Temperature Patterns Research Articles

Atmospheric Teleconnections Responsible for the Dominant Patterns of Interannual Variability in Summer Drought over Northern Asia

Abstract Summer drought over northern Asia (NA) seriously threatens the local fragile ecological environment and social economy development. In this study, using the standardized precipitation evapotranspiration index (SPEI), we first identify the dominant modes of interannual variability in summer drought condition over NA and then explore the atmospheric patterns responsible for the formation of the modes. The results show that the first empirical orthogonal function (EOF1) mode of summer SPEI over NA exhibits a meridional dipole pattern, which is influenced primarily by the polar–Eurasian teleconnection (POL) and circumglobal teleconnection (CGT) patterns. Under the influence of negative POL and positive CGT patterns, there is an anomalous anticyclone (cyclone) over northwestern Siberia (Lake Baikal to Northeast China). Such atmospheric circulations lead to meridional dipole patterns in air temperature, moisture condition, vertical motion, and cloud cover over NA, favoring decreased (increased) precipitation and increased (decreased) potential evapotranspiration over northern (southern) NA, finally contributing to the formation of EOF1. The second EOF (EOF2) shows an approximate zonal dipole pattern, which is influenced by the British–Baikal Corridor (BBC) and Scandinavia (SCA) teleconnection patterns. The positive BBC and SCA patterns can lead to an anomalous anticyclone over the Ural Mountains and a cyclone over Lake Baikal. Such atmospheric circulations result in a zonal dipole pattern in precipitation and potential evapotranspiration over NA through changing the local moisture condition, air temperature, and radiation, consequently favoring the formation of EOF2. Fitting analysis indicates that the aforementioned atmospheric factors can explain 76% (55%) of the interannual variability of EOF1 (EOF2).

Interdecadal change in the influence of the southern annular mode to the tropical cyclone frequency over the Bay of Bengal

AbstractThe current study investigates the modulation of the tropical cyclone (TC) frequency (TCF) over the Bay of Bengal (BoB) by the southern annular mode (SAM). The analysis reveals that the SAM–TCF relationship during October–November–December has undergone interdecadal changes from significant during 1971–1994 to insignificant during 1995–2021. This contrasting influence of the SAM on the TCF occurrence is also echoed in the large‐scale environmental variables conducive to forming tropical cyclones (TCs). Based on the possible mechanism, we found that the SAM can imprint tripole sea surface temperature (SST) patterns in the southern Indian Ocean via altering surface wind speed from 1971 to 1994. The SAM‐related tripole SST pattern induces the surface‐level anticyclone anomaly, which enhances the south easterlies towards the western equatorial Indian Ocean. Such intensified anomalous wind crosses the equator and diverts towards the east to form the cyclone anomaly in the BoB. Meanwhile, at 200 hPa, the anomalous anticyclone over western Australia induces divergent wind flows over the study region. Consequently, the ascending motion in BoB promotes the tropical cyclone generation. During 1995–2021, however, the SAM is associated with the dipole SST pattern in the southern Indian Ocean. Correspondingly, the SAM‐related dipole SST yields anomalous atmospheric circulations confined to the Southern Hemisphere and eventually fails to impact the formation of TCs in the northern Indian Ocean, where the study region is located. The findings of this research can be useful in advancing our knowledge of the interannual variability of TCs activity in the BoB based on the remote climate signal.

The Impact of Climate Change on Road Traffic Crashes in Ghana.

Despite the substantial injuries and fatalities from Road Traffic Crashes (RTCs), evidence of climate change's impact on RTCs in Ghana is lacking. This study assessed the impact of climate change on RTCs in Ghana by combining quantitative (Mann-Kendall trend tests, Continuous Wavelet Transform analysis, causal inference analysis) and qualitative (15 key stakeholder interviews) methods. The quantitative analysis employed monthly rainfall and temperature data (1991-2021) alongside RTC data (1998-2021) across 10 regions. While rainfall trends varied regionally, the wet season (April through mid-October) showed a strong link to crash severity for all regions across Ghana. Wavelet analysis showed higher crash severity in the wet season within every 2-8 months period in a particular annual year during the study period. Causal inference analysis revealed rainfall's stronger influence (3.59%) on fatal crashes during the wet season compared to temperature (0.04%). Key stakeholder interviews highlighted perceived changes in temperature and intense rainfall patterns affecting RTCs, especially during rainy seasons suggesting an association between increased rainfall and crash severity. These findings emphasize the multifaceted role of climate change on road safety and the need to address weather-specific risks.

