Vernal Equinox Research Articles

On equatorial spread F occurrence: A multi-dimensional quantitative assessment

The present study investigates the role of gravity wave induced seed perturbations in the occurrence of Equatorial Spread F (ESF) under the influence of the post sunset background conditions modulated by prevailing electrodynamics and neutral wind. Ionospheric foF2 data sets over geomagnetic equatorial station Trivandrum (8.5°N, 77°E and magnetic dip 0.68°N-corresponding to the period of study) corresponding to vernal and autumnal equinoctial periods encompassing high, low and moderate solar activity years, are used for the study. Meridional wind data is obtained either from ESA’s sun-synchronous satellite GOCE (Gravity field and steady-state Ocean Circulation Explorer) or derived using ionosonde h’F (base height of ionosphere at 2.5 MHz) data from Trivandrum (TVM- 8.5°N, 77°E and magnetic dip 0.68°N) and Sriharikota (SHAR−13.7°N, 80.2°E and magnetic dip 6.9°N-for period of study). This particular study is carried out for geomagnetically quiet days of Vernal Equinox (VE) and Autumnal Equinox (AE) seasons, which are most favoured for ESF occurrence over Indian longitudes. Considering thermospheric wind, ion-neutral collisions, and electric field effects in association with gravity wave seed, threshold curve is generated, which clearly demarcates ESF and NSF (Non spread F) days. Previous studies have addressed ESF variability in electrodynamical domain alone (wherein the layer is above a threshold level). The present study, for the first time, succeeds in demarcating ESF and NSF days by incorporating effects of electric field, neutral wind, collisional RT instability term, and gravity wave seed perturbations simultaneously irrespective of threshold height.

Occurrence characteristics of ionospheric scintillations in the civilian GPS signals (L1, L2, and L5) through a dedicated scintillation monitoring receiver at a low-latitude location in India during the 25th solar cycle

Abstract The ionospheric post-sunset irregularities are responsible for the discrepancies in the received global navigation satellite system (GNSS) signals to fluctuate the phase and amplitude resulting in scintillations in the respective components. Ionospheric scintillations reduce the signal quality and alter the signal reception time inducing position errors which is not preferable for the precise position applications. The level of ionospheric amplitude scintillation, quantified by the amplitude scintillation index (S4), is analyzed during the year 2022, which accentuates the ascending phase of solar cycle 25. For this, we analyzed scintillation intensity and occurrence percentage at a low latitude Indian location in India by employing all the available frequencies of the global positioning system (GPS) constellation. The scintillation distribution for each month is also observed which reveals that the autumn equinox seasons has high scintillation occurrence compared to the vernal equinox seasons. The impact of the scintillation on the three civilian signals (L1, L2 and L5) of the GPS constellation is also observed in terms of the scintillation intensity distribution. The cross-correlation of the S4 index for these three signals reveals a strong correlation existing among them during strong scintillations whereas L2 and L5 signals portray a high correlation irrespective of signal intensities. In brief, the strong scintillation occurrence percentage is higher in the L5 signal compared to the L1 and L2 in contrast with weak scintillation, which is high in L1, followed by L2 and L5. Further, the analysis shows that the autumnal equinox has the highest percentage occurrence of strong scintillations (less than 10 % of the scintillation cases) compared to the vernal equinox whereas among solstice seasons June solstice presented the least scintillation occurrence at the location. The outcomes of this study instigate further analysis of scintillation occurrences from diverse GNSS frequencies covering diverse solar activity conditions for complementing the development of robust scintillation mitigation strategies across the low latitudes during the diverse scintillation conditions.

