Changes In Air Temperature Research Articles

ЖАЙЫҚ ӨЗЕНІНДЕГІ МҰЗ ҚҰБЫЛЫСТАРЫ МЕН МЕТЕОЭЛЕМЕНТТЕРДІҢ КӨПЖЫЛДЫҚ ӨЗГЕРІСІН БАҒАЛАУ

This article examines the changes in ice phenomena and meteorological parameters of the Zhaiyk River during the period from 1936 to 2021. The changes in ice phenomena observed over many years along the Zhaiyk River were analyzed. For this, long-term data on the start and end of ice phenomena at various stations along the river were used. As a result, it was established that the formation of ice on the river has shifted to later dates, the clearing of the river from ice has shifted to earlier dates, and the duration of the ice cover has decreased. The Mann-Kendall test and the Sen’s Slope method were used to assess the changes in long-term average air temperatures in the region. As a result, it was determined that the annual air temperature increase is within the range of 0,032...0,035. Additionally, changes in long-term values of temperature and precipitation, as well as their impact on river discharge, were analyzed. The study results show that global and local climate changes have a significant impact on ice phenomena and the hydrological characteristics of the Zhaiyk River.

Increased vulnerability of Arctic potential ice roads under climate change

Temporary ice roads built by the process of snow compaction, watering, and icing during cold winters are lifelines for land access in remote Arctic. In the context of the Arctic amplified warming, the vulnerability of potential ice roads under the influence of complex climate system remains unclear. Here, we construct a potential ice road assessment model that allows quantization of the climatic suitability of potential ice roads in the Arctic. Using satellite remote sensing and meteorological data, we find changes in surface air temperature and snow cover reduced the climatic suitability of potential ice roads during 1979–2017. Spatially, potential ice roads in North America face more immediate threats due to decreased snow depth compared to Eurasia. Before the end of the 21st century, we project a further decline in the climatic suitability of potential ice roads, primarily due to increasing surface air temperatures and decreasing permafrost stability. Taking precious metal/diamond exploration as an example, we conclude that mining activities associated with ice roads will face access difficulties by 2050–2100 due to the decreased potential ice roads. These results give new insights into the challenges and opportunities of Arctic overland travel.

Emergent constraints on global soil moisture projections under climate change

Surface soil moisture is projected to decrease under global warming. Such projections are mostly based on climate models, which show large uncertainty (i.e., inter-model spread) partly due to inadequate observational constraint. Here we identify strong physically-based emergent relationships between soil moisture change (2070–2099 minus 1980–2014) and recent air temperature and precipitation trends across an ensemble of climate models. We extend the commonly used univariate Emergent Constraints to a bivariate method and use observed temperature and precipitation trends to constrain global soil moisture changes. Our results show that the bivariate emergent constraints can reduce soil moisture change uncertainty by 7.87%, which is four times more effective than traditional temperature-based univariate constraints. The bivariate emergent constraints change the sign of soil moisture change from negative to positive for semi-arid, dry sub-humid and humid regions and global land as a whole, but exacerbates the drying trend in arid and hyper-arid regions.

Precession Controls on Climate and Water Isotope Signals in Northern Africa

AbstractPrecessional forcing is a key driver of quaternary climate change. Based on 24 experiments covering a full precession cycle, this study explores spatio‐temporal variations of both climate and isotope signals in Northern Africa. We find a synchronous phasing of precipitation variations with solar radiation levels and an asynchronous timing of surface air temperature changes across different sub‐regions of Northern Africa. Based on daily precipitation, our results reveal earlier onset and withdrawal, as well as a shorter duration of the West Africa summer monsoon (WASM) at minimum precession compared to maximum precession. The onset of the WASM is controlled by the intensity of the Sahara Heat Low, while the monsoon termination is linked to subtropical solar radiation and interhemispheric thermo contrast. Using a novel scale‐flux tracing technique, we find that, precipitation during minimum precession is more influenced by evaporation from warmer and more humid regions compared to maximum precession. Additionally, certain inland areas of Northern Africa exhibit positive temporal isotope‐precipitation gradients, violating the “amount effect.” This phenomenon mainly occurs during precession phases associated with Green Sahara periods. The isotope composition changes in such places primarily reflect changes in upstream rainfall quantity, rather than changes in local precipitation as is inferred from present day analogs. Conversely, the “amount effect” remains applicable during dry periods in Africa when the Sahara desert is present. This suggests that isotope‐based reconstruction of past precipitation variations during Green Sahara periods over Northern Africa needs to be taken with caution.

