Dry Days Research Articles

Trends of temperature and precipitation extreme indices in north Maharashtra

Climate change has intensified extreme weather events, posing major challenges to agriculture-dependent regions like Northern Maharashtra. This study analyzed temperature and precipitation extremes across five districts—Nashik, Dhule, Nandurbar, Jalgaon and Ahmednagar using data from 1982 to 2022 with the help of RClimDex model. Key temperature indices, including tropical nights (TR25), warm days (TX90p), and frost days (FD13) showed an increase in warm events and a decline in cool nights and frost days. Reduced diurnal temperature range (DTR) indicated less nighttime cooling, consistent with global warming. For precipitation, extreme rainfall events are rising as indicated by the maximum 1-day precipitation (Rx1day), while consecutive dry days (CDD) are shortening. These shifts heighten risks such as crop heat stress, altered growing seasons, soil erosion, and water management challenges. The study underscores the urgent need for adaptive agricultural strategies, improved irrigation, and early warning systems to mitigate the impacts of climate change and enhance resilience in Northern Maharashtra.

Impact of Bulk Nanobubble Water on a TiO2 Solid Surface: A Case Study for Medical Implants.

In the field of medical implants, enhancing the wettability of artificial surfaces is crucial for improving biocompatibility. This study investigates the potential of ozone nanobubble water, an aqueous solution known for its strong oxidizing and sterilizing properties, to modify the surface of titanium dental implants. By immersing the implants in ozone nanobubble water for ∼10 min, we observed a significant transformation of their surface characteristics. Implant surfaces that had become hydrophobic over time, likely due to organic contaminants, became superhydrophilic, exhibiting a contact angle near zero. Fresh implant material is initially hydrophilic but becomes hydrophobic within a few days of drying. In sharp contrast, the hydrophilicity induced by ozone nanobubble water treatment persisted for more than one month. This durability suggests not only the removal of organic matter through cleaning but also a substantial alteration in the surface properties of the implants. The generation of ozone nanobubble water involved releasing ozone microbubbles into an aqueous solution containing trace amounts of iron and manganese, resulting in spherical particles with an average diameter of ∼10 nm. These particles could be bulk nanobubbles, a stabilized gas body surrounded by a solid shell composed of iron hydroxide. Termed "nanoshells" in our previous study, these particles demonstrated exceptional dispersibility without the need for stabilizing agents such as surfactants or capping agents, attributed to their inherent high wettability. The sustained hydrophilicity of the implant surfaces might be attributed to the adherence of these hydrophilic nanoshells to the implant's surface. This study highlights the potential of ozone nanobubble water for long-term surface modification of dental implants, offering a promising avenue for enhancing implant biocompatibility.

Decadal Variability of Dry Days in Central Chile

Decadal Variability of Dry Days in Central Chile

Spatial distribution patterns and hotspots of extreme agro-climatic resources in the Horro Guduru Wollega Zone, Northwestern Ethiopia.

Extreme temperatures and rainfall influence crop yields, soil health, and natural ecosystems. This study examined the extent of extreme agro-climatic factors in Northwestern Ethiopia, with a focus on identifying vulnerability hotspots. Rainfall and temperature data from 1982 to 2022 were collected from eight meteorological stations of the Ethiopian Meteorological Institute, and missing values and outliers were corrected using imputation and Z-scores. ClimPact2 software extracted agro-climatic indicators, and trend analyses were performed using the Mann-Kendall test and Sen's slope. Consecutive dry days (CDD) ranged from 27 in Fincha'a to 57 in Obora, with Obora showing an annual increase of 2.033days. Consecutive wet days (CWD) varied from 12 in Obora to 138 in Fincha'a. A positive trend in the warmest maximum temperatures (TXx) and a negative trend in the cold night index (TN10P) were observed. The Amuru District recorded the highest vulnerability index at 61, with most districts ranging from 42 to 60. These variations may significantly affect agriculture and water management in the region, necessitating the adoption of heat-tolerant crops and improved irrigation practices to enhance climate resilience.

