Response of Coastal Upwelling East of Hainan Island in the South China Sea to Sudden Impact and Long-Term Variability of Atmospheric Forcing

The wind-driven coastal upwelling east of Hainan Island (UEH) in the northwestern South China Sea (SCS) is sensitive to the multi-scale variability of atmospheric forcing. This chapter focuses on two ends of time scales of atmospheric forcing: very short-time or sudden impact, i.e., typhoon passages; and long-term variability associated with El Niño events. The response of the sea surface temperature (SST) associated with the UEH to typhoon passages was investigated based on concurrent satellite SST and wind products. The long-term variability and response of the UEH to super El Niño events were analyzed based on recent 30 years of satellite data. The results show that the UEH has significant responses to atmospheric forcing. Meanwhile, the ocean circulation also plays an important role in modulation of the coastal upwelling

Algorithm of Abnormal Audio Recognition Based on Improved MFCC

AbstractCharacteristics extraction has a great effect on the audio training and recognition in the audio recognition system. MFCC algorithm is a typical characteristics extraction method with stable performance and high recognition rate. For the situation that MFCC has a large amount of computation, an improved algorithm MFCC_E is introduced. The computation of MFCC_E is reduced by 50% compared with the standard algorithm MFCC, and it make the hardware implementation is easy. The experimental result indicated that MFCC_E and MFCC have the same recognition rate roughly, yet the computational complexity of MFCC_E is much smaller

A seasonal circulation index for the ocean and its application to the South China Sea

Ocean circulation is crucial in redistributing mass and energy on Earth. However, it varies significantly on a seasonal time scale due to external forcing. To quantify the seasonality of ocean circulation, we propose a seasonal circulation index (SCI). This index is defined as the normalized maximum deviation from the velocity vector, whose magnitude is the largest in one period. We have substantiated the efficiency of this index using the monsoon wind in the South China Sea (SCS). By utilizing this index, we have obtained the 3D structure of the seasonality of ocean circulation in the SCS. The SCI and the seasonal circulation amplitude (SCA) exhibit large values over 0.9 and 0.8 m s-1 in the western boundary current. Alternating southwest-northeastward bands of SCI with high and low values are distributed from the north shelf to the south, especially in the eastern basin. Although SCA decreases significantly with depth, SCI exhibits values higher than 0.7 in both the middle and deep layers, indicating a noteworthy seasonality and middle-layer enhancement in the abyssal basin of the SCS

Tropical storm-induced turbulent mixing and chlorophyll-a enhancement in the continental shelf southeast of Hainan Island

AbstractBased on moored observations and remote sensing data in July and August 2005, energy sources for enhancing turbulent mixing and possible mechanisms of phytoplankton bloom in the continental shelf southeast of Hainan Island under the influence of Washi, a fast-moving and weak tropical storm, are analyzed in this paper. Observations show that strong near-inertial internal waves were generated by the rapidly changing wind stress and the near-inertial energy was dissipated quickly across the thermocline. The strong turbulent mixing associated with the near-inertial baroclinic shear instability occurred with maximum eddy diffusivity above 3.2×10−4m2s−1, and the surface chlorophyll-a (Chl-a) concentration after the storm increased by 22.2%. The Chl-a concentration augment was inferred to be an upper ocean biophysical response to the enhanced near-inertial turbulent mixing which could increase the upward nutrient flux into the surface low eutrophic zone during the passage of Washi

Determination of chromosomal ploidy in Agave ssp.

Chromosome observation is necessary to elucidate the structure, function and organization of Agave plants’ genes and genomes. However, few researches about chromosome observation of Agave ssp. were done, not only because their chromosome numbers are large, but also because their ploidies are complicated. The root tips of 19 Agave ssp. germplasms were used as materials for determining their chromosomal ploidies. Through normal pre-treatment, fixation, digesting and Giemsa staining, the glass slides with expelled cells on them were obtained. Observed with a light microscope, the results showed that 10 germplasms are diploids, including 4 wild species and a local variety which are good parents for cross-breeding. The main cultivar in China A.hybrid cv NO 11648 is also a diploid. A. cantala Roxb used as parent for disease-resistant breeding is a triploid. A. hybrid cv nanya NO.1 and A. hybrid cv nanya NO.2 are tetraploids. The other germplasms belong to polyploids. Although three germplasms’ ploidies were reported before, the other 16 germplasms’ were first reported in this paper. These results will provide theoretical basis for cross-breeding

Impulsive rotational Raman scattering of N2 by a remote "air laser" in femtosecond laser filament

We report on experimental realization of impulsive rotational Raman scattering from neutral nitrogen molecules in a femtosecond laser filament using an intense self-induced white-light seeding "air laser" generated during the filamentation of an 800 nm Ti: Sapphire laser in nitrogen gas. The impulsive rotational Raman fingerprint signals are observed with a maximum conversion efficiency of ~0.8%. Our observation provides a promising way of remote identification and location of chemical species in atmosphere by rotational Raman scattering of molecules.Comment: 4 pages, 4 figure

Global Stability of Positive Periodic Solutions and Almost Periodic Solutions for a Discrete Competitive System

A discrete two-species competitive model is investigated. By using some preliminary lemmas and constructing a Lyapunov function, the existence and uniformly asymptotic stability of positive almost periodic solutions of the system are derived. In addition, an example and numerical simulations are presented to illustrate and substantiate the results of this paper