The long‐term memory of the ocean makes sea surface temperature anomalies (SSTAs) become a significant predictor for the subsequent atmosphere, and the tropical ocean is primarily regarded as a major ...source of atmospheric anomalies. While in North Pacific, the local midlatitude SSTAs also have large contributions but have not been adequately considered yet. We discover a strong connection between the Kuroshio‐Oyashio Extension (KOE) SSTAs in spring and the local atmospheric circulation anomalies in following summer at interannual timescale, wherein, the spring KOE SSTAs are generally independent of tropical ocean, and they are primarily induced by the concurrent atmospheric anomalies via surface heat flux and ocean dynamic processes. The spring KOE SSTAs can persist to summer, and then generate nearly reversed whole‐layer atmospheric circulation anomalies in their north side through both diabatic heating and atmospheric transient eddy forcing. Consequently, precipitation anomalies in Pan‐Pacific regions are distinctly modulated from spring to summer.
Plain Language Summary
Because of the vast heat‐holding capacity and the long‐term memory of ocean, sea surface temperature anomalies (SSTAs) are usually taken as the significant factors to understand and predict climate anomalies. On interannual timescale, attentions have primarily centered on the tropical SSTAs, but recent studies indicated that the SSTAs in mid‐to‐high latitudes, especially in the Kuroshio‐Oyashio Extension (KOE) could have important feedbacks on the atmosphere. In this study, the KOE SSTAs in spring are discovered to have large interannual variability, and they are independent of the tropical SSTAs but closely linked to the subsequent summer atmospheric anomalies. It is found that the spring KOE SSTAs are mainly forced by the atmosphere via the surface heat flux and the ocean dynamic processes. In turn, they can persist to summer, and then play a dominant role in the air‐sea interaction in North Pacific, inducing remarkable geopotential height anomalies in north side. Consequently, in terms of the KOE SSTAs evolving from spring to summer, the Pan‐Pacific precipitation anomalies are distinctly modulated due to the opposite air‐sea interaction processes in the two seasons. These findings advocate for the use of springtime KOE SSTAs as a predictive indicator for following summer atmospheric and precipitation conditions.
Key Points
The spring Kuroshio‐Oyashio Extension (KOE) sea surface temperature anomalies (SSTAs) are independent of tropical ocean and primarily forced by the concurrent local atmosphere at interannual timescale
The spring KOE SSTAs can persist to summer and exert a delayed cross‐season impact on the subsequent summer atmosphere
Associated with the spring KOE SSTAs, precipitation anomalies in Pan‐Pacific regions are distinctly modulated from spring to summer
The significantly increasing incidence of type 2 diabetes mellitus (T2DM) over the last few decades triggers the demands of T2DM animal models to explore the pathogenesis, prevention, and therapy of ...the disease. The altered lipid metabolism may play an important role in the pathogenesis and progression of T2DM. However, the characterization of molecular lipid species in fasting serum related to T2DM cynomolgus monkeys is still underrecognized.
Untargeted and targeted LC-mass spectrometry (MS)/MS-based lipidomics approaches were applied to characterize and compare the fasting serum lipidomic profiles of T2DM cynomolgus monkeys and the healthy controls.
Multivariate analysis revealed that 196 and 64 lipid molecules differentially expressed in serum samples using untargeted and targeted lipidomics as the comparison between the disease group and healthy group, respectively. Furthermore, the comparative analysis of differential serum lipid metabolites obtained by untargeted and targeted lipidomics approaches, four common serum lipid species (phosphatidylcholine 18:0_22:4, lysophosphatidylcholine 14:0, phosphatidylethanolamine PE 16:1_18:2, and PE 18:0_22:4) were identified as potential biomarkers and all of which were found to be downregulated. By analyzing the metabolic pathway, glycerophospholipid metabolism was associated with the pathogenesis of T2DM cynomolgus monkeys.
The study found that four downregulated serum lipid species could serve as novel potential biomarkers of T2DM cynomolgus monkeys. Glycerophospholipid metabolism was filtered out as the potential therapeutic target pathway of T2DM progression. Our results showed that the identified biomarkers may offer a novel tool for tracking disease progression and response to therapeutic interventions.
