Precipitation Patterns Research Articles

Transitions between Chinese dynasties influenced by spatial-patterned precipitation

Past studies have often associated the transitions of Chinese dynasties with nationwide climate change, overlooking significant spatial heterogeneity in precipitation anomalies across China. Historical changes in spatial precipitation patterns in response to Asian monsoon variability and their societal impact have not been fully explored. In this study, we present a new extended annual laminated speleothem record from central China covering the last 2000 years. By integrating paleoclimatic data from northern and southern China, we reconstructed the history of spatial precipitation patterns dominated by tripole and dipole patterns over the Common Era. Our analysis revealed that although the relationship between the monsoon and precipitation patterns was non-stationary, the positive phases of both patterns occurred more frequently during periods of monsoon weakening on multidecadal to multicentennial timescales. Moreover, the phase and intensity of these precipitation patterns varied across different intervals during the Chinese dynasties. Notably, transitions of unified dynasties often coincide with the simultaneous occurrence of the positive phases of both patterns on multidecadal timescales. This phase configuration of the patterns aligns with prolonged droughts in Eastern China, coinciding with historical records of reduced grain harvests and economic decline. Our findings highlight that historical changes in spatial configuration, rather than the nationwide synchronicity of precipitation anomalies, play a crucial role in Chinese dynastic transitions.

Understanding precipitation concentration changes, driving factors, and responses to global warming across mainland China

Global warming has increased the frequency and intensity of extreme precipitation events, leading to significant changes in temporal precipitation patterns. These temporal irregularities have exacerbated the occurrence of disasters such as droughts, floods, landslides, and mudslides. Despite this, comprehensive insights into precipitation concentration variations, their driving factors, and their relationship with global warming across nine river basins in mainland China remain insufficient. In this study, the CN05.1 gridded daily precipitation dataset from 1961 to 2020 is utilized to calculate the precipitation concentration index (PCI), precipitation concentration degree (PCD), and precipitation concentration period (PCP). Employing Random Forest and correlation analysis, the study address these gaps. The results indicate that: (1) Northern river basins exhibit significant temporal irregularities in precipitation patterns, whereas southern basins show more uniform temporal distributions in mainland China from 1961 to 2020. The decrease in the proportion of summer precipitation and the increase in spring and winter proportions have led to the decline in PCI across mainland China over the past sixty years. Additionally, the increase in moderately heavy and heavy rainfall events has caused more dispersed daily precipitation, decreasing PCD. (2) The primary factors influencing PCI and PCD are El Niño-Southern Oscillation (ENSO), South mainland China Sea Summer Monsoon Index (SCSSMI), and Arctic Oscillation (AO). PCI, PCD, and PCP are positively correlated with latitude and altitude in mainland China, while coastal basins show a significant negative correlation with longitude. (3) PCI, PCD, and PCP exhibit negative responses to global warming, with some basins experiencing a reduction in precipitation concentration of over 10 % per 1 K temperature rise from 1961 to 2020. Light precipitation frequency shows a negative response, whereas intense precipitation frequency displays a positive response. For precipitation exceeding the 99th percentile, some basins demonstrate response rates exceeding 20 %/K. These findings contribute to a deeper understanding of precipitation concentration dynamics in mainland China and offer scientific basis for mitigating droughts, floods, and managing water resources.

Role of pumped hydro storage plants for flood control

Climate change has intensified precipitation patterns and led to more frequent and severe flooding in many locations worldwide. This paper investigates the role of pumped hydro storage (PHS) plants in mitigating floods in Rio Grande do Sul, Brazil. PHS plants can enhance basin water storage, allowing conventional reservoir dam (CRD) to focus on flood control. The paper also suggests the construction of hybrid PHS plants that can be used to store energy during normal operation and be used to pump water during flood events. The results compare the floodwater volume in Guaíba Lake and Patos Lagoon (27 km3) to the 13 km3 displacement capacity of four proposed PHS projects, which could have reduced the total flood level of the Guaiba Lake from 5.33 m to 3.5 m. This would cost 2.7 billion USD, which is similar to the costs of the impact resulted from the flood in May 2024. This infrastructure would significantly reduce the impact of the floods and make the state of Rio Grande do Sul more resilient to climate change in the future. By analyzing the flood water storage capacity required and the storage and pump capacity provided by these solutions, the study aims to prevent future floods and mitigate climate change impacts in the region.