Modeling soil acidity (pH) dynamics under extreme agroclimatic conditions in Horro Guduru Wallaga Zone, northwestern Ethiopia.

Soil plays a critical role in nutrient availability, microbial activity, and fertility in agriculture. However, the effects of agroclimatic conditions on soil pH are not well understood, particularly in the Horro Guduru Zone of Ethiopia. This study aimed to investigate the soil pH under extremely wet and dry conditions across 3 shared socioeconomic pathway (SSP) scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Baseline agroclimatic data (1981-2010) and future projections (2041-2070) were obtained from the European Commission Climate Change Services. Soil pH data at a 250m resolution were extracted from the FAO-UNESCO global soil map. Missing values, multicollinearity, and outliers were addressed before modeling. Predictive models, including neural networks, generalized regression, and bootstrap forests, were validated, with the generalized regression model showing the best performance. The results indicate that soil pH decreases under consecutive dry‒wet conditions and increases with increasing maximum day temperatures across all scenarios. Soil pH is significantly influenced by the number of consecutive dry days, consecutive wet days, and maximum day temperature. The SSP1-2.6 and SSP2-4.5 scenarios resulted in improved pH levels, whereas SSP5-8.5 led to a decrease in soil pH, averaging 5.79 and decreasing to 5.54. These findings suggest that under SSP5-8.5, soil health and farming productivity may be compromised. This study emphasizes the need to adjust soil management practices based on prevailing climatic conditions to ensure soil health and agricultural sustainability.

The significance of biowaste drying analysis as a key pre-treatment for transforming it into a sustainable biomass feedstock.

The objective of this study is to investigate the drying kinetics of fruit and vegetable peel biowaste using a sustainable technique as a key-pretreatment for its conversion into useful feedstock. Biowaste represents a missed potential source of bioenergy and bioproducts, but moisture removal is required, and conventional drying methods are expensive since they require great quantity of energy supplied, almost always, by a non-renewable energy. In this study six batches with the same quantity of biowaste, and heterogeneous physical composition were dried under open-sun conditions. We evaluated the influence of the interaction between drying area and the initial moisture content on drying rate. Eight semi-theoretical models were fitted using Levenberg-Marquardt algorithm to predict drying rate, and their accuracy was assessed through goodness-of-fit tests. Maximum moisture content to preserve biomass (10%) was reached on 5th day and the equilibrium on 16th day of drying. According to goodness-of-fit test (R 2=0.999, χ 2=4.666×10-5, RMSE = 0.00683) the best model to predict drying rate was Two-term model. The mathematical model obtained from Fick's second law is reliable to predict drying kinetics, R2 (0.9648±0.0106); despite the variation between drying area and initial moisture content. Kruskal-Wallis test showed that drying rates between batches are not significantly different (p=0.639; 0.05); nor effective diffusion coefficient (D eff =4.97×10-11±0.3491×10-11), (p=0.723; 0.05). The study of drying kinetics is crucial for selecting the optimal biowaste treatment based on its generation context. This could enable its use as feedstock for bioproduct or bioenergy production, thereby reducing waste accumulation in landfills and environmental impact.

Evaluation of stormwater runoff pollutant distributions combined with land-use information in a regional karst aquifer in Texas, USA.

