse Effect and Global Warming

    Science.gov (United States)

    Reinfried, Sibylle; Tempelmann, Sebastian

    2014-01-01

    This paper provides a video-based learning process study that investigates the kinds of mental models of the atmospheric greenhouse effect 13-year-old learners have and how these mental models change with a learning environment, which is optimised in regard to instructional psychology. The objective of this explorative study was to observe and…

  12. The Impact of Secondary School Students' Preconceptions on the Evolution of Their Mental Models of the Greenhouse Effect and Global Warming

    Science.gov (United States)

    Reinfried, Sibylle; Tempelmann, Sebastian

    2014-01-01

    This paper provides a video-based learning process study that investigates the kinds of mental models of the atmospheric greenhouse effect 13-year-old learners have and how these mental models change with a learning environment, which is optimised in regard to instructional psychology. The objective of this explorative study was to observe and…

  13. Whole-farm models to quantify greenhouse gas emissions and their potential use for linking climate change mitigation and adaptation in temperate grassland ruminant-based farming systems

    DEFF Research Database (Denmark)

    del Prado, A; Crosson, P; Olesen, Jørgen E;

    2013-01-01

    The farm level is the most appropriate scale for evaluating options for mitigating greenhouse gas (GHG) emissions, because the farm represents the unit at which management decisions in livestock production are made. To date, a number of whole farm modelling approaches have been developed to quant......The farm level is the most appropriate scale for evaluating options for mitigating greenhouse gas (GHG) emissions, because the farm represents the unit at which management decisions in livestock production are made. To date, a number of whole farm modelling approaches have been developed...

  14. Estimating soil carbon change and biofuel life-cycle greenhouse gas emissions with economic, ecosystem and life-cycle models

    Science.gov (United States)

    Qin, Z.; Dunn, J.; Kwon, H. Y.; Mueller, S.; Wander, M.

    2015-12-01

    Land-use change (LUC) resulting from biofuel feedstock production can alter soil organic carbon (SOC) stocks of lands producing those crops and the crops they displace, possibly resulting in greenhouse gas (GHG) emissions. LUC GHG emissions included in biofuel life cycle analysis (LCA) have at times been estimated to be so great that biofuels did not offer a greenhouse gas reduction compared to conventional fossil fuels. To improve the accuracy of emissions estimates, SOC changes must be considered at a finer spatial resolution and take into account climate, soil, land use and management factors. This study reports on the incorporation of global LUC as predicted by a computable general equilibrium model (i.e., GTAP) and spatially-explicit modeled SOC estimates (using surrogate CENTURY) for various biofuel feedstock scenarios into a widely-used LCA model (i.e., GREET). Resulting estimates suggest: SOC changes associated with domestic corn production might contribute 2-6% or offset as much as 5% of total corn ethanol life-cycle GHG emissions. On the other hand, domestic LUC GHG emissions for switchgrass ethanol have the potential offset up to 60% of GHG emissions in the fuel's life cycle. Further, large SOC sequestration is predicted for Miscanthus feedstock production, enabling Miscanthus-based ethanol systems to offset all life-cycle GHG emissions and create a net carbon sink. LUC GHG emissions for ethanol derived from corn stover are small compared to other sources. Total life-cycle GHG emissions (g CO2eq MJ-1, 100cm soil) were estimated to be 59-66 for corn ethanol, 14 for stover ethanol, 18-26 for switchgrass ethanol, and -7 - -0.6 for Miscanthus ethanol.

  15. Dynamic Model of High Temperature PEM Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2007-01-01

    cathode air cooled 30 cell HTPEM fuel cell stack developed at the Institute of Energy Technology at Aalborg University. This fuel cell stack uses PEMEAS Celtec P-1000 membranes, runs on pure hydrogen in a dead end anode configuration with a purge valve. The cooling of the stack is managed by running...... conduction through stack insulation, cathode air convection and heating of the inlet gasses in manifold. Various measurements are presented to validate the model predictions of the stack temperatures....

  16. Last interglacial temperature evolution – a model inter-comparison

    Directory of Open Access Journals (Sweden)

    P. Bakker

    2013-03-01

    Full Text Available There is a growing number of proxy-based reconstructions detailing the climatic changes that occurred during the last interglacial period (LIG. This period is of special interest, because large parts of the globe were characterized by a warmer-than-present-day climate, making this period an interesting test bed for climate models in light of projected global warming. However, mainly because synchronizing the different palaeoclimatic records is difficult, there is no consensus on a global picture of LIG temperature changes. Here we present the first model inter-comparison of transient simulations covering the LIG period. By comparing the different simulations, we aim at investigating the common signal in the LIG temperature evolution, investigating the main driving forces behind it and at listing the climate feedbacks which cause the most apparent inter-model differences. The model inter-comparison shows a robust Northern Hemisphere July temperature evolution characterized by a maximum between 130–125 ka BP with temperatures 0.3 to 5.3 K above present day. A Southern Hemisphere July temperature maximum, −1.3 to 2.5 K at around 128 ka BP, is only found when changes in the greenhouse gas concentrations are included. The robustness of simulated January temperatures is large in the Southern Hemisphere and the mid-latitudes of the Northern Hemisphere. For these regions maximum January temperature anomalies of respectively −1 to 1.2 K and −0.8 to 2.1 K are simulated for the period after 121 ka BP. In both hemispheres these temperature maxima are in line with the maximum in local summer insolation. In a number of specific regions, a common temperature evolution is not found amongst the models. We show that this is related to feedbacks within the climate system which largely determine the simulated LIG temperature evolution in these regions. Firstly, in the Arctic region, changes in the summer sea-ice cover control the evolution of LIG winter

  17. Estimate of soil organic carbon and greenhouse gas emissions in para rubber (Hevea brasiliensis Mull. Arg plantation by DNDC model in Upland Area Northern, Thailand

    Directory of Open Access Journals (Sweden)

    C. Podong

    2014-12-01

    Full Text Available The process-oriented model DNDC describing biogeochemical cycling of C and N and greenhouse gases (GHGs fluxes carbon dioxide (CO2, nitrous oxide (N2O, nitric oxide (NO in para rubber plantation was applied to simulate carbon sequestration and GHGs emissions in a para rubber plantation of small watershed in the lower part of northern Thailand. The results indicated that the simulated gross primary production (GPP and soil organic carbon (SOC of the para rubber plantation was strongly affected by temperature. The annual total GPP was 2,765.8 kg C /ha/yr, and net primary production (NPP was 2,032.4. The SOC in 0-10 cm. were 4,983 kg C /ha/yr for 2011.The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emission was 976.53 kg C /ha/yr for 2011, the simulated annual total N2O emissions from the plantation's soil was 10.51 kg N ha-1yr-1 for 2011, the annual total NO emissions were 0.87 kg N /ha/yr for 2011, and the annual Dissolved Organic Matter (DOM leaching was 0.23 kg C /ha/yr.

  18. Gaining ground in the modeling of land-use change greenhouse gas emissions associated with biofuel production

    Science.gov (United States)

    Dunn, J.; Mueller, S.; Kwon, H.; Wang, M.; Wander, M.

    2012-12-01

    Land-use change (LUC) resulting from biofuel feedstock production and the associated greenhouse gas (GHG) emissions are a hotly-debated aspect of biofuels. Certainly, LUC GHG emissions are one of the most uncertain elements in life cycle analyses (LCA) of biofuels. To estimate LUC GHG emissions, two sets of data are necessary. First, information on the amount and type of land that is converted to biofuel feedstock production is required. These data are typically generated through application of computable general equilibrium (CGE) models such as Purdue University's Global Trade Analysis Project (GTAP) model. Second, soil carbon content data for the affected land types is essential. Recently, Argonne National Laboratory's Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) has been updated with CGE modeling results that estimate the amount and type of LUC world-wide from production of ethanol from corn, corn stover, miscanthus, and switchgrass (Mueller et al. 2012). Moreover, we have developed state-specific carbon content data, determined through modeling with CENTURY, for the two most dominant soil types in the conterminous 48 U.S. states (Kwon et al. 2012) to enable finer-resolution results for domestic LUC GHG emissions for these ethanol production scenarios. Of the feedstocks examined, CCLUB estimates that LUC GHG emissions are highest for corn ethanol (9.1 g CO2e/MJ ethanol) and lowest for miscanthus (-12 g CO2e/MJ ethanol). We will present key observations from CCLUB results incorporated into Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy use in Transportation (GREET) model, which is a LCA tool for transportation fuels and advanced vehicle technologies. We will discuss selected issues in this modeling, including the sensitivity of domestic soil carbon emission factors to modeling parameters and assumptions about the fate of harvested wood products. Further, we will discuss efforts to update CCLUB with county

  19. Temperature Modelling of the Biomass Pretreatment Process

    DEFF Research Database (Denmark)

    2012-01-01

    In a second generation biorefinery, the biomass pretreatment stage has an important contribution to the efficiency of the downstream processing units involved in biofuel production. Most of the pretreatment process occurs in a large pressurized thermal reactor that presents an irregular temperature...... distribution. Therefore, an accurate temperature model is critical for observing the biomass pretreatment. More than that, the biomass is also pushed with a constant horizontal speed along the reactor in order to ensure a continuous throughput. The goal of this paper is to derive a temperature model...

  20. A numerical model for ground temperature determination

    Science.gov (United States)

    Jaszczur, M.; Polepszyc, I.; Biernacka, B.; Sapińska-Śliwa, A.

    2016-09-01

    The ground surface temperature and the temperature with respect to depth are one of the most important issues for geotechnical and environmental applications as well as for plants and other living organisms. In geothermal systems, temperature is directly related to the energy resources in the ground and it influences the efficiency of the ground source system. The ground temperature depends on a very large number of parameters, but it often needs to be evaluated with good accuracy. In the present work, models for the prediction of the ground temperature with a focus on the surface temperature at which all or selected important ground and environmental phenomena are taken into account have been analysed. It has been found that the simplest models and the most complex model may result in a similar temperature variation, yet at a very low depth and for specific cases only. A detailed analysis shows that taking into account different types of pavement or a greater depth requires more complex and advanced models.

  1. Emission of carbon. A most important component for greenhouse effect in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Milaev, V.B.; Kopp, I.Z.; Yasenski, A.N. [Scientific Research Inst. of Atmospheric Air Protection, St. Petersburg (Russian Federation)

    1995-12-31

    Greenhouse effect is most often defined as the probabilities of atmospheric air quasiequilibrium temperature increase as a result of air pollution due to emission of anthropogenic gaseous substances which are usually called `greenhouse gases`. Among greenhouse gases are primarily considered several gaseous substances which contain carbon atoms: carbon oxide, carbon dioxide and methane (CO, CO{sub 2} and CH{sub 4}), and chlorinated and fluorinated hydrocarbons (freons) spectra of which are transparent to solar radiation, but absorb and reradiate longwave radiation causing disturbance of quasistationary thermal regieme of the atmosphere. Qualitative estimates of the income and relative roles of different substances in occurrence of greenhouse effect differ considerable. At the modern state of knowledge the problem of greenhouse effect and greenhouse gases is considered in several aspects. The most widespread and investigated is climatic or meteorological aspect, it is discussed in a number of international works. Rather pressing is thermal physics aspect of the problem of estimating greenhouse effect, which consists in correct construction of a calculation model and usage of the most representative experimental data, since analytical methods require many assumptions, introduction of which may lead to results which differ very much. Bearing these uncertainties in mind the UNEP/WMO/ICSU conference has included into the number of the most urgent tasks in the study of greenhouse effect, the problem of determining the priority of factors which cause greenhouse effect, which in its turn predetermines the necessity to substantiate the methods of selection and criterion of comparative evaluation of such factors. (author)

  2. 后墙立体栽培草莓提高冬季日光温室内温度%Back wall stereo-cultivation of strawberry improves temperature in Chinese solar greenhouse in winter

    Institute of Scientific and Technical Information of China (English)

    宋卫堂; 栗亚飞; 曲明山; 何华名; 郑亮; 邢文鑫

    2013-01-01

    In Chinese solar greenhouse production, pipe stereo-cultivation of vegetables or strawberry on the greenhouse back wall could improve the space utilization and increase the cultivation area and yield. However, it is possible that shading of pipes and plantings may reduce the back wall heat storage and result in the decreasing of internal temperature of the greenhouse in winter. The objective of this study is to find out whether the back wall pipe cultivation affects the temperature variations of solar greenhouse in winter. In this article, the experiment was conducted in two solar greenhouses of a strawberry park in suburb Beijing. The structure type, growing conditions and management methods of the two experimental greenhouses are exactly the same. Pipe strawberry cultivation facility was installed on the back wall (2.3m high) in one solar greenhouse. The pipe cultivation facility is composed of 4 rows of horizontal PVC pipe, center distance of each row is 40 cm, diameter of the pipe is 160 mm with 9cm width’s notch on the upper side. Cultivation substrate (peat:perlite:vermiculite=1:1:1 (v/v), depth is 10 cm) and drip irrigation to fertilizer nutrient solution were used. Five measurement points were arranged in both greenhouses, to measure the temperature of strawberry growth canopy and 1.5 m above the ground. Temperature condition of the two greenhouses for 31 days (from Jan. 20th, 2013 to Feb. 20th, 2013) was continuously monitored, and the temperature variations of solar greenhouse with equipment (ESG) and solar greenhouse with no equipment (NSG) of three typical climatic conditions (sunny, cloudy and snowy) were analyzed.The results showed that the monthly mean temperature in ESG was 0.84℃higher than that in NSG, and the maximum and minimum of daily temperature difference was 2.22℃and 0.14℃, respectively. In sunny days, daily mean canopy temperature and daily mean air temperature at 1.5m height in ESG were 10.68℃ and 11.04℃, but they were 10.68

  3. Greenhouse gas emissions and soil properties following amendment with manure-derived biochars: Influence of pyrolysis temperature and feedstock type.

    Science.gov (United States)

    Subedi, Raghunath; Taupe, Natalie; Pelissetti, Simone; Petruzzelli, Laura; Bertora, Chiara; Leahy, James J; Grignani, Carlo

    2016-01-15

    Manure-derived biochars can offer a potential option for the stabilization of manure, while mitigating climate change through carbon sequestration and the attenuation of nitrous oxide emission. A laboratory incubation study was conducted to assess the effects of four different manure-derived biochars produced from different feedstocks (poultry litter and swine manure) at different temperatures (400 or 600 °C). A commonly available standard wood chip biochar, produced at a greater temperature (1000 °C), and non-amended treatments were used as references. Two different soils (sandy and silt-loam) were amended with 2% (w/w) biochar on a dry soil weight basis (corresponding to 20 Mg ha(-1)), with the soil moisture being adjusted to 75% saturation level. After a pre-incubation period (21 days), 170 kg N ha(-1) of NH4NO3 fertilizer was added. Measurements of CO2, N2O, CH4 emissions and soil N mineralisation were carried out on different days during the 85 days of incubation. The net C mineralization and N2O emissions from both soils amended with poultry litter biochar at 400 °C were significantly greater than the other biochar treatments. Nitrate availability was greater in both soils in which the manure-derived biochar was used instead of the standard biochar. All of the biochars increased the pH of the silt-loam, sub-acid soil, but failed to improve the cation exchange capacities (CEC) in either soil. Total C and N, P, K and Mg (except Ca) were significantly increased in the manure-derived biochar amended soils, compared to the Control, and were positively correlated to the biochar nutrient contents. This study indicates that the soil application of biochar engenders effects that can vary considerably according to the biochar properties, as determined on the basis of the feedstock types and process conditions. Low-temperature biochar production from manure represents a possible way of producing a soil amendment that can stabilize C while supplying a

  4. 基于改进型极限学习机的日光温室温湿度预测与验证%Verification and forecasting of temperature and humidity in solar greenhouse based on improved extreme learning machine algorithm

    Institute of Scientific and Technical Information of China (English)

    邹伟东; 张百海; 姚分喜; 贺超兴

    2015-01-01

    Solar greenhouse temperature and humidity models play an important role in its structure design and control. Solar greenhouses are multi-input and multi-output (MIMO) systems, and they are highly nonlinear and strongly coupled systems that are largely influenced by the outside weather (such as wind speed, outside temperature and humidity) and many other practical constraints (such as blowing and moistening cycle). Therefore, solar greenhouse temperature and humidity models are difficult to establish by mechanism analysis methods. Due to its ability to approximate complex nonlinear mapping directly from the input samples, neural network can provide models for many kinds of natural and artificial phenomena that are difficult to handle using classical parametric techniques. Among many kinds of neural networks, extreme learning machine (ELM) for single-hidden layer feed forward neural networks has been studied more thoroughly. But there are limitations existing in ELM such as fixed hidden-layer activation function and overfitting when minimizing training error. In order to achieve comprehensive control of temperature and humidity in the solar greenhouse and improve prediction accuracy, an improved ELM based on orthonormal basis function is proposed in the paper. First, it determines the number of the nodes in hidden layer by using empirical mode decomposition (EMD); second, on the basis of statistical learning theory combined with the empirical risk and structural risk, it takes minimal value of the sum of the minimum output weight and the minimum error; third, it identifies the greenhouse microclimate environmental factors. The prediction model of temperature and humidity is established by the improved ELM. The proposed method is tested in the solar greenhouse of Vegetable and Fruit Research Institution of Chinese Academy of Agricultural Sciences, which is located in 40°07′N, 116°09′E. According to the characteristics of solar greenhouse environment, the inputs

  5. Computer Modeling of Planetary Surface Temperatures in Introductory Astronomy Courses

    Science.gov (United States)

    Barker, Timothy; Goodman, J.

    2013-01-01

    Barker, T., and Goodman, J. C., Wheaton College, Norton, MA Computer modeling is an essential part of astronomical research, and so it is important that students be exposed to its powers and limitations in the first (and, perhaps, only) astronomy course they take in college. Building on the ideas of Walter Robinson (“Modeling Dynamic Systems,” Springer, 2002) we have found that STELLA software (ISEE Systems) allows introductory astronomy students to do sophisticated modeling by the end of two classes of instruction, with no previous experience in computer programming or calculus. STELLA’s graphical interface allows students to visualize systems in terms of “flows” in and out of “stocks,” avoiding the need to invoke differential equations. Linking flows and stocks allows feedback systems to be constructed. Students begin by building an easily understood system: a leaky bucket. This is a simple negative feedback system in which the volume in the bucket (a “stock”) depends on a fixed inflow rate and an outflow that increases in proportion to the volume in the bucket. Students explore how changing inflow rate and feedback parameters affect the steady-state volume and equilibration time of the system. This model is completed within a 50-minute class meeting. In the next class, students are given an analogous but more sophisticated problem: modeling a planetary surface temperature (“stock”) that depends on the “flow” of energy from the Sun, the planetary albedo, the outgoing flow of infrared radiation from the planet’s surface, and the infrared return from the atmosphere. Students then compare their STELLA model equilibrium temperatures to observed planetary temperatures, which agree with model ones for worlds without atmospheres, but give underestimates for planets with atmospheres, thus introducing students to the concept of greenhouse warming. We find that if we give the students part of this model at the start of a 50-minute class they are

  6. Multiple Temperature Model for Near Continuum Flows

    Energy Technology Data Exchange (ETDEWEB)

    XU, Kun; Liu, Hongwei [Hong Kong University of Science and Technology, Kowloon (Hong Kong); Jiang, Jianzheng [Chinese Academy ofSciences, Beijing (China)

    2007-09-15

    In the near continuum flow regime, the flow may have different translational temperatures in different directions. It is well known that for increasingly rarefied flow fields, the predictions from continuum formulation, such as the Navier-Stokes equations, lose accuracy. These inaccuracies may be partially due to the single temperature assumption in the Navier-Stokes equations. Here, based on the gas-kinetic Bhatnagar-Gross-Krook (BGK) equation, a multitranslational temperature model is proposed and used in the flow calculations. In order to fix all three translational temperatures, two constraints are additionally proposed to model the energy exchange in different directions. Based on the multiple temperature assumption, the Navier-Stokes relation between the stress and strain is replaced by the temperature relaxation term, and the Navier-Stokes assumption is recovered only in the limiting case when the flow is close to the equilibrium with the same temperature in different directions. In order to validate the current model, both the Couette and Poiseuille flows are studied in the transition flow regime.

  7. Modelling the effect of the position of cooling elements on the vertical profile of transpiration in a greenhouse tomato crop

    NARCIS (Netherlands)

    Stanghellini, C.; Dieleman, J.A.; Driever, S.M.; Marcelis, L.F.M.

    2012-01-01

    Semi-closed greenhouse management may increase greenhouse productivity. However, it relies on the application of mechanical cooling. Cooling can be applied from above or below the canopy. The positioning of the cooling affects the vertical climate profile in the canopy. In order to determine how thi

  8. Design and Development a Control and Monitoring System for Greenhouse Conditions Based-On Multi Agent System

    Directory of Open Access Journals (Sweden)

    Seyed Hamidreza Kasaei

    2011-12-01

    Full Text Available The design of a multi-agent system for integrated management of greenhouse production is described. The model supports the integrated greenhouse production, with targets set to quality and quantity of produce with the minimum possible cost in resources and environmental consequences.
    In this paper, we propose a real time and robust system for monitoring and control of the greenhouse condition which can automatically control of greenhouse temperature, lights, humidity, CO2 concentration, sunshine, pH, salinity, water available, soil temperature and soil nutrient for efficient production. We will propose a multi-agent methodology for integrated management systems in greenhouses. In this regards wireless sensor networks play a vital role to monitor
    greenhouse and environment parameters. Each control process of the greenhouse environment is modeled as an autonomous agent with its own inputs, outputs and its own interactions with the other agents. Each agent acts autonomously, as it knows a priori the desired environmental setpoints. Many researchers have been making attempts to develop the greenhouse environment management system. The existing environment management systems are bulky, very costly and difficult to maintain. In the last years, Multi Agent Systems and Wireless Sensor Networks are becoming important solutions to this problem. This paper describes the implementation and
    configuration of the wireless sensor network to monitor and control various parameter of greenhouse. The developed system is simple, cost effective, and easily installable.

  9. Model study on applicability of a semi closed greenhouse concept in Almeria: Effects on greenhouse climate, crop yield and resource use efficiency

    NARCIS (Netherlands)

    Ooster, van 't A.; Ieperen, van W.; Kalaitzoglou, P.

    2012-01-01

    The application of climate control equipment is becoming increasingly popular in Mediterranean protected horticulture. New climate control techniques reduce ventilation requirement and, thus, increase the benefits of carbon dioxide fertilization. Moreover, temperature extremes are prevented. Improve

  10. A 'Big leaf, big fruit, big substrate' model for experiments on receding horizon optimal control of nutrient supply to greenhouse tomato

    NARCIS (Netherlands)

    Straten, van G.; Vanthoor, B.H.E.; Willigenburg, van L.G.; Elings, A.

    2006-01-01

    A dynamic model was set up to describe the mineral content, fruit dry matter content, and biomass of greenhouse tomato, for use in an experiment aiming at controlling the fertigation so as to reach the best compromise between disinfection costs of the recycled water and income from fruit fresh weigh

  11. Development and Application of a Life Cycle-Based Model to Evaluate Greenhouse Gas Emissions of Oil Sands Upgrading Technologies.

    Science.gov (United States)

    Pacheco, Diana M; Bergerson, Joule A; Alvarez-Majmutov, Anton; Chen, Jinwen; MacLean, Heather L

    2016-12-20

    A life cycle-based model, OSTUM (Oil Sands Technologies for Upgrading Model), which evaluates the energy intensity and greenhouse gas (GHG) emissions of current oil sands upgrading technologies, is developed. Upgrading converts oil sands bitumen into high quality synthetic crude oil (SCO), a refinery feedstock. OSTUM's novel attributes include the following: the breadth of technologies and upgrading operations options that can be analyzed, energy intensity and GHG emissions being estimated at the process unit level, it not being dependent on a proprietary process simulator, and use of publicly available data. OSTUM is applied to a hypothetical, but realistic, upgrading operation based on delayed coking, the most common upgrading technology, resulting in emissions of 328 kg CO2e/m(3) SCO. The primary contributor to upgrading emissions (45%) is the use of natural gas for hydrogen production through steam methane reforming, followed by the use of natural gas as fuel in the rest of the process units' heaters (39%). OSTUM's results are in agreement with those of a process simulation model developed by CanmetENERGY, other literature, and confidential data of a commercial upgrading operation. For the application of the model, emissions are found to be most sensitive to the amount of natural gas utilized as feedstock by the steam methane reformer. OSTUM is capable of evaluating the impact of different technologies, feedstock qualities, operating conditions, and fuel mixes on upgrading emissions, and its life cycle perspective allows easy incorporation of results into well-to-wheel analyses.

  12. Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate_N simulation model.

    Science.gov (United States)

    Guo, Ruiying; Nendel, Claas; Rahn, Clive; Jiang, Chunguang; Chen, Qing

    2010-06-01

    Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-Rotate_N simulation model. EU-Rotate_N was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Greenhouse Warming Research

    DEFF Research Database (Denmark)

    Sørensen, Bent Erik

    2016-01-01

    The changing greenhouse effect caused by natural and anthropogenic causes is explained and efforts to model the behavior of the near-surface constituents of the Earth's land, ocean and atmosphere are discussed. Emissions of various substances and other aspects of human activity influence the gree......The changing greenhouse effect caused by natural and anthropogenic causes is explained and efforts to model the behavior of the near-surface constituents of the Earth's land, ocean and atmosphere are discussed. Emissions of various substances and other aspects of human activity influence...... the greenhouse warming, and the impacts of the warming may again impact the wellbeing of human societies. Thus physical modeling of the near-surface ocean-soil-atmosphere system cannot be carried out without an idea of the development of human activities, which is done by scenario analysis. The interactive...... nature of the natural and the human system calls for an extremely complex analysis, in order to predict the outcome of various proposed changes in human behavior. This includes halting activities that most influence the climate and finding workable alternatives to these activities, or adapting to climate...

  14. Design of Early Warning System for Low Temperature and Sparse Sunlight Disaster in Solar Greenhouse%日光温室低温寡照灾害监测预警系统设计

    Institute of Scientific and Technical Information of China (English)

    关福来; 杜克明; 魏瑞江; 孙忠富

    2009-01-01

    根据多年日光温室气象生态观测资料,总结了温室黄瓜和番茄低温寡照灾害指标,结合远程环境监控技术,建立了日光温室低温寡照灾害的监测预警系统,并在河北日光温室蔬菜生产中进行了测试和初步应用.结果表明,该系统可对低温寡照所发生的范围及强度等进行动态监测预警,并可通过自动生成word文档形式提供信息服务,在灾害诊断预警中具有较好的应用前景.%According to the eco-meteorological data observed for many years in Chinese solar greenhouses, the disaster index and grades of low temperature and sparse sunlight for cucumber and tomato in the greenhouse were summarized. The weather disaster early warning system integrated with remote monitoring technology was established for low temperature and sparse sunlight in the greenhouse, and preliminarily validated and applied in greenhouse vegetable production in Hebei Province. The results showed that this system could provide dynamically early prediction for warning the range and intensity of low temperature and sparse sunlight occurring in the greenhouse. At the same time, automatically created MS word document format for information service could proved wide applicable perspective in disaster diagnosis and forecast.

  15. Comparison of Different Fuel Temperature Models

    Energy Technology Data Exchange (ETDEWEB)

    Weddig, Beatrice

    2003-02-01

    The purpose of this work is to improve the performance of the core calculation system used in Ringhals for in-core fuel management. It has been observed that, whereas the codes yield results that are in good agreement with measurements when the core operates at full nominal power, this agreement deteriorates noticeably when the reactor is running at reduced power. This deficiency of the code system was observed by comparing the calculated and measured boron concentrations in the moderator of the PWR. From the neutronic point of view, the difference between full power and reduced power in the same core is the different temperature of the fuel and the moderator. Whereas the coolant temperature can be measured and is thus relatively well known, the fuel temperature is only inferred from the moderator temperature as well as neutron physics and heat transfer calculations. The most likely reason for the above mentioned discrepancy is therefore the uncertainty of the fuel temperature at low power, and hence the incorrect calculation of the fuel temperature reactivity feedback through the so called Doppler effect. To obtain the fuel temperature at low power, usually some semi-empirical relations, sometimes called correlations, are used. The above-mentioned inaccuracy of the core calculation procedures can thus be tracked down to the insufficiency of these correlations. Therefore, the suggestion is that the above mentioned deficiency of the core calculation codes can be eliminated or reduced if the fuel temperature correlations are improved. An improved model, called the 30% model, is implemented in SIMULATE-3, the core calculation code used at Ringhals. The accuracy of the 30% model was compared to that of the present model by considering a number of cases, where measured values of the boron concentration at low power were available, and comparing them with calculated values using both the present and the new model. It was found that on the whole, the new fuel temperature

  16. Temperature Dependent Residual Stress Models for Ultra-High-Temperature Ceramics on High Temperature Oxidation

    Science.gov (United States)

    Wang, Ruzhuan; Li, Weiguo

    2016-11-01

    The strength of SiC-depleted layer of ultra-high-temperature ceramics on high temperature oxidation degrades seriously. The research for residual stresses developed within the SiC-depleted layer is important and necessary. In this work, the residual stress evolutions in the SiC-depleted layer and the unoxidized substrate in various stages of oxidation are studied by using the characterization models. The temperature and oxidation time dependent mechanical/thermal properties of each phase in SiC-depleted layer are considered in the models. The study shows that the SiC-depleted layer would suffer from large tensile stresses due to the great temperature changes and the formation of pores on high temperature oxidation. The stresses may lead to the cracking and even the delamination of the oxidation layer.

  17. Temperature Dependent Residual Stress Models for Ultra-High-Temperature Ceramics on High Temperature Oxidation

    Science.gov (United States)

    Wang, Ruzhuan; Li, Weiguo

    2017-08-01

    The strength of SiC-depleted layer of ultra-high-temperature ceramics on high temperature oxidation degrades seriously. The research for residual stresses developed within the SiC-depleted layer is important and necessary. In this work, the residual stress evolutions in the SiC-depleted layer and the unoxidized substrate in various stages of oxidation are studied by using the characterization models. The temperature and oxidation time dependent mechanical/thermal properties of each phase in SiC-depleted layer are considered in the models. The study shows that the SiC-depleted layer would suffer from large tensile stresses due to the great temperature changes and the formation of pores on high temperature oxidation. The stresses may lead to the cracking and even the delamination of the oxidation layer.

  18. Atmospheric observations and inverse modelling for quantifying emissions of point-source synthetic greenhouse gases in East Asia

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Muhle, Jens; Weiss, Ray

    2017-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacements that are emitted from fugitive and mobile emission sources, these gases are mostly emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane (HCFC-22) factories (HFC-23). In this work we show that atmospheric measurements can serve as a basis to calculate emissions of these gases and to highlight emission 'hotspots'. We use measurements from one Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites at Gosan on Jeju Island in the Republic of Korea. This site measures CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over seven years between 2008 and 2015. We show that our 'top-down' emission estimates for NF3 and CF4 are significantly larger than 'bottom-up' estimates in the EDGAR emissions inventory (edgar.jrc.ec.europa.eu). For example we calculate South Korean emissions of CF4 in 2010 to be 0.29±0.04 Gg/yr, which is significantly larger than the Edgar prior emissions of 0.07 Gg/yr. Further, inversions for several separate years indicate that emission hotspots can be found without prior spatial information. At present these gases make a small contribution to global radiative forcing, however, given

  19. Interpolation of climate variables and temperature modeling

    Science.gov (United States)

    Samanta, Sailesh; Pal, Dilip Kumar; Lohar, Debasish; Pal, Babita

    2012-01-01

    Geographic Information Systems (GIS) and modeling are becoming powerful tools in agricultural research and natural resource management. This study proposes an empirical methodology for modeling and mapping of the monthly and annual air temperature using remote sensing and GIS techniques. The study area is Gangetic West Bengal and its neighborhood in the eastern India, where a number of weather systems occur throughout the year. Gangetic West Bengal is a region of strong heterogeneous surface with several weather disturbances. This paper also examines statistical approaches for interpolating climatic data over large regions, providing different interpolation techniques for climate variables' use in agricultural research. Three interpolation approaches, like inverse distance weighted averaging, thin-plate smoothing splines, and co-kriging are evaluated for 4° × 4° area, covering the eastern part of India. The land use/land cover, soil texture, and digital elevation model are used as the independent variables for temperature modeling. Multiple regression analysis with standard method is used to add dependent variables into regression equation. Prediction of mean temperature for monsoon season is better than winter season. Finally standard deviation errors are evaluated after comparing the predicted temperature and observed temperature of the area. For better improvement, distance from the coastline and seasonal wind pattern are stressed to be included as independent variables.

  20. Gardening with Greenhouses

    Science.gov (United States)

    Keeler, Rusty

    2010-01-01

    Greenhouses come in all shapes, sizes, and price ranges: from simple hand-built plastic-covered frames to dazzling geodesic domes. Some child care centers install greenhouses as a part of their outdoor garden space. Other centers have incorporated a greenhouse into the building itself. Greenhouses provide a great opportunity for children to grow…

  1. Towards a model-based inventory of soil organic carbon in agricultural soils for the Swiss greenhouse gas reporting

    Science.gov (United States)

    Staudt, K.; Leifeld, J.; Bretscher, D.; Fuhrer, J.

    2012-04-01

    The Swiss inventory submission under the United Nations Framework Convention on Climate Change (UNFCCC) reports on changes in soil organic carbon stocks under different land-uses and land-use changes. The approach currently employed for cropland and grassland soils combines Tier 1 and Tier 2 methods and is considered overly simplistic. As the UNFCC encourages countries to develop Tier 3 methods for national greenhouse gas reporting, we aim to build up a model-based inventory of soil organic carbon in agricultural soils in Switzerland. We conducted a literature research on currently employed higher-tier methods using process-based models in four countries: Denmark, Sweden, Finland and the USA. The applied models stem from two major groups differing in complexity - those belonging to the group of general ecosystem models that include a plant-growth submodel, e.g. Century, and those that simulate soil organic matter turnover but not plant-growth, e.g. ICBM. For the latter group, carbon inputs to the soil from plant residues and roots have to be determined separately. We will present some aspects of the development of a model-based inventory of soil organic carbon in agricultural soils in Switzerland. Criteria for model evaluation are, among others, modeled land-use classes and land-use changes, spatial and temporal resolution, and coverage of relevant processes. For model parameterization and model evaluation at the field scale, data from several long-term agricultural experiments and monitoring sites in Switzerland is available. A subsequent regional application of a model requires the preparation of regional input data for the whole country - among others spatio-temporal meteorological data, agricultural and soil data. Following the evaluation of possible models and of available data, preference for application in the Swiss inventory will be given to simpler model structures, i.e. models without a plant-growth module. Thus, we compared different allometric relations

  2. High temperature furnace modeling and performance verifications

    Science.gov (United States)

    Smith, James E., Jr.

    1992-01-01

    Analytical, numerical, and experimental studies were performed on two classes of high temperature materials processing sources for their potential use as directional solidification furnaces. The research concentrated on a commercially available high temperature furnace using a zirconia ceramic tube as the heating element and an Arc Furnace based on a tube welder. The first objective was to assemble the zirconia furnace and construct parts needed to successfully perform experiments. The 2nd objective was to evaluate the zirconia furnace performance as a directional solidification furnace element. The 3rd objective was to establish a data base on materials used in the furnace construction, with particular emphasis on emissivities, transmissivities, and absorptivities as functions of wavelength and temperature. A 1-D and 2-D spectral radiation heat transfer model was developed for comparison with standard modeling techniques, and were used to predict wall and crucible temperatures. The 4th objective addressed the development of a SINDA model for the Arc Furnace and was used to design sample holders and to estimate cooling media temperatures for the steady state operation of the furnace. And, the 5th objective addressed the initial performance evaluation of the Arc Furnace and associated equipment for directional solidification. Results of these objectives are presented.

  3. Model analysis of energy consumption and greenhouse gas emissions of sewage sludge treatment systems with different processes and scales.

    Science.gov (United States)

    Soda, S; Iwai, Y; Sei, K; Shimod, Y; Ike, M

    2010-01-01

    An energy consumption model was developed for evaluating sewage sludge treatment plants (SSTPs) incorporating various treatment processes such as thickening, anaerobic digestion, dewatering, incineration, and melting. Based on data analyses from SSTPs in Osaka, Japan, electricity consumption intensities for thickening, anaerobic digestion, dewatering, incineration, and melting and heat consumption intensities for anaerobic digestion, incineration, and melting were expressed as functions of sludge-loading on each unit process. The model was applied for predicting the energy consumption and greenhouse gas (GHG) emissions of SSTPs using various treatment processes and power and heat generation processes using digestion gas. Results showed that SSTPs lacking incineration and melting processes but having power generation processes showed excess energy production at the high sludge-loading rate. Energy consumption of the SSTPs without incineration and melting processes were low, but their GHG emissions were high because of CH(4) and N(2)O emissions from sludge cake at the landfill site. Incineration and melting processes consume much energy, but have lower CH(4) and N(2)O emissions.

  4. GHGfrack: An Open-Source Model for Estimating Greenhouse Gas Emissions from Combustion of Fuel during Drilling and Hydraulic Fracturing.