Dynamics of sediment-associated nitrogen export from intermittent streams in subtropical forests of southeast China

The significance of intermittent streams in nutrient loss within forest ecosystems is becoming increasingly critical due to changes in precipitation patterns associated with global climate change. However, few studies have focused on nutrient export from intermittent streams. We conducted continuous sediment collection from intermittent streams from March 2022 to February 2023 to investigate the export pattern and mechanism of sediment-associated nitrogen (N) from intermittent streams of different forest types (composed forest of Castanopsis carlesii (Cas. carlesii) and Cunninghamia lanceolata (C. lanceolata) forests, compared to Cas. carlesii forests). We measured the N concentrations and calculated the export amounts of four common forms of N associated with sediments: total N (TN), dissolved N (DN), nitrate, and ammonia. Our results showed that (1) the annual average exports of TN, DN, nitrate, and ammonia associated with sediments from intermittent streams from both forest types were 273, 1.62, 0.26, and 0.84 kg·ha-1, respectively; (2) N export was significantly higher in composite forests of Cas. carlesii and C. lanceolata, compared to Cas. carlesii forests; (3) stream sediment export amount positively affected N export both in composite forests and Cas. carlesii forests; and (4) N export was also controlled by rainfall amount and stream characteristics. Our study quantified sediment-associated N export from intermittent streams among different subtropical forest types, which will enhance our understanding of N dynamics associated with stream hydrological processes in subtropical forests.

Cross-Seasonal Effect on Tropical Pacific Precipitation: Implication of South Pacific Quadrupole Simulation in CMIP6

Abstract The tropical Pacific convergence zone plays a crucial role in the global climate system. Previous research studies emphasized the cross-seasonal influence of the South Pacific quadrupole (SPQ) mode on the tropical Pacific climate. This study assesses the relationship between austral summer SPQ and austral winter tropical precipitation in phase 6 of the Coupled Model Intercomparison Project (CMIP6) models. The analysis emphasizes the historical experiments conducted within this time frame, spanning from 1979 to 2014. Our findings reveal that the SPQ is accurately represented in all CMIP6 models, but the connection between SPQ and precipitation is inadequately simulated in most models. To investigate the reasons behind these intermodel differences in reproducing SPQ-related processes, we categorize models into two groups. The comparisons demonstrate that the fidelity of model simulations in replicating the SPQ–tropical precipitation relationship hinges significantly on their capacity to reproduce the positive wind–evaporation–sea surface temperature (WES; SST) feedback over both the southwestern Pacific (25°–10°S; 150°E–160°W) and the southeastern Pacific (30°–10°S; 140°–80°W). This positive WES feedback propagates the SPQ signal into the tropics, intensifying the meridional gradient of SST anomaly in the tropical western-central Pacific, which consequently amplifies convection and rainfall in that area. In the group of models that failed to simulate this relationship accurately, the weakened WES feedback can be traced back to biases in wind speed and its variation. Furthermore, this WES feedback establishes a connection between SPQ and El Niño–Southern Oscillation (ENSO). A better rendition of the SPQ–tropical rainfall connection tends to result in a better simulation of the onset of SPQ-related ENSO events. As a result, this study advances our comprehension of extratropical impacts on the tropics, with the potential to enhance the accuracy of tropical climate simulation and prediction. Significance Statement Tropical rainfall plays an important role in the global climate system. Beyond the well-known influence of El Niño–Southern Oscillation (ENSO) on the tropical rainfall, the sea surface temperature (SST) anomaly in the South Pacific has a cross-seasonal impact on the precipitation over the tropical Pacific via air–sea coupled processes. Such SST anomaly pattern shows a quadrupole structure in the extratropical South Pacific, known as the South Pacific quadrupole (SPQ) mode. However, the relationship between SPQ and tropical precipitation remains poorly simulated in most state-of-the-art climate models. One primary reason for this gap between observed and simulated relationships is the underestimation of wind speed and its variation over the south tropical Pacific in these models. This limitation undermines their ability to accurately represent the air–sea interactions that drive tropical precipitation patterns, leading to inaccuracies in simulations. Our study aims to bridge this knowledge gap by enhancing our understanding of the extratropical effects on the tropical Pacific. By exploring the mechanisms underlying the SPQ–precipitation connection, we expect to improve the simulation and prediction capabilities of tropical climate models, thereby enhancing our ability to forecast and adapt to future climatic changes.

