Annual Temperature Profiles Research Articles

Temperature sensitivity of pest reproductive numbers in age-structured PDE models, with a focus on the invasive spotted lanternfly.

Invasive pest establishment is a pervasive threat to global ecosystems, agriculture, and public health. The recent establishment of the invasive spotted lanternfly in the northeastern United States has proven devastating to farms and vineyards, necessitating urgent development of population dynamical models and effective control practices. In this paper, we propose a stage-age-structured system of PDEs to model insect pest populations, in which underlying dynamics are dictated by ambient temperature through rates of development, fecundity, and mortality. The model incorporates diapause and non-diapause pathways, and is calibrated to experimental and field data on the spotted lanternfly. We develop a novel moving mesh method for capturing age-advection accurately, even for coarse discretization parameters. We define a one-year reproductive number ([Formula: see text]) from the spectrum of a one-year solution operator, and study its sensitivity to variations in the mean and amplitude of the annual temperature profile. We quantify assumptions sufficient to give rise to the low-rank structure of the solution operator characteristic of part of the parameter domain. We discuss establishment potential as it results from the pairing of a favorable [Formula: see text] value and transient population survival, and address implications for pest control strategies.

Integrating environmental variability to broaden the research on coral responses to future ocean conditions.

Our understanding of the response of reef-building corals to changes in their physical environment is largely based on laboratory experiments, analysis of long-term field data, and model projections. Experimental data provide unique insights into how organisms respond to variation of environmental drivers. However, an assessment of how well experimental conditions cover the breadth of environmental conditions and variability where corals live successfully is missing. Here, we compiled and analyzed a globally distributed dataset of in-situ seasonal and diurnal variability of key environmental drivers (temperature, pCO2 , and O2 ) critical for the growth and livelihood of reef-building corals. Using a meta-analysis approach, we compared the variability of environmental conditions assayed in coral experimental studies to current and projected conditions in their natural habitats. We found that annual temperature profiles projected for the end of the 21st century were characterized by distributional shifts in temperatures with warmer winters and longer warm periods in the summer, not just peak temperatures. Furthermore, short-term hourly fluctuations of temperature and pCO2 may regularly expose corals to conditions beyond the projected average increases for the end of the 21st century. Coral reef sites varied in the degree of coupling between temperature, pCO2 , and dissolved O2 , which warrants site-specific, differentiated experimental approaches depending on the local hydrography and influence of biological processes on the carbonate system and O2 availability. Our analysis highlights that a large portion of the natural environmental variability at short and long timescales is underexplored in experimental designs, which may provide a path to extend our understanding on the response of corals to global climate change.

Analysis of a HDPE flanged connection with a time and temperature dependent constitutive behavior

High density polyethylene (HDPE) piping systems are used extensively in both industrial and societal infrastructure. However, their performance is sometimes impacted due to leakage through flanges, especially HDPE pipes with large diameters. Many factors affect leakage, including stress relaxation in the HDPE material and ambient temperature effects. Hence, this study investigates the effect of temperature on the leakage of a HDPE flanged connection with steel backing rings. It incorporates the effects of stress relaxation and temperature on the HDPE material and assesses the degradation of performance of the connection with time by means of finite element analysis (FEA). The temperature and time dependent mechanical properties of the HDPE material are determined experimentally through tensile, compression and relaxation testing conducted at various temperatures under isothermal conditions. The constitutive behavior of the HDPE material is modeled using the nonlinear visco-elastic plastic three network model (TNM), which predicts the mechanical behavior of HDPE markedly well. The calibrated TNM is used in the FEA study to investigate the leakage performance of the HDPE connection at various temperatures (23, 40, 60 and 80 °C) at isothermal conditions over a service time of one year. The FEA results reveal that the flanged connection can experience leakage at all temperatures due to insufficient bolt preload. It is also found that leakage occurs prematurely as temperature increases. To simulate a realistic scenario resembling an above ground piping system, an annual temperature profile for a selected geographic location was prescribed to the model to simulate leakage over a one year period. Based on the results, several bolt re-torqueing plans were explored and suggestions are made on the best bolt re-torqueing practice for preventing leakage over the service life of the HDPE connection.

