Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userA High-Resolution, Wave and Current Resource Assessment of Japan: The Web GIS Dataset
133
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The University of Tokyo and JAMSTEC have conducted state-of-the-art wave and current resource assessments to assist with generator site identification and construction in Japan. These assessments are publicly-available and accessible via a web GIS service designed by WebBrain that utilizes TDS and GeoServer software with Leaflet libraries. The web GIS dataset contains statistical analyses of wave power, ocean and tidal current power, ocean temperature power, and other basic physical variables. The data (2D maps, time charts, depth profiles, etc.) is accessed through interactive browser sessions and downloadable files.
rate research
Read More
A high-resolution wave climate projection for the northwestern Atlantic Ocean has been conducted to help assess possible regional impacts due to global climate change. The spectral wave model NOAA WAVEWATCH III is utilized with three coupled (two-way) grids to resolve the northwestern Atlantic and coastal southern and eastern USA at approximately 21 km and 7 km respectively, and covers the periods 1979--2003 (historic) and 2075--2099 (future). Hourly wind field forcings are provided by a high-resolution AGCM (MRI-AGCM 3.2S; 21 km) and allow for better modeling of large storm events (important for extreme event statistics). Climatological (25-year) comparisons between future and historical periods indicate significant wave heights will decrease in the northwestern Atlantic Ocean (-5.7 %) and Gulf of Mexico (-4.7 %) but increase in the Caribbean Sea (2.4 %). Comparisons also indicate that large changes in mean wave direction will occur in the Gulf of Mexico (5.0{deg}), with the largest occurring west of the Florida peninsula (over 15{deg}).
The output from an eddy-resolved multi-layered circulation model is used to analyze the vertical structure of simulated deep-sea eddies in the Japan Basin of the Japan/East Sea constrained by bottom topography. We focus on Lagrangian analysis of anticyclonic eddies, generated in the model in a typical year approximately at the place of the mooring and the hydrographic sections, where such eddies have been regularly observed in different years (1993--1997, 1999--2001). Using a quasi-3D computation of the finite-time Lyapunov exponents and displacements for a large number of synthetic tracers in each depth layer, we demonstrate how the simulated feature evolves of the eddy, that does not reach the surface in summer, into a one reaching the surface in fall. This finding is confirmed by computing deformation of the model layers across the simulated eddy in zonal and meridional directions and in the corresponding temperature cross sections. Computed Lagrangian tracking maps allow to trace the origin and fate of water masses in different layers of the eddy. The results of simulation are compared with observed temperature zonal and meridional cross sections of a real anticyclonic eddy to be studied at that place during the oceanographic Conductivity, Temperature, and Depth (CTD) hydrochemical survey in summer 1999. Both the simulated and observed eddies are shown to have the similar eddy core and the relief of layer interfaces and isotherms.
Knowledge about the characteristics of the atmospheric boundary layer are vital for the redistribution of air and suspended contents that are particularly driven by turbulent motions. Despite many modelling studies, detailed observations are still demanded of the development of turbulent exchange under stable and unstable conditions. In this paper we present an attempt to observationally detail atmospheric internal waves, under stable conditions, and associated turbulent overturning, under quasi-stable and unstable conditions. Therefore, we mounted 198 high-resolution temperature T-sensors on a cable. The instrumented cable was attached along the 213 m tall mast of Cabauw, the Netherlands, during late-summer 2017. The mast has standard and special meteorological equipment at extendable booms every 20 m in height. A sonic turbulence anemometer is at 60 m above ground. The extra, originally underwater-, T-sensor cable was suspended down from the 206-m level, temporarily for about 3 months. While in water the sensors have a response time of tw=0.4 s and drift of 0.001 degC per month, in air the response time ta=3 s is relatively slow and the apparent drift of about 0.1 degC per month relatively large. Least performance is during daytime. These T-sensor characteristics hamper quantitative atmospheric turbulence research, as it results in a relatively narrow inertial subrange of only one order of magnitude. Nevertheless, height-time images from two contrasting days show common nocturnal marginally stable density stratification supporting internal waves up to the buoyancy period of about 300 s, shear and convective deformation of the stratification over the entire 197 m range of observations.
The Gamma-Ray Observation of Winter Thunderclouds (GROWTH) collaboration has been performing observation campaigns of high-energy radiation in coastal areas of Japan Sea. Winter thunderstorms in Japan have unique characteristics such as frequent positive-polarity discharges, large discharge current, and low cloud bases. These features allow us to observe both long-duration gamma-ray bursts and lightning-triggered short-duration bursts at sea level. In 2015, we started a mapping observation project using multiple detectors at several new observation sites. We have developed brand-new portable gamma-ray detectors and deployed in the Kanazawa and Komatsu areas as well as the existing site at Kashiwazaki. During three winter seasons from 2015, we have detected 27 long-duration bursts and 8 short-duration bursts. The improved observation network in Kashiwazaki enables us to discover that the short-duration bursts are attributed to atmospheric photonuclear reactions triggered by a downward terrestrial gamma-ray flash. Collaborating with electric-field and radio-band measurements, we have also revealed a relation between abrupt termination of a long-duration burst and a lightning discharge. We demonstrate that the mapping observation project has been providing us clues to understand high-energy atmospheric phenomena associated with thunderstorm activities.
Coal mines are globally an important source of methane and also one of the largest point sources of methane. We present a high-resolution 0.1deg x 0.1deg bottom-up gridded emission inventory for methane emissions from coal mines in India and Australia, which are among the top five coal-producing countries in 2018. The aim is to reduce the uncertainty in local coal mine methane emissions and to improve the spatial localization to support monitoring and mitigation of these emissions. For India, we improve the spatial allocation of the emissions by identifying the exact location of surface and underground coal mines and, we use a tier-2 Intergovernmental Panel on Climate Change (IPCC) methodology to estimate the emissions from each coal mine using country-specific measured emission factors. For Australia, we estimate the emission for each coal mine by distributing the state-level reported total emissions using proxies of coal production and the coal basin-specific gas content profile of underground mines. Comparison of our total coal mine methane emission from India with existing global inventories showed our estimates are about a factor 3 lower, but well within the range of the national Indian estimate reported to the United Nations framework convention on climate change (UNFCCC). For both countries, the new spatial distribution of the emissions shows a large difference from the global inventories. Our improved emissions dataset will be useful for air quality or climate modeling and while assessing the satellite methane observations.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