МИФОЭПИЧЕСКИЕ ОСНОВЫ АДЫГСКОГО НОВОГО ГОДА

The article considers the traditional spring holiday “Alternation of heads of years” (Ilesyshye zablek1ygu) on March 21–23 among the Adygs (Circassians) people, dedicated to Shyuzeresh the patron saint of abundance and horsemen. The aim of the work is to study the mythoepic basis of the traditional holidays associated with the spring and winter solstices. Based on this goal, the tasks of identifying representations of sacred processes designed to create favorable conditions for the preparation and start of spring field work and seasonal agricultural completion of the year are solved. The relevance of the research topic is due to the insufficient knowledge of the calendar holidays of the Adygs, in this case, associated with the vernal equinox and winter solstice. The theoretical basis of the mythological rituals requires in-depth study, since the process of reanimation of folk festivals is one of the important components of the self-identification of the Adyghe. Travel essays by missionaries, the research activities of the Adyghe enlighteners of the 19th century Sultan Khan Giray, Shora Nogmov, Adil Giray Keshev, folklorists Askarbiy Shortanov, Mukhtar Meretukov, Adam Gutov, Aslan Tsipinov and other scholars served as the methodological basis of this work and determined the basic principles of research: the comparative-historical, historical-typological, and comparative analyses. The novelty of the study lies in the fact that it describes for the first time the rituals of the spring festival, symbolizing the onset of the Adyghe New Year, and the time of spring plowing, which began on the third day after the onset of the holiday “Alternating heads of Years”, as well as the winter solstice holiday. The result of the study was the conclusion that the worldview and worldview of the ancient Adyghe was at a high level for its time and evolved along with the process of progressive development of the Adyghe society. It is established that a historical and cultural excursion into the past about the existence of the New Year among the Adyghe (Circassians) and the winter solstice holiday makes it possible to know the depth of the processes of the mythoepic consciousness of the people. The theoretical and practical value of the work is seen in the possibility of using the results of the research in theoretical disciplines and practical research on folklore, epic studies, the study of the mythoepical basis of the Adyghe worldview, as well as in the educational process of educational institutions.

Development of the Generation 3 Particle Pilot Plant Falling Particle Receiver

A falling particle receiver (FPR) has been designed to integrate with the G3P3-USA pilot plant currently being constructed at the National Solar Thermal Test Facility (NSTTF) at Sandia National Laboratories. This receiver integrates several innovative design features including a converging tunnel (SNOUT), an optimized cavity geometry, and a multistage “catch-and-release” trough. Details about the integration of these features and the final G3P3-USA FPR design and construction are described. Ray-tracing models of the FPR utilizing the NSTTF heliostat field are developed leveraging previous modeling efforts using SolTrace. Models demonstrate that at least 1.5 MWth of incident radiative energy can be provided to the FPR on a clear day throughout a typical year in Albuquerque, NM. Spillage fluxes around the periphery of the aperture are within acceptable bounds for the majority of the year. Intercept factors are computed for each utilized heliostat at the Vernal equinox to provide guidance to heliostat operators during operation of the system.

Taking Titan’s Boreal Pole Temperature: Evidence for Evaporative Cooling in Ligeia Mare

From 2004 to 2017, the Cassini RADAR recorded the 2.2 cm thermal emission from Titan’s surface in its passive (radiometry) mode of operation. We use this data set to investigate the seasonal evolution of the effective temperature sensed by the microwave radiometer in two regions in the northern pole of the satellite: the sea Ligeia Mare, and its nearby solid terrains. We find that despite the arrival of summer at the end of the mission, the effective temperature of Ligeia Mare decreased by almost 1 K, while that of the solid region slowly increased until 2017 by 1.4 ± 0.3 K. These observations, as well as the lag in summer warming observed by Cassini’s Composite Infrared Spectrometer, can be explained by evaporative cooling in both the solid and liquid surfaces after the vernal equinox. It therefore supports the idea that the northern polar terrains are wet. Using an ocean circulation model, we show that the cooling of the sea surface should initiate convection in the sea’s interior, ultimately cooling the whole liquid column sensed by the Cassini radiometer and thus decreasing the temperature at depths even long after the evaporation period has ceased. Overall, this work highlights the key role of methane hydrology in controlling the surface and submarine temperatures in the boreal polar regions of Titan.

