Precipitation Structure Research Articles

Spatial Aligned Mean: A Method to Improve Consensus Forecasts of Precipitation from Convection-Allowing Model Ensembles

Abstract Ensembles of convection-allowing model (CAM) forecasts are increasingly being used in operational numerical weather forecasting. Several approaches have been devised to find consensus among ensemble forecast fields, including the arithmetic ensemble mean and, more recently, the patchwise localized probability-matched (LPM) mean. However, differences in spatial distribution and intensity of precipitation features among ensemble members make it difficult to construct an ensemble mean product that characterizes the consensus while preserving precipitation structures forecasted by the individual ensemble members. To overcome this problem, this study aims to develop and test a method for improving ensemble consensus precipitation forecasts by directly considering the spatial offsets among ensemble members. This study uses a multiscale spatial alignment technique to align the precipitation features of each ensemble member to a common location, and the spatial aligned mean (SAM) is obtained by averaging the realigned members. It is shown that implementing SAM and subsequently applying the LPM technique to the average of all aligned members (SAM–LPM) can significantly improve the warm season precipitation forecast scores using common metrics such as equitable threat score (ETS). Also, improvement in the structure of features of heavy rainfall is shown from summer 2023 flash-flooding cases. Thus, SAM and SAM–LPM can be excellent candidate methods for calculating an ensemble consensus and providing ensemble consensus guidance to forecasters. Significance Statement High-impact rainfall events, such as flash floods, result in many billion-dollar loss events in the United States each year. This study seeks to improve the prediction of such events when using guidance from convection-allowing model (CAM) ensemble forecasts, such as the U.S. operational High-Resolution Ensemble Forecast (HREF) and the nascent Rapid Refresh Forecast System (RRFS). The proposed method, the spatial aligned mean (SAM), directly addresses the common issue of disparity in the predicted location of convective systems among ensemble members that confounds traditional ensemble consensus methods. In this study, it is found that SAM improves ensemble consensus guidance for high-impact rainfall events in both the HREF and the Center for Analysis and Prediction of Storms (CAPS) Finite-Volume Cubed-Sphere (FV3)-limited area model (LAM) CAM ensemble forecast system, a proxy for the future RRFS.

Thermal Cycling Behavior of Aged FeNiCoAlTiNb Cold-Rolled Shape Memory Alloys

Fe–Ni–Co–Al-based systems have attracted a lot of interest due to their large recoverable strain. In this study, the microstructure and thermal cycling behaviors of Fe41Ni28Co17Al11.5Ti1.25Nb1.25 (at.%) 98.5% cold-rolled alloys after annealing treatment at 1277 °C for 1 h, followed by aging for 48 h at 600 °C, were investigated. From the electron backscatter diffraction results, we see that the texture intensity increased from 9.4 to 16.5 mud and the average grain size increased from 300 to 400 μm as the annealing time increased from 0.5 h to 1 h. The hardness results for different aging heat treatment conditions show the maximum value was reached for samples aged at 600 °C for 48 h (peak aging condition). The orientation distribution functions (ODFs) displayed by Goss, brass, and copper were the main textural features in the FeNiCoAlTiNb cold-rolled alloy. After annealing, strong Goss and brass textures were formed. The transmission electron microscopy (TEM) results show that the precipitate size was ~10 nm. The X-ray diffraction (XRD) results show a strong peak in the (111) and (200) planes of the austenite (⁠⁠γ, FCC) structure for the annealed sample. After aging, a new peak in the (111) plane of the precipitate (⁠⁠γ′, L12) structure emerged, and the peak intensity of austenite (⁠⁠γ, FCC) decreased. The magnetization–temperature curves of the aged sample show that both the magnetization and transformation temperature increased with the increasing magnetic fields. The shape memory properties show a fully recoverable strain of up to 2% at 400 MPa stress produced in the three-point bending test. However, the experimental recoverable strain values were lower than the theoretical values, possibly due to the fact that the volume fraction of the low-angle grain boundary (LABs) was small compared to the reported values (60%), and it was insufficient to suppress the beta phases. The beta phases made the grain boundaries brittle and deteriorated the ductility. On the fracture surface of samples after the three-point bending test, the fracture spread along the grain boundary, and the cross-section microstructural results show that the faces of the grain boundary were smooth, indicating that the grain boundary was brittle with an intergranular fracture.

