Changes In Distribution Of Precipitation Research Articles

The impact of climate change on agricultural land use in Ukraine

The article analyses the impact of climate change on agricultural land use in Ukraine. Given the growing global consumption of food and a growing population, agriculture is becoming a key element of the country’s stability and development. However, climate change, such as rising temperatures, changes in precipitation distribution, and the frequency of extreme weather events, can significantly affect the yields and efficiency of agricultural activities. Global trends in climate change, which is one of the most pressing threats with a long-term negative impact on the population, environment and economy, are investigated. The article highlights the positive (changes in the conditions and timing of harvesting, increased efficiency of fertiliser application, etc.) and negative (deterioration of grain quality, increased number of droughts, etc.) consequences of climate change on agricultural land use. The study includes an analysis of long-term climate data in Ukraine, as well as an assessment of changes in land cover, crop distribution and crop production. The study aims to determine the impact of climate change, in particular temperature rise, changes in precipitation and extreme weather events, on agricultural production and land use in Ukraine. The article analyses data from various sources, including meteorological observations and statistical data using modern geoinformation technologies. Changes in the distribution of crops, crop yields and yields depending on climate change are investigated. The study also assesses the possible consequences of these changes for Ukraine’s food security, economy and environment. The results of the study are important for decision-making in the field of agricultural policy and development of the agricultural sector, ensuring the sustainability of agricultural products and reducing the vulnerability of agriculture to climate change. They can serve as a basis for developing climate change adaptation strategies and maintaining the sustainability of the country’s food security in the face of climate change.

Critical Assessment 43: Microstructural and mechanical properties of friction stir additively fabricated SiC-Reinforced AA6061 build

Friction stir additive manufacturing was employed to fabricate a SiC-reinforced AA6061 composite. The tool with a pin length of 4.5 mm (plunge depth of 50% into the lower layer thickness) was used for the experiment. The stir zone consisted of fine, equiaxed grains due to dynamic recrystallisation. Variations in grain size, as well as changes in precipitate distribution, size, and morphology, were detected along the build direction. Hardness and tensile strength varied across layers, with the top slice having the greatest values of 104.2 HV and 268.4 MPa, respectively. Notably, the FSAM build demonstrated improved ductility with a maximum of 58.98%, mostly ascribed to fragmentation and partial loss of grain-boundary phases, as well as strong interfaces that delayed necking.

Changes in Future Precipitation Mean and Variability across Scales

AbstractChanges in precipitation variability can have large societal consequences, whether at the short time scales of flash floods or the longer time scales of multiyear droughts. Recent studies have suggested that in future climate projections, precipitation variability rises more steeply than does its mean, leading to concerns about societal impacts. This work evaluates changes in mean precipitation over a broad range of spatial and temporal scales using a range of models from high-resolution regional simulations to millennial-scale global simulations. Results show that changes depend on the scale of aggregation and involve strong regional differences. On local scales that resolve individual rainfall events (hours and tens of kilometers), changes in precipitation distributions are complex and variances rise substantially more than means, as is required given the well-known disproportionate rise in precipitation intensity. On scales that aggregate across many events, distributional changes become simpler and variability changes smaller. At regional scale, future precipitation distributions can be largely reproduced by a simple transformation of present-day precipitation involving a multiplicative shift and a small additive term. The “extra” broadening is negatively correlated with changes in mean precipitation: in strongly “wetting” areas, distributions broaden less than expected from a simple multiplicative mean change; in “drying” areas, distributions narrow less. Precipitation variability changes are therefore of especial concern in the subtropics, which tend to dry under climate change. Outside the tropics, variability changes are similar on time scales from days to decades (i.e., show little frequency dependence). This behavior is highly robust across models, suggesting it may stem from some fundamental constraint.

