Could the North Pacific Oscillation be modified by the initiation of the East Asian winter monsoon?

Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 33(6), (2020): 2389-2406, doi:10.1175/JCLI-D-19-0112.1.This study investigates the modulation of North Pacific Oscillation (NPO) variability upon initiation of the East Asian winter monsoon (EAWM). The data show that the initiation of EAWM in the Philippine Sea strongly connects to the southern lobe variability of the NPO in January followed by a basin-scale oceanic Victoria mode pattern. No apparent connection was found for the northern lobe of the NPO when the ENSO signals are removed. The strengthening of the EAWM in November interacts with the Kuroshio front and generates a low-level heating source in the Philippine Sea. Significant Rossby wave sources are then formed in the lower to midtroposphere. Wave ray tracing analyses confirm the atmospheric teleconnection established by the Rossby wave propagation in the mid- to upper troposphere. Analyses of the origin of wave trajectories from the Philippine Sea show a clear eastward propagating pathway that affects the southern lobe of the NPO from the southern lobe of the western Pacific pattern at 500 hPa and above on the time scale of 20 days. No ray trajectories from the lower troposphere can propagate eastward to influence the central-eastern subtropical Pacific. The wave propagation process is further supported by the coupled model experiments.We thank three anonymous reviewers for their constructive comments that have helped to improve the clarity of the presentation. This study was supported by the MOST Grants 107-2611-M-002-013-MY4 and 108-2111-M-002-006 -MY3, Taiwan.2020-08-2

The application of localized surface plasmons resonance in Ag nanoparticles assisted Si chemical etching

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Ding, R., Dai, H., Li, M., Huang, J., Li, Y., Trevor, M., & Musselman, K. P. (2014). The application of localized surface plasmons resonance in Ag nanoparticles assisted Si chemical etching. Applied Physics Letters, 104(1), 011602 and may be found at https://doi.org/10.1063/1.4855615Localized surface plasmons excited by Ag nanoparticles are introduced in the chemical etching process of silicon. A special crateriform structure with gradually varying radius is achieved by the surface electromagnetic field enhancement effect of localized surface plasmons resonance (LSPR). Theoretical analysis demonstrates that the formation kinetics of the crateriform structures conforms to the local electromagnetic field enhancement and forward scattering induced by LSPR. The LSPR assisted photocatalytic etching offers a potential approach for the preparation of the surface microstructures used in optoelectronic devices.National Natural Science Foundation of China [91333122, 51372082, 51172069, 50972032, 61204064, 51202067]Ph.D. Programs Foundation of Ministry of Education of China [20130036110012, 20110036110006]Fundamental Research Funds for the Central Universities [11ZG02

The NTD Nanoscope: potential applications and implementations

<p>Abstract</p> <p>Background</p> <p>Nanopore transduction detection (NTD) offers prospects for a number of highly sensitive and discriminative applications, including: (i) single nucleotide polymorphism (SNP) detection; (ii) targeted DNA re-sequencing; (iii) protein isoform assaying; and (iv) biosensing via antibody or aptamer coupled molecules. Nanopore event transduction involves single-molecule biophysics, engineered information flows, and nanopore cheminformatics. The NTD Nanoscope has seen limited use in the scientific community, however, due to lack of information about potential applications, and lack of availability for the device itself. Meta Logos Inc. is developing both pre-packaged device platforms and component-level (unassembled) kit platforms (the latter described here). In both cases a lipid bi-layer workstation is first established, then augmentations and operational protocols are provided to have a nanopore transduction detector. In this paper we provide an overview of the NTD Nanoscope applications and implementations. The NTD Nanoscope Kit, in particular, is a component-level reproduction of the standard NTD device used in previous research papers.</p> <p>Results</p> <p>The NTD Nanoscope method is shown to functionalize a single nanopore with a channel current modulator that is designed to transduce events, such as binding to a specific target. To expedite set-up in new lab settings, the calibration and troubleshooting for the NTD Nanoscope kit components and signal processing software, the NTD Nanoscope Kit, is designed to include a set of test buffers and control molecules based on experiments described in previous NTD papers (the model systems briefly described in what follows). The description of the Server-interfacing for advanced signal processing support is also briefly mentioned.</p> <p>Conclusions</p> <p>SNP assaying, SNP discovery, DNA sequencing and RNA-seq methods are typically limited by the accuracy of the error rate of the enzymes involved, such as methods involving the polymerase chain reaction (PCR) enzyme. The NTD Nanoscope offers a means to obtain higher accuracy as it is a single-molecule method that does not inherently involve use of enzymes, using a functionalized nanopore instead.</p

