Temperature Variability Research Articles

Elderly vulnerability to temperature-related mortality risks in China.

The elderly face elevated mortality risk due to rising temperature. Previous assessments of temperature-related mortality, however, lack a comprehensive analysis of distinct impacts of temperature change across different timescales and characteristics. Using a longitudinal survey of 27,233 elderly Chinese citizens from 2005 to 2018, we establish connections between rising temperatures, temperature variability, and extreme heat with increased mortality risk, assessed through four annual metrics that combine temperature and humidity. The intensity and prolonged duration of extreme heat are found to have the greatest impact on mortality risk. Furthermore, by identifying heterogeneous impacts based on location, sex, age, obesity, income, and diet, we reveal the pathways through which temperature metrics are likely to influence mortality risk. Our study highlights the compound effects of rising temperatures for elderly populations, and it could be expanded to other countries and regions experiencing similar challenges due to an aging population experiencing warming conditions.

When Simplification Leads to Ambiguity: A Look at Two Ocean Metrics for the Subpolar North Atlantic

AbstractThe AMOC FINGERPRINT and GYRE INDEX are two widely used metrics by the oceanographic community to assess whether northward ocean heat transport, and consequently temperature variability in the subpolar North Atlantic, is primarily governed by the Atlantic overturning circulation or the horizontal gyre circulation. Although these metrics are presented as distinct measures of subpolar ocean circulation, we contend that they are not unique indicators of the dynamics they are intended to represent. Instead, our analysis demonstrates that both metrics are essentially capturing variability in upper ocean heat content, which can result from a number of mechanisms. This conclusion, corroborated with direct overturning measurements from the OSNAP and RAPID programs, raises concerns about the use of these metrics to infer the dynamics responsible for past and projected changes in subpolar ocean temperatures.

Analytical Model for the Higher Order Moments of Midlatitude Atmospheric Temperature Distributions

AbstractObserved distributions of atmospheric temperature are non‐Gaussian. Therefore, moments beyond variance are necessary in determining the frequency of extreme temperature events. Here we propose a simple kinematic model for atmospheric mid‐latitude temperature variability based on symmetric advection from a non‐symmetric background temperature profile. We then use this model to derive analytical expressions for the higher order moments of temperature distributions. Our results show that nonzero skewness and kurtosis arise due to the nonlinearity of the time‐mean meridional temperature profile. The analytical model matches an idealized Held‐Suarez atmospheric model, indicating nonlinearity of time‐mean temperature in latitude is the dominant contribution to nonzero skewness and kurtosis in synoptic temperature variations. Model analysis further shows decrease in higher order moments due to climate change come roughly equally from changes in mixing length and changes in the background temperature profiles.

Intraseasonal Air Temperature Variability and Its Trends Are Sensitive to the Definition of Daily Mean Temperature: Germany as a Case Study

Abstract Our previous research on trends in summer day-to-day mean temperature difference in Europe indicates inhomogeneities to occur at climate stations in Germany. In most cases, they produce an unrealistic decreasing trend. It is suggested that these discontinuities are caused by the change in daily mean temperature calculation in April 2001, from averaging the temperature at 7, 14, and two times 21 to averaging all 24-hourly values. This study demonstrates this inhomogeneity and uncovers the difference in climatology and trends of summer temperature variability between aforesaid definitions of daily mean temperature at 13 stations in Germany. It is revealed that the choice of definition is crucial for seasonal temperature variability while for seasonal mean temperature itself no difference between definitions is noticed. The first definition [(T7 + T14 + 2 × T21)/4] shows days after warming warmer and days after cooling colder than if averaging all 24 observations, which is the reason for overestimated intraseasonal temperature variability before 2001 and for its artificial decreasing trends.