The precipitate structure of copper-based antibacterial and antiviral agents enhances their longevity for kitchen use

The transmission of bacteria through cooking surfaces, the handles of hot plates, and cookware that is not cleaned frequently can pose a problem. In this study, a copper ion-based mixed solution (CBMS) containing only inorganic ions with controlled acidity was assessed as a new antibacterial and antiviral agent. We analysed the structure of the precipitates, and various deposits measuring a few micrometres were observed on the substrates. We have defined these deposits as strongly bonded scaly copper dispersion (SBSCD) structures.The antibacterial copper component of the liquid agent changed over time after application; this mechanism appears to be responsible for the maintenance of antibacterial performance.CBMS demonstrates high safety for the human body and can be applied to stainless steel materials used in kitchens and tables. It exhibits a sustained antibacterial effect over time, and its antibacterial properties can be continuously maintained.

Reshaping precipitate structure and morphology in an Al-Zn-Mg-Cu alloy through dislocation-precipitate interactions

Mechanical properties of age-hardenable alloys are significantly influenced by the intricate interplay between precipitates and mobile dislocations. This study examined how dislocations interact with nanosized precipitates at the atomic scale in an under-aged Al-Zn-Mg-Cu alloy. Results revealed that precipitates hinder dislocation movement but are also sheared by them during deformation. Furthermore, the sheared precipitates experienced structural collapse and deviated from their usual evolutionary path, forming ordered but non-periodic topologically close-packed structures and altered morphologies. The discoveries provide insights into dislocation-precipitate interactions and strain-induced structural changes, which could inspire strategies to modulate precipitates with tailored microstructures and thereby improved alloy properties.

Microphysical characteristics of torrential predecessor rain events over the Yangtze River Delta Area and the related tropical cyclones

The precipitation structures and microphysical characteristics of predecessor rain events (PREs) over the Yangtze River Delta area and related tropical cyclones (TCs) from 2014 to 2019 were investigated using Dual-frequency Precipitation radar data from Global Precipitation Measurement (GPM) for drop size distributions (DSDs). Results showed that the total mean rain rate of PREs was larger than that of TCs, primarily due to higher convective and stratiform rain rates, with enhanced fractional coverage of convective rain in PREs. Examination of microphysical characteristics revealed that a greater quantity of small-sized droplets and a smaller quantity of medium- as well as large-sized droplets contributed towards PREs in comparison with TCs. The conclusion still holds when partitioning DSDs based on different precipitation rate categories. Further investigation of DSDs using gamma functions illustrated that precipitation in PREs had lower average mass-weighted diameters (Dm) and enhanced normalized number concentration (Nw) compared with TCs; partitioning precipitation into convective and stratiform components illustrated a larger Dm and lower Nw in TCs than PREs. The analysis of microphysical and thermodynamical processes using the reanalysis data indicates that relatively intense convective activity with drier conditions may be favorable to enhancing raindrop growth through collision-coalescence processes, as a result of larger Dm in TCs than PREs. The empirical relations (Z–R algorithms) applied in different rain regimes (stratiform, convective, and total PREs) revealed significant diversities, relying on weather conditions and geographical locations. Plain language summaryThe Yangtze River Delta area is an important economic belt in China. Under climate change, observed frequent occurrences of weather extremes of heavy rainfall and tropical cyclones (TCs) exert adverse effects on economic development in this region. Thus, a deep understanding of the mechanism of TCs torrential rainfall in the Yangtze River Delta area is urgently necessary. In this study, we investigated the precipitation patterns and microphysical characteristics of predecessor rain events (PREs) in the Yangtze River Delta region, and their association with TCs in the South China Sea-Western North Pacific Ocean (SCS-WNPO) area from 2014 to 2019. We found that PREs had a higher total mean precipitation rate than TCs. Further examination using gamma functions demonstrated that PREs exhibited lower average mass-weighted diameters (Dm) and higher normalized intercept parameters (Nw) than TCs. This pattern persisted when distinguishing between convective and stratiform precipitation components. We believe that our study makes a significant contribution to the literature because these results provide valuable insights into the distinct precipitation characteristics of PREs and TCs in the study region and contribute to a better understanding of tropical cyclone-related rainfall patterns, and act as a scientific basis for disaster mitigation.

