July Precipitation Research Articles

Climatic sensitivity and the growth prospects of Silver fir and European larch in the Carpathians in the light of observed climate changes

One consequence of climate change is the rapid extinction of spruce monocultures in the Carpathians. Therefore, the need has arisen to replace spruce with other highly productive species that ensure the stability and biodiversity of mountain forests, such as the Abies alba and Larix decidua. These co-occurring conifers show different successional and phenological characteristics: L. decidua is a light-demanding species that dominates in the early successional stages, while A. alba is a shade-tolerant tree. This study attempts to identify climatic factors that determine the tree-ring width of fir and larch in order to assess the growth prospects of these species in the context of the ongoing climate change. As a measure of the vitality of trees, tree-ring widths of 42 sub-populations of fir and 36 of larch from the area of the Western Carpathians were used. Regional growth patterns for each species were used to estimate the relationship between temperature/precipitation and radial growth. Linear correlation analyses and nonlinear Random Forest models were used. Fir growth was significantly positively influenced by the high temperature of January–March and July and the high precipitation of February and July of the year of tree-ring formation. Larch growth was positively affected by the high temperature of May and the low precipitation of April and September of the year of tracheid formation. Unlike larch, fir growth increased if May and June of the preceding year were warm. The dominant climatic factor influencing fir growth was February temperature, whereas for larch growth, it was the May temperature of the year of tree-ring formation. Most of the recently observed changes in climatic factors that are important for the growth of both species are favorable. Thus, increasing their share in the Carpathian forests seems fully justified, as this will contribute to the stability, productivity, and biodiversity of the region’s forests.

Inventory of shallow landslides triggered by extreme precipitation in July 2023 in Beijing, China

The extreme meteorological events caused by climate change have increasingly caused serious clustered landslides. A systematic and timely inventory of triggered landslides is a prerequisite for quantifying and evaluating the impact of extreme meteorological events. In addition, a landslide inventory can provide basic data for any subsequent analysis of the event or be used innovatively in landslide risk analysis. The Rainfall-induced Landslides in Beijing (RLBJ) inventory presented here contains data on 15,383 rainfall-induced shallow landslides triggered by a single extreme precipitation event in July 2023 in an area of ~3,250 km2 in western mountainous areas of Beijing, China. High-resolution satellite images before and after this rainstorm event were used to visually analyze the landslides. All landslides were reported as vectorized points and polygon features and classified according to their motion forms. This inventory is now freely available for the benefit of international geohazard researchers.

Climatic variation and risk assessment in a highly seasonal mammal

Abstract Climate change and its resulting effects on seasonality are known to alter a variety of animal behaviors including those related to foraging, phenology, and migration. While many studies focus on the impacts of phenological changes on physiology or fitness enhancing behaviors, fewer have investigated the relationship between variation in weather and phenology on risk assessment. Fleeing from predators is an economic decision that incurs costs and benefits. As environmental conditions change, animals may face additional stressors that affect their decision to flee and influence their ability to effectively assess risk. Flight initiation distance (FID)–the distance at which animals move away from threats–is often used to study risk assessment. FID varies due to both internal and external biotic and physical factors as well as anthropogenic activities. We asked whether variation in weather and phenology is associated with risk-taking in a population of yellow-bellied marmots (Marmota flaviventer). As the air temperature increased marmots tolerated closer approaches, suggesting that they either perceived less risk or that their response to a threat was thermally compromised. The effect of temperature was relatively small and was largely dependent upon having a larger range in the full data set that permitted us to detect it. We found no effects of either the date that snow disappeared or July precipitation on marmot FID. As global temperatures continue to rise, rainfall varies more and drought becomes more common, understanding climate-related changes in how animals assess risk should be used to inform population viability models.