    Science.gov (United States)

    Vafi, Kourosh; Brandt, Adam

    2016-07-19

    This paper introduces GHGfrack, an open-source engineering-based model that estimates energy consumption and associated GHG emissions from drilling and hydraulic fracturing operations. We describe verification and calibration of GHGfrack against field data for energy and fuel consumption. We run GHGfrack using data from 6927 wells in Eagle Ford and 4431 wells in Bakken oil fields. The average estimated energy consumption in Eagle Ford wells using lateral hole diameters of 8 (3)/4 and 6 (1)/8 in. are 2.25 and 2.73 TJ/well, respectively. The average estimated energy consumption in Bakken wells using hole diameters of 6 in. for horizontal section is 2.16 TJ/well. We estimate average greenhouse gas (GHG) emissions of 419 and 510 tonne of equivalent CO2 per well (tonne of CO2 eq/well) for the two aforementioned assumed geometries in Eagle Ford, respectively, and 417 tonne of CO2 eq/well for the case of Bakken. These estimates are limited only to GHG emissions from combustion of diesel fuel to supply energy only for rotation of drill string, drilling mud circulation, and fracturing pumps. Sensitivity analysis of the model shows that the top three key variables in driving energy intensity in drilling are the lateral hole diameter, drill pipe internal diameter, and mud flow rate. In hydraulic fracturing, the top three are lateral casing diameter, fracturing fluid volume, and length of the lateral.

  5. Uncertainties in the attribution of greenhouse gas warming and implications for climate prediction

    CERN Document Server

    Jones, Gareth S; Mitchell, John F B

    2016-01-01

    Using optimal detection techniques with climate model simulations, most of the observed increase of near surface temperatures over the second half of the twentieth century is attributed to anthropogenic influences. However, the partitioning of the anthropogenic influence to individual factors, such as greenhouse gases and aerosols, is much less robust. Differences in how forcing factors are applied, in their radiative influence and in models' climate sensitivities, substantially influence the response patterns. We find standard optimal detection methodologies cannot fully reconcile this response diversity. By selecting a set of experiments to enable the diagnosing of greenhouse gases and the combined influence of other anthropogenic and natural factors, we find robust detections of well mixed greenhouse gases across a large ensemble of models. Of the observed warming over the 20th century of 0.65K/century we find, using a multi model mean not incorporating pattern uncertainty, a well mixed greenhouse gas warm...

  6. Complex-temperature singularities of Ising models

    CERN Document Server

    Shrock, R E

    1995-01-01

    We report new results on complex-temperature properties of Ising models. These include studies of the s=1/2 model on triangular, honeycomb, kagom\\'e, 3 \\cdot 12^2, and 4 \\cdot 8^2 lattices. We elucidate the complex--T phase diagrams of the higher-spin 2D Ising models, using calculations of partition function zeros. Finally, we investigate the 2D Ising model in an external magnetic field, mapping the complex--T phase diagram and exploring various singularities therein. For the case \\beta H=i\\pi/2, we give exact results on the phase diagram and obtain susceptibility exponents \\gamma' at various singularities from low-temperature series analyses.

  7. Model requirements for estimating and reporting soil C stock changes in national greenhouse gas inventories

    Science.gov (United States)

    Didion, Markus; Blujdea, Viorel; Grassi, Giacomo; Hernández, Laura; Jandl, Robert; Kriiska, Kaie; Lehtonen, Aleksi; Saint-André, Laurent

    2016-04-01

    Globally, soils are the largest terrestrial store of carbon (C) and small changes may contribute significantly to the global C balance. Due to the potential implications for climate change, accurate and consistent estimates of C fluxes at the large-scale are important as recognized, for example, in international agreements such as the United Nations Framework Convention on Climate Change (UNFCCC). Under the UNFCCC and also under the Kyoto Protocol it is required to report C balances annually. Most measurement-based soil inventories are currently not able to detect annual changes in soil C stocks consistently across space and representative at national scales. The use of models to obtain relevant estimates is considered an appropriate alternative under the UNFCCC and the Kyoto Protocol. Several soil carbon models have been developed but few models are suitable for a consistent application across larger-scales. Consistency is often limited by the lack of input data for models, which can result in biased estimates and, thus, the reporting criteria of accuracy (i.e., emission and removal estimates are systematically neither over nor under true emissions or removals) may be met. Based on a qualitative assessment of the ability to meet criteria established for GHG reporting under the UNFCCC including accuracy, consistency, comparability, completeness, and transparency, we identified the suitability of commonly used simulation models for estimating annual C stock changes in mineral soil in European forests. Among six discussed simulation models we found a clear trend toward models for providing quantitative precise site-specific estimates which may lead to biased estimates across space. To meet reporting needs for national GHG inventories, we conclude that there is a need for models producing qualitative realistic results in a transparent and comparable manner. Based on the application of one model along a gradient from Boreal forests in Finland to Mediterranean forests

  8. Numerical Simulation of Global Temperature Change during the 20th Century with the IAP/LASG GOALS Model

    Institute of Scientific and Technical Information of China (English)

    马晓燕; 郭裕福; 石广玉; 俞永强

    2004-01-01

    The IAP/LASG GOALS coupled model is used to simulate the climate change during the 20th century using historical greenhouse gases concentrations, the mass mixing ratio of sulfate aerosols simulated by a CTM model, and reconstruction of solar variability spanning the period 1900 to 1997. Four simulations,including a control simulation and three forcing simulations, are conducted. Comparison with the observational record for the period indicates that the three forcing experiments simulate reasonable temporal and spatial distributions of the temperature change. The global warming during the 20th century is caused mainly by increasing greenhouse gas concentration especially since the late 1980s; sulfate aerosols offset a portion of the global warming and the reduction of global temperature is up to about 0.11°C over the century; additionally, the effect of solar variability is not negligible in the simulation of climate change over the 20th century.

  9. Nonlinear response of modelled stratospheric ozone to changes in greenhouse gases and ozone depleting substances in the recent past

    National Research Council Canada - National Science Library

    S Meul; S Oberländer -Hayn; J Abalichin; U Langematz

    2015-01-01

    ...) and greenhouse gases (GHGs). The impact of the single forcings on O3 is well known. Interactions between the simultaneously increased GHG and ODS concentrations, however, can occur and lead to nonlinear O3 changes...

  10. Enhanced battery model including temperature effects

    NARCIS (Netherlands)

    Rosca, B.; Wilkins, S.

    2013-01-01

    Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a dy

  11. Enhanced battery model including temperature effects

    NARCIS (Netherlands)

    Rosca, B.; Wilkins, S.

    2013-01-01

    Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a dy

  12. Enhanced battery model including temperature effects

    NARCIS (Netherlands)

    Rosca, B.; Wilkins, S.

    2013-01-01

    Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a

  13. Utilizing patch and site level greenhouse-gas concentration measurements in tandem with the prognostic model, ecosys

    Science.gov (United States)

    Morin, T. H.; Rey Sanchez, C.; Bohrer, G.; Riley, W. J.; Angle, J.; Mekonnen, Z. A.; Stefanik, K. C.; Wrighton, K. C.

    2016-12-01

    Estimates of wetland greenhouse gas (GHG) budgets currently have large uncertainties. While wetlands are the largest source of natural methane (CH4) emissions worldwide, they are also important carbon dioxide (CO2) sinks. Determining the GHG budget of a wetland is challenging, particularly because wetlands have intrinsically temporally and spatially heterogeneous land cover patterns and complex dynamics of CH4 production and emissions. These issues pose challenges to both measuring and modeling GHG budgets from wetlands. To improve wetland GHG flux predictability, we utilized the ecosys model to predict CH4 fluxes from a natural temperate estuarine wetland in northern Ohio. Multiple patches of terrain (that included Typha spp. and Nelumbo lutea) were represented as separate grid cells in the model. Cells were initialized with measured values but were allowed to dynamically evolve in response to meteorological, hydrological, and thermodynamic conditions. Trace gas surface emissions were predicted as the end result of microbial activity, physical transport, and plant processes. Corresponding to each model gridcell, measurements of dissolved gas concentrations were conducted with pore-water dialysis samplers (peepers). The peeper measurements were taken via a series of tubes, providing an undisturbed observation of the pore water concentrations of in situ dissolved gases along a vertical gradient. Non-steady state chambers and a flux tower provided both patch level and integrated site-level fluxes of CO2 and CH4. New Typha chambers were also developed to enclose entire plants and segregate the plant fluxes from soil/water fluxes. We expect ecosys to predict the seasonal and diurnal fluxes of CH4 from within each land cover type and to resolve where CH4 is generated within the soil column and its transmission mechanisms. We demonstrate the need for detailed information at both the patch and site level when using models to predict whole wetland ecosystem-scale GHG

  14. An energy balance perspective on regional CO2-induced temperature changes in CMIP5 models

    Science.gov (United States)

    Räisänen, Jouni

    2016-08-01

    An energy balance decomposition of temperature changes is conducted for idealized transient CO2-only simulations in the fifth phase of the Coupled Model Intercomparison Project. The multimodel global mean warming is dominated by enhanced clear-sky greenhouse effect due to increased CO2 and water vapour, but other components of the energy balance substantially modify the geographical and seasonal patterns of the change. Changes in the net surface energy flux are important over the oceans, being especially crucial for the muted warming over the northern North Atlantic and for the seasonal cycle of warming over the Arctic Ocean. Changes in atmospheric energy flux convergence tend to smooth the gradients of temperature change and reduce its land-sea contrast, but they also amplify the seasonal cycle of warming in northern North America and Eurasia. The three most important terms for intermodel differences in warming are the changes in the clear-sky greenhouse effect, clouds, and the net surface energy flux, making the largest contribution to the standard deviation of annual mean temperature change in 34, 29 and 20 % of the world, respectively. Changes in atmospheric energy flux convergence mostly damp intermodel variations of temperature change especially over the oceans. However, the opposite is true for example in Greenland and Antarctica, where the warming appears to be substantially controlled by heat transport from the surrounding sea areas.

  15. An energy balance perspective on regional CO2-induced temperature changes in CMIP5 models

    Science.gov (United States)

    Räisänen, Jouni

    2017-05-01

    An energy balance decomposition of temperature changes is conducted for idealized transient CO2-only simulations in the fifth phase of the Coupled Model Intercomparison Project. The multimodel global mean warming is dominated by enhanced clear-sky greenhouse effect due to increased CO2 and water vapour, but other components of the energy balance substantially modify the geographical and seasonal patterns of the change. Changes in the net surface energy flux are important over the oceans, being especially crucial for the muted warming over the northern North Atlantic and for the seasonal cycle of warming over the Arctic Ocean. Changes in atmospheric energy flux convergence tend to smooth the gradients of temperature change and reduce its land-sea contrast, but they also amplify the seasonal cycle of warming in northern North America and Eurasia. The three most important terms for intermodel differences in warming are the changes in the clear-sky greenhouse effect, clouds, and the net surface energy flux, making the largest contribution to the standard deviation of annual mean temperature change in 34, 29 and 20 % of the world, respectively. Changes in atmospheric energy flux convergence mostly damp intermodel variations of temperature change especially over the oceans. However, the opposite is true for example in Greenland and Antarctica, where the warming appears to be substantially controlled by heat transport from the surrounding sea areas.

  16. Irrigation management in organic greenhouse

    NARCIS (Netherlands)

    Voogt, W.; Balendonck, J.; Berkelmans, R.; Enthoven, N.

    2017-01-01

    Irrigation in protected cultivation is essential due to the absence of natural precipitation. High evapotranspiration, due to higher temperature and prolonged cropping period, requires ample an adequate supply of water. The water supply in a greenhouse is solely carried out by irrigation and thus

  17. The effect of greenhouse gas concentrations and ice sheets on the glacial AMOC in a coupled climate model

    Science.gov (United States)

    Klockmann, Marlene; Mikolajewicz, Uwe; Marotzke, Jochem

    2016-09-01

    Simulations with the Max Planck Institute Earth System Model (MPI-ESM) are used to study the sensitivity of the AMOC and the deep-ocean water masses during the Last Glacial Maximum to different sets of forcings. Analysing the individual contributions of the glacial forcings reveals that the ice sheets cause an increase in the overturning strength and a deepening of the North Atlantic Deep Water (NADW) cell, while the low greenhouse gas (GHG) concentrations cause a decrease in overturning strength and a shoaling of the NADW cell. The effect of the orbital configuration is negligible. The effects of the ice sheets and the GHG reduction balance each other in the deep ocean so that no shoaling of the NADW cell is simulated in the full glacial state. Experiments in which different GHG concentrations with linearly decreasing radiative forcing are applied to a setup with glacial ice sheets and orbital configuration show that GHG concentrations below the glacial level are necessary to cause a shoaling of the NADW cell with respect to the pre-industrial state in MPI-ESM. For a pCO2 of 149 ppm, the simulated overturning state and the deep-ocean water masses are in best agreement with the glacial state inferred from proxy data. Sensitivity studies confirm that brine release and shelf convection in the Southern Ocean are key processes for the shoaling of the NADW cell. Shoaling occurs only when Southern Ocean shelf water contributes significantly to the formation of Antarctic Bottom Water.

  18. Meth math: modeling temperature responses to methamphetamine.

    Science.gov (United States)

    Molkov, Yaroslav I; Zaretskaia, Maria V; Zaretsky, Dmitry V

    2014-04-15

    Methamphetamine (Meth) can evoke extreme hyperthermia, which correlates with neurotoxicity and death in laboratory animals and humans. The objective of this study was to uncover the mechanisms of a complex dose dependence of temperature responses to Meth by mathematical modeling of the neuronal circuitry. On the basis of previous studies, we composed an artificial neural network with the core comprising three sequentially connected nodes: excitatory, medullary, and sympathetic preganglionic neuronal (SPN). Meth directly stimulated the excitatory node, an inhibitory drive targeted the medullary node, and, in high doses, an additional excitatory drive affected the SPN node. All model parameters (weights of connections, sensitivities, and time constants) were subject to fitting experimental time series of temperature responses to 1, 3, 5, and 10 mg/kg Meth. Modeling suggested that the temperature response to the lowest dose of Meth, which caused an immediate and short hyperthermia, involves neuronal excitation at a supramedullary level. The delay in response after the intermediate doses of Meth is a result of neuronal inhibition at the medullary level. Finally, the rapid and robust increase in body temperature induced by the highest dose of Meth involves activation of high-dose excitatory drive. The impairment in the inhibitory mechanism can provoke a life-threatening temperature rise and makes it a plausible cause of fatal hyperthermia in Meth users. We expect that studying putative neuronal sites of Meth action and the neuromediators involved in a detailed model of this system may lead to more effective strategies for prevention and treatment of hyperthermia induced by amphetamine-like stimulants.

  19. Betting strategies on fluctuations in the transient response of greenhouse warming.

    Science.gov (United States)

    Risbey, James S; Lewandowsky, Stephan; Hunter, John R; Monselesan, Didier P

    2015-11-28

    We examine a series of betting strategies on the transient response of greenhouse warming, expressed by changes in 15-year mean global surface temperature from one 15-year period to the next. Over the last century, these bets are increasingly dominated by positive changes (warming), reflecting increasing greenhouse forcing and its rising contribution to temperature changes on this time scale. The greenhouse contribution to 15-year trends is now of a similar magnitude to typical naturally occurring 15-year trends. Negative 15-year changes (decreases) have not occurred since about 1970, and are still possible, but now rely on large, and therefore infrequent, natural variations. Model projections for even intermediate warming scenarios show very low likelihoods of obtaining negative 15-year changes over the coming century. Betting against greenhouse warming, even on these short time scales, is no longer a rational proposition.

  20. Modeling Future Life-Cycle Greenhouse Gas Emissions and Environmental Impacts of Electricity Supplies in Brazil

    OpenAIRE

    2013-01-01

    Brazil’s status as a rapidly developing country is visible in its need for more energy, including electricity. While the current electricity generation mix is primarily hydropower based, high-quality dam sites are diminishing and diversification to other sources is likely. We combined life-cycle data for electricity production with scenarios developed using the IAEA’s MESSAGE model to examine environmental impacts of future electricity generation under a baseline case and four side cases, usi...

  1. Geothermal heating systems for greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.F.; Johnson, W.C.

    1980-08-12

    Ways to utilize low-temperature geothermally heated water for a flow-through system are presented. The geothermal energy used for this system is the waste heat discharged from space heating 500,000 square feet of floor space at Oregon Institute of Technology with geothermal water pumped directly from the campus wells. The information collected and analyzed is from data developed from operating a greenhouse on the Oregon Institute of Technology campus from December 1979 to April 1980. Methods for calculating heating requirements of greenhouses using geothermal energy were developed from the analyses of the data obtained. (MHR)

  2. Neural network modeling of energy use and greenhouse gas emissions of watermelon production systems

    Directory of Open Access Journals (Sweden)

    Ashkan Nabavi-Pelesaraei

    2016-01-01

    Full Text Available This study was conducted in order to determine energy consumption, model and analyze the input–output, energy efficiencies and GHG emissions for watermelon production using artificial neural networks (ANNs in the Guilan province of Iran, based on three different farm sizes. For this purpose, the initial data was collected from 120 watermelon producers in Langroud and Chaf region, two small cities in the Guilan province. The results indicated that total average energy input for watermelon production was 40228.98 MJ ha–1. Also, chemical fertilizers (with 76.49% were the highest energy inputs for watermelon production. Moreover, the share of non-renewable energy (with 96.24% was more than renewable energy (with 3.76% in watermelon production. The rate of energy use efficiency, energy productivity and net energy was calculated as 1.29, 0.68 kg MJ−1 and 11733.64 MJ ha−1, respectively. With respect to GHG analysis, the average of total GHG emissions was calculated about 1015 kgCO2eq. ha−1. The results illustrated that share of nitrogen (with 54.23% was the highest in GHG emissions for watermelon production, followed by diesel fuel (with 16.73% and electricity (with 15.45%. In this study, Levenberg–Marquardt learning Algorithm was used for training ANNs based on data collected from watermelon producers. The ANN model with 11–10–2 structure was the best one for predicting the watermelon yield and GHG emissions. In the best topology, the coefficient of determination (R2 was calculated as 0.969 and 0.995 for yield and GHG emissions of watermelon production, respectively. Furthermore, the results of sensitivity analysis revealed that the seed and human labor had the highest sensitivity in modeling of watermelon yield and GHG emissions, respectively.

  3. Modeling quantum fluid dynamics at nonzero temperatures

    Science.gov (United States)

    Berloff, Natalia G.; Brachet, Marc; Proukakis, Nick P.

    2014-03-01

    The detailed understanding of the intricate dynamics of quantum fluids, in particular in the rapidly growing subfield of quantum turbulence which elucidates the evolution of a vortex tangle in a superfluid, requires an in-depth understanding of the role of finite temperature in such systems. The Landau two-fluid model is the most successful hydrodynamical theory of superfluid helium, but by the nature of the scale separations it cannot give an adequate description of the processes involving vortex dynamics and interactions. In our contribution we introduce a framework based on a nonlinear classical-field equation that is mathematically identical to the Landau model and provides a mechanism for severing and coalescence of vortex lines, so that the questions related to the behavior of quantized vortices can be addressed self-consistently. The correct equation of state as well as nonlocality of interactions that leads to the existence of the roton minimum can also be introduced in such description. We review and apply the ideas developed for finite-temperature description of weakly interacting Bose gases as possible extensions and numerical refinements of the proposed method. We apply this method to elucidate the behavior of the vortices during expansion and contraction following the change in applied pressure. We show that at low temperatures, during the contraction of the vortex core as the negative pressure grows back to positive values, the vortex line density grows through a mechanism of vortex multiplication. This mechanism is suppressed at high temperatures.

  4. Modeling Low-temperature Geochemical Processes

    Science.gov (United States)

    Nordstrom, D. K.

    2003-12-01

    Geochemical modeling has become a popular and useful tool for a wide number of applications from research on the fundamental processes of water-rock interactions to regulatory requirements and decisions regarding permits for industrial and hazardous wastes. In low-temperature environments, generally thought of as those in the temperature range of 0-100 °C and close to atmospheric pressure (1 atm=1.01325 bar=101,325 Pa), complex hydrobiogeochemical reactions participate in an array of interconnected processes that affect us, and that, in turn, we affect. Understanding these complex processes often requires tools that are sufficiently sophisticated to portray multicomponent, multiphase chemical reactions yet transparent enough to reveal the main driving forces. Geochemical models are such tools. The major processes that they are required to model include mineral dissolution and precipitation; aqueous inorganic speciation and complexation; solute adsorption and desorption; ion exchange; oxidation-reduction; or redox; transformations; gas uptake or production; organic matter speciation and complexation; evaporation; dilution; water mixing; reaction during fluid flow; reaction involving biotic interactions; and photoreaction. These processes occur in rain, snow, fog, dry atmosphere, soils, bedrock weathering, streams, rivers, lakes, groundwaters, estuaries, brines, and diagenetic environments. Geochemical modeling attempts to understand the redistribution of elements and compounds, through anthropogenic and natural means, for a large range of scale from nanometer to global. "Aqueous geochemistry" and "environmental geochemistry" are often used interchangeably with "low-temperature geochemistry" to emphasize hydrologic or environmental objectives.Recognition of the strategy or philosophy behind the use of geochemical modeling is not often discussed or explicitly described. Plummer (1984, 1992) and Parkhurst and Plummer (1993) compare and contrast two approaches for

  5. A sub-circuit MOSFET model with a wide temperature range including cryogenic temperature*

    Institute of Scientific and Technical Information of China (English)

    Jia Kan; Sun Weifeng; Shi Longxing

    2011-01-01

    A sub-circuit SPICE model ofa MOSFET for low temperature operation is presented. Two resistors are introduced for the freeze-out effect, and the explicit behavioral models are developed for them. The model can be used in a wide temperature range covering both cryogenic temperature and regular temperatures.

  6. Estimating the greenhouse gas fluxes of European grasslands with a process-based model: 1. Model evaluation from in situ measurements

    Science.gov (United States)

    Vuichard, Nicolas; Soussana, Jean-FrançOis; Ciais, Philippe; Viovy, Nicolas; Ammann, Christof; Calanca, Pierluigi; Clifton-Brown, John; Fuhrer, Jürg; Jones, Mike; Martin, CéCile

    2007-03-01

    We improved a process-oriented biogeochemical model of carbon and nitrogen cycling in grasslands and tested it against in situ measurements of biomass and CO2 and CH4 fluxes at five European grassland sites. The new version of the model (PASIM) calculates the growth and senescence of aboveground vegetation biomass accounting for sporadic removals when the grassland is cut and for continuous removals when it is grazed. Limitations induced by high leaf area index (LAI), soil water deficits and aging of leaves are also included. We added to this a simple empirical formulation to account for the detrimental impact on vegetation of trampling and excreta by grazing animals. Finally, a more realistic methane emission module than is currently used was introduced on the basis of the quality of the animals' diet. Evaluation of this improved version of PASIM is performed at (1) Laqueuille, France, on grassland continuously grazed by cattle with two plots of intensive and extensive grazing intensities, (2) Oensingen, Switzerland, on cut grassland with two fertilized and nonfertilized plots, and (3) Carlow, Ireland, on grassland that is both cut and grazed by cattle during the growing season. In addition, we compared the modeled animal CH4 emissions with in situ measurements on cattle for two grazing intensities at the grazed grassland site of Laqueuille. Altogether, when all improvements to the PASIM model are included, we found that the new parameterizations resulted into a better fit to the observed seasonal cycle of biomass and of measured CO2 and CH4 fluxes. However, the large uncertainties in measurements of biomass and LAI make simulation of biomass dynamics difficult to make. Also simulations for cut grassland are better than for grazed swards. This work paves the way for simulating greenhouse gas fluxes over grasslands in a spatially explicit manner, in order to quantify and understand the past, present and future role of grasslands in the greenhouse gas budget of the

  7. Modeling Future Life-Cycle Greenhouse Gas Emissions and Environmental Impacts of Electricity Supplies in Brazil

    Directory of Open Access Journals (Sweden)

    Melissa M. Bilec

    2013-07-01

    Full Text Available Brazil’s status as a rapidly developing country is visible in its need for more energy, including electricity. While the current electricity generation mix is primarily hydropower based, high-quality dam sites are diminishing and diversification to other sources is likely. We combined life-cycle data for electricity production with scenarios developed using the IAEA’s MESSAGE model to examine environmental impacts of future electricity generation under a baseline case and four side cases, using a Monte-Carlo approach to incorporate uncertainty in power plant performance and LCA impacts. Our results show that, under the cost-optimal base case scenario, Brazil’s GHGs from electricity (excluding hydroelectric reservoir emissions rise 370% by 2040 relative to 2010, with the carbon intensity per MWh rising 100%. This rise would make Brazil’s carbon emissions targets difficult to meet without demand-side programs. Our results show a future electricity mix dominated by environmental tradeoffs in the use of large-scale renewables, questioning the use tropical hydropower and highlighting the need for additional work to assess and include ecosystem and social impacts, where information is currently sparse.

  8. Agriculture: Nurseries and Greenhouses

    Science.gov (United States)

    Nurseries and Greenhouses. Information about environmental requirements specifically relating to the production of many types of agricultural crops grown in nurseries and greenhouses, such as ornamental plants and specialty fruits and vegetables.

  9. 21st Century Trends in Antarctic Temperature and Polar Stratospheric Cloud (PSC) Area in the GEOS Chemistry-Climate Model

    Science.gov (United States)

    Hurwitz, M. M.; Newman, P. A.

    2010-01-01

    This study examines trends in Antarctic temperature and APSC, a temperature proxy for the area of polar stratospheric clouds, in an ensemble of Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) simulations of the 21st century. A selection of greenhouse gas, ozone-depleting substance, and sea surface temperature scenarios is used to test the trend sensitivity to these parameters. One scenario is used to compare temperature trends in two versions of the GEOS CCM. An extended austral winter season is examined in detail. In May, June, and July, the expected future increase in CO2-related radiative cooling drives temperature trends in the Antarctic lower stratosphere. At 50 hPa, a 1.3 K cooling is expected between 2000 and 2100. Ozone levels increase, despite this robust cooling signal and the consequent increase in APSC, suggesting the enhancement of stratospheric transport in future. In the lower stratosphere, the choice of climate change scenarios does not affect the magnitude of the early winter cooling. Midwinter temperature trends are generally small. In October, APSC trends have the same sign as the prescribed halogen trends. That is, there are negative APSC trends in "grealistic future" simulations, where halogen loading decreases in accordance with the Montreal Protocol and CO2 continues to increase. In these simulations, the speed of ozone recovery is not influenced by either the choice of sea surface temperature and greenhouse gas scenarios or by the model version.

  10. Growing different Lactuca genotypes aeroponically within a tropical greenhouse – Cool rootzone temperatures decreased rootzone ethylene concentrations and increased shoot growth

    Directory of Open Access Journals (Sweden)

    Tsui Wei CHOONG

    2016-09-01

    Full Text Available Temperate crops cannot grow well in the tropics without rootzone cooling. As cooling increased production costs, this experiment aimed to study the growth of various Lactuca genotypes and propose possible ways of reducing these costs, without compromising productivity. A recombinant inbred line (RIL of lettuce and its parental lines (L. serriola and L. sativa ‘Salinas’ were grown aeroponically in a tropical greenhouse under 24 C cool (C or warm fluctuating 30-36 C ambient (A rootzone temperature (RZT. Their roots were misted with Netherlands standard nutrient solution for 1 min, at intervals of either 5 min (A5, C5 or 10 min (A10, C10 in attempting to reduce electricity consumption and production costs. Lower mortality and higher productivity were observed in all genotypes when grown in C-RZT. Higher shoot fresh weight was observed under C5 than C10, for the RIL and L. serriola. Since ‘Salinas’ had similar shoot fresh weight at both C-RZ treatments, this may indicate it is more sensitive to RZT than water availability. Under A-RZ treatments, higher carotenoid content, with correspondingly higher nonphotochemical quenching, was observed in A10 for the RIL and ‘Salinas’. Further, total chlorophyll content was also highest at this RZ treatment for the RIL though photochemical quenching was contrastingly the lowest. Cumulatively, productivity was compromised at A10 as the RIL seemed to prioritize photoprotection over efficiency in photosynthesis, under conditions of higher RZT and lower water availability. Generally, higher RZ ethylene concentrations accumulated in A10 and C10 than A5 and C5, respectively – probably due to spray frequency exerting a greater effect on RZ ethylene accumulation than RZT. In the C5 RZ treatment, lowest RZ ethylene concentration corresponded with highest shoot fresh weight. As such, further research on ethylene (insensitivity and water use efficiency could be conducted to identify Lactuca cultivars

  11. Growing Different Lactuca Genotypes Aeroponically within a Tropical Greenhouse-Cool Rootzone Temperatures Decreased Rootzone Ethylene Concentrations and Increased Shoot Growth.

    Science.gov (United States)

    Choong, Tsui-Wei; He, Jie; Lee, Sing K; Dodd, Ian C

    2016-01-01

    Temperate crops cannot grow well in the tropics without rootzone cooling. As cooling increased production costs, this experiment aimed to study the growth of various Lactuca genotypes and propose possible ways of reducing these costs, without compromising productivity. A recombinant inbred line (RIL) of lettuce and its parental lines (L. serriola and L. sativa "Salinas") were grown aeroponically in a tropical greenhouse under 24°C cool (C) or warm fluctuating 30-36°C ambient (A) rootzone temperature (RZT). Their roots were misted with Netherlands standard nutrient solution for 1 min, at intervals of either 5 min (A5, C5) or 10 min (A10, C10) in attempting to reduce electricity consumption and production costs. Lower mortality and higher productivity were observed in all genotypes when grown in C-RZT. Higher shoot fresh weight was observed under C5 than C10, for the RIL and L. serriola. Since "Salinas" had similar shoot fresh weight at both C-RZ treatments, this may indicate it is more sensitive to RZT than water availability. Under A-RZ treatments, higher carotenoid content, with correspondingly higher nonphotochemical quenching, was observed in A10 for the RIL and "Salinas." Further, total chlorophyll content was also highest at this RZ treatment for the RIL though photochemical quenching was contrastingly the lowest. Cumulatively, productivity was compromised at A10 as the RIL seemed to prioritize photoprotection over efficiency in photosynthesis, under conditions of higher RZT and lower water availability. Generally, higher RZ ethylene concentrations accumulated in A10 and C10 than A5 and C5, respectively-probably due to spray frequency exerting a greater effect on RZ ethylene accumulation than RZT. In the C5 RZ treatment, lowest RZ ethylene concentration corresponded with highest shoot fresh weight. As such, further research on ethylene (in)sensitivity and water use efficiency could be conducted to identify Lactuca cultivars that are better suited for growth

  12. Dynamic assessment of air temperature for tomato (Lycopersicon esculentum mill) cultivation in a naturally ventilated net-screen greenhouse under tropical lowlands climate

    NARCIS (Netherlands)

    Shamshiri, R.; Beveren, van P.; Che Man, H.; Zakaria, A.J.

    2017-01-01

    Net-screen covered greenhouses operating on natural ventilation are used as a sustainable approach for closed-field cultivation of fruits and vegetables and to eliminate insect passage and the subsequent production damage. The objective of this work was to develop a real-time assessment framework fo

  13. Temperature influences in receiver clock modelling

    Science.gov (United States)

    Wang, Kan; Meindl, Michael; Rothacher, Markus; Schoenemann, Erik; Enderle, Werner

    2016-04-01

    In Precise Point Positioning (PPP), hardware delays at the receiver site (receiver, cables, antenna, …) are always difficult to be separated from the estimated receiver clock parameters. As a result, they are partially or fully contained in the estimated "apparent" clocks and will influence the deterministic and stochastic modelling of the receiver clock behaviour. In this contribution, using three years of data, the receiver clock corrections of a set of high-precision Hydrogen Masers (H-Masers) connected to stations of the ESA/ESOC network and the International GNSS Service (IGS) are firstly characterized concerning clock offsets, drifts, modified Allan deviations and stochastic parameters. In a second step, the apparent behaviour of the clocks is modelled with the help of a low-order polynomial and a known temperature coefficient (Weinbach, 2013). The correlations between the temperature and the hardware delays generated by different types of antennae are then analysed looking at daily, 3-day and weekly time intervals. The outcome of these analyses is crucial, if we intend to model the receiver clocks in the ground station network to improve the estimation of station-related parameters like coordinates, troposphere zenith delays and ambiguities. References: Weinbach, U. (2013) Feasibility and impact of receiver clock modeling in precise GPS data analysis. Dissertation, Leibniz Universität Hannover, Germany.

  14. Impact of greenhouse gases on the Earth's ozone layer

    Science.gov (United States)

    Zadorozhny, Alexander

    A numerical 2-D zonally averaged interactive dynamical radiative-photochemical model of the ozonosphere including aerosol physics is used to examine the role of the greenhouse gases CO2 , CH4 , and N2 O in the future long-term changes of the Earth's ozone layer, in particular in its recovery after reduction of anthropogenic discharges of chlorine and bromine compounds into the atmosphere. The model allows calculating self-consistently diabatic circulation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the South to North Poles, as well as distribution of sulphate aerosol particles and polar stratospheric clouds (PSCs) of types I and II. The scenarios of expected changes of the anthropogenic pollutants for the period from 1980 through 2050 are taken from Climate Change 2001. The processes, which determine the influence of anthropogenic growth of atmospheric abundance of the greenhouse gases on the dynamics of recovery of the Earth's ozone layer, have been studied in details. Expected cooling of the stratosphere caused by increases of greenhouse gases, most importantly CO2 , essentially influences the ozone layer by two ways: through temperature dependencies of the gas phase reaction rates and through enhancement of polar ozone depletion via increased PSC formation. The model calculations show that a weakness in efficiencies of all gas phase catalytic cycles of the ozone destruction due to cooling of the stratosphere is a dominant mechanism of the impact of the greenhouse gases on the ozone layer in Antarctic as well as at the lower latitudes. This mechanism leads to a significant acceleration of the ozone layer recovery here because of the greenhouse gases growth. On the contrary, the mechanism of the impact of the greenhouse gases on the ozone through PSC modification begins to be more effective in Arctic in comparison with the gas phase mechanism in springs after about 2020, which leads to retard the expected recovery of the

  15. The Dynamic Greenhouse Challenge

    Science.gov (United States)

    Roman, Harry T.

    2010-01-01

    Greenhouses are marvelous devices, allowing one to enjoy the flower spectacle of summer all year round. At night, greenhouses use supplemental heat to keep the fragile plants warm. Over the last 30 years, greenhouse technology has undergone many changes, with the structures being automated and monitored and low-cost plastic structures emerging as…

  16. Changes in net ecosystem productivity and greenhouse gas exchange with fertilization of Douglas fir: Mathematical modeling in ecosys

    Science.gov (United States)

    Grant, R. F.; Black, T. A.; Jassal, R. S.; Bruemmer, C.

    2010-12-01

    The application of nitrogen fertilizers to Douglas fir forests is known to raise net ecosystem productivity (NEP), but also N2O emissions, the CO2 equivalent of which may offset gains in NEP when accounting for net greenhouse gas (GHG) exchange. However, total changes in NEP and N2O emissions caused by fertilizer between times of application and harvest, while needed for national GHG inventories, are difficult to quantify except through modeling. In this study, integrated hypotheses for soil and plant N processes within the ecosystem model ecosys were tested against changes in CO2 and N2O fluxes recorded with eddy covariance (EC) and surface flux chambers for 1 year after applying 20 g N m-2 of urea to a mature Douglas fir stand in British Columbia. Parameters from annual regressions of hourly modeled versus measured CO2 fluxes conducted before and after fertilization were unchanged (b = 1.0, R2 = 0.8, RMSD = 3.4 μmol m-2 s-1), indicating that model hypotheses for soil and plant N processes did not introduce bias into CO2 fluxes modeled after fertilization. These model hypotheses were then used to project changes in NEP and GHG exchange attributed to the fertilizer during the following 10 years until likely harvest of the Douglas fir stand. Increased CO2 uptake caused modeled and EC-derived annual NEP to rise from 443 and 386 g C m-2 in the year before fertilization to 591 and 547 g C m-2 in the year after. These gains contributed to a sustained rise in modeled wood C production with fertilization, which was partly offset by a decline in soil C attributed in the model to reduced root C productivity and litterfall. Gains in net CO2 uptake were further offset in the model by a rise of 0.74 g N m-2 yr-1 in N2O emissions during the first year after fertilization, which was consistent with one of 1.05 g N m-2 yr-1 estimated from surface flux chamber measurements. Further N2O emissions were neither modeled nor measured after the first year. At the end of the 11 year

  17. Integrated control algorithms for plant environment in greenhouse

    Science.gov (United States)

    Zhang, Kanyu; Deng, Lujuan; Gong, Youmin; Wang, Shengxue

    2003-09-01

    In this paper a survey of plant environment control in artificial greenhouse was put forward for discussing the future development. Firstly, plant environment control started with the closed loop control of air temperature in greenhouse. With the emergence of higher property computer, the adaptive control algorithm and system identification were integrated into the control system. As adaptation control is more depending on observation of variables by sensors and yet many variables are unobservable or difficult to observe, especially for observation of crop growth status, so model-based control algorithm were developed. In order to evade modeling difficulty, one method is predigesting the models and the other method is utilizing fuzzy logic and neural network technology that realize the models by the black box and gray box theory. Studies on control method of plant environment in greenhouse by means of expert system (ES) and artificial intelligence (AI) have been initiated and developed. Nowadays, the research of greenhouse environment control focus on energy saving, optimal economic profit, enviornment protection and continualy develop.