The Impact of Climate Change on Solar Radiation and Photovoltaic Energy Yields in China

Solar photovoltaics is a direct use of solar resources to generate electricity, which is one of the most important renewable energy application approaches. Regional PV output could be affected by the regional patterns of temperature and irradiance, which are impacted by climate change. This study examines the impact of climate change on the energy yields from solar PV across China in the future under the medium-emission scenario (SSP245) and high-emission scenario (SSP585) by calculating PV potential using the data of solar radiation on a tilted surface and temperature. Generally, under the SSP245 scenario, solar radiation increased by 0.8% and 2.15%, and PV energy yields increased by 0.28% and 1.21% in 2020–2060 and 2061–2099, respectively; under the SSP585 scenario, solar radiation increased by 0.73% and 1.35%, and PV energy yields increased by 0.04% and −1.21% in 2020–2060 and 2061–2099, respectively. Under both scenarios, PV energy potential showed an obvious increase in southeast and central China and a significant decrease in northwest China, Tibet, and Inner Mongolia. Therefore, it is suggested that under the medium-emission scenario, climate change could increase the PV energy potential, while under the high-emission scenario, it could inhibit the PV energy potential in China.

Can urban shrinkage contribute to mitigating surface air temperature warming?

In recent years, urban areas are increasingly experiencing intense warming. Although urbanization is an important driver of warming in urban environments, it remains unclear whether depopulation trends in shrinking cities mitigate this warming effect. Here, we explored the relationship between shrinking cities and observed warming in China. Of the 356 Chinese cities, 95 were identified as shrinking between 2000 and 2010. We categorized 2419 observation stations into three groups—rural, shrinking, and non-shrinking—and generated a surface air temperature (SAT) anomaly series for each group from 1961 to 2014. Temperature differences between the shrinking and non-shrinking urban stations were investigated. Using segmented generalized least squares regression, the spatiotemporal temperature patterns across the mean (Tmean), maximum (Tmax), and minimum temperatures (Tmin), diurnal temperature range (DTR) indicators, and across seasons—spring, summer, autumn, and winter—were explored. Results revealed a cooling effect in shrinking cities, with decadal decreases of 0.042 °C (–0.078 to –0.005 °C), 0.083 °C (–0.126 to –0.039 °C), and 0.029 °C (–0.062 to –0.005 °C) in regional Tmean, Tmax, and Tmin anomalies, respectively. Moreover, pronounced seasonality was identified in this phenomenon—the cooling effect was most notable for Tmean in spring and Tmax in autumn, less significant in summer, and negligible in winter. These results suggested that the population decline in shrinking cities could alleviate regional warming, having implications that could influence urban planning and climate mitigation policies.

Infectious disease responses to human climate change adaptations.

Many recent studies have examined the impact of predicted changes in temperature and precipitation patterns on infectious diseases under different greenhouse gas emissions scenarios. But these emissions scenarios symbolize more than altered temperature and precipitation regimes; they also represent differing levels of change in energy, transportation, and food production at a global scale to reduce the effects of climate change. The ways humans respond to climate change, either through adaptation or mitigation, have underappreciated, yet hugely impactful effects on infectious disease transmission, often in complex and sometimes nonintuitive ways. Thus, in addition to investigating the direct effects of climate changes on infectious diseases, it is critical to consider how human preventative measures and adaptations to climate change will alter the environments and hosts that support pathogens. Here, we consider the ways that human responses to climate change will likely impact disease risk in both positive and negative ways. We evaluate the evidence for these impacts based on the available data, and identify research directions needed to address climate change while minimizing externalities associated with infectious disease, especially for vulnerable communities. We identify several different human adaptations to climate change that are likely to affect infectious disease risk independently of the effects of climate change itself. We categorize these changes into adaptation strategies to secure access to water, food, and shelter, and mitigation strategies to decrease greenhouse gas emissions. We recognize that adaptation strategies are more likely to have infectious disease consequences for under-resourced communities, and call attention to the need for socio-ecological studies to connect human behavioral responses to climate change and their impacts on infectious disease. Understanding these effects is crucial as climate change intensifies and the global community builds momentum to slow these changes and reduce their impacts on human health, economic productivity, and political stability.