Potential Amplifiers of Hydrological Drought: A Deep Dive into the Seasonal Variations of New, Young, and Old Water Fractions in the Stream Discharge of a Pre-Alpine Catchment

This study examines runoff generation processes by focusing on new, young, and old water fractions in the stream discharge within the Swiss pre-Alpine Alp catchment and its smaller tributaries, Erlenbach and Vogelbach. Young water represents a contribution from the three most recent rainfall-runoff events. This research utilises a four-year time series of daily stable water isotope data from stream water and precipitation to investigate seasonal variations. An extended two-component hydrograph separation method is applied to analyse the catchment water and tracer mass balance across both the event and pre-event time axes. The calculated new, young and old water components in stream discharge help estimate time-varying backward travel time distributions. Factors such as air temperature, snow depth, and evapotranspiration data are considered to understand isotope fractionation because of phase changes. The results suggest that discharge generated in autumn and winter may have longer backward travel times compared with spring or summer discharge. Additionally, forest cover influences water fractions older than 40 days. The study identifies a nivo-pluvial runoff regime, with new water fractions peaking in August (Erlenbach, Vogelbach) and January (Alp). Young water fractions reach their highest levels at the start of winter and during snowmelt, while old water fractions peak towards the end of snowmelt and in mid-autumn. The Alp catchment and its tributaries exhibit higher new and young water components than old water following a month of low precipitation and high evapotranspiration in July. These findings are significant in light of the projected drier summers in Central Europe.

Redistribution of debris‐flow sediment following severe wildfire and floods in the Jemez Mountains, New Mexico, USA

AbstractSevere fire on steep slopes increases stormwater runoff and the occurrence of runoff‐initiated debris flows. Predicting locations of debris flows and their downstream effects on trunk streams requires watershed‐scale high‐resolution topographic data. Intense precipitation in July and September 2013 following the June 2011 Las Conchas Fire in the Jemez Mountains, New Mexico, led to widespread debris flows in the watershed of Rito de los Frijoles. We differenced lidar Digital Elevation Models (DEMs) collected in 2010 and 2016 to map subwatersheds experiencing debris flows and changes in elevation of the trunk stream. Debris flow occurrence was well predicted by previous assessments of debris‐flow hazard; debris flows occurred in 7 of 9 sub‐basins where the debris‐flow hazard was above 60% for the 25‐year rainfall event, and in 0 of 21 basins where debris flow hazard was less than 60%. Debris flows resulted in fan deposition at the confluence with the trunk stream followed by transport during three documented floods. The bed of the 22 km trunk stream increased in elevation by a mean of 0.29 m, but the local change in thalweg elevation was controlled by inputs of water and sediment and longitudinal variation in gradient. Downstream of the mouths of tributaries with debris flows, the thalweg of the trunk stream rose as much as 2 m. Downstream of the mouths of tributaries without debris flows the thalweg of the main stem degraded by as much as 2 m, mobilizing sediment that was then deposited further downstream where the gradient of the trunk stream decreases. In conclusion, the transport of sediment generated by debris flows was predictably related to spatial variation in sediment supply, discharge and gradient.

European vineyards and their cultural landscapes exposed to record drought and heat

CONTEXTEuropean vineyards, producing over 50% of the world's wine and hosting significant cultural landscapes, face threats from climate change and related severe weather events. The summer of 2022, especially July, posed significant challenges due to extreme drought and high temperatures. However, this period also provided an opportunity to study how such events might involve viticulture in Europe and to explore mitigation solutions. OBJECTIVEThe objectives are (1) to characterize the severity of the extreme event of July 2022 in European wine regions regarding primary climatic parameters, (2) map vineyards at risk due to agricultural drought and high land surface temperature, and (3) discuss the role of various water-related interventions for mitigating similar events. METHODSAfter identifying the locations of European vineyards using the Corine Land Cover 2018 (CLC2018), open-access satellite data were employed to: (1) assess anomalies in Maximum Air Temperature (NATm), Land Surface Temperature (LST), Precipitation (P), and Soil Moisture (SM) in July 2022 compared to long-term averages; (2) identify regions at higher risk that experienced extreme agricultural drought (Vegetation Health Index, VHI = Extreme) and LST > 35 °C. RESULTS AND CONCLUSIONSIn July 2022, European vineyards experienced an average increase of 11% in NATm, a 9% rise in LST, and a reduction of 47% in P and 30% in SM compared to historical averages. 18% of European vineyards were at risk of drought and excessive heat, particularly in Portugal (31%), France (27%), and Italy (21%), including 10 viticultural cultural landscapes. Findings highlight the urgent need for long-term sustainable water management practices over emergency interventions. This research supports informed decision-making, emphasizing that climate resilience is necessary for preserving the cultural heritage of European wine-growing areas. SIGNIFICANCEThis research provides an overview of the dynamics of extreme events on viticulture at a continental scale, promoting climate-aware viticultural systems and offering insight scalable to global viticulture under changing climatic conditions.