  18. Reversible and irreversible impacts of greenhouse gas emissions in multi-century projections with the NCAR global coupled carbon cycle-climate model

    Energy Technology Data Exchange (ETDEWEB)

    Froelicher, Thomas L.; Joos, Fortunat [University of Bern, Climate and Environmental Physics, Physics Institute, Bern (Switzerland); University of Bern, Oeschger Centre for Climate Change Research, Bern (Switzerland)

    2010-12-15

    The legacy of historical and the long-term impacts of 21st century greenhouse gas emissions on climate, ocean acidification, and carbon-climate feedbacks are investigated with a coupled carbon cycle-climate model. Emission commitment scenarios with zero emissions after year 2100 and 21st century emissions of 1,800, 900, and 0 gigatons of carbon are run up to year 2500. The reversibility and irreversibility of impacts is quantified by comparing anthropogenically-forced regional changes with internal, unforced climate variability. We show that the influence of historical emissions and of non-CO{sub 2} agents is largely reversible on the regional scale. Forced changes in surface temperature and precipitation become smaller than internal variability for most land and ocean grid cells in the absence of future carbon emissions. In contrast, continued carbon emissions over the 21st century cause irreversible climate change on centennial to millennial timescales in most regions and impacts related to ocean acidification and sea level rise continue to aggravate for centuries even if emissions are stopped in year 2100. Undersaturation of the Arctic surface ocean with respect to aragonite, a mineral form of calcium carbonate secreted by marine organisms, is imminent and remains widespread. The volume of supersaturated water providing habitat to calcifying organisms is reduced from preindustrial 40 to 25% in 2100 and to 10% in 2300 for the high emission case. We conclude that emission trading schemes, related to the Kyoto Process, should not permit trading between emissions of relatively short-lived agents and CO{sub 2} given the irreversible impacts of anthropogenic carbon emissions. (orig.)

  19. Energy Flexibility of The Commercial Greenhouse Growers

    DEFF Research Database (Denmark)

    Ma, Zheng; Jørgensen, Bo Nørregaard

    2016-01-01

    The commercial greenhouses can provide energy flexibility with the artificial lighting usage. Therefore, the commercial greenhouse growers can potentially play an important role in the electricity market as providers of flexibility services with the technology and software readiness. This paper...... takes Danish commercial growers and the Nordic regulating market as an example, to investigate the market potential with two business models. One business model is that commercial greenhouse growers directly participate in the regulating market. Another model is rescuing the BRPs’ (Balance Responsible...... Parties) imbalance error. Two calculations are formulated to evaluate the monetary benefits for the commercial greenhouse growers’ participation in both business models. The positive results indicate potential and benefits for the Danish commercial greenhouse growers’ participation in the electricity...

  20. Energy Flexibility of The Commercial Greenhouse Growers

    DEFF Research Database (Denmark)

    Ma, Zheng; Jørgensen, Bo Nørregaard

    2017-01-01

    The commercial greenhouses can provide energy flexibility with the artificial lighting usage. Therefore, the commercial greenhouse growers can potentially play an important role in the electricity market as providers of flexibility services with the technology and software readiness. This paper...... Parties) imbalance error. Two calculations are formulated to evaluate the monetary benefits for the commercial greenhouse growers’ participation in both business models. The positive results indicate potential and benefits for the Danish commercial greenhouse growers’ participation in the electricity...... takes Danish commercial growers and the Nordic regulating market as an example, to investigate the market potential with two business models. One business model is that commercial greenhouse growers directly participate in the regulating market. Another model is rescuing the BRPs’ (Balance Responsible...

  1. 日光温室土墙体温度变化及蓄热放热特点%Temperature variation, heat storage and heat release characteristics of soil wall in solar greenhouse

    Institute of Scientific and Technical Information of China (English)

    史宇亮; 王秀峰; 魏珉; 李清明; 刘福胜; 侯加林

    2016-01-01

    The solar greenhouse of soil wall, which has the advantages of good heat storage and low construction cost, is widely used in China. At present, the study on the heat storage and heat release performance of soil wall is an important hot spot, which can provide the theoretical basis for the simplification and thickness optimization of soil wall. In the paper, the sunken soil wall greenhouse serves as the research object in Taian, Shandong Province, China. The length is 50 m and the width is 10 m. The top and bottom thicknesses of the soil wall are 1.47 and 3.0 m, respectively. In order to get a better analysis of the heat storage and heat release performance of soil wall, the five testing layers of temperature were arranged in the north wall of greenhouse. The testing period was from Dec. 1st, 2014 to Jan. 30th, 2015. The outdoor weather conditions, indoor air temperature and interior wall temperature were monitored during the testing period. The variation regularity of the indoor and interior wall temperature was analyzed according to the monitoring data in the coldest season (from Dec. 20th, 2014 to Jan. 19th, 2015). The results showed that the testing point temperature of wall surface and interior wall (0.1-0.6 m) presented periodicity variation regularity with the indoor temperature variation in greenhouse, and temperature fluctuation amplitude reduced gradually, at the same time the phase was lags obviously along the wall thickness direction. Moreover, it showed that the interior wall (0-0.6 m) could be considered as the heat storage and heat release body in the soil wall. The heat storage body in the soil wall had large temperature fluctuation, which could be used for storing heat during daytime and releasing heat into the solar greenhouse during night. Besides that, the temperature fluctuation of testing point behind 0.7 m tended to the stabilization, which was in the process of the steady-state heat transfer from the soil wall to outdoors and could be

  2. Mitigation strategies for greenhouse gas emissions from animal production systems: synergy between measuring and modelling at different scales

    NARCIS (Netherlands)

    Groenigen, van J.W.; Schils, R.L.M.; Velthof, G.L.; Kuikman, P.J.; Oudendag, D.A.; Oenema, O.

    2008-01-01

    Animal production systems are large and complex sources of greenhouse gases (GHG), especially nitrous oxide (N2O) and methane (CH4). Emissions from these systems are expected to rise over the coming decades due to the increasing global population and shifting diets, unless appropriate mitigation str

  3. Hydrogen Greenhouse Planets Beyond the Habitable Zone

    CERN Document Server

    Pierrehumbert, Raymond

    2011-01-01

    We show that collision-induced absorption allows molecular hydrogen to act as an incondensible greenhouse gas, and that bars or tens of bars of primordial H2-He mixtures can maintain surface temperatures above the freezing point of water well beyond the "classical" habitable zone defined for CO2 greenhouse atmospheres. Using a 1-D radiative-convective model we find that 40 bars of pure H2 on a 3 Earth-mass planet can maintain a surface temperature of 280K out to 1.5AU from an early-type M dwarf star and 10 AU from a G-type star. Neglecting the effects of clouds and of gaseous absorbers besides H2, the flux at the surface would be sufficient for photosynthesis by cyanobacteria (in the G star case) or anoxygenic phototrophs (in the M star case). We argue that primordial atmospheres of one to several hundred bars of H2-He are possible, and use a model of hydrogen escape to show that such atmospheres are likely to persist further than 1.5 AU from M stars, and 2 AU from G stars, assuming these planets have protect...

  4. The greenhouse effect in a gray planetary atmosphere.

    Science.gov (United States)

    Wildt, R.

    1966-01-01

    Hopf analytical solution for values of ratio of gray absorption coefficients for insolating and escaping radiation /greenhouse parameter/ assumed constant at all depths, presenting temperature distribution graphs

  5. Temperature Buffer Test. Final THM modelling

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Malmberg, Daniel; Boergesson, Lennart; Hernelind, Jan [Clay Technology AB, Lund (Sweden); Ledesma, Alberto; Jacinto, Abel [UPC, Universitat Politecnica de Catalunya, Barcelona (Spain)

    2012-01-15

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modelling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aespoe HRL. It was installed during the spring of 2003. Two heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by bentonite only, whereas the upper heater was surrounded by a composite barrier, with a sand shield between the heater and the bentonite. The test was dismantled and sampled during the winter of 2009/2010. This report presents the final THM modelling which was resumed subsequent to the dismantling operation. The main part of this work has been numerical modelling of the field test. Three different modelling teams have presented several model cases for different geometries and different degree of process complexity. Two different numerical codes, Code{sub B}right and Abaqus, have been used. The modelling performed by UPC-Cimne using Code{sub B}right, has been divided in three subtasks: i) analysis of the response observed in the lower part of the test, by inclusion of a number of considerations: (a) the use of the Barcelona Expansive Model for MX-80 bentonite; (b) updated parameters in the vapour diffusive flow term; (c) the use of a non-conventional water retention curve for MX-80 at high temperature; ii) assessment of a possible relation between the cracks observed in the bentonite blocks in the upper part of TBT, and the cycles of suction and stresses registered in that zone at the start of the experiment; and iii) analysis of the performance, observations and interpretation of the entire test. It was however not possible to carry out a full THM analysis until the end of the test due to

  6. Temperature Buffer Test. Final THM modelling

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Malmberg, Daniel; Boergesson, Lennart; Hernelind, Jan [Clay Technology AB, Lund (Sweden); Ledesma, Alberto; Jacinto, Abel [UPC, Universitat Politecnica de Catalunya, Barcelona (Spain)

    2012-01-15

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modelling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aespoe HRL. It was installed during the spring of 2003. Two heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by bentonite only, whereas the upper heater was surrounded by a composite barrier, with a sand shield between the heater and the bentonite. The test was dismantled and sampled during the winter of 2009/2010. This report presents the final THM modelling which was resumed subsequent to the dismantling operation. The main part of this work has been numerical modelling of the field test. Three different modelling teams have presented several model cases for different geometries and different degree of process complexity. Two different numerical codes, Code{sub B}right and Abaqus, have been used. The modelling performed by UPC-Cimne using Code{sub B}right, has been divided in three subtasks: i) analysis of the response observed in the lower part of the test, by inclusion of a number of considerations: (a) the use of the Barcelona Expansive Model for MX-80 bentonite; (b) updated parameters in the vapour diffusive flow term; (c) the use of a non-conventional water retention curve for MX-80 at high temperature; ii) assessment of a possible relation between the cracks observed in the bentonite blocks in the upper part of TBT, and the cycles of suction and stresses registered in that zone at the start of the experiment; and iii) analysis of the performance, observations and interpretation of the entire test. It was however not possible to carry out a full THM analysis until the end of the test due to

  7. The Impact of Secondary School Students' Preconceptions on the Evolution of their Mental Models of the Greenhouse effect and Global Warming

    Science.gov (United States)

    Reinfried, Sibylle; Tempelmann, Sebastian

    2014-01-01

    This paper provides a video-based learning process study that investigates the kinds of mental models of the atmospheric greenhouse effect 13-year-old learners have and how these mental models change with a learning environment, which is optimised in regard to instructional psychology. The objective of this explorative study was to observe and analyse the learners' learning pathways according to their previous knowledge in detail and to understand the mental model formation processes associated with them more precisely. For the analysis of the learning pathways, drawings, texts, video and interview transcripts from 12 students were studied using qualitative methods. The learning pathways pursued by the learners significantly depend on their domain-specific previous knowledge. The learners' preconceptions could be typified based on specific characteristics, whereby three preconception types could be formed. The 'isolated pieces of knowledge' type of learners, who have very little or no previous knowledge about the greenhouse effect, build new mental models that are close to the target model. 'Reduced heat output' type of learners, who have previous knowledge that indicates compliances with central ideas of the normative model, reconstruct their knowledge by reorganising and interpreting their existing knowledge structures. 'Increasing heat input' type of learners, whose previous knowledge consists of subjective worldly knowledge, which has a greater personal explanatory value than the information from the learning environment, have more difficulties changing their mental models. They have to fundamentally reconstruct their mental models.

  8. Greenhouse gases and recovery of the Earth's ozone layer

    Science.gov (United States)

    Dyominov, I. G.; Zadorozhny, A. M.

    A numerical two-dimension zonally average interactive dynamical radiative-photochemical model of the atmosphere is used for investigation the role of the greenhouse gases CO2, CH4, and N2O in the recovery of the Earth's ozone layer after reduction of anthropogenic discharges in the atmosphere of chlorine and bromine compounds. The model allows calculating self-consistently diabatic circulation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the South to North Poles, as well as distribution of sulphate aerosol particles and polar stratospheric clouds of types I and II. The scenarios of future changes of the greenhouse gases and chlorine and bromine species are taken from Climate Change 1995. The calculations show that expected cooling of the stratosphere caused by the increasing of the greenhouse gases, particularly CO2, enhances the ozone concentration in the stratosphere due to a weakness of the efficiencies of all catalytic cycles of the ozone destruction caused by temperature dependencies of photochemical reactions. The result of this effect is a significant acceleration of the ozone layer recovery after reduction of anthropogenic discharges in the atmosphere of chlorine and bromine species. On the other hand, the cooling of the stratosphere intensifies a formation of the polar stratospheric clouds in the lower stratosphere in the Polar Regions. Heterogeneous reactions on the polar stratospheric clouds, which are the key processes in the destruction of the ozone layer at the high latitudes, lead to more intensive ozone depletion here, which causes a delay of the ozone layer recovery. The calculations show that this effect is weaker than the first one so that the global ozone will recover faster under conditions of continuing anthropogenic growth of the greenhouse gases. The model predicts in this case that the annual average global ozone will reach its undisturbed level of 1980 by about 2040. If the growth of the

  9. The role of long-lived greenhouse gases as principal LW control knob that governs the global surface temperature for past and future climate change

    Energy Technology Data Exchange (ETDEWEB)

    Lacis, Andrew A.; Hansen, James E.; Russell, Gary L.; Oinas, Valdar; Jonas, Jeffrey [NASA Goddard Inst. for Space Studies, New York (United States)], e-mail: Andrew.A.Lacis@nasa.gov

    2013-11-15

    The climate system of the Earth is endowed with a moderately strong greenhouse effect that is characterised by non-condensing greenhouse gases (GHGs) that provide the core radiative forcing. Of these, the most important is atmospheric CO{sub 2}. There is a strong feedback contribution to the greenhouse effect by water vapour and clouds that is unique in the solar system, exceeding the core radiative forcing due to the non-condensing GHGs by a factor of three. The significance of the non-condensing GHGs is that once they have been injected into the atmosphere, they remain there virtually indefinitely because they do not condense and precipitate from the atmosphere, their chemical removal time ranging from decades to millennia. Water vapour and clouds have only a short lifespan, with their distribution determined by the locally prevailing meteorological conditions, subject to Clausius-Clapeyron constraint. Although solar irradiance is the ultimate energy source that powers the terrestrial greenhouse effect, there has been no discern able long-term trend in solar irradiance since precise monitoring began in the late seventies. This leaves atmospheric CO{sub 2} as the effective control knob driving the current global warming trend. Over geological time scales, volcanoes are the principal source of atmospheric CO{sub 2}, and the weathering of rocks is the principal sink, with the biosphere participating as both a source and a sink. The problem at hand is that human industrial activity is causing atmospheric CO{sub 2}, to increase by 2 ppm yr{sup -1}, whereas the interglacial rate has been 0.005 ppm yr{sup -1}. This is a geologically unprecedented rate to turn the CO{sub 2} climate control knob. This is causing the global warming that threatens the global environment.

  10. The Role of Long-Lived Greenhouse Gases as Principal LW Control Knob that Governs the Global Surface Temperature for Past and Future Climate Change

    Science.gov (United States)

    Lacis, Andrew A.; Hansen, James E.; Russell, Gary L.; Oinas, Valdar; Jonas, Jeffrey

    2013-01-01

    The climate system of the Earth is endowed with a moderately strong greenhouse effect that is characterized by non-condensing greenhouse gases (GHGs) that provide the core radiative forcing. Of these, the most important is atmospheric CO2. There is a strong feedback contribution to the greenhouse effect by water vapor and clouds that is unique in the solar system, exceeding the core radiative forcing due to the non-condensing GHGs by a factor of three. The significance of the non-condensing GHGs is that once they have been injected into the atmosphere, they remain there virtually indefinitely because they do not condense and precipitate from the atmosphere, their chemical removal time ranging from decades to millennia. Water vapor and clouds have only a short lifespan, with their distribution determined by the locally prevailing meteorological conditions, subject to Clausius-Clapeyron constraint. Although solar irradiance is the ultimate energy source that powers the terrestrial greenhouse effect, there has been no discernible long-term trend in solar irradiance since precise monitoring began in the late 1970s. This leaves atmospheric CO2 as the effective control knob driving the current global warming trend. Over geological time scales, volcanoes are the principal source of atmospheric CO2, and the weathering of rocks is the principal sink, with the biosphere participating as both a source and a sink. The problem at hand is that human industrial activity is causing atmospheric CO2, to increase by 2 ppm per year, whereas the interglacial rate has been 0.005 ppm per year. This is a geologically unprecedented rate to turn the CO2 climate control knob. This is causing the global warming that threatens the global environment.

  11. The role of long-lived greenhouse gases as principal LW control knob that governs the global surface temperature for past and future climate change

    Directory of Open Access Journals (Sweden)

    Andrew A. Lacis

    2013-11-01

    Full Text Available The climate system of the Earth is endowed with a moderately strong greenhouse effect that is characterised by non-condensing greenhouse gases (GHGs that provide the core radiative forcing. Of these, the most important is atmospheric CO2. There is a strong feedback contribution to the greenhouse effect by water vapour and clouds that is unique in the solar system, exceeding the core radiative forcing due to the non-condensing GHGs by a factor of three. The significance of the non-condensing GHGs is that once they have been injected into the atmosphere, they remain there virtually indefinitely because they do not condense and precipitate from the atmosphere, their chemical removal time ranging from decades to millennia. Water vapour and clouds have only a short lifespan, with their distribution determined by the locally prevailing meteorological conditions, subject to Clausius–Clapeyron constraint. Although solar irradiance is the ultimate energy source that powers the terrestrial greenhouse effect, there has been no discernable long-term trend in solar irradiance since precise monitoring began in the late 1970s. This leaves atmospheric CO2 as the effective control knob driving the current global warming trend. Over geological time scales, volcanoes are the principal source of atmospheric CO2, and the weathering of rocks is the principal sink, with the biosphere participating as both a source and a sink. The problem at hand is that human industrial activity is causing atmospheric CO2, to increase by 2 ppm yr−1, whereas the interglacial rate has been 0.005 ppm yr−1. This is a geologically unprecedented rate to turn the CO2 climate control knob. This is causing the global warming that threatens the global environment.

  12. The Role of Long-Lived Greenhouse Gases as Principal LW Control Knob that Governs the Global Surface Temperature for Past and Future Climate Change

    Science.gov (United States)

    Lacis, Andrew A.; Hansen, James E.; Russell, Gary L.; Oinas, Valdar; Jonas, Jeffrey

    2013-01-01

    The climate system of the Earth is endowed with a moderately strong greenhouse effect that is characterized by non-condensing greenhouse gases (GHGs) that provide the core radiative forcing. Of these, the most important is atmospheric CO2. There is a strong feedback contribution to the greenhouse effect by water vapor and clouds that is unique in the solar system, exceeding the core radiative forcing due to the non-condensing GHGs by a factor of three. The significance of the non-condensing GHGs is that once they have been injected into the atmosphere, they remain there virtually indefinitely because they do not condense and precipitate from the atmosphere, their chemical removal time ranging from decades to millennia. Water vapor and clouds have only a short lifespan, with their distribution determined by the locally prevailing meteorological conditions, subject to Clausius-Clapeyron constraint. Although solar irradiance is the ultimate energy source that powers the terrestrial greenhouse effect, there has been no discernible long-term trend in solar irradiance since precise monitoring began in the late 1970s. This leaves atmospheric CO2 as the effective control knob driving the current global warming trend. Over geological time scales, volcanoes are the principal source of atmospheric CO2, and the weathering of rocks is the principal sink, with the biosphere participating as both a source and a sink. The problem at hand is that human industrial activity is causing atmospheric CO2, to increase by 2 ppm per year, whereas the interglacial rate has been 0.005 ppm per year. This is a geologically unprecedented rate to turn the CO2 climate control knob. This is causing the global warming that threatens the global environment.

  13. Models and Techniques That Project an Arid Greenhouse Future Also Project a Wet Last Glacial Maximum, Contrary to Pollen and Dust Evidence

    Science.gov (United States)

    Scheff, J.; Seager, R.; Coats, S.; Liu, H.

    2015-12-01

    Precipitation (P) and Penman-Monteith potential evapotranspiration (PET) from global climate models (GCMs) have been used to infer that Earth's land areas will dry out under future greenhouse warming outside of the high latitudes. This has been argued using simulated declines in both the aridity index P/PET (by the present author among others) and the Palmer drought index, driven by warming-powered PET increases. However, this picture is at odds with the broad paleoclimate tenet that greenhouse eras in fact appear "wet" on land while cold intervals appear "dry." Here, we show that the same GCMs which project widespread P/PET declines for the greenhouse future also project fairly widespread P/PET increases (i.e. "wetting") for the last glacial maximum (LGM), when CO2 was half present levels and snow and ice were extensive. Yet, global pollen and dust records of the LGM suggest mostly "drier"-looking vegetation patterns than today, as we also review here. Thus, either the GCMs' P and/or PET responses to past global change are flawed, or, P/PET change is not relevant for the vegetation response to CO2-driven climate change. Either way, this calls into question the ecological relevance of the above "drying-out" conclusions. We also show parallel results for the Palmer index, and investigate whether the P/PET results seem any more relevant for lakes and other abiotic wetness indicators than for vegetation.

  14. Multi-fingerprint detection and attribution analysis of greenhouse gas, greenhouse gas-plus-aerosol and solar forced climate change

    Energy Technology Data Exchange (ETDEWEB)

    Hegerl, G.C.; Hasselmann, K.; Cubasch, U.; Roeckner, E.; Voss, R. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Mitchell, J.F.B. [Hadley Centre for Climate Prediction and Research, Bracknell (United Kingdom). Meteorological Office; Waszkewitz, J. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)

    1997-09-01

    A multifingerprint analysis is applied to the detection and attribution of anthropogenic climate change. While a single fingerprint is optimal for the detection of climate change, further tests of the statistical consistency of the detected climate change signal with model predictions for different candidate forcing mechanisms require the simultaneous application of several fingerprints. Model-predicted climate change signals are derived from three anthropogenic global warming simulations for the period 1880 to 2049and two simulations forced by estimated changes in solar radiation from 1700 to 1992. In the first global warming simulation, the forcing is by greenhouse gas only, while in the remaining two simulations the direct influence of sulfate aerosols is also included. From the climate change signals of the greenhouse gas only and the average of the two greenhouse gas-plus-aerosol simulations, two optimized fingerprint patterns are derived by weighting the model-predicted climate change patterns towards low-noise directions. The optimized fingerprint patterns are then applied as a filter to the observed near-surface temperature trend patterns, yielding several detection variables. The space-time structure of natural climate variability needed to determine the optimal fingerprint pattern and the resultant signal-to-noise ratio of the detection variable is estimated from several multicentury control simulations with different CGCMs and from instrumental data over the last 136 y. Applying the combined greenhouse gas-plus-aerosol fingerprint in the same way as the greenhouse gas only fingerprint in a previous work, the recent 30-y trends (1966-1995) of annual mean near surface temperature are again found to represent a significant climate change at the 97.5% confidence level. (orig.) With 13 figs., 3 tabs., 63 refs.

  15. A Hiatus of the Greenhouse Effect.

    Science.gov (United States)

    Song, Jinjie; Wang, Yuan; Tang, Jianping

    2016-09-12

    The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth's surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown.

  16. A Hiatus of the Greenhouse Effect

    Science.gov (United States)

    Song, Jinjie; Wang, Yuan; Tang, Jianping

    2016-09-01

    The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth’s surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown.

  17. A Design of Automatic Greenhouse Temperature and Humidity Control System Based on Single Chip Microcomputer%基于单片机的温室温湿度自动控制系统设计

    Institute of Scientific and Technical Information of China (English)

    薛金水; 杨吉

    2016-01-01

    To meet the requirements of greenhouse temperature and humidity control, a hardware and software system for automatic temperature and humidity control based on single chip microcomputer is designed. The design can effectively control the greenhouse environment to help improve the growing quality for plants. With some minor modifications, the system can also be applied to other conditions of changeable temperature and humidity, which proves that the design has good transferability.%根据温室大棚对温湿度控制的需要,设计了基于于单片机的温度湿度自动控制硬件和软件系统。本设计可以有效控制温室大棚的生长环境,提高了植物的生长质量。此控制方法经稍加改动便可以灵活地运用到其他温湿度变化的控制场合,具有较好的可移植性。

  18. Multi-model attribution of upper-ocean temperature changes using an isothermal approach.

    Science.gov (United States)

    Weller, Evan; Min, Seung-Ki; Palmer, Matthew D; Lee, Donghyun; Yim, Bo Young; Yeh, Sang-Wook

    2016-06-01

    Both air-sea heat exchanges and changes in ocean advection have contributed to observed upper-ocean warming most evident in the late-twentieth century. However, it is predominantly via changes in air-sea heat fluxes that human-induced climate forcings, such as increasing greenhouse gases, and other natural factors such as volcanic aerosols, have influenced global ocean heat content. The present study builds on previous work using two different indicators of upper-ocean temperature changes for the detection of both anthropogenic and natural external climate forcings. Using simulations from phase 5 of the Coupled Model Intercomparison Project, we compare mean temperatures above a fixed isotherm with the more widely adopted approach of using a fixed depth. We present the first multi-model ensemble detection and attribution analysis using the fixed isotherm approach to robustly detect both anthropogenic and natural external influences on upper-ocean temperatures. Although contributions from multidecadal natural variability cannot be fully removed, both the large multi-model ensemble size and properties of the isotherm analysis reduce internal variability of the ocean, resulting in better observation-model comparison of temperature changes since the 1950s. We further show that the high temporal resolution afforded by the isotherm analysis is required to detect natural external influences such as volcanic cooling events in the upper-ocean because the radiative effect of volcanic forcings is short-lived.

  19. Multi-model attribution of upper-ocean temperature changes using an isothermal approach

    Science.gov (United States)

    Weller, Evan; Min, Seung-Ki; Palmer, Matthew D.; Lee, Donghyun; Yim, Bo Young; Yeh, Sang-Wook

    2016-06-01

    Both air-sea heat exchanges and changes in ocean advection have contributed to observed upper-ocean warming most evident in the late-twentieth century. However, it is predominantly via changes in air-sea heat fluxes that human-induced climate forcings, such as increasing greenhouse gases, and other natural factors such as volcanic aerosols, have influenced global ocean heat content. The present study builds on previous work using two different indicators of upper-ocean temperature changes for the detection of both anthropogenic and natural external climate forcings. Using simulations from phase 5 of the Coupled Model Intercomparison Project, we compare mean temperatures above a fixed isotherm with the more widely adopted approach of using a fixed depth. We present the first multi-model ensemble detection and attribution analysis using the fixed isotherm approach to robustly detect both anthropogenic and natural external influences on upper-ocean temperatures. Although contributions from multidecadal natural variability cannot be fully removed, both the large multi-model ensemble size and properties of the isotherm analysis reduce internal variability of the ocean, resulting in better observation-model comparison of temperature changes since the 1950s. We further show that the high temporal resolution afforded by the isotherm analysis is required to detect natural external influences such as volcanic cooling events in the upper-ocean because the radiative effect of volcanic forcings is short-lived.

  20. Energy scenarios and greenhouse effect gases emissions model for Mexico; Modelo de escenarios energeticos y de emisiones de gases de efecto invernadero para Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum Pardo, Claudia; Rodriguez Viqueira, Luis [Instituto de Ingenieria de la UNAM, Mexico, D. F. (Mexico)

    1998-12-31

    This paper presents the bases for the Model of Energy and Greenhouse Emission Scenarios (MEEEM) developed by the Instituto de Ingenieria de la UNAM (Universidad Nacional Autonoma de Mexico`s Engineering Institute). This model was built with the objective of analyzing the different technological options for the mitigation of the greenhouse gases effect on Mexico. The MEEEM is a model for the end uses that simulate in a simple way the energy demand, transformation and supply and calculates the differential leveled costs among a basic scenario and several mitigation scenarios of the greenhouse emissions. The article also presents some of the results in evaluating three technologies of renewable energy sources. Although the model is perfectible, its development shows its usefulness in this type of models in the decision taking for the energy and environmental planning of the country. [Espanol] Este articulo presenta las bases del Modelo de Escenarios Energeticos y de Emisiones de Gases de Efecto Invernadero para Mexico (MEEEM), desarrollado por el Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM). Este modelo fue construido con el objetivo de analizar las diversas opciones tecnologicas de mitigacion de gases de efecto invernadero para Mexico. El MEEEM es un modelo de usos finales que simula de una manera sencilla, la demanda, transformacion y oferta de la energia y calcula la diferencia de costos nivelados entre un escenario base y diversos escenarios de mitigacion de emisiones de gases de efecto invernadero. El articulo presenta tambien algunos resultados obtenidos al evaluar tres tecnologias de fuentes renovables de energia. Aun cuando el modelo es perfectible, su desarrollo demuestra la utilidad de este tipo de modelos en la toma de decisiones para planeacion energetica y ambiental del pais.

  1. Removal of phosphate from greenhouse wastewater using hydrated lime.

    Science.gov (United States)

    Dunets, C Siobhan; Zheng, Youbin

    2014-01-01

    Phosphate (P) contamination in nutrient-laden wastewater is currently a major topic of discussion in the North American greenhouse industry. Precipitation of P as calcium phosphate minerals using hydrated lime could provide a simple, inexpensive method for retrieval. A combination of batch experiments and chemical equilibrium modelling was used to confirm the viability of this P removal method and determine lime addition rates and pH requirements for greenhouse wastewater of varying nutrient compositions. Lime: P ratio (molar ratio of CaMg(OH)₄: PO₄‒P) provided a consistent parameter for estimating lime addition requirements regardless of initial P concentration, with a ratio of 1.5 providing around 99% removal of dissolved P. Optimal P removal occurred when lime addition increased the pH from 8.6 to 9.0, suggesting that pH monitoring during the P removal process could provide a simple method for ensuring consistent adherence to P removal standards. A Visual MINTEQ model, validated using experimental data, provided a means of predicting lime addition and pH requirements as influenced by changes in other parameters of the lime-wastewater system (e.g. calcium concentration, temperature, and initial wastewater pH). Hydrated lime addition did not contribute to the removal of macronutrient elements such as nitrate and ammonium, but did decrease the concentration of some micronutrients. This study provides basic guidance for greenhouse operators to use hydrated lime for phosphate removal from greenhouse wastewater.

  2. Carbon dioxide and climate impulse response functions for the computation of greenhouse gas metrics: a multi-model analysis

    Directory of Open Access Journals (Sweden)

    F. Joos

    2013-03-01

    Full Text Available The responses of carbon dioxide (CO2 and other climate variables to an emission pulse of CO2 into the atmosphere are often used to compute the Global Warming Potential (GWP and Global Temperature change Potential (GTP, to characterize the response timescales of Earth System models, and to build reduced-form models. In this carbon cycle-climate model intercomparison project, which spans the full model hierarchy, we quantify responses to emission pulses of different magnitudes injected under different conditions. The CO2 response shows the known rapid decline in the first few decades followed by a millennium-scale tail. For a 100 Gt-C emission pulse added to a constant CO2 concentration of 389 ppm, 25 ± 9% is still found in the atmosphere after 1000 yr; the ocean has absorbed 59 ± 12% and the land the remainder (16 ± 14%. The response in global mean surface air temperature is an increase by 0.20 ± 0.12 °C within the first twenty years; thereafter and until year 1000, temperature decreases only slightly, whereas ocean heat content and sea level continue to rise. Our best estimate for the Absolute Global Warming Potential, given by the time-integrated response in CO2 at year 100 multiplied by its radiative efficiency, is 92.5 × 10−15 yr W m−2 per kg-CO2. This value very likely (5 to 95% confidence lies within the range of (68 to 117 × 10−15 yr W m−2 per kg-CO2. Estimates for time-integrated response in CO2 published in the IPCC First, Second, and Fourth Assessment and our multi-model best estimate all agree within 15% during the first 100 yr. The integrated CO2 response, normalized by the pulse size, is lower for pre-industrial conditions, compared to present day, and lower for smaller pulses than larger pulses. In contrast, the response in temperature, sea level and ocean heat content is less sensitive to these choices. Although, choices in pulse size, background concentration, and model lead to uncertainties, the most important and

  3. Light and temperature performance of energy-saving solar greenhouse assembled with color plate%彩钢板保温装配式节能日光温室的温光性能

    Institute of Scientific and Technical Information of China (English)

    孙周平; 黄文永; 李天来; 佟雪娇; 白义奎; 马健

    2013-01-01

    ,which has completely resolved the problem on the year-round vegetable supply, especially in winter in north China. However, the CESG also faces many problems such as uneven distribution of light and temperature in greenhouse, difficulties to achieve automatic control of outside heat preservation covering materials, poor ability of rainproof, snow-proof, wind-proof and fire-proof, and destruction of lots of arable land for greenhouse construction of earth wall and brick wall. To resolve the above problems, a new type of energy-saving solar greenhouse assembled with heat preservation color plate (CPSG) was developed in Lingyuan (latitude 41?20'N, longitude 119?31'E), Liaoning province, China from 2010 to 2012. The light and temperature performances were studied from January to March, 2013.The CPSG was the large scale arched structure with a span of 12 m, a ridge height of 5.5m, a length of 65m, a front roof lighting angle of 41.5°, a front roof covering materials of polyolefin film. The skeleton structure was semi-circular arc, which slide to opening or closing the heat preservation covering materials of rock wool color plate outside, and to move the opening or closing of the rock wool color plate east gable (in the morning) and west gable (in the afternoon) respectively. As a result, the CPSG not only resolved the problem of rain-proof, snow-proof, wind-proof and fire-proof for Chinese traditional solar greenhouse, but also brought about the accurate operation of outside heat preservation color plate. Furthermore, this type of greenhouse adopted water-recycle heat storage-release system (WHSS) and air-underground heat exchange storage-release system(AHESS). WHSS is running 5.5h/d on sunny day and the solar energy storage capacity is 1200kJ/m2 (greenhouse area), which made the greenhouse temperature increase 7-8℃ in winter night. At the same time, solar energy accumulation for AHESS is 221kJ/m2, which shows that two heat storage-release systems may replace the heat

  4. The greenhouse and antigreenhouse effects on Titan

    Science.gov (United States)

    Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

    1991-01-01

    The parallels between the atmospheric thermal structure of the Saturnian satellite Titan and the hypothesized terrestrial greenhouse effect can serve as bases for the evaluation of competing greenhouse theories. Attention is presently drawn to the similarity between the roles of H2 and CH4 on Titan and CO2 and H2O on earth. Titan also has an antigreenhouse effect due to a high-altitude haze layer which absorbs at solar wavelengths, while remaining transparent in the thermal IR; if this haze layer were removed, the antigreenhouse effect would be greatly reduced, exacerbating the greenhouse effect and raising surface temperature by over 20 K.

  5. Greenhouses for food production and the environment

    Directory of Open Access Journals (Sweden)

    Abdeen Mustafa Omer

    2016-01-01

    Full Text Available A greenhouse is essentially an enclosed structure, which traps the short wavelength solar radiation and stores the long wavelength thermal radiation to create a favourable microclimate for higher productivity. The sun’s radiation incident on the greenhouse has two parts: direct radiation and an associated diffuse sky radiation. The diffuse part is not focused by the lenses and goes right through Frensel lenses onto the surface of the absorbers. This energy is absorbed and transformed into heat, which is then transported via the liquid medium in copper pipes to the water (heat storage tanks or, if used, open fish tanks. In this way, an optimal temperature for both plant cultivation and fish production can be maintained. Stable plant growth conditions are light, temperature and air humidity. Light for the photosynthesis of plants comes from the diffuse radiation, which is without substantial fluctuations and variation throughout most of the day. The air temperature inside the greenhouse is one of the factors that have an influence on the precocity of production. The selective collector acts in a more perceptible way on extreme air temperatures inside the greenhouse. Hence, the system makes it possible to avoid the excessive deviation of the temperature inside the greenhouse and provides a favourable microclimate for the precocity of the culture. Sediment and some associated water from the sediment traps are used as organic fertiliser for the plant cultivation. The present trend in greenhouse cultivation is to extend the crop production season in order to maximise use of the equipment and increase annual productivity and profitability. However, in many Mediterranean greenhouses, such practices are limited because the improper cooling methods (mainly natural or forced ventilation used do not provide the desired micro-climatic condition during the summer of a composite climate. Also, some of these greenhouses have been built where the

  6. Analytic Models of High-Temperature Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Stygar, W.A.; Olson, R.E.; Spielman, R.B.; Leeper, R.J.

    2000-11-29

    A unified set of high-temperature-hohlraum models has been developed. For a simple hohlraum, P{sub s} = [A{sub s}+(1{minus}{alpha}{sub W})A{sub W}+A{sub H}]{sigma}T{sub R}{sup 4} + (4V{sigma}/c)(dT{sub R}{sup r}/dt) where P{sub S} is the total power radiated by the source, A{sub s} is the source area, A{sub W} is the area of the cavity wall excluding the source and holes in the wall, A{sub H} is the area of the holes, {sigma} is the Stefan-Boltzmann constant, T{sub R} is the radiation brightness temperature, V is the hohlraum volume, and c is the speed of light. The wall albedo {alpha}{sub W} {triple_bond} (T{sub W}/T{sub R}){sup 4} where T{sub W} is the brightness temperature of area A{sub W}. The net power radiated by the source P{sub N} = P{sub S}-A{sub S}{sigma}T{sub R}{sup 4}, which suggests that for laser-driven hohlraums the conversion efficiency {eta}{sub CE} be defined as P{sub N}/P{sub LASER}. The characteristic time required to change T{sub R}{sup 4} in response to a change in P{sub N} is 4V/C[(l{minus}{alpha}{sub W})A{sub W}+A{sub H}]. Using this model, T{sub R}, {alpha}{sub W}, and {eta}{sub CE} can be expressed in terms of quantities directly measurable in a hohlraum experiment. For a steady-state hohlraum that encloses a convex capsule, P{sub N} = {l_brace}(1{minus}{alpha}{sub W})A{sub W}+A{sub H}+[(1{minus}{alpha}{sub C})(A{sub S}+A{sub W}{alpha}{sub W})A{sub C}/A{sub T}]{r_brace}{sigma}T{sub RC}{sup 4} where {alpha}{sub C} is the capsule albedo, A{sub C} is the capsule area, A{sub T} {triple_bond} (A{sub S}+A{sub W}+A{sub H}), and T{sub RC} is the brightness temperature of the radiation that drives the capsule. According to this relation, the capsule-coupling efficiency of the baseline National-Ignition-Facility (NIF) hohlraum is 15% higher than predicted by previous analytic expressions. A model of a hohlraum that encloses a z pinch is also presented.

