Long-term aerosol and cloud database from correlative EARLINET-CALIPSO observations

The European Aerosol Research Lidar Network, EARLINET, performs correlative observations during CALIPSO overpasses based on a sophisticated measurement strategy since June 2006. Within a dedicated activity supported by the European Space Agency (ESA), sixteen EARLINET stations contributed about 1500 measurements during an intensive observational period from May 2008 to October 2009. From these measurements, we establish a long-term aerosol and cloud database of correlative EARLINET-CALIPSO observations. This database shall provide a basis for homogenizing long-term space-borne observations conducted with different lidar instruments operating at different wavelengths on various platforms over the next decade(s). The database is also used to study the quality and representativeness of satellite lidar cross sections along an orbit against long-term lidar network observations on a continental scale.Postprint (published version

Chapter Long-Distance LIDAR Mapping Schematic for Fast Monitoring of Bioaerosol Pollution over Large City Areas

Light detection and ranging (LIDAR) atmospheric sensing is a major tool for remote monitoring of aerosol pollution and its propagation in the atmosphere. Combining LIDAR sensing with ground-based aerosol monitoring can form the basis of integrated air-quality characterization. When present, biological atmospheric contamination is transported by aerosol particles of different size known as bioaerosol, whose monitoring is now among the basic areas of atmospheric research, especially in densely-populated large urban regions, where many bioaerosol-emitting sources exist. Thus, promptly identifying the bioaerosol sources, including their geographical coordinates, intensities, space-time distributions, etc., becomes a major task of a city monitoring system. This chapter argues in favor of integrating a LIDAR mapping schematic with in situ sampling and characterization of the bioaerosol in the urban area. The measurements, data processing, and decision-making aimed at preventing further atmospheric contamination should be performed in a near-real-time mode, which imposes certain demands on the typical LIDAR schematics, including long-range sensing as a critical parameter, especially over large areas (10 – 100 km2). In this chapter, we describe experiments using a LIDAR schematic allowing near-real-time long-distance measurements of urban bioaerosol combined with its ground-based sampling and physicochemical and biological studies

Coordinated lidar observations of Saharan dust over Europe in the frame of EARLINET-ASOS project during CALIPSO overpasses: a strong dust case study analysis with modeling support

Coordinated lidar observations of Saharan dust over Europe are performed in the frame of the EARLINETASOS (2006-2011) project, which comprises 25 stations: 16 Raman lidar stations, including 8 multiwavelength (3+2 station) Raman lidar stations, are used to retrieve the aerosol microphysical properties. Since the launch of CALIOP, the two-wavelength lidar on board the CALIPSO satellite (June 2006) our lidar network has been performing correlative aerosol measurements during CALIPSO overpasses over the individual stations. In our presentation, we report on the correlative measurements obtained during Saharan dust intrusions in the period from June 2006 to June 2008. We found that the number of dust events is generally greatest in late spring, summer and early autumn periods, mainly in southern and south-eastern Europe. A measurement example is presented that was analyzed to show the potential of a ground based lidar network to follow a dust event over a specific study area, in correlation with the CALIOP measurements. The dust transport over the studied area was simulated by the DREAM forecast model. Cross-section analyses of CALIOP over the study area were used to assess the model performance for describing and forecasting the vertical and horizontal distribution of the dust field over the Mediterranean. Our preliminary results can be used to reveal the importance of the synergy between the CALIOP measurement and the dust model, assisted by ground-based lidars, for clarifying the overall transport of dust over the European continent

Investigation of representativeness of CALIPSO aerosol optical properties products by EARLINET correlative measurements