Дендроэкологическое исследование роста осины в условиях Московской области

According to V.A. Dragavtsev's concept, the reaction of the annual ring to the provocative environmental background of different years creates a “portrait” of adaptive polygenic genotype systems. By comparing the reactions of the main forest-forming species from an ecologically homogeneous habitat, it is possible to assess the level of similarity of their ecological properties. Cluster analysis of tree-ring chronologies of aspen and species growing together with it, correlation analysis of chronologies and indexed chronologies, as well as time series of meteorological factors and Fourier spectral analysis have been used for a dendroecological research into aspen growth features in the conditions of the Molokchinskiy Botanical and Entomological Reserve of the Sergiev Posad District of the Moscow Region. To compare with the chronologies of aspen from two stands, the chronologies of European white birch, English oak, grey alder and Norway spruce have been used. It has been established that the cluster analysis of indexed chronologies based on calculating the squared Euclidean distance and combining the chronologies into groups according to the rule of complete linkage distinguishes aspen chronologies into a separate cluster, very distant from the other species under consideration. According to the correlation analysis of indexed chronologies, the dynamics of radial increment of aspen is most closely related to the dynamics of radial increment of European white birch and gray alder. Moreover, the maximum correlation coefficient (0.71) is observed for the chronologies of aspen from two different stands. Among the climatic factors, the main limiting influence on aspen increment is exerted by July precipitation in the year of the annual ring formation and August precipitation in the year preceding the year of the annual ring formation. The response to precipitation in August last year is specific to aspen stands and has several options for ecophysiological interpretation. According to Fourier spectral analysis, aspen chronologies have the most pronounced cyclic component with a period of 10.4 years, which completely coincides with the cyclic component of the time series of Wolf numbers in the time interval under consideration. This distinguishes aspen from the rest of the studied forest-forming species. A conclusion has been made about the specificity of the dynamics of the radial growth of aspen in comparison with other forest-forming species under study.

Influence of weather conditions in Central Polissia, Ukraine, on the expression of quality indicators in potato cultivars of different maturity groups

For Ukrainians, potatoes are a key foodstuff and the most important strategic crop in the vegetable segment, and therefore it is vital to investigate the quality characteristics of potato tubers. The purpose of this study was to investigate the influence of various meteorological factors on the taste and starch content of tubers of different potato cultivars. The study employed laboratory, analytical, mathematical, and statistical methods. Both positive and negative correlation between starch content in tubers, taste, average monthly temperature, and precipitation were found in cultivars of different ripeness groups. For some potato cultivars, the positive effect on the starch content in tubers was due to the synergistic interaction of temperatures in August and precipitation in July, while for other cultivars this effect was determined by temperature and precipitation in August. It was found that an increase in temperature in August contributed to the improvement of the taste characteristics of early-ripening cultivars, while for middle early and mid-ripening genotypes, increased temperatures in June and August were key factors, and middle-late cultivars responded to increased precipitation in August. For each of the 19 cultivars studied, periods with a positive effect of average monthly temperature and precipitation on the improvement of taste were identified. The cluster analysis helped to identify potato cultivars with high starch content – Lietana, Opillia, Vzirets, and Oleksandryt, with high taste qualities – Lietana, Mezhyrichka 11, Vzirets, Avanhard, Partner, Oleksandryt, Fanatka, Rostavytsia, and Opillia. The findings of this study can serve as a scientific basis for the formulation of policies aimed at mitigating the effects of climate change and adapting existing cultivars to support sustainable potato production in a particular region and creating new plastic potato genotypes with sustainable quality characteristics