  7. Subsurface temperature of the onshore Netherlands: new temperature dataset and modelling

    NARCIS (Netherlands)

    Bonté, D.; Wees, J.-D. van; Verweij, J.M.

    2012-01-01

    Subsurface temperature is a key parameter for geothermal energy prospection in sedimentary basins. Here, we present the results of a 3D temperature modelling using a thermal-tectonic forward modelling method, calibrated with subsurface temperature measurements in the Netherlands. The first step invo

  8. 温室草莓灰霉病T-S模糊控制模型%T-S fuzzy model and control for Botrytis cinerea of greenhouse strawberry

    Institute of Scientific and Technical Information of China (English)

    闻飞祥; 赵立纯; 刘敬娜; 韩立红

    2015-01-01

    Combined Logistic model of biological population with the fuzziness of Botrytis cinerea, the corre-sponding T-S fuzzy model for the Botrytis cinerea of greenhouse strawberry is proposed. According to the sta-bility theory of Lyapunov, some sufficient conditions which make the T-S fuzzy model stable are obtained. Fur-ther, the controllers which make the model global stable are designed to realize the prevention and control for the Botrytis cinerea of greenhouse strawberry. Finally, the simulations are carried out to prove the correctness of the conclusion by means of Matlab software.%基于生物种群的Logistic增长模型,结合灰霉病病菌的模糊性,建立温室草莓灰霉病病菌的T-S模糊模型.根据Lyapunov稳定性定理,给出所建T-S模糊控制系统稳定的充分条件,并设计控制器,使模型全局稳定,实现对温室草莓灰霉病的预防与控制.最后利用Matlab进行数值仿真,以验证结论的正确性.

  9. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

  10. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment concentrati

  11. CO2, the greenhouse effect and global warming: from the pioneering work of Arrhenius and Callendar to today's Earth System Models

    OpenAIRE

    2016-01-01

    Climate warming during the course of the twenty-first century is projected to be between 1.0 and 3.7 °C depending on future greenhouse gas emissions, based on the ensemble-mean results of state-of-the-art Earth System Models (ESMs). Just how reliable are these projections, given the complexity of the climate system? The early history of climate research provides insight into the understanding and science needed to answer this question. We examine the mathematical quantifications of planetary ...

  12. Modeling Phloem Temperatures Relative to Mountain Pine Beetle Phenology

    OpenAIRE

    Lewis, Matthew Jared

    2011-01-01

    We explore a variety of methods to estimate phloem temperatures from ambient air temperatures suitable for the mountain pine beetle, Dendroctonus ponderosae. A model's ability to induce the same phenology generated from observed phloem temperatures measures its effectiveness rather than a simple reconstruction of phloem temperatures. From a model's phenology results we are able to ascertain whether the model produces a similar amount of developmental energy exhibited by observed phloem temper...

  13. Greenhouse Effect Detection Experiment (GEDEX). Selected data sets

    Science.gov (United States)

    Olsen, Lola M.; Warnock, Archibald, III

    1992-01-01

    This CD-ROM contains selected data sets compiled by the participants of the Greenhouse Effect Detection Experiment (GEDEX) workshop on atmospheric temperature. The data sets include surface, upper air, and/or satellite-derived measurements of temperature, solar irradiance, clouds, greenhouse gases, fluxes, albedo, aerosols, ozone, and water vapor, along with Southern Oscillation Indices and Quasi-Biennial Oscillation statistics.

  14. Relationship between the Time of Taking off and Covering the Curtain and Temperature Change in Sunlight Greenhouse%揭帘、盖帘时间与日光温室内气温变化的关系

    Institute of Scientific and Technical Information of China (English)

    王英师; 陈建中; 陈永杰

    2014-01-01

    试验从2011年11月1日至2012年3月31日对每天揭帘时间分别为9:00和10:00、盖帘时间分别为15:00和16:00的两个日光温室内气温和室外气温进行了连续实时测量,研究了揭帘、盖帘时间对日光温室气温变化的影响。结果表明,揭帘、盖帘时间对温室气温的变化产生明显的影响,其影响程度随着季节和天气状况的变化而变化。在初冬和早春的晴天里,适当早揭帘晚盖帘,有益于延长光照时间,改善作物生长环境;在寒冷的季节,适当迟揭帘早盖帘,有利于保持和提高温室温度。在室外气温≤-9.0℃时,温室内气温将降低到5.0℃及其以下,对喜温作物产生不利影响,必要时要采取短期人工增温措施。%Two sunlight greenhouse's indoor and outdoor air temperature that the time of taking off the curtain is between 9 am and 10 am and the time of covering the curtain is between 3 pm and 4 pm from November 11, 2011 to march 31, 2012 were measured timely and successively. The effects of the time of taking off and covering the curtain on temperature change in Sunlight greenhouse was studied. The results showed that the time of taking off and covering the curtain had a ob-vious effect on the air temperature change in sunlight greenhouse, varing with the seasons and weather conditions. In the early winter and early spring sunny day, it is advised to take off the curtain early and cover the curtain late, good for the increasing of the light period length and the environment’s improvement of crop growth. In the frigid months, it is advised to take off the curtain late and cover the curtain early, which benefits to keep and improve the temperature of the Sunlight Greenhouse. When the outdoor’s temperature is below -9 degree, the indoor’s temperature would drop to less than 5 de-gree, bad for the growth of temperature-bias plants and the artificial measures should be used to increase temperature.

  15. Whole-farm models to quantify greenhouse gas emissions and their potential use for linking climate change mitigation and adaptation in temperate grassland ruminant-based farming systems.

    Science.gov (United States)

    Del Prado, A; Crosson, P; Olesen, J E; Rotz, C A

    2013-06-01

    The farm level is the most appropriate scale for evaluating options for mitigating greenhouse gas (GHG) emissions, because the farm represents the unit at which management decisions in livestock production are made. To date, a number of whole farm modelling approaches have been developed to quantify GHG emissions and explore climate change mitigation strategies for livestock systems. This paper analyses the limitations and strengths of the different existing approaches for modelling GHG mitigation by considering basic model structures, approaches for simulating GHG emissions from various farm components and the sensitivity of GHG outputs and mitigation measures to different approaches. Potential challenges for linking existing models with the simulation of impacts and adaptation measures under climate change are explored along with a brief discussion of the effects on other ecosystem services.

  16. Geothermal Greenhouse Information Package

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, K. [P.E.; Boyd, T. [ed.

    1997-01-01

    This package of information is intended to provide a foundation of background information for developers of geothermal greenhouses. The material is divided into seven sections covering such issues as crop culture and prices, operating costs for greenhouses, heating system design, vendors and a list of other sources of information.

  17. Greenhouse Gas Emissions from Stored Dairy Slurry from Multiple Farms.

    Science.gov (United States)

    Le Riche, Etienne L; VanderZaag, Andrew C; Wood, Jeffrey D; Wagner-Riddle, Claudia; Dunfield, Kari; Ngwabie, N Martin; McCabe, John; Gordon, Robert J

    2016-11-01

    A significant need exists to improve our understanding of the extent of greenhouse gas emissions from the storage of livestock manure to both improve the reliability of inventory assessments and the impact of beneficial management practice adoption. Factors affecting the extent and variability of greenhouse gas emissions from stored dairy manure were investigated. Emissions from six slurries stored in clean concrete tanks under identical "warm-season" conditions were monitored consecutively over 173 d (18°C average air temperature). Methane (CH) emissions varied considerably among the manures from 6.3 to 25.9 g m d and accounted for ∼96% of the total CO equivalent greenhouse gas emissions. The duration of the lag period, when methane emissions were near baseline levels, varied from 30 to 90 d from the beginning of storage. As a result, CH emissions were poorly correlated with air temperature prior to the time of peak emissions (i.e., the initial 48 to 108 d of storage) but improved afterward. The air temperature following the time of the peak CH flux and the length of the active methanogenesis period (i.e., when the daily CH emissions ≥ 7.6 g m d) were highly correlated with CH emissions ( = 0.98, < 0.01). Methane conversion factors (MCFs) ranged from 0.08 to 0.52 for the different manures. The MCFs generated from existing CH emission models were correlated ( = 0.68, = 0.02) to MCFs calculated for the active methanogenesis period for manure containing wood bedding. A temperature component was added that improved the accuracy ( = 0.82, < 0.01). This demonstrated that an improved understanding of lag period dynamics will enhance stored dairy manure greenhouse gas emission inventory calculations.

  18. Modelling of temperatures in continental convergence zones

    Energy Technology Data Exchange (ETDEWEB)

    Toksoz, M.N.; Bird, P.

    1977-08-03

    The thermal histories of continent-continent convergence zones are modelled by a finite-difference technique in an attempt to explain geologic observations of heating and melting in such zones. The suture zone between two converging continents divides a passively heated overriding plate from a quiet continental margin which is suddenly deformed in the collision. Both regions may be metamorphosed and intruded. On the continental-shelf side where mountains are formed by underthrusting within the crust, it was found that adiabatic and radioactive heating are negligible during the orogeny. Shear-strain heating may raise the fault zones to about 500/sup 0/C. At higher temperatures, dislocation creep of crustal rocks would be expected from laboratory results. Even high crustal radioactivity will not produce melting in less than 40 m.y. Thus any plutons in this zone (the granites of the Zagros, Urals, and Himalayas) probably result indirectly by melting of crust that is heated by deep asthenospheric intrusions, which may reach the crust at the time of detachment of the oceanic slab, combined with the effects of friction and water along the subduction plane. Across the suture, the thermal history begins before the collision during the oceanic subduction phase. The sinking slab creates asthenospheric circulations, which warm the passive plate from below and intrude it in an Andean-type arc along the suture (Zagros and Himalayan region). If total subduction exceeds about 3000 km the slow warming has time to weaken the plate and extensive crustal shortening may follow the collision. Crustal shortening and thickening is accompanied by differentiation and volcanism (Tibetan and Grenville orogenies). Thermal modelling of Tibet shows that volcanism cannot be produced in the available time by crustal thickening alone, but requires the initial warming phase as well.

  19. The development from kinetic coefficients of a predictive model for the growth of Eichhomia crassipes in the field. I. Generating kinetic coefficients for the model in greenhouse culture

    Directory of Open Access Journals (Sweden)

    C. F. Musil

    1984-12-01

    Full Text Available The kinetics of N- and P- limited growth of Eichhornia crassipes (Mart . Solms were investigated in greenhouse culture with the object of developing a model for predicting population sizes, yields, growth rates and frequencies and amounts of harvest, under varying conditions of nutrient loading and climate, to control both nutrient inputs and excessive growth in eutrophied aquatic systems. The kinetic coefficients, maximum specific growth rate (Umax, half saturation coefficient (Ks and yield coefficient (Yc were measured under N and P limitation in replicated batch culture experiments. Umax values and Ks concentrations derived under N limitation ranged from 5,37 to 8,86% d + and from 400 to 1 506 µg  N ℓ1respectively. Those derived under P limitation ranged from 4,51 to 10,89% d 1 and from 41 to 162 fig P ℓ1 respectively. Yc values (fresh mass basis determined ranged from 1 660 to 1 981 (87 to 98 dry mass basis for N and from 16 431 to 18 671 (867 to 980 dry mass basis for P. The reciprocals of Yc values (dry mass basis, expressed as percentages, adequately estimated the minimum limiting concentrations of N and P {% dry mass in the plant tissues. Kinetic coefficients determined are compared with those reported for algae. The experimental method used and results obtained are critically assessed.

  20. Arctic climate change: Greenhouse warming unleashed

    Science.gov (United States)

    Mauritsen, Thorsten

    2016-04-01

    Human activity alters the atmospheric composition, which leads to global warming. Model simulations suggest that reductions in emission of sulfur dioxide from Europe since the 1970s could have unveiled rapid Arctic greenhouse gas warming.

  1. 冬季温室气温调控对番茄和黄瓜生长的影响%Effects of Different Temperatures on Growth of Tomato and Cucumber in Winter Greenhouses

    Institute of Scientific and Technical Information of China (English)

    张志雪; 董然; 蒋欣梅; 于锡宏; 吴凤芝

    2015-01-01

    Taking tomato cultivar Beimei and cucumber cultivar Jinzao No.1 as materials and adopting the four-section variable temperature treatment (uncovering quilts-13:00-covering quilts-19:00-uncovering quilts), we studied the effects of different temperatures on the growth of tomato and cucumber in winter greenhouse. The results showed that, during the production in winter greenhouse, when covered PO film with high light transmittance on the greenhouses, the suitable temperature indexes of four-section variable temperature treatments for tomato and cucumber were 26℃-24℃-18℃-12℃and 28℃-25℃-19℃-13℃ respectively, which promoted the growth of tomato and cucumber, and increased relative growth of plant height, stem diameter and leaf area, fruit-setting rate, fruit enlargement speed, chlorophyll content and net photosynthetic rate as well.%采用四段变温管理,即揭棉被—13:00、13:00—盖棉被、盖棉被—19:00、19:00—次日揭棉被,以贝美番茄和津早一号黄瓜为材料,研究了冬季温室气温调控对其生长的影响。研究结果表明,在冬季温室生产中,采用透光率较高的PO膜覆盖和适当较高的四段变温管理,即4个时间段下番茄和黄瓜的温度指标分别为26℃—24℃—18℃—12℃和28℃—25℃—19℃—13℃时,更有利于番茄和黄瓜植株生长,株高、茎粗、叶面积的相对生长量增加,坐果率和果实膨大速度增加,叶片叶绿素含量增加及净光合速率增强。

  2. National Greenhouse Gas Emission Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Greenhouse Gas Emission Inventory contains information on direct emissions of greenhouse gases as well as indirect or potential emissions of greenhouse...

  3. Semi-empirical characterization of a greenhouse-effect cascades solar distiller

    Energy Technology Data Exchange (ETDEWEB)

    Khelif, C.; Touati, B. [Station d' Experimentation des Equipements Solaries en Milieu Saharien, Adrar (Algeria)

    2000-02-01

    The analysis in steady state of the different modelizations made on solar flat-plate functioning in low and average temperatures (especially the bridges of surface water) has allowed us to develop a simple linear model. By a swift experimental way, this model is able to approximate the thermal and optical performances of a greenhouse-effect solar distiller. This model has equally served for the verification of the time constant of the system in the same functioning and environment conditions. (author)

  4. Model of local temperature changes in brain upon functional activation.

    Science.gov (United States)

    Collins, Christopher M; Smith, Michael B; Turner, Robert

    2004-12-01

    Experimental results for changes in brain temperature during functional activation show large variations. It is, therefore, desirable to develop a careful numerical model for such changes. Here, a three-dimensional model of temperature in the human head using the bioheat equation, which includes effects of metabolism, perfusion, and thermal conduction, is employed to examine potential temperature changes due to functional activation in brain. It is found that, depending on location in brain and corresponding baseline temperature relative to blood temperature, temperature may increase or decrease on activation and concomitant increases in perfusion and rate of metabolism. Changes in perfusion are generally seen to have a greater effect on temperature than are changes in metabolism, and hence active brain is predicted to approach blood temperature from its initial temperature. All calculated changes in temperature for reasonable physiological parameters have magnitudes <0.12 degrees C and are well within the range reported in recent experimental studies involving human subjects.

  5. Estimating methane emissions from landfills based on rainfall, ambient temperature, and waste composition: The CLEEN model.

    Science.gov (United States)

    Karanjekar, Richa V; Bhatt, Arpita; Altouqui, Said; Jangikhatoonabad, Neda; Durai, Vennila; Sattler, Melanie L; Hossain, M D Sahadat; Chen, Victoria

    2015-12-01

    Accurately estimating landfill methane emissions is important for quantifying a landfill's greenhouse gas emissions and power generation potential. Current models, including LandGEM and IPCC, often greatly simplify treatment of factors like rainfall and ambient temperature, which can substantially impact gas production. The newly developed Capturing Landfill Emissions for Energy Needs (CLEEN) model aims to improve landfill methane generation estimates, but still require inputs that are fairly easy to obtain: waste composition, annual rainfall, and ambient temperature. To develop the model, methane generation was measured from 27 laboratory scale landfill reactors, with varying waste compositions (ranging from 0% to 100%); average rainfall rates of 2, 6, and 12 mm/day; and temperatures of 20, 30, and 37°C, according to a statistical experimental design. Refuse components considered were the major biodegradable wastes, food, paper, yard/wood, and textile, as well as inert inorganic waste. Based on the data collected, a multiple linear regression equation (R(2)=0.75) was developed to predict first-order methane generation rate constant values k as functions of waste composition, annual rainfall, and temperature. Because, laboratory methane generation rates exceed field rates, a second scale-up regression equation for k was developed using actual gas-recovery data from 11 landfills in high-income countries with conventional operation. The Capturing Landfill Emissions for Energy Needs (CLEEN) model was developed by incorporating both regression equations into the first-order decay based model for estimating methane generation rates from landfills. CLEEN model values were compared to actual field data from 6 US landfills, and to estimates from LandGEM and IPCC. For 4 of the 6 cases, CLEEN model estimates were the closest to actual.

  6. 基于单片机的大棚温湿度控制系统设计%Design of temperature and humidity control system in greenhouse based on MCU

    Institute of Scientific and Technical Information of China (English)

    郭荣艳; 胡翔

    2012-01-01

    针对目前温湿度控制现状,设计了一种大棚温湿度控制系统,给出了系统的硬件电路、软件设计思路.该系统以单片机AT89C52为控制中心,采用SHT71为温湿度检测元件,实时监控温湿度的变化.单片机与智能传感器相连,采集并处理传感器的测量数据;通过LCD12864实时显示温湿度的数值;当温度超出允许范围时,电机开始启动来调节温度,从而实现对整个温湿度控制系统的管理.这种温湿度控制系统具有传感精度高、易于管理等优点.%According to the present situation of temperature and humidity control, a control system on temperature and humidity of greenhouse is designed, consisting of hardware circuit and software design. The system can accomplish real-- time control on temperature and humidity, taking MCU AT89C52 as control core and SHT71 as sensing element of temperature and humidity. MCU and intelligent sensors are linked together, collecting and processing measured datas with intelligent sensor. Real - time temperature and humidity values can be displayed through LCD12864. When temperature exceeds the al- lowable range, the motor will be started to adjust the temperature, so as to management and control the whole temperature and humidity system. This kind of temperature and humidity control system is easily managed with high precision.

  7. Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence.

    Science.gov (United States)

    Amstrup, Steven C; Deweaver, Eric T; Douglas, David C; Marcot, Bruce G; Durner, George M; Bitz, Cecilia M; Bailey, David A

    2010-12-16

    On the basis of projected losses of their essential sea-ice habitats, a United States Geological Survey research team concluded in 2007 that two-thirds of the world's polar bears (Ursus maritimus) could disappear by mid-century if business-as-usual greenhouse gas emissions continue. That projection, however, did not consider the possible benefits of greenhouse gas mitigation. A key question is whether temperature increases lead to proportional losses of sea-ice habitat, or whether sea-ice cover crosses a tipping point and irreversibly collapses when temperature reaches a critical threshold. Such a tipping point would mean future greenhouse gas mitigation would confer no conservation benefits to polar bears. Here we show, using a general circulation model, that substantially more sea-ice habitat would be retained if greenhouse gas rise is mitigated. We also show, with Bayesian network model outcomes, that increased habitat retention under greenhouse gas mitigation means that polar bears could persist throughout the century in greater numbers and more areas than in the business-as-usual case. Our general circulation model outcomes did not reveal thresholds leading to irreversible loss of ice; instead, a linear relationship between global mean surface air temperature and sea-ice habitat substantiated the hypothesis that sea-ice thermodynamics can overcome albedo feedbacks proposed to cause sea-ice tipping points. Our outcomes indicate that rapid summer ice losses in models and observations represent increased volatility of a thinning sea-ice cover, rather than tipping-point behaviour. Mitigation-driven Bayesian network outcomes show that previously predicted declines in polar bear distribution and numbers are not unavoidable. Because polar bears are sentinels of the Arctic marine ecosystem and trends in their sea-ice habitats foreshadow future global changes, mitigating greenhouse gas emissions to improve polar bear status would have conservation benefits throughout

  8. Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence

    Science.gov (United States)

    Amstrup, Steven C.; Deweaver, E.T.; Douglas, D.C.; Marcot, B.G.; Durner, G.M.; Bitz, C.M.; Bailey, D.A.

    2010-01-01

    On the basis of projected losses of their essential sea-ice habitats, a United States Geological Survey research team concluded in 2007 that two-thirds of the worlds polar bears (Ursus maritimus) could disappear by mid-century if business-as-usual greenhouse gas emissions continue. That projection, however, did not consider the possible benefits of greenhouse gas mitigation. A key question is whether temperature increases lead to proportional losses of sea-ice habitat, or whether sea-ice cover crosses a tipping point and irreversibly collapses when temperature reaches a critical threshold. Such a tipping point would mean future greenhouse gas mitigation would confer no conservation benefits to polar bears. Here we show, using a general circulation model, that substantially more sea-ice habitat would be retained if greenhouse gas rise is mitigated. We also show, with Bayesian network model outcomes, that increased habitat retention under greenhouse gas mitigation means that polar bears could persist throughout the century in greater numbers and more areas than in the business-as-usual case. Our general circulation model outcomes did not reveal thresholds leading to irreversible loss of ice; instead, a linear relationship between global mean surface air temperature and sea-ice habitat substantiated the hypothesis that sea-ice thermodynamics can overcome albedo feedbacks proposed to cause sea-ice tipping points. Our outcomes indicate that rapid summer ice losses in models and observations represent increased volatility of a thinning sea-ice cover, rather than tipping-point behaviour. Mitigation-driven Bayesian network outcomes show that previously predicted declines in polar bear distribution and numbers are not unavoidable. Because polar bears are sentinels of the Arctic marine ecosystem and trends in their sea-ice habitats foreshadow future global changes, mitigating greenhouse gas emissions to improve polar bear status would have conservation benefits throughout

  9. Investigating the effect of surface water - groundwater interactions on stream temperature using Distributed temperature sensing and instream temperature model

    DEFF Research Database (Denmark)

    Karthikeyan, Matheswaran; Blemmer, Morten; Mortensen, Julie Flor;

    2011-01-01

    Surface water–groundwater interactions at the stream interface influences, and at times controls the stream temperature, a critical water property driving biogeochemical processes. This study investigates the effects of these interactions on temperature of Stream Elverdamsåen in Denmark using...... the Distributed Temperature Sensing (DTS) system and instream temperature modelling. Locations of surface water–groundwater interactions were identified from the temperature data collected over a 2-km stream reach using a DTS system with 1-m spatial and 5-min temporal resolution. The stream under consideration...... exhibits three distinct thermal regimes within a 2 km reach length due to two major interactions. An energy balance model is used to simulate the instream temperature and to quantify the effect of these interactions on the stream temperature. This research demonstrates the effect of reach level small scale...

  10. Temperature-dependent rate models of vascular cambium cell mortality

    Science.gov (United States)

    Matthew B. Dickinson; Edward A. Johnson

    2004-01-01

    We use two rate-process models to describe cell mortality at elevated temperatures as a means of understanding vascular cambium cell death during surface fires. In the models, cell death is caused by irreversible damage to cellular molecules that occurs at rates that increase exponentially with temperature. The models differ in whether cells show cumulative effects of...

  11. Evaluation of the greenhouse effect. Climate changes: from models to negotiations; Le point sur l`effet de serre. Changement de climat: des modeles aux negociations

    Energy Technology Data Exchange (ETDEWEB)

    Cointe, R. [Ministere de l`Environnement, 75 - Paris (France). Mission interministerielle de l`effet de serre

    1997-01-01

    This paper takes stock of scientific works and negotiations in progress about climatic changes linked with greenhouse effect. The scientists opinion about the noxiousness of greenhouse gases (CO{sub 2}, CH{sub 4}, N{sub 2}O, tropospheric O{sub 3}, CFC and their substitutes) inducing climate warming (0,5 deg. C as an average during the 20. Century) is reported. The forecasting about the evolution and organisation of the international effort (United Nations Climate Convention, Berlin`s Commission), and the French contribution on this topic is analyzed. (N.K.).

  12. Crop management in greenhouses: adapting the growth conditions to the plant needs or adapting the plant to the growth conditions?

    NARCIS (Netherlands)

    Marcelis, L.F.M.; Pascale, De S.

    2009-01-01

    Strategies for improving greenhouse crop production should target both developing advanced technological systems and designing improved plants. Based on greenhouse experiments, crop models and biotechnological tools, this paper will discuss the physiology of plant-greenhouse interactions. It is disc

  13. Mechanisms of impact of greenhouse gases on the Earth's ozone layer in the Polar Regions

    Science.gov (United States)

    Zadorozhny, Alexander; Dyominov, Igor

    A numerical 2-D zonally averaged interactive dynamical radiative-photochemical model of the atmosphere including aerosol physics is used to examine the impact of the greenhouse gases CO2, CH4, and N2O on the future long-term changes of the Earth's ozone layer, in particular on its expected recovery after reduction of anthropogenic discharges of chlorine and bromine compounds into the atmosphere. The model allows calculating self-consistently diabatic circu-lation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the North to South Poles, as well as distribution of sulphate aerosol particles and polar strato-spheric clouds (PSCs) of types I and II. The scenarios of expected changes of the anthropogenic pollutants for the period from 1980 through 2050 are taken from Climate Change 2001. The processes, which determine the influence of anthropogenic growth of atmospheric abun-dance of the greenhouse gases on the long-term changes of the Earth's ozone layer in the Polar Regions, have been studied in details. Expected cooling of the stratosphere caused by increases of greenhouse gases, most importantly CO2, essentially influences the ozone layer by two ways: through temperature dependencies of the gas phase reaction rates and through enhancement of polar ozone depletion via increased PSC formation. The model calculations show that a weak-ness in efficiencies of all gas phase catalytic cycles of the ozone destruction due to cooling of the stratosphere is a dominant mechanism of the impact of the greenhouse gases on the ozone layer in Antarctic as well as at the lower latitudes. This mechanism leads to a significant acceleration of the ozone layer recovery here because of the greenhouse gases growth. On the contrary, the mechanism of the impact of the greenhouse gases on the ozone through PSC modification be-gins to be more effective in Arctic in comparison with the gas phase mechanism in springs after about 2020, which leads to retard

  14. Economic growth and greenhouse gas emissions

    Energy Technology Data Exchange (ETDEWEB)

    Ansuategi, Alberto [Environment Department, University of York, York (United Kingdom); Escapa, Marta [Foundations of Economic Analysis Department, University of the Basque Country, Bilbao (Spain)

    2002-01-01

    Recent empirical research has examined the relationship between certain indicators of environmental degradation and income, concluding that in some cases an inverted U-shaped relationship, which has been called an environmental Kuznets curve (EKC), exists between these variables. Unfortunately, this inverted U-shaped relationship does not hold for greenhouse gas emissions. One explanation of the absence of EKC-like behavior in greenhouse gas emissions is that greenhouse gases are special pollutants that create global, not local, disutility. But the international nature of global warming is not the only reason that prevents de-linking greenhouse gas emissions from economic growth. The intergenerational nature of the negative impact of greenhouse gas emissions may have also been an important factor preventing the implementation of greenhouse gas abatement measures in the past. In this paper we explore the effect that the presence of intergenerational spillovers has on the emissions-income relationship. We use a numerically calibrated overlapping generations model of climate-economy interactions. We conclude that: (1) the intertemporal responsibility of the regulatory agency, (2) the institutional capacity to make intergenerational transfers and (3) the presence of intergenerationally lagged impact of emissions constitute important determinants of the relationship between economic growth and greenhouse gas emissions.

  15. The greenhouse gases

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, R.

    1987-01-01

    The main greenhouse gases are carbon dioxide, methane, nitrous oxide, CFCs and ozone. They are greenhouse gases as they absorb radiation from the Earth and thus impede its emission back to space. CO{sub 2} is responsible for about half the enhanced greenhouse effect. A global warming of only a few degrees would have a profound effect on climate. Increased levels of CO{sub 2} promote plant growth, but may not benefit agriculture overall. Sea levels may rise. It is difficult to predict the effects of global warming in society. It would be possible to reduce the scale of the greenhouse effect by energy conservation, using alternative energy sources, and possibly by capturing CO{sub 2} from fossil fuel power stations and disposing of it on the ocean floor. 13 refs., 19 figs., 1 tab.

  16. GEOTHERMAL GREENHOUSING IN TURKEY

    Directory of Open Access Journals (Sweden)

    Sedat Karaman

    2016-07-01

    Full Text Available Use of renewable energy resources should be brought forward to reduce heating costs of greenhouses and to minimize the use of ever-depleting fossil fuels. Geothermal energy not only provides the heat required throughout plant growth, but also allow a year-long production. Geothermal resources with several other benefits therefore play significant role in agricultural activities. With regard to geothermal potential and implementation, Turkey has the 7th place in the world and the 1st place in Europe. Majority of country geothermal resources is used in greenhouse heating. The size of geothermal greenhouses increased 5 folds during the last decade and reached to 2500 decare. In this study, current status of geothermal greenhousing of Turkey was presented; problems and possible solutions were discussed.

  17. Automatic Intelligent Management System of the Temperature and Humidity and Soil Moisture for the Vegetable Greenhouse%蔬菜大棚温湿度和土壤水分自动智能管理系统

    Institute of Scientific and Technical Information of China (English)

    孔国利; 席红旗

    2015-01-01

    针对蔬菜大棚温湿度和土壤水分控制难的问题,采用远距离无线串口透传技术设计了自动智能管理系统,主要由温湿度监控节点、土壤水分监控节点和管理主机组成。监控节点利用处理器 STM32 F103作为控制核心而设计,被均匀布置在大棚的各个区域,通过传感器 AM2302和 SM2802 M 分别采集大棚温湿度和土壤含水率,通过无线串口透传模块E17-TTL100-SMA发送到管理主机。管理主机上运行着采用 C#专业设计的管理软件,自动将接收到的数据进行处理、分析和显示,并存储在数据库SQL Server 2008中,如超出了预设的作物最佳生长范围,根据系统设定自动控制风机和灌溉管道阀开关进行调节。通过对西红柿大棚的实验表明:该系统实现了大棚温度湿度和土壤水分的实时智能管理,大大降低了管理者的劳动强度。%For the temperature, humidity and soil moisture control, the long-distance wireless serial transmission technolog is used to design an intelligent management system, which is composed of temperature and humidity monitoring nodes, soil moisture monitoring nodes and the management host computer.The monitoring nodes use the controller STM32F103 as the control core, and are distributed in different regions of greenhouse to collect the greenhouse tempera-ture and humidity and soil moisture information by the sensor AM2302 and SM2802 M, and send them to management host through the wireless serial transmission module through E17-TTL100-SMA.The management host is running the professional management software designed by C#, which can automaticly process, analyze and display the received data, and store it in a database SQL Server2008.According to the system settings, if the data is beyond the pre-set best range for the crop, it can automatically control the fan and the irrigation pipeline switch to adjust.The tomato greenhouse ex-periments show that the

  18. Temperature dependence of electronic heat capacity in Holstein model

    CERN Document Server

    Fialko, N S; Lakhno, V D

    2015-01-01

    The dynamics of charge migration was modeled to calculate temperature dependencies of its thermodynamic equilibrium values such as energy and electronic heat capacity in homogeneous adenine fragments. The energy varies from nearly polaron one at T~0 to midpoint of the conductivity band at high temperatures. The peak on the graph of electronic heat capacity is observed at the polaron decay temperature.

  19. THE TWO-LEVEL MODEL AT FINITE-TEMPERATURE

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, A.L.

    1980-07-01

    The finite-temperature HFB cranking equations are solved for the two-level model. The pair gap, moment of inertia and internal energy are determined as functions of spin and temperature. Thermal excitations and rotations collaborate to destroy the pair correlations. Raising the temperature eliminates the backbending effect and improves the HFB approximation.

  20. Auctions for national reallocation of greenhouse gas emission rights and greenhouse gas emission credits at corporate level. A play theoretical and non-cooperative solution for modelling and solving for the problem of reallocation; Auktionen zur nationalen Reallokation von Treibhausgas-Emissionsrechten und Treibhausgas-Emissionsgutschriften auf Unternehmensebene. Ein spieltheoretischer nicht-kooperativer Modellierungs- und Loesungsansatz fuer das Reallokationsproblem

    Energy Technology Data Exchange (ETDEWEB)

    Akca, Naciye

    2008-07-01

    With the organization of auctions on electronic markets, an extensive theoretical and empirical knowledge exists. This is non-specific because auctions and electronic markets without specific context are brought up for discussion. Under this aspect, the author of the contribution under consideration reports on a matrix auction which is best suitable for the auction of greenhouse gas emission rights and greenhouse gas emission credits in the context of a national reallocation. The organization of auctions in the sense of the economical suitability criteria and the non-cooperative play-theoretical modelling of the national reallocation are a formal problem. In order to solve this problem, the modelling technology of extensive games and the partial play perfectionism are consulted as an approach of non-cooperative game theory for sequential plays. The author provides a material problem related procedural model with application of UML activity diagrams (UML = Unified Modeling Language).

  1. Solar greenhouses in Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    Polich, M.

    1981-12-01

    After a discussion of solar greenhouse phenomena and the potential for heat collection and food production, design recommendations are provided for attached heat collecting solar sunspaces and for attached food producing solar greenhouses. Also, design of a single solar structure to maximize heat collection and food production is considered. A method of predicting the performance for attached heat collecting solar sunspaces is given in which the solar savings fraction is calculated. (LEW)

  2. 基于湿帘风机系统温室环境温度测量方法的研究%Methods for measuring air temperature in a pad and fan cooling greenhouse

    Institute of Scientific and Technical Information of China (English)

    王蕊; 须晖; 马健; 李天来

    2011-01-01

    针对湿帘风机温室试验对通过湿帘后空气温度测量困难的问题,设计屏蔽送风式、屏蔽非送风式和非屏蔽式3种测量方法,通过试验对3种测量方式的准确性及误差因素进行分析.结果表明:屏蔽非送风式的测量结果受湿帘液滴附着影响较小,测量结果准确可靠;屏蔽送风式测量值较真实值小,误差范围为0.1~3.2℃;非屏蔽式测量方式容易受到外界环境因素的影响,误差范围一2.7~3.9℃,波动范围较大.%During the operation of pad and fan system for greenhouse cooling, fog wafts appeared inside the greenhouse. If the fog adheres to a sensing part of a thermometer, measurement of air temperature through pad will decrease and cause errors. The study was conducted by three measurement methods which were non-aspirated thermocouple with shelter, aspirated psychrometer and bare thermocouple without the shelter. It was found that the result of the non-aspiratecl thermocouple with shelter provided the most accurate measurement values; the measurement result of the aspirated psychrometer was lower than the actual temperature and the error rang was 0.1 - 3.2 ℃ the measurement of the bare thermocouple was affected by environmental factors easily and the error rang was -2.7- 3.9 ℃.

  3. Design of Distributed Multi-point Temperature Monitoring System in Vegetable Greenhouses%蔬菜大棚分布式多点温度监控系统的设计

    Institute of Scientific and Technical Information of China (English)

    冯荣华; 王强; 叶大鹏; 谢艺鑫

    2016-01-01

    Considering problems of low management efficiency and high administration cost in vegetable greenhouse, a distribu-ted multi-point temperature intelligent monitoring system was designed.This system could realize the goal of multi-point and comprehensive information acquisition, automatic alarm when temperature runs above the threshold or in low voltage state by combi-ning the wireless communication technology with the sensor and upper monitor technology .The result shows that this system is suit-able for the environment parameters monitoring in greenhouse with the features of stable operation, strong real-time performance and high inspection accuracy (97.55%) .%针对蔬菜大棚的管理效率低、管理费用高等问题,设计了分布式多点温度智能监控系统。本系统有效结合无线通信技术、传感器技术、上位机技术,实现了蔬菜大棚温度参数进行多点全方位采集,且具有温度超过阈值、电压不足时自动报警的功能。经过实验表明,该系统工作稳定、监测实时性强、检测精度高(可达到97.55%),可适用于蔬菜大棚中的环境参数监测。

  4. 恒温和温室波动温度下异色瓢虫种群生命表%Life Tables of Harmonia axyridis Pallas Under Laboratory Constant and Greenhouse Fluctuating Temperatures

    Institute of Scientific and Technical Information of China (English)

    赵静; 肖达; 张帆; 王甦

    2015-01-01

    [Objective] The ladybird beetle Harmonia axyridis Pallas is a well-known aphid predator and plays an important role as a biological control agent in its native regions. Life table can provide a comprehensive description of the development, survival, and fecundity of a population. The life history of H. axyridis has been studied using the traditional life table in controlled laboratory conditions. However, when released, H. axyridis were exposed to fluctuating temperatures which can significantly change the biological characteristics of insects. The objective of this study is to build life tables for H. axyridis both at constant temperature in the laboratory and at fluctuating temperatures in the greenhouse, and to facilitate the effective use of this species as a biological control agent.[Method]Developmental, survival, and fecundity rate data were analyzed by using the age-stage, two-sex life table under laboratory and greenhouse conditions and the significant differences were compared with t-tests at a 5%significance level by SPSS17.0. Means and standard errors of population parameters were calculated by using the bootstrap method and the significant differences were compared with t-tests by the TWOSEX-MSChart computer program.[Result]H. axyridis at constant temperature in the laboratory developed more quickly in the pre-adult stage and were longer-lived compared with those in the greenhouse. Moreover, significant reductions in survival and reproduction of H. axyridis under greenhouse conditions were observed in the curves of sxj, lx, fx and mx. The life expectancy of H. axyridis decreased gradually with age while the life expectancy were shorter and varied significantly at fluctuating temperatures in the greenhouse. The contribution of an individual to the future population was described by the reproductive value (vxj) which under greenhouse conditions was lower and more varied than that in the laboratory. According to the age-stage, two-sex life table, the

  5. The ice-core record - Climate sensitivity and future greenhouse warming

    Science.gov (United States)

    Lorius, C.; Raynaud, D.; Jouzel, J.; Hansen, J.; Le Treut, H.