ASSESSMENT OF NATURAL MOISTURE CONDITIONS ON THE EXAMPLE OF THE SOUTHWESTERN PART OF KYIV REGION

The sustainability of agriculture in Ukraine directly depends on the level of natural soil moisture supply, which is significantly deteriorating under the influence of climate change. The article investigates the impact of these changes on the value of potential evapotranspiration (ETo) in the southwestern part of the Kyiv region (Central Forest-Steppe of Ukraine) based on the data from the Bila Tserkva weather station for the period from 1991 to 2020. The research methodology is based on the assumption that the assessment of the impact of climate change on the state of natural moisture supply can be performed provided that climate change itself is assessed according to the long-term dynamics of air temperature and precipitation in the period from 1991 to 2021 with the values of the same indicators in the period from 1961 to 1990 - the climatic norm. The potential evapotranspiration (ETo) was chosen as the criteria for assessing the impact of climate change on the state of soil moisture supply. The assessment results showed that the annual value of potential ETo increased by 9%, which may indirectly indicate a deterioration in the conditions of natural soil moisture supply. This has important implications for agriculture, as an increase in ET can lead to a decrease in available moisture for plants, which will negatively affect crop yields. The study covers changes in average annual and average monthly air temperature, as well as precipitation by season and month. It has been established that over the past thirty years, Ukraine has been experiencing a deterioration in moisture conditions, which requires the adaptation of agricultural practices. Sustainable development of the agricultural sector is possible only if changes in the natural moisture supply are taken into account when developing management models and cultivation technologies. The results obtained indicate the need to introduce innovative agronomic technologies that adapt to current climate change.

A Shoot Phenological Study of Certain Phyllostachys Bamboo Taxa Under Central European Climatic Conditions.

This study aimed to understand the phenological changes in the shoots of temperate bamboo Phyllostachys spp. grown in Hungary, with a focus on how these changes were influenced by local climatic conditions. Data collected over two years on shoot phenology were analyzed with weather variables, especially air temperature and soil temperature. Shoot emergence date, shoot numbers, and shooting period were recorded within and between Phyllostachys spp. The date of shooting was observed between May and July, and species started shooting in May the most, followed by June. Only one species, P. sulphurea, started shoot emergence in July. Shoot emergence started earlier in 2022 than in 2023 and ranged from 3 days to 27 days. Bamboo shoot phenology was strongly influenced by the air temperature and soil temperature each year. According to our regression analysis, the dates of shoot emergence were influenced by air temperature (r2 = 0.819) in 2022 and 2023 (r2 = 0.781), and soil temperature also influenced shoot emergence (r2 = 0.956) in 2022 and 2023 (r2 = 0.769). Sharp air temperature changes between the shooting season and the period before shooting were considered as the reasons for early shooting. The soil temperature in April before the start of shoot emergence was 8.15 °C, increasing to 14.1 °C during shooting time in May. Abrupt fluctuations of air temperature between the shoot emergence season and the month prior to shooting commencement determined early shooting or late shooting. The soil temperature had to reach 9 °C or above prior to shooting time, as this was found to be a critical temperature for shoot emergence in Phyllostachys bamboo taxa.

Terrestrial evidence for volcanogenic sulfate-driven cooling event ~30 kyr before the Cretaceous-Paleogene mass extinction.

Alongside the Chicxulub meteorite impact, Deccan volcanism is considered a primary trigger for the Cretaceous-Paleogene (K-Pg) mass extinction. Models suggest that volcanic outgassing of carbon and sulfur-potent environmental stressors-drove global temperature change, but the relative timing, duration, and magnitude of such change remains uncertain. Here, we use the organic paleothermometer MBT'5me and the carbon-isotope composition of two K-Pg-spanning lignites from the western Unites States, to test models of volcanogenic air temperature change in the ~100 kyr before the mass extinction. Our records show long-term warming of ~3°C, probably driven by Deccan CO2 emissions, and reveal a transient (<10 kyr) ~5°C cooling event, coinciding with the peak of the Poladpur "pulse" of Deccan eruption ~30 kyr before the K-Pg boundary. This cooling was likely caused by the aerosolization of volcanogenic sulfur. Temperatures returned to pre-event values before the mass extinction, suggesting that, from the terrestrial perspective, volcanogenic climate change was not the primary cause of K-Pg extinction.