Utilizing Machine Learning Framework to Evaluate the Effect of Climate Change on Maize and Soybean Yield

In recent years, climate change patterns and extreme weather events have adversely affected agricultural production and have raised concerns about its effect on crop yields. These changes can affect the crop yield in many ways including the changes in the length of the growing season, planting and harvest time windows, precipitation amount and frequency, and the growing degree days, etc. So, it is important to analyze the effect of climate change on yield variability for a better understanding of its effect on the crops. This study aims to analyze the historical monthly county-level data for the state of Ohio to quantify maize (Zea mays) and soybean (Glycine max) yield temporal variability and to study the impact of proposed climate change scenarios on the yield. Machine learning algorithms were used to model the effect of monthly temperature and precipitation levels on yield variability, and to study the effect of climate change scenarios on yield. In addition, yield prediction models were integrated with proposed climate change scenarios for higher and lower emissions scenarios to predict the maize and soybean yield for the year 2100. To model the effect of weather parameters on temporal yield variability, the Random Forest model outperformed with RMSE of 0.61 Mt/ha and R2 of 0.73 for maize and with RMSE of 0.21 Mt/ha, R2 of 0.64 for soybean crop. Maximum temperature for July which has a negative correlation with yield was found to be the most dominant parameter for maize yield followed by the precipitation in August, July, and June which have a positive correlation with maize yield. Precipitation in August was found to be the most dominant weather parameter for soybean yield followed by maximum temperature in July. Based on the projected average increase in Ohio’s temperature and precipitation levels alone, maize yield was predicted to drop by 13.2% or 18.5% respectively due to lower emissions and higher emissions climate change scenario of Ohio. Similarly, a 6.64% and a 9.63% drop is expected in the soybean yield by the year 2100 for both lower emissions and higher emissions climate change scenarios. In economic terms based on current commodity values, this is an astounding loss of 254.7 to 369.7 million USD for maize and 535.9 – 751.1 million USD for soybean crop to the state of Ohio.

Drivers of Hymenoscyphus fraxineus Infections in the Inner-Alpine Valleys of Northwestern Italy

Fraxinus excelsior L. (ash) is a key forest tree species challenged by Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya, the causal agent of ash dieback. The goals of this study were (I) to assess the presence, spatial distribution, and incidence of H. fraxineus in the inner-alpine valleys of northwestern Italy, along with the severity of ash dieback; (II) to model the probability of infection by H. fraxineus based on environmental variables; (III) to reconstruct the direction of provenance of the front of invasion of the pathogen; and (IV) to test whether H. fraxineus has replaced the native relative Hymenoscyphus albidus (Gillet) W. Phillips, a saprobe of ash litter. By combining phytosanitary monitoring and samplings in 20 forest stands, laboratory analyses, and statistical modelling, this study showed that H. fraxineus was present in 65% of stands with an average incidence of 27%, reaching peaks of 80%. Rainfalls were the most relevant drivers of the probability of infection by H. fraxineus, rising up to 80% with the increased precipitation in April and July. Other drivers included elevation, maximal temperatures, latitude, and longitude. The front of invasion likely moved from Italy and/or Switzerland, rather than from France, while the replacement of H. albidus is uncertain.

