A5038107137- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Wind and Air Flow Studies
- Vehicle emissions and performance
- Remote Sensing and LiDAR Applications
- Urban Heat Island Mitigation
- Atmospheric Ozone and Climate
- Climate variability and models
- Arctic and Antarctic ice dynamics
- Advanced Optical Sensing Technologies
- Precipitation Measurement and Analysis
- Advanced Measurement and Detection Methods
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Plant Water Relations and Carbon Dynamics
- Solar Radiation and Photovoltaics
- Air Traffic Management and Optimization
- Geophysics and Gravity Measurements
- Environmental and Agricultural Sciences
- Geophysical Methods and Applications
- Ocular and Laser Science Research
Vaisala (United States)
2011-2017
Abstract. The mixing layer is an important meteorological factor that affects air pollution. In this study, the atmospheric height (MLH) was observed in Beijing from July 2009 to December 2012 using a ceilometer. By comparison with radiosonde data, we found ceilometer underestimates MLH under conditions of neutral stratification caused by strong winds, whereas it overestimates when sand-dust crossing. Using meteorological, PM2.5, and PM10 observational screened automatically; observations...
Abstract. The implementation of emission reductions during the 2014 Asia-Pacific Economic Cooperation (APEC) summit provides a valuable opportunity to study air pollution in Beijing. From 15 October 30 November 2014, height atmospheric mixing layer and vertical attenuated backscattering coefficient profiles were observed online using a~lidar ceilometer. Compared with fine particulate matter (PM2.5) aerosol optical depth (AOD) data, coefficients measured by lidar ceilometer strongly...
Abstract. Ceilometer lidars are used for cloud base height detection, to probe aerosol layers in the atmosphere (e.g. detection of elevated Saharan dust or volcanic ash), and examine boundary layer dynamics. Sensor optics acquisition algorithms can strongly influence observed attenuated backscatter profiles; therefore, physical interpretation profiles requires careful application corrections. This study addresses widely deployed Vaisala CL31 ceilometer. Attenuated studied evaluate impact...
Abstract. To investigate the spatiotemporal variability of mixing layer height (MLH) on North China Plain (NCP), multi-site and long-term observations MLH with ceilometers at three inland stations (Beijing, BJ; Shijiazhuang, SJZ; Tianjin, TJ) one coastal site (Qinhuangdao) were conducted from 16 October 2013 to 15 July 2015. The in NCP highest summer lowest winter, while area Bohai was spring. As a typical southern Hebei, annual mean SJZ 464 ± 183 m, which 15.0 21.9 % lower than that BJ (594...
Abstract. The mixing layer height (MLH) is a measure for the vertical turbulent exchange within boundary layer, which one of controlling factors dilution pollutants emitted near ground. Based on continuous MLH measurements with Vaisala CL51 ceilometer and from an air quality network, relationship between near-surface pollutant concentrations has been investigated. In this context uncertainty retrievals representativeness ground-based in situ are crucial. We have investigated topic by using...
Abstract To investigate regional haze formation, ceilometer observations at the Beijing (BJ), Shijiazhuang (SJZ), Tianjin (TJ), and Qinhuangdao (QHD) stations were conducted from 12 October to 10 November 2014, obtain boundary layer height (BLH) attenuated backscattering coefficients (ABC). Particles four highly correlated, whereas precursors of particles exhibited weaker correlations. By analyzing typical episode between 21 26 we found that warm advection a 850 hPa Loess Plateau caused...
Abstract. The spatial structure and the progression speed of first ash layer from Icelandic Eyjafjallajökull volcano which reached Germany on 16/17 April is investigated remote sensing data numerical simulations. ceilometer network German Meteorological Service was able to follow over whole Germany. This turned out be a rather shallow only several hundreds metres thickness oriented slantwise in middle troposphere brought downward by large-scale sinking motion Southern Alps. Special Raman...
Abstract. In this study 1 year of ceilometer measurements taken in the Kathmandu Valley, Nepal, framework SusKat project (A Sustainable Atmosphere for Valley) were analysed to investigate diurnal variation mixing layer height (MLH) and its dependency on meteorological conditions. addition, impact MLH temporal magnitude measured black carbon concentrations are each season. Based assumption that aerosols vertically well mixed within finding varies only little during night time morning hours,...