Precipitation response to extreme soil moisture conditions over the Mediterranean

The intimate link between soil moisture and precipitation makes it a “chicken-and-egg situation” that challenges climate studies of the continental water cycle. This association is particularly acute over the Mediterranean, increasingly exposed to droughts with climate change. This study aims at deciphering the impact of spring soil moisture state in the Mediterranean on subsequent warm season precipitation. In an idealized setup, two distinct climate models are used to generate extreme dry or wet soil conditions, and run climate simulations initialized and/or forced by these conditions. Changes in precipitation distribution and persistence are analyzed and where applicable compared to composites from a reanalysis. Spring soil moisture anomalies are found to be very persistent, but the precipitation response is largely model dependent. Overall, dry soils lead to a reduction of precipitation for early summer months and conversely for wet soils although with a fainter and less robust signal. On the other hand, wet soils tend to favor the persistence of precipitation throughout summer over several sub-regions. Our results highlight the stringent need to reduce the wide array of uncertainties associated to soil moisture, land-atmosphere coupling and convection in climate models, before ascertaining that soil moisture initialization could provide more skillful sub-seasonal to seasonal precipitation prediction.

Inverting Topography for Landscape Evolution Model Process Representation: 3. Determining Parameter Ranges for Select Mature Geomorphic Transport Laws and Connecting Changes in Fluvial Erodibility to Changes in Climate

We review select mature geomorphic transport laws for use in temperate ridge and valley landscapes and compile parameter estimates for use in applications. This work is motivated by a case study of sensitivity analysis, calibration, validation, multimodel comparison, and prediction under uncertainty, which required bounding values for parameter ranges. Considered geomorphic transport formulae span hillslope sediment transport, soil production, and erosion by surface water. We compile or derive estimates for the parameters in these transport formulae. Additionally, we address a common challenge—connecting changes in precipitation distribution to changes in effective erodibility—by using a simple hydrologic model and a method to estimate precipitation distribution parameters using commonly available data. While some parameters are reasonably well constrained, others span orders of magnitude. Some, such as soil infiltration capacity, have a direct physical meaning but are challenging to measure on geologically relevant timescales. Through the process of compiling these ranges we identify common challenges in parameter determination. The issue of comparable units derives from considering an exponent as an empirically inferred coefficient rather than as an expression of a fundamental relationship. The issue of appropriate timescales derives from the mismatch between human measurement and geologic timescales. This contribution thus serves both as a practical compilation for applications and as a synthesis of outstanding challenges in parameter selection for geomorphic transport laws.

Sensitivity of terrestrial carbon cycle to changes in precipitation regimes

Abstract Climate change critically affects the carbon cycle of terrestrial ecosystems and thereafter the climate-carbon feedback. Previous studies have addressed the changes in temporal and spatial distribution of precipitation, termed as altered precipitation regimes. However, the response of terrestrial carbon cycle to the changes remain unclear. In this study, we used three process-based models to investigate the effect of changes in precipitation regimes on interannual variability (IAV) of gross primary productivity (GPP), net ecosystem productivity (NEP) and ecosystem respiration (RE). Annual sum of precipitation (PRE) and its monthly distribution, including its uniformity (PCI, precipitation concentration index) and timing (PCT, precipitation center time index), were used to describe the changes in precipitation regimes. Our results showed that the anomalies of both GPP and NEP in most biomes can be dominantly explained by anomalies of PRE. In addition, we also found that PCI and PCT were responsible for carbon dynamics in some specific biomes. For example, PCI dominated anomalies of both GPP and NEP in evergreen broadleaf forests (EBF), and a lower PCI (more uniform) is conducive to the increase of GPP and NEP. PCT is critical in driving the anomaly of GPP in mix forest (MF), grassland (GRA) and barren vegetation (Barren), and more precipitation distributed in early growing season benefits the increase of GPP. The sensibility of carbon cycle to changes in precipitation is biome specific, being likely due to the mismatch between water use ratio (WUR, defined as the ratio of transpiration to evapotranspiration) and precipitation distribution, implying that changes in distribution of precipitation among seasons/months may change the water availability. Our findings highlighted the necessity to pay more attention to the effects of altered precipitation distribution on changes in ecosystem multifunctionality related to carbon cycle.

Precipitation Regime Shift Associated with the Pacific Decadal Oscillation in the Maritime Continent

Recent changes in precipitation regime in South-East Asia are a subject of ongoing discussion. In this article, for the first time, evidence of a precipitation regime shift during the mid-1970s in the Northern Hemispheric part of South-East Asia is demonstrated. The detection of regime shifts is made possible by using a new comprehensive dataset of daily precipitation records (South-East Asian Climate Assessment and Dataset) and applying a novel Bayesian approach for regime shift detection. After the detected regime shift event in the mid-1970s, significant changes in precipitation distribution occurred in the Northern Hemispheric regions—Indochina Peninsula and the Philippines. More specifically, dry days became up to 10% more frequent in some regions. However, no precipitation regime shift is detected in Southern Hemisphere regions—Java and Northern Australia, were the number of observed dry days increased gradually.