Midsummer precipitation prediction over eastern China by the dynamic downscaling method

AbstractThis study assesses the midsummer precipitation prediction over eastern China by the dynamic downscaling method. Based on the Climate Forecast System version 2 of the National Centers for Environmental Prediction and the Weather Research and Forecasting Model, the prediction performance of global and regional models on the July precipitation over eastern China is further analyzed by hindcast experiments from 1982 to 2010 and prediction experiments from 2011 to 2021. The results suggest that the regional model forced by the global model can noticeably improve the prediction skill for precipitation in eastern China, especially in the region from the South of North China to the Yangtze River Basin, referred as the northern China in this paper. In addition, we perform a diagnostic analysis of the reason for the improvement of the model prediction skill. The results indicate that the high resolution of the regional model and the refinement of physical process parameterizations contribute to improving the simulation ability for the East Asian atmospheric circulation pattern, heat flux, especially for the meridional teleconnection pattern in East Asia and the sensible heat flux in the northern China, thus further improving precipitation prediction.

Soil water dynamics and deep percolation in an agricultural experimental area of the North China Plain over the past 50 years: Based on field monitoring and numerical modeling

The unregulated irrigation systems used in the late 20th century have led to increasingly severe deep percolation (DP) in the agricultural irrigation areas of the North China Plain. This has become an important factor limiting the efficient utilization of water resources and sustainable environmental development in these irrigation areas. However, the thick vadose zone is hydrodynamically exceptionally complex. The soil hydrological cycle is constantly changing under the influence of major climate change and human activity, thereby causing changes in DP that are difficult to quantify accurately. Here, the Luancheng Agricultural Irrigation District in North China was selected for a continuous 20-year in situ experiment. Soil-water dynamics were monitored using neutron probes and tensiometers, to determine the complete annual soil-water cycle and the hydrodynamic properties of the thick vadose zone irrigation district. For 1971–2021, DP was simulated using the HYDRUS-1D model and was verified by fitting observed values. Soil water content (SWC) exhibited similar trends in years that differed in terms of the amounts of irrigation and precipitation. The 0–100 cm soil layer was significantly affected by precipitation and other factors, and recharge >60 mm/d caused percolation. DP occurred mostly after irrigation or during the period of intensive precipitation in July–October. The maximum percolation rate was 16.9 mm/d under the present irrigation method. The main factors leading to DP were soil water storage capacity (R2 = 0.86) and precipitation (R2 = 0.54). Under the evolution of irrigation measures in the last 50 years, the average DP has gradually decreased from 574.2 mm (1971–1990) to 435.5 mm (2005–2021). However, a substantial amount of precipitation and irrigation water infiltrated the soil and percolated into the deep soil layer without being utilized by the crop. Therefore, there is an urgent need to consider measures to reduce DP to improve water-use efficiency in agriculture.

Soils of xerophytic meadows of the Middle Podesen’ya: on the issues of accumulation of organic substances and biochemical activity

Relevance. Natural meadow communities, belonging to the dry meadows group, in the conditions of a decrease in floodplain of the leading water artery in the Bryansk region — the Desna River are characterized by significant changes in the mode of economic use. However, a significant part of dry meadows is used as pasture lands, so the regime of intensive exploitation of these lands significantly changes the ecological regimes of phytocenoses, reducing the carbon-depositing functions. For xerophytic (dry) meadows of natural origin, the establishment of soil carbon reserves, the identification of biochemical and microbiological activity is especially important in the light of the low stability of these communities under pasture load and wide distribution throughout the territory of the Middle Podesen’ya.Methods. The research provided for field route studies and in-house data processing using the methods of trial sites, the method of ecological and floral classification, the method of ecological scales (according to G. Ellenberg), ecological and chemical methods — determination of organic carbon, the weight method, biochemical and microbiological methods for the study of the biocompatible body.Results. For the soils of xerophytic (dry) meadows, for the first time, carbon-absorbing capacity, enzymatic activity for urease, catalase, cellulase, depending on the phytocenotic complex, has been established for the Middle Podesen’ya. A positive strong correlation has been established with organic carbon and average monthly precipitation in June, July and August. Over a two-year observation period, the amount of total organic carbon in the soil changed in a number of associations communities: Festuco ovinae-Koelerium delavignei > control > Agrimonio eupatoriae-Poetum angustifoliae > Caro carvi-Deschampsietum > Anthoxantho-Agrostietum tenuis > Hieracio pilosellae-Agrostietum tenuis > Koelerio delavignei-Festucetum rubrae > Anthyllidi-Trifolietum montani > Polygalo vulgaris-Anthoxanthoetum.