Studies on Variation of Temperature and Rainfall using Climatological data for the Plain and Hill zones of Uttarakhand

The present study examines long-term annual, seasonal and monthly changes and short-term fluctuations in monsoonal rainfall and temperature over plain and hill zones of Uttarakhand. Both rainfall and temperature data for period of 1981-2020 were analyzed in this study. Statistical trend analysis techniques namely Mann–Kendall test and Sen’s slope estimator were used to examine and analyze the problems. The detailed analysis of the data for 40 years indicates that the annual range of temperature is increasing in the hill zone. In the context of agriculture, the observed trends in temperature and rainfall patterns pose significant implications for farming practices and crop yields in Uttarakhand. The increasing annual range of temperature, particularly in the hill zone, suggests a heightened risk of temperature extremes such as heat waves and cold spells. During the monsoon season, while rainfall levels may remain relatively stable or exhibit minor fluctuations, the variability highlighted by the box and whisker plots underscores the importance of preparedness for both excess and deficit rainfall scenarios.

Feedbacks, Pattern Effects, and Efficacies in a Large Ensemble of HadGEM3‐GC3.1‐LL Historical Simulations

AbstractClimate feedbacks over the historical period (here defined as 1850–2014) have been investigated in large ensembles of historical and single forcing experiments (hist‐ghg, hist‐aer, and hist‐nat), with 47 members for each experiment. Across the historical ensemble with all forcings, a range in estimated Effective Climate Sensitivity (EffCS) between approximately 3–6 K is found, a considerable spread stemming solely from initial condition uncertainty. The spread in EffCS is associated with varying Sea Surface Temperature (SST) patterns seen across the ensemble due to their influence on different feedback processes. For example, the level of polar amplification is strongly correlated with the amount of sea ice melt per degree of global warming. This mechanism is related to the large spread in shortwave clear‐sky feedbacks and is the main contributor to the different forcing efficacies seen across the different forcing agents, although in HadGEM3‐GC3.1‐LL these differences in forcing efficacy are shown to be small. The spread in other feedbacks is also investigated, with the level of tropical SST warming strongly correlated with the longwave clear‐sky feedbacks, and the local surface‐air‐temperatures well correlated with the spread in cloud radiative effect feedbacks. The metrics used to understand the spread in feedbacks can also help to explain the disparity between feedbacks seen in the historical experiment simulations and modeled estimate of the feedbacks seen in the real world derived from an atmosphere‐only experiment prescribed with observed SSTs (termed amip‐piForcing).

Unravelling spatiotemporal patterns in global sea surface temperatures with dynamic mode decomposition

AbstractExtracting global sea surface temperature (SST) patterns is essential for understanding climate variability in both regional and global perspective. Traditional methods, limited by assumptions of orthogonality, hinder our ability to fully capture the dynamics of global SST, particularly in the complex Pacific basin. This study introduces dynamic mode decomposition (DMD), a powerful method from fluid dynamics, to extract global SST patterns since 1900. Our analysis shows that DMD successfully captures well‐known patterns like global warming and the Atlantic Multidecadal Oscillation (AMO). More importantly, it reveals three Pacific SST modes that are spatially non‐orthogonal but exhibit distinct characteristics. Spectral analysis shows that these Pacific modes have distinct periodicities: Pacific Multi‐decadal Mode (PMDM, ~50 years), Quasi‐decadal Mode (PQDM, 8–16 years) and Interannual Mode (PIAM, 2–8 years). This highlights DMD's strength in not only capturing known patterns but also separating modes with similar spatial features but unique dynamics. Further analysis reveals significant differences in their impacts on global air temperature. During positive phases, all three modes induce tropical warming, with PIAM exerting the strongest influence and PMDM the weakest. In the Northern Hemisphere, both PQDM and PIAM drive mid‐latitude cooling and high‐latitude warming, with a more pronounced effect from PQDM. PMDM, in contrast, triggers widespread cooling across the Northern extratropics. In the Southern Hemisphere, PMDM's influence on temperature exhibits a distinct latitudinal banding pattern. PIAM and PQDM, on the other hand, exhibit a regionalized impact, primarily concentrated in the Amundsen and Ross Seas, with PQDM's influence extending to the Antarctic continent.