Climate change impacts on streamflow at the upper Jordan River based on an ensemble of regional climate models

Study RegionThe upper Jordan River is the major water resource in Israel, a country which suffers from increasing shortage of natural water resources. Study FocusIn this study, we apply for the first time to this area an approach based on an ensemble of regional climate models, verify their trends vs. observations for a control period and use them for simulating future discharges of the Jordan River. New Hydrological Insights for the RegionThe results of this study show that the observed negative trend of precipitation for the control period is also simulated by the climate models ensemble and projects a continued decreasing trend to the near future and further into the far future. Using the GR6J daily hydrological model for evaluating the effects of the predicted climate changes on the hydrological cycle in the region shows an increase in potential evaporation and a decrease in streamflow volumes in the Jordan River, Northern Israel. The results reveal and quantify the changes in rainfall–runoff relationships. These changes in the hydrological cycle in the region can be explained by changes in precipitation distribution and duration and decrease in soil moisture caused by the increase in evaporation. Results presented in this study could imply major consequences for the region. The findings here are relevant not only to Israel but also to the surrounding countries.

Climate change impacts on water balance in Western Bohemia and options for adaptation

Abstract Several basins in Western Bohemia are regularly confronted with water scarcity problems during dry periods that have far-reaching impacts on stream ecology and the availability of drinking water for users. This paper presents a hydrological balance assessment of catchments in Western Bohemia for present and future conditions together with possible directions for climate change adaptation at the local scale. Assessment of climate change impacts on hydrological balance components using an ensemble of regional climate models revealed an increase in air temperature for all months during the year leading to an increase in evaporation. Along with changes in precipitation distribution during the year (increasing winter precipitation and decreasing summer precipitation), groundwater recharge and groundwater storage in general both decrease. Adaptation measures such as water transfers and the construction of water reservoirs are assessed with respect to the goal of increasing water availability in the Western Bohemia region during dry periods.

Impact of water scarcity on spruce and beech forests

One of the greatest threats posed by ongoing climate change may be regarded the drought caused by changes in precipitation distribution. The aim of presented study was to characterize reactions to dry conditions and conditions without drought stress on gross primary production (GPP) and net ecosystem production (NEP) of spruce and beech forests, as these two species dominate within the European continent. Daily courses of GPP and NEP of these two species were evaluated in relation to an expected decrease in CO2 uptake during dry days. The occurrence of CO2 uptake hysteresis in daily production was also investigated. Our study was performed at Bilý Křiž (spruce) and Stitna (beech) mountain forest sites during 2010–2012 period. We applied eddy covariance technique for the estimation of carbon fluxes, vapor pressure deficit and precipitation characteristics together with the SoilClim model for the determination of drought conditions, and the inverse of the Penman–Monteith equation to compute canopy conductance. Significant differences were found in response to reduced water supply for both species. Spruce reacts by closing its stomata before noon and maintaining a reduced photosynthetic activity for the rest of the day, while beech keeps its stomata open as long as possible and slightly reduces photosynthetic activity evenly throughout the entire day. In the spruce forest, we found substantial hysteresis in the light response curve of GPP. In the beech forest, the shape of this curve was different: evening values exceeded morning values.