Change and influence of agroclimatic conditions on oat yield in Yakutia

The results of the dynamics analysis of multi-year meteorological indicators and study of their influence on the yield of the released oat varieties in different agroclimatic zones of Yakutia are presented. It is shown that in the period from 1960 to 2021 the mean annual air temperature in Central Yakutia (Pokrovsk meteorological station) increased annually by 0.045 °C, from 1999 to 2021 – by 0.088 °C, the number of dry years in June increased from 67 to 92% due to a 21% increase in years with medium (HTC = 0.41-0.60) and very strong (HTC < 0.21) drought. In July, drought was recorded in 50% of the years, in August – in 38%. In all agroclimatic zones in the period from 2014 to 2021 for June – August the average daily air temperature annually increased by 0.16...0.34 °С and their sum by 14...28 °С, with precipitation decreasing by 3-16 mm and HTC value by 0.04-0.12 units. Climate change from 2014 to 2021 was 3 to 8 times more intense than from 1999 to 2022. There was a strong variability of yields of the released oat varieties in each agroclimatic zone: Central – from 0.38 to 2.14 t/ha (V = 60–73%), Zarechnaya – from 0.31 to 3.55 t/ha (V = 41–49%), Srednelenskaya – from 1.51 to 4.66 t/ha (V = 30–36%). The greatest annual decrease in grain yield of oat varieties (by 0.25–0.26 t/ha) was observed in arid agroclimatic zones – Central (Yakutsk SCTS) and Zarechnaya (Megino-Kangalassky SCTS) – compared to the wetter Srednelenskaya zone (Olyokminsky SCTS – by 0.10 t/ha). More significant influence on the yield in the Central and Zarechnaya zones was made by precipitation and HTC of the growing season (r = 0.77...0.84), in the Srednelenskaya zone – by temperature (r = – 0.79). Negative effect of temperature on the yield in the Central zone was observed in June (r = – 0.83), Zarechnaya zone - in July (r = – 0.83), in the Srednelenskaya zone – in August (r = –0.86). Precipitation and HTC had the greatest influence on the yield in the Central zone in June and July (r = 0.56...0.59), Zarechnaya zone – July and August (r = 0.60...0.76). In the Srednelenskaya zone the relationship of the yield with precipitation and HTC in June and July was positive (r = 0.23...0.37), in August – negative (r = – 0.57...– 0.71). Significant variability in grain yields of the released oat varieties indicates the variability of weather conditions and the need to cultivate oat varieties that provide a more stable yield in different agroclimatic zones of Yakutia.

Rapid Warming Exacerbates Winter Drought Stress in Trees at High-Altitude Areas in Northeast China

Against the background of global warming, trees in high-latitude and high-altitude areas are more sensitive to rapid warming. Revealing the response patterns of trees at different altitudes to rapid warming in typical alpine mountain environments can help to predict the future distribution of forests in the region and the associated changes in the timberline. This study used tree-ring width data (band sampling) from Dahurian larch (Larix gmelinii Rupr.) along an altitudinal gradient (970–1409 m) on Oakley Mountain to establish 10 chronologies and to analyze the growth–climate response of larch to warming and altitudinal changes along a gradient. The results showed that before rapid warming, larch growth was strongly influenced mainly by precipitation in July–August, while after warming, the growth was controlled mainly by precipitation (snowfall) in winter (October–April) and showed a significant positive correlation with the SPEI in winter and a negative correlation with temperature in February–April (early spring). This indicates that the rapid warming event led to a drastic change in the water heat balance during the pre-growth period of the trees in the study area, which shifted the tree growth from being restricted by drought in the growing season before warming to being restricted by winter drought (i.e., the lagged effect of snowfall in the pre-growing season) after warming and that the trees at low altitudes suffered from more severe winter drought. In the future, as the global climate warms further, the growth of mountain larch at low altitudes (below 1200 m) will continue to decrease, and the coupling of winter snowfall and seasonal (February–April) warming will increase the upper altitude limit at which winter drought occurs for larch in the study area; additionally, larch at higher altitudes will be able to cope with this ecological process better.