Multimorbidity has become an important health challenge in the aging population. Accumulated evidence has shown that multimorbidity has complex association patterns, but the further mechanisms ...underlying the association patterns are largely unknown.
Summary statistics of 14 conditions/diseases were available from the genome-wide association study (GWAS). Linkage disequilibrium score regression analysis (LDSC) was applied to estimate the genetic correlations. Pleiotropic SNPs between two genetically correlated traits were detected using pleiotropic analysis under the composite null hypothesis (PLACO). PLACO-identified SNPs were mapped to genes by Functional Mapping and Annotation of Genome-Wide Association Studies (FUMA), and gene set enrichment analysis and tissue differential expression were performed for the pleiotropic genes. Two-sample Mendelian randomization analyses assessed the bidirectional causality between conditions/diseases.
LDSC analyses revealed the genetic correlations for 20 pairs based on different two-disease combinations of 14 conditions/diseases, and genetic correlations for 10 pairs were significant after Bonferroni adjustment (P<0.05/91 = 5.49E-04). Significant pleiotropic SNPs were detected for 11 pairs of correlated conditions/diseases. The corresponding pleiotropic genes were differentially expressed in the brain, nerves, heart, and blood vessels and enriched in gluconeogenesis and drug metabolism, biotransformation, and neurons. Comprehensive causal analyses showed strong causality between hypertension, stroke, and high cholesterol, which drive the development of multiple diseases.
This study highlighted the complex mechanisms underlying the association patterns that include the shared genetic components and causal effects among the 14 conditions/diseases. These findings have important implications for guiding the early diagnosis, management, and treatment of comorbidities.
The El Nino-Southern Oscillation (ENSO)-associated wintertime atmospheric teleconnection patterns in two Pacific decadal oscillation (PDO) phases are investigated using ERA-20C reanalysis data for ...1950–2010. A strengthened ENSO-associated Pacific-North American (PNA) teleconnection pattern presents in PDO positive phase, while a West Pacific (WP) pattern over Northwestern Pacific and a squeezed PNA pattern coexist when ENSO occurs in PDO negative phase. The dynamical role of atmospheric transient eddy feedbacks to the teleconnection patterns are highlighted in the present study. When ENSO occurs in PDO positive phase, the uniform strengthened westerly jet anomalies downstream of the climatological main body of jet accompany with energetic transient eddy anomalies over Northeastern Pacific. The transient eddy feedbacks largely enhance and favor the strengthened PNA pattern. When ENSO occurs in PDO negative phase, the strengthened westerly jet anomalies appear to separate into two parts, one locating north of the climatological main body of jet and the other at the downstream. The accompanied transient eddy anomalies also split into two parts. Under such conditions, the transient eddy feedbacks are limited over Northeastern Pacific and favor a weak PNA pattern. However, the transient eddy anomalies over Northwestern Pacific strengthen, and the feedbacks also strengthen and largely contribute to the WP pattern. Moreover, the transient eddy anomalies over Northwestern Pacific seem to be anchored along the anomalously poleward strengthened oceanic subarctic frontal zone (SAFZ) in PDO negative phase. The enhanced atmospheric baroclinicity anomalies, coupled with the strengthened SAFZ, energize atmospheric transient eddy anomalies, and work as the potential maintenance in shaping the WP pattern.