Spatio-temporal changes in atmospheric precipitation over south-western Poland between the periods 1891\u20131930 and 1981\u20132010

In this paper, we quantify the changes in precipitation distribution in south-western Poland between the periods 1891–1930 and 1981–2010. The average monthly precipitation totals available for 368 and 245 stations, respectively, are spatially interpolated and processed to calculate maps of differences and pluvial continentality indices for both periods. The maps are analysed against changes in atmospheric circulation and take into account the potential role of the mountain barrier of the Sudetes. The main findings are (1) winter totals generally increased in conjunction with a higher frequency of zonal circulation; it is more pronounced in the upper parts of the Sudetes due to orographic effects; (2) a decreased frequency of zonal circulation together with an increased frequency of southern flows has likely led to the reduction of precipitation in spring and autumn. These changes have led to a significant modification of the region’s pluvial regime, mostly by decreasing continentality features (especially in the Sudetes and the western lowlands). In addition, the strong sheltering influence of the mountain barrier is observed, driving the preservation or even the enhancement of the continental pluvial characteristics in the north-eastern to eastern foregrounds of the Sudetes. This leads to the conclusion that in areas where long-term observed trends or future projections of precipitation are ambiguous, there may occur significant modifications in regional characteristics, especially as a result of changes in atmospheric circulation modified by local orography.

Increasing Water Resources Availability Under Climate Change

The attention to the water scarcity problems caused by climate change is paid in the Czech Republic since 1990's. Increasing daily mean temperature, changes in distribution of precipitation and earlier snow melt lead to insufficient recharge of the groundwater reserves and in turn to a decrease of baseflow component of total runoff. Water streams are then more sensitive to drying during dry periods, which has far-reaching impacts on water stream ecology and the availability of water for the users.The paper describes objectives, methods and first year results of the project ‘Increasing water resources availability in selected regions of Karlovy Vary district’. The project is focused on the region that faces long term problems with water availability. The objective is a development and verification of methods for proposal of adaptation measures to increase the reliability of water resources in the periods of water stress.

1980年代後半の全国的な冬季昇温に伴う降水量分布の変化と気圧配置型の影響

Changes in precipitation distribution associated with a surface temperature rise in the late 1980s, which accompanied a climatic regime shift, are investigated using Automated Meteorological Data Acquisition System (AMeDAS) data of the Japan Meteorological Agency, and their relations with the variability of surface pressure patterns are revealed. After the temperature rise, the frequency of winter monsoon pressure patterns did not decrease. According to the classification of pressure patterns, long-term variations of surface pressure pattern frequencies showed negative relations between the winter monsoon and high-pressure patterns before 1992, which subsequently changed to the negative relations between the winter monsoon and traveling low-pressure systems. After the temperature rise, in years when low-pressure patterns prevailed, precipitation increases were observed in western Japan due to low-pressure systems traveling over the Pacific coast, and in wider areas from central Japan to Kyusyu areas due to low-pressure systems traveling over the Sea of Japan. Recently, the frequency of stationary front patterns has been increasing with precipitation increasing in the Setouchi area of western Japan. In years with a warm winter, precipitation increased in wider areas of the Pacific coast to inland areas of central Japan. In cold winters, low-pressure systems traveling over the Pacific coast decreased precipitation in central to western Japan. However, after a temperature rise, low-pressure systems traveling over the Sea of Japan decreased precipitation at the coast of the sea of Japan from central Japan to Hokkaido.

Evidence of viral dissemination and seasonality in a Mediterranean river catchment: Implications for water pollution management

Conventional wastewater treatment does not completely remove and/or inactive viruses; consequently, viruses excreted by the population can be detected in the environment. This study was undertaken to investigate the distribution and seasonality of human viruses and faecal indicator bacteria (FIB) in a river catchment located in a typical Mediterranean climate region and to discuss future trends in relation to climate change. Sample matrices included river water, untreated and treated wastewater from a wastewater treatment plant within the catchment area, and seawater from potentially impacted bathing water. Five viruses were analysed in the study. Human adenovirus (HAdV) and JC polyomavirus (JCPyV) were analysed as indicators of human faecal contamination of human pathogens; both were reported in urban wastewater (mean values of 106 and 105 GC/L, respectively), river water (103 and 102 GC/L) and seawater (102 and 101 GC/L). Human Merkel Cell polyomavirus (MCPyV), which is associated with Merkel Cell carcinoma, was detected in 75% of the raw wastewater samples (31/37) and quantified by a newly developed quantitative polymerase chain reaction (qPCR) assay with mean concentrations of 104 GC/L. This virus is related to skin cancer in susceptible individuals and was found in 29% and 18% of river water and seawater samples, respectively. Seasonality was only observed for norovirus genogroup II (NoV GGII), which was more abundant in cold months with levels up to 104 GC/L in river water. Human hepatitis E virus (HEV) was detected in 13.5% of the wastewater samples when analysed by nested PCR (nPCR). Secondary biological treatment (i.e., activated sludge) and tertiary sewage disinfection including chlorination, flocculation and UV radiation removed between 2.22 and 4.52 log10 of the viral concentrations. Climate projections for the Mediterranean climate areas and the selected river catchment estimate general warming and changes in precipitation distribution. Persistent decreases in precipitation during summer can lead to a higher presence of human viruses because river and sea water present the highest viral concentrations during warmer months. In a global context, wastewater management will be the key to preventing environmental dispersion of human faecal pathogens in future climate change scenarios.