Analysis of the influence of climatic conditions on the tax potential of Russian regions using cluster analysis

The tax burden of the regions is influenced by a whole range of factors, among which it is necessary to take into account the natural and climatic conditions. After all, the specialization of the regions, production capabilities, production volumes and, accordingly, the level of tax revenues to the consolidated budget of the Russian Federation depend on them. The article analyzes the tax potential of regions depending on the climatic factor. The subject of this study is a system of statistical indicators characterizing the natural and climatic conditions of the regions (temperature and precipitation in July and January for three years) and the economic results of their activities, including tax revenues to budgets. The aim of the work is to assess the influence of the climatic factor on the tax potential of the regions using the grouping method of cluster analysis. The research method is cluster analysis (k-means method), implemented using the R programming language and its packages, which allows combining regions according to the similarity in climatic conditions, while minimizing variation within groups and maximizing intergroup differences. The results of the study can be applied in the development of recommendations at the state level on optimizing the tax burden of regions for regions with similar conditions. The novelty of the study lies in the possibility of assessing and comparing the characteristics of regions with similar climatic conditions in terms of tax potential, which is necessary to develop measures for the development of regions and increase their tax potential. As a result of the study, the influence of the climatic factor on the tax potential of the regions and the need to take it into account in combination with other factors is proved.

Characteristics of mesoscale convective systems and related precipitation in the three‐river‐source region of China

AbstractMesoscale convective systems (MCSs) are important air water sources to the Three‐river‐source (TRS) region known as the “Chinese water tower.” Using hourly equivalent blackbody temperature (TBB) data from geostationary satellites of Chinese Fengyun‐2 series during the warm season (May–August) in 2005–2020 and an objective algorithm, MCSs in the TRS are divided into meso‐α (MαCS), meso‐β (MβCS), and meso‐γ (MγCS), and MαCS and MβCS are subdivided into larger meso‐α (LMαCS), smaller meso‐α (SMαCS), larger meso‐β (LMβCS), and smaller meso‐β (SMβCS). Results show that a high‐frequency zone of MCSs in the TRS distributes along the source of the rivers. Most MCSs, except LMαCS, develop and dissipate in situ. The interannual variation in MCS frequency exhibits a decreasing trend, especially after 2013, mainly due to the decrease in MCSs in the source region of the Yellow–Lancang River. The occurrence of MCSs peaks in August, but MCSs are most likely to produce precipitation in July and usually generate between 1600–2200 h LST (UTC + 8). The precipitation caused by MCSs to the total precipitation (precipitation ratio, PR) accounts for about 40%; MCS PR is closely related to, and increases with, the horizontal scale of the MCS, with MαCS PR being the highest, exceeding 67%. The contribution of MCSs to precipitation is mainly reflected in weak precipitation, smaller than 10.0 mm/h. Most of the maximum precipitation of MCSs appears after MCSs reach their prime, with the maximum lag by MαCS up to 2 h.