Fast urbanization can result in significant stormwater runoff pollution due to changes in land use. A 3-year study on the distribution and temporal variations of urban water pollutants in stormwater runoff was conducted, with a specific focus on the influence of land-use patterns in the recharge zone of a regional karst aquifer in Texas (Edwards Aquifer). The presence and concentration of various water pollutants including total suspended solids (TSS), total dissolved solids (TDS), nutrients (nitrite, nitrate, ammonia and phosphate), total carbon (TC) and total organic carbon (TOC), oil and grease (O&G), and eight heavy metals (Fe, Mg, Cu, Pb, Zn, Ni, Cr, Cd) were measured in stormwater samples collected from three bioswales. Results show that average TSS in site S1 (598.87mg/L) and S2 (628.69mg/L), COD in site S1 (103.97mg/L), phosphate in sites S1 (1.44mg/L) and S3 (0.65mg/L), and O&G (ranging from 50.63 to 84.32mg/L) in all three sites surpassed the national average (NSQD). While residential areas were identified as the main sources of nutrients, roads and parking lots were associated with heavy metals. Temporal variations indicated the effect of antecedent dry days on the concentrations of TSS and phosphate. Growing seasons as well as pet feces were associated with elevated nitrate concentrations in residential areas. Organic carbon was found overall higher during warmer months, while heavy metals during cooler months. The study also identified specific land-use practices that can be enhanced to mitigate stormwater pollution, such as the implementation of permeable pavements, rain gardens, and stricter waste disposal regulations. The results of this study offer valuable insights for enhancing stormwater management strategies to better mitigate stormwater pollution in urban regions.

Pattern-based assessment of the influence of catchment characteristics on urban stormwater quality

ABSTRACT Use of traditional catchment characteristics and lack of effective separation of catchment characteristics from rainfall characteristics limits the adequate understanding of the actual influences of catchment characteristics on stormwater quality. In this context, this study adopted a pattern-based separation approach to identifying common events from three rainfall clusters of study catchments, where rainfall characteristics for identified common 8, 9 and 36 events are similar, but catchment characteristics are different. This study identified that the locations of pervious surfaces and urban forms are also important catchment characteristics. The contribution of the pervious area to runoff is significant for long durational (cluster 1) and high-intensity (cluster 3) rainfall events associated with low antecedent dry days and initiated at around 35 mm rainfall depth. A catchment having a large impervious area and pervious area located at far distances from the drainage system can contribute more pollutant load at first 10% runoff volume. High socio-economic developed urban form can contribute a high fraction wash-off corresponding to 10–70% runoff volume due to traffic-related behaviour and various anthropogenic activities. The developed knowledge will overcome the shortcomings of lumped characteristics-based treatment design and improve the efficiency of current stormwater treatment system design practices.

Mass Timber Buildings: The associated risks of rainwater exposure during construction in the Portuguese climate

The increase in the number and complexity of wooden buildings creates a series of challenges, like moisture control and management during the construction phase. The risks associated with the direct exposure of timber elements to rain during construction depend on the severity of the climate and the specific details of each project and therefore must be analysed locally. In this context, the results of 16 weeks of moisture content monitorization of Cross Laminated Timber (CLT) floor-wall connection specimens exposed to the outdoors are presented and evaluated. The monitorization demonstrated that end-grain surfaces are the most sensitive to the action and movement of water in CLT and within a few days of exposure to rain reached alarming moisture content (MC>30 %), with water entrapment at the interface between elements, preventing drying in a reasonable time for construction workflow (MC>30 % after 39 days of drying). On the other hand, zones with faster drying exhibited severe physical damage such as delamination and cracks. Additionally, the study evaluates the feasibility of using satellite-obtained meteorological data to develop a degradation risk map (Scheffer Climate Index) for mainland Portugal. The high coefficient of determination (R2 ≥ 0.81) and model efficiency (EF ~ 0.80–0.90) demonstrate the reliability of the data. Finally, two degradation risk maps for mainland Portugal are presented.

Variability of Dry Days and Sequences of Dry Days in the Polish Carpathians in the Period 1986–2020

This study provides a climatological analysis of annual and long-term variability of dry days and sequences of dry days in the Polish Carpathians between 1986 and 2020. The input data for the research was compiled from the daily precipitation totals from 17 meteorological stations and the T. Niedźwiedź catalogue of circulation types over southern Poland. The frequency of sequences of dry days of different duration has been presented. The incidence of long-term periods has been related to the atmospheric circulation. The number of dry days and the averages of both the number and of the duration of sequences of dry days were analysed for the study period. This yielded an average annual number of dry days ranging from 142 to 195 (39–53% of days in a year), depending on the altitude above sea level and longitude. A general pattern emerged in which the number of dry days increased from west to east. At most stations, there were no statistically significant trends with respect to the dry day characteristics analysed. This is an obvious result of high year-to-year variability, which means that only large changes can achieve statistical significance. Dry days have been evidenced to relate to circulation types. The vast majority of dry days are related to anticyclonic systems, particularly the anticyclonic wedge (Ka) and western anticyclonic (Wa) situations. On the other hand, no clear-cut relationship was established between an increase in air temperature and the occurrence of dry days.