Advanced precipitation peak offsets middle growing-season drought in impacting grassland C sink.

Redistribution of precipitation across seasons is a widespread phenomenon affecting dryland ecosystems globally. However, the impacts of shifting seasonal precipitation patterns on carbon (C) cycling and sequestration in dryland ecosystems remain poorly understood. In this study, we conducted a 10-yr (2013-2022) field manipulative experiment that altered the timing of growing-season precipitation peaks in a semi-arid grassland. We found that the delayed precipitation peak suppressed plant growth and thus reduced gross ecosystem productivity, ecosystem respiration, and net ecosystem productivity due to middle growing-season water stress. Surprisingly, shifting more precipitation to the early growing season can advance plant development, increase the dominance of drought-tolerant forbs, and thus compensate for the negative impacts of middle growing-season water stress on ecosystem C cycling, leading to a neutral change in grassland C sink. Our findings indicate that greater precipitation and plant development in spring could act as a crucial mechanism, maintaining plant growth and stabilizing ecosystem C sink. This underscores the urgent need to incorporate precipitation seasonality into Earth system models, which is crucial for improving projections of terrestrial C cycling and sequestration under future climate change scenarios.

Perception of and adjustment to adverse weather events among smallholder coffee farmers in Rwanda

AbstractChanging temperature and precipitation patterns threaten smallholder farmers producing coffee. Adaptation is crucial, and perceiving adverse weather events as a risk is the first step towards it. The study, therefore, investigated the link between smallholder coffee farmers' perception of adverse weather events and their adjustments to them. First, four distinct groups of farmers can be distinguished based on their risk perception of adverse weather events. Results show that farmers' risk perception is connected to changes in the timing of the seasons and the expected amount of precipitation. Most farmers in the sample adjust to the adverse weather events they experience. Results also found that farmers’ risk perception and adjustment decisions are closely linked.

Precipitation Patterns and Their Role in Modulating Nitrous Oxide Emissions from Arid Desert Soil

Nitrous oxide (N2O) ranks as the third most significant greenhouse gas, capable of depleting the ozone layer and posing threats to terrestrial ecosystems. Climate change alters precipitation variability, notably in terms of frequency and magnitude. However, the implications of precipitation variability on N2O emissions and the underlying mechanisms remain inadequately understood. In this study, employing laboratory incubation methods on three representative sandy soil types (sandy soil, shrub soil, and crust soil), we examined the impacts of diverse precipitation levels (5 mm and 10 mm) and frequencies (7 days and 14 days) on N2O emissions from these soil types. This study aims to clarify the complex connections between soil N2O emission fluxes and soil physicochemical properties in the soil environment. Our findings reveal that the N2O emission flux exhibits heightened responsiveness to 5 mm precipitation events and a 14-day precipitation frequency, and compared to other treatments, the 5 mm precipitation and 14-day precipitation frequency treatment resulted in a 20% increase in cumulative nitrous oxide emissions. Consequently, cumulative N2O emissions were notably elevated under the 5 mm precipitation and 14-day precipitation frequency treatments compared to the other experimental conditions. The N2O emission flux in sandy soil displayed a positive correlation with available phosphorus (AP) and a negative correlation with pH, primarily attributed to the exceedingly low AP content in sandy soil. In shrub soil, the soil N2O emission flux exhibited a significant positive correlation with NH4+-N and a negative correlation with NO3−-N. Conversely, no significant correlations were observed between soil N2O emission flux and soil physicochemical properties in crust soil, underscoring the importance of considering plant–soil microbial interactions. Our findings suggest that soil nitrous oxide emissions in arid and semi-arid regions will be particularly responsive to small and frequent rainfall events as precipitation patterns change in the future, primarily due to their soil physicochemical characteristics.