Climatic implications in earlywood and latewood width indices of Chinese pine in north central China

Latewood width (LWW) indices of trees are considered a reliable proxy of summer precipitation in the Northern Hemisphere. However, the strong coupling and high correlation between earlywood width (EWW) and LWW indices often prevent registration of climate signals of the LWW index. In this study, 328-year-long earlywood width and latewood width chronologies were developed from Chinese pine at two sites in the Hasi Mountains, north central China. The climate responses of these chronologies were analyzed and the LWW index used to derive summer precipitation signals. Correlation analyses showed that LWW was particularly influenced by earlywood growth and recorded stronger climate signals of the previous year as EWW, rather than those of the current year with infrequent summer climate signals. However, after removing the effect of earlywood growth using a simple regression model, the adjusted LWW chronology (LWWadj) showed a strong relationship with July precipitation in dry years. This suggests that the LWWadj chronology has the potential to be used to investigate long-term variability in summer precipitation in drought-limited regions.

АГРОКЛИМАТИЧЕСКИЕ РЕСУРСЫ ФОРМИРОВАНИЯ КАЧЕСТВА ЗЕРНА ЯРОВОЙ ПШЕНИЦЫ В РЕСПУБЛИКЕ БАШКОРТОСТАН

The results of the study of the dependence of the grain quality of soft spring wheat (Tríticum aestívum L.) on the main agroclimatic resources in the territory of the Republic of Bashkortostan are presented. Field experiments were carried out in different geographical locations of the republic according to the methodology of the State Variety Trial. Laboratory analyses of grain quality were carried out according to the methodology set forth in the State Standards. It has been established that the quality of soft spring wheat grain in the Republic of Bashkortostan largely depends on agroclimatic resources. In recent years, there has been a manifestation of global climate change on the territory of the republic. The amount of gluten in the grain depends to a large extent on the change in the average daily air temperature in June (r = 0.741) and to a slight extent on the average daily temperature in July (r = 0.359). The degree of dependence of gluten content increases significantly with an increase in the sum of air temperatures during the active vegetation of spring wheat (r = 0.812). The dependence of gluten content on the sum of temperatures in June and July is straightforward, and an increase in heat resources during the vegetation period of spring wheat plants by 10 °C contributes to an increase in the gluten content in grain by 0.73 %. Heat resources have a comparatively weak effect on other indicators of wheat grain quality. The correlation coefficient between gluten content and precipitation in July was 0.764. An increase in precipitation in July by 10 mm leads to a decrease in the gluten content in the grain of spring soft wheat by 0.49 %. High moisture availability also leads to the formation of soft spring wheat grain with low vitreousness (r = –0.547) and natural weight (r = –0.521). Moisture resources had a small effect on the gluten deformation index (r = 0.227). Precipitation in June has a weak effect on the quality indicators of spring soft wheat grain. The correlation coefficients between the sum of precipitation in June and the quality indicators were positive and ranged from 0.223 to 0.341

Синоптические условия повышения уровня рек на юге Иркутской области и Забайкалья в июле 2023 года

The article discusses natural and anthropogenic factors of rising river levels and associated environmental consequences, existing probabilistic estimates of the amount of floods using various hydrological and climate models. Orographic, climatic and circulation features of the occurrence of floods in the Irkutsk region are identified. A study was carried out of the circulation and weather factors of increasing the intensity and duration of precipitation in early July 2023, which was accompanied by an increase in river levels in the south of the Irkutsk region and the Baikal region. The dynamics of atmospheric processes near the Earth's surface and at the levels of isobaric surfaces AT850 hPa, AT-700 hPa, AT-500 hPa and AT-300 hPa, reflecting the conditions of surface and highaltitude cyclo- and frontogenesis, are analyzed. The contribution of advective flows of heat and moisture, mesojets in the middle troposphere and upper tropospheric jet currents in increasing the amount and duration of atmospheric precipitation is highlighted. A significant contribution to the increase in precipitation and the rise in river levels was made by moist air masses moving in the lower troposphere from the water area of the lake. Baikal, in the middle troposphere from the Yellow Sea. The time of passage of the flood and the height of the rise in the level of individual watercourses as a result of the rains were estimated.