High concentrations of ozone (O3) is a major air problem in urban areas, which creates serious threat to human health. Urban street canyon morphology plays key role pollutant dispersion and photochemical reaction rate. In this study, one-year observation at three height levels was performed investigate the O3 distribution vertically Shenyang. Then, field investigation ENVI-met modelling were co...

Using 1 km satellite remote sensing observations, this paper examines the clouds, aerosols, water vapor and surface skin temperature over Beijing to understand the possible urban system contributions to the extreme rainfall event on 21 July 2012 (i.e., 721 event). Remote sensing measurements, with the advantage of high spatial resolution and coverage, reveal three key urban-related mechanisms: ...

Precise positioning of an automobile to within lane-level precision can enable better navigation and context-awareness. However, GPS by itself cannot provide such precision in obstructed urban environments. In this paper, we present a system called CARLOC for lanelevel positioning of automobiles. CARLOC uses three key ideas in concert to improve positioning accuracy: it uses digital maps to mat...

Using mobile smart devices to provide urban location-based services (LBS) with sub-meter-level accuracy (around 0.5 m) is a major application field for future global navigation satellite system (GNSS) development. Real-time kinematic (RTK) positioning, which is a widely used GNSS-based positioning approach, can improve the accuracy from about 10-20 m (achieved by the standard positioning servic...

Tree is an essential factor affecting airflow and pollutant diffusion in the urban street canyon. The wind environment canyon will be effectively improved by expounding mechanism implementing greening measures. Moreover, it help decrease concentration around This paper reviews numerical simulation under tree influence. Firstly, mathematical model used for canyons influence of trees summarized. ...

Wintertime temperature profiles in the Grand Canyon exhibit a neutral to isothermal stratification during both daytime and nighttime, with only rare instances of actual temperature inversions. The canyon warms during daytime and cools during nighttime more or less uniformly through the canyon’s entire depth. This weak stability and temperature structure evolution differ from other Rocky Mountai...

The performance of Global Navigation Satellite Systems (GNSS) can be improved in certain environments (e.g. indoor or urban scenarios) by using additional complementary systems, such as the use of wireless communications signals. Indeed, multicarrier wireless systems provide many advantages for the integration of both communications and positioning capabilities, such as the Long Term Evolution ...

The recent development in vehicle-to-everything (V2X) communication opens a new opportunity to improve the positioning performance of road users. We explore benefit connecting raw data global navigation satellite system (GNSS) from agents. In urban areas, GNSS is highly degraded due signal blockage and reflection. 3D building model can play major role mitigating multipath non-line-of-sight (NLO...

Circulation over coastal submarine canyons driven by constant upwelling or downwelling wind stress is simulated and analyzed with a primitive equation ocean model. Astoria Canyon, on the west coast of North America, is the focus of this study, and model results are consistent with most major features of mean canyon circulation observed in Astoria Canyon. Near-surface flow crosses over the canyo...

Catastrophic outburst floods carved amphitheater-headed canyons on Earth and Mars, and the steep headwalls of these canyons suggest that some formed by upstream headwall propagation through waterfall erosion processes. Because topography evolves in concert with water flow during canyon erosion, we suggest that bedrock canyon morphology preserves hydraulic information about canyon-forming floods...