Annual temperature profile of Thrissur: a climate change perspective

Annual temperature profile of Thrissur: a climate change perspective

Functional data analysis in the Banach space of continuous functions

Functional data analysis is typically conducted within the $L^{2}$-Hilbert space framework. There is by now a fully developed statistical toolbox allowing for the principled application of the functional data machinery to real-world problems, often based on dimension reduction techniques such as functional principal component analysis. At the same time, there have recently been a number of publications that sidestep dimension reduction steps and focus on a fully functional $L^{2}$-methodology. This paper goes one step further and develops data analysis methodology for functional time series in the space of all continuous functions. The work is motivated by the fact that objects with rather different shapes may still have a small $L^{2}$-distance and are therefore identified as similar when using a $L^{2}$-metric. However, in applications it is often desirable to use metrics reflecting the visualization of the curves in the statistical analysis. The methodological contributions are focused on developing two-sample and change-point tests as well as confidence bands, as these procedures appear to be conducive to the proposed setting. Particular interest is put on relevant differences; that is, on not trying to test for exact equality, but rather for prespecified deviations under the null hypothesis. The procedures are justified through large-sample theory. To ensure practicability, nonstandard bootstrap procedures are developed and investigated addressing particular features that arise in the problem of testing relevant hypotheses. The finite sample properties are explored through a simulation study and an application to annual temperature profiles.

Cimate Change-Related Temperature Increases and Associated Health Risks for Cities in the Shue Database

Introduction: Climate change and increasing urbanization are expected to increase the risk of temperature-related impacts on health for many of the world’s cities. We explored the nature of the likely temperature changes by 2050 under climate change in relation to city characteristics and health vulnerability. Methods: The SHUE database contains 309 randomly-selected global cities, stratified by population, wealth, and climate region, with data on city characteristics compiled from existing sources. Current and future (2050) monthly temperature distributions for each city were estimated from downscaled results of ensembles of 11 climate model runs under Representative Concentration Pathway 6.0. For each city’s 2050 climate, the city with the most similar current climate was identified (its ‘climate analogue’). Where available, city-specific temperature-mortality functions were used to estimate changes in health burdens. Results: Temperature changes by 2050 varied appreciably from city to city and model to model (median +1.9 °C, range -3.5 to +7.3 °C) but were generally largest in summer months, at northern latitudes and in wealthier cities, with the greatest increases in Europe and North America. One of the largest estimates of change is for Sofia (median +3.4 °C) which would translate to a 9.8% increase in mortality in the hottest month, assuming no adaptation and linear extrapolation of risk beyond the upper end of the current temperature distribution. For most cities and climate models, annual temperature profiles in 2050 remain similar to the present day profiles of other cities in the same climatic zone. Conclusions: Insights into future heat-related health burdens may be gained by understanding how a city’s 2050 temperature distribution is approximated by the present day climate patterns of other cities. However, the scope for studying climate analogues beyond 2050 is reduced due to the much greater anticipated increases in temperatures.

The significance of using local predicted temperature for cooling load simulation in the tropics

In building energy simulation, researchers commonly use weather data obtained from the software database or (meteorological) MET station. However, this method leads to disparity of urban-rural temperature condition, hence the input weather data do not characterize the on-site condition. This paper highlights the importance of generating and implementing the urbanized weather data, primarily on the ambient temperature. A parametric approach was used to create hundreds urban layouts of the hypothetical office block plan. An annual temperature profile was generated for each scenario using the Screening Tool for Estate Environment Evaluation (STEVE) tool. It was found that the local average temperature (Tavg) and peak afternoon period (Tmax) from these scenarios could differ 1–2°C and 1.2–3.5°C respectively as compared to the MET station data. Using Integrated Environmental Solutions (IES) to simulate the thermal load performance, this temperature difference can lead to an approximately 8% difference in the predicted cooling load, 20% in external conduction gain, and 17% in fresh air intake gain. These numbers can be deemed substantial in simulating building performance, especially cooling load due to changes in the external condition. Furthermore, the comparison proves to be significant in term of enhancing the simulation result and representing the studied area.

