scholarly journals Study of Persistent Haze Pollution in Winter over Jinan (China) Based on Ground-Based and Satellite Observations

2021 ◽  
Vol 13 (23) ◽  
pp. 4862
Author(s):  
Hui Li ◽  
Rui Shi ◽  
Shikuan Jin ◽  
Weiyan Wang ◽  
Ruonan Fan ◽  
...  
Keyword(s):  
Formation Process ◽  
Regional Climate ◽  
Inversion Layer ◽  
Satellite Observation ◽  
Pollutant Emissions ◽  
Observation Data ◽  
Pressure System ◽  
Haze Pollution ◽  
The Government

A comprehensive study of the formation process of haze events in the Jinan area of China during winter is conducted based on the ground-based and satellite observation data from 1 December 2020 to 12 January 2021. According to variation of pollutant concentrations, two typical types of haze pollution are found in the Jinan area. During the type 1 haze pollution, the PM2.5 concentrations are greater than 75 μgm−3 and less than 115 μgm−3 with a short duration. The haze is mainly caused by local pollutant emissions and the accumulation of pollutants transported from areas around Jinan. By contrast, type 2 haze pollution episodes have a long duration and peak PM2.5 concentrations between 150 μgm−3 and 250 μgm−3, which is considered heavy pollution. Type 2 haze pollution is mainly caused by a mixture of long-range transported dust with locally emitted pollutants. Moreover, the unfavorable meteorological factors such as stable inversion layer, continuous cold high-pressure system, high relative humidity, and low wind speed play an important role in the formation of both types of haze pollution. In addition, there are significant photochemical processes during the haze pollutions. According to satellite data, the AOD in Jinan and surrounding areas is maintained at a high-level during haze pollution. It indicates that the local pollution is often accompanied by regional pollution during haze pollution events. This study reveals the formation process of haze pollution and promotes the study of regional climate change, which can provide guidance to the government in the prevention and control of haze pollution in East China.

scholarly journals Elevated 3D structures of PM<sub>2.5</sub> and impact of complex terrain-forcing circulations on heavy haze pollution over Sichuan Basin, China

2021 ◽  
Vol 21 (11) ◽  
pp. 9253-9268
Author(s):  
Zhuozhi Shu ◽  
Yubao Liu ◽  
Tianliang Zhao ◽  
Junrong Xia ◽  
Chenggang Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Sichuan Basin ◽  
Southwest China ◽  
Pollutant Emissions ◽  
Atmospheric Environment ◽  
Observation Data ◽  
Free Troposphere ◽  
Near Surface ◽  
Haze Pollution ◽  
The Impact

Abstract. Deep basins create uniquely favorable conditions for causing air pollution, and the Sichuan Basin (SCB) in Southwest China is such a basin featuring frequent heavy pollution. A wintertime heavy haze pollution event in the SCB was studied with conventional and intensive observation data and the WRF-Chem model to explore the 3D distribution of PM2.5 to understand the impact of regional pollutant emissions, basin circulations associated with plateaus, and downwind transport to the adjacent areas. It was found that the vertical structure of PM2.5 over the SCB was characterized by a remarkable hollow sandwiched by high PM2.5 layers at heights of 1.5–3 km and a highly polluted near-surface layer. The southwesterlies over the Tibetan Plateau (TP) and Yunnan-Guizhou Plateau (YGP) resulted in a lee vortex over the SCB, which helped form and maintain heavy PM2.5 pollution. The basin PM2.5 was lifted into the free troposphere and transported outside of the SCB. At the bottom of the SCB, high PM2.5 concentrations were mostly located in the northwestern and southern regions. Due to the blocking effect of the plateau terrain on the northeasterly winds, PM2.5 gradually increased from northeast to southwest in the basin. In the lower free troposphere, the high PM2.5 centers were distributed over the northwestern and southwestern SCB areas, as well as the central SCB region. For this event, the regional emissions from the SCB contributed 75.4 %–94.6 % to the surface PM2.5 concentrations in the SCB. The SCB emissions were the major source of PM2.5 over the eastern regions of the TP and the northern regions of the YGP, with contribution rates of 72.7 % and 70.5 %, respectively, during the dissipation stage of heavy air pollution over the SCB, which was regarded as the major pollutant source affecting atmospheric environment changes in Southwest China.