Observation-Constrained Climate Change in China over 1850–2014 by Aerosols in CMIP6 Models

Abstract Aerosols play a very important role in climate change with large uncertainties. Using the multimodel results from CMIP6, we analyzed the aerosol effective radiative forcing (ERF) and aerosol-induced surface air temperature (SAT) change in China in the present day (PD; 11-yr mean of 2004–14) relative to the preindustrial (PI) time (11-yr mean of 1850–60). With the increase in the anthropogenic emissions, the simulated surface PM2.5 concentration and aerosol optical depth (AOD) averaged over eastern China (EC; 18°–44°N, 103°–122°E) increased by 21.43 ± 7.58 μg m−3 and 0.47 ± 0.33, respectively, from PI to PD. The simulated aerosol ERFs in EC were −4.91 ± 2.56 and −5.35 ± 2.40 W m−2 from equilibrium and transient simulations, respectively. The simulated change in SAT caused by the increases in aerosols was −1.37° ± 0.38°C in EC from PI to PD. The simulated values of equilibrium and transient climate sensitivity to aerosols (CSA; aerosol-induced SAT change per unit aerosol ERF) in EC were 0.236° and 0.222°C (W m−2)−1, respectively. By using the observed AOD from MODIS to constrain aerosol ERF, the constrained aerosol equilibrium and transient ERFs over EC were −4.66 and −4.93 W m−2, respectively, which were smaller in magnitude than the simulated values directly from the models. By using the observed SAT from the Climatic Research Unit temperature version 5 to constrain aerosol-induced cooling, the surface cooling caused by aerosols was magnified to −1.47°C. The adjusted CSA after the constraint was calculated by dividing adjusted aerosol-induced SAT change by adjusted aerosol ERF. Adjusted equilibrium and transient CSA values in EC were 0.32° and 0.34°C (W m−2)−1, respectively.

Runoff Characteristics and Their Response to Meteorological Condition in the Yarlung Zangbo River Basin: Spatial Heterogeneity Due to the Glacier Coverage Difference

The Yarlung Zangbo River (YZR) is a sizeable highland river on the Tibetan Plateau, and its runoff process is crucial for understanding regional water resource features and related ecological patterns. However, the runoff characteristics of the YZR Basin (YZRB) remain unclear, especially how it would react to climate change. This study comprehensively analyzed the runoff characteristics of the entire YZRB based on a validated distributed hydrological model (SWAT) coupled with a glacier module (SWAT-glac), identified the runoff components, and explored the climate–discharge relationship, with a particular focus on the relationships between glacier runoff and changes in precipitation and air temperature. The results indicate that the SWAT-glac model, with localized glacier parameters, accurately simulates the runoff processes due to regional differences in meteorological conditions and uneven glacier distribution. Summer runoff dominates the basin, contributing 46.2% to 57.9% of the total, while spring runoff is notably higher in the downstream sections than in other areas. Runoff components vary significantly across river sections; precipitation is the primary contributor to basin-wide runoff (23.4–59.5%), while glacier runoff contribution can reach up to 54.8% in downstream areas. The study found that underlying surface conditions, particularly glacier coverage, significantly influence runoff responses to meteorological changes. The correlation between runoff and precipitation is stronger at stations where rainfall predominates, whereas runoff shows greater sensitivity to air temperature in glacier-covered areas. These findings enhance the understanding of runoff processes in the YZRB and offer valuable insights for the sustainable management of water resources in similar basins under climate change.