Distribution of evapotranspiration components along vertical layers and their controls in dry days of larch plantation in the Liupan Mountains of northwest China

Precise quantification of forest evapotranspiration (ETf) including transpiration from tree (Tt), shrub (Ts), and herb (Th) layers, as well as evaporation from litter (El) and soil (Es) layers, and elucidating their responses to environmental conditions and stand structures are crucial for forest water management in water-limited forests. In this study, we observed the Tt, Ts, Th, El, and Es, reference evapotranspiration (ETo), soil volumetric water content (SWC), litter water content (LWC), leaf area index (LAI) in tree, shrub, and herb layers, and canopy shade (Ksc) from tree layer of the Larix principis-rupprechtii plantation during the dry days from May to October of 2021 and 2022 to elucidate the distribution of evapotranspiration along vertical layers and their environmental and structural determinants. The results indicated that the contributions of Tt, Ts, Th, El, and Es to ETf during the dry days in 2021 (2022) were 42.1 % (44.7 %), 9.2 % (8.1 %), 8.2 % (8.6 %), 15.0 % (13.1 %), and 25.5 % (25.5 %), respectively. Although Tt and Ts demonstrated quadratic relationships with ETo, Th, El, and Es exhibited linear relationships. All ETcs demonstrated a saturated exponential relationship with either SWC or LWC. Furthermore, Tt, Ts, and Th showed a saturated exponential relationship with their respective LAI, whereas El and Es exhibited a cubic relationship with LAI in tree layers. All understory ETcs (Ts, Th, El, and Es) decreased exponentially with the Ksc. The multi-factor models of evapotranspiration component (ETc) from different vertical layers, which coupled the impacts of environmental conditions and vertical structure, were developed, and provided superior accuracy (R2 = 0.78–0.88, NSE = 0.78–0.86, RSME = 0.03–0.16). Such insights deepened the understanding of vertical structural distribution and multi-factor responses of ETcs in forest ecosystems and hold the potential to inform and optimise forest water management strategies.

The added value of using convective-permitting regional climate model simulations to represent cloud band events over South America

Climate science has long explored whether higher resolution regional climate models (RCMs) provide improved simulation of regional climates over global climate models (GCMs). The advent of convective-permitting RCMs (CPRCMs), where sufficiently fine-scale grids allow explicitly resolving rather than parametrising convection, has created a clear distinction between RCM and GCM formulations. This study investigates the simulation of tropical-extratropical (TE) cloud bands in a suite of pan-South America convective-permitting Met Office Unified Model (UM) and Weather Research and Forecasting (WRF) climate simulations. All simulations produce annual cycles in TE cloud band frequency within 10–30% of observed climatology. However, too few cloud band days are simulated during the early summer (Nov–Dec) and too many during the core summer (Jan–Feb). Compared with their parent forcing, CPRCMs simulate more dry days but systematically higher daily rainfall rates, keeping the total rain biases low. During cloud band systems, the CPRCMs correctly reproduced the observed changes in tropical rain rates and their importance to climatology. Circulation analysis suggests that simulated lower subtropical rain rates during cloud bands systems, in contrast to the higher rates in the tropics, are associated with weaker northwesterly moisture flux from the Amazon towards southeast South America, more evident in the CPRCMs. Taken together, the results suggest that CPRCMs tend to be more effective at producing heavy daily rainfall rates than parametrised simulations for a given level of near-surface moist energy. The extent to which this improves or degrades biases present in the parent simulations is strongly region-dependent.