    1990-01-01

    The prediction of future greenhouse-gas-warming depends critically on the sensitivity of earth's climate to increasing atmospheric concentrations of these gases. Data from cores drilled in polar ice sheets show a remarkable correlation between past glacial-interglacial temperature changes and the inferred atmospheric concentration of gases such as carbon dioxide and methane. These and other palaeoclimate data are used to assess the role of greenhouse gases in explaining past global climate change, and the validity of models predicting the effect of increasing concentrations of such gases in the atmosphere.

  6. Water temperature modeling in the Garonne River (France

    Directory of Open Access Journals (Sweden)

    Larnier K.

    2010-10-01

    Full Text Available Stream water temperature is one of the most important parameters for water quality and ecosystem studies. Temperature can influence many chemical and biological processes and therefore impacts on the living conditions and distribution of aquatic ecosystems. Simplified models such as statistical models can be very useful for practitioners and water resource management. The present study assessed two statistical models – an equilibrium-based model and stochastic autoregressive model with exogenous inputs – in modeling daily mean water temperatures in the Garonne River from 1988 to 2005. The equilibrium temperature-based model is an approach where net heat flux at the water surface is expressed as a simpler form than in traditional deterministic models. The stochastic autoregressive model with exogenous inputs consists of decomposing the water temperature time series into a seasonal component and a short-term component (residual component. The seasonal component was modeled by Fourier series and residuals by a second-order autoregressive process (Markov chain with use of short-term air temperatures as exogenous input. The models were calibrated using data of the first half of the period 1988–2005 and validated on the second half. Calibration of the models was done using temperatures above 20 °C only to ensure better prediction of high temperatures that are currently at stake for the aquatic conditions of the Garonne River, and particularly for freshwater migrating fishes such as Atlantic Salmon (Salmo salar L.. The results obtained for both approaches indicated that both models performed well with an average root mean square error for observed temperatures above 20 °C that varied on an annual basis from 0.55 °C to 1.72 °C on validation, and good predictions of temporal occurrences and durations of three temperature threshold crossings linked to the conditions of migration and survival of Atlantic Salmon.

  7. Long-term ice sheet-climate interactions under anthropogenic greenhouse forcing simulated with a complex Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Vizcaino, Miren [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); University of California, Department of Geography, Berkeley, CA (United States); Mikolajewicz, Uwe; Maier-Reimer, Ernst [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Groeger, Matthias [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); IFM-GEOMAR, Kiel (Germany); Schurgers, Guy [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Lund University, Department of Physical Geography and Ecosystems Analysis, Lund (Sweden); Winguth, Arne M.E. [Center for Climatic Research, Department of Atmospheric and Oceanic Sciences, Madison (United States)

    2008-11-15

    Several multi-century and multi-millennia simulations have been performed with a complex Earth System Model (ESM) for different anthropogenic climate change scenarios in order to study the long-term evolution of sea level and the impact of ice sheet changes on the climate system. The core of the ESM is a coupled coarse-resolution Atmosphere-Ocean General Circulation Model (AOGCM). Ocean biogeochemistry, land vegetation and ice sheets are included as components of the ESM. The Greenland Ice Sheet (GrIS) decays in all simulations, while the Antarctic ice sheet contributes negatively to sea level rise, due to enhanced storage of water caused by larger snowfall rates. Freshwater flux increases from Greenland are one order of magnitude smaller than total freshwater flux increases into the North Atlantic basin (the sum of the contribution from changes in precipitation, evaporation, run-off and Greenland meltwater) and do not play an important role in changes in the strength of the North Atlantic Meridional Overturning Circulation (NAMOC). The regional climate change associated with weakening/collapse of the NAMOC drastically reduces the decay rate of the GrIS. The dynamical changes due to GrIS topography modification driven by mass balance changes act first as a negative feedback for the decay of the ice sheet, but accelerate the decay at a later stage. The increase of surface temperature due to reduced topographic heights causes a strong acceleration of the decay of the ice sheet in the long term. Other feedbacks between ice sheet and atmosphere are not important for the mass balance of the GrIS until it is reduced to 3/4 of the original size. From then, the reduction in the albedo of Greenland strongly accelerates the decay of the ice sheet. (orig.)

  8. 基于有限元分析的日光温室土质墙体温度场模拟与验证%Simulation and Verification of Greenhouse Soil Wall Temperature Field by FEM Analysis

    Institute of Scientific and Technical Information of China (English)

    侯加林; 王涛; 蒋韬; 王秀峰

    2014-01-01

    It was significant to study the temperature gradient and its change rule for evaluation of heat prevention performance , design and construction of greenhouse wall .The temperature data of greenhouse soil wall in Taian region were measured through multi -point temperature test instrument from December 2012 to February 2013 .The measured results coincided with that obtained through ANSYS FEM simulation .The fur-ther simulation results showed that the temperature of heat release and absorption layer in the wall changed pe -riodically in a day , while that of heat preservation and insulation layer changed smaller .The temperature at the wall bottom was higher , and changed a little in the horizontal direction , which was stable at 10~14℃for long time.The temperature was the highest at the place 0.2 m away from the inner surface of wall , and re-duced gently along the direction of wall thickness; the outer surface of the wall had the lowest temperature . Based on the simulated and measured results , the optimized soil wall of greenhouse in Taian area showed that the minimum thickness should be 2.2 m, including 0~0.5 m of heat release and absorption layer and 1.3~1 .7 m of heat preservation and insulation layer .%研究日光温室墙体中温度梯度及其变化规律对于日光温室墙体的蓄热保温性能分析评价、设计与建造有着重要的意义。2012年12月至2013年2月,采用自制多点温度测试仪,对山东泰安地区日光温室土质墙体的温度进行采集,并与ANSYS有限元模拟结果进行比较,发现温度场实测结果与模拟结果相吻合。进一步模拟结果表明,墙体蓄热/放热层一天中呈周期性变化,保温隔热层随外界温度变化较小,墙体下部温度较高,且在水平方向上温度梯度变化较小,在10~14℃持续时间长且稳定;距墙体内表面0.2 m处温度最高,并沿墙体厚度方向逐渐平缓降低,墙体外表面温度最低。基于模拟结

  9. Influence of spatially-dependent, modeled soil carbon emission factors on life-cycle greenhouse gas emissions of corn and cellulosic ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhangcai; Dunn, Jennifer B.; Kwon, Ho-young; Mueller, Steffen; Wander, Michelle M.

    2016-01-01

    Converting land to biofuel feedstock production incurs changes in soil organic carbon (SOC) that can influence biofuel life-cycle greenhouse gas (GHG) emissions. Estimates of these land use change (LUC) and life-cycle GHG emissions affect biofuels’ attractiveness and eligibility under a number of renewable fuel policies in the U.S. and abroad. Modeling was used to refine the spatial resolution and depth-extent of domestic estimates of SOC change for land (cropland, cropland pasture, grasslands, and forests) conversion scenarios to biofuel crops (corn, corn stover, switchgrass, Miscanthus, poplar, and willow). In most regions, conversions from cropland and cropland pasture to biofuel crops led to neutral or small levels of SOC sequestration, while conversion of grassland and forest generally caused net SOC loss. Results of SOC change were incorporated into the Greenhouse Gases, Regulated Emissions, and Energy use in Transportation (GREET) model to assess their influence on life-cycle GHG emissions for the biofuels considered. Total LUC GHG emissions (g CO2eq MJ-1) were 2.1–9.3 for corn, -0.7 for corn stover, -3.4–12.9 for switchgrass, and -20.1–-6.2 for Miscanthus; these varied with SOC modeling assumptions applied. Extending soil depth from 30 to 100cm affected spatially-explicit SOC change and overall LUC GHG emissions; however the influence on LUC GHG emissions estimates were less significant in corn and corn stover than cellulosic feedstocks. Total life-cycle GHG emissions (g CO2eq MJ-1, 100cm) were estimated to be 59–66 for corn ethanol, 14 for stover ethanol, 18-26 for switchgrass ethanol, and -0.6–-7 for Miscanthus ethanol.

  10. A concise wall temperature model for DI Diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Torregrosa, A.; Olmeda, P.; Degraeuwe, B. [CMT-Motores Termicos, Universidad Politecnica de Valencia (Spain); Reyes, M. [Centro de Mecanica de Fluidos y Aplicaciones, Universidad Simon Bolivar (Venezuela)

    2006-08-15

    A concise resistor model for wall temperature prediction in diesel engines with piston cooling is presented here. The model uses the instantaneous in-cylinder pressure and some usually measured operational parameters to predict the temperature of the structural elements of the engine. The resistor model was adjusted by means of temperature measurements in the cylinder head, the liner and the piston. For each model parameter, an expression as a function of the engine geometry, operational parameters and material properties was derived to make the model applicable to other similar engines. The model predicts well the cylinder head, liner and piston temperature and is sensitive to variations of operational parameters such as the start of injection, coolant and oil temperature and engine speed and load. (author)

  11. Modelling of tandem cell temperature coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, D.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    This paper discusses the temperature dependence of the basic solar-cell operating parameters for a GaInP/GaAs series-connected two-terminal tandem cell. The effects of series resistance and of different incident solar spectra are also discussed.

  12. Drinking Water Temperature Modelling in Domestic Systems

    NARCIS (Netherlands)

    Moerman, A.; Blokker, M.; Vreeburg, J.; Van der Hoek, J.P.

    2014-01-01

    Domestic water supply systems are the final stage of the transport process to deliver potable water to the customers’ tap. Under the influence of temperature, residence time and pipe materials the drinking water quality can change while the water passes the domestic drinking water system. According

  13. Can a regional climate model reproduce observed extreme temperatures?

    Directory of Open Access Journals (Sweden)

    Peter F. Craigmile

    2013-10-01

    Full Text Available Using output from a regional Swedish climate model and observations from the Swedish synoptic observational network, we compare seasonal minimum temperatures from model output and observations using marginal extreme value modeling techniques. We make seasonal comparisons using generalized extreme value models and empirically estimate the shift in the distribution as a function of the regional climate model values, using the Doksum shift function. Spatial and temporal comparisons over south central Sweden are made by building hierarchical Bayesian generalized extreme value models for the observed minima and regional climate model output. Generally speaking the regional model is surprisingly well calibrated for minimum temperatures. We do detect a problem in the regional model to produce minimum temperatures close to 0◦C. The seasonal spatial effects are quite similar between data and regional model. The observations indicate relatively strong warming, especially in the northern region. This signal is present in the regional model, but is not as strong.

  14. Cascade recursion models of computing the temperatures of underground layers

    Institute of Scientific and Technical Information of China (English)

    HAN; Liqun; BI; Siwen; SONG; Shixin

    2006-01-01

    An RBF neural network was used to construct computational models of the underground temperatures of different layers, using ground-surface parameters and the temperatures of various underground layers. Because series recursion models also enable researchers to use above-ground surface parameters to compute the temperatures of different underground layers, this method provides a new way of using thermal infrared remote sensing to monitor the suture zones of large areas of blocks and to research thermal anomalies in geologic structures.

  15. 3D subsurface temperature model of Europe for geothermal exploration

    NARCIS (Netherlands)

    Limberger, J.; Wees, J.D. van

    2014-01-01

    For the assessment of geothermal resources in Europe we constructed a digital 3D temperature model of the European crust and sedimentary basins, incorporating publicly available temperature data. Using European crustal thickness models and indirect parameters such as surface heat flow measurements,

  16. 3D subsurface temperature model of Europe for geothermal exploration

    NARCIS (Netherlands)

    Limberger, J.; Wees, J.D. van

    2014-01-01

    For the assessment of geothermal resources in Europe we constructed a digital 3D temperature model of the European crust and sedimentary basins, incorporating publicly available temperature data. Using European crustal thickness models and indirect parameters such as surface heat flow measurements,

  17. A physically based analytical spatial air temperature and humidity model

    Science.gov (United States)

    Yang Yang; Theodore A. Endreny; David J. Nowak

    2013-01-01

    Spatial variation of urban surface air temperature and humidity influences human thermal comfort, the settling rate of atmospheric pollutants, and plant physiology and growth. Given the lack of observations, we developed a Physically based Analytical Spatial Air Temperature and Humidity (PASATH) model. The PASATH model calculates spatial solar radiation and heat...

  18. Green Granary Temperature Control System Modeling and Simulation

    Science.gov (United States)

    Shi, Qingsheng

    As an important link of food production and distribution process, Granary's temperature control performance seriously affects the food quality and storage costs. Based on the analysis of granary components, granary temperature control model is established. The simulation results show the validity of established model.

  19. 低功耗农业大棚温湿度测量仪设计%Design of Agricultural Greenhouse Temperature and Humidity Measuring Instrument of Low Power Consumption

    Institute of Scientific and Technical Information of China (English)

    陈树成; 杨志勇; 王建佳

    2014-01-01

    The low-power temperature and humidity measuring instrument is designed , according to the actual need of agricultural greenhouse temperature and humidity control . MSP430 F427 connects temperature and humidity sensor SHT10 , collects the temperature and humidity inside the agricultural greenhouse , then displays the real-time measure-ment result on the LCD screen and stores the measurement result .The measuring instrument is Lithium battery-powered , it can work continuously and stably for six months or more by using a single fully charged Lithium battery , combined with the low-power sleep mode of MSP 430 F427 and timing off of sensor SHT 10 , while the solar charging function can be ex-tended to the system .The article shows the block diagram of the design and gives a detailed description of the tempera -ture and humidity acquisition circuit , USB interface communication circuit , segment LCD circuit , Lithium battery power supply circuit and the other hardware circuit design , and then gives system software program flow chart .Tests show that temperature and humidity measuring instrument can collect the temperature and humidity data inside the greenhouse accu -rately , provide an adequate basis for arranging agricultural production reasonably .%根据农业大棚温湿度控制的实际需要,设计了基于 MSP430 F427的低功耗温湿度测量仪。MSP430 F427连接温湿度传感器SHT10,对农业大棚内的温湿度进行采集,将测量的结果在液晶屏上实时显示,并将数据进行存储。测量仪采用锂电池供电,结合 MSP430 F427的低功耗睡眠模式与传感器 SHT10的定时断电,单节锂电池充满电后能使测量仪连续稳定地工作6个月以上,并且系统可扩展太阳能充电功能。同时,给出了设计的结构框图,详细描述了温湿度采集电路、USB 接口通讯电路、段式液晶显示电路和锂电池供电电路等硬件电路设计,最后给出了系统软件程序流程图

  20. Effects of Sub-low Temperature and Potassium Fertilizer on Photosynthesis and Fruit Quality of Greenhouse Tomato%亚低温及钾肥对温室番茄光合作用和品质的影响

    Institute of Scientific and Technical Information of China (English)

    李俊; 李建明; 胡晓辉; 张大龙; 徐菲; 赵志华; 宋丹

    2012-01-01

    以‘金棚10号’番茄为试验材料,采用盆栽方法,研究了温度与钾肥交互作用对温室盆栽番茄光合作用和品质的影响,为合理施用钾肥提高番茄生长发育过程中抵抗亚低温乃至低温耐性提供理论依据.结果显示:(1)与常温下正常栽培相比,亚低温使番茄植株生长发育迟缓,花序数、叶片数、节间距、叶绿素含量、净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、气孔导度、水分利用效率、单果重及品质显著下降,气孔限制值升高.(2)增施一定量的钾肥能够显著提高亚低温下温室番茄的花序数、叶片数、节间距、叶绿素含量、光合作用、番茄单果重和品质,缓解了亚低温胁迫对温室番茄的伤害.(3)亚低温胁迫下,单株钾肥用量为18.54g时对番茄植株受到亚低温胁迫伤害的缓解效果最佳,少施或者多施都不利于亚低温下番茄植株的正常生长发育.研究表明,亚低温条件下,增施适量的钾肥能有效提高番茄抵抗亚低温胁迫能力,有利于番茄植株的生长和果实品质的提高.%A potted experiment was carried out about tomato of 'Jinpeng No, 10' in temperature and potassium fertilizer interaction to explore the effects on photosynthesis and quality in greenhouse. The results show that,compared with the normal temperature, the sub-low temperature keeps the greenhouse tomatoes grow slowly,and ni flowers number, leaves number, internodal length, chlorophyll content, net photosyn-thetic rate,stomatal conductance, the intercellular CO2 concentration,transpiration rate,stomatal conductance, water use efficiency,weight and quality decreased obviously,and stomatal limitation increase. But if add a certain amount of potassium fertilizer,it can remit the harm of the greenhouse tomatoes,and improve flowers number,leaves number,internodal length,chlorophyll content 1 photosynthesis,tomato fruit weight and quality under the sub-low temperature, Under the

  1. Temperature Calculations in the Coastal Modeling System

    Science.gov (United States)

    2017-04-01

    sediment can be controlled by the density-driven flow and mixing. Temperature can alter the water physical environment that impacts marine organisms ...survey station locations. In application of the CMS to the Corrotoman River, a quadtree grid system was developed to discretize the computational...601-634-2840; fax: 601-634-3080) of the U.S. Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL). The CIRP

  2. Refined Modeling of Water Temperature and Salinity in Coastal Areas

    Institute of Scientific and Technical Information of China (English)

    SHEN Yongming; ZHENG Yonghong; QIU Dahong

    2000-01-01

    The prediction of water temperature and salinity in coastal areas is one of the essential tasks in water quality control and management. This paper takes a refined forecasting model of water temperature and salinity in coastal areas as a basic target. Based on the Navier-Stokes equation and k- turbulence model, taking the characteristics of coastal areas into account, a refined model for water temperatureand salinity in coastal areas has been developed to simulate the seasonal variations of water temperatureand salinity fields in the Hakata Bay, Japan. The model takes into account the effects of a variety ofhydrodynamic and meteorological factors on water temperature and salinity. It predicts daily fluctuations in water temperature and salinity at different depths throughout the year. The model has been calibrated well against the data set of historical water temperature and salinity observations in the Hakata Bay,Japan.

  3. Modeling, Prediction, and Control of Heating Temperature for Tube Billet

    Directory of Open Access Journals (Sweden)

    Yachun Mao

    2015-01-01

    Full Text Available Annular furnaces have multivariate, nonlinear, large time lag, and cross coupling characteristics. The prediction and control of the exit temperature of a tube billet are important but difficult. We establish a prediction model for the final temperature of a tube billet through OS-ELM-DRPLS method. We address the complex production characteristics, integrate the advantages of PLS and ELM algorithms in establishing linear and nonlinear models, and consider model update and data lag. Based on the proposed model, we design a prediction control algorithm for tube billet temperature. The algorithm is validated using the practical production data of Baosteel Co., Ltd. Results show that the model achieves the precision required in industrial applications. The temperature of the tube billet can be controlled within the required temperature range through compensation control method.

  4. Solar greenhouse training project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Davis, L.; Kensil, D.; Lazar, B.; Yanda, B.; Yanda, S.

    1979-04-01

    The goals of this project were: (1) To train twenty teams, each from a different region, to organize and run workshops to build inexpensive, practical solar greenhouses. (2) To help create working solar greenhouse experts in the field available to respond to their community's needs. (3) To establish a national model program for solar greenhouse construction workshops. (4) To determine whether the barn-raising style used in the greenhouse construction workshops could be taught in the format of a 3 1/2 day seminar with a follow-up workshop. (5) To determine whether the audio-visual exhibit and printed materials used in the seminar were effective. (MOW)

  5. Natural ventilation of large multi-span greenhouses

    NARCIS (Netherlands)

    Jong, de T.

    1990-01-01

    In this thesis the ventilation of large multi-span greenhouses caused by wind and temperature effects is studied. Quantification of the ventilation is important to improve the control of the greenhouse climate.

    Knowledge of the flow characteristics of the one-side-mounted windows of

  6. The greenhouse effect; L'effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    Simulations used by the climatologists forecast an increase of the world average temperature of 2 degrees between 1990 and 2100, resulting from the greenhouse effect gases. This paper gives examples of consequences of this climatic warming and presents the international agreements to fight against the greenhouse effect gases decided at Rio, Kyoto and, Buenos Aires. (A.L.B.)

  7. A model of evaluating the pseudogap temperature for high-temperature superconductors

    Indian Academy of Sciences (India)

    Islam M R; Maruf H M A R; Chowdhury F-U-Z

    2016-04-01

    We have presented a model of evaluating the pseudogap temperature for high temperature superconductors using paraconductivity approach. The theoretical analysis is based on the crossing point technique of the conductivity expressions. The pseudogap temperature T $^∗$ is found to depend on dimension and is calculated for 2D and 3D superconducting samples. Numerical calculation is given in favour of the YBCO and doped SmFeAsO$_{1−x}$ samples.

  8. Effect of Flux Adjustments on Temperature Variability in Climate Models

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, P.; Bell, J.; Covey, C.; Sloan, L.

    1999-12-27

    It has been suggested that ''flux adjustments'' in climate models suppress simulated temperature variability. If true, this might invalidate the conclusion that at least some of observed temperature increases since 1860 are anthropogenic, since this conclusion is based in part on estimates of natural temperature variability derived from flux-adjusted models. We assess variability of surface air temperatures in 17 simulations of internal temperature variability submitted to the Coupled Model Intercomparison Project. By comparing variability in flux-adjusted vs. non-flux adjusted simulations, we find no evidence that flux adjustments suppress temperature variability in climate models; other, largely unknown, factors are much more important in determining simulated temperature variability. Therefore the conclusion that at least some of observed temperature increases are anthropogenic cannot be questioned on the grounds that it is based in part on results of flux-adjusted models. Also, reducing or eliminating flux adjustments would probably do little to improve simulations of temperature variability.

  9. Fundamental Thermodynamic Model for Analysis of Stream Temperature Data

    Science.gov (United States)

    Davis, L.; Reiter, M.; Groom, J.; Dent, L.

    2012-12-01

    Stream temperature is a critical aquatic ecosystem parameter and has been extensively studied for many years. Complex models have been built as a way to understand stream temperature dynamics and estimate the magnitude of anthropogenic influences on temperature. These models have proven very useful in estimating the relative contribution of various thermal energy sources to the stream heat budget and how management can alter the heat budget. However, the large number of measured or estimated input parameters required by such models makes their application to the analysis of specific stream temperature data difficult when the necessary input data is not readily available. To gain insight into the physical processes governing stream temperature behavior in forested streams we analyzed data based on fundamental thermodynamic concepts. The dataset we used is from a recent multi-year study on the effects of timber harvest on stream temperature in the Oregon Coast Range. From the hourly temperature data we extracted time-averaged diurnal heating and cooling rates. Examining the data in this context allowed us to qualitatively assess changes in the relative magnitude of stream temperature (T), stream equilibrium temperature (Teq), and effective heat transfer coefficient (h) across years and treatments. A benefit of analyzing the data in this way is that it separates the influence of timber harvest on stream temperature from that of climate variation. To categorize longitudinal temperature behaviors before and after timber harvest we developed a data-event matrix which specifies qualitative constraints (i.e., what is physically possible for T, Teq and h) for a given set of observed stream temperature responses. We then analyzed data from 18 different streams to categorize the temperature response to management. Understanding stream temperature dynamics using fundamental thermodynamic concepts provides insight into the processes governing stream temperature and the pathways

  10. 基于物联网的日光温室低温灾害监测预警技术及应用%Forewarning technology and application for monitoring low temperature disaster in solar greenhouses based on internet of things

    Institute of Scientific and Technical Information of China (English)

    黎贞发; 王铁; 宫志宏; 李宁

    2013-01-01

      为减少冬春季由于大风强降温、连阴天造成的低温灾害对日光温室生产造成的影响,该文介绍利用物联网技术,集成开发一套包括日光温室小气候与生态环境监测网络、数据实时采集与无线传输、低温灾害监测与预警发布、远程加温控制于一体的技术方法。该方法通过构建具有统一入口的分布式信息管理系统,实现对不同传感器生产厂家设备的兼容及多个监测站的组网;以嵌入式 GIS 组件库作为开发平台,使数据接收软件有较强的空间显示与分析功能。基于对典型日光温室小气候观测数据与作物生长临界指标,利用逐步回归及神经网络建模,获得土围护和砖维护结构日光温室低温预警指标。利用手机短信、电子显示屏、网站等多媒体发布低温预警服务,并采用远程智能控制方式实现对温室定时加温。该项技术有效地解决了天津地区日光温室低温灾害监测和预警需要,提高设施农业园区管理水平和应对灾害能力。%The Internet of Things has been wildly used in solar greenhouse. Most applications focus on facilities modern greenhouse environment monitoring and regulation, product traceability, and pest remote diagnostics. In fact, facility agriculture uses different methods to change microclimate in greenhouse to help crop grow anti –seasonally. This study focused on the Internet of Things (IOT) application in reducing the influence of low temperature disaster on solar greenhouse production in North China caused by strong cooling and successive overcast weather in winter and spring. We installed several sensors in greenhouse including air temperature, relative humidity, soil temperature, radiation (or light intensity), crop camera platform with synchronization photography, which composed the sensing layer of IOT. The equipments transferred data every 10 minutes to the server in our office. An

  11. Numerical modeling of temperature distributions within the neonatal head.

    Science.gov (United States)

    Van Leeuwen, G M; Hand, J W; Lagendijk, J J; Azzopardi, D V; Edwards, A D

    2000-09-01

    Introduction of hypothermia therapy as a neuroprotection therapy after hypoxia-ischemia in newborn infants requires appraisal of cooling methods. In this numerical study thermal simulations were performed to test the hypothesis that cooling of the surface of the cranium by the application of a cooling bonnet significantly reduces deep brain temperature and produces a temperature differential between the deep brain and the body core. A realistic three-dimensional (3-D) computer model of infant head anatomy was used, derived from magnetic resonance data from a newborn infant. Temperature distributions were calculated using the Pennes heatsink model. The cooling bonnet was at a constant temperature of 10 degrees C. When modeling head cooling only, a constant body core temperature of 37 degrees C was imposed. The computed result showed no significant cooling of the deep brain regions, only the very superficial regions of the brain are cooled to temperatures of 33-34 degrees C. Poor efficacy of head cooling was still found after a considerable increase in the modeled thermal conductivities of the skin and skull, or after a decrease in perfusion. The results for the heatsink thermal model of the infant head were confirmed by comparison of results computed for a scaled down adult head, using both the heatsink description and a discrete vessel thermal model with both anatomy and vasculature obtained from MR data. The results indicate that significant reduction in brain temperature will only be achieved if the infant's core temperature is lowered.

  12. Greenhouse effect due to chlorofluorocarbons - Climatic implications

    Science.gov (United States)

    Ramanathan, V.

    1975-01-01

    The infrared bands of chlorofluorocarbons and chlorocarbons enhance the atmospheric greenhouse effect. This enhancement may lead to an appreciable increase in the global surface temperature if the atmospheric concentrations of these compounds reach values of the order of 2 parts per billion.

  13. Short Wave upwelling Radiative Flux (SWupRF) within NIR range for the selected greenhouse wavelength bands of O2, H2O, CO2 and CH4 by Argus 1000 along with GENSPECT line by line radiative transfer model

    CERN Document Server

    Siddiqui, Rehan; Salem, Naif Al; Quine, Brendan M

    2016-01-01

    This new study develops an algorithm for Short Wave upwelling Radiative Flux (SWupRF) for the spectral variations within near infrared (NIR) from 1100 to 1700 nm wavelength band based on remote sensing data set of Argus 1000 micro-spectrometer observations. We calculate the SWupRF by investigating the total radiative flux due to O2, H2O, CO2 and CH4 and also by the individual gas within the selected wavelength bands of interest. A GENSPECT synthetic line by line radiative transfer model is applied to perform radiative transfer simulations to calculate the radiative flux by varying surface albedo, mixing ratios of the selected greenhouse gases, surface temperature, solar sun and zenith angles with different latitude and longitude of the instrument. Finally, the SWupRFsyn estimated from GENSPECT was compared with SWupRFobs from Argus 1000 over a period of four years (2009 and 2013) covering all seasons. We calculate and compare both the synthetic and real measured observed data set. The synthetic model gives SW...

  14. Modelling temperature and concentration dependent solid/liquid interfacial energies

    Science.gov (United States)

    Lippmann, Stephanie; Jung, In-Ho; Paliwal, Manas; Rettenmayr, Markus

    2016-01-01

    Models for the prediction of the solid/liquid interfacial energy in pure substances and binary alloys, respectively, are reviewed and extended regarding the temperature and concentration dependence of the required thermodynamic entities. A CALPHAD-type thermodynamic database is used to introduce temperature and concentration dependent melting enthalpies and entropies for multicomponent alloys in the temperature range between liquidus and solidus. Several suitable models are extended and employed to calculate the temperature and concentration dependent interfacial energy for Al-FCC with their respective liquids and compared with experimental data.

  15. The enhanced greenhouse signal versus natural variations in observed climate time series: a statistical approach

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwiese, C.D. [J.W. Goethe Univ., Frankfurt (Germany). Inst. for Meteorology and Geophysics

    1995-12-31

    It is a well-known fact that human activities lead to an atmospheric concentration increase of some IR-active trace gases (greenhouse gases GHG) and that this influence enhances the `greenhouse effect`. However, there are major quantitative and regional uncertainties in the related climate model projections and the observational data reflect the whole complex of both anthropogenic and natural forcing of the climate system. This contribution aims at the separation of the anthropogenic enhanced greenhouse signal in observed global surface air temperature data versus other forcing using statistical methods such as multiple (multiforced) regressions and neural networks. The competitive natural forcing considered are volcanic and solar activity, in addition the ENSO (El Nino/Southern Oscillation) mechanism. This analysis will be extended also to the NAO (North Atlantic Oscillation) and anthropogenic sulfate formation in the troposphere

  16. Modeling impacts of alternative practices on net global warming potential and greenhouse gas intensity from rice-wheat annual rotation in China.

    Directory of Open Access Journals (Sweden)

    Jinyang Wang

    Full Text Available BACKGROUND: Evaluating the net exchange of greenhouse gas (GHG emissions in conjunction with soil carbon sequestration may give a comprehensive insight on the role of agricultural production in global warming. MATERIALS AND METHODS: Measured data of methane (CH(4 and nitrous oxide (N(2O were utilized to test the applicability of the Denitrification and Decomposition (DNDC model to a winter wheat - single rice rotation system in southern China. Six alternative scenarios were simulated against the baseline scenario to evaluate their long-term (45-year impacts on net global warming potential (GWP and greenhouse gas intensity (GHGI. PRINCIPAL RESULTS: The simulated cumulative CH(4 emissions fell within the statistical deviation ranges of the field data, with the exception of N(2O emissions during rice-growing season and both gases from the control treatment. Sensitivity tests showed that both CH(4 and N(2O emissions were significantly affected by changes in both environmental factors and management practices. Compared with the baseline scenario, the long-term simulation had the following results: (1 high straw return and manure amendment scenarios greatly increased CH(4 emissions, while other scenarios had similar CH(4 emissions, (2 high inorganic N fertilizer increased N(2O emissions while manure amendment and reduced inorganic N fertilizer scenarios decreased N(2O emissions, (3 the mean annual soil organic carbon sequestration rates (SOCSR under manure amendment, high straw return, and no-tillage scenarios averaged 0.20 t C ha(-1 yr(-1, being greater than other scenarios, and (4 the reduced inorganic N fertilizer scenario produced the least N loss from the system, while all the scenarios produced comparable grain yields. CONCLUSIONS: In terms of net GWP and GHGI for the comprehensive assessment of climate change and crop production, reduced inorganic N fertilizer scenario followed by no-tillage scenario would be advocated for this specified

  17. Evaluation of Temperature and Precipitation in Coupled Regional Climate Model Simulations

    Science.gov (United States)

    Fischer, Andreas M.; Weigel, Andreas P.; Liniger, Mark A.; Buser, Christoph; Appenzeller, Christof

    2010-05-01

    Climate change is expected to have major impacts on society and ecosystems during the upcoming decades. The exact quantification of the climate change signal to be expected, however, is still associated with many uncertainties. For an atmosphere-ocean general circulation model (AOGCM) uncertainties in projecting future climate arise from a number of different sources: uncertainties in physical process understanding and model formulation, natural climate variability, and the amount of future anthropogenic greenhouse gas levels in the atmosphere. When analyzing AOGCM-driven regional climate model (RCM) simulations, which are often applied to provide local climate change information to the impacts community and policy makers, a further level of model uncertainty is introduced. An important step towards quantifying model uncertainty is the analysis of systematic model biases and of the the inter-model spread of the climate change signals obtained. Here, we compare RCM simulations of temperature and precipitation from the FP6-ENSEMBLES project among each other and against observations over Europe, and in greater detail over Switzerland. The RCMs (at 25 km horizontal resolution) were driven by AOGCMs and run in transient mode over the period 1950 to 2050 based on the A1B emission scenario. Some of the RCMs were forced by the same AOGCM, hence allowing to study the spread of different RCMs under the same boundary conditions. Climate change over Switzerland is assessed for the period 2021-50 as seasonal means over distinct climatic regions. The coupled RCM-GCM models exhibit remarkably large systematic biases in temperature and precipitation. Over selected European regions the absolute temperature bias can be as high as 5 K, although the annual cycle is relatively well reproduced. In general, the models simulate too wet conditions with biases of 50 - 100 % above observations during wintertime. Over Switzerland the interannual variability is generally overestimated

  18. Regression analysis in modeling of air surface temperature and factors affecting its value in Peninsular Malaysia

    Science.gov (United States)

    Rajab, Jasim Mohammed; Jafri, Mohd. Zubir Mat; Lim, Hwee San; Abdullah, Khiruddin

    2012-10-01

    This study encompasses air surface temperature (AST) modeling in the lower atmosphere. Data of four atmosphere pollutant gases (CO, O3, CH4, and H2O) dataset, retrieved from the National Aeronautics and Space Administration Atmospheric Infrared Sounder (AIRS), from 2003 to 2008 was employed to develop a model to predict AST value in the Malaysian peninsula using the multiple regression method. For the entire period, the pollutants were highly correlated (R=0.821) with predicted AST. Comparisons among five stations in 2009 showed close agreement between the predicted AST and the observed AST from AIRS, especially in the southwest monsoon (SWM) season, within 1.3 K, and for in situ data, within 1 to 2 K. The validation results of AST with AST from AIRS showed high correlation coefficient (R=0.845 to 0.918), indicating the model's efficiency and accuracy. Statistical analysis in terms of β showed that H2O (0.565 to 1.746) tended to contribute significantly to high AST values during the northeast monsoon season. Generally, these results clearly indicate the advantage of using the satellite AIRS data and a correlation analysis study to investigate the impact of atmospheric greenhouse gases on AST over the Malaysian peninsula. A model was developed that is capable of retrieving the Malaysian peninsulan AST in all weather conditions, with total uncertainties ranging between 1 and 2 K.

  19. Multiaxial Temperature- and Time-Dependent Failure Model

    Science.gov (United States)

    Richardson, David; McLennan, Michael; Anderson, Gregory; Macon, David; Batista-Rodriquez, Alicia

    2003-01-01

    A temperature- and time-dependent mathematical model predicts the conditions for failure of a material subjected to multiaxial stress. The model was initially applied to a filled epoxy below its glass-transition temperature, and is expected to be applicable to other materials, at least below their glass-transition temperatures. The model is justified simply by the fact that it closely approximates the experimentally observed failure behavior of this material: The multiaxiality of the model has been confirmed (see figure) and the model has been shown to be applicable at temperatures from -20 to 115 F (-29 to 46 C) and to predict tensile failures of constant-load and constant-load-rate specimens with failure times ranging from minutes to months..

  20. Modelling of a Multi-Temperature Plasma Composition

    Institute of Scientific and Technical Information of China (English)

    B. Liani; R.Benallal; Z.Bentalha

    2005-01-01

    @@ Knowledge of plasma composition is very important for various plasma applications and prediction of plasma properties. We use the Saha equation and Debye length equation to calculate the non-local thermodynamicequilibrium plasma composition. It has been shown that the model to 2T with T representing the temperature (electron temperature and heavy-particle temperature) described by Chen and Han [J. Phys. D 32 (1999)1711]can be applied for a mixture of gases, where each atomic species has its own temperature, but the model to 4T is more general because it can be applicable to temperatures distant enough of the heavy particles. This can occur in a plasma composed of big- or macro-molecules. The electron temperature Te varies in the range 8000*20000 K at atmospheric pressure.