Modeling and analysis of a temperature-driven outbreak of waterfowl disease in the Upper Mississippi River

Bithynia tentaculata is an invasive snail that was discovered in the Upper Mississippi River (UMR) in 2002. In addition to being a threat to native benthos, the snail also harbors parasite associated with annual outbreaks of waterfowl mortality in the UMR. Trophic transmission of parasites between snails and birds occurs during seasonal waterfowl migrations, which can depend intimately on temperature. We developed an annual model for waterfowl disease in the UMR where transmission depends on water temperatures gleaned from empirical studies. By running simulations from annual temperature profiles selected randomly from a normal distribution, we quantified the association between the number of infected hosts and annual average temperatures. Model output demonstrated that as annual average temperatures rise, infected host populations initially increase and then decay after temperatures exceed a certain threshold. Results from this work suggest that increasing temperatures in the region may have a negative effect on parasites, decreasing their transmission and reducing infected host populations.

The effect of environmental conditions on the operation of a hydrogen refuelling station

In this study, the effect of environmental conditions on plant operation was investigated for hydrogen refuelling stations with an external storage facility. Hydrogen storage pressure with respect to tank surface temperatures have been measured and used to create empirical equations for each tank showing the effect of surface temperature on the tank pressure. A physical model of the hydrogen storage tanks has been created in DesignBuilder (EnergyPlus) to simulate the surface temperature of tanks throughout the course of a year with respect to location, site orientation, tank size and surface colour, shading and operating pressure. Finally, the effect that environmental conditions may have on a plant operation is assessed through the prediction of pressure dependent events, namely the frequency of alarms and pressure relief occurrences and hours of plant downtime over the course of a year. The modelling results indicate that location, tank size, surface colour and sunshade can have substantial impacts on the plant operation, whereas the influence of site orientation is less significant. Frequency of pressure dependant events increase as the tank size decreases due to more significant heat gain observed with higher surface-to-volume ratios. Simulation results also prove that the provision of a sunshade or white paint colour could avoid/minimise the interference of ambient conditions in plant operation in cold and mild climates. However, they are not sufficient enough to mitigate against solar gain effect in warmer climates. Although reducing the maximum operating pressure would also help reduce the number of solar gain pressure events, it would also result in increased cushion level and hence reduced plant performance. The optimum design and operating strategy should be chosen for each individual station considering the daily and annual temperature profiles of the location.

Are Yellowstone Lake Temperatures More Suitable to Nonnative Lake Trout than to Native Cutthroat Trout?

AbstractA recent study revealed limitations to the reproduction potential of Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri (YCT) in Yellowstone Lake, Wyoming, resulting from suboptimal conditions for somatic growth. The present study evaluated the lake as suitable thermal habitat for YCT and lake trout Salvelinus namaycush, a highly piscivorous, nonnative species, a reproducing population of which was discovered there in 1994. Because the fundamental thermal niche of lake trout delimits a zone of the lake's annual temperature profile that surrounds the corresponding, separate zone for YCT, the annual growing season and volume of suitable Yellowstone Lake habitat will invariably be larger for lake trout than YCT across the range of cool‐to‐warm climate years. Ongoing management actions to control lake trout emphasize intensive gill netting, while temporal changes in lake trout catch rates and population structure provide metrics of program success. However, the limits to YCT reproduction potential attributed to the short growing season make the YCT population especially susceptible to lake trout predation, perhaps even from a measurably reduced predator population. Identification of such effects requires that dynamic, age‐structured models of the YCT population that incorporate all important population drivers be formulated and used in data analyses and control program assessment.Received February 5, 2012; accepted May 8, 2012

Sensitivity Analysis of the Pressure-Based Direct Integrity Test for Membranes Used in Drinking Water Treatment