Simultaneous removal of nitrate, copper, carbamazepine, and calcium from micropolluted water by fulvic acid through promotion of denitrification and microbial-induced calcium precipitation: Performance and mechanism

In this paper, a study of the denitrification strain Cupriavidus sp. W12 was conducted to remove copper (Cu2+), carbamazepine (CBZ), and calcium (Ca2+) by microbial-induced calcium precipitation (MICP) after adding fulvic acid (FA). After the addition of 20 mg/L FA, the removal efficiencies of nitrate (NO3–-N), Cu2+, CBZ, and Ca2+ reached 100.0 %, 98.7 %, 96.6 %, and 73.6 %, correspondingly and there was no accumulation of nitrite (NO2–-N). FA stimulated the growth of strain W12, improved electron transfer activity, and facilitated the conversion of gaseous nitrogen. The research revealed that FA might enhance microbial activity and result in a more dense and porous structure of the biological precipitate. Cu2+ and CBZ were removed by co-precipitation and adsorption. As the initial report of FA promoting MICP to remove complex pollutants, this paper offers a theoretical foundation for NO3–-N, Cu2+, CBZ, and Ca2+ remediation in micropolluted water.

The renewed tin-weighting treatment as sustainable and durable flame-retardant approach for protein silk fabric

The facile development of a sustainable and durable flame-retardant approach for protein silk is of interest. Inspired by silk tin-weighting technology, this study developed a novel and sustainable in-situ deposition strategy based on biomass phytic acid to impart durable flame-retardant performance to silk fabrics. The chemical structure of insoluble chelating precipitation, and the surface morphology, thermal stability, combustion behavior, flame-retardant capacity, laundering resistance, and flame-retardant mode of action of the tin-weighting silk samples, were explored. The Sn-, P-, Si-containing insoluble chelating precipitation formed within the fiber interior and combined with silk fibers through electrostatic attraction and metal salt chelation. As a result, the tin-weighting silk displayed excellent self-extinguishing capacity, with the damaged length reduced to 9.2 cm and the LOI increased to 31.6 %; it also achieved self-extinguishing after 30 washing cycles, demonstrating high flame-retardant efficacy and laundering resistance. Moreover, the tin-weighting silk also showed the obvious suppression in smoke and heat generation by 55.6 % and 35.7 %, respectively. The synergistic charring action of phosphate groups, tin metal salts, and silicates was beneficial for enhancing the fire safety of silk. The tin-weighting treatment also displayed a minor impact on mechanical performance of silk fabrics.

Precipitate Structure, Microstructure Evolution Modeling and Characterization in an Aluminum Alloy 7050 Friction Stir Weld

Precipitate Structure, Microstructure Evolution Modeling and Characterization in an Aluminum Alloy 7050 Friction Stir Weld

Application of the AI2 Climate Emulator to E3SMv2's Global Atmosphere Model, With a Focus on Precipitation Fidelity

AbstractCan the current successes of global machine learning‐based weather simulators be generalized beyond 2‐week forecasts to stable and accurate multiyear runs? The recently developed AI2 Climate Emulator (ACE) suggests this is feasible, based upon 10‐year simulations with a network trained on output from a physics‐based global atmosphere model using a grid spacing of approximately 110 km and forced by a repeating annual cycle of sea‐surface temperature. Here we show that ACE, without modification, can be trained to emulate another major atmospheric model, EAMv2, run at a comparable grid spacing for at least 10 years with similarly small climate biases—a prerequisite to wider applicability. With an analysis that combines multiple temporal, spatial, and frequency domain perspectives, we show that ACE faithfully represents the spatiotemporal structure of EAMv2 precipitation and related variables. Finally, we show that a pretrained ACE network is able to adapt to a new global climate model simulation data set with 10 fewer training steps than when starting from random initialization, all while still maintaining low levels of climate bias. Further analysis of these fine‐tuning experiments reveal ACE's intriguing ability to interpolate between distinct global climate models.