What Determines the East Asian Winter Temperature during El Niño?—Role of the Early Onset El Niño and Tropical Indian Ocean Warming

Abstract Atmospheric teleconnections from the Pacific El Niño are key to determining the East Asian winter climate. Using the database for policy decision-making for future climate change (d4PDF) large-ensemble simulations, the present study investigates a mechanism for the warm and cold East Asian winters during El Niño with a focus on atmospheric teleconnections triggered by anomalous sea surface temperature (SST) patterns in the tropical Indo-Pacific. Our results show that the western Pacific (WP) teleconnection pattern plays a primary role in the warm winters in East Asia. The WP pattern tends to appear in years when both an early El Niño and the positive phase of the Indian Ocean dipole (IOD) mode develop in boreal autumn. In those years, the tropical Indian Ocean (TIO) strongly warms in the following winter, forming a distinct zonal contrast in precipitation anomalies over the tropical Indo-Pacific through a reduced Walker circulation. The Rossby wave source anomalies indicate that the WP pattern is associated with the weakened Indo-Pacific Walker circulation. By contrast, the WP pattern does not dominate in the cold winters due to the absence of strong TIO warming. The present study proposes a mechanism that promotes the excitation of the WP pattern through the upper-troposphere divergence in East Asia associated with the Walker circulation modulated by the tropical Indo-Pacific interbasin interaction. Significance Statement The East Asian winter temperature variability is controlled not only by the strong atmospheric internal variability in the midlatitudes and high latitudes but also by remote forcing from the tropical ocean. Our study investigates how El Niño exerts diverse impacts on the East Asian winter temperature, depending on where atmospheric convection intensifies in the tropical Pacific Ocean and the Indian Ocean. Our results show that an intense warming of the tropical Indian Ocean and the early development of El Niño are the major factors for warm winters in East Asia. Given that a precursor of the intense Indian Ocean warming appears in boreal autumn, our findings should contribute to the improvement of seasonal prediction for the East Asian winter climate.

The Impact of Model Horizontal Resolution on Simulating Regional Climate Over East Asia Using Variable‐Resolution CESM2

AbstractIn this study, a variable‐resolution version of the Community Earth System Model (VR‐CESM) with mesh refinement (∼0.125°) over East Asia is used to simulate the regional climate in this region. For the evaluation of model performance and sensitivity to model resolution, the simulated near‐surface temperature and precipitation are compared with observations and simulation results from a globally quasi‐uniform (∼1°) CESM (UN‐CESM). Results show that VR‐CESM better simulates the spatial patterns and seasonal variations of mean temperature and precipitation than UN‐CESM over China. For extreme events, VR‐CESM improves the simulation of the occurrence frequency of wintertime daily minimum temperature and heavy precipitation. In regions with complex terrains, VR‐CESM better resolves the topographic forcing and captures the observed fine‐scale spatial patterns of temperature and precipitation, although precipitation is still overestimated. For East Asian summer monsoon precipitation, both UN‐CESM and VR‐CESM tend to overestimate (underestimate) the precipitation over northern (southern) China, which is associated with too strong meridional water vapor transport in the models and biases in the large‐scale circulation in the middle and upper troposphere. Different from previous studies with different physics parameterizations and refined domains, as the model resolution increases, simulated monsoon precipitation evolution is not obviously improved, and convective precipitation intensity decreases over eastern China. Despite this, our results indicate that VR‐CESM simulates regional climate, topographical forcing, and large‐scale circulations over East Asia reasonably well, and thus it can be applied for the future climate projection in the region.