  1. Monte Carlo grain growth modeling with local temperature gradients

    Science.gov (United States)

    Tan, Y.; Maniatty, A. M.; Zheng, C.; Wen, J. T.

    2017-09-01

    This work investigated the development of a Monte Carlo (MC) simulation approach to modeling grain growth in the presence of non-uniform temperature field that may vary with time. We first scale the MC model to physical growth processes by fitting experimental data. Based on the scaling relationship, we derive a grid site selection probability (SSP) function to consider the effect of a spatially varying temperature field. The SSP function is based on the differential MC step, which allows it to naturally consider time varying temperature fields too. We verify the model and compare the predictions to other existing formulations (Godfrey and Martin 1995 Phil. Mag. A 72 737-49 Radhakrishnan and Zacharia 1995 Metall. Mater. Trans. A 26 2123-30) in simple two-dimensional cases with only spatially varying temperature fields, where the predicted grain growth in regions of constant temperature are expected to be the same as for the isothermal case. We also test the model in a more realistic three-dimensional case with a temperature field varying in both space and time, modeling grain growth in the heat affected zone of a weld. We believe the newly proposed approach is promising for modeling grain growth in material manufacturing processes that involves time-dependent local temperature gradient.

  2. Model-based control of district heating supply temperature

    Energy Technology Data Exchange (ETDEWEB)

    Saarinen, Linn

    2010-11-15

    A model-based control strategy for the supply temperature to a district heating network was tested during three weeks at Idbaecken's CHP plant. The aim was to increase the electricity efficiency by a lower supply temperature, without risking the delivery reliability of heat to the district heating customers. Simulations and tests showed that at high loads, the mean supply temperature could be reduced by 4 deg C and the electricity production could be increased by 2.5%

  3. Statistical Modeling for Wind-Temperature Meteorological Elements in Troposphere

    CERN Document Server

    Virtser, A; Golbraikh, E

    2010-01-01

    A comprehensive statistical model for vertical profiles of the horizontal wind and temperature throughout the troposphere is presented. The model is based on radiosonde measurements of wind and temperature during several years. The profiles measured under quite different atmospheric conditions exhibit qualitative similarity, and a proper choice of the reference scales for the wind, temperature and altitude levels allows to consider the measurement data as realizations of a random process with universal characteristics: means, the basic functions and parameters of standard distributions for transform coefficients of the Principal Component Analysis. The features of the atmospheric conditions are described by statistical characteristics of the wind-temperature ensemble of dimensional reference scales. The high effectiveness of the proposed approach is provided by a similarity of wind - temperature vertical profiles, which allow to carry out the statistical modeling in the low-dimension space of the dimensional ...

  4. Heat propagation models for superconducting nanobridges at millikelvin temperatures

    Science.gov (United States)

    Blois, A.; Rozhko, S.; Hao, L.; Gallop, J. C.; Romans, E. J.

    2017-01-01

    Nanoscale superconducting quantum interference devices (nanoSQUIDs) most commonly use Dayem bridges as Josephson elements to reduce the loop size and achieve high spin sensitivity. Except at temperatures close to the critical temperature T c, the electrical characteristics of these bridges exhibit undesirable thermal hysteresis which complicates device operation. This makes proper thermal analysis an essential design consideration for optimising nanoSQUID performance at ultralow temperatures. However the existing theoretical models for this hysteresis were developed for micron-scale devices operating close to liquid helium temperatures, and are not fully applicable to a new generation of much smaller devices operating at significantly lower temperatures. We have therefore developed a new analytic heat model which enables a more accurate prediction of the thermal behaviour in such circumstances. We demonstrate that this model is in good agreement with experimental results measured down to 100 mK and discuss its validity for different nanoSQUID geometries.

  5. Subsurface temperatures in Denmark – measurements and modelling

    DEFF Research Database (Denmark)

    Balling, N.; Poulsen, Søren Erbs; Bording, Thue Sylvester;

    2014-01-01

    lithologies of different conductivity. Mean geothermal gradients from surface to depths of 1000 to 3000 m are generally between 20 and 30 °C/km. As an example, modelled temperatures for the Gassum geothermal reservoir are shown with temperatures largely between 35 and 90 °C for depths of interest....

  6. Temperature sensitivity of a numerical pollen forecast model

    Science.gov (United States)

    Scheifinger, Helfried; Meran, Ingrid; Szabo, Barbara; Gallaun, Heinz; Natali, Stefano; Mantovani, Simone

    2016-04-01

    Allergic rhinitis has become a global health problem especially affecting children and adolescence. Timely and reliable warning before an increase of the atmospheric pollen concentration means a substantial support for physicians and allergy suffers. Recently developed numerical pollen forecast models have become means to support the pollen forecast service, which however still require refinement. One of the problem areas concerns the correct timing of the beginning and end of the flowering period of the species under consideration, which is identical with the period of possible pollen emission. Both are governed essentially by the temperature accumulated before the entry of flowering and during flowering. Phenological models are sensitive to a bias of the temperature. A mean bias of -1°C of the input temperature can shift the entry date of a phenological phase for about a week into the future. A bias of such an order of magnitude is still possible in case of numerical weather forecast models. If the assimilation of additional temperature information (e.g. ground measurements as well as satellite-retrieved air / surface temperature fields) is able to reduce such systematic temperature deviations, the precision of the timing of phenological entry dates might be enhanced. With a number of sensitivity experiments the effect of a possible temperature bias on the modelled phenology and the pollen concentration in the atmosphere is determined. The actual bias of the ECMWF IFS 2 m temperature will also be calculated and its effect on the numerical pollen forecast procedure presented.

  7. A New Perspective of the Physical Processes Associated with the Clear-Sky Greenhouse Effect over High Latitudes

    Institute of Scientific and Technical Information of China (English)

    Zuohao CAO; Ronald E.STEWART; M.K.YAU

    2004-01-01

    The physical processes associated with the clear-sky greenhouse effect in the presence of water vapor are examined by including surface emissivity in the greenhouse effect formulation, and by introducing a new way to partition physical processes of the greenhouse effect. In this new framework, it is found that the clear-sky greenhouse effect is governed by three physical processes associated with (1) the temperature contrast between the surface and the atmosphere, (2) the interaction between the surface emissivity and the temperature contrast, and (3) the surface emissivity. The importance of the three physical processes is assessed by computing their vertical and spectral variations for the subarctic winter and summer standard atmosphere using the radiation model MODTRAN3 (Moderate Resolution Transmittance code Version 3). The results show that the process associated with the temperature contrast between the surface and the atmosphere dominates over the other two processes in magnitude. The magnitude of this process has substantial variations in the spectral region of 1250 to 1880 cm-1 and in the far infrared region. Due to the low-level temperature inversion over the subarctic winter, there exists a negative contribution to the greenhouse trapping. The seasonal variations are, however, dominated by the processes associated with the interaction between the surface emissivity and the temperature contrast as well as the surface emissivity itself. The magnitudes of these two physical processes contributing to the greenhouse trapping over the subarctic winter are about 7 to 10 times of those over the subarctic summer, whereas the magnitude of the processes associated with the temperature contrast in the subarctic summer is only about 2 times of that in the subarctic winter.

  8. The Greenhouse Effect and Climate Feedbacks

    Science.gov (United States)

    Covey, C.; Haberle, R. M.; McKay, C. P.; Titov, D. V.

    This chapter reviews the theory of the greenhouse effect and climate feedback. It also compares the theory with observations, using examples taken from all four known terrestrial worlds with substantial atmospheres: Venus, Earth, Mars, and Titan. The greenhouse effect traps infrared radiation in the atmosphere, thereby increasing surface temperature. It is one of many factors that affect a world's climate. (Others include solar luminosity and the atmospheric scattering and absorption of solar radiation.) A change in these factors — defined as climate forcing — may change the climate in a way that brings other processes — defined as feedbacks — into play. For example, when Earth's atmospheric carbon dioxide increases, warming the surface, the water vapor content of the atmosphere increases. This is a positive feedback on global warming because water vapor is itself a potent greenhouse gas. Many positive and negative feedback processes are significant in determining Earth's climate, and probably the climates of our terrestrial neighbors.

  9. Blocking layer modeling for temperature analysis of electron transfer ...

    African Journals Online (AJOL)

    Blocking layer modeling for temperature analysis of electron transfer rate in quantum dot sensitized solar cells. ... Journal of Fundamental and Applied Sciences ... of the quantum dots and free energy of system and finally the Marcus equation.

  10. Electronic Modeling and Design for Extreme Temperatures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We are developing CAD tools, models and methodologies for electronics design for circuit operation in extreme environments with focus on very low temperatures...

  11. On the Temperature Dependence of the UNIQUAC/UNIFAC Models

    DEFF Research Database (Denmark)

    Skjold-Jørgensen, Steen; Rasmussen, Peter; Fredenslund, Aage

    1980-01-01

    Local composition models for the description of the properties of liquid mixtures do not in general give an accurate representation of excess Gibbs energy and excess enthalpy simultaneously. The introduction of temperature dependent interaction parameters leads to considerable improvements...

  12. Pemodelan Matematik Kinerja Pengering Surya Efek Rumah Kaca (ERK-Hibrid Menggunakan Rak Berputar secara Vertikal (Mathematical Modeling Performance of Greenhouse Effect (GHE-Hybrid Solar Dryer with a Vertical Rotating Rack

    Directory of Open Access Journals (Sweden)

    Sigit Triwahyudi

    2016-12-01

    Full Text Available This paper presents a performance test and mathematical modeling of greenhouse effect (GHE-Hybrid solar dryer with vertical rotating rack. The dryer consists of a greenhouse dryer (1100 × 860 × 1300 mm with eight rack and additional heating system consists of a flat plate collector (1,04 m2, a hot water storage tank (197 liters and a heat exchanger. To investigate the performance of solar greenhouse dryer, five experimental variation speed of rack were conducted (1, 4, 7, 10 rpm and without rotation. Materials used in the experiment are local cardamom (Amomum cardamomum Wild. Weight of each experiment  about  9 to 10 kg. The average temperature of the hot water storage tank varies from 50.0 to 55.0 °C, drying air  temperature between 38.9 to 45.9 °C, while the relative humidity (RH of drying chamber ranged from 32.1 to 47.4 %. Variation of rotational speed affects on the uniformity of product temperature and water content in each rack drying. At rotation 1 rpm  (experiment II, obtained  as the best conditions (temperature and moisture content are most uniform. Increasing rotational speed of rack causes increasing in standard deviation of  product temperature and moisture content. To simulate the performance of the dryer, mathematical modeling based on heat  and mass transfer and a thin layer drying  approaches were conducted. Equations solved numerically using the finite difference Euler with Visual Basic Application (VBA program on Excel. Validation was conducted by comparing the calculation results of mathematical modeling (data prediction with measurement data (data observation. Criterion validity was determined by  the value of the coefficient of determination (R2, the value of RMSD and MAPD. Mathematical models that have been developed can be described precisely the temperature of the hot water storage tank, temperature of the drying chamber, temperature of the product as well as a moisture content decrease.   ABSTRAK Makalah

  13. Physics of greenhouse effect and convection in warm oceans

    Science.gov (United States)

    Inamdar, A. K.; Ramanathan, V.

    1994-01-01

    Sea surface temperature (SST) in roughly 50% of the tropical Pacific Ocean is warm enough (SST greater than 300 K) to permit deep convection. This paper examines the effects of deep convection on the climatological mean vertical distributions of water vapor and its greenhouse effect over such warm oceans. The study, which uses a combination of satellite radiation budget observations, atmospheric soundings deployed from ships, and radiation model calculations, also examines the link between SST, vertical distribution of water vapor, and its greenhouse effect in the tropical oceans. Since the focus of the study is on the radiative effects of water vapor, the radiation model calculations do not include the effects of clouds. The data are grouped into nonconvective and convective categories using SST as an index for convective activity. On average, convective regions are more humid, trap significantly more longwave radiation, and emit more radiation to the sea surface. The greenhouse effect in regions of convection operates as per classical ideas, that is, as the SST increases, the atmosphere traps the excess longwave energy emitted by the surface and reradiates it locally back to the ocean surface. The important departure from the classical picture is that the net (up minus down) fluxes at the surface and at the top of the atmosphere decrease with an increase in SST; that is, the surface and the surface-troposphere column lose the ability to radiate the excess energy to space. The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST; that of the column is due to a combination of increase in humidity in the entire column and increase in the lapse rate within the lower troposphere. The increase in the vertical distribution of humidity far exceeds that which can be attributed to the temperature dependence of saturation vapor pressure; that is, the tropospheric relative humidity is larger in convective

  14. LEDs for greenhouse lighting

    NARCIS (Netherlands)

    Nederhoff, E.M.

    2010-01-01

    Light Emitting Diodes (LED's) are a promising technology for greenhouse lighting with their efficiency to activate plant photosynthesis potentially higher in red LEDs than in HPS lamps. Due to their particular light colour, LEDs can initiate special effects in plants or steer plant processes and

  15. Innovation in greenhouse engineering

    NARCIS (Netherlands)

    Giacomelli, G.A.; Castilla, N.; Henten, van E.J.; Mears, D.R.; Sase, S.

    2008-01-01

    Innovations in greenhouse engineering are technical developments which help evolve the state-of-the-art in CEA (Controlled Environment Agriculture). They occur in response to the operational demands on the system, and to strategic changes in expectations of the production system. Influential

  16. Innovation in greenhouse engineering

    NARCIS (Netherlands)

    Giacomelli, G.A.; Castilla, N.; Henten, van E.J.; Mears, D.R.; Sase, S.

    2008-01-01

    Innovations in greenhouse engineering are technical developments which help evolve the state-of-the-art in CEA (Controlled Environment Agriculture). They occur in response to the operational demands on the system, and to strategic changes in expectations of the production system. Influential operati

  17. Smarter greenhouse climate control

    NARCIS (Netherlands)

    Nederhoff, E.M.; Houter, G.

    2011-01-01

    Greenhouse operators strive to be as economic as possible with energy. However, investing in fancy energy-saving equipment is often not cost-effective for smaller operations and in climate zones with mild winters. It is possible, though, for many growers to save energy without buying special equipme

  18. Trace Gases, CO2, Climate, and the Greenhouse Effect.

    Science.gov (United States)

    Aubrecht, Gordon J., II

    1988-01-01

    Reports carbon dioxide and other trace gases can be the cause of the Greenhouse Effect. Discusses some effects of the temperature change and suggests some solutions. Included are several diagrams, graphs, and a table. (YP)

  19. Trace Gases, CO2, Climate, and the Greenhouse Effect.

    Science.gov (United States)

    Aubrecht, Gordon J., II

    1988-01-01

    Reports carbon dioxide and other trace gases can be the cause of the Greenhouse Effect. Discusses some effects of the temperature change and suggests some solutions. Included are several diagrams, graphs, and a table. (YP)

  20. Testing empirical relationships between global sea-level and global temperature in long climate model simulations

    Science.gov (United States)

    von Storch, H.; Zorita, E.; Gonzalez-Rouco, F.

    2009-04-01

    Estimations of future global sea-level rise brought about by increasing concentrations of atmospheric greenhouse gases of anthropogenic origin are based on simulations with coarse-resolution global climate models, which imposes some limitations on the skill of future projections because some of the processes that modulate the heat and fresh water flux into may not be adequately represented. To fill this gap, and until more complex climate models are available, some ad-hoc methods have been proposed that link the rise in global average temperature with the global mean sea-level rise. The statistical methods can be calibrated with observations and applied to the future global temperature rise simulated by climate models. This methods can be tested in the virtual reality simulated by global atmosphere.ocean models. Thereby, deficiencies can be identified and improvement suggested. The output of 1000-year long climate model simulation with the coupled atmosphere-ocean model ECHO-G over the past millennium has been used to determine the skill of different predictors to describe the variations of the rate of sea-level change in the simulation. These predictor variables comprise the global mean near-surface temperature, its rate of change with time and the heat-flux into the ocean. It is found that, in the framework of this climate simulation, global mean temperature is not a good predictor for the rate-of-change of sea-level. The correlation between both variables is not stable along the simulations and even its sign changes. A better predictor is the rate-of-change of temperature. Its correlation with the rate-of-change of sea-level is much more stable, it is always positive along the simulation, and there exists a lead-lag relationship between both that can be understood in simple physical terms. The best predictor among those tested is the heat-flux into the ocean. Its correlation is higher and there exists no time lag to the rate-of-change of sea-level, as expected

  1. Modeling the Temperature Effect of Orientations in Residential Buildings

    Directory of Open Access Journals (Sweden)

    Sabahat Arif

    2012-07-01

    Full Text Available Indoor thermal comfort in a building has been an important issue for the environmental sustainability. It is an accepted fact that their designs and planning consume a lot of energy in the modern architecture of 20th and 21st centuries. An appropriate orientation of a building can provide thermally comfortable indoor temperatures which otherwise can consume extra energy to condition these spaces through all the seasons. This experimental study investigates the potential effect of this solar passive design strategy on indoor temperatures and a simple model is presented for predicting indoor temperatures based upon the ambient temperatures.

  2. Greenhouse Gas Data Publication Tool

    Data.gov (United States)

    U.S. Environmental Protection Agency — This tool to gives you access to greenhouse gas data reported to EPA by large facilities and suppliers in the United States through EPA's Greenhouse Gas Reporting...

  3. Greenhouse production systems for people

    NARCIS (Netherlands)

    Giacomelli, G.A.; Sase, S.; Cramer, R.; Hoogeboom, J.; McKenzie, A.; Parbst, K.; Sacrascia-Mugnozza, G.; Selina, P.; Sharp, D.A.; Voogt, J.O.; Weel, van P.A.; Mears, D.

    2012-01-01

    Environmentally sound greenhouse production requires that: demand for market products is understood; greenhouse design addresses the climate circum-stances; input resources are available and consumed efficiently, and; there must be a reasonable balance of production products to the environmental

  4. Precipitation rates and atmospheric heat transport during the Cenomanian greenhouse warming in North America: Estimates from a stable isotope mass-balance model

    Science.gov (United States)

    Ufnar, David F.; Ludvigson, Greg A.; Gonzalez, L.; Grocke, D.R.

    2008-01-01

    Stable isotope mass-balance modeling results of meteoric ??18O values from the Cenomanian Stage of the Cretaceous Western Interior Basin (KWIB) suggest that precipitation and evaporation fluxes were greater than that of the present and significantly different from simulations of Albian KWIB paleohydrology. Sphaerosiderite meteoric ??18O values have been compiled from the Lower Tuscaloosa Formation of southwestern Mississippi (25??N paleolatitude), The Dakota Formation Rose Creek Pit, Fairbury Nebraska (35??N) and the Dunvegan Formation of eastern British Columbia (55??N paleolatitude). These paleosol siderite ??18O values define a paleolatitudinal gradient ranging from - 4.2??? VPDB at 25??N to - 12.5??? VPDB at 55??N. This trend is significantly steeper and more depleted than a modern theoretical siderite gradient (25??N: - 1.7???; 65??N: - 5.6??? VPDB ), and a Holocene meteoric calcite trend (27??N: - 3.6???; 67??N: - 7.4??? VPDB). The Cenomanian gradient is also comparatively steeper than the Albian trend determined for the KWIB in the mid- to high latitudes. The steep latitudinal trend in meteoric ??18O values may be the result of increased precipitation and evaporation fluxes (amount effects) under a more vigorous greenhouse-world hydrologic cycle. A stable-isotope mass-balance model has been used to generate estimates of precipitation and evaporation fluxes and precipitation rates. Estimates of Cenomanian precipitation rates based upon the mass-balance modeling of the KWIB range from 1400??mm/yr at 25??N paleolatitude to 3600??mm/yr at 45??N paleolatitude. The precipitation-evaporation (P-E) flux values were used to delineate zones of moisture surplus and moisture deficit. Comparisons between Cenomanian P-E and modern theoretical siderite, and Holocene calcite latitudinal trends shows an amplification of low-latitude moisture deficits between 5-25??N paleolatitude and moisture surpluses between 40-60??N paleolatitude. The low-latitude moisture deficits

  5. A THERMODYNAMIC CAVITATION MODEL APPLICABLE TO HIGH TEMPERATURE FLOW

    Directory of Open Access Journals (Sweden)

    De-Min Liu

    2011-01-01

    Full Text Available Cavitation is not only related with pressure, but also affected by temperature. Under high temperature, temperature depression of liquids is caused by latent heat of vaporization. The cavitation characteristics under such condition are different from those under room temperature. The paper focuses on thermodynamic cavitation based on the Rayleigh-Plesset equation and modifies the mass transfer equation with fully consideration of the thermodynamic effects and physical properties. To validate the modified model, the external and internal flow fields, such as hydrofoil NACA0015 and nozzle, are calculated, respectively. The hydrofoil NACA0015's cavitation characteristic is calculated by the modified model at different temperatures. The pressure coefficient is found in accordance with the experimental data. The nozzle cavitation under the thermodynamic condition is calculated and compared with the experiment.

  6. Finite Temperature Casimir Effect in Randall-Sundrum Models

    CERN Document Server

    Rypestøl, Marianne

    2009-01-01

    The finite temperature Casimir effect for a scalar field in the bulk region of the two Randall-Sundrum models, RSI and RSII, is studied. We calculate the Casimir energy and the Casimir force for two parallel plates with separation $a$ on the visible brane in the RSI model. High-temperature and low-temperature cases are covered. Attractiveness versus repulsiveness of the temperature correction to the force is discussed in the typical special cases of Dirichlet-Dirichlet, Neumann-Neumann, and Dirichlet-Neumann boundary conditions at low temperature. The Abel-Plana summation formula is made use of, as this turns out to be most convenient. Some comments are made on the related contemporary literature.

  7. Modelling of the plasma-MIG welding temperature field

    Institute of Scientific and Technical Information of China (English)

    Bai Yan; Gao Hongming; Wu Lin; Shi Lei

    2006-01-01

    A three-dimensional simulation model for the plasma-MIG welding process, which takes the interaction between the plasma arc and MIG arc into account, is presented and the quasi-steady temperature fields on the workpiece are calculated with the model. The 10 mm-5A06 aluminum alloy is welded and the temperature fields are measured with the thermoelectric couple. The simulation results and measured results show that the biggest deviation of peak temperature between them is below 20 ℃ , which indicates good coincidence between the simulation and measurement.

  8. Predicting the energy consumption of heated plastic greenhouses in south-eastern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, J. C.; Baile, A.; Bonachela, S.; Gonzalez-Real, M. M.; Perez-Parra, J.

    2006-07-01

    Measurements of heat consumption in a parral type greenhouse, equipped with an air-heating system, were carried out in south-eastern Spain (Almeria) during the 1998/99 winter. From the daily values of heat consumption (Qd, MJ m-2 d-1) recorded in five identical greenhouses heated to different night temperature set-points (Tc), and data of minimum outside air temperature (Te,min), relationships between Qd and the temperature difference (Tmin = Tc . Te,min) were established. Linear regressions between Qd and delta Tmin gave satisfactory fits (R2 ranging from 0.75 to 0.83), considering that Te,min was the only input data for the model. When all data were pooled, the correlation was curvilinear, the best fit to a 2nd order polynomial being Qd = 0.049 deltaTmin 2 . 0.001 Tmin + 1.107 (R2 = 0.89). Validation of this model was performed using data obtained during other years, giving a fair agreement at the daily (R2 0.86), 10-day (R2 = 0.95) and yearly (R2 = 0.99) time scales. This simple model could be of interest to growers for decision-making related to the choice of set-point temperature and crop planning in heated greenhouses. (Author)

  9. Mitigation of greenhouse gases from agriculture

    DEFF Research Database (Denmark)

    Schils, R.L.M.; Ellis, J. L.; de Klein, C. A. M.

    2013-01-01

    Models are widely used to simulate the emission of greenhouse gases (GHG). They help to identify knowledge gaps, estimate total emissions for inventories, develop mitigation options and policies, raise awareness and encourage adoption. These models vary in scale, scope and methodological approach...

  10. On the role of atmosphere-ocean interactions in the expected long-term changes of the Earth's ozone layer caused by greenhouse gases

    Science.gov (United States)

    Zadorozhny, Alexander; Dyominov, Igor

    It is well known that anthropogenic emissions of greenhouse gases into the atmosphere produce a global warming of the troposphere and a global cooling of the stratosphere. The expected stratospheric cooling essentially influences the ozone layer via increased polar stratospheric cloud formation and via temperature dependences of the gas phase reaction rates. One more mechanism of how greenhouse gases influences the ozone layer is enhanced water evaporation from the oceans into the atmosphere because of increasing temperatures of the ocean surface due to greenhouse effect. The subject of this paper is a study of the influence of anthropogenic pollution of the atmosphere by the greenhouse gases CO2, CH4, N2O and ozone-depleting chlorine and bromine compounds on the expected long-term changes of the ozone layer with taking into account an increase of water vapour content in the atmosphere due to greenhouse effect. The study based on 2-D zonally averaged interactive dynamical radiative-photochemical model of the troposphere and stratosphere. The model allows to self-consistently calculating diabatic circulation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the South to North Poles, as well as distribution of sulphate aerosol particles and polar stratospheric clouds of two types. It was supposed in the model that an increase of the ocean surface temperature caused by greenhouse effect is similar to calculated increase of atmospheric surface temperature. Evaporation rate from the ocean surface was computed in dependence of latitude. The model time-dependent runs were made for the period from 1975 to 2100 using two IPCC scenarios depicting maximum and average expected increases of greenhouse gases in the atmosphere. The model calculations show that anthropogenic increasing of water vapour abundance in the atmosphere due to heating of the ocean surface caused by greenhouse effect gives a sensible contribution to the expected ozone

  11. Relative roles of anthropogenic aerosols and greenhouse gases in land and oceanic monsoon changes during past 156 years in CMIP5 models

    Science.gov (United States)

    Zhang, Lei; Li, Tim

    2016-05-01

    Relative roles of anthropogenic aerosols (AAs) and greenhouse gases (GHGs) in land and oceanic monsoon changes during boreal summer over the period 1850-2005 in Coupled Model Intercomparison Project Phase 5 (CMIP5) models are explored. It is found that the GHG effect dominates rainfall trend over oceanic monsoon region. As a result, precipitation over western North Pacific (WNP) monsoon region and Intertropical Convergence Zone (ITCZ) over tropical eastern Pacific are strengthened through the so-called "richest-get-richer" mechanism. Over land monsoon region, GHG and AA effects are different over India and East Asia (EA). The two effects tend to offset each other over India, but the AA effect dominates over EA and induces a drying trend. The weakened effect of GHGs on EA is attributed to the large offset of thermodynamic and dynamic effects associated with GHGs. While the former tends to strengthen EA rainfall through increased moisture, the latter tends to decrease EA rainfall due to the strengthened WNP monsoon impact.

  12. The impact of plug-in vehicles on greenhouse gas and criteria pollutants emissions in an urban air shed using a spatially and temporally resolved dispatch model

    Science.gov (United States)

    Razeghi, Ghazal; Brown, Tim; Samuelsen, G. Scott

    With the introduction of plug-in vehicles (PEVs) into the light-duty vehicle fleet, the tail-pipe emissions of GHGs and criteria pollutants will be partly transferred to electricity generating units. To study the impact of PEVs on well-to-wheels emissions, the U.S. Western electrical grid serving the South Coast Air Basin (SoCAB) of California is modeled with both spatial and temporal resolution at the level of individual power plants. Electricity load is calculated and projected for future years, and the temporal electricity generation of each power plant within the SoCAB is modeled based on historical data and knowledge of electricity generation and dispatch. Due to the efficiency and pollutant controls governing the performance of the Western grid, the deployment of PEVs results in a daily reduction of greenhouse gases (GHGs) and tail-pipe emissions, especially in the critical morning and afternoon commute hours. The extent of improvement depends on charging scenarios, future grid mix, and the number and type of plug-in vehicles. In addition, charging PEVs using wind energy that would otherwise be curtailed can result in a substantial emissions reduction. Smart control will be required to manage PEV charging in order to mitigate renewable intermittencies and decrease emissions associated with peaking power production.

  13. Large-eddy simulation, atmospheric measurement and inverse modeling of greenhouse gas emissions at local spatial scales

    Science.gov (United States)

    Nottrott, Anders Andelman

    non-volatile switching of magnetization would be more promising for information storage or MERAM devices with lower energy consumption and the magnetic state can be further controlled by voltage impulse. In this work, we first study the equivalent of direct and converse magnetoelectric effects. The resonant direct and converse magnetoelectric (ME) effects have been investigated experimentally and theoretically in FeGa/PZT/FeGa sandwich laminate composites. The frequency responses of direct and converse magnetoelectric effects were measured under the same electric and magnetic bias conditions. The resonant direct ME effect (DME) occurs at an antiresonance frequency, while resonant converse ME effect (CME) occurs at a resonance frequency. The antiresonance and resonance frequencies have close but different values under identical bias conditions. The magnitudes of resonant effective ME coefficients for direct and converse ME effects are also not equal. Based on different sets of constitutive equations of the materials for DME and CME, a new model was developed to describe the frequency response of DME and CME in laminate composite, which was in good agreement with the experimental results. Inequivalence of resonant ME effects is ascribed to the different mechanical and electrical boundary conditions for DME and CME. On the other hand, similar bias E and H field dependence was observed for both DME and CME resonance frequencies and resonant coefficients, indicating consistency between DME and CME effects. In the study of the frequency response of DME and CME, the linear piezoelectric effect is used. However, this linear piezoelectric effect in converse magnetoelectric coupling would lead to "butter-fly" like magnetization vs. electric field curve which leads to a "volatile" behavior in magnetic memory system. In the presented study, a unique ferroelastic switching pathway in ferroelectric substrates is utilized to produce two distinct, reversible and stable lattice strain

  14. A Sustained Greenhouse Climate on Mars following an Impact Event

    Science.gov (United States)

    Segura, T.; Toon, B.; Colaprete, T.; McKay, C.

    2007-12-01

    The existence of craters of size 200 km and greater proves that large (30-250 km diameter) impacts were abundant in the early history of Mars. Injected water from three sources (the impactor, water innate to the crater, and from melting of the polar caps) provide periods of rain following such impacts. Very hot, global debris blankets are another consequence of these large impacts, and these layers create a thermal pulse that propagates into the subsurface, melting additional water. The melted and precipitated water and debris blanket combine to produce a temporarily altered climate. This research shows time-dependent modeled calculations of this altered climate, and focuses in particular on a possible "runaway" greenhouse state that might be initiated as a result of the additional heat and a sufficiently rapid supply of the melted and precipitated water to the atmosphere. Our model is a 1-D radiative-convective model coupled to a 1-D model of the regolith to calculate the evolution of the surface and subsurface temperatures. The effects of latent heating, cloud condensation, precipitation, and evaporation are included in the model. We also show mathematically how the effects of large asteroid or comet impacts can cause a planet to reach the runaway greenhouse state, and illustrate how this solution is part of a bi-stable climate solution for terrestrial planets. One solution is found when a planet cools from high temperature, the other when the planet warms from a cool state. The hot solution represents a planet in the runaway regime, while the cold solution represents a planet with most of its water condensed at the surface. If a planet cools from a large temperature perturbation, caused by a large impact, it is possible that the planet will remain stable in the runaway climate rather than returning to the low temperature climate state.

  15. Constitutive modelling of aluminium alloy sheet at warm forming temperatures

    Science.gov (United States)

    Kurukuri, S.; Worswick, M. J.; Winkler, S.

    2016-08-01

    The formability of aluminium alloy sheet can be greatly improved by warm forming. However predicting constitutive behaviour under warm forming conditions is a challenge for aluminium alloys due to strong, coupled temperature- and rate-sensitivity. In this work, uniaxial tensile characterization of 0.5 mm thick fully annealed aluminium alloy brazing sheet, widely used in the fabrication of automotive heat exchanger components, is performed at various temperatures (25 to 250 °C) and strain rates (0.002 and 0.02 s-1). In order to capture the observed rate- and temperature-dependent work hardening behaviour, a phenomenological extended-Nadai model and the physically based (i) Bergstrom and (ii) Nes models are considered and compared. It is demonstrated that the Nes model is able to accurately describe the flow stress of AA3003 sheet at different temperatures, strain rates and instantaneous strain rate jumps.

  16. Produtividade do tomateiro em diferentes substratos e modelos de casas de vegetação Tomato crop production under different substrates and greenhouse models

    Directory of Open Access Journals (Sweden)

    Osmar A. Carrijo

    2004-03-01

    Full Text Available Um experimento com a cultura do tomate, foi instalado na Embrapa Hortaliças em Brasília, durante os anos de 2000 e 2001, para avaliar a produção do tomateiro em diferentes substratos e casas de vegetação. Os substratos utilizados foram casca de arroz, casca de arroz parcialmente carbonizada, fibra de coco verde, lã de rocha, maravalha, serragem e substrato para produção de mudas utilizado na Embrapa Hortaliças (150 L de terra de subsolo, 50 L de casca de arroz parcialmente carbonizada e 17 L de esterco de galinha. Os modelos de casas de vegetação utilizados foram teto em arco, arco com teto convectivo e capela. Não foi verificada diferença estatística significativa quanto a produção de frutos comerciais entre os substratos fibra de coco (10,4 kg m-2, serragem (9,3 kg m-2, casca de arroz carbonizada (9,3 kg m-2 e maravalha (9,0 kg m-2. A menor produção foi obtida com o substrato lã de rocha (6,4 kg m-2. Houve redução da produção entre os anos de cultivo, em torno de 33%, em decorrência de um intenso ataque de traça do tomateiro (Tuta absoluta em todas as casas de vegetação, prejudicando a produtividade. O maior peso médio dos frutos foi obtido sobre a fibra de coco (128 g m-2 e casca de arroz carbonizada (123 g m-2, independente do modelo de casa de vegetação utilizado.The trial was carried out at Embrapa Hortaliças, in Brasilia, Brazil, to evaluate the performance of tomato crop production during two years (2000 and 2001, under three greenhouse models and different types of substrates. The greenhouse models were arch roof; even span and an arch roof with upper convective aperture. The substrates were rice husk, carbonized rice husk, coconut fiber, sawdust, coarsed sawdust, rockwool and a substrate for seedling production used at Embrapa Hortaliças. No significant statistical difference was verified for tomatoes cultivated in coconut fiber (10,4 kg m-2, sawdust (9,9 kg m-2, carbonized rice husk (9,3 kg m-2 and

  17. A Temperature-Dependent Battery Model for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Leonardo M. Rodrigues

    2017-02-01

    Full Text Available Energy consumption is a major issue in Wireless Sensor Networks (WSNs, as nodes are powered by chemical batteries with an upper bounded lifetime. Estimating the lifetime of batteries is a difficult task, as it depends on several factors, such as operating temperatures and discharge rates. Analytical battery models can be used for estimating both the battery lifetime and the voltage behavior over time. Still, available models usually do not consider the impact of operating temperatures on the battery behavior. The target of this work is to extend the widely-used Kinetic Battery Model (KiBaM to include the effect of temperature on the battery behavior. The proposed Temperature-Dependent KiBaM (T-KiBaM is able to handle operating temperatures, providing better estimates for the battery lifetime and voltage behavior. The performed experimental validation shows that T-KiBaM achieves an average accuracy error smaller than 0.33%, when estimating the lifetime of Ni-MH batteries for different temperature conditions. In addition, T-KiBaM significantly improves the original KiBaM voltage model. The proposed model can be easily adapted to handle other battery technologies, enabling the consideration of different WSN deployments.

  18. A Temperature-Dependent Battery Model for Wireless Sensor Networks.

    Science.gov (United States)

    Rodrigues, Leonardo M; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco

    2017-02-22

    Energy consumption is a major issue in Wireless Sensor Networks (WSNs), as nodes are powered by chemical batteries with an upper bounded lifetime. Estimating the lifetime of batteries is a difficult task, as it depends on several factors, such as operating temperatures and discharge rates. Analytical battery models can be used for estimating both the battery lifetime and the voltage behavior over time. Still, available models usually do not consider the impact of operating temperatures on the battery behavior. The target of this work is to extend the widely-used Kinetic Battery Model (KiBaM) to include the effect of temperature on the battery behavior. The proposed Temperature-Dependent KiBaM (T-KiBaM) is able to handle operating temperatures, providing better estimates for the battery lifetime and voltage behavior. The performed experimental validation shows that T-KiBaM achieves an average accuracy error smaller than 0.33%, when estimating the lifetime of Ni-MH batteries for different temperature conditions. In addition, T-KiBaM significantly improves the original KiBaM voltage model. The proposed model can be easily adapted to handle other battery technologies, enabling the consideration of different WSN deployments.

  19. A Temperature-Dependent Battery Model for Wireless Sensor Networks

    Science.gov (United States)

    Rodrigues, Leonardo M.; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco

    2017-01-01

    Energy consumption is a major issue in Wireless Sensor Networks (WSNs), as nodes are powered by chemical batteries with an upper bounded lifetime. Estimating the lifetime of batteries is a difficult task, as it depends on several factors, such as operating temperatures and discharge rates. Analytical battery models can be used for estimating both the battery lifetime and the voltage behavior over time. Still, available models usually do not consider the impact of operating temperatures on the battery behavior. The target of this work is to extend the widely-used Kinetic Battery Model (KiBaM) to include the effect of temperature on the battery behavior. The proposed Temperature-Dependent KiBaM (T-KiBaM) is able to handle operating temperatures, providing better estimates for the battery lifetime and voltage behavior. The performed experimental validation shows that T-KiBaM achieves an average accuracy error smaller than 0.33%, when estimating the lifetime of Ni-MH batteries for different temperature conditions. In addition, T-KiBaM significantly improves the original KiBaM voltage model. The proposed model can be easily adapted to handle other battery technologies, enabling the consideration of different WSN deployments. PMID:28241444

  20. Influence of greenhouse climate and plant density on external quality of chrysanthemum (Dendranthema grandiflorum (Ramat.)Kitamura) : First steps towards a quality model

    NARCIS (Netherlands)

    Carvalho, S.M.P.; Heuvelink, E.

