Small Increase In Temperature Research Articles

A heat transfer model for global warming

A heat transfer model for global warming was developed which included radiation transfer to the atmosphere and the earth. The model is based on the principles of heat transfer and well established engineering data and methods. Model results agree well with NASA data. From Hottel data, a method was developed for determining the emissivity of Carbon Dioxide and the emissivity of water vapor in the atmosphere as a function of concentration.The global warming conditions were determine for the Paris Limits, increases of 1.5° and 2 °C. The results show that Carbon Dioxide contributes 25% to the total temperature increase. Accounting for the reported accuracy in the emissivity of earth and the albedo, the most sensitivity solar parameters, the accuracy of the atmospheric temperature is outside the Paris Limits. The lease sensitivity solar parameter is the concentration of Carbon Dioxide. This is because at 300 ppm, the emissivity of CO2 is close to its maximum value. Carbon Dioxide is a major contributor to global temperature. However, since the emissivity of CO2 is close to its limit, additional increase in concentration will produce a small increase in atmospheric temperature.

The Influence of Thrust Chamber Structure Parameters on Regenerative Cooling Effect with Hydrogen Peroxide as Coolant in Liquid Rocket Engines

Liquid rocket engines with hydrogen peroxide and kerosene have the advantages of high density specific impulse, high reliability, and no ignition system. At present, the cooling problem of hydrogen peroxide engines, especially with regenerative cooling, has been little explored. In this study, a realizable k-epsilon turbulence model, discrete phase model, eddy dissipation concept model, and 10-step 10-component reaction mechanism of kerosene with oxygen are used. The increased rib height of the regenerative cooling channel causes the inner wall temperature of the engine increases, the average temperature of the coolant outlet decreases slightly, and the coolant pressure decreases. The overall wall temperature decreases as the rib width of the regenerative cooling channel increases. However, in the nozzle throat area, the wall temperature increases, the average coolant outlet temperature decreases, and the coolant pressure drop increases. A decrease in the inner wall thickness of the regenerative cooling channel results in a significant decrease in the wall temperature and a small increase in the average coolant outlet temperature. These findings contribute to the further development of the engine with hydrogen peroxide and can guide the design of its regenerative cooling process.

Assessment of Global Temperature Rise Based Upon Approved Algorithms

This Article presents the results of an independent assessment of the estimated global temperature increase since the 1.1degree Celsius measured in 2020. It illustrates that the goals of the 2015 Paris Climate Agreement can be met by the end of the century by gradually reducing Carbon Dioxide emissions from present levels. The required rate of global emissions reductions is significantly less than those estimated by the United Nations reports. Most of the difference in estimates can be attributed to an error that was made by the UN in figuring the future atmospheric concentration of Methane. All of the various agency reports forgot to account for the short 12-year lifetime of CH4 that must be subtracted from the total new yearly emissions to then yield very small net concentration and temperature increases. The Nations of the World will be jubilant to hear that they now have both more time and lower yearly emission reduction requirements than currently reported.

Effect of elevated embryonic incubation temperature on the temperature preference of juvenile lake (Coregonus clupeaformis) and round whitefish (Prosopium cylindraceum).

Anthropogenic impacts can lead to increased temperatures in freshwater environments through thermal effluent and climate change. Thermal preference of aquatic organisms can be modulated by abiotic and biotic factors including environmental temperature. Whether increased temperature during embryogenesis can lead to long-term alterations in thermal preference has not been explicitly tested in native freshwater species. Lake (Coregonus clupeaformis) and round (Prosopium cylindraceum) whitefish were incubated at natural and elevated temperatures until hatching, following which, all groups were moved to common garden conditions (15°C) during the post-hatching stage. Temperature preference was determined at 8months (Lake whitefish only) and 12months of age (both species) using a shuttle box system. Round whitefish preferred a cooler temperature when incubated at 2 and 6°C compared with 0.5°C. Lake whitefish had similar temperature preferences regardless of age, weight and incubation temperature. These results reveal that temperature preference in freshwater fish can be programmed during early development, and that round whitefish may be more sensitive to incubation temperature. This study highlights the effects that small increases in temperature caused by anthropogenic impacts may have on cold-adapted freshwater fish.