An extraordinary jewel beetle species (Perotis unicolor (Olivier, 1790)) from Northeastern Algeria: re-discovery of this species in North Africa after more than half a century

Jewel beetles (Buprestidae), also known as metallic wood-boring beetles, predominantly inhabit forest environments. Several taxa within this family hold heritage status in both broadleaf and conifer forests. The larvae of most species undergo development within the inner, living part of tree bark, while some species can behave as opportunistic pests, causing considerable damage to weakened host trees. Notably, in Algeria, Lamprodila festiva on Barbary thuja (Tetraclinis articulata), and Agrilus biguttatus on oak trees were recognized as significant pests. Given the potential impact of climate change on forest jewel beetles, there were two key concerns: i) many of these species prefer warmer climates, making them thermophilic, and shifts in temperature patterns can affect their distribution and abundance, ii) following severe droughts, forest declines and diebacks may occur, offering an opportunity for these beetles to exploit weakened trees. In the context of this study, a Buprestidae (Coleoptera) species was re-discovered in the northeastern region of Algeria within holm oak (Quercus ilex) shrub lands, Perotis unicolor (Olivier, 1790). This is an important finding as it has not been reported in the fauna of North Africa for more than half a century.

A Review on Global Warming

One of the most important environmental issues of our time is global warming, which is primarily caused by human activity. In order to provide a thorough examination of the phenomenon, this review paper will cover its fundamental causes, observed and anticipated effects on the Earth's climate and ecosystems, as well as proposed mitigating measures. The atmospheric emission of greenhouse gases, particularly carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), is the main cause of global warming. The remarkable rise in greenhouse gas concentrations during the past century has been mostly attributed to the burning of fossil fuels, deforestation, industrial operations, and agricultural activities. The effects of global warming are numerous and extensive. Increasing temperatures have sped up the melting of glaciers and polar ice caps, which has raised sea levels and increased the likelihood of coastal flooding. Extreme weather occurrences, such as heatwaves, droughts, and violent storms, have increased in frequency and have a negative effect on agriculture, water supplies, and vulnerable communities. Additionally, as ecosystems experience extraordinary shifts in temperature and precipitation patterns, biodiversity loss and ecosystem disruption are being seen. This paper presents a variety of potential mitigation tactics that could be used to alleviate the problems caused by global warming. Among these include switching to renewable energy sources, improving energy efficiency, putting reforestation and afforestation programmes into action, and applying sustainable agriculture methods. Additionally, international collaboration and policy frameworks are essential for promoting group initiatives. With significant effects on the environment and society, global warming continues to be a top priority. On a local, national, and international level, cooperation is required to address this complicated issue. This review emphasises how crucial it is to comprehend the underlying causes, effects, and mitigation strategies in order to effectively combat global warming and build a sustainable future for future generations

Soret Effect of Unsteady Parabolic Flow Past an Accelerated Vertical Plate with Constant Temperature and Mass Diffusion in t he Presence of Rotation

Objective: Circular force's detrimental effects on inhomogeneous parabola circulation over an upright slab that rapidly accelerates in uniform temperature and continuous mass dispersion are discussed. There is no electrical conductivity in the liquid in question. Methods: The solutions for the temperature, concentration, and velocity profiles were identified through the Laplace transformation methodology. Findings: Graphical drawings displaying several specifications, include the acceleration parameter, Schmidt value, Soret value, Hartmann number, thermal Grashof number are used to illustrate the results that were obtained. It is noted that as the values - thermal Grashof number -increase, speed also increases. Regarding Schmidt and Prandtl numbers, the tendency is the opposite. Novelty: The unique aspect of this work is its thorough analysis of the Soret Effect in an erratic, rotating, parabolic flow past an accelerating vertical plate with mass diffusion and constant heat. The work closes gap in the literature by addressing these particular conditions and offers insightful conclusions and useful techniques that may be used to a variety of scientific and engineering issues. This study investigates the impact of rotating effects and Soret impact on erratic convective movement in a vertical plate. Results show that Schmidt number and wall thickness increase over time, while temperature patterns rise with increasing Sr and Sc levels. The Prandtl number depends on air and water temperatures. The study fills a literature gap and provides valuable insights for various scientific and practical applications. Keywords: Soret effect, Turning, Mass dissemination, Parabolic, Vertical surface

Effects of climate change on the availability of non-timber forest products (NTFPs) in the Kavonge and Museve hilltop forests in Kenya