scholarly journals High-resolution smoke forecasting for the 2018 Camp Fire in California

2021 ◽  
Keyword(s):  
Anthropogenic Pollution ◽  
Satellite Observation ◽  
Test Case ◽  
Observation Data ◽  
Fire Event ◽  
Pressure System ◽  
Fire Smoke ◽  
Radiative Power ◽  
The Impact ◽  
First Time

Abstract Smoke from the 2018 Camp Fire in Northern California blanketed a large part of the region for two weeks, creating poor air quality in the “unhealthy” range for millions of people. The NOAA Global System Laboratory’s HRRR-Smoke model was operating experimentally in real time during the Camp Fire. Here, output from the HRRR-Smoke model is compared to surface observations of PM2.5 from AQS and PurpleAir sensors as well as satellite observation data. The HRRR-Smoke model grid at 3-km resolution successfully simulated the evolution of the plume during the initial phase of the fire (8-10 November 2018). Stereoscopic satellite plume height retrievals were used to compare with model output (for the first time, to the authors’ knowledge), showing that HRRR-Smoke is able to represent the complex 3D distribution of the smoke plume over complex terrain. On 15-16 November, HRRR-Smoke was able to capture the intensification of PM2.5 pollution due to a high pressure system and subsidence that trapped smoke close to the surface; however, HRRR-Smoke later underpredicted PM2.5 levels due to likely underestimates of the fire radiative power (FRP) derived from satellite observations. The intensity of the Camp Fire smoke event and the resulting pollution during the stagnation episodes make it an excellent test case for HRRR-Smoke in predicting PM2.5 levels, which were so high from this single fire event that the usual anthropogenic pollution sources became insignificant. The HRRR-Smoke model was implemented operationally at NOAA/NCEP in December 2020, now providing essential support for smoke forecasting as the impact of US wildfires continues to increase in scope and magnitude.

scholarly journals Elevated 3D structures of PM<sub>2.5</sub> and impact of complex terrain-forcing circulations on heavy haze pollution over Sichuan Basin, China

2020 ◽  
Author(s):  
Zhuozhi Shu ◽  
Yubao Liu ◽  
Tianliang Zhao ◽  
Junrong Xia ◽  
Chenggang Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Sichuan Basin ◽  
Southwest China ◽  
Pollutant Emissions ◽  
Atmospheric Environment ◽  
Observation Data ◽  
Free Troposphere ◽  
Near Surface ◽  
Haze Pollution ◽  
The Impact

Abstract. Deep basins create a uniquely favorable condition for the formation of air pollution, and the Sichuan Basin (SCB) in Southwest China is such a basin featuring frequent heavy pollution. A wintertime heavy haze pollution event in SCB was studied with conventional and intensive observation data and the WRF-chem model to explore the three-dimensional distribution of PM2.5 for understanding the impact of regional pollutant emissions, basin circulations associated with plateaus, and downwind transport to the adjacent areas. It was found that the vertical structure of PM2.5 over SCB was characterized with a remarkable hollow sandwiched by high PM2.5 layers at heights of 1.5–3 km and the highly polluted near-surface layer. The southwesterlies passed over the Tibetan Plateau (TP) and Yunan-Guizhou Plateau (YGP) resulted in a lee vortex over SCB, which helped form and maintain heavy PM2.5 pollution. The basin PM2.5 was lifted into the free troposphere and transported outside of SCB. At the bottom of SCB, high PM2.5 concentrations were mostly located in the northwest and southern regions. Due to the blocking effect of the plateau terrain on the northeasterly winds, PM2.5 gradually increased from northeast to southwest in the basin. In the lower free troposphere, the high PM2.5 centers were distributed over the northwestern and southwestern SCB areas, as well as the central SCB region. For this event, the regional emissions from SCB contributed 75.4–94.6 % to the surface PM2.5 concentrations in SCB. The SCB emission export was the major source of the PM2.5 over the eastern regions of TP and the northern regions of YGP, with contribution rates of 72.7 % and 70.5 %, respectively, during the dissipation stage of heavy air pollution over SCB, which was regarded as the major pollutant sources affecting atmospheric environment changes in Southwest China.