An Extreme Predecessor Rain Event in Central China Amplified by Upper-Level Jet Streak

Abstract A comprehensive study is conducted on a predecessor rain event (PRE) closely associated with the upper-level jet (ULJ) in central China during July 2021, utilizing the Weather Research and Forecasting Model (WRF). The ULJ and precipitation patterns are reasonably reproduced in the control experiment. In the sensitivity experiment (NOULJ), the ULJ is largely suppressed by the piecewise potential vorticity inversion method. The comparison of the two simulations indicates that the ULJ promotes the development of secondary circulation, lower-level jet (LLJ), moisture transport, and atmospheric instability. Synergistic effects among these processes amplify this PRE. The strong updrafts in the precipitation region are closely associated with the inverse secondary circulation that develops on the south side of ULJ entrance. The upper-level mass divergence associated with the ULJ enhances the lower-level convergence, promoting the development of lower-level vorticity and LLJ. The LLJ facilitates moisture transport into the precipitation region and increasing atmospheric instability. In contrast, the precipitation in NOULJ is decreased by 34% due to the weakening of favorable conditions.

Contrasting Precipitation Variations over the Himalayas–Southeastern Tibetan Plateau in Winter: Insights from the Perspectives of Anthropogenic Warming and Arctic Sea Ice Variations

Abstract Climate warming has caused widespread glacier retreat across the Tibetan Plateau (TP), with notable impacts observed in both the western Himalayas and southeastern TP. Remarkably, over the past two decades, the rate of glacier mass loss has remained stable or even declined in the western Himalayas, whereas a contrasting trend of acceleration has been evident in the southeastern TP. Among various factors considered, the contrasting winter precipitation pattern across the Himalayas–southeastern TP stands out as an important contributor to the observed differences in glacier mass balances. However, the underlying mechanisms behind this phenomenon remain unclear. Here, we provide evidence of a noticeable shift in the climate regime due to anthropogenic warming, altering atmospheric circulation patterns. This, in turn, has led to a significant change in the dominant winter precipitation pattern, favoring the observed contrasting glacier mass balances trend in winter. Additionally, the Barents–Kara Sea ice has emerged as a plausible driver of the interannual variability of the contrasting precipitation pattern, acting by exerting force on the atmosphere and stimulating the Rossby wave propagation. Consequently, it led to the opposite vertical motion and alterations in the moisture budget between the western Himalayas and southeastern TP. Thus, it is crucial to consider the unprecedented anthropogenic warming and Arctic Sea ice variations as potential drivers shaping both past and future glacier behaviors within this domain.

Evaluating Wheat Cultivation Potential in Ethiopia Under the Current and Future Climate Change Scenarios

Land suitability analyses are crucial for identifying sustainable areas for agricultural crops and developing appropriate land use strategies. Thus, the present study aims to analyze the current and future land suitability for wheat (Triticum aestivum L.) cultivation in Ethiopia. Twelve variables including soil properties, climate variables, and topographic characteristics were used in the evaluation of land suitability. Statistical methods such as Rotated Empirical Orthogonal Functions (REOF), Coefficient of Variation (CV), correlation, and parametric and non-parametric trend analyses were used to analyze the spatiotemporal variability in current and future climate data and identified significant patterns of variability. For future projections of land suitability and climate, this study employed climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) framework, downscaled using regional climate model version 4.7 (RegCM4.7) under two different Shared Socioeconomic Pathway (SSP) climate scenarios: SSP1 (a lower emission scenario) and SSP5 (a higher emission scenario). Under the current condition, during March, April, and May (MAM), 53.4% of the country was suitable for wheat cultivation while 44.4% was not suitable. In 2050, non-suitable areas for wheat cultivation are expected to increase by 1% and 6.9% during MAM under SSP1 and SSP5 climate scenarios, respectively. Our findings highlight that areas currently suitable for wheat may face challenges in the future due to altered temperature and precipitation patterns, potentially leading to shifts in suitable areas or reduced productivity. This study also found that the suitability of land for wheat cultivation was determined by rainfall amount, temperature, soil type, soil pH, soil organic carbon content, soil nitrogen content, and elevation. This research underscores the critical importance of integrating spatiotemporal climate variability with future projections to comprehensively assess wheat suitability. By elucidating the implications of climate change on wheat cultivation, this study lays the groundwork for developing effective adaptation strategies and actionable recommendations to enhance management practices. The findings support the county’s commitment to refining agricultural land use strategies, increasing wheat production through suitability predictions, and advancing self-sufficiency in wheat production. Additionally, these insights can empower Ethiopia’s agricultural extension services to guide farmers in cultivating wheat in areas identified as highly and moderately suitable, thereby bolstering production in a changing climate.