Elevated Winter Stream Temperatures below Wastewater Treatment Plants Shift Reproductive Development of Female Johnny Darter Etheostoma nigrum: A Field and Histologic Approach.

River water temperatures are increasing globally, particularly in urban systems. In winter, wastewater treatment plant (WWTP) effluent inputs are of particular concern because they increase water temperatures from near freezing to ~7-15 °C. Recent laboratory studies suggest that warm overwinter temperatures impact the reproductive timing of some fishes. To evaluate winter water temperature's influence in the wild, we sampled Johnny Darter Etheostoma nigrum from three urban South Platte River tributaries in Colorado upstream and downstream of WWTP effluent discharge sites. Fish were collected weekly during the spring spawning season of 2021 and reproductive development was determined from histological analysis of the gonads. Winter water temperatures were approximately 5-10 °C greater ~300 m downstream of the WWTP effluent compared to upstream sites, and approximately 3°C warmer at sampling sites ~5000 m downstream of the effluent discharge. Females collected downstream of WWTP effluent experienced accelerated reproductive development compared to upstream by 1-2 weeks. Water quality, including total estrogenicity, and spring water temperatures did not appear to explain varying reproductive development. It appears that small increases in winter water temperature influence the reproductive timing in E. nigrum. Further investigations into how shifts in reproductive timing influence other population dynamics are warranted.

Unprecedented fire activity above the Arctic Circle linked to rising temperatures.

Arctic fires can release large amounts of carbon from permafrost peatlands. Satellite observations reveal that fires burned ~4.7 million hectares in 2019 and 2020, accounting for 44% of the total burned area in the Siberian Arctic for the entire 1982-2020 period. The summer of 2020 was the warmest in four decades, with fires burning an unprecedentedly large area of carbon-rich soils. We show that factors of fire associated with temperature have increased in recent decades and identified a near-exponential relationship between these factors and annual burned area. Large fires in the Arctic are likely to recur with climatic warming before mid-century, because the temperature trend is reaching a threshold in which small increases in temperature are associated with exponential increases in the area burned.

Study of Drilled Holes after a Cryogenic Machining in Glass Fiber-Reinforced Composites

Glass fiber-reinforced composites are widely used in industry, with machining operations frequently performed, drilling, in particular, for later assembly. Although there is a smaller increase in temperature during drilling in composites than in metals, further cooling of the tool can produce improvements in some variables, such as thrust force, diameter, or surface roughness. This has been seen in studies where lower temperatures were achieved by cooling compressed air, reaching around −20 °C in plates of polyether-ether-ketone and polyamide, reinforced with glass fiber at 30% (PEEK-GF30 and PA-GF30, respectively). This paper analyzes the results of cryogenic drilling in plates of PEEK-GF30 and PA-GF30, specifically assessing thrust forces, diameter, and average surface roughness. The experimental methodology was carried out by monitoring thrust forces during cryogenic drilling using a piezoelectric dynamometer, measuring diameters with a coordinate measurement machine, and assessing surface quality with a roughness profilometer. During the cutting, the temperature of the cutting tool achieved a temperature near −120 °C from cooling with liquid nitrogen. Conducting an analytical and statistical study allowed us to determine the relationships between the measured variables and cutting conditions. Our results showed that cooling the tool during the drilling processes improved results of the cutting process.

