A number of past studies have attempted to place modern Atlantic TC activity in a longer-term context using regional proxy evidence of past landfalling Atlantic hurricane activity [6][7][8] . Some studies 4 have sought to infer past changes in activity from plausible local conditioning factors such as wind strength and Sea Surface Temperature (SST), though the interpretations of these studies have been contested 5 . Qualitative comparisons between paleo-hurricane reconstructions appear to show some temporal coherence 8-9 .However, no past studies have attempted to synthesize multiple records from distinct regions into a basin-integrated reconstruction of Atlantic hurricane activity. Moreover, no past studies have sought to quantitatively relate estimated variations in hurricane or TC activity to reconstructions of the key large-scale climate factors known to have a 3 significant influence on modern Atlantic TC activity. Here we produce an empirical record of past landfalling Atlantic hurricane activity by combining information from multiple sedimentary records of TC-induced overwash. Further we compare these resulting estimates to independent statistical model predictions of past TC activity driven by proxy-based large-scale climate reconstructions.Sediment-based overwash reconstructions of TC landfall are limited in number, but span a wide geographic area across the North Atlantic basin impacted by hurricanes. Our compilation includes (Figure 1) a site from the Caribbean (Vieques, PR 6,9,10 ), one from the U.S. Gulf Coast 11 , one from the southeastern U.S. coast 8 , three from the mid-Atlantic coast (one from New York 9 and two from New Jersey 12,13 ) and two from southeastern New England (one from Rhode Island 14 and another from Massachusetts 15 ) yielding 5 distinct regional series. We obtained a probabilistic estimate of past basin-wide landfalling hurricane activity using an appropriately weighted combination of the information from these 5 regional series, and incorporating radiocarbon age model uncertainties.An independent estimate of past tropical cyclone activity was obtained using a statistical model for Atlantic TC counts. This previously developed and validated 16,3 statistical model conditions annual Atlantic TC counts on three key large-scale climate state variables tied to historical variations in Atlantic TC counts: (i) Sea Surface Temperature (SST) over the main development region (MDR) for tropical Atlantic TCs, which reflects favorability of the local thermodynamic environment, (ii) the El Niño/Southern Oscillation (ENSO) which influences the amount of (unfavorable) vertical wind shear, and (iii) the North Atlantic Oscillation (NAO) phenomena which affects the tracking of storms (which influences how favorable an environment they 4 encounter). The statistical model was driven by proxy-based reconstructions 17,18 of these three state variables (Figure 2), yielding a predicted history of Atlantic TC counts for past centuries We compared the sediment-based record against the above statistical e...
It has been a goal to create artificial evaporators that have highly efficient solar steam generation (SSG) performance under omnidirectional illumination to solve the global drinking water crisis. Although some evaporators with high evaporation rates and efficiencies have been reported, their inefficient performance under oblique illumination conditions remain to be overcome. Pinecones, with their delicate transpiration channels, photo‐thermal moisture‐sensitive deployable structure, and 3D Fibonacci helically‐arranged scales, inspire the design of this efficient evaporator under omnidirectional illumination. Herein, ultra‐black pinecone (UBP) with multi‐branched, arterially porous, and hierarchical structures shows excellent SSG performance under omnidirectional illumination. UBP achieves a high evaporation rate and efficiency of 1.86 kg m−2 h−1 and 97.85% respectively, under one sun illumination. The SSG performance under oblique incidence conditions of UBP are not degraded but improved (2.194 g h−1 under incident angle of 90°) because the UBP can recover reflection and radiation energy losses, avoid cosine energy losses, and absorb heat from the warm environment. The UBP also exhibits high evaporation rate in real weather and good durability and salt resistance in concentrated brine, which ensures its great potential applications in wastewater treatment and solar desalination.
Bi2Te3-based compounds are important near room temperature thermoelectric materials with commercial applications in thermoelectric modules. However, new routes leading to improved thermoelectric performance are highly desirable. Incorporation of superparamagnetic nanoparticles was recently proposed as a means to promote the thermoelectric properties of materials, but its feasibility has rarely been examined in mainstream thermoelectric materials. In this study, high quality single-crystalline Bi2Te2.7Se0.3 nanoplates and Ni nanoparticles were successfully synthesized by solvothermal and thermal decomposition methods, respectively. Bulk nanocomposites consisting of Bi2Te2.7Se0.3 nanoplates and superparamagnetic Ni nanoparticles were prepared by spark plasma sintering. It was found that incorporation of Ni nanoparticles simultaneously increased the carrier concentration and provided additional scattering centers, which resulted in enlarged electric conductivities and Seebeck coefficients. The greatly improved ZT was achieved due to the increase in power factor. Spark plasma sintered bulk nanocomposites of Bi2Te2.7Se0.3 nanoplates incorporated by 0.4 mol %Ni nanoparticles (in molar ratio) showed a figure-of-merit ZT of 0.66 at 425 K, equivalent to 43% increase when compared to pure Bi2Te2.7Se0.3 nanoplates. The results revealed that incorporation of magnetic nanoparticles could be an effective approach for promoting the thermoelectric performance of conventional semiconductors.
We apply the multitaper frequency domain–singular value decomposition signal detection method to the investigation of coherent patterns of variation in seasonal Northern Hemisphere sea level pressure and conterminous U.S. summer drought during the period 1895–1995. The analysis identifies statistically significant patterns of spatiotemporal variability on interannual and bidecadal timescales indicative of both cold‐season and warm‐season atmospheric influences on North American drought patterns. The most robust signal found appears to be associated with the influences of the El Niño–Southern Oscillation (ENSO) on North American summer drought. Evidence is also found to support the existence of a roughly bidecadal drought signal tied to warm‐season atmospheric circulation changes. The “Dust Bowl” conditions of the 1930s appear to result from a combination of these bidecadal influences on drought conditions that coincide with a decrease in the amplitude of interannual ENSO‐related variability during the 1930s.
The role of the walnut (Juglans regia L.) shell in nut development, transportation, cleaning, and storage is often ignored. The shell suture seal and thickness are directly associated with kernel characteristics. In the present study, shell differentiation and microstructure were observed with an optical microscope using paraffin-sectioning and cryosectioning. The results showed that the parenchymal cells of the endocarp began to differentiate into sclerenchymal cells from 49 d after flowering (DAF), and the entire process continued until fruit maturation. The mature shell consists of three parts, including the sclereid layer (L1), sclerenchymal cell layer (L2), and shrunken cell layer (L3), from the outside to the inside. The shell thickness, suture seal grade, and mechanical strength were evaluated, as well as the lignin, cellulose, and phenolic compounds of the shell. Suture seal grade was positively correlated with lignin content, shell thickness, and L1 thickness and negatively correlated with shell cell diameter. Similarly, the mechanical strength of the shell was positively correlated with lignin content and L1 thickness. 'Qingxing' fruits were subjected to two treatments, namely, 30% shading and 70% shading, from 10 d after anthesis to maturity, with no shading used as control. After harvesting in September, nutshell sections showed thinner shells, with decreased contents of lignin and polyphenols, obtained under shaded conditions, and two of the three parts of the shell changed dramatically. The thinning of L1 and thickening of L3 eventually led to a thinner shell. The aim of this study was to evaluate the relationship among the shell structure, cellular components, and physical properties and provide a theoretical basis for cultivar breeding, rational planting density, and regulation of shell development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.