Off-design performance evaluation of thermally integrated pumped thermal electricity storage systems with solar energy

Pumped thermal electricity storage that integrates with low-grade heat source (thermally integrated PTES, TI-PTES) have gained widespread attention due to the superior performance compared to traditional PTES systems. In this work, a TI-PTES system integrated with solar energy is constructed. R1233zd(E) is employed as the working fluid in the system. Select solar data from four typical days (Vernal Equinox, Summer Solstice, Autumn Equinox, Winter Solstice) throughout the year in Chuxiong City, Yunnan Province, which has abundant solar resources. Design conditions for the system are determined by a multi-objective optimization approach, and based on this, the off-design performance of both the charge and discharge processes are studied. The off-design models for the main components of the system are established. In the charge process, the weather conditions from 10:00 to 15:00 on a typical day are selected for a 6-hour charge period, and a parameter analysis of the system is conducted under different weather conditions. In the discharge process, the off-design performance of the system under different load levels is analyzed for two operating modes: constant pressure mode and variable pressure mode. The results indicate that in the charge process, the values of the compressor power under off-design conditions (Wcomp,off), the mass flow rates of the heat pump system (mRHP), and thermal energy storage system (mts) of Winter Solstice are the highest from 11:00 to 15:00 compared to the other 3 days. In the discharge process, the power-to-power efficiency (ηPTP) and Levelized Cost of Storage (LCOS) of the Vernal Equinox and Autumn Equinox reach their maximum (74.47 %) and minimum (0.247 $·kWh−1) values at an 80 % load level under variable pressure mode. Under constant pressure mode, the power-to-power efficiency and LCOS of the Vernal Equinox and Autumn Equinox reach their maximum (74.34 %) and minimum (0.232 $·kWh−1) values at 70 % and 40 % load levels. Comparing the off-design performance between the variable pressure mode and constant pressure mode in the discharge process, the variable pressure operation mode is recommended for load levels between 78 % and 85 %, while the constant pressure operation mode is recommended for load levels between 40 % and 78 %, as well as between 85 % and 120 %. The obtained results can serve as a reference for the off-design performance analysis of TI-PTES.

The performance evaluation of the free-falling particle solar receiver with a novel zigzag mass-flow controlled particle release pattern

A free-falling particle receiver is a promising technology to be used in concentrating solar power plants. In this study, an optical-thermal coupled model is established by combining a Monte Carlo ray-tracing method with a finite volume method to simulate the energy transfer processes in a solar power tower system employing a cavity receiver. Using the developed model, a novel particle release pattern, zigzag mass-flow controlled pattern, is proposed and compared with three other patterns, straight-line, zigzag, and mass-flow controlled patterns. First, the effects of the amplitude of the zigzag particle release slots on the receiver performance are analyzed. Then, the variations of the solar energy entering the receiver at different times on the vernal equinox is studied. Moreover, a new particle release pattern, zigzag mass-flow controlled pattern, is proposed and evaluated. The results demonstrated that the thermal performance of the zigzag mass-flow controlled particle release pattern was found to be superior to the other three patterns, allowing an increase in the thermal efficiency of 2.90 %. This allows for achieving effective thermal performance improvements while employing cost-effective designs in the free-falling particle receiver.

The Correlation between Ionospheric Electron Density Variations Derived from Swarm Satellite Observations and Seismic Activity at the Australian–Pacific Tectonic Plate Boundary

Swarm electron density (Ne) observations from the Langmuir probe (LP) can detect ionospheric disturbances at the altitude of a satellite. Along-track satellite observations provide a large number of very short observations of different places in the ionosphere, where Ne is disturbed. Moreover, different perturbations occupy various Ne signal frequencies. Therefore, such short signals are more recognizable in two dimensions, where aside from their change in time, we can observe their diversity in the frequency domain. Spectral analysis is an essential tool applied here, as it enables signal decomposition and the recognition of composite patterns of Ne disturbances that occupy different frequencies. This study shows a high-resolution application of short-term Fourier transform (STFT) to Swarm Ne observations in the Papua New Guinea region in the vicinity of earthquakes, tsunamis, and related general seismic activity. The system of tectonic plate junctions, including the Pacific–Australian boundary, is located orthogonally to Swarm track footprints. The selected wavelengths of seismically induced ionospheric disturbances detected via Swarm are compared with the three sets of three-month records of seismic activity: in the winter solstice of 2016/2017, when seismic activity was highest, and in the summer solstice and vernal equinox of 2016, which were calmer. Moreover, more Swarm data records are analyzed at the same latitudes for validation purposes, in a place where there are no tectonic plate boundaries that are orthogonal to the Swarm orbital footprint. Additional validation is supplied through Swarm Ne observations from completely different latitudes, where the Swarm orbital footprint orthogonally crosses a different subducting plate boundary. Aside from the seismic energy, the solar radio flux (F10.7), equatorial plasma bubbles (EPBs), and geomagnetic ap and Dst indices are also reviewed here. Their influence on the ionospheric Ne is also found in Swarm observations. Finally, the Pearson correlation coefficient (PCC), applied to the pairs of 3-month time series created from Swarm Ne variations, seismic energy, ap, Dst, and F10.7, summarizes the graphical inspection of mutual correlations. It points to the predominant correlation of Swarm Ne disturbances with seismicity, especially during nighttime. We show that most of the Ne disturbances at a selected wavelength of 300 km correlate more with seismicity than with geomagnetic and solar indices. Therefore, Swarm LP can be assessed as being capable of observing the lithosphere–atmosphere–ionosphere coupling (LAIC) from the orbit.