Corrigendum to “Biomarker reconstructions of temperature and hydroclimate variability in Vietnam during Marine Isotope Stage 3” [Quat. Sci. Rev. 341 (2024) 108893]

Corrigendum to “Biomarker reconstructions of temperature and hydroclimate variability in Vietnam during Marine Isotope Stage 3” [Quat. Sci. Rev. 341 (2024) 108893]

Interdecadal changes in three-dimensional atmospheric circulation patterns related to summer temperature variability in Eastern China modulated by the interdecadal Pacific Oscillation

Abstract The dynamic effects of three-dimensional atmospheric circulation patterns are critical for regulating both regional and global climates. By using the three-pattern decomposition of global atmospheric circulation (3P-DGAC), this study recognizes the interdecadal changes of three-dimensional atmospheric circulation patterns associated with summer temperature anomalies in the middle and lower reaches of Yangtze River (MLRYR), and further demonstrates that these related changes of atmospheric circulation patterns are modulated by the Interdecadal Pacific Oscillation (IPO). During the positive phase of the IPO, the three-dimensional atmospheric circulation patterns are characterized by the anticyclonic high at the middle and upper troposphere, and anomalous downdrafts along local meridional circulation near MLRYR. Then, in the negative phase of the IPO, alongside the aforementioned atmospheric circulation patterns, there are anomalous downdrafts along the local zonal circulation at the Eastern Tibetan Plateau (ETP). Through statistical and dynamical analysis, the emergence of local zonal circulation is attributed to the influences of positive sea surface temperature anomalies in North Atlantic during the negative phase of the IPO, which propagate to East Asia through intensified jet stream waviness. The findings of this study establish a synchronous linkage between ETP climate and downstream regions, offering significant implications for enhancing seasonal climate forecasting in the future.

Exploring air temperature variability and socio-demographic inequalities in heat exposure through machine learning: A case study of Maricopa County, Arizona

Exploring air temperature variability and socio-demographic inequalities in heat exposure through machine learning: A case study of Maricopa County, Arizona

Modelled Water Temperature Patterns and Energy Balance of a Threatened Coastal Lagoon Ecosystem

ABSTRACTCoastal water temperatures control physical, chemical, and biological processes and are expected to rise due to future changes in freshwater temperature and flow rates, heat exchange with the warming atmosphere, and thermal interactions with a changing ocean. However, the thermal sensitivity of transitional, coastal water bodies to climate change remains poorly understood, due partly to a lack of knowledge on present‐day thermal controls in these settings. Accordingly, we applied a coastal hydrodynamic model (MIKE 3 FM), with a coupled thermal module to simulate hydrodynamics and water temperature variability in the Basin Head lagoon, a federally protected coastal ecosystem in the Canadian province of Prince Edward Island. Field data from the lagoon were used to calibrate and assess the numerical model, while atmospheric, oceanic, and hydrologic data were used to form the thermal and hydrodynamic boundary conditions. The model successfully reproduced tidal water level oscillations as well as diurnal and semi‐diurnal (tidal) temperature fluctuations. Model results show longitudinal, cross‐shore, and vertical thermal variability within the lagoon, including pronounced thermal variability near the bed and near the inlet due to tidal pumping. Model results and field data highlight the thermal sensitivity of the lagoon during heat waves; however, distinct cold‐water plumes at freshwater inputs (springs and groundwater‐dominated streams) persisted, with temporally averaged temperatures in these zones up to 18 °C colder than the ambient lagoon. Although, these freshwater inflows can dominate local energy budgets, the surface heat fluxes, especially shortwave radiation, exert the dominant control on the lagoon‐wide energy budget. Collectively, the model findings emphasise the interacting effects of atmospheric, hydrologic, and oceanic forcing on the spatiotemporal patterns of water temperatures in this threatened coastal ecosystem.