The study evaluated the effects of climate change on the availability of NTFPS in Kavonge and Museve hilltop forests in Kitui County, Kenya. The specific study objective was to assess local community perception on rainfall and temperature patterns on NTFPs availability. A sample size of 120 respondents were selected for the study using the Yamane formula. A purposive sampling method was used to select villages within 5 kilometer radius to both hilltop forests and a systematic transect line design of 1km by 1km was used to select households for data collections. Data were collected by employing structured questionnaires, key informant interviews and focus groups discussions. The data was analyzed using descriptive statistics (frequencies, percentages, bar charts), chi-square test and logistic regression. The result revealed that majority 83.0% of respondents strongly agreed that climatic conditions of the area has changed. The results submit that 96% of the respondents perceived an increase in temperature pattern during this recent period of 2018-2023 while, 100% perceived a decrease in rainfall pattern during this recent period of 2018-2023. The logistic regression model results revealed that, age, education, occupation and residency period significantly (p < 0.05) influenced community perception of climate change (rainfall and temperature) patterns on NTFPs availability in the study area. It is ascertained that the Kavonge and Museve forests edge communities still rely on the available NTFPs as a safety net when faced with unfavorable circumstances, such as crop failure due to climate change. However, it was reported that the available quantities of NTFP are declining due to climate change. I conclude that, available NTFPs will continue to decrease if stringent sustainable utilization and management measures are not implemented.

Comparative study between observed and numerical downscaled data of surface air temperature

Surface Air temperature, being one of the key parameters of climate, plays an important role in occurrence severe environmental issues like droughts, floods, rate of evaporation etc. In this study, an endeavor has been made to investigate the experiments available in Educational Global Climate Model (EdGCM) at Sylhet Agricultural University for recognizing best suited experiment to predict the changing pattern of surface air temperature at Sylhet region. Downscaling is a cutting-edge procedure to produce high-goals atmosphere change expectation from coarse to fine goals of worldwide atmosphere model outcomes and a conspicuous device for estimating future atmosphere situation at the local scale for some information alarm zone like Bangladesh. Maps are generated from EdGCM simulation run to collect data and depict global temperature variations. Transform software have been connected to downscale the outcomes of temperature data by Doubled_CO2, Global_Warming_01, Ice_Age_21kya, IPCC_A1F1_CO2, Modern_PredictedSST and Modern_SpecifiedSST. The trend analysis was performed using the Mann-Kendall Trend test and Sen-slope estimator. Temperature changes are significant for observed results, Doubled_CO2 and IPCC_A1F1_CO2 results where p-value is less than alpha 0.05. Doubled_CO2 results are more suited for dry season and IPCC_A1F1_CO2 provides better results for monsoon. The investigation could have been unquestionably progressively broad in the event that more situations of EdGCM information were utilized, and local boundary conditions were used.

Gendered Impact of Climate Change among Paddy Farmers of Kahama District, Shinyanga Region, Tanzania

The study presents the findings on the research which examined gendered impacts of climate change among the paddy farmers of Kahama District, Shinyanga Region. Specifically, the study assessed gendered desegregated effects of climate change among the paddy farmers and the implications on the effects of climate change among women farmers of Kahama District. The study adopted a cross sectional research design on which 312 randomly selected farm households were interviewed. The study employed a triangulation approach whereby primary data were collected through household surveys, field observation and key informants’ interviews. The findings revealed that women and men farmers disproportionally affected by climate change. These effects include the prevalence pests and diseases over a period of 30 years and the general decrease in crop yields to due to the changes in temperature and rainfall patterns. These effects pose negative implications in increasing women’s workload and time burden, health and safety risks, and livelihood and food security respectively. The study concluded that women bear a disproportionate burden of the challenges of climate change due to existing social and economic inequalities. This negatively subject women farmers into health, livelihoods and overall additional household burden of the households’ activities. The study recommends to the Government to enforce gender-sensitive policies and interventions. Furthermore, it is recommended to the Government to ensure that effective strategies prioritize gender equity and inclusivity so as to build a more adaptive farming community.