Study on the dynamic characteristics of a concentrated solar power plant with the supercritical CO2 Brayton cycle coupled with different thermal energy storage methods

The paper aims to study the impact of Thermal Energy Storage (TES) technology on the dynamic characteristics of Concentrated Solar Power (CSP). An integrated dynamic model of a CSP plant is firstly established, which combines the concentrating system, the TES system, and S–CO2 Brayton power cycle system. Three TES alternatives are considered: two-tank molten salt TES (TT-TES), packed-bed TES with solid fillers (PBS-TES), packed-bed TES with phase change materials (PBP-TES). Using this integrated dynamic model, the thermal performance and economic feasibility of different TES technologies applied to CSP are compared and analyzed. The results indicate that utilization of packed-bed TES primarily impacts the optical efficiency of the heliostat field and the thermal efficiency of the power cycle, while having minimal effect on the receiver's thermal efficiency. Furthermore, during the vernal equinox, the daily average system efficiencies of CSP configurations integrating TT-TES, PBS-TES, PBP-TES technologies are 26.0 %, 25.5 %, and 24.5 %, respectively. Meanwhile, the use of packed-bed TES systems significantly reduces the material cost of the TES. In comparison to the TT-TES, the PBP-TES and the PBS-TES can reduce cost by 21.2 % and 42.3 %, respectively, and decrease TES volume by 83.0 % and 63.8 %, respectively.

Genetic algorithm optimization of heliostat field layout for the design of a central receiver solar thermal power plant

The heliostat field layout in a central receiver solar thermal power plant has significant optical losses that can ultimately affect the overall output power of the plant. In this paper, an optimized heliostat field layout based on annual efficiency and power of 50 MW for the local coordinates of Quetta, Pakistan, is proposed. The performance of two different heliostat field layouts such as radial staggered and Fermat's spiral distribution are evaluated and different design points in a year are considered for the analysis. The field layouts are then optimized using a rejection sampling based Genetic Algorithm (GA). It considers the output power and mean overall efficiency for vernal equinox, summer solstice, autumnal equinox, and winter solstice as objective functions. The GA optimizes the heliostat field parameters, namely, security distance (DS), tower height (TH), heliostat width to length ratio (WR), and the length of heliostats (LH). The study system was developed in MATLAB for validation. It was observed that for the radial staggered layout, the number of heliostats decreased by 364 and the efficiency was improved by 8.52 % using GA optimization relative to unoptimized results field layout. The annual efficiency for Fermat's spiral configuration was improved by 14.62 % and correspondingly, the number of heliostats decreased by 434.