Complex interplay of sulfate aerosols and meteorology conditions on precipitation and latent heat vertical structure

An eight-year satellite observation dataset reveals that sulfate aerosols significantly influence the vertical structure of precipitation and latent heat (LH) in the Beijing-Tianjin-Hebei (BTH) region during summer. In this period, prevalent sulfate aerosols combine with warm, humid southerly winds and elevated convective available potential energy (CAPE), influencing precipitation dynamics. Under polluted conditions with specific CAPE and precipitation top temperature (PTT) ranges, precipitation particles experience accelerated growth within the mixed-phase layer, delineated by the −5 °C to 2 °C isotherms, compared to pristine environments. This results in a marked increase in both the intensity and height at which the maximum LH is released. Subsequent analysis reveals that hygroscopic sulfate aerosols, acting as cloud condensation nuclei (CCN), amplify the collision-coalescence process within the mixed layer amid high cloud water content, propelling rapid precipitation particle growth and elevating the PTT. This warming effect surpasses the cooling contribution from robust CAPE, culminating in a net elevation of PTT under polluted scenarios compared to pristine ones. Additionally, quantification of PTT sensitivity to both CAPE and aerosol optical depth (AOD) unveils a high consistency between satellite-detected PTT responses to CAPE and those predicted by cloud-resolving model simulations. The study deduces that the role of aerosols as CCN in either invigorating or diminishing the collision-coalescence process is contingent on the available cloud water.

Detectable anthropogenic influence on the changes in structure of precipitation over China using CMIP6 models

In the context of global warming, both droughts and extreme precipitation events occur frequently over China. Precipitation, being a major driving factor and a crucial component of the water cycle, is highly sensitive to the human activities. This study uses high-resolution gridded daily precipitation, categorizing precipitation into 20 equal intervals, to analyze the changes in precipitation structure across the region. The investigation reveals a significant transition from light to heavy precipitation in China from 1961 to 2014, characterized by a notable decrease in light precipitation and a substantial increase in heavy precipitation. Employing the latest generation of CMIP6 models, it is found that the models can accurately replicate this change, with GHG forcing exacerbating this trend, particularly noticeable, whereas results under AER forcing are contrary to observational outcomes. Simultaneously, the study notes that CMIP6 models exhibit limitations in simulating the spatial distribution of trends in light precipitation but perform well in reproducing the trend pattern for heavy precipitation. Attribution results suggest that the observed shift from light to heavy precipitation is predominantly a result of the combined influence of GHG and AER forcing. However, significant regional variations exist in this transition. In the future, this transition is expected to persist, with heavy precipitation showing a more pronounced increasing trend.

Diurnal Variation in Summer Precipitation and the Characteristics of Precipitation Events in the Western Tarim Basin, China

The Tarim Basin in the western part of Northwest China (NWC) is the largest inland basin in the world and one of the most arid regions in the middle latitudes. In recent years, heavy precipitation events have occurred frequently in this region, especially in the western Tarim Basin (WTB), due to the climate change. Based on the hourly precipitation data from 2010 to 2022, the diurnal variation in summer precipitation and the characteristics of precipitation events with different durations in WTB have been analyzed. The results mainly show that (1) the diurnal variations in the precipitation amount (PA), precipitation frequency (PF) and precipitation intensity (PI) mainly present a unimodal pattern, but the times of maximum value do not coincide. The peak value of PA and PF appears between 01:00 and 03:00 BJT (Beijing Time), while the valley value appears around 18:00 BJT, yet the peak value of PI appears between 20:00 and 23:00 BJT with no obvious valley value. (2) There are some differences in the diurnal variation characteristics of precipitation among different summer months and different regions. (3) During the past decade, the precipitation structure in WTB has been continuously adjusted, and short-duration- and long-duration-precipitation-dominant periods appear alternately. On the whole, short-duration precipitation has been more frequent in summer, accounting for 70% of the total precipitation events and 40% of the total accumulated precipitation amount. These results can help us to better understand the refined physical characteristics of precipitation events and enhance our understanding of the local climate in the WTB under the background of climate change.

