Modelling the influence of meteoric smoke particles on artificial heating in the D-region

We investigate if the presence of meteoric smoke particles (MSPs) influences the electron temperature during artificial heating in the D-region. By transferring the energy of powerful high-frequency radio waves into thermal energy of electrons, artificial heating increases the electron temperature. Artificial heating depends on the height variation of electron density. The presence of MSPs can influence the electron density through charging of MSPs by electrons, which can reduce the number of free electrons and even result in height regions with strongly reduced electron density, so-called electron bite-outs. We simulate the influence of the artificial heating by calculating the intensity of the upward-propagating radio wave. The electron temperature at each height is derived from the balance of radio wave absorption and cooling through elastic and inelastic collisions with neutral species. The influence of MSPs is investigated by including results from a one-dimensional height-dependent ionospheric model that includes electrons, positively and negatively charged ions, neutral MSPs, singly positively and singly negatively charged MSPs, and photochemistry such as photoionization and photodetachment. We apply typical ionospheric conditions and find that MSPs can influence both the magnitude and the height profile of the heated electron temperature above 80 km; however, this depends on ionospheric conditions. During night, the presence of MSPs leads to more efficient heating and thus a higher electron temperature above altitudes of 80 km. We found differences of up to 1000 K in electron temperature for calculations with and without MSPs. When MSPs are present, the heated electron temperature decreases more slowly. The presence of MSPs does not much affect the heating below 80 km for night conditions. For day conditions, the difference between the heated electron temperature with MSPs and without MSPs is less than 25 K. We also investigate model runs using MSP number density profiles for autumn, summer and winter. The night-time electron temperature is expected to be 280 K hotter in autumn than during winter conditions, while the sunlit D-region is 8 K cooler for autumn MSP conditions than for the summer case, depending on altitude. Finally, an investigation of the electron attachment efficiency to MSPs shows a significant impact on the amount of chargeable dust and consequently on the electron temperature.

Modelling of the influence of meteoric smoke particles on artificial heating in the D-region

We investigate if the presence of meteoric smoke particles (MSP) influences the electron temperature during artfical heating in the D-region. The presence of MSP can result in height regions with reduced electron density, so-called electron bite-outs, due to charging of MSP by electrons. Artificial heating depends on the height variation of electron density. By transferring the energy of powerful high frequency radio waves into thermal energy of electrons, artificial heating increases the electron temperature. We simulate the influence of the artificial heating by calculating the intensity of the upward propagating radio wave. The electron temperature at each height is derived from the balance of radio wave absorption and cooling through elastic and inelastic collisions with neutral species. The influence of MSP is investigated by including results from a one-dimensional height-dependent ionospheric model that includes electrons, positively and negatively charged ions, neutral MSP, singly positively and singly negatively charged MSP and photo chemistry such as photo ionization and photo detachment. We apply typical ionospheric conditions and find that MSP can influence both the magnitude and the height profile of the heated electron temperature above 80 km, however this depends on ionospheric conditions. During night, the presence of MSP leads to more efficient heating, and thus a higher electron temperature, above altitudes of 80 km. We found differences up to 1000 K in temperature for calculations with and without MSP. When MSP are present, the heated electron temperature decreases more slowly. The presence of MSP does not much affect the heating below 80 km for night conditions. For day conditions, the difference between the heated electron temperature with MSP and without MSP is less than 25 K.

Parameters of Physical and Physiological Quality in Seed Produced during High Season for Different Periods of Development

Objective: To evaluate the quality of the seeds of tomato fruits (Solanum lycopersicum Mill.) produced in high temperture (HT) during different phases of development. Design/Methodology/Approach: Seeds of the Moneymaker variety were planted in a ventilated greenhouse (control treatment, CT) with maximum mean temperature (MMT) of 31.5 °C. A second greenhouse with artificial heating (MMT of 36.5 ºC) was used for the HT treatments. When anthesis began from the fourth floral cluster, seven treatments were established: T1) fruits growing permanently in the CT; T2) fruits transferred to HT between five and 12 days after anthesis (daa); T3) fruits growing in HT from 12 to 24 daa; T4) 24-36 daa in HT; T5) 36-48 daa in HT; T6) 48-60 daa in HT; T7) from 60 daa to maturity in HT. Results: The weight of one thousand seeds (SW) had a positive correlation with the length of seed (R=0.83*), indicating that the increase in SW was primarily determined by an increase in length. The vigor of the seed was measured by the germination after accelerated ageing (GAA); thus, germination and vigor are positively correlated with seed respiration during germination (0.62* and 0.81*, respectively). Study Limitations/Implications: HT impacting on the second phase of seed development could decrease both the physical and the physiological quality of tomato seeds. Findings/Conclusions: The seeds produced by T7 had lower SW (2.99 g). T5 caused lower amount of seeds per fruit (120), germination (79.4 %) and GAA (39.5 %).