Projected changes in mean climate and extremes from downscaled high-resolution CMIP6 simulations in Australia

High-resolution climate change projections are required to evaluate local and regional climate change impacts. We used CCAM (Conformal Cubic Atmospheric Model) to dynamically downscale CMIP6 GCMs (Global Climate Models) over Australia under three emissions scenarios, producing a set of 60 simulations at a 10 km resolution. Previous work has evaluated the performance of the downscaled models in the historical period. Here, we evaluate the impact of end-of-century climate change in the downscaled CMIP6-CCAM models for mean and extreme climate under three Shared Socioeconomic Pathways (SSP126, 245 and 370). We find the changes in mean climate are in general similar in the host CMIP6 and downscaled models. For extreme temperature, we find that extreme maximum temperatures (TXx) increase by 3.4 °C, while extreme minimum temperatures (TNn) warm by 3.0 °C. Extreme precipitation generally increases in summer and decreases in winter; however, there is a large amount of inter-model variation in the location and magnitude of change. Consecutive dry days also decrease in most areas in Austral summer and increase in Austral winter. Heatwaves become more frequent and hotter by the end of the century. These results suggest a hotter, wetter Austral summer, with longer, more frequent and more intense heatwaves, and a hotter and drier Austral winter in most areas. This dataset provides useful new high-resolution information on how climate change is likely to impact Australia, which will be a valuable resource to underpin local adaptation responses to future impacts.

Research on short-term optimization and scheduling of multi-energy complementary systems based on forecast scenario dynamic correction

The inherent unpredictability and instability of renewable energy sources, such as wind and solar power, hinder the precise execution of power generation plans in complementary systems, posing significant challenges to their integration into power grids. Therefore, this study proposes a dynamic correction method for wind and solar output forecast scenarios in the short-term scheduling of wind-solar-hydro complementary systems. The method utilizes statistical analysis of forecast errors in wind and solar power outputs to characterize uncertainty patterns across different forecast levels and constructs a typical forecast scenario set based on single-day forecasts. This approach probabilistically models each scenario according to the temporal migration patterns of wind and solar power outputs and develops a neural network-based dynamic correction fusion model to refine the forecasts. Application of this method in a case study of the Yalong River Basin demonstrated that, after applying dynamic correction to the forecast scenarios, the mean absolute error in total wind and solar output predictions during the wet and dry seasons was reduced by 50.73 % and 47.95 %, respectively. Additionally, the dynamic correction reduced the maximum residual load on typical wet and dry days by 82.70 % and 62.37 %, respectively, and decreased the total intraday residual electricity by 91.17 % and 73.24 %, compared to single-day forecasts. The study concludes that the proposed dynamic correction method enhances power system stability and improves power generation efficiency and reliability.

Harvest and trade of wild edible russula griseocarnosa in North Vietnam

This study examines the harvest and trade of wild edible Russula griseocarnosa in north Vietnam. Russula griseocarnosa is an edible forest mushroom, but there is no reliable information on harvesting practices and trade in this species in Vietnam. This study aims to provide ethnomycological and marketing knowledge for this mushroom. Semi-structured interviews were conducted with mushroom collectors and traders over 2 years; harvest yields were obtained from local officials; and policy settings were sought from forest managers. About 85% of mushroom collectors were women of the Dao, Lo Ursula, Muong, Nung, Mong, San Chi, San Diu, and Tay ethnicities. The collecting season was bimodal, with the wet season beginning (May) and ending (September). The traders were Hoa, Kinh, Nung and Tay, and 57% were women. Fresh mushrooms sold for 9.1-10.5 US$/kg on dry days and 7.0-7.9 US$/kg on wet days. The best grade of dried product fetched 70.4-83.3 US$/kg. A number of interim policies have been established to encourage local people to protect forests and to help create a sustainable edible wild mushroom market. Our study provides the first detailed account of the role of edible wild mushrooms in northeast Vietnam, and this will inform the co-development of rural livelihood and sustainable forest management plans.