Impacts of Climate Change: Examining Precipitation, Temperature Anomalies, and Effects on Water Resources in Turkey

Climate change is a significant global issue that affects our everyday lives and water resources. One of the most critical impacts of climate change is on our water resources, which are vital for sustaining life and supporting various ecosystems. Understanding the complex relationship between climate change and water resources is crucial for developing effective mitigation and adaptation strategies. This study aims to investigate the impact of climate change on water resources and to shed light on the importance of addressing this issue. Water is a limited resource, and its availability and quality directly affect human well-being, agriculture, energy production, and ecosystem health. However, climate change alters the patterns and dynamics of precipitation, temperature, and evaporation, leading to significant changes in water availability and distribution. Increasing global temperatures cause glaciers and ice caps to melt, progressively depleting freshwater resources. Moreover, changing precipitation patterns are leading to more frequent and severe droughts in some regions, while others experience increased rainfall and flooding events. The effects of these changes are profound. As water scarcity becomes more widespread, competition for limited resources intensifies, potentially leading to conflicts and social unrest. Given the importance of water resources and the undeniable impact of climate change on their availability and quality, it is imperative that we deepen our understanding of this complex relationship. This study aims to assess the socio-economic and environmental impacts of climate change on water resources. By doing so, it seeks to provide policymakers, scientists, and communities with information that will guide decision-making processes and direct effective climate change adaptation and mitigation strategies. In conclusion, the impact of climate change on water resources cannot be overstated. This study aims to contribute to our understanding of this critical issue by highlighting the urgency of addressing climate change and its consequences on water resources and sustainability. This study examines the effects of changing precipitation patterns and increasing temperatures due to climate change on underground and surface water resources in Turkey. By conducting this research, we hope to pave the way for informed decision-making and encourage collective responsibility to protect our water resources for future generations.

Climate Change and Its Impacts on Saker (Falco cherrug) and Peregrine (Falco peregrinus) Falcons: How the Changes Will Affect Their Migration, Diet, Offspring, and Conservation Efforts

Climate change is considered as a real danger to many birds including raptors such as the Saker falcons (Falco cherrug) and Peregrine falcons (Falco peregrinus). This article answers the question of how climate change shifts the migration, feeding, and breeding habits of these raptors. These migratory birds keep facing disturbances in their yearly cycle due to recent changes in temperature, precipitation patterns, and pollution. This results in changes in the migration points, as they travel for longer or shorter distances, especially to make their nestlings, and changes in their prey availability, affecting their migration pattern. Also, air pollution affected them significantly, where mercury (Hg) and lead (Pb) levels in their feathers were significantly high. Fortunately, it has not affected their general health yet. As for their reproduction success, it was interrupted, making it necessary to take conservation initiatives and tactics to save these species amid climate-induced alterations by analyzing ecological interconnections and evolutionary mechanisms. The findings highlight the necessity of mitigating climate change effects on migrating raptors to guarantee their survival rate is high and satisfy ecological system equilibrium.

Patterns of surface water dynamics and storage changes in a basin of Bundelkhand Region, India: Implications for water management

AbstractSurface water is essential for agricultural, domestic and industrial production worldwide. Monitoring surface dynamics is crucial for sustainable ecosystems and global water resources. Importance of monitoring surface water dynamics is even more pronounced in the semi‐arid regions worldwide. An analysis of surface water extent and volume change patterns has been conducted, comparing these dynamics with alterations in precipitation patterns within a basin in Central Bundelkhand, a semi‐arid region in the Central India prone to droughts. To map the waterbodies, we leveraged Sentinel‐1 SAR data using an automated mapping framework and utilised DEM dataset to extract bathymetry using interpolation with modifications using water persistence. Analysis revealed a lag in surface water peak water level with respect to accumulated rainfall by 2–3 months. Furthermore, we have categorised the water bodies into small, medium and large by surface area and found that smaller water bodies show a higher intra‐annual variance, while medium and large water bodies show a lower intra‐annual variance. The findings suggest that smaller communities reliant on smaller water bodies are at a higher risk from climate variability in the region and a delay in attaining peak surface storage across the basin causes further challenges to water management.