Eliminating metallurgical defects and achieving strength-ductility combination in selective laser melted martensitic stainless steel through high-pressure annealing

Due to high difficulty in fabricating and processing high-strength metals, additive manufacturing has been considered to have broad prospects compared to the traditional casting means. However, unavoidable metallurgical defects and strength–ductility trade-off dilemma have become Achilles' heels for their practical applications. In this work, one high-pressure annealing (HPA) strategy was introduced to process the selective laser melted (SLM) martensitic stainless steel. The microstructures and mechanical properties of as-built, high temperature annealing and HPA and as-rolled SLM samples were systematically investigated. It was found that the HPA treatment makes the stainless steel achieve the significant yield strength of 1828 MPa and the comparable plastic strain of 36.2% compared to other samples. The pores and laminar structures from the SLM process were eliminated by HPA. What is more, the HPA treatment results in uniform carbide precipitation, grain refinement and nanoscale heterogeneous structure comprising a series of coarse and fine grains. The physical mechanism for nanoscale heterogeneous structure induced by HPA was discussed from the perspective of the cooperative effect of temperature and pressure. Additionally, the strengthening contributions from grain refinement, carbide precipitation, dislocation hardening, heterogeneous structure and pore closure were quantitatively determined. The current study not only reveals the comprehensive effect of temperature and pressure on microstructure and mechanical properties, but also establishes HPA as an effective method to evade the strength-ductility trade-off in alloys fabricated by additive manufacturing.

Correlated 4D-STEM and EDS for the classification of fine Beta-precipitates in aluminum alloy AA 6063-T6

Tuning the properties of aluminum alloys AA 6063-T6 involves artificial aging to induce precipitate formation, particularly β’’ and β’ phases. Previous characterization challenges due to their similar appearance are addressed here by correlating 4D scanning transmission electron microscopy (4DSTEM) and energy-dispersive spectroscopy (EDS) mapping. This approach allows us to analyze the structure and composition of precipitates individually, overcoming limitations of conventional imaging and structural analysis techniques when the precipitates appear simultaneously, as is often the case. We present detailed characterizations of needle-shaped Beta precipitates, revealing distinct diffraction patterns (DPs) and compositional differences. The method's applicability extends beyond aluminum alloys, offering a promising strategy for complex composite material characterization with multimodal scanning transmission electron microscopy (STEM) techniques.

Changes in precipitation phases based on the multi-discrimination method in the Tibetan Plateau

Global warming is rapidly changing the precipitation structure, and the shift in precipitation phases is even more pronounced in the Tibetan Plateau (TP), a region sensitive to global climate change. The accuracy of precipitation phase discrimination is essential for studying precipitation variability. Based on the observed data from 112 meteorological stations in the study area obtained from the China Meteorological Administration (CMA) and the National Climatic Data Center (NCDC) before 1980, we compared and assessed six methods for distinguishing precipitation phases and the optimal method was determined to complete the precipitation phase data after 1980 in the study area. Subsequently, the changes in precipitation amount, intensity, and frequency were analyzed by classifying them into light, moderate, heavy, and extreme precipitation using the percentile threshold discrimination method. It found that the dynamic threshold temperature method (presented by Ding et al., 2014) was the most effective to distinguish precipitation phases in the TP, and its performance was further improved from 80.9% to 86.1% after using frequency intersection and probability guarantee methods. Precipitation was mainly concentrated in July. Meanwhile, the proportion of snowfall to total precipitation (S/P) was approximately 9%. From 1961 to 2020, the amount of total precipitation, rainfall and snowfall in the TP exhibited increasing trends, while the sleet demonstrated a persistent decline. Spatial and temporal heterogeneity existed in the changes of precipitation of different phases. The average single precipitation amount increased. Moreover, the changes in the amount and frequency of extreme precipitation were more pronounced. Increased frequency and amount of both rainfall and snowfall were distributed in the central and eastern parts of the study area with a more significant proportion. In contrast, the peripheral areas witnessed a decrease. The spatial distribution of frequency and amount of different precipitation intensities was comparable to that of the total precipitation. This study offers novel procedure into changes of precipitation phases at high altitudes, which will inform future research on climate change and water resource management.