Analysis of air temperature change trends and their impacts in Australia

Global climate change has become a major challenge of our time, affecting ecosystems, weather patterns, and human activities across the globe. In this paper, we analyze the causes and effects of climate change by looking at Australia, in particular, summer temperature trends in the Melbourne region over the past 20 years. By examining historical data and considering the current situation, this paper makes recommendations to address these challenges. The relevant data shows a general increase in average summer temperatures in Melbourne and across Australia from 2003 to 2023. The main factors contributing to these fluctuations include global climate change, human activity, and urbanization. Continued temperature increases are primarily caused by global warming, exacerbated by increased greenhouse gas emissions from human activities and the urban heat island effect. The impacts of climate change on Melbourne and Australia are multifaceted, affecting public health, water management, energy demand, ecosystems, and agriculture. After analyzing Australia's overall climate, this paper proposes measures to improve it, such as reducing greenhouse gas emissions, increasing urban resilience, improving public health security, protecting and restoring ecosystems, and promoting scientific research and education.

The relationship of long-term changes in air temperature in the Arctic with fluctuations in hydrometeorological and astrogeophysical factors

The relationship of long-term changes in air temperature in the Arctic with fluctuations in hydrometeorological and astrogeophysical factors

Unraveling the Relationships between Trend of Dam Inflows, Hydrometeorological Variables, and Vegetation in Western and Southwestern United States

Abstract This paper explored temporal changes in magnitude and seasonality of low, median, and high inflows of 51 dams across the western and southwestern United States over the 1993–2022 period. Changes in precipitation, air temperature (an indicator of snowpack and evaporation), soil moisture, and vegetation were also examined to identify potential reasons for the temporal trends in dam inflows. Using monotonic and nonmonotonic tests, we found a general downward trend in dam inflows, particularly across the Upper Colorado and California regions. More than 30% of the dams showed a downward trend in their annual median inflows, high inflows during spring, and median inflows during fall. The downward trend of dam inflows was associated with decreasing precipitation and soil moisture and increasing temperatures. While vegetation exhibited positive associations with inflows, it did not seem to be a primary factor for explaining the inflow trends. We also observed shifts in the seasonality of low and high inflows; there was an increase in the proportion of inflows occurring during summer and fall and a decrease in winter proportions for low inflows. Similarly, high inflows exhibited an increase in spring proportions and a decrease in fall proportions. Our changepoint analyses detected nonmonotonic trends between 2002 and 2012 in ∼13% of the dams; the majority were located in the Upper Colorado and California regions. More than half of these changepoints were in 2011, likely due to widespread droughts then. Our study has implications for reservoir managers to identify changes that dams experience over time and assist them in proposing actions that maintain the dams’ functionality.

Public Perception of Climate Change Impact on Living Conditions in a Cold Region (the case of the Republic of Sakha (Yakutia))

Based on the materials of a sociological study conducted in August-October 2023, the characteristics of the perception by residents of the Republic of Sakha (Yakutia) of changes in the local climate and natural environment are analyzed. Residents of the republic notice significant changes in the climate, such as shifts in the onset of seasons, changes in air temperature, precipitation levels, and windiness. The population is concerned about the increasing frequency and intensity of natural phenomena caused by climate change: wildfires, thawing permafrost, destruction of roads, increasing number of mosquitoes in summer and an increasing incidence of acute respiratory viral infections and influenza, ice on roads in winter. Local residents also notice appearance of new species of birds, insects, plants, animals and fish not typical for the region. Negative assessments of the impact of climate change on traditional agriculture in Yakutia predominate.

Spatio-Temporal Variability of Water Temperature of Arctic Rivers in Russia over the Past 60 Years

This article presents the findings of a comprehensive statistical analysis based on one of the largest and most up-to-date datasets on average monthly water temperatures at 286 hydrological stations from 1961 to 2021. Through this analysis, a detailed examination of the factors influencing temperature formation in different landscape-diverse regions in the Russian Arctic has been conducted. It has been determined that air temperature plays a crucial role in determining water temperature, although its influence is constrained by geographical factors, primarily geographical latitude. An analysis of discontinuities in uniformity and the presence of trends was carried out, along with a regression analysis of the relationships between air and water temperatures. The results of estimating changes in river water temperature were simultaneously compared both with respect to generally accepted climatic periods (1961–1990 and 1991–2020) and with respect to revealed change point years. The results of the statistical analysis indicate a relatively slow increase in water temperature in the Arctic rivers of Russia over the past 60 years, by 0.11–0.74 K/decade. These changes are mainly due to changes in air temperature (about 70% of cases), which in turn are influenced by the altitude of the location of the objects and other local factors.