We conducted a sensitivity analysis of the commonly employed pressure-based direct integrity test (DIT), the most sensitive test for defects in low-pressure hollow fiber (LPHF) microfiltration and ultrafiltration systems used in drinking water treatment. Incorporating uncertainty to assess the practice of DIT, we find the resolution in some tests may be insufficient to verify the presence of a barrier to oocysts of Cryptosporidium. Applying distributions and boundaries derived from literature and practice, we solved for the defect size resolution (DSR) using Monte Carlo and Probability Bounds Analysis for five commercial membrane designs. Surface tension was modeled using annual temperature profiles from three rivers. Contact angle measurement error and variability were derived from literature, respectively, as a standard deviation of 5.7 degrees and +/- 9.6 degrees median change due to natural organic matter (NOM) fouling. These measures of contact angle uncertainty and variability were combined in a normal distribution with the discrete values currently applied. Additionally we considered model uncertainty, applying the maximum bubble pressure method, an established method of surface tension measurement in liquids in which the maximum air pressure in a submerged capillary is developed after the contact angle becomes zero prior to bubble formation. Where the DSR exceeds 3 microm the test design is not compliant with applicable drinking water regulations. Implications include uncertain and variable log-removal values (LRV) as determined by DIT due to the possible emergence of defects large enough to allow oocysts to pass without detection by the DIT. Specifically, we found the DSR may exceed 3 microm and may be as large as 8 microm. With the variable contact angle model, all lower bound possibilities are compliant, whereas the upper bound is over 80% noncompliant for three of five commercial designs. Using the Maximum Bubble Pressure Method, the lower bounds in three designs start to exceed 3 microm for between 50 and 100% of the produced water, whereas the upper bounds of the DSR completely exceed 3 microm for four of five commercial designs examined.

Atmospheric stability and gravity wave dissipation in the mesopause region

High-resolution temperature profile data collected at the Urbana Atmospheric Observatory (40°N, 88°W) and Starfire Optical Range, NM (35°N, 106.5°W) with a Na lidar are used to assess the stability of the mesopause region between 80 and 105 km . The mean diurnal and annual temperature profiles demonstrate that in the absence of gravity wave and tidal perturbations, the background atmosphere is statically stable throughout the day and year. Thin layers of instability can be generated only when the combined perturbations associated with tides and gravity waves induce large vertical shears in the horizontal wind and temperature profiles. There is a region of reduced stability below the mesopause between 80 and 90 km where the temperature lapse rate is large and the buoyancy parameter N 2 is low. The vertical heat flux is maximum in this region which suggests that this is also a region of significant wave dissipation. There is also a region of enhanced stability above 95 km in the lower thermosphere where N 2 is large. There appears to be little wave dissipation above 95 km because the temperature variance increases rapidly with increasing altitude in this region and the vertical heat flux is zero.

Effect of temperature on the growth rates of halotolerant and halophilic bacteria isolated from Antarctic saline lakes

The effect of temperature on the growth rates of Halomonas subglaciescola and a Halobacterium sp., halotolerant and halophilic bacteria isolated from Antarctic saline lakes, was predicted accurately by models which propose a linear relationship between temperature and the square root of the reciprocal of the growth rate. The cardinal temperatures of the strains examined were in general 5–10°C lower than those of taxonomic counterparts isolated from temperate and tropical environments. Temperature dependence data for strains of the Halobacterium sp. and annual temperature profiles of Deep Lake allowed estimation of the in situ potential for growth.

Respiratory metabolism in pacifastacus leniusculus (Dana) (crustacea: decapoda) as related to its ecology

Respiratory metabolism in the high-altitude crayfish, Pacifastacus leniusculus from Lake Tahoe (California-Nevada, U.S.A.) was investigated in a series of laboratory experiments. In general, oxygen consumption was found to be directly proportional to size when expressed per individual, and inversely proportional to size when expressed per ash-free gram dry weight per unit time. No significant variations in respiratory rates were observed between males and females. There was little variation in uptake over a temperature range of 5°C to 12.5°C, while the lowest and highest uptake values were observed at 0°C and 15°C respectively. An increase in temperature above 15°C, however, resulted in a decrease in respiratory activity. These results closely correlate with patterns of ventilatory activity, oxygen extraction efficiency, and seasonal feeding and reproductive activity in Pacifastacus as related to the annual temperature profile for their Lake Tahoe habitat.

A new model of thermal diffusion in a translucent medium

The thermal diffusion equation is solved analytically for an ideally translucent and homogeneous medium with an internal, distributed heat source given by the penetration and absorption of solar radiation. The mean annual temperature profile has the coldest values at the surface; the mean annual flux of sensible heat out of the medium balances the internally absorbed solar radiation for the case of constant mean annual temperatures. A new formula is developed for the evaluation of the true thermal diffusivity of a non-homogeneous conductor from the Fourier components of the waves of insolation and temperature; a constant extinction coefficient is assumed. The new model is applied with moderate success to data from the coastal plateau ice at Mawson, Antarctica.