    2001-01-01

    The effects of greenhouse climate and plant density on external quality of chrysanthemum (Dendranthema grandiflorum syn. Chrysanthemum morifolium) are reviewed. The external quality aspects analysed in this paper are stem morphology (length, diameter and "strength"), leaf morphology (number and

  1. Identificación de un modelo del clima en un invernadero mediante métodos por subespacios Identifying a greenhouse climate model by using subspace methods

    Directory of Open Access Journals (Sweden)

    Ruiz Palacios Fredy Orlando

    2010-08-01

    Full Text Available En este trabajo se presenta el desarrollo de un modelo dinámico del clima en un invernadero ubicado en la Sabana de Bogotá. Se realiza la estimación de un modelo tipo caja negra obtenido a partir de datos experimentales. Se propone una estructura a partir de principios físicos que divide el sistema en dos volúmenes de control dados por el aire libre dentro del invernadero y el aire atrapado por el follaje. El modelo es seleccionado, dentro de una familia de sistemas línea- les descritos en variables de estado, a través de métodos de identificación por subespacios. El modelo obtenido es capaz de explicar el comportamiento del clima en el aire y en el follaje con errores inferiores al 8%. Este desempeño es comparable al de otros estudios reportados en la literatura, con la ventaja de que el modelo empleado es lineal.This paper presents the development of a climate dynamics model for a greenhouse located on the Bogota plateau. A black-box model was estimated from experimental data, considering a novel system structure derived from a first principles model and experimental tests. It considered two control volumes, one given by the air over the crop and a second one formed by the air trapped by crop foliage. The model was selected from a set of linear, discrete-time, state-variable systems using subspace identification methods. The estimated system was able to predict climate dynamics for both control volumes, having errors below 8%. Such performance was comparable to previous work reported in literature while the obtained model was a low-complexity linear system.

  2. Comparison of Greenhouse Gas Emissions between Two Dairy Farm Systems (Conventional vs. Organic Management) in New Hampshire Using the Manure DNDC Biogeochemical Model

    Science.gov (United States)

    Dorich, C.; Contosta, A.; Li, C.; Brito, A.; Varner, R. K.

    2013-12-01

    Agriculture contributes 20 to 25 % of the total anthropogenic greenhouse gas (GHG) emissions globally. These agricultural emissions are primarily in the form of methane (CH4) and nitrous oxide (N2O) with these GHG accounting for roughly 40 and 80 % of the total anthropogenic emissions of CH4 and N2O, respectively. Due to varied management and the complexities of agricultural ecosystems, it is difficult to estimate these CH4 and N2O emissions. The IPCC emission factors can be used to yield rough estimates of CH4 and N2O emissions but they are often based on limited data. Accurate modeling validated by measurements is needed in order to identify potential mitigation areas, reduce GHG emissions from agriculture, and improve sustainability of farming practices. The biogeochemical model Manure DNDC was validated using measurements from two dairy farms in New Hampshire, USA in order to quantify GHG emissions under different management systems. One organic and one conventional dairy farm operated by the University of New Hampshire's Agriculture Experiment Station were utilized as the study sites for validation of Manure DNDC. Compilation of management records started in 2011 to provide model inputs. Model results were then compared to field collected samples of soil carbon and nitrogen, above-ground biomass, and GHG fluxes. Fluxes were measured in crop, animal, housing, and waste management sites on the farms in order to examine the entire farm ecosystem and test the validity of the model. Fluxes were measured by static flux chambers, with enteric fermentation measurements being conducted by the SF6 tracer test as well as a new method called Greenfeeder. Our preliminary GHG flux analysis suggests higher emissions than predicted by IPCC emission factors and equations. Results suggest that emissions from manure management is a key concern at the conventional dairy farm while bedded housing at the organic dairy produced large quantities of GHG.

  3. Event-based stormwater management pond runoff temperature model

    Science.gov (United States)

    Sabouri, F.; Gharabaghi, B.; Sattar, A. M. A.; Thompson, A. M.

    2016-09-01

    Stormwater management wet ponds are generally very shallow and hence can significantly increase (about 5.4 °C on average in this study) runoff temperatures in summer months, which adversely affects receiving urban stream ecosystems. This study uses gene expression programming (GEP) and artificial neural networks (ANN) modeling techniques to advance our knowledge of the key factors governing thermal enrichment effects of stormwater ponds. The models developed in this study build upon and compliment the ANN model developed by Sabouri et al. (2013) that predicts the catchment event mean runoff temperature entering the pond as a function of event climatic and catchment characteristic parameters. The key factors that control pond outlet runoff temperature, include: (1) Upland Catchment Parameters (catchment drainage area and event mean runoff temperature inflow to the pond); (2) Climatic Parameters (rainfall depth, event mean air temperature, and pond initial water temperature); and (3) Pond Design Parameters (pond length-to-width ratio, pond surface area, pond average depth, and pond outlet depth). We used monitoring data for three summers from 2009 to 2011 in four stormwater management ponds, located in the cities of Guelph and Kitchener, Ontario, Canada to develop the models. The prediction uncertainties of the developed ANN and GEP models for the case study sites are around 0.4% and 1.7% of the median value. Sensitivity analysis of the trained models indicates that the thermal enrichment of the pond outlet runoff is inversely proportional to pond length-to-width ratio, pond outlet depth, and directly proportional to event runoff volume, event mean pond inflow runoff temperature, and pond initial water temperature.

  4. Performance of underground heat storage system in a double-film-covered greenhouse

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    An underground heat storage system in a double-film-covered greenhouse and an adjacent greenhouse without the heat storage system were designed on the basis of plant physiology to reduce the energy consumption in greenhouses. The results indicated that the floor temperature was respectively 5.2 ℃, 4.6 ℃ and 2.0℃ higher than that of the soil in the adjacent reference greenhouse after heat storage in a clear, cloudy and overcast sky in winter. Results showed that the temperature and humidity were feasible for plant growth in the heat saving greenhouse.

  5. Study on Forewarning Model Construction Technology of Chilling Injury for Cucumber in Greenhouse%日光温室黄瓜低温冷害预警模型构建技术研究

    Institute of Scientific and Technical Information of China (English)

    李楠; 薛晓萍; 张继波; 李鸿怡

    2015-01-01

    利用数学统计方法对历史气象资料进行统计分析,并根据日光温室黄瓜低温冷害发生的气象因子等级指标,计算得到温室内最低气温、温室内地表温度、太阳总辐射、日照时数4个气象要素的等级指标;统计分析2007年至2012年淄博、莱芜日光温室小气候自动监测站和自动气象观测站的资料,利用结构方程模型确定低温预警模型中的因子,根据层次分析法构建判断矩阵,利用 DPS 分析因子权重系数,最终建立了日光温室黄瓜低温冷害预警模型。利用临淄、莱芜、利津、平度、章丘五站2012年11月1日至2013年5月31日的气象观测资料对该模型进行检验,结果表明预警等级与实际等级完全一致的准确率为63%~77%,相差在1个等级以内的准确率在97%~99%。%The statistical analysis on the historical meteorological date was conducted by mathematical statistical methods,and four grade index of meteorological factors of the lowest temperature,ground surface temperature,total solar irradiation and sunshine hours in greenhouse were calculated according the cucumber chilling injury grade index of temperature in facility.Analyzing the micro -climate data and meteorology data in Zibo and Laiwu of 2007 to 2012,using the structural equation modeling(SEM)to choose factors of forewar-ning model,constructing judgment matrix by analytic hierarchy process (AHP)and analyzing the factors weight coefficient by DPS,the chilling injury forewarning model of greenhouse was built finally.Using the data of Linzi,Laiwu,Lijin,Pingdu and Zhangqiu from November 1,2012 to May 31,2013 to verify the model,the result showed that the rate of forewarning grades and chilling injury happened grades were 63% ~77% in full agreement,and the rate of grades difference in 1 grade was 97% ~99%.

  6. Greenhouse gas network design using backward Lagrangian particle dispersion modelling, Part 1: Methodology and Australian test case

    CSIR Research Space (South Africa)

    Ziehn, T

    2014-09-01

    Full Text Available inverse modelling framework to calculate the relationship between weekly surface fluxes, comprising contributions from the biosphere and fossil fuel combustion, and hourly concentration observations for the Australian continent. Meteorological driving...

  7. Modeling greenhouse gas emissions (CO2, N2O, CH4) from managed arable soils with a fully coupled hydrology-biogeochemical modeling system simulating water and nutrient transport and associated carbon and nitrogen cycling at catchment scale

    Science.gov (United States)

    Klatt, Steffen; Haas, Edwin; Kraus, David; Kiese, Ralf; Butterbach-Bahl, Klaus; Kraft, Philipp; Plesca, Ina; Breuer, Lutz; Zhu, Bo; Zhou, Minghua; Zhang, Wei; Zheng, Xunhua; Wlotzka, Martin; Heuveline, Vincent

    2014-05-01

    The use of mineral nitrogen fertilizer sustains the global food production and therefore the livelihood of human kind. The rise in world population will put pressure on the global agricultural system to increase its productivity leading most likely to an intensification of mineral nitrogen fertilizer use. The fate of excess nitrogen and its distribution within landscapes is manifold. Process knowledge on the site scale has rapidly grown in recent years and models have been developed to simulate carbon and nitrogen cycling in managed ecosystems on the site scale. Despite first regional studies, the carbon and nitrogen cycling on the landscape or catchment scale is not fully understood. In this study we present a newly developed modelling approach by coupling the fully distributed hydrology model CMF (catchment modelling framework) to the process based regional ecosystem model LandscapeDNDC for the investigation of hydrological processes and carbon and nitrogen transport and cycling, with a focus on nutrient displacement and resulting greenhouse gas emissions in a small catchment at the Yanting Agro-ecological Experimental Station of Purple Soil, Sichuan province, China. The catchment hosts cypress forests on the outer regions, arable fields on the sloping croplands cultivated with wheat-maize rotations and paddy rice fields in the lowland. The catchment consists of 300 polygons vertically stratified into 10 soil layers. Ecosystem states (soil water content and nutrients) and fluxes (evapotranspiration) are exchanged between the models at high temporal scales (hourly to daily) forming a 3-dimensional model application. The water flux and nutrients transport in the soil is modelled using a 3D Richards/Darcy approach for subsurface fluxes with a kinematic wave approach for surface water runoff and the evapotranspiration is based on Penman-Monteith. Biogeochemical processes are modelled by LandscapeDNDC, including soil microclimate, plant growth and biomass allocation

  8. Temperature dependence of heterogeneous nucleation: Extension of the Fletcher model

    Science.gov (United States)

    McGraw, Robert; Winkler, Paul; Wagner, Paul

    2015-04-01

    Recently there have been several cases reported where the critical saturation ratio for onset of heterogeneous nucleation increases with nucleation temperature (positive slope dependence). This behavior contrasts with the behavior observed in homogeneous nucleation, where a decreasing critical saturation ratio with increasing nucleation temperature (negative slope dependence) seems universal. For this reason the positive slope dependence is referred to as anomalous. Negative slope dependence is found in heterogeneous nucleation as well, but because so few temperature-dependent measurements have been reported, it is not presently clear which slope condition (positive or negative) will become more frequent. Especially interesting is the case of water vapor condensation on silver nanoparticles [Kupc et al., AS&T 47: i-iv, 2013] where the critical saturation ratio for heterogeneous nucleation onset passes through a maximum, at about 278K, with higher (lower) temperatures showing the usual (anomalous) temperature dependence. In the present study we develop an extension of Fletcher's classical, capillarity-based, model of heterogeneous nucleation that explicitly resolves the roles of surface energy and surface entropy in determining temperature dependence. Application of the second nucleation theorem, which relates temperature dependence of nucleation rate to cluster energy, yields both necessary and sufficient conditions for anomalous temperature behavior in the extended Fletcher model. In particular it is found that an increasing contact angle with temperature is a necessary, but not sufficient, condition for anomalous temperature dependence to occur. Methods for inferring microscopic contact angle and its temperature dependence from heterogeneous nucleation probability measurements are discussed in light of the new theory.

  9. Apparent limitations in the ability of CMIP5 climate models to simulate recent multi-decadal change in surface temperature: implications for global temperature projections

    Science.gov (United States)

    Power, Scott; Delage, François; Wang, Guomin; Smith, Ian; Kociuba, Greg

    2016-09-01

    Observed surface temperature trends over the period 1998-2012/2014 have attracted a great deal of interest because of an apparent slowdown in the rate of global warming, and contrasts between climate model simulations and observations of such trends. Many studies have addressed the statistical significance of these relatively short-trends, whether they indicate a possible bias in the model values and the implications for global warming generally. Here we re-examine these issues, but as they relate to changes over much longer-term changes. We find that on multi-decadal time scales there is little evidence for any change in the observed global warming rate, but some evidence for a recent temporary slowdown in the warming rate in the Pacific. This multi-decadal slowdown can be partly explained by a cool phase of the Interdecadal Pacific Oscillation and a short-term excess of La Niña events. We also analyse historical and projected changes in 38 CMIP climate models. All of the model simulations examined simulate multi-decadal warming in the Pacific over the past half-century that exceeds observed values. This difference cannot be fully explained by observed internal multi-decadal climate variability, even if allowance is made for an apparent tendency for models to underestimate internal multi-decadal variability in the Pacific. Models which simulate the greatest global warming over the past half-century also project warming that is among the highest of all models by the end of the twenty-first century, under both low and high greenhouse gas emission scenarios. Given that the same models are poorest in representing observed multi-decadal temperature change, confidence in the highest projections is reduced.

  10. Apparent limitations in the ability of CMIP5 climate models to simulate recent multi-decadal change in surface temperature: implications for global temperature projections

    Science.gov (United States)

    Power, Scott; Delage, François; Wang, Guomin; Smith, Ian; Kociuba, Greg

    2017-07-01

    Observed surface temperature trends over the period 1998-2012/2014 have attracted a great deal of interest because of an apparent slowdown in the rate of global warming, and contrasts between climate model simulations and observations of such trends. Many studies have addressed the statistical significance of these relatively short-trends, whether they indicate a possible bias in the model values and the implications for global warming generally. Here we re-examine these issues, but as they relate to changes over much longer-term changes. We find that on multi- decadal time scales there is little evidence for any change in the observed global warming rate, but some evidence for a recent temporary slowdown in the warming rate in the Pacific. This multi-decadal slowdown can be partly explained by a cool phase of the Interdecadal Pacific Oscillation and a short-term excess of La Niña events. We also analyse historical and projected changes in 38 CMIP climate models. All of the model simulations examined simulate multi-decadal warming in the Pacific over the past half-century that exceeds observed values. This difference cannot be fully explained by observed internal multi-decadal climate variability, even if allowance is made for an apparent tendency for models to underestimate internal multi-decadal variability in the Pacific. Models which simulate the greatest global warming over the past half-century also project warming that is among the highest of all models by the end of the twenty-first century, under both low and high greenhouse gas emission scenarios. Given that the same models are poorest in representing observed multi-decadal temperature change, confidence in the highest projections is reduced.

  11. Analytic regularization of the Yukawa model at finite temperature

    CERN Document Server

    Malbouisson, A P C; Svaiter, N F

    1996-01-01

    We analyse the one-loop fermionic contribution for the scalar effective potential in the temperature dependent Yukawa model. In order to regularize the model a mix between dimensional and analytic regularization procedures is used. We find a general expression for the fermionic contribution in arbitrary spacetime dimension. It is found that in D=3 this contribution is finite.

  12. LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes

    Science.gov (United States)

    Stepanenko, Victor; Mammarella, Ivan; Ojala, Anne; Miettinen, Heli; Lykosov, Vasily; Vesala, Timo

    2016-05-01

    A one-dimensional (1-D) model for an enclosed basin (lake) is presented, which reproduces temperature, horizontal velocities, oxygen, carbon dioxide and methane in the basin. All prognostic variables are treated in a unified manner via a generic 1-D transport equation for horizontally averaged property. A water body interacts with underlying sediments. These sediments are represented by a set of vertical columns with heat, moisture and CH4 transport inside. The model is validated vs. a comprehensive observational data set gathered at Kuivajärvi Lake (southern Finland), demonstrating a fair agreement. The value of a key calibration constant, regulating the magnitude of methane production in sediments, corresponded well to that obtained from another two lakes. We demonstrated via surface seiche parameterization that the near-bottom turbulence induced by surface seiches is likely to significantly affect CH4 accumulation there. Furthermore, our results suggest that a gas transfer through thermocline under intense internal seiche motions is a bottleneck in quantifying greenhouse gas dynamics in dimictic lakes, which calls for further research.

  13. Temperature Drift Modeling of FOG Based on LS-WSVM

    Institute of Scientific and Technical Information of China (English)

    WANG Li-ping; KONG Xiao-mei; FU Meng-yin; WANG Mei-ling; ZHANG Jia-wen; JIANG Ming

    2008-01-01

    Large temperature drift is an important factor for improving the performance of FOG. A trend term of temperature drift of FOG is obtained using stationary wavelets transform, and an FOG drift algorithm with least squares wavelet support vector machine (LS-WSVM) is developed. The algorithm used Maxihat wavelet as a kernel function of LSWSVM to establish an FOG drift model. It has better modeling precise than LS-WSVM model with Gauss kernel. Results indicate the efficiency of this algorithm of LS-WSVM.

  14. Mathematical modelling of steam generator and design of temperature regulator

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanovic, S.S. [EE Institute Nikola Tesla, Belgrade (Yugoslavia)

    1999-07-01

    The paper considers mathematical modelling of once-through power station boiler and numerical algorithm for simulation of the model. Fast and numerically stable algorithm based on the linearisation of model equations and on the simultaneous solving of differential and algebraic equations is proposed. The paper also presents the design of steam temperature regulator by using the method of projective controls. Dynamic behaviour of the system closed with optimal linear quadratic regulator is taken as the reference system. The desired proprieties of the reference system are retained and solutions for superheated steam temperature regulator are determined. (author)

  15. MGP : a tool for wide range temperature modelling

    Energy Technology Data Exchange (ETDEWEB)

    Morales, A.F. [Inst. Tecnologico Autonomo de Mexico, Mexico City (Mexico); Seisdedos, L.V. [Univ. de Oriente, Santiago de Cuba (Cuba). Dept. de Control Automatico

    2006-07-01

    This paper proposed a practical temperature modelling tool that used genetic multivariate polynomials to determine polynomial expressions of enthalpy and empirical heat transfer equations in superheaters. The model was designed to transform static parameter estimations from distributed into lumped parameter systems. Two dynamic regimes were explored: (1) a power dynamics regime containing major inputs and outputs needed for overall plant control; and (2) a steam temperature dynamics scheme that considered consecutive superheater sections considered in terms of cooling water mass flow and steam mass flow. The single lumped parameters model was developed to provide temperature control for a fossil fuel-fired power plant. The design procedure used enthalpy to determine the plant's energy balance. The enthalpy curve was seen as a function of either temperature and steam pressure. A graphic simulation tool was used to optimize the model by comparing real and simulated plant data. The study showed that the amount of energy taken by the steam mass flow per time unit can be calculated by measuring temperatures and pressures at both ends of the superheater. An algorithm was then developed to determine the polynomial's coefficients according to best curve fitting over the training set and best maximum errors. It was concluded that a unified approach is now being developed to simulate and emulate the dynamics of steam temperature for each section's attemporator-superheater. 14 refs., 3 tabs., 5 figs.

  16. Life-Cycle Analysis of Greenhouse Gas Emissions and Water Consumption – Effects of Coal and Biomass Conversion to Liquid Fuels as Analyzed with the GREET Model

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qianfeng [Argonne National Lab. (ANL), Argonne, IL (United States); Cai, Hao [Argonne National Lab. (ANL), Argonne, IL (United States); Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-06-01

    The vast reserves of coal in the U.S. provide a significant incentive for the development of processes for coal conversion to liquid fuels (CTL). Also, CTL using domestic coal can help move the U.S. toward greater energy independence and security. However, current conversion technologies are less economically competitive and generate greater greenhouse gas (GHG) emissions than production of petroleum fuels. Altex Technologies Corporation (Altex, hereinafter) and Pennsylvania State University have developed a hybrid technology to produce jet fuel from a feedstock blend of coal and biomass. Collaborating with Altex, Argonne National Laboratory has expanded and used the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model to assess the life-cycle GHG emissions and water consumption of this hybrid technology. Biomass feedstocks include corn stover, switchgrass, and wheat straw. The option of biomass densification (bales to pellets) is also evaluated in this study. The results show that the densification process generates additional GHG emissions as a result of additional biomass process energy demand. This process coproduces a large amount of char, and this study investigates two scenarios to treat char: landfill disposal (Char-LF) and combustion for combined heat and power (CHP). Since the CHP scenarios export excess heat and electricity as coproducts, two coproduct handling methods are used for well-to-wake (WTWa) analysis: displacement (Char-CHP-Disp) and energy allocation (Char-CHP-EnAllo). When the feedstock contains 15 wt% densified wheat straw and 85 wt% lignite coal, WTWa GHG emissions of the coal-and-biomass-to-liquid pathways are 116, 97, and 137 gCO2e per megajoule (MJ) under the Char-LF, Char-CHP-Disp, and Char-CHP-EnAllo scenarios, respectively, as compared to conventional jet fuel production at 84 gCO2e/MJ. WTWa water consumption values are 0.072, -0.046, and 0.044 gal/MJ for Char-LF, Char-CHP-Disp, and Char

  17. Titan's greenhouse and antigreenhouse effects

    Science.gov (United States)

    Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

    1992-01-01

    Thermal mechanisms active in Titan's atmosphere are discussed in a brief review of data obtained during the Voyager I flyby in 1980. Particular attention is given to the greenhouse effect (GHE) produced by atmospheric H2, N2, and CH4; this GHE is stronger than that on earth, with CH4 and H2 playing roles similar to those of H2O and CO2 on earth. Also active on Titan is an antigreenhouse effect, in which dark-brown and orange organic aerosols block incoming solar light while allowing IR radiation from the Titan surface to escape. The combination of GHE and anti-GHE leads to a surface temperature about 12 C higher than it would be if Titan had no atmosphere.

  18. Greenhouse gas network design using backward Lagrangian particle dispersion modelling – Part 2: Sensitivity analyses and South African test case

    CSIR Research Space (South Africa)

    Nickless, A

    2014-05-01

    Full Text Available et al., 1999; Rödenbeck et al., 2003; Chevallier et al., 2010). This method relies on precision measurements of atmo- spheric CO2 to refine the prior estimates of the fluxes. Using this theory, an optimal network of new measurement sites... of the South African network design, these variables are produced by the CSIRO Conformal-Cubic Atmospheric Model (CCAM), a global circulation model. CCAM is a two time-level semi-implicit hydrostatic primi- tive equation developed by McGregor (1987) and later...

  19. 温室番茄果实生长模型的建立与实现%Fruit growth modeling and realization for greenhouse tomato

    Institute of Scientific and Technical Information of China (English)

    杨丽丽; 王一鸣; 董乔雪

    2013-01-01

    Fruit set is the key factor to crop yield and it has been a study focus so far. How to find an indicator that can reflect fruit set mechanism become more and more important. In this paper, utilized greenhouse tomato as a case to study the fruit set mechanism. Tomatoes were planted in solar greenhouse with four densities, environmental data and experiment data were recorded in detailed. Combined with math model, controlled environmental conditions of greenhouse and computer software design technology, the analysis were made to find the related factors which influence the fruit yield and dynamic fruit set rate for different plant density data. GreenLab model had particular advantage to simulate plant growth at organ level. With the help of GreenLab, the dynamic ratios of source to demand (i.e. Q/D) of biomass assimilation were output one growth cycle by one growth cycle. The relationship between the dynamic rate of fruit sets and the dynamic ratio of source to demand (i.e. Q/D) of biomass assimilation was built through the correlation analysis between observed data of dynamic fruit set and calculated Q/D value of model output. In order to computer programming and simulate, tomato topology structure was observed and plant topology generating rhythm was described as List data structure of Scilib language. This data structure can describe main stem and lateral axis alternative growth and syngenesis relationship between organs, so a plant topology structure in time sequence was produced. From the seeds, organs creation, biomass acquisition and partitioning were processed during the same growth cycle to insure feedback between organogenesis and photosynthesis. A global feedback dynamic fruit growth model was successfully built up. Following, independent data was used to validate the model. Both simulation data and measurement data of biomass and geometry size were close. The work provided a new research approach for crop yield. Introducing fruit set into mechanistic

  20. Alterações na temperatura do ar mediante telas nas laterais de ambientes protegidos cultivados com tomateiro Changes in air temperature due to side screens of greenhouses cultivated with tomato

    Directory of Open Access Journals (Sweden)

    Larissa A Duarte

    2011-02-01

    Full Text Available Este trabalho avaliou a influência do uso de telas anti-insetos nas laterais de ambientes protegidos sobre a temperatura do ar de um cultivo de tomate. O experimento foi realizado em Itajaí, SC (27º 34' S; 48º 30' W, no período de 17/03 a 25/07/2003, onde foram instalados quatro ambientes cobertos com filme plástico de PEBD, sendo que um deles não possuía revestimento lateral e três estavam revestidos lateralmente, cada um com um tipo de tela anti-insetos. As telas anti-insetos utilizadas foram: clarite (5 fios por cm, citros (10 fios por cm e antiafídeo (20 fios por cm. O ambiente revestido com tela antiafídeo nas laterais apresentou maiores valores de temperatura máxima do ar durante o outono-inverno, o que ocasionou aumento médio de 2,0 °C na temperatura média diária, quando comparado com o ambiente sem tela nas laterais. A variação da temperatura do ar nos ambientes com tela citros e clarite foi semelhante, apresentando ganho térmico diário de 0,4 °C em relação ao ambiente sem tela anti-insetos e possibilitou condições mais estáveis entre as temperaturas noturna e diurna para o cultivo do tomateiro nessa época do ano.This study aims to assess the influence of insect-proof screens installed in plastic greenhouses cultivated with tomato on the air temperature and crop yield. The experiment was conducted in Itajaí, SC, Brazil (27º 34' S; 48º 30' W, from 17/03 to 25/07/2003. Four greenhouses cultivated with tomato and all covered with polyethylene of low density (PEBD in the superior part were used. Three of these environments were covered laterally, each one with a different kind of screen: clarite insect-proof screens (12 meshes per cm, citros insect-proof screens (25 meshes per cm and afideo insect-proof screens (50 meshes per cm. The fourth environment did not receive any side coverage. The covered environment with afideo insect-proof screens on sides presented the highest maximum air temperatures during the

  1. Peritidal carbonate cycles induced by carbonate productivity variations:A conceptual model for an isolated Early Triassic greenhouse platform in South China

    Institute of Scientific and Technical Information of China (English)

    Wan Yang; Dan JLehrmann

    2014-01-01

    Eustasy has commonly been invoked to explain peritidal carbonate cyclicity, but is dififcult to explain cycles formed in a greenhouse climate when eustasy is minimal. We propose that peritidal cycles on an Early Triassic isolated carbonate platform in Guizhou, South China, were formed by hierarchical carbonate productivity variations. Most of the 149 shallowing-upward cycles are typically terminated by lfooding over intertidal facies and con-tain rare supratidal facies and no prolonged subaerial exposure. Low-diversity benthos in the platform interior during the post-end-Permian biotic recovery were sensitive to environmental perturbations, which caused variations in benthic sediment productivity in the subtidal carbon-ate factory. The perturbations may be driven by changes in salinity and degree of eutrophica-tion, or repeated platform mini-drowning by anoxic and/or CO2-charged deep water upwelled onto the banktop. They were modulated by Milankovitch orbitally-driven climatic and oceano-graphic factors as suggested by the hierarchical stacking pattern and spectral signals of these cycles. A one-dimensional conceptual model shows that hierarchical productivity variations alone may generate hierarchical peritidal carbonate cycles under conditions of constant sub-sidence and no sea-level lfuctuation.

  2. Peritidal carbonate cycles induced by carbonate productivity variations:A conceptual model for an isolated Early Triassic greenhouse platform in South China

    Institute of Scientific and Technical Information of China (English)

    Wan; Yang; Dan; J.Lehrmann

    2014-01-01

    Eustasy has commonly been invoked to explain peritidal carbonate cyclicity,but is difficult to explain cycles formed in a greenhouse climate when eustasy is minimal.We propose that peritidal cycles on an Early Triassic isolated carbonate platform in Guizhou,South China,were formed by hierarchical carbonate productivity variations.Most of the 149 shallowing-upward cycles are typically terminated by flooding over intertidal facies and contain rare supratidal facies and no prolonged subaerial exposure.Low-diversity benthos in the platform interior during the post-end-Permian biotic recovery were sensitive to environmental perturbations,which caused variations in benthic sediment productivity in the subtidal carbonate factory.The perturbations may be driven by changes in salinity and degree of eutrophication,or repeated platform mini-drowning by anoxic and/or CO2-charged deep water upwelled onto the banktop.They were modulated by Milankovitch orbitally-driven climatic and oceanographic factors as suggested by the hierarchical stacking pattern and spectral signals of these cycles.A one-dimensional conceptual model shows that hierarchical productivity variations alone may generate hierarchical peritidal carbonate cycles under conditions of constant subsidence and no sea-level fluctuation.

  3. The Influence of Climate, Soil and Pasture Type on Productivity and Greenhouse Gas Emissions Intensity of Modeled Beef Cow-Calf Grazing Systems in Southern Australia.

    Science.gov (United States)

    Bell, Matthew J; Cullen, Brendan R; Eckard, Richard J

    2012-10-01

    A biophysical whole farm system model was used to simulate the interaction between the historical climate, soil and pasture type at sites in southern Australia and assess the balance between productivity and greenhouse gas emissions (expressed in carbon dioxide equivalents, CO₂-eq.) intensity of beef cow-calf grazing systems. Four sites were chosen to represent a range of climatic zones, soil and pasture types. Poorer feed quality and supply limited the annual carrying capacity of the kikuyu pasture compared to phalaris pastures, with an average long-term carrying capacity across sites estimated to be 0.6 to 0.9 cows/ha. A relative reduction in level of feed intake to productivity of calf live weight/ha at weaning by feeding supplementary feed reduced the average CO₂-eq. emissions/kg calf live weight at weaning of cows on the kikuyu pasture (18.4 and 18.9 kg/kg with and without supplementation, respectively), whereas at the other sites studied an increase in intake level to productivity and emission intensity was seen (between 10.4 to 12.5 kg/kg without and with supplementary feed, respectively). Enteric fermentation and nitrous oxide emissions from denitrification were the main sources of annual variability in emissions intensity, particularly at the lower rainfall sites. Emissions per unit product of low input systems can be minimized by efficient utilization of pasture to maximize the annual turnoff of weaned calves and diluting resource input per unit product.

  4. Methane as a greenhouse gas: a simulation model of the atmospheric chemistry of the Ch-4-CO-OH cycle

    NARCIS (Netherlands)

    Rotmans J; Eggink E

    1988-01-01

    In deze studie wordt de rol van methaan (CH-4) als broeikasgas onderzocht. Hiervoor is een simulatiemodel ontwikkeld, wat naast CH-4 ook koolmonixide (CO) en hydroxyl (OH) bevat. Dit model vormt een onafhankelijke module binnen IMAGE. In de betreffende methaanmodule worden, aan de hand van vier

  5. An Introduction to Greenhouse Production. Second Edition.

    Science.gov (United States)

    McMahon, Robert W.

    This student manual is presented in its first revision, providing a current, basic text for those preparing for greenhouse and floriculture work. Its fourteen chapters are: Overview of the Greenhouse Industry; Greenhouse Structures; Controlling the Greenhouse Environment; Greenhouse Equipment and Lighting; Greenhouse Irrigation Systems; Root Media…

  6. River water temperature and fish growth forecasting models

    Science.gov (United States)

    Danner, E.; Pike, A.; Lindley, S.; Mendelssohn, R.; Dewitt, L.; Melton, F. S.; Nemani, R. R.; Hashimoto, H.

    2010-12-01

    Water is a valuable, limited, and highly regulated resource throughout the United States. When making decisions about water allocations, state and federal water project managers must consider the short-term and long-term needs of agriculture, urban users, hydroelectric production, flood control, and the ecosystems downstream. In the Central Valley of California, river water temperature is a critical indicator of habitat quality for endangered salmonid species and affects re-licensing of major water projects and dam operations worth billions of dollars. There is consequently strong interest in modeling water temperature dynamics and the subsequent impacts on fish growth in such regulated rivers. However, the accuracy of current stream temperature models is limited by the lack of spatially detailed meteorological forecasts. To address these issues, we developed a high-resolution deterministic 1-dimensional stream temperature model (sub-hourly time step, sub-kilometer spatial resolution) in a state-space framework, and applied this model to Upper Sacramento River. We then adapted salmon bioenergetics models to incorporate the temperature data at sub-hourly time steps to provide more realistic estimates of salmon growth. The temperature model uses physically-based heat budgets to calculate the rate of heat transfer to/from the river. We use variables provided by the TOPS-WRF (Terrestrial Observation and Prediction System - Weather Research and Forecasting) model—a high-resolution assimilation of satellite-derived meteorological observations and numerical weather simulations—as inputs. The TOPS-WRF framework allows us to improve the spatial and temporal resolution of stream temperature predictions. The salmon growth models are adapted from the Wisconsin bioenergetics model. We have made the output from both models available on an interactive website so that water and fisheries managers can determine the past, current and three day forecasted water temperatures at

  7. Greenhouse gas network design using backward Lagrangian particle dispersion modelling − Part 1: Methodology and Australian test case

    Directory of Open Access Journals (Sweden)

    T. Ziehn

    2014-09-01

    Full Text Available This paper describes the generation of optimal atmospheric measurement networks for determining carbon dioxide fluxes over Australia using inverse methods. A Lagrangian particle dispersion model is used in reverse mode together with a Bayesian inverse modelling framework to calculate the relationship between weekly surface fluxes, comprising contributions from the biosphere and fossil fuel combustion, and hourly concentration observations for the Australian continent. Meteorological driving fields are provided by the regional version of the Australian Community Climate and Earth System Simulator (ACCESS at 12 km resolution at an hourly timescale. Prior uncertainties are derived on a weekly timescale for biosphere fluxes and fossil fuel emissions from high-resolution model runs using the Community Atmosphere Biosphere Land Exchange (CABLE model and the Fossil Fuel Data Assimilation System (FFDAS respectively. The influence from outside the modelled domain is investigated, but proves to be negligible for the network design. Existing ground-based measurement stations in Australia are assessed in terms of their ability to constrain local flux estimates from the land. We find that the six stations that are currently operational are already able to reduce the uncertainties on surface flux estimates by about 30%. A candidate list of 59 stations is generated based on logistic constraints and an incremental optimisation scheme is used to extend the network of existing stations. In order to achieve an uncertainty reduction of about 50%, we need to double the number of measurement stations in Australia. Assuming equal data uncertainties for all sites, new stations would be mainly located in the northern and eastern part of the continent.

  8. Greenhouse gas network design using backward Lagrangian particle dispersion modelling - Part 1: Methodology and Australian test case

    Science.gov (United States)

    Ziehn, T.; Nickless, A.; Rayner, P. J.; Law, R. M.; Roff, G.; Fraser, P.

    2014-09-01

    This paper describes the generation of optimal atmospheric measurement networks for determining carbon dioxide fluxes over Australia using inverse methods. A Lagrangian particle dispersion model is used in reverse mode together with a Bayesian inverse modelling framework to calculate the relationship between weekly surface fluxes, comprising contributions from the biosphere and fossil fuel combustion, and hourly concentration observations for the Australian continent. Meteorological driving fields are provided by the regional version of the Australian Community Climate and Earth System Simulator (ACCESS) at 12 km resolution at an hourly timescale. Prior uncertainties are derived on a weekly timescale for biosphere fluxes and fossil fuel emissions from high-resolution model runs using the Community Atmosphere Biosphere Land Exchange (CABLE) model and the Fossil Fuel Data Assimilation System (FFDAS) respectively. The influence from outside the modelled domain is investigated, but proves to be negligible for the network design. Existing ground-based measurement stations in Australia are assessed in terms of their ability to constrain local flux estimates from the land. We find that the six stations that are currently operational are already able to reduce the uncertainties on surface flux estimates by about 30%. A candidate list of 59 stations is generated based on logistic constraints and an incremental optimisation scheme is used to extend the network of existing stations. In order to achieve an uncertainty reduction of about 50%, we need to double the number of measurement stations in Australia. Assuming equal data uncertainties for all sites, new stations would be mainly located in the northern and eastern part of the continent.

  9. On the fate of the Standard Model at finite temperature

    CERN Document Server

    Rose, Luigi Delle; Urbano, Alfredo

    2015-01-01

    In this paper we revisit and update the computation of thermal corrections to the stability of the electroweak vacuum in the Standard Model. At zero temperature, we make use of the full two-loop effective potential, improved by three-loop beta functions with two-loop matching conditions. At finite temperature, we include one-loop thermal corrections together with resummation of daisy diagrams. We solve numerically---both at zero and finite temperature---the bounce equation, thus providing an accurate description of the thermal tunneling. We find that at finite temperature the instability bound excludes values of the top mass $M_t \\gtrsim 173.6$ GeV, assuming $M_h \\simeq 125$ GeV and including uncertainties on the strong coupling. We discuss the validity and temperature-dependence of this bound in the early Universe, with a special focus on the reheating phase after inflation.