A lagged Maximum Covariance Analysis is used to examine the impact of North Pacific storm‐track activity on midlatitude oceanic frontal intensity in this study. It is found that an enhanced storm ...track tends to intensify the oceanic frontal intensity with a lag of 1–2 months. The forcing effect of storm‐track anomalies on oceanic frontal intensity is strongest in autumn, followed by that in summer and winter, and it is weakest in spring. Moreover, the mixed layer heat budget analysis suggests that sea surface temperature anomalies (SSTAs) related to oceanic fronts are primarily attributed to the storm‐track‐induced net surface heat flux and Ekman advection anomalies, while contributions of geostrophic advection and entrainment are relatively small. In summer and autumn, the impact of net surface heat flux anomalies on SSTAs plays a more important role than that of Ekman heat transport anomalies. Whereas in winter, Ekman heat transport anomaly forcing is comparable to the net surface heat flux forcing. Anomalous turbulent heat fluxes contribute to generating net surface heat flux anomalies in those three seasons, while the shortwave radiative fluxes make a strong contribution in summer but have little impact in winter. The anomalies of both net surface heat flux and Ekman heat transport are presumed to be associated with storm‐track‐induced surface wind anomalies. Results of the present study provide observational evidences for the positive feedback between the North Pacific storm‐track activity and midlatitude oceanic frontal intensity.
Key Points
The intensified storm track tends to enhance oceanic front with a lag of 1–2 months
The most significant impact of the storm track on the oceanic front appears in autumn
The storm track exerts its influence on the oceanic front by means of net surface heat flux and Ekman advection
Pavement transverse cracks are associated with pavement performance. However, due to low recognition accuracy, the transverse cracking detection through vehicle's vibration response has hardly been ...considered. This paper proposes a novel method for pavement transverse cracking detection using reconstructed vehicle vibration signal. An accelerometer installed in the vehicle collects the vibration response between the vehicle and the pavement transverse cracks. A brand-new approach to data processing is suggested that transforms a one-dimensional vibration signal into a two-dimensional vibration image. The two-dimensional vibration image generated can obtain different features effectively from the time domain. Based on Gray Level Concurrence Matrix (GLCM) algorithm, a characteristic index established from the vibration image's contrast can distinguish transverse cracks from uncracked sections. Then its feasibility was investigated by 410 pavement sections, the accuracy of the index is 93.84%. The transverse crack detection method proposed in this paper seems promising for precisely identifying pavement transverse cracks.
Understanding the persistence of the Southern Annular Mode (SAM) is important for the intraseasonal and decadal predictability of SAM. Using the ERA‐40 and ERA‐Interim reanalysis data, this study ...introduces a new method to quantify the relative roles of barotropic and baroclinic eddy feedbacks in the SAM persistence. Through a hybrid Eulerian‐Lagrangian Finite Amplitude Wave Activity diagnostic, it is found that (i) transient wave activity is important in driving the SAM, but it provides a negative feedback to the SAM persistence. (ii) Irreversible potential vorticity mixing, through barotropic processes in the upper troposphere, plays an important role in driving and sustaining the SAM variability. Particularly, following the poleward shift of the eddy‐driven jet, the reduction/enhancement in effective diffusivity on the jet's poleward/equatorward flank can be understood by a stronger/weaker zonal jet acting as a robust/leaky mixing barrier. (iii) Baroclinic eddy generation and vertical wave propagation mainly act to sustain the SAM variability.
Key PointsA new method quantifying baroclinic/barotropic eddy feedback in SAM introducedBarotropic processes drive and sustain SAM; baroclinic ones extend SAM persistenceWave activity drives SAM variability but feedbacks negatively for SAM persistence
Recently, metal nanoclusters (MNCs) emerged as a new class of luminescent materials and have attracted tremendous interest in the area of luminescence-related applications due to their excellent ...luminous properties (good photostability, large Stokes shift) and inherent good biocompatibility. However, the origin of photoluminescence (PL) of MNCs is still not fully understood, which has limited their practical application. In this mini-review, focusing on the origin of the photoemission emission of MNCs, we simply review the evolution of luminescent mechanism models of MNCs, from the pure metal-centered quantum confinement mechanics to ligand-centered p band intermediate state (PBIS) model via a transitional ligand-to-metal charge transfer (LMCT or LMMCT) mechanism as a compromise model.