ENSO and volcanic forcing of winter and summer interannual temperature variability in East Asia over the past six centuries

ENSO and volcanic forcing of winter and summer interannual temperature variability in East Asia over the past six centuries

Analysis of past and future temperature variability and change in Southern Ethiopia

Purpose This study aims to analyze the temperature variability and change for the past 30 years (1990–2019) and the future 60 years (2030s, 2050s and 2070s) in Wolaita Zone and the surroundings, in Southern Ethiopia. Design/methodology/approach The temperature (maximum and minimum) data of the past 30 years (1990–2019) of ten meteorological stations and the future (2021–2080) data of regional climate models (RCMs) under two representative concentration pathways (RCP4.5 and RCP8.5) were used in this study. The accuracy of RCMs in representing observed temperature data was evaluated against mean absolute error, root-mean-square error, percent bias, Nash–Sutcliffe measure of efficiency, index of agreement (d) and coefficient of determination (R2). The temperature variability was analyzed using the coefficient of variation, and the trend was determined using the Mann–Kendall trend and Sen’s slope tests. Findings The results indicate that the past maximum (Tmax) and minimum (Tmin) temperatures showed low variability (CV = 4.3%) with consistently increasing trends. Similarly, Tmax and Tmin are projected to have low variability in the future years, with upward trends. The Tmax and Tmin are projected to deviate by 0.7°C–1.2°C, 1.3°C–2.2°C and 1.5°C–3.2°C by 2030s, 2050s and 2070s, respectively, under RCP4.5 and RCP8.5, from the baseline. Thus, it can be concluded that temperature has low variability in all periods, with consistently increasing trends. The increasing temperature could have been affecting agricultural production systems in Southern Ethiopia. Research limitations/implications This research did not remove the uncertainties of models (inherited errors of models) in future temperature projections. However, this study did not have any limitation. Therefore, individuals or organizations working on agricultural productivity, food security and sustainable development can use the results and recommendations. Practical implications The globe has been warming due to the increasing temperature; as a result, many adaptation and mitigation measures have been suggested globally and nationally (IPCC, 2021). FAO (2017) indicates that the level of vulnerability to the impacts of climate change varies with geographic location, economy and demography; the adaptation measures need to be local. The detailed information on temperature variability and change in the past and future helps to understand the associated negative impacts on agriculture, hydrology, biodiversity, environment and human well-being, among others. Social implications The projected future climate pattern helps the country devise proactive adaptation and mitigation measures for the associated damages at different levels (from local to national). This could improve the resilience of farmers and the country to climate change impacts. This contributes to achieving sustainable development goals (e.g. no poverty, zero hunger and climate action). This is because the agriculture sector in Ethiopia accounts for 80% of employment, 33% of the gross domestic product and 76% of exports (EPRSS, 2023). Originality/value Temperature is one of the major climate elements affecting agricultural production in rain-fed production systems. Despite this, past studies in Southern Ethiopia considered only the past temperature but not the future climate. Thus, generating detailed information about past and future temperatures is very important to take proactive adaptation measures for reducing climate-associated damages in the agriculture sector in Ethiopia.

Impact of Victoria Mode on Late‐Season Tropical Cyclone Genesis Over the Western North Pacific

AbstractThe Victoria Mode (VM) plays a vital role in shaping Pacific Sea Surface Temperature (SST) variability. However, its impact on late‐season tropical cyclone genesis (TCG) over the western North Pacific (WNP) remains underexplored. This study investigated the influence of VM on WNP TCG from 1965 to 2020. Significant relationships emerge in interannual (6 year) and decadal (11 year) timescales. On the interannual timescale, VM correlates positively with TCG west of 145°E and negatively to the east. On the decadal timescale, the negative relationship spans the entire WNP. Victoria Mode directly modulates vertical motion and induces low‐latitude anticyclonic circulation across the low‐latitude North Pacific by altering surface wind convergence and diabatic heating. This, in turn, shapes environmental conditions, affecting TCG. Dynamic factors are more important in WNP TCG changes than thermodynamic factors. Critical environmental conditions in VM's impact on TCG include four dynamic factors: relative vorticity, vertical velocity, meridional gradient of zonal wind, and vertical shear of zonal winds. Vertical shear of zonal winds is particularly influential. Distinct correlation patterns and mechanisms are diagnosed between different timescales, attributed to anomalous SST observed over the WNP on the interannual timescale but not on the decadal timescale. Furthermore, this study illustrates the complexity of region‐ and time‐dependent relationships between environmental conditions and TCG. Such dependencies pose challenges for conventional genesis potential index models in accurately capturing the spatial characteristics of the VM‐TCG relationship. Overall, our findings uncover VM's substantial influence on WNP TCG, enhancing understanding of key environmental conditions and mechanisms driving interannual and decadal TCG variations.