Seasonal resting metabolic rate in Platorchestia platensis (Amphipoda, Talitridae)

Abstract Populations of Platorchestia platensis were collected throughout the annual season at Indian Point (N.B., Canada), then acclimated (wrack or driftwood) and oxygen uptake measurements were made on individuals at standard temperature (approx. 19°C) and lighting conditions (1212-hour lightdark). P. platensis reduces resting rate (= standard metabolic rate, SMR) and growth and reproduction cease (diapause) during the colder months. SMR and growth begin increasing when the warm season starts towards the end of March at Indian Point. Wrack-acclimated P. platensis SMR peaks near the summer solstice in June and a month later for driftwood-acclimated populations. The SMR of wrack-acclimated P. platensis at 45°N begins dropping, following the June peak, towards a period of overwintering dormancy (= diapause) to be reached near the vernal equinox in September. Wrack-acclimated populations of P. platensis in winter maintain their inverse metabolic relationship with size. During winter in driftwood-acclimated populations, the relationship with weight is lost.

Experimental investigations on a sustainable cogeneration system for power and desalination with 4-E analysis

Several research investigations were carried out on the potential integration of solar stills with photovoltaic modules to improve freshwater production and electric output. The current work aims at integrating stepped solar still (SSS) with a bi-directional flow serpentine thermal absorber-based Photovoltaic-Thermal (PVT) module. Near the vernal equinox days, a laboratory-scale experimental facility is designed, developed, and tested in Vellore (12.9165° N, 79.1325° E). The novelty of the proposed system is that it effectively utilizes the waste heat recovered from PVT with a unique thermal absorber for preheating saline water supplied to the SSS. Experiments were carried out on a PVT-SSS system to estimate the electricity and freshwater generation by PVT and SSS for saline water flowrates of 0.3, 0.5, 0.75, and 1.00 LPM. The estimated average electrical efficiency of the PVT panel is 14.84 %, 15.46 %, 14.74 %, and 14.50 %, and the freshwater productivity from SSS is 3460 ml, 2970 ml, 2460 ml, and 1950 ml per square meter. The average thermal efficiency of the proposed PVT-SSS system is 34.5 %, 31.8 %, 20.1 %, and 16.3 %; 49.36 %, 47.30 %, 34.90 %, and 30.83 %, respectively, for the mentioned flow rates. Further, the average exergy efficiency of the system is observed as 18.5 %, 18.7 %, 17.2 %, and 16.6 %, respectively. In addition, the unit cost of freshwater production for various flow rates in USD is estimated as 0.07, 0.08, 0.09, and 0.10, respectively. An environmental analysis was also performed to determine the CO2 emissions and carbon mitigation for the proposed hybrid desalination system. The results are validated with previous literature.

A lesson plan revisiting the Eratosthenes experiment to teach the seasons inductively from a space-based perspective

This paper presents a lesson plan designed to teach seventh-grade students about the seasons and reflections of the students using an inductive approach from a space-based perspective. The plan establishes students’ prior knowledge of the topic and continues with the Eratosthenes experiment as a central experience. Eratosthenes experimented in the 250s BC and calculated the Earth’s circumference during the summer solstice in the Northern Hemisphere. Teachers used this experiment as a practical learning tool to teach the concept of seasons using the inductive method. Eleven seventh-grade students from Turkey, thirty middle-grade students from Indonesia, and their science teachers participated in the study. The students conducted the Eratosthenes experiment in vernal equinox in Turkey and Indonesia and calculated the circumference of the Earth. The measurements were taken in the experiment from a space-based perspective. After conducting the Eratosthenes experiment, the students reflected on their experiences. They discussed the connection of the experiment to the causes of the seasons. Afterwards, teachers conducted direct instruction and problem-solving activities related to the seasons. Reflections from student experiences and experiments were discussed. The study concluded that the lesson plan involving the Eratosthenes experiment provides an in-depth experience for students and enhances their understanding of the factors related to the space-based perspective.

Arctic climate warming: discrepancies between global climate
 models and observations and possible causes