Atmospheric re-organization during Marine Isotope Stage 3 over the North American continent: sedimentological and mineralogical evidence from the Gulf of Mexico

Mineralogical and sedimentological records from the Gulf of Mexico (GOM) reveal major changes in the terrigenous particles provenance during the Marine Isotopic Stage 3 (MIS3) that likely resulted from modifications of the environmental conditions – including glacial activity and precipitation distribution – over the North American continent. The southeastern margin of the Laurentide Ice Sheet (LIS) was active throughout the entire MIS3, whereas the southwestern margin contributed to short-term meltwater events only during late MIS3. Some of the major mineralogical changes cannot be attributed to glacial activity but rather result from the changes in precipitation distribution. Combining sedimentological records from the GOM with previously published climate-related archives from the North American continent allows the reconstruction of two main schematic patterns of moisture inflow and precipitation distribution that may have prevailed during MIS3. Meltwater discharges contribute to modifying the LIS configuration and the GOM hydrological properties, ultimately affecting large-scale oceanic circulation and may have influenced atmospheric re-organizations although the insolation variation rate appears to be the main driver of the system.

Carbon and nitrogen stock and fluxes in coastal Atlantic Forest of southeast Brazil: potential impacts of climate change on biogeochemical functioning

The Atlantic Forest is one of the most important biomes of Brazil. Originally covering approximately 1.5 million of km², today this area has been reduced to 12% of its original size. Climate changes may alter the structure and the functioning of this tropical forest. Here we explore how increases in temperature and changes in precipitation distribution could affect dynamics of carbon and nitrogen in coastal Atlantic Forest of the southeast region of Brazil The main conclusion of this article is that the coastal Atlantic Forest has high stocks of carbon and nitrogen above ground, and especially, below ground. An increase in temperature may transform these forests from important carbon sinks to carbon sources by increasing loss of carbon and nitrogen to the atmosphere. However, this conclusion should be viewed with caution because it is based on limited information. Therefore, more studies are urgently needed to enable us to make more accurate predictions.

The effect of size and distribution of rod-shaped precipitates on the strength and ductility of a Mg–Zn alloy

We report on a quantitative investigation into the effect of size and distribution of rod-shaped β1′ precipitates on strength and ductility of a Mg–Zn alloy. Despite precipitation strengthening being crucial for the practical application of magnesium alloys this study represents the first systematic examination of the effect of controlled deformation on the precipitate size distribution and the resulting strength and ductility of a magnesium alloy. Pre-ageing deformation was used to obtain various distributions of rod-shaped β1′ precipitates through heterogeneous nucleation. Alloys were extruded to obtain a texture so as to avoid formation of twins and thus to ensure that dislocations were the primary nucleation site. Pre-ageing strain refined precipitate length and diameter, with average length reduced from 440 nm to 60 nm and diameter from 14 nm to 9 nm. Interparticle spacings were measured from micrographs and indicated some inhomogeneity in the precipitate distribution. The yield stress of the alloy increased from 273 MPa to 309 MPa. The yield stress increased linearly as a function of reciprocal interparticle spacing, but at a lower rate than predicted for Orowan strengthening. Pre-ageing deformation also resulted in a significant loss of ductility (from 17% to 6% elongation). Both true strain at failure and uniform elongation showed a linear relationship with particle spacing, in agreement with models for the accumulation of dislocations around non-deforming obstacles. Samples subjected to 3% pre-ageing deformation showed a substantially increased ageing response compared to non-deformed material; however, additional deformation (to 5% strain) resulted in only modest changes in precipitate distribution and mechanical properties.