Projected changes in wet and dry extremes in the CMIP6 multi-model ensemble over the IGAD region of Eastern Africa

Wet and dry days, as well as wet and dry spells, are crucial pieces of information for rain-fed agriculture, food security, and numerous socioeconomic activities in East Africa. This study examines the projected changes in wet/dry days and wet/dry spells using data from the Multi-Model Ensemble (MME) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6). Statistical criteria and thresholds are used to project the changes in wet and dry days, as well as wet and dry spells, under the shared socioeconomic pathways (SSP) scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) for the annual, March–May (MAM), June–September (JJAS), and October-December (OND) seasons. The analysis indicates that the CMIP6 models generally overestimate the number of wet days (wet spells) across all seasons and scenarios at the 1 mm threshold. A projected 10–20% increase in total rainfall over the IGAD region is driven by an increase in rainfall intensity and the number of wet days under all scenarios during the near (2021–2050) and far (2071–2100) futures. A decrease in wet days and spells (increase in dry days and spells) is projected over South Sudan in JJAS, while an increase in wet spells is projected over Kenya, Somalia, and Sudan in OND during the near and far future compared to the baseline period. By the end of the century, wet days are projected to increase by approximately 20–30%, and dry spells are projected to decrease by 10–20% under the SSP1-2.6 and SSP5–8.5 scenarios. The EnsMean 10 CMIP6 tends to smooth out the extremes (wet or dry biases), creating a result that may appear more accurate but does not reflect the extremes or variations projected by individual models over South Sudan, Uganda, Kenya and Ethiopia. The projected patterns of wet and dry spells under SSP1-2.6 highlight the importance of mitigation efforts to limit temperature rise to below 1.5°. It is necessary to model how shifts in extreme dry and wet conditions will likely affect climate-sensitive sectors, such as agriculture and food security, in order to make well-informed decisions.

Bias correction of daily precipitation from climate models, using the Q‐GAM method

AbstractClimate models are useful tools for analyzing historical and projecting future climate conditions. However, the model results tend to differ systematically from observations, particularly for parameters with complex spatial and temporal distributions such as precipitation. A combination of quantile mapping and generalized additive models (GAMs) is presented and proposed as a new method (Q‐GAM) for the bias correction of daily precipitation. Q‐GAM is demonstrated by using data from five European stations with different climate characteristics. For each station, the closest continental grid point of a EURO‐CORDEX climate model was selected for bias correction. A bootstrapping experiment is presented with over 1000 repetitions of randomly splitting the historical period 1981 to 2005 into a calibration and evaluation period. The results for all stations reveal that Q‐GAM is a straightforward, accurate and computationally efficient method for the bias correction of precipitation. In particular, the method improves the frequency of dry days and the total annual rainfall amount. This outcome is robust across stations with varying climate characteristics and also to the choice of calibration and evaluation periods. Similar results are also obtained for other precipitation characteristics such as the 0.9 and 0.95 quantiles.

Concentrated solar thermoelectric power generator equipped with a novel ultrathin wet porous membrane cooling technique; experimental study