Global climate models are used to predict anthropogenic climate change and to plan social and economic activities under changing climatic conditions. At the same time, there are discrepancies between model projections and observed climate changes, especially in low latitudes and polar regions. One reason for the discrepancy may be insufficient attention to natural forcings on the climate system. Therefore, studies of the role of natural factors in the development of modern warming are relevant for
 improving the reliability of forecasts for the development of the climatic situation on Earth. Particular attention is paid to the impact of climate change in low latitudes on the Arctic. A significant contribution to these changes can be made by a long-term increase in low-latitude insolation. Most of the low latitudes
 are occupied by the ocean, which absorbs the bulk of the incoming solar radiation. The contribution of the increase in insolation to the increase in ocean surface temperature at low latitudes is estimated from the available data on insolation of the upper boundary of the atmosphere. The changes in SST at low latitudes are compared according to reanalysis data and calculations of global climate models. Comparison of climate changes in low latitudes and in the Arctic is made. The influence from low latitudes on the reduction in the area of sea ice and the increase in water temperature in the Arctic basin is estimated. Changes in the characteristics of the atmosphere and ocean at low latitudes, associated with an increase in insolation, after
 3 years are manifested in changes in the characteristics of the climate and sea ice in the Arctic. This indicates the potential for improved global modeling of warming in the Arctic and at low latitudes when taking into account slow changes in radiative forcing at the upper boundary of the atmosphere due to the Earth’s orbital dynamics. Insolation trends at low latitudes are maximum in spring, i.e., in the vicinity of the vernal equinox in the Earth’s orbit. This indicates the influence of precession — a slow shift of the equinox point, when the influx of solar radiation to low latitudes is maximum, to the perihelion, where it will be 3 W/m2more.

Multi‐Wavelength (L and S Band) Study of Ionospheric Irregularities From an Anomaly Crest Location

AbstractThis paper reports observation of moderate to intense scintillations, at S band of Indian Regional Navigation Satellite System (IRNSS). During current solar cycle 25, these occurrences are probably being reported for the first time, from a low‐latitude station Calcutta (22.58°N, 88.38°E geographic; magnetic dip 34.54°), located near the northern crest of Equatorial Ionization Anomaly. Efforts have been made to analyze irregularity dynamics at IRNSS S band, along with a comparative study at GNSS L1 to characterize occurrence and evolution of multiscale irregularity structures. Power spectral analysis technique has been applied on recorded C/NO, during scintillation patches, to measure east‐west zonal drift velocity. Efforts are also made to study intensity of signal perturbation at L5 frequency of IRNSS, compared to S band, when observed simultaneously, during period of ionospheric scintillation. Concurrent irregularity dynamics at L1, L5, and S band, particularly from a low‐latitude station, has not been extensively reported earlier. Data is recorded during vernal equinox (February–April 2022) of current solar cycle. Results of this study show occurrence of simultaneous night‐time scintillation at L1, L5, and S band. East‐west zonal drift velocity of irregularity, obtained from S band observations are found to decrease with the progress of time during 20–23 LT having a maximum value of 125 m/s. At GNSS L1, hourly average value of the velocity, is observed to maximize during 20–21 LT. Simultaneous observation of scintillation effects at L5 and S band of IRNSS led to loss‐of‐lock at L5, while no such occurrence was noted at S band.

Date Of Easter Sebagai Reformasi Kalender Masehi

This research discusses the history of the calculation of the date of Easter as part of the reform of the Gregorian calendar using a historical approach. It examines the history of the determination of the date of Easter by the Council of Nicaea in 325 AD and the use of the ecclesiastical full moon method to calculate the date of Easter. This research also discusses the differences in the dating of Easter in the Julian and Gregorian calendars and the relationship between the dating of Easter and the astronomical vernal equinox. The results of this research show that the date of Easter is calculated based on mathematical calculations, taking into account the ecclesiastical full moon and is no longer related to accurate astronomical calculations. This research provides a clear overview of the history and methods of determining the date of Easter and can serve as a reference for scientists and researchers to further study the reform of the Gregorian calendar and the calculation of the date of Easter.

Eccentricity and orientation of Earth's orbit from equinox and solstice times

A straightforward method of determining the eccentricity of Earth's orbit and the position of aphelion and perihelion relative to the vernal equinox from solstice and equinox times is described. The only assumption made is that the orbital eccentricity is small. Using dates for these phenomena adopted from a desk calendar gives the eccentricity to an accuracy of about 10%.

