Abstract. We investigated aerosol hygroscopic growth property and its influence on scattering coefficient using M9003 nephelometers in coupling with humidity controlled inlet system at a rural site near Beijing mega-city from 24 April to 15 May 2006. Inlet relative was an increasing range of 40%–90% while factor coefficient, f(RH=80%) as ratio RH=80% "dry" (RH<40%) varied 1.07–2.35 during the measurement. Further analysis indicated that under dust episode, measured is 1.2±0.02, estimated...

Abstract. An online air pollutant tagged module has been developed in the Nested Air Quality Prediction Model System (NAQPMS) to investigate impact of local and regional sources on pollutants Beijing during Campaign Research 2006 (CAREBeijing-2006). The NAQPMS model shows high performance simulating sulfur dioxide (SO2), particulate matter (PM10), nitrogen (NO2), ozone (O3) with overall better agreements observations at urban sites than rural areas. With module, contributions from surface...

Abstract. In order to improve the surface ozone forecast over Beijing and surrounding regions, data assimilation method integrated into a high-resolution regional air quality model monitoring network are employed. Several advanced strategies based on ensemble Kalman filter designed adjust O3 initial conditions, NOx conditions emissions, VOCs emissions separately or jointly through assimilating observations. As result, adjusting precursor demonstrates potential improvement of 1-h almost as...

Recent studies on regional haze pollution over China come up in general with strong variability of main causes heavy polluted episodes, linkage local specificities, sources and characteristics. This paper therefore aims at elucidating the specific formation mechanisms observed episodes 1–15 November 2015 Northeast region considered as one biggest megacity clusters China. The mega-city cluster, including Heilong Jiang, Jilin Liaoning provinces, is adjacent to Russia north, Mongolian west,...

Abstract. Predicting air pollution events in the low atmosphere over megacities requires a thorough understanding of tropospheric dynamics and chemical processes, involving, notably, continuous accurate determination boundary layer height (BLH). Through intensive observations experimented Beijing (China) an exhaustive evaluation existing algorithms applied to BLH determination, persistent critical limitations are noticed, particular during polluted episodes. Basically, under weak thermal...

Abstract. This study investigates a cross-variable ozone data assimilation (DA) method based on an ensemble Kalman filter (EnKF) that has been used in the companion to improve forecasts over Beijing and surrounding areas. The main purpose is delve into impacts of adjustment nitrogen oxide (NOx) emissions dioxide (NO2) this region during 2008 Olympic Games. A mixed effect NO2 was observed through application approach real-data (RDA) experiments. improved almost half urban sites with...

Acid rain has already been the environment issue for past century and is still concerned in Southern Eastern China. However, Northeastern China, considered as non-acid area, reported high frequency of acid occurred recently. Through a measurement model simulation analysis with linear regression technique, factor speciation, backward trajectory, source-tracing fraction sampling methods, this study aims to investigate causes frequently two cities (i.e., Dandong Dalian) identify contributing...

The Nested Air Quality Prediction Modeling System (NAQPMS), in coupling with the fifth-generation NCAR/Penn State Mesoscale Model (MM5), is employed to assess impact of vehicle traffic restriction on air quality Beijing within pre-Olympic environmental measures implemented from 17th 20th August 2007. Predictions are compared against meteorological and observed data validation shows model good performance as a whole. Sensitivity experiments, including baseline control scenarios, designed...

In air quality forecasting systems, failure to consider the considerably large anthropogenic heat emissions generated daily in Beijing megacity by intensive human activities is one of major causes model failure. this paper, we employ nested prediction system coupled with weather research and an urban canopy integrate over into modeling exhaustively evaluate their potential effects on forecast analyzing wind field, boundary layer structure (height atmospheric circulation), surface vertical...

Abstract. We performed ozone data assimilation by simultaneously adjusting the initial conditions, precursor conditions and emissions based on Ensemble Kalman Filter (EnKF) assessed its impacts modeling forecasting in Beijing nearby regions. A high-resolution regional air quality model a newly established monitoring network covering surrounding areas were employed. At each cycle, forecast error covariance was sampled from set of ensembles that generated perturbing emissions, photolysis rates...

Abstract. We investigated aerosol hygroscopic growth property and its influence on scattering coefficient using M9003 nephelometers in coupling with a relative humidity controlled inlet system at rural site near Beijing mega-city (Jingjintang) from 24th April to15th May 2006. Inlet was an increasing range of 40%–90% while the factor, f(RH=80%), varied 1.07–2.35 during measurement. Estimated periodic mean values factors are 1.27–1.34, 1.17–1.23, 1.55–1.59 2.33–2.48 for clean, dust, urban...

Abstract. An online air pollutant tagged module has been developed in the Nested Air Quality Prediction Model System (NAQPMS) to investigate impact of local and regional sources on pollutants Beijing during Campaign Research 2006 (CAREBeijing-2006). The NAQPMS model shows high performance simulating sulfur dioxide (SO2), particulate matter (PM10), nitrogen (NO2), ozone (O3) with overall better agreements observations at urban sites than rural areas. With module, contributions from surface...

Abstract. Predicting air pollution events in low atmosphere over megacities requires thorough understanding of the tropospheric dynamic and chemical processes, involving notably, continuous accurate determination boundary layer height (BLH). Through intensive observations experimented Beijing (China), an exhaustive evaluation existing algorithms applied to BLH determination, persistent critical limitations are noticed, particular polluted episodes. Basically, under weak thermal convection...

<p><span><span>Predicting air pollution events in the low atmosphere over megacities requires a thorough understanding of tropospheric dynamics and chemical processes, involving, notably, continuous accurate determination boundary layer height (BLH). Through intensive observations experimented Beijing (China) an exhaustive evaluation existing algorithms applied to BLH determination, persistent critical limitations are noticed, particular during...

Abstract. This study investigates a cross-variable ozone data assimilation (DA) method based on an ensemble Kalman filter (EnKF) that has been validated as efficient approach for improving forecasts. The main purpose is to delve into the impacts of adjustment nitrogen oxides (NOx) emissions dioxide (NO2) forecasts over Beijing and surrounding regions during 2008 Olympic Games. A mixed effect NO2 was observed application in real-data (RDA) experiments. improved forecast almost half urban...