Thermal effects on neurons during stimulation of the brain

All electric and magnetic stimulation of the brain deposits thermal energy in the brain. This occurs through either Joule heating of the conductors carrying current through electrodes and magnetic coils, or through dissipation of energy in the conductive brain. Objective. Although electrical interaction with brain tissue is inseparable from thermal effects when electrodes are used, magnetic induction enables us to separate Joule heating from induction effects by contrasting AC and DC driving of magnetic coils using the same energy deposition within the conductors. Since mammalian cortical neurons have no known sensitivity to static magnetic fields, and if there is no evidence of effect on spike timing to oscillating magnetic fields, we can presume that the induced electrical currents within the brain are below the molecular shot noise where any interaction with tissue is purely thermal. Approach. In this study, we examined a range of frequencies produced from micromagnetic coils operating below the molecular shot noise threshold for electrical interaction with single neurons. Main results. We found that small temperature increases and decreases of 1 ∘C caused consistent transient suppression and excitation of neurons during temperature change. Numerical modeling of the biophysics demonstrated that the Na-K pump, and to a lesser extent the Nernst potential, could account for these transient effects. Such effects are dependent upon compartmental ion fluxes and the rate of temperature change. Significance. A new bifurcation is described in the model dynamics that accounts for the transient suppression and excitation; in addition, we note the remarkable similarity of this bifurcation’s rate dependency with other thermal rate-dependent tipping points in planetary warming dynamics. These experimental and theoretical findings demonstrate that stimulation of the brain must take into account small thermal effects that are ubiquitously present in electrical and magnetic stimulation. More sophisticated models of electrical current interaction with neurons combined with thermal effects will lead to more accurate modulation of neuronal activity.

CO2 and CH4 exchanges between moist moss tundra and atmosphere on Kapp Linné, Svalbard

Abstract. We measured CO2 and CH4 fluxes using chambers and eddy covariance (only CO2) from a moist moss tundra in Svalbard. The average net ecosystem exchange (NEE) during the summer (9 June–31 August) was negative (sink), with −0.139 ± 0.032 µmol m−2 s−1 corresponding to −11.8 g C m−2 for the whole summer. The cumulated NEE over the whole growing season (day no. 160 to 284) was −2.5 g C m−2. The CH4 flux during the summer period showed a large spatial and temporal variability. The mean value of all 214 samples was 0.000511 ± 0.000315 µmol m−2 s−1, which corresponds to a growing season estimate of 0.04 to 0.16 g CH4 m−2. Thus, we find that this moss tundra ecosystem is closely in balance with the atmosphere during the growing season when regarding exchanges of CO2 and CH4. The sink of CO2 and the source of CH4 are small in comparison with other tundra ecosystems in the high Arctic. Air temperature, soil moisture and the greenness index contributed significantly to explaining the variation in ecosystem respiration (Reco), while active layer depth, soil moisture and the greenness index were the variables that best explained CH4 emissions. An estimate of temperature sensitivity of Reco and gross primary productivity (GPP) showed that the sensitivity is slightly higher for GPP than for Reco in the interval 0–4.5 ∘C; thereafter, the difference is small up to about 6 ∘C and then begins to rise rapidly for Reco. The consequence of this, for a small increase in air temperature of 1∘ (all other variables assumed unchanged), was that the respiration increased more than photosynthesis turning the small sink into a small source (4.5 g C m−2) during the growing season. Thus, we cannot rule out that the reason why the moss tundra is close to balance today is an effect of the warming that has already taken place in Svalbard.

Simulation of the Impact of Instantaneous Solar UV Radiation Enhancements on the Middle Atmosphere via UV Radiation Reconstruction

This study reconstructed the 0.01–399.5 nm ultraviolet (UV) radiation band with a time resolution of 5 min under solar minimum conditions (18 October 2006) to investigate the effects of the solar flare event on the middle atmosphere. Five-minute resolution 0.01–399.5 nm UV radiation was used instead of daytime scale data to observe the response of the middle atmosphere to the instantaneous solar UV radiation enhancement. The results indicate that small temperature increases of 0.05 K in low latitudes were observed in the lower thermosphere and the stratosphere. The UV radiation enhancement led to an ozone increase of 0.6% in the stratosphere, which caused small temperature increases; and there is an ozone increase of up to 4% at 80 km, while a change of −2% occurred at 60–70 km and a change of −6% occurred in the low thermosphere. There was a 0.05% increase in atmospheric density above 60 km, and there was an increase of up to 0.15% at 80–90 km. The responses of the atmospheric temperature and density in the middle atmosphere to instantaneous UV radiation enhancements can therefore be captured via the UV radiation reconstruction. The simulation results were weaker than the previous study.