One side of any thermoelectric power generator (TEG) is hot while the other side should always stay cold. The higher the temperature difference, the greater the power generation. This paper offers a particular ultrathin wet porous membrane (UWPM) as a new cooling method for a solar thermoelectric power generator. According to the graphical abstract, the membrane has a capillary-wicking feature on one side, making it possible to be soaked spontaneously and create a steady thin water film on the ceramic layer of the thermoelectric, thereby serving as an energy-free, enthalpy of vaporization-based cooling method (surface vaporization). Interestingly, water is replenished spontaneously as long as the water exists in the tank. The suggested mechanism is tested under two weather conditions: one hot, dry day (ambient air around 40 °C) and one moderate day (ambient air around 30 °C), with different air speeds between 1.5 and 4.5 m/s to simulate different wind speeds in real applications. Power, cold side surface temperature, maximum conversion efficiency, etc., are measured, evaluated, discussed, and compared with the common fin-pin heatsink/fan thermal management tool. Notably, the implementation of the UWPM demonstrates a substantial enhancement in thermoelectric generator performance. It is noted that the lowest temperature that can be obtained through vaporization can be colder than ambient air temperature, approaching the wet-bulb temperature. The UWPM keeps the cold side temperature up to 10 degrees colder than that achieved in the heatsink method. This is why the generated power by the TEG is around 2.5 times higher when utilizing the UWPM. Furthermore, unlike the fin-pin heatsink (FPH) thermal management tool, warmer weather conditions do not diminish the cooling quality of the UWPM method. Indeed, the cold side temperature on a hot, dry day is almost the same as that on a moderate day using the UWPM technique. This is because hot ambient temperature induces greater and easier vaporization, leading to a higher cooling effect.

Future changes in agrometeorological extremes in the southern Mediterranean region: When and where will they affect croplands and wheatlands?

Climate change and extremes are increasingly threatening food security, especially in the Global South. Here, we examine how croplands and wheatlands of the southern Mediterranean region could be affected by projected changes in agrometeorological extremes over the 21st century. We use 17 bias-corrected climate models from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) to identify potential trends and assess the time of emergence of significant changes in agrometeorological extremes under the Shared Socioeconomic Pathway (SSP3–7.0). We note that simulated historical trends in agrometeorological extremes closely match observed trends, here derived from ERA5land, over croplands. Our analysis of CMIP6 projected scenarios reveals a consistent rise in heat intensity, drought intensity, and the frequency of compound dry and hot (D5/H95) days. While a reduction in frost intensity, combined with fewer wet and cold (W95/C5) and dry and cold (D5/C5) events offer some mitigation potential, concerns about water scarcity due to heightened heat and drought stresses may overshadow these benefits. These changes in agrometeorological extremes are projected to emerge in the near- and mid-term future (by 2030 and 2050). We also note that the projected decreases in cold extremes affect smaller agricultural regions than the increases in extreme heat. We find higher likelihoods of negative agrometeorological impacts over croplands and wheatlands throughout the 21st century, which could significantly challenge crop yields and agricultural sustainability. Without proactive adaptation and mitigation strategies, food security could come increasingly under threat in a changing climate in the southern Mediterranean region.

Spatial and temporal analysis and trends of extreme precipitation over the Mississippi River Basin, USA during 1988–2017

Study regionMississippi River Basin. Study focusUsing daily precipitation records of 769 meteorological stations over the Mississippi River Basin (MRB), the spatial-temporal variability and trend of nine extreme precipitation indices were estimated and statistically assessed using the Mann-Kendall test. Factors likely to influence the spatial pattern and trends of precipitation extremes indices were also checked. New hydrological insights for the regionThe spatial pattern of the extreme precipitation indices exhibits a southeast to Northwest dipole, with the maximum values recorded over the southeastern part of the domain (exception being for Consecutive Dry Days, CDD which shows otherwise) driven by the southerly moisture transport toward the southeast. The spatial pattern of the extreme precipitation is controlled by the topography. The results also show that, on average, almost all the indices (except CDD) exhibit an increasing trend. The total wet day precipitation exhibits a significant increasing trend. Spatially, most of the significant increasing (decreasing) trends of the extreme's precipitation-except CDD- are located over the Upper (South) MRB where there is a significant sign toward cooling (warming) conditions. This supports the view that changing climate towards warming (cooling) conditions is significantly affecting precipitations extremes over the MRB. The relationships between large-scale teleconnections and extreme precipitation show that Pacific North America significantly increases (decreases) frequency and intensity indices over the Northwest (southeast) MRB, whereas the Pacific Decadal Oscillation does increase the frequency and intensity indices over the southeast. El Niño Southern Oscillation significantly increases the frequency and intensity indices over the entire MRB, with consequences to infrastructure failures, increasing vulnerable populations, risk zones and relocations populations.