The influence of meteoric smoke particles on the artificial heating effect in the D-region

<p>Artificial heating increases the electron temperature by transferring the energy of powerful high frequency radio waves into thermal energy of electrons. Current models most likely overestimate the effect of artificial heating in the D-region compared to observations [1, 2]. We investigate if the presence of meteoric smoke particles can explain the discrepancy between observations and model. The ionospheric D-region varies in altitude range from about 50 km to 100 km. In the D-region, the electron density is low, the neutral density is relatively high and it is here that meteors ablate. The ablated meteoric material is believed to recondense to form meteoric smoke particles (MSP). The presence of MSP in the D-region can influence plasma densities through charging of dust by electrons and ions, depending on different ionospheric conditions. Charging of dust influence the electron density mainly through electron attachment to the dust, which results in height regions with less electron density. The heating effect varies with electron density height profile [3], since the reduction in radio wave energy is due to absorption by electrons. We study artificial heating of the D-region and consider MSP by using a one-dimensional ionospheric model [4], which also includes photochemistry. In the ionospheric model, we assume that artificial heating only influences the chemical reactions that depend on electron temperature. We model the electron temperature increase during artificial heating with an electron density calculated from the ionospheric model, where we will do the modelling with and without the MSP and compare day and night condition. Our results show a difference in electron temperature increase with the MSP compared to without the MSP and between day and night condition.</p><p>References:</p><ul><li>[1] Senior, A., M. T. Rietveld, M. J. Kosch and W. Singer (2010): «Diagnosing radio plasma heating in the polar summer mesosphere using cross modulation: Theory and observations». Journal of geophysical research, Vol. 115, A09318.</li> <li>[2] Kero, A., C.-F Enell, Th. Ulich, E. Turunen, M. T. Rietveld and F. H. Honary (2007): «Statistical signature of active D-region HF heating in IRIS riometer data from 1994-2004». Ann. Geophys., 25, 407-415.</li> <li>[3] Kassa, M., O. Havnes and E. Belova (2005): «The effect of electron bite-outs on artificial electron heating and the PMSE overshoot». Annales Geophysicae, 23, 3633-3643.</li> <li>[4] Baumann, C., M. Rapp, A. Kero and C.-F. Enell (2013): «Meteor smoke influence on the D-region charge balance –review of recent in situ measurements and one-dimensional model results». Ann. Geophys., 31, 2049-2062.</li> </ul>

CALCULATION METHOD OF CULTIVATION FACILITY COMBINED HEATING SYSTEM USING WINTER GREENHOUSE AS AN EXAMPL

Modern systems of artificial heating of cultivation structures on the example of winter greenhouses intended for year-round use require the development of sufficiently accurate and reliable methods of calculation. According to the calculations, a decentralized heating system of agricultural facilities, which includes only ceiling infrared heating elements, is justified only in a moderately cold period of the year. At lower outdoor temperatures, mainly in January, the indoor temperature may drop below standard values due to the specifics of radiant heating. Therefore, the article considers the method of calculating heat power of the radiant and convective heating system that includes infrared emitters for soil heating and convective heating devices for maintaining the target indoor air temperature. The calculation procedure of radiant and convective (combined) heating system comes to the calculation of incoming and outgoing heat and mass fluxes as well as finding unknown microclimate parameters (first of all, inside air temperature) that form design heat and humidity conditions of an agrobiotechnological facility. The proposed calculation method has been tested at the industrial greenhouse “Fermer 7.5”.

A parametric building energy simulation case study on the potential and limitations of passive design in the Mediterranean climate of Malta

The present case study sets out to investigate the potential and limitations of passive building design in a typical Mediterranean climate. The Maltese Islands were taken as the case study location. Assuming a fully detached, cuboid-shaped, generic multi-storey office building, one representative storey was modelled by means of the building energy simulation code WUFI®Plus. Thermal comfort was analysed based on the adaptive acceptable operative room temperature concept of EN 15251 for buildings without mechanical cooling systems. Assuming neither artificial heating nor cooling, the free-running operative room temperature was evaluated. By means of a parametric study, the robustness of the concept was analysed and the impact of orientation, window to wall area ratio, glazing, shading, thermal insulation, nighttime ventilation and thermal mass on the achievable level of thermal comfort is shown and discussed. It is concluded that in a well-designed building and by means of decent insulation (present case: Uwall = 0.54 W/(m2 · K)), double glazing, variable external shading devices and passive cooling by nighttime ventilation, a high level of thermal comfort is achievable in this climate using only very minor amounts of energy for artificial heating and cooling or possibly even none at all.

Technical universities students’ readiness for eco-oriented values development

The article discusses issues related to assessment of readiness of students of a technical College to form the foundations of ecological culture. Emphasized that the problems of modern society due to the long dominance of an anthropocentric attitude towards nature. Increasing anthropogenic pressures are often based on artificial heating of consumer demand. It is shown that the formation of eco-friendly values is impossible only through the educational process. The data of sociological survey of 183 students of the Samara state (133 boys and 50 girls) aged 17 to 22 years, who have not studied ecology. The impact of students on the environment assessed according to the method of the ecological footprint proposed by William Reese in 1992: in terms of consumption and way of life, only 16% of girls and 20% of boys fit into one planet. It is marked that a key moment in the formation of environmental culture is the choice of information sources. Revealed the following patterns of circulation the youth audience with information that the students prefer as information sources, television and online media, but trust more tutorials - 84% of girls and 70% boys; in the modern media for environmental information is presented in a minimal volume that shows the development potential of this mechanism of formation of ecological culture. Girls interested in the environmental, food safety, housing; tackling environmental issues at the level of educational institutions; environmental problems and their solutions in the region of residence. Men prioritize the following topics: activities of public ecological organizations and movements; scientific achievements in the field of ecology; global environmental issues. Only 50% of girls and 37% of boys consider themselves to be environmentally educated.