Significance of a 1 °C increase in global temperature

The Intergovernmental Panel on Climate Change reports indicate that the global mean temperature is about 1 °C higher than pre-industrial levels, that this increase is anthropogenic, and that there is a causal relationship between this higher temperature and an increase in frequency and magnitude of extreme weather events. This causal relationship seems at odds with common sense, and may be difficult to explain to non-experts. Thus to appreciate the significance of a one degree increase in global mean temperature, we perform back-of-the-envelope calculations relying on simple physics. We estimate the excess thermal energy trapped in the climate system (oceans, land, atmosphere) from a 1 °C increase in global mean temperature, and show that it is thousands of times larger than the estimated energy required to form and maintain a hurricane. Our estimates show that global warming is forming a very large pool of excess energy that could in principle power heatwaves, heavy precipitation, droughts, and hurricanes. The arguments presented here are sufficiently simple to be presented in introductory physics classes, and can serve as plausibility arguments showing that even a seemingly small increase in global mean temperature can potentially lead to extreme weather events.

Experimental warming reduces body mass but not reproductive investment.

Climate change has already had wide-ranging effects on populations, including shifts in species' ranges, phenology, and body size. Whereas some common patterns have emerged, the direction and magnitude of responses vary extensively among populations as well as across life stages within populations. Understanding the consequences of climate change and predicting future responses at the population level require experimental tests of how warmer temperatures affect life history traits, including growth rate, development time, and reproductive output. Here, we tested how experimental warming affected life history from larval development and survival to adult reproductive maturity and investment in mole salamanders, Ambystoma talpoideum. We found that a small temperature increase (~1°C) experienced during larval development had complex consequences: density-dependent effects on growth and body mass, density-independent effects on fat storage, and no effects on survival and reproductive investment. Although warming reduced growth rates, size at maturity, and fat storage, salamanders in both warmed and control conditions had similar survival and reproductive investment in their first year. However, costs of smaller body size and lower fat reserves may limit overwintering survival and/or future reproduction. Our study highlights the differential effects of warming across life history traits and multifaceted population responses to climate change. This work motivates future studies to examine variation in response to climate change across life stages and life history traits.

Binding and stability properties of PEG2000 to globular proteins: The case of lysozyme

• Lysozyme-PEG interaction was studied using calorimetry and spectroscopic techniques. • A PEG/lysozyme interaction in the low polymer concentration regime occurs. • The interaction process is weak, and it is entropically driven. • At low concentration, PEG induces an increase of the denaturation temperature. Poly(ethylene glycol) is a linear polymer widely used in many biotechnological and industrial applications. It is thought that PEG is an inert polymer and its effect on protein stability and dynamics is essentially due to the excluded volume effect which depends on its concentration. However, increasing evidence suggests that direct interactions can be established between PEG and proteins. With the aim to shed more light on PEG-protein interactions, this work evaluated the enthalpy pair interaction coefficient and the enthalpy cross-interaction coefficient for the system PEG2000-lysozyme. In addition, using calorimetry and spectroscopy, the binding, the stability and the conformational behaviour of lysozyme were evaluated in the low polymer concentration regime. We found that a weak interaction between lysozyme and PEG occurs with a binding constant of 1600 ± 230 M −1 . The interaction process is mainly entropically driven: the release of water molecules associated to protein surface and polymer chains may account for this phenomenon. In addition, we found that the general lysozyme structure was only marginally affected by PEG interaction. A small but significant increase in the denaturation temperature was observed most likely due to weak interactions with the polymer and to the dehydration of protein surface.

Trends and space–time patterns of near‐surface temperatures on Maxwell Bay, King George Island, Antarctica

AbstractThere is growing interest in the international scientific community in characterizing climate variability in Antarctica because of the continent's fundamental role in regulating the world's climate. Researchers have intensively studied the Antarctic Peninsula since the warming that began in the mid‐1950s. This was followed by a subsequent cooling period over the last decades. For this paper, using the available data, we analysed the variability in surface air temperatures at five meteorological stations located on King George Island (KGI) (a subantarctic island that is part of the South Shetland Islands); we also investigated the relationships between the air temperatures and large‐scale atmospheric patterns from 1968 to 2019. In this study we found that summer temperatures are above 0°C from December to March and close to melting temperatures (extreme values) in spring and autumn; consequently, a small increase in temperature can have a significant impact on the cryosphere. The statistical analysis of the mean temperatures confirmed a trend toward cooling during the summer and in the mean monthly maximum temperatures over the 1990s at most of the weather stations whose data we analysed. Analysing the teleconnection patterns showed that the Southern Annular Mode (SAM) had strong, direct, and positive correlations during the autumn and less strong connections in spring, winter, and on an annual scale. Furthermore, we observed a lesser influence of El Niño‐Southern Oscillation (ENSO).