Temperature-dependent variations in under-canopy herbaceous foliar diseases following shrub encroachment in grasslands

Shrub encroachment into grasslands poses a global concern, impacting species biodiversity and ecosystem functioning. Yet, the effect of shrub encroachment on herbaceous diseases and the dependence of that effect on climatic factors remain ambiguous. This study spans over 4,000 km, examining significant variability in temperature and precipitation. Our findings reveal that herbaceous plant species richness diminishes the pathogen load of foliar fungal diseases of herbaceous plants in both shrub and grassland patches. Temperature emerges as the primary driver of variations in herbaceous biomass and pathogen load within herbaceous plant communities. Disparities in herbaceous biomass between shrub and grassland patches elucidate changes in pathogen load. In colder regions, shrub encroachment diminishes herbaceous biomass and pathogen load. Conversely, in warmer regions, shrubs either do not reduce or even amplify pathogen load. These discoveries underscore the necessity for adaptive management strategies tailored to specific shrub encroachment scenarios.

A sub-fossil coral Sr∕Ca record documents northward shifts of the Tropical Convergence Zone in the eastern Indian Ocean

Abstract. Sea surface temperature (SST) variability in the south-eastern tropical Indian Ocean is crucial for rainfall variability in Indian Ocean rim countries. A large body of literature has focused on zonal variability associated with the Indian Ocean Dipole (IOD) which peaks in austral spring. In today's climate, northward shifts of the Tropical Convergence Zone (TCZ) co-vary with the IOD, and it is unclear whether these shifts may also occur independently. We have developed a new monthly resolved Sr/Ca record from a sub-fossil coral cored at Enggano Island (Sumatra, Indonesia). Core sections containing diagenetic phases are omitted from the SST reconstruction. U/Th dating shows that the Sr/Ca-based SST record extends from 1869–1918 and from 1824–1862 with a relative age uncertainty of ±3 years (2σ). At Enggano Island, coastal upwelling and cooling in austral spring impact SST seasonality and are coupled to the latitudinal position of the TCZ. The sub-fossil coral indicates an increase in SST seasonality between 1856 and 1918 relative to the 1930–2008 period. We attribute this to enhanced cooling due to stronger south-easterly (SE) winds driven by a northward shift in the TCZ in austral spring. A nearby sediment core indicates colder SSTs and a shallower thermocline prior to ∼1930. These results are consistent with an increase in the north–south SST gradient in the eastern Indian Ocean, calculated from historical temperature data, that is not seen in the zonal SST gradient. We conclude that the relationship between meridional and zonal variability in the eastern Indian Ocean is non-stationary and modulated by the long-term evolution of temperature gradients.

Predicting temperature variability in major Indian cities using Random Forest Regression (RFR) Model

Predicting temperature variability in major Indian cities using Random Forest Regression (RFR) Model

Evolving threats in an unforgiving climate: impact of non-optimal temperatures on life expectancy

This study examines how climate conditions influence life expectancy in Europe based on the impact of year-to-year temperature variability adjusted for economic changes. By focusing on a narrow range of ambient temperatures, we made the model sensitive to both extreme weather and moderately adverse conditions, such as low-temperature modulation of the winter infection season. Regional trend estimates from 1990 to 2019 were pooled to evaluate the overall relationship. We also assessed climate change impacts from 1979–1982 to 2019–2022 and 1981–2010 to 2041–2070 under the RCP 4.5 scenario. Colder-than-optimal temperatures had a greater effect on mortality than warmer ones. In Europe’s coldest regions, harsh winters reduced life expectancy by up to 24 months, while warmer areas like the Azores saw reductions of just 2 months. Overall, climate change has had a small impact in Northern Europe: life expectancy increased by about 1 month due to milder winters but decreased by half a month due to hotter summers. In Southern Europe, the effects were mixed: Atlantic regions gained up to 3 months, while Mediterranean-bordering areas lost up to 3 months. Economic growth maintained a modest effect on life expectancy, even in highly developed regions. Assuming unchanged vulnerability, due to warmer winters life expectancy should be increased by a month, but regions south of the Alps this would be offset by higher heatwave-related deaths.