Projections of Climate Change Impact on Stream Temperature: A National-Scale Assessment for Poland

This national-scale assessment explores the anticipated impact of climate change on stream temperature in Poland. Utilizing an ensemble of six EURO-CORDEX projections (2006 to 2100) under Representative Concentration Pathways (RCPs) 4.5 and 8.5, the study employs the Soil and Water Assessment Tool (SWAT) to simulate stream temperature regimes. Validation against observed stream temperatures at 369 monitoring points demonstrates the reliability and accuracy of the SWAT model performance. Projected changes in air temperature reveal distinct seasonal variations and emission scenario dependencies. The validated stream temperature model indicates a uniform warming tendency across Poland, emphasizing the widespread nature of climate change impacts on aquatic ecosystems. Results show an increase in country-averaged stream temperature from the baseline (16.1 °C), with a rise of 0.5 °C in the near future (NF) and a further increase by 1 °C in the far future (FF) under RCP4.5. Under RCP8.5, the increase is more pronounced, reaching 1 °C in the NF and a substantial 2.6 °C in the FF. These findings offer essential insights for environmental management, emphasizing the need for adaptive strategies to mitigate adverse effects on freshwater ecosystems. However, as a preliminary study, this work uses a simplified temperature model that does not account for detailed hydrological processes and spatial variability, making it a good starting point for more detailed future research.

Extreme ultra-short-term changes in air temperature in January in southern Poland (the example of Sosnowiec) against the background of atmospheric circulation conditions

Large short-term changes in air temperature affect the functioning of living organisms in the environment and human activities. For this reason, a study of extreme positive and negative 10 min temperature changes and their causes related to atmospheric circulation was undertaken. Air temperature data for January in the period 2001–2017 in southern Poland (Sosnowiec) were analysed. Extreme ultra-short-term temperature changes were considered to be values less than or equal to 0.1 percentile (extreme temperature drops) and greater than or equal to 99.9 percentile (extreme temperature increases). The extreme ultra-short-term negative air temperature change was − 7.2°C/10 min, while the positive change was + 3.5 °C/10 min. Extreme ultra-short-term negative air temperature changes in southern Poland in January occur most frequently with the advection of air from the west (43% of cases), the inflow of maritime Polar old (transformed) air over Poland (25% of cases), western cyclonic (Wc) and north-western cyclonic (NWc) situations, a total of 34% of cases), the passage of the atmospheric front over southern Poland (59% of cases), especially a cold front (68% of cases with a front). Extreme ultra-short-term positive changes of air temperature in southern Poland in January occur most frequently with the advection of air from the south-west (43% of cases), the inflow of continental Polar air (42% of cases), anticyclonic situations (72% of cases), the occurrence of a high-pressure wedge over southern Poland (26% of cases), situations without atmospheric front (80% of cases). The direction of advection plays a secondary role in determining the values of extreme short-term changes in air temperature. More important is the speed of the influx of this air mass. Extreme ultra-short-term temperature changes are partly explained by circulation conditions. Rapid temperature changes can also occur as a result of small-scale processes in the atmosphere.

Impact of changes in climate and glacier configurations on runoff from the Langtang River basin, Nepal

Abstract. Climate change is rapidly altering Himalayan glaciers, jeopardizing downstream water resources. This study investigates the impact of changing air temperatures, precipitation, and glacier configurations on streamflow in the Langtang River basin, a vital Himalayan basin. Using a process-based glacio-hydrological model driven by bias-corrected reanalysis data, we simulate streamflow under various scenarios. Results reveal that, while current glacier conditions show increased runoff with higher temperatures and precipitation, future deglaciation scenarios project a decrease in total streamflow, highlighting the complex interplay between climate and glacier dynamics in basin hydrology. These findings emphasize the need for adaptation strategies to ensure water security in the face of evolving Himalayan hydrology.