Epoxy Composites Reinforced with ZnO from Waste Alkaline Batteries.

The zinc alkaline battery is one of the most popular sources of portable electrical energy, with more than 300,000 tons being consumed per year. Accordingly, it is critical to recycle its components. In this work, we propose the use of zinc oxide (ZnO) microparticles recovered from worn-out batteries as fillers of epoxy resins. These nanocomposites can be used as protective coatings or pigments and as structural composites with high thermal stability. The addition of ceramic nanofillers, such as ZnO or/and TiO2, could enhance the thermal and mechanical properties, and the hardness and hydrophobicity, of the epoxy resins, depending on several factors. Accordingly, different nanocomposites reinforced with recycled ZnO and commercial ZnO and TiO2 nanoparticles have been manufactured with different nanofiller contents. In addition to the different ceramic oxides, the morphology and size of fillers are different. Recycled ZnO are“desert roses” such as microparticles, commercial ZnO are rectangular parallelepipeds nanoparticles, and commercial TiO2 are smaller spherical nanoparticles. The addition of ceramic fillers produces a small increase of the glass transition temperature (<2%), together with an enhancement of the barrier effect of the epoxy resin, reducing the water diffusion coefficient (<21%), although the maximum water uptake remains constant. The nanocomposite water absorption is fully reversible by subsequent thermal treatment, recovering its initial thermomechanical behavior. The water angle contact (WCA) also increases (~12%) with the presence of ceramic particles, although the highest hydrophobicity (35%) is obtained when the epoxy resin reinforced with recycled flowerlike ZnO microparticles is etched with acid stearic and acetic acid, inducing the corrosion of the ZnO on the surface and therefore the increment of the surface roughness. The presence of desert rose ZnO particles enhances the de lotus effect.

Impact of post-socialist vertical extensions of buildings on outdoor microclimate in collective housing areas: A study of Niš, Serbia

Extensive transformations of large housing estates in postsocialist cities have been the subject of many studies. However, the effects of transformations resulting from urban densification, upon local microclimate, have not been fully determined. This paper addresses this issue by investigating the implications that vertical extension of residential buildings had on microclimatic parameters of thermal comfort (air temperature, mean radiant temperature, wind speed, relative humidity, solar radiation) in three large housing estates in the city of Niš, Serbia. By using ENVI-met software, outdoor microclimate is simulated in two scenarios: (1) original urban setting and (2) current urban setting, after the upgrade of existing buildings with additional floors. For the scenario with upgraded buildings, results indicate a small decrease in daytime air temperature, and small increases in mean radiant temperature and nocturnal air temperature. The effects on air temperature, relative humidity and solar radiation are more visible when upgrading low-rise structures, while the upgrade of high-rise buildings mostly affects wind speed. Research identifies tools and strategies of urban design that help in adapting inherited urban settings to temperature increase, such as positioning vertical extensions to exploit the effects of shading, conceptualizing open space in regard to building form, wind speed and solar radiation, and capitalizing on the cooling potential of trees.

A New Charging Algorithm for Li-Ion Battery Packs Based on Artificial Neural Networks

This paper shows the potential of artificial intelligence (AI) in Li-ion battery charging methods by introducing a new charging algorithm based on artificial neural networks (ANNs). The proposed charging algorithm is able to find an optimized charging current profile, through ANNs, considering the real-time conditions of the Li-ion batteries. To test and validate the proposed approach, a low-cost battery management system (BMS) was developed, supporting up to 168 cells in series and n cells in parallel. When compared with the multistage charging algorithm, the proposed charging algorithm revealed a shorter charging time (7.85%) and a smaller temperature increase (32.95%). Thus, the results show that the proposed algorithm based on AI is able to effectively charge and balance batteries and can be regarded as a subject of interest for future research.