Observations and climate models have shown that the midlatitude eddy-driven jet can exhibit an evident latitudinal shift in response to lower-tropospheric thermal forcing (e.g., the tropical SST ...warming during El Nino or extratropical SST anomalies associated with the atmosphere-ocean-sea ice coupling). In addition to the direct thermal wind response, the eddy feedbacks-including baroclinic mechanisms, such as lower-level baroclinic eddy generation, and barotropic mechanisms, such as upper-level wave propagation and breaking-can all contribute to the atmospheric circulation response to lower-level thermal forcing, but their individual roles have not been well explained. In this study, using a nonlinear beta -plane multilevel quasigeostrophic channel model, the mechanisms through which the lower-level thermal forcing induces the jet shift are investigated. By diagnosing the finite-amplitude wave activity budget, the baroclinic and barotropic eddy feedbacks to the lower-level thermal forcing are delineated. Particularly, by examining the transient circulation response after thermal forcing is switched on, it is shown that the lower-level thermal forcing affects the eddy-driven jet rapidly by modifying the upper-level zonal thermal wind distribution and the associated meridional wave propagation and breaking. The anomalous baroclinic eddy generation, however, acts to enhance the latitudinal shift of the eddy-driven jet only in the later stage of transient response. Furthermore, the barotropic mechanism is explicated by overriding experiments in which the barotropic flow in the vorticity advection is prescribed. Unlike the conventional baroclinic view, the barotropic eddy feedback, particularly the irreversible PV mixing through barotropic vorticity advection and deformation, plays a major role in the atmospheric circulation response to the lower-level thermal forcing.
Although the summers of 2021 and 2022 are both in the two successive La Niña decaying stages and under the same climate background of negative Pacific Decadal Oscillation (PDO) phase and global ...warming trend, they exhibit significantly different and even opposite precipitation patterns in the Yangtze River Valley (YRV) as well as in the Indian monsoon region (IMR). In contrast to the abundant precipitation and lower temperature in the YRV in summer 2021, in summer 2022 the YRV experiences severe drought and extremely high temperatures, which is also accompanied by Mega‐floods in the IMR. This study identifies the joint influence of sea surface temperature anomalies (SSTAs) in Niño4 and Barents Sea (BS) regions as the underlying cause for the contrast YRV precipitation anomalies in the summers of 2021 and 2022. Specifically, the cold SSTAs in both Niño4 and BS regions in summer 2021 favor stronger and southward shifted western North Pacific subtropical high (WNPSH), leading to more precipitation in the YRV, which is however generally reversed but more intense in summer 2022 because of the synergistic effect of cold Niño4 and warm BS SSTAs. Moreover, the induced extreme precipitation in the IMR in summer 2022, which is absent in summer 2021 due to the offsetting effect of cold SSTAs in both Niño4 and BS regions, in turn further strengthens the anomalous atmospheric circulations via its released large diabatic heating and serves as a relay pathway for the dramatic drought and heat wave in the YRV.
Plain Language Summary
The El Niño‐Southern Oscillation (ENSO) is known to be the most significant interannual signal and one of the major factors for summer precipitation anomaly in East Asia. Nevertheless, the two summers of 2021 and 2022 are characterized by almost opposite precipitation patterns in the Yangtze River Valley (YRV) even though they are both in the two successive La Niña decaying stages. Our study demonstrates that except for the cold sea surface temperature anomalies (SSTAs) with obvious differences in both intensity and position in Niño4 region, the opposite SSTAs in Barents Sea region may play a dominant role in determining the strong contrast precipitation patterns in the YRV as well as in the Indian monsoon region (IMR). As the result of the synergistic effect of cold Niño4 and warm BS, the extreme IMR precipitation also serves as a relay pathway for the dramatic drought and heat wave in the YRV in summer 2022. It suggests that to clearly understand and accurately predict the climate anomalies in East Asia should consider the mid‐high latitude signals besides the tropical ENSO signal, especially in the context of global warming when the signals and influences from the mid‐high latitudes are becoming more and more prominent.
Key Points
The two La Niña decaying summers in 2021 and 2022 see nearly opposite precipitation patterns in Yangtze River valley
Synergistic effect of cold Niño4 region and warm Barents Sea is the essential cause for the extreme summer drought in Yangtze River valley
Indian monsoon precipitation plays a relaying role in linking the SST forcing and the Yangtze River valley precipitation via teleconnection
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