Diatom responses to rapid light and temperature fluctuations: adaptive strategies and natural variability

Diatoms are crucial in global primary productivity and carbon sequestration, contributing significantly to marine food webs and biogeochemical cycles. With the projected increase in sea surface temperatures, climate change poses significant threats to these essential organisms. This study investigates the photobiological responses of nine diatom species to rapid changes in light and temperature, aiming to understand their adaptability and resilience to climate-induced environmental fluctuations. Using a high-throughput phenoplate assay, we evaluated the maximum quantum yield of photosystem 2 (Fv/Fm), non-photochemical quenching (NPQ) and additional photosynthetic parameters under varying temperature conditions. Our results revealed significant variability in the photophysiological responses among the species, with temperature emerging as a dominant abiotic factor relative to light, accounting for 13.2%–37.5% of the measured variability. Measurements of effect size of temperature and light on Fv/Fm showed that there is additional significant innate variability in the samples when a homogeneous culture is fractioned in 384 subpopulations. Furthermore, hierarchical clustering analysis of the effect size of temperature, light and innate variability on all measured photosynthetic parameters identified two distinct diatom groups. One group exhibited strong interaction between light intensity and temperature, suggesting active synergetic mechanisms to cope with fluctuating environments, while the other showed potential limitations in this regard. These findings highlight diatoms’ diverse strategies to optimize photosynthesis and manage light and thermal stress, providing insights into their potential responses to future climate scenarios. Furthermore, we demonstrate that using the method presented in this work we can functionally cluster different diatom species.

Spatial, environmental and trophic niche partitioning by seabirds in a climate change hotspot.

For similar species to co-occur in places where resources are limited, they need to adopt strategies that partition resources to reduce competition. Our understanding of the mechanisms behind resource partitioning among sympatric marine predators is evolving, but we lack a clear understanding of how environmental change is impacting these dynamics. We investigated spatial and trophic resource partitioning among three sympatric seabirds with contrasting biological characteristics: greater crested terns Thalasseus bergii (efficient flyer, limited diver, and preference for high quality forage fish), little penguins Eudyptula minor (flightless, efficient diver, and preference for high quality forage fish) and silver gulls Chroicocephalus novaehollandiae (efficient flyer, limited diver and generalist diet). We investigated interannual variability in resource partitioning in relation to environmental variability in a climate change hotspot influenced by the warm and intensifying East Australian Current (EAC). Sampling was conducted from 2012 to 2014 during the austral summer breeding season of seabirds at Montague Island, Australia. Daily seabird movements were monitored using GPS trackers and feather tissues were collected and processed for stable isotope analysis (δ15N and δ13C). Generalised Linear Mixed Models were used to assess how changes in oceanographic conditions influenced space use for each species. Schoener's D and Bayesian mixing models were used to respectively investigate the levels of yearly inter-specific environmental and trophic niche overlaps. Crested terns and little penguins were less likely to be observed in warm, saline EAC waters and crested terns and silver gulls had smaller foraging areas on days when more than 30% of available habitat was classified as EAC origin. All species preferred areas with low variability in sea surface temperature (<0.5°C). Terns and penguins occupied similar marine trophic levels, with penguins having larger isotopic niche spaces in 2014 when the EAC was more dominant in the study area. Gulls occupied the lowest trophic level, with the widest niche and lowest interannual variability in niche area. As the EAC intensifies along the southeast coast of Australia under climate change, interspecific competition for resources may increase, with the greatest impacts on species like little penguins that have relatively restricted foraging ranges. This study suggests that species-specific biological traits and behavioural plasticity should be accounted for when predicting the effects of climate change on marine species.

