Nanjing University of Information Science and Technology

About: Nanjing University of Information Science and Technology is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Precipitation & Aerosol. The organization has 14129 authors who have published 17985 publications receiving 267578 citations. The organization is also known as: Nan Xin Da.

Relative Roles of Dynamic and Thermodynamic Processes in Causing Evolution Asymmetry between El Niño and La Niña

Abstract: Observed SST anomaly (SSTA) in the equatorial eastern Pacific exhibits an asymmetric evolution characteristic between El Nino and La Nina. While El Nino is characterized by a rapid decay after its peak and a fast phase transition to a cold episode in the following winter, La Nina is characterized by a weaker decay after its peak and a reintensification of cold SSTA in the second year. The relative roles of dynamic (wind field) and thermodynamic (heat flux) processes in causing the asymmetric evolutions are investigated through a mixed layer heat budget analysis. The result shows both dynamic and thermodynamic processes contribute to the evolution asymmetry. The former is related to asymmetric wind responses in the western Pacific, whereas the latter is associated with asymmetric cloud–radiation–SST and evaporation–SST feedbacks. A strong negative SSTA tendency occurs during El Nino decaying phase, compared to a much weaker positive SSTA tendency during La Nina decaying phase. Such a difference lea...

An Enhanced Rectenna Using Differentially-Fed Rectifier for Wireless Power Transmission

Abstract: This letter presents an enhanced rectenna with a differentially-driven rectifier for wireless power transmission applications. By utilizing differential feeding, a patch antenna with increased gain is proposed. To be directly connected with the differentially-fed patch antenna as a rectenna, a differentially-driven rectifier is designed so that the use of balun can be omitted. The rectenna shows a maximum efficiency of 73.9% under the input power density of ${\hbox {207}}~\mu\hbox{W/cm}^{2}$ . Furthermore, compared with a reference rectenna of the same aperture size, the proposed rectenna performs higher efficiency and yields larger output DC power, which is more than 1.5 times as high as that of the reference rectenna.

Recent strengthening of the stratospheric Arctic vortex response to warming in the central North Pacific

Abstract: The stratospheric Arctic vortex (SAV) plays a critical role in forecasting cold winters in northern mid-latitudes. Its influence on the tropospheric mid- and high-latitudes has attracted growing attention in recent years. However, the trend in the SAV during the recent two decades is still unknown. Here, using three reanalysis datasets, we found that the SAV intensity during 1998–2016 has a strengthening trend, in contrast to the weakening trend before that period. Approximately 25% of this strengthening is contributed by the warming of sea-surface temperature (SST) over the central North Pacific (CNP). Observational analysis and model experiments show that the warmed CNP SST tends to weaken the Aleutian low, subsequently weakening the upward propagation of wavenumber-1 planetary wave flux, further strengthening the SAV. This strengthened SAV suggests important implications in understanding the Arctic warming amplification and in predicting the surface temperature changes over the northern continents. The stratospheric Arctic vortex plays a critical role in forecasting cold winters in northern mid-latitudes. Here the authors show that the stratospheric Arctic vortex strengthened during 1998–2016, with ~25% of this strengthening contributed by warming in the central North Pacific.