Performance Evaluation of Satellite Precipitation Products During Extreme Events—The Case of the Medicane Daniel in Thessaly, Greece

Mediterranean tropical-like cyclones, or Medicanes, present unique challenges for precipitation estimations due to their rapid development and localized impacts. This study evaluates the performance of satellite precipitation products in capturing the precipitation associated with Medicane Daniel that struck Greece in early September 2023. Utilizing a combination of ground-based observations, reanalysis, and satellite-derived precipitation data, we assess the accuracy and spatial distribution of the satellite precipitation products GPM IMERG, GSMaP, and CMOPRH during the cyclone event, which formed in the Eastern Mediterranean from 4 to 7 September 2023, hitting with unprecedented, enormous amounts of rainfall, especially in the region of Thessaly in central Greece. The results indicate that, while satellite precipitation products demonstrate overall skill in capturing the broad-scale precipitation patterns associated with Medicane Daniel, discrepancies exist in estimating localized intense rainfall rates, particularly in convective cells within the cyclone’s core. Indeed, most of the satellite precipitation products studied in this work showed a misplacement of the highest amounts of associated rainfall, a significant underestimation of the event, and large unbiased root mean square error in the areas of heavy precipitation. The total precipitation field from IMERG Late Run and CMORPH showed the smallest bias (but significant) and good temporal correlation against rain gauges and ERA5-Land reanalysis data as a reference, while IMERG Final Run and GSMaP showed the largest underestimation and overestimation, respectively. Further investigation is needed to improve the representation of extreme precipitation events associated with tropical-like cyclones in satellite precipitation products.

The Impact of Climate Change on Flowering Patterns and Productivity in Floriculture: A Comprehensive Review

The floriculture industry, a vital component of global horticulture, is increasingly threatened by climate change, which disrupts flowering patterns, reduces productivity, and alters the market value of ornamental crops. This review synthesizes current research on how climatic factors-such as temperature fluctuations, altered precipitation, elevated atmospheric CO₂, and extreme weather events-affect key aspects of floricultural crop growth and phenology. Rising temperatures accelerate flowering in many species but can also lead to heat stress, floral bud abortion, and reduced flower quality in sensitive crops like roses (Rosa hybrida) and snapdragons (Antirrhinum majus). Similarly, changes in precipitation patterns, including drought and waterlogging, further complicate floral development by impairing water and nutrient uptake. Elevated CO₂ generally promotes biomass accumulation and water-use efficiency but may not necessarily translate into improved floral yield or quality. To address these challenges, the adoption of adaptive strategies such as breeding climate-resilient varieties, implementing optimized agronomic practices, and utilizing controlled environment agriculture is critical. Future research must focus on species-specific and long-term studies to identify the differential impacts of climate change on diverse floricultural species. Moreover, multi-stressor impact assessments and exploration of phenotypic plasticity and genetic adaptation are needed to develop cultivars capable of maintaining high performance under complex environmental conditions. Integrating climate models and decision support systems will further enable precise forecasting and strategic planning, supporting growers in mitigating climate-related risks. By advancing understanding in these areas, the floriculture industry can better adapt to changing climates and maintain economic sustainability, ensuring the continued success of this important sector amidst global environmental shifts.

Analyzing the impact of climatic conditions on rainfed wheat yield in northwest Iran: a parametric and nonparametric approach

ABSTRACT It is essential to comprehend the relationship between agricultural yields and climatic conditions, especially concerning food security and the possible threats to crop output. Wheat is a crucial agricultural crop that covers a significant amount of rainfed production regions in Iran. This study utilized parametric and nonparametric approaches to assess rainfed wheat yield. The study centered on the Tabriz area in northwest Iran, examining precipitation patterns concerning rainfed wheat cultivation. The study focused on analyzing seasonal and distinct rainfall patterns during the cultivation period, utilizing widely recognized drought metrics such as the standardized precipitation index and the standardized precipitation–evaporation index. The study findings indicate a notable upward trend in rainfed wheat output over the analyzed period. The Mann–Kendall test resulted in a p-value of 0.031, indicating statistical significance for the observed rising trend. We conducted trend removal and normalized rainfed wheat yield figures based on seasonal precipitation to study the data more thoroughly. The second phase of the growing season was particularly notable, spanning from the completion of germination to the beginning of blooming. Instead of analyzing precipitation for the full growing season, concentrating on autumn precipitation or the time from germination to blooming might improve yield forecasts and determinations.