  10. Moisture Absorption Model of Composites Considering Water Temperature Effect

    Directory of Open Access Journals (Sweden)

    HUI Li

    2016-11-01

    Full Text Available The influence of water temperature on composite moisture absorption parameters was investigated in temperature-controlled water bath. Experiments of carbon fiber/bismaleimide resin composites immersed in water of 60℃, 70℃and 80℃ were developed respectively. According to the moisture content-time curves obtained from the experimental results, the diffusion coefficient and the balanced moisture content of the composites immersed in different water temperature could be calculated. What's more, the effect of water temperature on the diffusion coefficient and the balanced moisture content were discussed too. According to the Arrhenius equation and the law of Fick, a moisture absorption model was proposed to simulate the hygroscopic behaviour of the composite laminates immersed in different water temperature which can predict the absorption rate of water of the composites immersed in distilled water of 95℃ at any time precisely and can calculate how long it will take to reach the specific absorption rate.

  11. Modeling the melting temperature of nanoscaled bimetallic alloys.

    Science.gov (United States)

    Li, Ming; Zhu, Tian-Shu

    2016-06-22

    The effect of size, composition and dimension on the melting temperature of nanoscaled bimetallic alloys was investigated by considering the interatomic interaction. The established thermodynamics model without any arbitrarily adjustable parameters can be used to predict the melting temperature of nanoscaled bimetallic alloys. It is found that, the melting temperature and interatomic interaction of nanoscaled bimetallic alloys decrease with the decrease in size and the increasing composition of the lower surface energy metal. Moreover, for the nanoscaled bimetallic alloys with the same size and composition, the dependence of the melting temperature on the dimension can be sequenced as follows: nanoparticles > nanowires > thin films. The accuracy of the developed model is verified by the recent experimental and computer simulation results.

  12. A model of the ground surface temperature for micrometeorological analysis

    Science.gov (United States)

    Leaf, Julian S.; Erell, Evyatar

    2017-07-01

    Micrometeorological models at various scales require ground surface temperature, which may not always be measured in sufficient spatial or temporal detail. There is thus a need for a model that can calculate the surface temperature using only widely available weather data, thermal properties of the ground, and surface properties. The vegetated/permeable surface energy balance (VP-SEB) model introduced here requires no a priori knowledge of soil temperature or moisture at any depth. It combines a two-layer characterization of the soil column following the heat conservation law with a sinusoidal function to estimate deep soil temperature, and a simplified procedure for calculating moisture content. A physically based solution is used for each of the energy balance components allowing VP-SEB to be highly portable. VP-SEB was tested using field data measuring bare loess desert soil in dry weather and following rain events. Modeled hourly surface temperature correlated well with the measured data (r 2 = 0.95 for a whole year), with a root-mean-square error of 2.77 K. The model was used to generate input for a pedestrian thermal comfort study using the Index of Thermal Stress (ITS). The simulation shows that the thermal stress on a pedestrian standing in the sun on a fully paved surface, which may be over 500 W on a warm summer day, may be as much as 100 W lower on a grass surface exposed to the same meteorological conditions.

  13. Integrated flow and temperature modeling at the catchment scale

    DEFF Research Database (Denmark)

    Loinaz, Maria Christina; Davidsen, Hasse Kampp; Butts, Michael

    2013-01-01

    , the Silver Creek Basin in Idaho, where stream temperature affects the populations of fish and other aquatic organisms. The model calibration highlights the importance of spatially distributed flow dynamics in the catchment to accurately predict stream temperatures. The results also show the value...... Creek over 0.3°C and 1.5°C, respectively. In spring-fed systems like Silver Creek, it is clearly not feasible to separate river habitat restoration from upstream catchment and groundwater management....

  14. Dielectric barrier discharges used for the conversion of greenhouse gases: modeling the plasma chemistry by fluid simulations

    Energy Technology Data Exchange (ETDEWEB)

    De Bie, Christophe; Martens, Tom; Bogaerts, Annemie [Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Van Dijk, Jan [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Paulussen, Sabine; Verheyde, Bert [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Corthals, Steven, E-mail: annemie.bogaerts@ua.ac.b [Centre for Surface Chemistry and Catalysis, K. U. Leuven, Kasteelpark Arenberg 23, 3001 Heverlee (Belgium)

    2011-04-15

    The conversion of methane to value-added chemicals and fuels is considered to be one of the challenges of the 21st century. In this paper we study, by means of fluid modeling, the conversion of methane to higher hydrocarbons or oxygenates by partial oxidation with CO{sub 2} or O{sub 2} in a dielectric barrier discharge. Sixty-nine different plasma species (electrons, ions, molecules, radicals) are included in the model, as well as a comprehensive set of chemical reactions. The calculation results presented in this paper include the conversion of the reactants and the yields of the reaction products as a function of residence time in the reactor, for different gas mixing ratios. Syngas (i.e. H{sub 2} + CO) and higher hydrocarbons (C{sub 2}H{sub x}) are typically found to be important reaction products.

  15. Dynamic and Static Behaviour with Respect to Energy Use and Investment of Dutch Greenhouse Firms

    NARCIS (Netherlands)

    Verreth, D.M.I.; Emvalomatis, G.; Bunte, F.H.J.; Oude Lansink, A.G.J.M.

    2015-01-01

    Dutch greenhouse horticulture firms are energy-intensive and major emitters of greenhouse gases. This paper develops a theoretically consistent model that is able to describe the greenhouse firms’ behaviour regarding energy use and investments in energy technology. The behaviour of the firm is model

  16. Friedberg-Lee model at finite temperature and density

    Science.gov (United States)

    Mao, Hong; Yao, Minjie; Zhao, Wei-Qin

    2008-06-01

    The Friedberg-Lee model is studied at finite temperature and density. By using the finite temperature field theory, the effective potential of the Friedberg-Lee model and the bag constant B(T) and B(T,μ) have been calculated at different temperatures and densities. It is shown that there is a critical temperature TC≃106.6 MeV when μ=0 MeV and a critical chemical potential μ≃223.1 MeV for fixing the temperature at T=50 MeV. We also calculate the soliton solutions of the Friedberg-Lee model at finite temperature and density. It turns out that when T⩽TC (or μ⩽μC), there is a bag constant B(T) [or B(T,μ)] and the soliton solutions are stable. However, when T>TC (or μ>μC) the bag constant B(T)=0 MeV [or B(T,μ)=0 MeV] and there is no soliton solution anymore, therefore, the confinement of quarks disappears quickly.

  17. The Friedberg-Lee model at finite temperature and density

    CERN Document Server

    Mao, Hong; Zhao, Wei-Qin

    2007-01-01

    The Friedberg-Lee model is studied at finite temperature and density. By using the finite temperature field theory, the effective potential of the Friedberg-Lee model and the bag constant $B(T)$ and $B(T,\\mu)$ have been calculated at different temperatures and densities. It is shown that there is a critical temperature $T_{C}\\simeq 106.6 \\mathrm{MeV}$ when $\\mu=0 \\mathrm{MeV}$ and a critical chemical potential $\\mu \\simeq 223.1 \\mathrm{MeV}$ for fixing the temperature at $T=50 \\mathrm{MeV}$. We also calculate the soliton solutions of the Friedberg-Lee model at finite temperature and density. It turns out that when $T\\leq T_{C}$ (or $\\mu \\leq \\mu_C$), there is a bag constant $B(T)$ (or $B(T,\\mu)$) and the soliton solutions are stable. However, when $T>T_{C}$ (or $\\mu>\\mu_C$) the bag constant $B(T)=0 \\mathrm{MeV}$ (or $B(T,\\mu)=0 \\mathrm{MeV}$) and there is no soliton solution anymore, therefore, the confinement of quarks disappears quickly.

  18. REFINEMENT OF THE STREAM TEMPERATURE NETWORK MODEL WITH CORRECTIONS FOR SOLAR SHADINGS AND INFLOW TEMPERATURES

    Science.gov (United States)

    Miyamoto, Hitoshi; Maeba, Hiroshi; Nakayama, Kazuya; Michioku, Kohji

    A basin-wide stream network model was developed for stream temperature prediction in a river basin. The model used Horton’s geomorphologic laws for channel networks and river basins with stream ordering systems in order to connect channel segments from sources to the river mouth. Within the each segment, a theoretical solution derived from a thermal energy equation was used to predict longitudinal variation of stream temperatures. The model also took into account effects of solar radiation reduction due to both riparian vegetation and topography, thermal advection from the sources and lateral land-use. Comparison of the model prediction with observation in the Ibo River Basin of Japan showed very good agreement for the thermal structure throughout the river basin for almost all seasons, excluding the autumnal month in which the thermal budget on the stream water body was changed from positive to negative.

  19. SAFT-γ force field for the simulation of molecular fluids: 2. Coarse-grained models of greenhouse gases, refrigerants, and long alkanes.

    Science.gov (United States)

    Avendaño, Carlos; Lafitte, Thomas; Adjiman, Claire S; Galindo, Amparo; Müller, Erich A; Jackson, George

    2013-03-07

    In the first paper of this series [C. Avendaño, T. Lafitte, A. Galindo, C. S. Adjiman, G. Jackson, and E. A. Müller, J. Phys. Chem. B2011, 115, 11154] we introduced the SAFT-γ force field for molecular simulation of fluids. In our approach, a molecular-based equation of state (EoS) is used to obtain coarse-grained (CG) intermolecular potentials that can then be employed in molecular simulation over a wide range of thermodynamic conditions of the fluid. The macroscopic experimental data for the vapor-liquid equilibria (saturated liquid density and vapor pressure) of a given system are represented with the SAFT-VR Mie EoS and used to estimate effective intermolecular parameters that provide a good description of the thermodynamic properties by exploring a wide parameter space for models based on the Mie (generalized Lennard-Jones) potential. This methodology was first used to develop a simple single-segment CG Mie model of carbon dioxide (CO2) which allows for a reliable representation of the fluid-phase equilibria (for which the model was parametrized), as well as an accurate prediction of other properties such as the enthalpy of vaporization, interfacial tension, supercritical density, and second-derivative thermodynamic properties (thermal expansivity, isothermal compressibility, heat capacity, Joule-Thomson coefficient, and speed of sound). In our current paper, the methodology is further applied and extended to develop effective SAFT-γ CG Mie force fields for some important greenhouse gases including carbon tetrafluoride (CF4) and sulfur hexafluoride (SF6), modeled as simple spherical molecules, and for long linear alkanes including n-decane (n-C10H22) and n-eicosane (n-C20H42), modeled as homonuclear chains of spherical Mie segments. We also apply the SAFT-γ methodology to obtain a CG homonuclear two-segment Mie intermolecular potential for the more challenging polar and asymmetric compound 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf), a novel replacement

  20. Heat Transfer Modeling for Rigid High-Temperature Fibrous Insulation

    Science.gov (United States)

    Daryabeigi, Kamran; Cunnington, George R.; Knutson, Jeffrey R.

    2012-01-01

    Combined radiation and conduction heat transfer through a high-temperature, high-porosity, rigid multiple-fiber fibrous insulation was modeled using a thermal model previously used to model heat transfer in flexible single-fiber fibrous insulation. The rigid insulation studied was alumina enhanced thermal barrier (AETB) at densities between 130 and 260 kilograms per cubic meter. The model consists of using the diffusion approximation for radiation heat transfer, a semi-empirical solid conduction model, and a standard gas conduction model. The relevant parameters needed for the heat transfer model were estimated from steady-state thermal measurements in nitrogen gas at various temperatures and environmental pressures. The heat transfer modeling methodology was evaluated by comparison with standard thermal conductivity measurements, and steady-state thermal measurements in helium and carbon dioxide gases. The heat transfer model is applicable over the temperature range of 300 to 1360 K, pressure range of 0.133 to 101.3 x 10(exp 3) Pa, and over the insulation density range of 130 to 260 kilograms per cubic meter in various gaseous environments.

  1. Phase behaviors and membrane properties of model liposomes: Temperature effect

    Science.gov (United States)

    Wu, Hsing-Lun; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2014-09-01

    The phase behaviors and membrane properties of small unilamellar vesicles have been explored at different temperatures by dissipative particle dynamics simulations. The vesicles spontaneously formed by model lipids exhibit pre-transition from gel to ripple phase and main transition from ripple to liquid phase. The vesicle shape exhibits the faceted feature at low temperature, becomes more sphere-like with increasing temperature, but loses its sphericity at high temperature. As the temperature rises, the vesicle size grows but the membrane thickness declines. The main transition (Tm) can be identified by the inflection point. The membrane structural characteristics are analyzed. The inner and outer leaflets are asymmetric. The length of the lipid tail and area density of the lipid head in both leaflets decrease with increasing temperature. However, the mean lipid volume grows at low temperature but declines at high temperature. The membrane mechanical properties are also investigated. The water permeability grows exponentially with increasing T but the membrane tension peaks at Tm. Both the bending and stretching moduli have their minima near Tm. Those results are consistent with the experimental observations, indicating that the main signatures associated with phase transition are clearly observed in small unilamellar vesicles.

  2. Estudo preliminar do controle biológico da traça-do-tomateiro com o parasitóide Trichogramma pretiosum em ambientes protegidos A preliminar survey on the biological control of South American tomato pinworm with the parasitoid Trichogramma pretiosum in greenhouse models

    Directory of Open Access Journals (Sweden)

    Maria Alice de Medeiros

    2009-03-01

    ógico permitiu a produção de tomates por doze semanas em todas as casas de vegetação testadas; c de acordo com a análise econômica, o tomate produzido em casa de vegetação tipo convectivo apresentou melhor rendimento.Greenhouse tomato cropping is economically advantageous for the producers. However, the hot and dry environment inside the greenhouse is conducive to tomato pinworm Tuta absoluta (Meyrick population growth and as a consequence it is difficult to control the pest. Nowadays, the pest is controlled mainly by insecticides. The biological control using the parasitoid Trichogramma pretiosum Riley is pointed out as one of those alternative methods and was evaluated in greenhouse. Experiments were carried out in stacked plants of tomato cv. Larissa, in three greenhouse roof models: arc, chapel and convective, with 288 plants in a 160m² area in each type of greenhouse. All treatments were associated with weekly sprays of Bacillus thuringiensis and weekly release of the parasitoid: 1 convective greenhouse: one single release of 200 cm² of parasitized eggs, once a week; 2 arc roof greenhouse: release of 200 cm² of parasitized eggs twice a week, 100 cm² in each release; 3 chapel greenhouse model 400 cm² of parasitized eggs release twice a week, 200 cm² in each release. Once a week, 50 leaflets were collected in each greenhouse. The number of eggs/leaf was determined in the laboratory and then the eggs were kept individually in a chamber in order to determine the number of emerged larvae or the number of parasitized eggs. Tomato production and damage to the fruits were determined weekly in 50 tomato plants randomly chosen in each treatment. The technical and economic efficiency of production system were analyzed in the different greenhouse models. The main results were: a different conditions of temperature and humidity affected parasitoid performance, b biological control technique provided tomato production for twelve weeks in all greenhouse tested; c the tomato

  3. Greenhouse gases and the metallurgical process industry

    Energy Technology Data Exchange (ETDEWEB)

    Lupis, C.H.P.

    1999-10-01

    The present lecture offers a brief review of the greenhouse effect, the sources of greenhouse gases, the potential effect of these gases on global warming, the response of the international community, and the probable cost of national compliance. The specific emissions of the metallurgical process industry, particularly those of the steel and aluminum sectors, are then examined. The potential applications of life-cycle assessments and of an input-output model in programs of emissions' abatement are investigated, and, finally, a few remarks on some implications for education are presented.

  4. Multi-Model CIMP5 projected impacts of increased greenhouse gases on the Niger basin and implications for hydropower production

    Science.gov (United States)

    Oyerinde, Ganiyu; Wisser, Dominik

    2014-05-01

    Climate change could potentially have large impacts on water availability in West Africa and the predictions are accrued with high uncertainties in this region. Countries in the Niger River basin (West Africa) plan the investment of 200 million in the installation of an additional 400MW of hydropower in the nearest future, adding to the existing 685MW. With the impacts of climate change in the basin already occurring, there is a need for comprehending the influence of future hydro-climatic changes on water resources and hydro-power generation in the basin. This study uses a hydrological model to simulate river flow under present and future conditions and evaluates the impacts of potential changes on electricity production of the largest hydroelectric dam (Kainji) in the Niger Basin. The Kainji reservoir produces 25 per cent of the current energy needs of Nigeria and was subject to large fluctuations in energy production as a result of variable inflow and operational reasons. Inflow into the reservoir was simulated using hydroclimatic data from a set of 7 regional climate models (RCM) with two emission scenarios from the CORDEX-Africa regional downscaling experiment, driven with CMIP5 data. Based on observations of inflow, water level in the reservoir, and energy production we developed a simple hydroelectricity production model to simulate future energy production for the reservoir. Results suggest increases in river flow for the majority of RCM data as a result of increases in precipitation in the headwaters of the basin around 2050 and slightly decreasing trends for low emission scenarios by the end of the century. Despite this consistent increase, shifts in timing of river flow can challenge the reliable production of energy. This analysis could help assess the planning of hydropower schemes in the basin for a sustainable production of hydroelectricity in the future.

  5. Temperature response functions introduce high uncertainty in modelled carbon stocks in cold temperature regimes

    Directory of Open Access Journals (Sweden)

    H. Portner

    2009-08-01

    Full Text Available Models of carbon cycling in terrestrial ecosystems contain formulations for the dependence of respiration on temperature, but the sensitivity of predicted carbon pools and fluxes to these formulations and their parameterization is not understood. Thus, we made an uncertainty analysis of soil organic matter decomposition with respect to its temperature dependency using the ecosystem model LPJ-GUESS.

    We used five temperature response functions (Exponential, Arrhenius, Lloyd-Taylor, Gaussian, Van't Hoff. We determined the parameter uncertainty ranges of the functions by nonlinear regression analysis based on eight experimental datasets from northern hemisphere ecosystems. We sampled over the uncertainty bounds of the parameters and run simulations for each pair of temperature response function and calibration site. The uncertainty in both long-term and short-term soil carbon dynamics was analyzed over an elevation gradient in southern Switzerland.

    The function of Lloyd-Taylor turned out to be adequate for modelling the temperature dependency of soil organic matter decomposition, whereas the other functions either resulted in poor fits (Exponential, Arrhenius or were not applicable for all datasets (Gaussian, Van't Hoff. There were two main sources of uncertainty for model simulations: (1 the uncertainty in the parameter estimates of the response functions, which increased with increasing temperature and (2 the uncertainty in the simulated size of carbon pools, which increased with elevation, as slower turn-over times lead to higher carbon stocks and higher associated uncertainties. The higher uncertainty in carbon pools with slow turn-over rates has important implications for the uncertainty in the projection of the change of soil carbon stocks driven by climate change, which turned out to be more uncertain for higher elevations and hence higher latitudes, which are of key importance for the global terrestrial carbon

  6. Energy based model for temperature dependent behavior of ferromagnetic materials

    Science.gov (United States)

    Sah, Sanjay; Atulasimha, Jayasimha

    2017-03-01

    An energy based model for temperature dependent anhysteretic magnetization curves of ferromagnetic materials is proposed and benchmarked against experimental data. This is based on the calculation of macroscopic magnetic properties by performing an energy weighted average over all possible orientations of the magnetization vector. Most prior approaches that employ this method are unable to independently account for the effect of both inhomogeneity and temperature in performing the averaging necessary to model experimental data. Here we propose a way to account for both effects simultaneously and benchmark the model against experimental data from 5 K to 300 K for two different materials in both annealed (fewer inhomogeneities) and deformed (more inhomogeneities) samples. This demonstrates that this framework is well suited to simulate temperature dependent experimental magnetic behavior.

  7. An exospheric temperature model from CHAMP thermospheric density

    Science.gov (United States)

    Weng, Libin; Lei, Jiuhou; Sutton, Eric; Dou, Xiankang; Fang, Hanxian

    2017-02-01

    In this study, the effective exospheric temperature, named as T∞, derived from thermospheric densities measured by the CHAMP satellite during 2002-2010 was utilized to develop an exospheric temperature model (ETM) with the aid of the NRLMSISE-00 model. In the ETM, the temperature variations are characterized as a function of latitude, local time, season, and solar and geomagnetic activities. The ETM is validated by the independent GRACE measurements, and it is found that T∞ and thermospheric densities from the ETM are in better agreement with the GRACE data than those from the NRLMSISE-00 model. In addition, the ETM captures well the thermospheric equatorial anomaly feature, seasonal variation, and the hemispheric asymmetry in the thermosphere.

  8. Searching for solutions to mitigate greenhouse gas emissions by agricultural policy decisions — Application of system dynamics modeling for the case of Latvia

    Energy Technology Data Exchange (ETDEWEB)

    Dace, Elina, E-mail: elina.dace@rtu.lv [Institute of Energy Systems and Environment, Riga Technical University, Azenes 12/1, Riga LV1048 (Latvia); Muizniece, Indra; Blumberga, Andra [Institute of Energy Systems and Environment, Riga Technical University, Azenes 12/1, Riga LV1048 (Latvia); Kaczala, Fabio [Department of Biology and Environmental Science, Faculty of Health & Life Sciences, Linnaeus University, SE-39182 Kalmar (Sweden)

    2015-09-15

    European Union (EU) Member States have agreed to limit their greenhouse gas (GHG) emissions from sectors not covered by the EU Emissions Trading Scheme (non-ETS). That includes also emissions from agricultural sector. Although the Intergovernmental Panel on Climate Change (IPCC) has established a methodology for assessment of GHG emissions from agriculture, the forecasting options are limited, especially when policies and their interaction with the agricultural system are tested. Therefore, an advanced tool, a system dynamics model, was developed that enables assessment of effects various decisions and measures have on agricultural GHG emissions. The model is based on the IPCC guidelines and includes the main elements of an agricultural system, i.e. land management, livestock farming, soil fertilization and crop production, as well as feedback mechanisms between the elements. The case of Latvia is selected for simulations, as agriculture generates 22% of the total anthropogenic GHG emissions in the country. The results demonstrate that there are very limited options for GHG mitigation in the agricultural sector. Thereby, reaching the non-ETS GHG emission targets will be very challenging for Latvia, as the level of agricultural GHG emissions will be exceeded considerably above the target levels. Thus, other non-ETS sectors will have to reduce their emissions drastically to “neutralize” the agricultural sector's emissions for reaching the EU's common ambition to move towards low-carbon economy. The developed model may serve as a decision support tool for impact assessment of various measures and decisions on the agricultural system's GHG emissions. Although the model is applied to the case of Latvia, the elements and structure of the model developed are similar to agricultural systems in many countries. By changing numeric values of certain parameters, the model can be applied to analyze decisions and measures in other countries. - Highlights:

  9. Detection of Greenhouse-Gas-Induced Climatic Change

    Energy Technology Data Exchange (ETDEWEB)

    Jones, P.D.; Wigley, T.M.L.

    1998-05-26

    The objective of this report is to assemble and analyze instrumental climate data and to develop and apply climate models as a basis for (1) detecting greenhouse-gas-induced climatic change, and (2) validation of General Circulation Models.

  10. Modeling of the climate system and of its response to a greenhouse effect increase; Modelisation du systeme climatique et de sa reponse a une augmentation de l'effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    Li, L. [Universite Pierre et Marie Curie, CNRS, Lab. de Meteorologie Dynamique, 75 - Paris (France)

    2005-07-01

    The anthropic disturbance of the Earth's greenhouse effect is already visible and will enhance in the coming years or decades. In front of the rapidity and importance of the global warming effect, the socio-economical management of this change will rise problems and must be studied by the scientific community. At the modeling level, finding a direct strategy for the validation of climate models is not easy: many uncertainties exist because energy transformations take place at a low level and several processes take place at the same time. The variability observed at the seasonal, inter-annual or paleo- scales allows to validate the models at the process level but not the evolution of the whole system. The management of these uncertainties is an integral part of the global warming problem. Thus, several scenarios can be proposed and their risk of occurrence must be estimated. This paper presents first the greenhouse effect, the climatic changes during geologic times, the anthropic disturbance of the greenhouse effect, the modeling of climate and the forecasting of its evolution. (J.S.)

  11. Greenhouse role in reef stress unproven

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, L.

    1991-07-19

    In the late 1980s, as coral reefs throughout the Caribbean and elsewhere fell victim to a phenomenon known as bleaching, a few scientists stated that greenhouse warming is upon us and that the exquisitely sensitive corals, reacting to elevated water temperatures, are serving as biological sentinels. This stirred up so much concern that Congress assigned the National Science Foundation (NSF) to investigate the connection between coral bleaching and global warming. Late last month investigators at an NSF-sponsored meeting rendered their verdict. Following the Miami meeting, which brought together, for the first time, climatologists, oceanographers, and meteorologists with marine biologists, ecologists, and other reef experts, the participants issued a statement saying essentially that, yes, higher temperatures seem to be at least partly at fault but, no, greenhouse warming cannot be blamed.

  12. Greenhouse gas network design using backward Lagrangian particle dispersion modelling – Part 2: Sensitivity analyses and South African test case

    Directory of Open Access Journals (Sweden)

    A. Nickless

    2014-05-01

    Full Text Available This is the second part of a two-part paper considering network design based on a Lagrangian stochastic particle dispersion model (LPDM, aimed at reducing the uncertainty of the flux estimates achievable for the region of interest by the continuous observation of atmospheric CO2 concentrations at fixed monitoring stations. The LPDM model, which can be used to derive the sensitivity matrix used in an inversion, was run for each potential site for the months of July (representative of the Southern Hemisphere Winter and January (Summer. The magnitude of the boundary contributions to each potential observation site was tested to determine its inclusion in the network design, but found to be minimal. Through the use of the Bayesian inverse modelling technique, the sensitivity matrix, together with the prior estimates for the covariance matrices of the observations and surface fluxes were used to calculate the posterior covariance matrix of the estimated fluxes, used for the calculation of the cost function of the optimisation procedure. The optimisation procedure was carried out for South Africa under a standard set of conditions, similar to those applied to the Australian test case in Part 1, for both months and for the combined two months. The conditions were subtly changed, one at a time, and the optimisation routine re-run under each set of modified conditions, and compared to the original optimal network design. The results showed that changing the height of the surface grid cells, including an uncertainty estimate for the oceans, or increasing the night time observational uncertainty did not result in any major changes in the positioning of the stations relative to the basic design, but changing the covariance matrix or increasing the spatial resolution did. The genetic algorithm was able to find a slightly better solution than the incremental optimisation procedure, but did not drastically alter the solution compared to the standard case

  13. Modeling temperature inversion in southeastern Yellow Sea during winter 2016

    Science.gov (United States)

    Pang, Ig-Chan; Moon, Jae-Hong; Lee, Joon-Ho; Hong, Ji-Seok; Pang, Sung-Jun

    2017-05-01

    A significant temperature inversion with temperature differences larger than 3°C was observed in the southeastern Yellow Sea (YS) during February 2016. By analyzing in situ hydrographic profiles and results from a regional ocean model for the YS, this study examines the spatiotemporal evolution of the temperature inversion and its connection with wind-induced currents in winter. Observations reveal that in winter, when the northwesterly wind prevails over the YS, the temperature inversion occurs largely at the frontal zone southwest of Korea where warm/saline water of a Kuroshio origin meets cold/fresh coastal water. Our model successfully captures the temperature inversion observed in the winter of 2016 and suggests a close relation between northwesterly wind bursts and the occurrence of the large inversion. In this respect, the strong northwesterly wind drove cold coastal water southward in the upper layer via Ekman transport, which pushed the water mass southward and increased the sea level slope in the frontal zone in southeastern YS. The intensified sea level slope propagated northward away from the frontal zone as a shelf wave, causing a northward upwind flow response along the YS trough in the lower layer, thereby resulting in the large temperature inversion. Diagnostic analysis of the momentum balance shows that the westward pressure gradient, which developed with shelf wave propagation along the YS trough, was balanced with the Coriolis force in accordance with the northward upwind current in and around the inversion area.

  14. A complex autoregressive model and application to monthly temperature forecasts

    Directory of Open Access Journals (Sweden)

    X. Gu

    2005-11-01

    Full Text Available A complex autoregressive model was established based on the mathematic derivation of the least squares for the complex number domain which is referred to as the complex least squares. The model is different from the conventional way that the real number and the imaginary number are separately calculated. An application of this new model shows a better forecast than forecasts from other conventional statistical models, in predicting monthly temperature anomalies in July at 160 meteorological stations in mainland China. The conventional statistical models include an autoregressive model, where the real number and the imaginary number are separately disposed, an autoregressive model in the real number domain, and a persistence-forecast model.

  15. Greenhouse effect due to atmospheric nitrous oxide

    Science.gov (United States)

    Yung, Y. L.; Wang, W. C.; Lacis, A. A.

    1976-01-01

    The greenhouse effect due to nitrous oxide in the present atmosphere is about 0.8 K. Increase in atmospheric N2O due to perturbation of the nitrogen cycle by man may lead to an increase in surface temperature as large as 0.5 K by 2025, or 1.0 K by 2100. Other climatic effects of N2O are briefly discussed.

  16. Tests of the improved Weiland ion temperature gradient transport model

    Energy Technology Data Exchange (ETDEWEB)

    Kinsey, J.E.; Bateman, G.; Kritz, A.H. [Lehigh Univ., Bethlehem, PA (United States)] [and others

    1996-12-31

    The Weiland theoretically derived transport model for ion temperature gradient and trapped electron modes has been improved to include the effects of parallel ion motion, finite beta, and collisionality. The model also includes the effects of impurities, fast ions, unequal ion and electron temperatures, and finite Larmor radius. This new model has been implemented in our time-dependent transport code and is used in conjunction with pressure-driven modes and neoclassical theory to predict the radial particle and thermal transport in tokamak plasmas. Simulations of TFTR, DIII-D, and JET L-mode plasmas have been conducted to test how the new effects change the predicted density and temperature profiles. Comparisons are made with results obtained using the previous version of the model which was successful in reproducing experimental data from a wide variety of tokamak plasmas. Specifically, the older model has been benchmarked against over 50 discharges from at least 7 different tokamaks including L-mode scans in current, heating power, density, and dimensionless scans in normalized gyro-radius, collisionality, and beta. We have also investigated the non-diffusive elements included in the Weiland model, particularly the particle pinch in order to characterize its behavior. This is partly motivated by recent simulations of ITER. In those simulations, the older Weiland model predicted a particle pinch and ignition was more easily obtained.

  17. Modeling Apple Surface Temperature Dynamics Based on Weather Data

    Directory of Open Access Journals (Sweden)

    Lei Li

    2014-10-01

    Full Text Available The exposure of fruit surfaces to direct sunlight during the summer months can result in sunburn damage. Losses due to sunburn damage are a major economic problem when marketing fresh apples. The objective of this study was to develop and validate a model for simulating fruit surface temperature (FST dynamics based on energy balance and measured weather data. A series of weather data (air temperature, humidity, solar radiation, and wind speed was recorded for seven hours between 11:00–18:00 for two months at fifteen minute intervals. To validate the model, the FSTs of “Fuji” apples were monitored using an infrared camera in a natural orchard environment. The FST dynamics were measured using a series of thermal images. For the apples that were completely exposed to the sun, the RMSE of the model for estimating FST was less than 2.0 °C. A sensitivity analysis of the emissivity of the apple surface and the conductance of the fruit surface to water vapour showed that accurate estimations of the apple surface emissivity were important for the model. The validation results showed that the model was capable of accurately describing the thermal performances of apples under different solar radiation intensities. Thus, this model could be used to more accurately estimate the FST relative to estimates that only consider the air temperature. In addition, this model provides useful information for sunburn protection management.

  18. Can spatial statistical river temperature models be transferred between catchments?

    Science.gov (United States)

    Jackson, Faye L.; Fryer, Robert J.; Hannah, David M.; Malcolm, Iain A.

    2017-09-01

    There has been increasing use of spatial statistical models to understand and predict river temperature (Tw) from landscape covariates. However, it is not financially or logistically feasible to monitor all rivers and the transferability of such models has not been explored. This paper uses Tw data from four river catchments collected in August 2015 to assess how well spatial regression models predict the maximum 7-day rolling mean of daily maximum Tw (Twmax) within and between catchments. Models were fitted for each catchment separately using (1) landscape covariates only (LS models) and (2) landscape covariates and an air temperature (Ta) metric (LS_Ta models). All the LS models included upstream catchment area and three included a river network smoother (RNS) that accounted for unexplained spatial structure. The LS models transferred reasonably to other catchments, at least when predicting relative levels of Twmax. However, the predictions were biased when mean Twmax differed between catchments. The RNS was needed to characterise and predict finer-scale spatially correlated variation. Because the RNS was unique to each catchment and thus non-transferable, predictions were better within catchments than between catchments. A single model fitted to all catchments found no interactions between the landscape covariates and catchment, suggesting that the landscape relationships were transferable. The LS_Ta models transferred less well, with particularly poor performance when the relationship with the Ta metric was physically implausible or required extrapolation outside the range of the data. A single model fitted to all catchments found catchment-specific relationships between Twmax and the Ta metric, indicating that the Ta metric was not transferable. These findings improve our understanding of the transferability of spatial statistical river temperature models and provide a foundation for developing new approaches for predicting Tw at unmonitored locations across

  19. Water source heat pumps for greenhouse soil cooling. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Spieser, H.

    1987-06-01

    In an attempt to diversify and grow flowers which are in high demand, growers are looking to produce certain exotic flowers which require unique growing conditions. One example is the Alstroemerias also knwon as the Peruvian Lily. If the plants are grown continuously at about 12-15/sup 0/C soil temperature, the plant will continue to flower regardless of air temperature and photoriod. These latter two factors are considered secondary to the importance of cool soil temperatures. Alstroemeria production is still relatively new to the greenhouse industry. Some controversy still exists as to the direct benefits of planned soil cooling. This project was set up to evaluate a mechanical soil cooling system for continuous year round Alstroemeria production. A heat pump soil cooling system was installed in two greenhouses each with dimensions of 16 m by 61 m. Combined these greenhouses have a growing area of 1952 m/sup 2/. These greenhouses are older wooden greenhouses, covered by double poly, air-inflated glazing. This system worked very well, maintaining the soil temperature at the proper levels throughout the spring and summer months. During the rest of the year the soil cooling system is used less intensely. During winter months when soil cooling is not required, the heat pumps provide base load heating to the greenhouse through fan forced unit heaters.

  20. Modelling Brain Temperature and Perfusion for Cerebral Cooling

    Science.gov (United States)

    Blowers, Stephen; Valluri, Prashant; Marshall, Ian; Andrews, Peter; Harris, Bridget; Thrippleton, Michael

    2015-11-01

    Brain temperature relies heavily on two aspects: i) blood perfusion and porous heat transport through tissue and ii) blood flow and heat transfer through embedded arterial and venous vasculature. Moreover brain temperature cannot be measured directly unless highly invasive surgical procedures are used. A 3D two-phase fluid-porous model for mapping flow and temperature in brain is presented with arterial and venous vessels extracted from MRI scans. Heat generation through metabolism is also included. The model is robust and reveals flow and temperature maps in unprecedented 3D detail. However, the Karmen-Kozeny parameters of the porous (tissue) phase need to be optimised for expected perfusion profiles. In order to optimise the K-K parameters a reduced order two-phase model is developed where 1D vessels are created with a tree generation algorithm embedded inside a 3D porous domain. Results reveal that blood perfusion is a strong function of the porosity distribution in the tissue. We present a qualitative comparison between the simulated perfusion maps and those obtained clinically. We also present results studying the effect of scalp cooling on core brain temperature and preliminary results agree with those observed clinically.

  1. Can sigma models describe finite temperature chiral transitions?

    CERN Document Server

    Kocic, Aleksandar; Aleksandar KOCIC; John KOGUT

    1995-01-01

    Large-N expansions and computer simulations indicate that the universality class of the finite temperature chiral symmetry restoration transition in the 3D Gross-Neveu model is mean field theory. This is a counterexample to the standard 'sigma model' scenario which predicts the 2D Ising model universality class. We trace the breakdown of the standard scenario (dimensional reduction and universality) to the absence of canonical scalar fields in the model. We point out that our results could be generic for theories with dynamical symmetry breaking, such as Quantum Chromodynamics.

  2. Biases in greenhouse gases static chambers measurements in stabilization ponds: Comparison of flux estimation using linear and non-linear models

    Science.gov (United States)

    Silva, Juan P.; Lasso, Ana; Lubberding, Henk J.; Peña, Miguel R.; Gijzen, Hubert J.

    2015-05-01

    The closed static chamber technique is widely used to quantify greenhouse gases (GHG) i.e. CH4, CO2 and N2O from aquatic and wastewater treatment systems. However, chamber-measured fluxes over air-water interfaces appear to be subject to considerable uncertainty, depending on the chamber design, lack of air mixing in the chamber, concentration gradient changes during the deployment, and irregular eruptions of gas accumulated in the sediment. In this study, the closed static chamber technique was tested in an anaerobic pond operating under tropical conditions. The closed static chambers were found to be reliable to measure GHG, but an intrinsic limitation of using closed static chambers is that not all the data for gas concentrations measured within a chamber headspace can be used to estimate the flux due to gradient concentration curves with non-plausible and physical explanations. Based on the total data set, the percentage of curves accepted was 93.6, 87.2, and 73% for CH4, CO2 and N2O, respectively. The statistical analyses demonstrated that only considering linear regression