Characteristics of rainfall distribution induced by tropical cyclones using GSMaP data over the Vietnam region

ABSTRACT Tropical cyclones (TCs) contribute significantly to rainfall along Vietnam's coast, yet their complex precipitation structures remain poorly resolved, hindering forecast skill. This study analyzes TC rainfall distributions over the Vietnam East Sea from 2000 to 2020. The Global Satellite Mapping of Precipitation (GSMaP) product provides precipitation estimates with 0.1° resolution at hourly intervals, enabling detailed structural characterization. Rainfall features are analyzed across TC intensities, motion vectors, landfall locations, and interactions with cold surge (CS) air masses. Results show that total coverage differences are less significant than the intensity variations in narrow inner core rainbands. Asymmetric rainfall distributions concentrate in the front-right quadrant but shift after landfall. Northern Vietnam observes higher TC frequencies, but southern regions experience heavier extreme rains. Additionally, CS intrusions substantially intensify eyewall convection and redirect TC precipitation. These structural sensitivities visible in GSMaP observations elucidate the dynamics modulating TC rainfall. Characterizing multi-scale interactions and precipitation processes aids in forecasting and impact assessment for these high-risk storms with complex regional behavior.

The detailed moisture transport structure in extreme precipitation on the Tibetan Plateau caused by storm over the Bay of Bengal

AbstractThe storms over the Bay of Bengal (BoB) often combine with the weather systems such as the South Branch Trough (SBT) and the West Pacific Subtropical High (WPSH) to transport plenty of moisture inducing extreme precipitation on the Tibetan Plateau (TP). Determining the fine moisture structures of storms helps understand mechanism of this kind of extreme precipitation. An extreme precipitation occurred on the TP influenced by storm Rashmi (2008). A Lagrangian approach is scrutinized the forward and backward moisture transport trajectories of Rashmi and the TP, respectively. The moisture source of this extreme precipitation is relatively clear, which comes from the collaborative influence of Rashmi with the southwest jet generated by the SBT and the WPSH. Utilizing a three‐dimensional K‐means clustering method devised in this study, the Rashmi's forward trajectories are classified into three categories, the particles ascending with the northward movement of Rashmi (45%), consistently below 1 km (37.5%), and rapidly ascending into the southwest jet stream (17.5%). Notably, 97.5%, 1.2%, and 91% of these categories impact the TP, respectively. The moisture transport structure of storm is verified by backward tracking of moisture over the TP. In addition, the three‐dimensional moisture trajectories classification method is recommended when trajectories suffer rapid altitude changes.

Unveiling the Mechanism in Nickel Loss During the Neutralization of Pregnant Acid Leach Solution by Various Alkaline Chemicals Using Electron Imaging, X-Ray Diffraction, and Electron Energy Loss Spectroscopy Analyses