A protocol for model intercomparison of impacts of marine cloud brightening climate intervention

Abstract. A modeling protocol (defined by a series of climate model simulations with specified model output) is introduced. Studies using these simulations are designed to improve the understanding of climate impacts using a strategy for climate intervention (CI) known as marine cloud brightening (MCB) in specific regions; therefore, the protocol is called MCB-REG (where REG stands for region). The model simulations are not intended to assess consequences of a realistic MCB deployment intended to achieve specific climate targets but instead to expose responses to interventions in six regions with pervasive cloud systems that are often considered candidates for such a deployment. A calibration step involving simulations with fixed sea surface temperatures (SSTs) is first used to identify a common forcing, and then coupled simulations with forcing in individual regions and combinations of regions are used to examine climate impacts. Synthetic estimates constructed by superposing responses from simulations with forcing in individual regions are considered a means of approximating the climate impacts produced when MCB interventions are introduced in multiple regions. A few results comparing simulations from three modern climate models (CESM2, E3SMv2, and UKESM1) are used to illustrate the similarities and differences between model behavior and the utility of estimates of MCB climate responses that were synthesized by summing responses introduced in individual regions. Cloud responses to aerosol injections differ substantially between models (CESM2 clouds appear much more susceptible to aerosol emissions than the other models), but patterns in precipitation and surface temperature responses were similar when forcing is imposed with similar amplitudes in the same regions. A previously identified La Niña-like response to forcing introduced in the Southeast Pacific is evident in this study, but the amplitude of the response was shown to markedly differ across the three models. Other common response patterns were also found and are discussed. Forcing in the Southeast Atlantic consistently (across all three models) produces weaker global cooling than that in other regions, and the Southeast Pacific and South Pacific show the strongest cooling. This indicates that the efficiency of a given intervention depends on not only the susceptibility of the clouds to aerosol perturbations, but also the strength of the underlying radiative feedbacks and ocean responses operating within each region. These responses were generally robust across models, but more studies and an examination of responses with ensembles would be beneficial.

Impact of Climate Change on the Bioclimatological Conditions Evolution of Peninsular and Balearic Spain During the 1953–2022 Period

Climate change is altering the temperature and precipitation patterns in the Iberian Peninsula and on the Balearic Islands, with potential impacts on the distribution of plant communities. This study analyses the evolution of bioclimatic units in this region during the 1953–2022 period. Data from 3668 weather stations distributed throughout the study area were analysed. Two 35-year periods (1953–1987 and 1988–2022) were compared to assess changes in macrobioclimates and bioclimates. The results showed expansion of the Mediterranean macrobioclimate, whose total area increased by 6.93%, mainly at the expense of the Temperate macrobioclimate. For bioclimates, a trend towards more xeric and continental conditions was observed in the Mediterranean region, while temperate areas moved towards homogenisation of climate conditions. Likewise, two new bioclimates were detected, which indicate the emergence of new climate conditions. These results suggest a reorganisation of bioclimatic conditions, with particular implications for biodiversity in mountainous and transitional areas, where endemic species face higher risks of habitat loss. This study provides useful information for developing targeted conservation strategies, establishing a baseline for monitoring future changes and developing early warning systems for vulnerable ecosystems, thus supporting the design of climate-adapted conservation measures in the region studied.

Correcting Multivariate Biases in Regional Climate Model Boundaries: How Are Synoptic Systems Impacted Over the Australian Region?

AbstractSynoptic climatology, which connects atmospheric circulation with regional environmental conditions, is pivotal to understanding climate dynamics. While regional climate models (RCMs) can reproduce key mesoscale precipitation patterns, biases related to synoptic circulation from the driving model, typically global climate models (GCMs), often remain unaddressed. This study examines the influence of correcting systematic bias in RCM boundaries on the representation of Australian synoptic systems. We utilize a structural self‐organizing map to evaluate the frequency, persistence, and transitions of daily synoptic systems. Our findings reveal that an RCM with multivariate bias‐corrected boundaries improves the representation of synoptic systems compared to the driving GCM, or an RCM with uncorrected or simply bias‐corrected boundaries, particularly in reference to the frequency of systems identified. This demonstrates that appropriately correcting RCM boundary conditions helps correct many of the circulation errors inherited from the driving GCM but not all.