Micrometeorological drivers affecting the variability of CO2 uptake in the Himalayan Oak and Pine dominated ecosystems: An assessment of causal relationships

Micrometeorological variability significantly impacts the structures, functions, and dynamics of ecosystems. However, the assessment of feedback and causal relationships among microclimatic drivers and various ecosystems in the Himalayan region is rarely evaluated. Here, we studied the micrometeorological drivers controlling the variability in the net ecosystem exchange (NEE) of Himalayan Oak (Banj-Oak/Quercus leucotrichophora) and Pine (Chir-Pine/Pinus roxburghii) dominated ecosystems, as NEE is an indicator of ecosystem functioning. We used half-hourly eddy covariance flux data of CO2 fluxes from two sites established over Pine and Oak dominated ecosystems in Uttarakhand, India. We conducted the analysis with the information theory-based Temporal Information Partitioning Networks (TIPNets) approach to generate weekly process networks. TIPNets represent directed lag-structured causal graphs to identify the causal relationships and capture the temporal association among the variables. Our analysis aimed to capture fluctuations in variables with up to 6 h of memory. Based on the data availability, we generated the weekly networks at both the sites for the monsoon and post-monsoon seasons of 2016 and 2017. In both ecosystems, the sub-daily scale variations among the micrometeorological variables are responsible for the fluctuations in NEE. The Pine ecosystem is found to be more sensitive to changes in air temperature (TA) and uptakes more CO2 as compared to the Oak ecosystem throughout the study period. The transfer entropy links show that the NEE of the Oak ecosystem is moisture-driven (precipitation and relative humidity), while the Pine ecosystem is heat-driven (TA and net solar radiation) in both seasons. The influence of precipitation is not observed within a short memory of 6 h in the Pine ecosystem. This is because lesser fine roots take time to show the precipitation signature on NEE through infiltration, soil moisture, and root water uptake, compared to Oak. However, the impacts of moisture stress are evident in the network structure of both ecosystems, with more causal links observed in the network during dry periods compared to wet periods.

The first firn core from Peter I Island – capturing climate variability across the Bellingshausen Sea

Abstract. Peter I Island is situated in the Bellingshausen Sea, a region that has experienced considerable climate change in recent decades. Warming sea surface temperatures and reduced sea ice cover have been accompanied by warming surface air temperature, increased snowfall, and accelerated mass loss over the adjacent ice sheet. Here we present data from the first firn core drilled on Peter I Island, spanning the period 2001–2017 CE. The stable water isotope data capture regional changes in surface air temperature and precipitation (snow accumulation) at the site, which are highly correlated with the surrounding Amundsen–Bellingshausen seas and the adjacent Antarctic Peninsula (r &gt; 0.6, p &lt; 0.05). The firn core data, together with the unique in situ data from an automatic weather station, confirm the high skill of the ERA5 reanalysis in capturing daily mean temperature and inter-annual precipitation variability, even over a small sub-Antarctic island. This study demonstrates the suitability of Peter I Island for future deep-ice-core drilling, with the potential to provide a valuable archive to explore ice–ocean–atmosphere interactions over decadal to centennial timescales for this dynamic region.

The profound influence of the North Atlantic Ocean on Northeast Asia: A comprehensive multi‐model study

AbstractWe assess the effects of the North Atlantic Sea surface temperature multidecadal variability on Northeast Asia using a set of sensitivity experiments (with a total of 530 ensemble members). We show that a warming of the North Atlantic Ocean leads to a strong and robust increase in temperature over Northeast Asia, which is replicated by a large majority of ensemble members. We show that the effect of the North Atlantic on Northeast Asia is model and season‐dependent. We focus on two seasons, for which response to the North Atlantic Ocean is the most robust (autumn) and the less robust (spring) as indicated by the number of models that simulate a statistically significant change in surface air temperature. We use a clustering method to identify the sources of differences between models in simulating the effects of warming in the North Atlantic. We find that the primary mechanism linking the North Atlantic to Northeast Asia is a perturbation of the circumglobal teleconnection pattern (i.e., of the upper tropospheric atmospheric circulation), which allows modulation of the near‐surface atmospheric circulation and an increase in temperature over East Asia. A second mechanism is related to the influence of the North Atlantic on the Pacific Ocean and the resulting effects on atmospheric circulation over Northeast Asia.