Flow and heat transfer characteristics of offset unsubmerged jets impinging on rotating disks

A study of an unsubmerged jet impinging on a heated rotating disk is conducted to investigate the multi-phase flow dynamics and heat transfer characteristics. The effects of varying the disk rotational speeds, ranging from 240 to 16,000 revolutions per minute, and the jet location, ranging from a symmetrical condition to offset conditions up to 80 % of the disk radius, are analysed. The jet nozzle diameter and the ratio of the jet impingement distance to nozzle diameter are held constant at 4 mm and 10, respectively. The Volume of Fluid method is employed to model the two-phase flow, with a conjugate heat transfer boundary condition applied at the fluid–solid interface. A moving mesh rotation model is employed for the computations. The results show that changes in jet offset positions at different rotational speeds lead to distinct flow and temperature patterns, significantly impacting the heat transfer on the top surface of the rotating disk. With decreasing jet offset distances, better overall heat transfer performance and lower surface average temperatures are obtained. While increasing rotational speed up to 1930 revolutions per minute at a high jet offset (0.6) enhanced the average Nusselt number by 50 %, at very high speeds (16,000 revolutions per minute), low film thickness or poor oil contact with the hot surface reduced heat transfer performance to 3 %. Consequently, maximum average Nusselt numbers are achieved at mid rotational speeds (1930 revolutions per minute) and small jet offsets (less than 0.4). Poor heat transfer performance was observed at higher speeds (above 1930 revolutions per minute) and larger offsets (above 0.4). A new correlation is proposed for the average heat transfer based on the rotational Reynolds number and jet offset location.

Adapting pest management strategies to changing climates for the redlegged earth mite, Halotydeus destructor

As climate change continues to modify temperature and rainfall patterns, risks from pests and diseases may vary as shifting temperature and moisture conditions affect the life history, activity, and distribution of invertebrates and diseases. The potential consequences of changing climate on pest management strategies must be understood for control measures to adapt to new environmental conditions. The redlegged earth mite (RLEM; Halotydeus destructor [Tucker]) is a major economic pest that attacks pastures and grain crops across southern Australia and is typically controlled by pesticides. TIMERITE® is a management strategy that relies on estimating the optimal timing (the TIMERITE® date) for effective chemical control of RLEM populations in spring. In this study, we assessed the efficacy of control at the TIMERITE® date from 1990 to 2020 across southern Australia using a simulation approach that incorporates historical climatic data and field experimental data on life history, seasonal abundance, and population level pesticide responses. We demonstrate that moisture and temperature conditions affect the life history of RLEM and that changes in the past three decades have gradually diminished the efficacy of the TIMERITE® strategy. Furthermore, we show that by incorporating improved climatic data into predictions and shifting the timing of control to earlier in the year, control outcomes can be improved and are more stable across changing climates. This research emphasises the importance of accounting for dynamic environmental responses when developing and implementing pest management strategies to ensure their long-term effectiveness. Suggested modifications to estimating the TIMERITE® date will help farmers maintain RLEM control outcomes amidst increasingly variable climatic conditions.

Analysis of Spatial and Temporal Variations in Evapotranspiration and Its Driving Factors Based on Multi-Source Remote Sensing Data: A Case Study of the Heihe River Basin

The validation of remotely sensed evapotranspiration (ET) products is important for the development of ET estimation models and the accuracy of the scientific application of the products. In this study, different ET products such as HiTLL, MOD16A2, ETMonitor, and SoGAE were compared using multi-source remote sensing data and ground-based data to evaluate their applicability in the Heihe River Basin (HRB) during 2010–2019. The results of the comparison with the site observations show that ETMonitor provides a more stable and reliable estimation of ET than the other three products. The ET exhibited significant variations over the decade, characterized by a general increase in rates across the HRB. These changes were markedly influenced by variations in land use and topographical features. Specifically, the analysis showed that farmland and forested areas had higher ET rates due to greater vegetation cover and moisture availability, while grasslands and water bodies demonstrated lower ET rates, reflecting their respective land cover characteristics. This study further explored the influence of various factors on ET, including land use changes, NDVI, temperature, and precipitation. It was found that changes in land use, such as increases in agricultural areas or reforestation efforts, directly influenced ET rates. Moreover, meteorological conditions such as temperature and precipitation patterns also played crucial roles, with warmer temperatures and higher precipitation correlating with increased ET. This study highlights the significant impact of land use and climatic factors on spatiotemporal variations in ET within the HRB, underscoring its importance for optimizing water resource management and land use planning in arid regions.