ABSTRACT Removal of iron and aluminum from nickel-bearing pregnant leach solution is imperative prior to recovering nickel. However, the mechanisms into the loss of both nickel and cobalt in precipitate products during the neutralization process remained unclear and debatable. In this study, the precipitation ratios of nickel, as well as other valuable metals in iron precipitate products, were investigated by examining bulk and surface properties of iron precipitates using X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and electron energy loss spectroscopy. Amorphous ferrihydrite was identified as the major phase for iron precipitates. Over 99% precipitation ratio for iron and aluminum was achieved at pH 3. The loss of nickel in iron precipitates was strongly dependent on solution pHs, and the losses of nickel were found to be 3%, 8%, and 28% at pHs of 3, 4, and 5, respectively. The type of alkaline chemicals impacted the mineralogical composition of iron precipitate products and loss of valuable metals but had a minor impact on iron precipitation ratio. This work revealed three major mechanisms for the loss of nickel and cobalt during iron precipitation process: (1) entrainment of nickel-bearing PLS in filtered products, (2) surface adsorption on iron precipitates, and (3) lattice incorporation of nickel in iron precipitates. Additionally, the result of desorption experiments by H+ and Na+ ions showed that approximately 55–85% of lost nickel was incorporated within the lattice structure of iron precipitates, while the degree of nickel incorporation depends on the type of neutralizing reagents, precipitation conditions, and washing media.

An excellent combination of strength and ductility via hierarchical precipitation structures in Co-free medium-entropy alloys

A Co-free non-equiatomic Ni2·5CrFeAl0·25Ti0.25 medium-entropy alloy (MEA) with an excellent strength-ductility synergy was fabricated, which shows a multiphase structure composed of face-centered cubic (FCC), L12 (ordered FCC), and Cr-rich body-centered cubic (BCC) phase by thermomechanical processing. Specifically, the aged sample displays the outstanding yield tensile strength (YTS, ∼1188 MPa), ultimate tensile strength (UTS, ∼1560 MPa) and work-hardening rate (WHR, ∼4.5 GPa) values as well as an acceptable plasticity of ∼16.6%. Theoretical calculations suggest that precipitation strengthening significantly contributes to achieving the fascinating tensile strength among various strengthening contributors. Further analyses reveal that multiple nanoscale stacking-fault (SF) networks are activated during plastic deformation in the aged alloy. Accordingly, the dual effects consisting of the hierarchical precipitation structure and SF networks lead to the combination of excellent tensile strength and strain-hardening capacity.

Land-sea contrast of vertical structure of precipitation over Sumatra revealed by GPM DPR observations

This study examines the land-sea contrast in the vertical structure of precipitation over Sumatra and its surrounding ocean using eight years (2014–2021) of dual-frequency precipitation radar (DPR) data from the Global Precipitation Measurement (GPM) mission. The study area is segmented into Ocean, Coast I (west coast), Land I (west of Barisan Mountains), Land II (east of Barisan Mountains), and Coast II (east coast). The effective reflectivity factor (Ze), rainfall rate (R), and two raindrop size distribution (DSD) parameters, namely the mass-weighted mean diameter (Dm) and the normalized intercept (Nw), were analyzed. Stratiform and deep convective rainfall were the most frequent types in Coast I, followed by Ocean, Land I, Land II, and Coast II. In contrast, shallow convective rainfall was the most common type in Ocean, followed by Coast I, Land I, Land II, and Coast II. The average rain top height (RTH) was found to be higher in Land II and Coast II than in Ocean, Coast I, and Land I, in accordance with the surface rainfall intensity pattern previously reported by other studies. Furthermore, the data on heavy ice precipitation demonstrated an increase from the ocean to the coast and land, with a significant number of instances observed in Land I, Land II, and Coast II, in addition to Coast I. This contrast in heavy ice precipitation and RTH influences DSD. The land-sea contrast of DSD is more pronounced for deep convective rains. Deep convective exhibited a lower frequency of large raindrops over the ocean than over the coast and land, as reflected in the Dm profile. Conversely, raindrop concentration, particularly small drops, was higher at sea. The percentage of Dm > 2 mm at sea was approximately 2%, rising to 4–6% in Land II and Coast II. The land-sea contrast in the vertical structure of precipitation over Sumatra exhibited apparent diurnal variation. Larger Dm and smaller Nw were observed over Land I and Coast I, particularly in the afternoon and evening, correlating with peak rainfall. This pattern aligns with heavy ice precipitation profiles, vertical relative humidity (RH), and wind profiles. This study highlights the complexities and potential discrepancies between vertical precipitation profiles and surface precipitation data, underscoring the nuanced nature of land-sea precipitation migration.