최근 우리나라 도시 인구 변화에 따른 도시화 효과 특성

Recently, population growth has been slowing down in metropolitan cities in South Korea. In this study, we analyzed urbanization effects that reflect the characteristics of recent population growth trends using four different methods. In South Korea, the urbanization effect has recently become weaker. The urbanization effect in South Korea was 24 ~ 49% in the last 48 years (1973 ~ 2020). Similarly, for certain spans of 32 years (1973 ~ 2004) and 24 years (1973 ~ 1996), the urbanization effect values were 30 ~ 64% and 42 ~ 73%, respectively. The recent decline in urbanization effect compared to the early 2000s is related to the decreasing urban population growth. The population growths in the second half of the previous 48 years were only about 14% in big cities and about 50% in small cities compared to the first half. As a result, the urbanization effect in small cities has actually been higher than in big cities. Cluster analysis was also conducted to analyze the relationship between population growth and annual-mean temperature increase in 30 different stations. As a result, temperature increase in more than 60% of the stations considered matched the population growth. Some urban stations have smaller temperature increases than population growth, while some rural stations have higher temperature increases than population growth. Therefore, further research on local environmental factors should be carried out to better understand these local temperature changes.

Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Greases: Influence of Thickener Type and Concentration on Melting, Crystallization and Glass Transition

This study investigates crystallization, melting and glass transition of Li- and Ca-12-hydroxystearate greases in relation to the pour point of the corresponding oils. The base oils for the greases are mineral oil, polyalphaolefin, alkylated naphthalene, propylene glycol, and trimellitate. For the mineral oil-based greases the crystallization temperature Tc increases and the melting temperature Tm decreases upon addition of thickener. The pour point of the mineral oil then is 3 K below Tc and does not properly define the lowest application temperature for mineral oil (MO) based greases. Both thickeners induce a small increase of the glass transition temperature (1–3 K) of the synthetic oils polyalphaolefin, alkylated naphthalene, propylene glycol. The pour point of the base oils correlates well with the onset of the glass transition in the corresponding grease indicated by a sharp increase in grease viscosity. Pure trimellitate with unbranched alkyl chains does not crystallize upon cooling but shows noticeable supercooling and cold crystallization. As the percentage of thickener in corresponding greases increases, more oil crystallizes upon cooling 20 K above the crystallization temperature of the trimellitate without thickener (−44 °C). Here, the thickener changes the crystallization behavior from homogeneous to heterogeneous and thus acts as a crystallization nucleus. The pour point of the base oil does not provide information on the temperature below which the greases stiffen significantly due to crystallization.

Inconsistency in historical simulations and future projections of temperature and rainfall: A comparison of CMIP5 and CMIP6 models over Southeast Asia

The objective of this research was to assess the difference in historical simulations and future projections of rainfall and temperature of CMIP5 (RCP4.5 and 8.5) and CMIP6 (SSP2–4.5 and 5–8.5) models over Southeast Asia (SEA). Monthly historical rainfall and temperature estimations of 13 global climate models common to both CMIPs were evaluated to assess their capability to reproduce the spatial distribution and seasonality of European Reanalysis (ERA) rainfall and temperature. Models were used to determine uncertainty with spatiotemporal variability of rainfall and temperature projections. The CMIP6 GCMs did not appear to perform better than the older CMIP5 in SEA unlike other parts of the globe, except for rainfall. The CMIP6 models showed Kling-Gupta Efficiency (KGE) values in the range of −0.48-0.6, 0.21‐0.85 and 0.66‐0.91 in simulating historical rainfall, maximum temperature and minimum temperature compared to 0.13‐0.46, 0.3‐0.86 and 0.42‐0.92 for CMIP5. The improvement in CMIP6 models in SEA was in the low uncertainty in ensemble simulation. The projections of CMIP5 and CMIP6 showed a relatively smaller increase in temperature with the CMIP6 ensemble when compared to CMIP5 models, while rainfall appeared to decrease. The geographical distribution of the changes indicated a greater increase in temperature in the cooler region than in the warmer region. In contrast, there was increase in rainfall in the wetter region and a smaller improvement in the drier region. This indicates increased homogeneity in temperature spatial variability, but more heterogeneity in rainfall, in the SEA region under climate warming scenarios.