Nonlinear local lyapunov vectors and their applications to ensemble predictions

Nonlinear local Lyapunov vectors (NLLVs), theoretically inherited from the linear Lyapunov vectors (LVs) in a nonlinear framework, are developed to indicate orthogonal directions in phase space with different perturbation growth rates. Practically NLLVs generates flow dependent perturbations with full nonlinear models as in the breeding method, but regularly conducts the Gram–Schmidt reorthonormalization processes on the perturbations. The advantages of the sampling of the unstable subspace with the mutually orthogonal NLLVs instead of the most unstable direction with the dependent bred vectors (BVs) are clarified by using their respective unstable mode to predict the structure of forecast error growth. Additionally, the NLLVs have overall higher but correlated local dimensions compared to the BVs which may be beneficial for the former to increase the ensemble spread and capture the instabilities as well. The NLLV method is used to generate initial perturbations and implement ensemble forecasts in nonlinear models (the Lorenz63 model, Lorenz96 model, a barotropic quasi-geostrophic model and the Zebiak-Cane model) to explore the validity of the NLLV method. The performance of the NLLV method is compared comprehensively and systematically with other methods such as the ensemble transform Kalman filter (ETKF) method, the BV and the random perturbation (Monte Carlo) methods. Overall, the ensemble spread of NLLVs is more consistent with the errors of the ensemble mean, which indicates the better performance of NLLVs in simulating the evolution of analysis errors. In addition, the NLLVs perform significantly better than the BVs in terms of reliability and the random perturbations in resolution. The NLLV scheme has slightly higher ensemble forecast skill than the ETKF scheme. The NLLV scheme has significantly simpler algorithm and less computation time than the ETKF.Non UBCUnreviewedAuthor affiliation: Institute of Atmospheric Physics, Chinese Academy of SciencesFacult

Interannual impact of the Victoria mode on the winter-spring surface air temperature over Eurasia and North America

Abstract Variations of the Victoria mode (VM) have received considerable attention due to their profound impacts on the climate systems in the pan-North Pacific. However, works about its impact on surface air temperature (SAT) variability over Eurasia and North America, which may be responsible for extreme weather and climate events, are limited. Here we show a significant positive and negative relationship between the VM and the winter-spring SAT anomalies over mid-to-high-latitude east-central Eurasia (MEE) and eastern North America (ENA), respectively. A local energy budget analysis shows that the contribution of the surface heat fluxes associated with the VM to the SAT anomalies is confined mainly to MEE and may not explain the formation of SAT anomalies over ENA. Furthermore, VM-induced anomalous atmospheric circulations play a crucial role in the formation of notable SAT anomalies. The positive (negative) VM is linked to negative (positive) precipitation and upper-tropospheric wind convergence (divergence) anomalies over the western North Pacific, which contribute to positive (negative) Rossby wave source (RWS) anomalies near the East Asian westerly jet core. These RWS anomalies act as disturbances that propagate eastward, exciting a wave train-like pattern. The high-level positive and negative geopotential height anomalies of the Rossby wave dominate MEE and ENA, respectively, leading to the variation in SAT anomalies. These results could advance our understanding of the relationship between the VM and SAT over the Northern Hemisphere and inspire us to pay more attention to the VM climate impacts

Re-Examination of the Decadal Change in the Relationship between the East Asian Summer Monsoon and Indian Ocean SST

This study examines the decadal change in the relationship between two major Indian Ocean (IO) sea surface temperature patterns, namely the Indian Ocean dipole (IOD) and northern IO and the East Asia summer monsoon (EASM) in the early 2000s. In 1991-1999, the former epoch, the interannual variability of EASM was associated with the IOD-like pattern in the original paper and its relationship weakened in 2000-2016. There are two possible causes for this decadal change; stronger land-sea thermal contrast as a local forcing in latter epoch, which may result in the weakening of the relationship between the IO and the EASM. In addition, the influence of El Niño-southern Oscillation (ENSO) on the western North Pacific subtropical high (WNPSH) could be changed depending on the frequency of ENSO. In the 2000s, the intensity of the low frequency (LF)-type ENSO (42-86 months period) events was weaker compared to the former epoch but that of quasi-biennial (QB)-type ENSO (16-36 months period) remained persistent. This could explain that the QB-type ENSO is remote forcing that modulates the change in the relationship between the tropical IO patterns and EASM in the 2000s. © 2018 by the authors