scholarly journals Comparison of ISS–CATS and CALIPSO–CALIOP Characterization of High Clouds in the Tropics

2020 ◽  
Vol 12 (23) ◽  
pp. 3946
Author(s):  
Pasquale Sellitto ◽  
Silvia Bucci ◽  
Bernard Legras
Keyword(s):  
Optical Properties ◽  
Space Station ◽  
Satellite Observation ◽  
Observation Data ◽  
Upper Troposphere ◽  
Cloud Properties ◽  
Synchronous Orbit ◽  
The Tropics ◽  
High Clouds

Clouds in the tropics have an important role in the energy budget, atmospheric circulation, humidity, and composition of the tropical-to-global upper-troposphere–lower-stratosphere. Due to its non-sun-synchronous orbit, the Cloud–Aerosol Transport System (CATS) onboard the International Space Station (ISS) provided novel information on clouds from space in terms of overpass time in the period of 2015–2017. In this paper, we provide a seasonally resolved comparison of CATS characterization of high clouds (between 13 and 18 km altitude) in the tropics with well-established CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, both in terms of clouds’ occurrence and cloud optical properties (optical depth). Despite the fact that cloud statistics for CATS and CALIOP are generated using intrinsically different local overpass times, the characterization of high clouds occurrence and optical properties in the tropics with the two instruments is very similar. Observations from CATS underestimate clouds occurrence (up to 80%, at 18 km) and overestimate the occurrence of very thick clouds (up to 100% for optically very thick clouds, at 18 km) at higher altitudes. Thus, the description of stratospheric overshoots with CATS and CALIOP might be different. While this study hints at the consistency of CATS and CALIOP clouds characterizaton, the small differences highlighted in this work should be taken into account when using CATS for estimating cloud properties and their variability in the tropics.

scholarly journals A signed network perspective on the government formation process in parliamentary democracies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angela Fontan ◽  
Claudio Altafini
Keyword(s):  
Decision Making ◽  
Formation Process ◽  
Signed Graph ◽  
Balance Theory ◽  
Collective Decision Making ◽  
Dynamical Models ◽  
Average Correlation ◽  
Parliamentary Democracies ◽  
Signed Network ◽  
The Government

AbstractIn parliamentary democracies, government negotiations talks following a general election can sometimes be a long and laborious process. In order to explain this phenomenon, in this paper we use structural balance theory to represent a multiparty parliament as a signed network, with edge signs representing alliances and rivalries among parties. We show that the notion of frustration, which quantifies the amount of “disorder” encoded in the signed graph, correlates very well with the duration of the government negotiation talks. For the 29 European countries considered in this study, the average correlation between frustration and government negotiation talks ranges between 0.42 and 0.69, depending on what information is included in the edges of the signed network. Dynamical models of collective decision-making over signed networks with varying frustration are proposed to explain this correlation.