On 4 days in summer and winter the mixing layer height over municipal area of Munich, Germany, was determined by several remote sensing instruments situ probes. The main motivation to obtain information on aerosols, therefore we decided understand as that where most locally produced aerosols are concentrated. In this paper wanted investigate potential quite different methodologies which depend measurements aerosol properties those do not. operation two lidars, a ceilometer,...
Automatic mixing layer height monitoring was performed by continuous sodar and ceilometer measurements in the Inn valley east of Innsbruck, Austria during a winter measuring campaign on air noise pollution.The ceilometer, an eye-safe commercial lidar originally designed to detect cloud base heights vertical visibility for aviation safety purposes, operated about two months; more than four months.Special software this provides routine retrievals multiple aerosol layers from optical...
U rban air quality assessment requires the knowledge of temporal and spatial structure mixing layer, because this controls vertical dilution near-surface pollutants. The behaviour layer is a consequence temperature moisture profiles in lower atmosphere so that remote sensing can be suitable tool to monitor it. Three ceilometers, Vaisala LD40 two CL31, have been operated for many months German city Augsburg order observe aerosol distribution. Wind profile information obtained part period from...
Abstract. A series of major eruptions the Eyjafjallajökull volcano in Iceland started on 14 April 2010 and continued until end May 2010. The volcanic emissions moved over nearly whole Europe were observed first 16 Southern Germany with different remote sensing systems from ground space. Enhanced PM10 SO2 concentrations detected 17 at mountain stations (Zugspitze/Schneefernerhaus Schauinsland) as well Innsbruck by situ measurement devices. On 19 intensive vertical mixing advection along...
Abstract The performance of a novel water vapor broadband differential absorption lidar (BB-DIAL) is evaluated. This compact, eye-safe, diode-laser-based prototype was developed by Vaisala. It designed to operate unattended in all weather conditions and provide height-resolved measurements mixing ratio the lower troposphere. Evaluation Vaisala carried out at U.S. Department Energy’s Atmospheric Radiation Measurement site north-central Oklahoma (i.e., Southern Great Plains site) from 15 May...
Helsinki Testbed is a research project of mesoscale meteorology. Data from various meteorological sensors including five lidar ceilometers situated in and around have been collected since 2005. The report attenuated backscatter profiles that evaluated respect mixing height determination. Two different methods, gradient method an idealized applied for this purpose. examples situations are discussed. enhanced single lens optical concept the improves their ability to detect nocturnal stable...
Abstract The depth of the aerosol layer at Villum Research Station Nord in high Arctic is analysed based on 8 years observations from a ceilometer and one full year wind lidar. particular interest for process modelling atmospheric chemistry studies. assigned to inflection point attenuated backscatter profile by two methods; polynomial approximation other direct numerical differentiation. analysis types hourly profiles; consists averaging computing median. Due sporadic occurrence outliers...
The sensitivity of commercial lidar ceilometers for detecting aerosols within the boundary layer is sufficient to give reliable information on parameters like mixing height. traditional optical concepts these lidars are either biaxial two-lens systems or one-lens with separate compensation techniques internal cross talk. single lens concept superior system when data from near range up 300 m elevation required. This paper introduces an enhanced removing cross-talk between laser transmitter...
The Vaisala ceilometer LD40 is an eye-safe commercial lidar. It designed originally to detect cloud base heights and vertical visibility for aviation safety purposes. instrument was operated continuously at different measurement campaigns mixing layer height from aerosol backscatter profiles. First results with the CT25K were presented last year in paper SPIE 5235-64 environmental measuring campaign frame of BMBF-funded project VALIUM Hanover, Germany, investigating air pollution a street...
Ultrafine particles (UFP; diameter less than 100 nm) are ubiquitous in urban air, and an acknowledged risk to human health. At the same time, little is known about immission situation at typical sites such as high-traffic roads, residential areas with a high amount of solid fuels for home heating or commercial industrial due missing legal requirements measurements UFP. Therefore, UFP were measured evaluated (sub-)urban background well on spots influenced by these various anthropogenic local...
Investigation of the atmospheric boundary-layer structure in urban areas can be challenged by landscape complexity and heterogenous conditions this instills. Stuttgart, Germany, is a city situated bowl-shaped basin troubled accumulation pollutants during weak-wind conditions. The center Stuttgart surrounded steep slopes up to 250 m above floor, except for an opening northeast that allows runoff towards Neckar river. Urban planning regulation air quality require advanced monitoring...