What would happen to barley production in Finland if global warming exceeded 4 °C? A model-based assessment

In research to date, projected climate change has been considered to be beneficial for agriculture under Nordic conditions, where crop production is mainly limited by low temperatures resulting in short growing seasons. However, with the rapid increases in global mean temperature implied at the high end of the uncertainty range of current projections, which are typically amplified at high latitudes, conditions for crop production could change so dramatically that yields would be reduced, even accounting for the positive effects of CO 2 fertilization. In this study, we used the WOFOST crop growth simulation model to examine crop yield responses to a set of plausible scenarios of climate change for Finland up to 2100, including some that exceed 4 °C global mean temperature increase relative to pre-industrial. We selected spring barley ( Hordeum vulgare L.) as an indicator crop and calculated water-limited yields for two Finnish locations, Jokioinen and Jyväskylä and for a clay and a sandy soil. Scenarios included systematic increases in temperatures, changes in precipitation distribution and altered daily climatic variability using the M&Rfi weather generator. We also examined the effectiveness of a few adaptation options, such as shifts in sowing dates and hypothetical new crop cultivars. Increasing temperature reduced total growth duration and yield considerably, even with adjusted earlier sowing. A reduced number of rainy days had marked negative effects only in combination with increases in temperature of 4 °C or greater, leading to distinctly higher yield losses on the sandy soil than on the clay. Prolonged dry spells clearly increased yield variability. For scenarios with temperature increases of +6 °C and + 7°C, yield losses at Jokioinen were highest; losses at Jyväskylä were generally less pronounced. Neither CO 2 fertilization nor adjusted sowing could compensate the yield losses from temperature changes exceeding +4 °C. On clay soils, yield loss could be compensated by new cultivars. For sandy soils even with new cultivars, there would be yield loss at temperature increases exceeding +3 °C. It can be concluded that the positive effects of climate warming and elevated CO 2 concentrations on cereal production at high latitudes are likely to be reversed at temperature increases exceeding 4 °C, with a high risk of marked yield loss. Only plant breeding efforts aimed at increasing yield potential jointly with drought resistance and adjusted agronomic practices, such as sowing, and adequate nitrogen fertilizer management and plant protection, holds a prospect of partly restoring yield levels and reducing the risks of yield shortfall.

A 14,000-year diatom oxygen isotope record from the Romanian South Carpathians reflect changes in the seasonal distribution of precipitation and temperature

Oxygen isotope records from lacustrine sediments have the potential to reflect short-term and long-term changes in temperature, seasonal changes in the distribution of precipitation and changes in lake water budget determined by the evaporation to inflow ratio. This proxy has widely been used in the Alps and NW Europe to provide high-resolution temperature or evaporation records, but similar studies in the Carpathians are missing. Here we provide a continuous Lateglacial and Holocene record of diatom silica oxygen isotope changes (δ 18 O DIAT ) in a subalpine lake sediment sequence coming from the northern flank of the Retezat Mts (Taul dintre Brazi, TDB, 1740 m a.s.l.).

Institutional resilience and climate variability in international water treaties: the Jordan River Basin as “proof-of-concept”

Climate-driven changes in precipitation distribution have implications for the long-term sustainability of international water-sharing and hydropower agreements. This research analyses water allocation methods, estimates the resilience of existing water supply arrangements, and examines the role of modified institutional arrangements in addressing possible vulnerabilities in transboundary basins. Specifically, we analyse the resilience of the 1994 Israel–Jordan Treaty of Peace during climate extremes. While the absence of a drought provision in the Treaty left Jordan and Israel vulnerable to drought-induced conflict, the Treaty did establish a Joint Water Committee (JWC) to resolve conflicts without making permanent amendments to the original agreement. During the drought of 1998/99, Israeli and Jordanian members of the JWC brokered a temporary arrangement to modify allocations in order to reflect water availability. Even though water availability restricted the parties from fulfilling Treaty obligations, the institutional arrangement created by the Treaty enabled the parties to peacefully cooperate in time of severe drought. Citation Odom, O. & Wolf, A. T. (2011) Institutional resilience and climate variability in international water treaties: the Jordan River Basin as “proof-of-concept”. Hydrol. Sci. J. 56(4), 703–710.