Application of Finite Pointset Method to Study Two‐Way Coupled Transient Bio‐Thermoelastic Effects in Skin Tissue

ABSTRACTIn this research, we introduce the finite pointset method as an innovative approach for approximating transient linear thermoelasticity in biological tissue, addressing the complex interplay between thermal and elastic effects under three distinct shock conditions. Numerical simulations are performed to solve the coupled thermoelasticity equations, demonstrating the temperature distribution, displacement, and stress profiles within the tissue. The results highlight the influence of shock conditions on the thermal and mechanical responses of the tissue, emphasizing the impact of coupling parameter and perfusion rate. Numerical simulations are applied to several benchmark thermoelasticity problems, providing numerical results that validate the approach. Notably, our findings reveal the cooling effects induced by perfusion under both coupled and uncoupled scenarios and highlight the variability of temperature, displacement and stresses based on the coupling parameter. This work contributes to the field of biomedical engineering by providing insights into tissue behavior under thermal stress and offering potential applications in medical technology and therapeutic interventions. The use of FPM not only enhances the accuracy of modeling thermal and mechanical effects in biological tissues but also paves the way for advancements in medical technology. These findings have the potential to inform the development of new therapeutic strategies, particularly in areas related to laser treatments, thermal therapies, and other medical interventions requiring precise control of temperature and stress within tissues.

Influence of precipitation and temperature variability on anthropogenic nutrient inputs in a river watershed: Implications for environmental management.

Since the Industrial Revolution, anthropogenic activities have substantially increased the input of nitrogen (N) and phosphorus (P) into river watersheds, exacerbated by uncertainties stemming from climate change. This study provided a detailed analysis of N and P inputs within the Dawen River Watershed in China from 2000 to 2021. The Net Anthropogenic Nitrogen Input (NANI) and Net Anthropogenic Phosphorus Input (NAPI) methods were used in study, which aimed to investigate how they respond to various climate change factors. Our findings reveal a generally decreasing trend in NANI, with an average of 17,882.34kg/km2/yr. NAPI showed an initially increasing and then decreasing trend, with an average value of 5151.79kg/km2/yr. Fertilizer usage emerged as the primary sources of nutrient inputs, accounting for approximately 63.42% of N and 61.88% of P inputs. Precipitation positively impacted the NANI and NAPI while temperature exerted more influential but opposing effects. Lag effects were evident as demonstrated by the stronger impacts of temperature in preceding year on NANI and NAPI. Moreover, climate not only influenced the quantity of NANI and NAPI but also impacted their changes, as well as the inputs of their components. Through quantitative analyses, we unveiled key thresholds in the correlation between nutrient inputs and climate variables, with cutoffs of 14.1°C in temperature and 820mm in precipitation. Our study highlights the complex relationships between anthropogenic nutrient inputs and climate change, and identifies critical climate thresholds that underscore the importance of sustainable management practices in the Dawen River Watershed to mitigate negative environmental impacts.

GOLD Observations of Thermospheric Neutral Temperature Variability During the 14 October 2023 Annular Solar Eclipse

AbstractThe 14 October 2023 annular solar eclipse was visible from the US Pacific coast to Brazil's east coast. NASA's Global‐scale Observations of Limb and Disk (GOLD) mission observed the first synoptic thermospheric temperature changes from a geo‐stationary orbit above 47.5°W longitude between 17 and 20 UT during the eclipse. These daytime thermospheric changes were derived using GOLD's disk far ultraviolet (FUV) measurements. A significant decrease in the daytime disk temperatures (∼100 K) was seen near the peak annularity compared to the day before (baseline). The temperature reduction's spatial morphology is also like that of the eclipse shadow. Previous modeling studies of other eclipses typically show a much smaller temperature decrease (∼30–40 K; a factor of 2–3 lower) compared to GOLD observations. These first of kind results provide new insight into the dynamic response of the coupled thermosphere and ionosphere system to transient solar events, including eclipses.