Whence the 8th Day of the 4th Lunar Month as the Buddha’s Birthday

Two dates, the 8th day of the 4th lunar month (Date A) and the 8th day of the 2nd lunar month (Date B), are found in Chinese Buddhist translations as the Buddha’s birthday. However, how to understand the simultaneous existence of both of these dates remains an unresolved problem. This paper proposes a rather new interpretation to try to solve this puzzle, and provide an answer to the question: whence the 8th day of the 4th lunar month as the Buddha’s birthday? It is argued that: (1) The date of the Buddha’s conception and the date of his birth were both translated variously as Date A or Date B in early Chinese Buddhist literature. However, many later texts referring to the Buddha’s birthday do not include reference to an auspicious junction star (puṣyanakṣatra), which is critical for understanding these dates; (2) Both the Indian and Chinese traditions regard an individual’s life to begin at the moment of conception; therefore, the so-called Buddha’s birthday could be argued as the date of his conception; (3) The date of conception of the Buddha was specified as the 8th day of the śuklapakṣa of the month Vaiśākha, the day of the vernal equinox. This corresponds to Date A in the Chinese Xia calendar.

MODELING OF SPATIAL-TEMPORAL VARIATIONS OF DYNAMIC AND THERMAL PROCESS PARAMETERS IN GEOSPACE OVER UKRAINE DURING THE MINIMUM OF 24-TH CYCLE OF SOLAR ACTIVITY (2009, 2019)

We have performed the modelling of spatiotemporal variations of parameters of dynamic and thermal processes in ionospheric plasma at the phases of the minimum of the 24-th cycle of solar activity according to the Kharkiv radar of incoherent scattering. The diurnal dependences of parameters of the processes in the ionospheric plasma at altitudes from 210 to 450 km are constructed for typical geophysical periods (vernal and autumn equinoxes, summer and winter solstices). In the paper, the analysis of spatial and temporal variations of parameters of dynamic and thermal processes in the ionosphere is presented. We determined the value of the plasma transfer velocity due to ambipolar diffusion, the density of the full plasma flux, and the flux of charged particles due to ambipolar diffusion, the value of the energy supplied to the electron gas, the density of the heat flux transferred by electrons from the plasmasphere to the ionosphere, as well as the velocity of the equivalent neutral wind, and the meridional component of the neutral wind velocity. We found that weak variations in space weather do not lead to significant changes in spatiotemporal variations of the parameters of dynamic and thermal processes in the ionosphere for most of the studied periods. Quantitative and qualitative characteristics of most of these parameters and their diurnal variations were typical for the considered seasons. On the contrary, the velocity of the equivalent neutral wind changed significantly (up to 2—2.5 times) even with a weak increase in geomagnetic activity. The reasons for such changes may be the strengthening of horizontal thermospheric winds and the penetration of zonal magnetospheric electric fields into midlatitudes during the equinoxes. The obtained results of calculations can be used in basic studies of solar-terrestrial relations and geospace, for the solution of applied problems related to the ability to predict the state of space weather, as well as for further development of the regional ionosphere model CERIM IION. The object of research: physical processes in the ionospheric plasma. The subject of research: spatiotemporal dependences of the main parameters of ionospheric plasma, which were obtained using incoherent scattering radar. Research methods — terrestrial radiophysical method of incoherent scatter of radio waves, statistical analysis of observation results, semi-empirical modelling of parameters of dynamic and thermal processes.

Calculation of Volume of Hot Water Storage Tank in Air Source Heat Pump System

Air source heat pump integrated with hot water storage tank may enhance the efficiency of heating, and the volume of hot water storage tank is closely related to the thermal efficiency of the hot water system. Referring to the relevant formulas of building water supply and drainage design standards, this paper simulates the operation conditions of heat pump, and combined with the measured annual data of hot water using in a hospital, systematically discusses the adaptability of heat pump water production and seasonal hot water usage, as well as the actual regulating volume of hot water storage tank. Assumed the heat pump is altered by the working condition of the vernal equinox, the daily storage and discharge of the hot water tank can be accurately calculated, the hot water tank should charge 2.94 times of average hourly water yield of air pump during the peak water usage period. considering the safety and economy of the air source heat pump system, it is strongly recommended that the volume of hot water storage tank can be designed as the 5 ~ 6 times of hourly average water yield of air source heat pump, which can meet the usage of hot water for most of the time and it is inspected under various accidental conditions.