Simulation of runoff for the Black Volta Basin using satellite observation data

2012 ◽  
Vol 10 (3) ◽  
pp. 245-254 ◽  
Author(s):  
Salamatu Shaibu ◽  
Samuel Nii Odai ◽  
Kwaku Amaning Adjei ◽  
Edward Matthew Osei ◽  
Frank Ohene Annor
Keyword(s):  
Satellite Observation ◽  
Observation Data ◽  
Volta Basin

Variational assimilation of observation data in the mathematical model of the Baltic Sea dynamics

2015 ◽  
Vol 30 (4) ◽  
Author(s):  
Valeriy I. Agoshkov ◽  
Eugene I. Parmuzin ◽  
Vladimir B. Zalesny ◽  
Victor P. Shutyaev ◽  
Natalia B. Zakharova ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Baltic Sea ◽  
Satellite Observation ◽  
Sea Surface ◽  
Observation Data ◽  
The Baltic Sea ◽  
Variational Assimilation ◽  
The Baltic ◽  
The Mathematical Model

AbstractA mathematical model of the dynamics of the Baltic Sea is considered. A problem of variational assimilation of sea surface temperature (SST) data is formulated and studied. Based on variational assimilation of satellite observation data, an algorithm solving the inverse problem of heat flux restoration on the interface of two media is proposed. The results of numerical experiments reconstructing the heat flux functions in the problem of variational assimilation of SST observation data are presented. The influence of SST assimilation on other hydrodynamic parameters of the model is considered.

scholarly journals Projected changes in haze pollution potential in China: an ensemble of regional climate model simulations

2017 ◽  
Vol 17 (16) ◽  
pp. 10109-10123 ◽  
Author(s):  
Zhenyu Han ◽  
Botao Zhou ◽  
Ying Xu ◽  
Jia Wu ◽  
Ying Shi
Keyword(s):  
Regional Climate Model ◽  
21St Century ◽  
Climate Model ◽  
Regional Climate ◽  
River Delta ◽  
Central China ◽  
Future Climate Change ◽  
Pollution Potential ◽  
Pollution Risk ◽  
Haze Pollution

Abstract. Based on the dynamic downscaling by the regional climate model RegCM4 from three CMIP5 global models under the historical and the RCP4.5 simulations, this article evaluated the performance of the RegCM4 downscaling simulations on the air environment carrying capacity (AEC) and weak ventilation days (WVDs) in China, which are applied to measure haze pollution potential. Their changes during the middle and the end of the 21st century were also projected. The evaluations show that the RegCM4 downscaling simulations can generally capture the observed features of the AEC and WVD distributions over the period 1986–2005. The projections indicate that the annual AEC tends to decrease and the annual WVDs tend to increase over almost the whole country except central China, concurrent with greater change by the late 21st century than by the middle of the 21st century. It suggests that annual haze pollution potential would be enlarged under the RCP4.5 scenario compared to the present. For seasonal change in the four main economic zones of China, it is projected consistently that there would be a higher probability of haze pollution risk over the Beijing–Tianjin–Hebei (BTH) region and the Yangtze River Delta (YRD) region in winter and over the Pearl River Delta (PRD) region in spring and summer in the context of the warming scenario. Over Northeast China (NEC), future climate change might reduce the AEC or increase the WVDs throughout the whole year, which favours the occurrence of haze pollution and thus the haze pollution risk would be aggravated. The relative contribution of different components related to the AEC change further indicates that changes in the boundary layer depth and the wind speed play leading roles in the AEC change over the BTH and NEC regions. In addition to those two factors, the precipitation change also exerts important impacts on the AEC change over the YRD and PRD zones.

scholarly journals Estimating the open biomass burning emissions in Central and Eastern China from 2003 to 2015 based on satellite observation

2018 ◽  
Author(s):  
Jian Wu ◽  
Shaofei Kong ◽  
Fangqi Wu ◽  
Yi Cheng ◽  
Shurui Zheng ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Annual Variation ◽  
Eastern China ◽  
Satellite Observation ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Burned Area ◽  
Management Policies ◽  
Straw Burning ◽  
Grassland Fire

