Application of LIDAR Technique and MM5-CMAQ Modeling Approach for the Assessment of Winter PM10 Air Pollution: A Case Study in Beijing, China

Abstract

This paper reports the use of LIDAR technique, vertical wind profiler (VWP) and the coupled MM5-CMAQ air quality modeling system to investigate a high PM 10 concentration episode occurred in Beijing, China during January 8-9, 2004. Through the regression analysis between the observed PM 10 concentrations and the observed extinction coefficients, the converting formulas from the LIDAR records to the PM 10 mass concentrations in Beijing have been found. Further, a 2-level-nested grid domain with spatial resolutions of 36 and 12 km have been designed and employed for this study, and the coupled MM5-CMAQ modeling system has then been evaluated using both the ground-level PM 10 observations and the vertical profiles of PM 10 deduced from the measured LIDAR extinction coefficients. Based on the verified modeling system, two emission scenarios were designed to quantitatively assess the trans-boundary PM 10 contributions from the surrounding provinces of Beijing. The results illustrated that the particulate matter buildup over the Beijing region was due to a number of factors, including pollutants brought in from its surrounding provinces by the southwest winds and the emission from local sources within Beijing. It indicates that while Beijing needs to take positive steps to reduce its own pollution emissions, much effort should also be placed on demanding more pollution reduction and better environmental performance from its surrounding provinces.

A numerical study of contributions to air pollution in Beijing during CAREBeijing-2006

“…Comparatively, the influences from regional sources on ozone were less pronounced, with maximum contributions of 28 % from Hebei, 27 % from Tianjin, and 24 % from Shandong province, but not at the same time. According to Chen et al (2007) of the MM5-CMAQ modeling with five emission scenarios in the months of January, April, July and October in 2002, much efforts should be placed on demanding more pollution reduction and better emission control from surrounding provinces, while Beijing needed to take positive steps to reduce itself own emissions. These methods commonly used to estimate the contribution of targeted emissions, highlight significant bias in non-linear source-receptor relationships analysis.…”

Design, Modeling and Finite Element Static Analysis of a New Two Axis Solar Tracker Using SolidWorks/COSMOSWorks

“…The overall structural design of the solar tracker Fig. 1 was modeled using mechanical design software, SolidWorks [6,7]. The solar tracker is made up by three parts.…”

“…Therefore, SolidWorks software is used to design the solar tracker through computer-aid design. SolidWorks is a type of three dimensions modeling software and it is being used in engineering widely [6]. It is provided with some functions, such as three dimensions virtual modeling design of components, three dimensions virtual assembly, design analysis (COSMOSWorks) and etc.…”