Abstract. Open biomass burning (OBB) has significant impacts on air pollution, climate change and potential human health. OBB has raised wide attention but with few focus on the annual variation of pollutant emission. Central and Eastern China (CEC) is one of the most polluted regions in China. This study aims to provide a state-of the-art estimation of the pollutant emissions from OBB in CEC from 2003 to 2015, by adopting the satellite observation dataset (the burned area product (MCD64Al) and the active fire product (MCD14 ML)), local biomass data (updated biomass loading data and high-resolution vegetation data) and local emission factors. Monthly emissions of pollutants were estimated and allocated into a 1 × 1 km spatial grid for four types of OBB including grassland, shrubland, forest and cropland. From 2003 to 2015, the emissions from forest, shrubland and grassland fire burning had a minor annual variation whereas the emissions from crop straw burning steadily increased. The cumulative emissions of OC, EC, CH4, NOX, NMVOC, SO2, NH3, CO, CO2 and PM2.5 were 3.64 × 103, 2.87 × 102, 3.05 × 103, 1.82 × 103, 6.4 × 103, 2.12 × 102, 4.67 × 103, 4.59 × 104, 9.39 × 105 and 4.13 × 102 Gg in these years, respectively. For cropland, corn straw burning was the largest contributor for all pollutant emissions, by 84 %–96 %. Among the forest, shrubland, grassland fire burning, forest fire burning emissions contributed the most and emissions from grassland fire was negligible due to few grass coverage in this region. High pollutant emissions were populated in the connection area of Shandong, Henan, Jiangsu and Anhui, with emission intensity higher than 100 ton per pixel, which was related to the frequent agricultural activities in these regions. The monthly emission peak of pollutants occurred in summer and autumn harvest periods including May, June, September and October, at which period ~ 50 % of pollutants were emitted for OBB. This study highlights the importance in controlling the crops straw burning emission. From December to March of the next year, the crop residue burning emissions decreased, while the emissions from forest, shrubland and grassland exhibited their highest values, leading to another small peak emissions of pollutants. Obvious regional differences in seasonal variations of OBB were observed due to different local biomass types and environmental conditions. Rural population, agricultural output, local burning habits, anthropological activities and management policies are all influence factors for OBB emissions. The successful adoption of double satellite dataset for long term estimation of pollutants from OBB with a high spatial resolution can support the assessing of OBB on regional air-quality, especially for harvest periods or dry seasons. It is also useful to evaluate the effects of annual OBB management policies in different regions.

scholarly journals Performance of SEACLID/CORDEX-SEA multi-model experiments in simulating temperature and rainfall in Vietnam

2019 ◽  
Vol 41 (4) ◽  
pp. 374-387 ◽  
Author(s):  
Nguyen Thi Tuyet ◽  
Ngo Duc Thanh ◽  
Phan Van Tan
Keyword(s):  
Southeast Asia ◽  
Climate Models ◽  
Global Climate ◽  
Regional Climate ◽  
Global Climate Models ◽  
Red River ◽  
Observation Data ◽  
Red River Delta ◽  
North Central ◽  
Climate Downscaling

The study examined the performance of six regional climate experiments conducted under the framework of the Southeast Asia Regional Climate Downscaling/Coordinated Regional Climate Downscaling Experiment-Southeast Asia (SEACLID/CORDEX-SEA) project and their ensemble product (ENS) in simulating temperature at 2 m (T2m) and rainfall (R) in seven climatic sub-regions of Vietnam. The six experiments were named following the names of their driving Global Climate Models (GCMs), i.e., CNRM, CSIRO, ECEA, GFDL, HADG and MPI. The observation data for the period 1986–2005 from 66 stations in Vietnam were used to compare with the model outputs. Results showed that cold biases were prominent among the experiments and ENS well reproduced the seasonal cycle of temperature in the Northeast, Red River Delta, North Central and Central Highlands regions. For rainfall, all the experiments showed wet biases and CSIRO exhibited the best. A scoring system was elaborated to objectively rank the performance of the experiments and the ENS experiment was reported to be the best.

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