The almost six-years long database of aerosol and cloud vertical profiles provided by CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) is at the present the longest database of aerosol optical properties at global scale. This database is a unique tool for the characterization of aerosol 4D distribution at global scale. However, CALIPSO has a small footprint and a revisiting time of 16 days, and therefore how well these measurements represent the atmospheric conditions of a surrounding area over a longer time is a big issue to be investigated. Because of its geographic coverage and the large number of advanced Raman aerosol lidars, EARLINET, the European Aerosol Research Lidar Network, offers a unique opportunity for the validation and full exploitation of the CALIPSO mission. CALIPSO Level 2 and Level 3 data products are investigated in terms of their representativeness by comparison with EARLINET measurements. Comparisons for the Level 2 profiles available in both version 2 (40 km as horizontal resolution) and version 3 (5 km) releases highlight the issue of finding a best compromise between the high resolution and the high signal-to-noise ratio. Representativeness of monthly averages provided in Level 3 data is investigated using EARLINET-CALIPSO correlative measurements. The study will furthermore benefit from the availability of the 12-years long-term database of EARLINET climatological data available from May 2000.Peer ReviewedPostprint (published version

Investigation of representativeness of CALIPSO aerosol optical properties products by EARLINET correlative measurements

The almost six-years long database of aerosol and cloud vertical profiles provided by CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) is at the present the longest database of aerosol optical properties at global scale. This database is a unique tool for the characterization of aerosol 4D distribution at global scale. However, CALIPSO has a small footprint and a revisiting time of 16 days, and therefore how well these measurements represent the atmospheric conditions of a surrounding area over a longer time is a big issue to be investigated. Because of its geographic coverage and the large number of advanced Raman aerosol lidars, EARLINET, the European Aerosol Research Lidar Network, offers a unique opportunity for the validation and full exploitation of the CALIPSO mission. CALIPSO Level 2 and Level 3 data products are investigated in terms of their representativeness by comparison with EARLINET measurements. Comparisons for the Level 2 profiles available in both version 2 (40 km as horizontal resolution) and version 3 (5 km) releases highlight the issue of finding a best compromise between the high resolution and the high signal-to-noise ratio. Representativeness of monthly averages provided in Level 3 data is investigated using EARLINET-CALIPSO correlative measurements. The study will furthermore benefit from the availability of the 12-years long-term database of EARLINET climatological data available from May 2000.Peer Reviewe

Coordinated lidar observations of Saharan dust over Europe in the frame of EARLINET-ASOS project during CALIPSO overpasses: A case study analysis with modeling support

Coordinated lidar observations of Saharan dust over Europe are performed in the frame of the EARLINETASOS (2006-2011) project, which comprises 25 stations: 16 Raman lidar stations, including 8 multiwavelength (3+2 station) Raman lidar stations, are used to retrieve the aerosol microphysical properties. Since the launch of CALIOP, the two-wavelength lidar on board the CALIPSO satellite (June 2006) our lidar network has been performing correlative aerosol measurements during CALIPSO overpasses over the individual stations. In our presentation, we report on the correlative measurements obtained during Saharan dust intrusions in the period from June 2006 to June 2008. We found that the number of dust events is generally greatest in late spring, summer and early autumn periods, mainly in southern and south-eastern Europe. A measurement example is presented that was analyzed to show the potential of a ground based lidar network to follow a dust event over a specific study area, in correlation with the CALIOP measurements. The dust transport over the studied area was simulated by the DREAM forecast model. Cross-section analyses of CALIOP over the study area were used to assess the model performance for describing and forecasting the vertical and horizontal distribution of the dust field over the Mediterranean. Our preliminary results can be used to reveal the importance of the synergy between the CALIOP measurement and the dust model, assisted by ground-based lidars, for clarifying the overall transport of dust over the European continent

Long-term aerosol and cloud database from space-borne lidar and ground-based lidar network observations

In June 2006, the satellite-borne lidar CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) began its observations onboard CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations; Winker et al., 2007). This date is regarded the starting point of a unique long-term, global, 4-dimensional aerosol and cloud data set. The forthcoming missions ADM-Aeolus (Atmospheric Dynamics Mission; Stoffelen et al., 2005; Ansmann et al., 2006) of the European Space Agency ESA and EarthCARE (Earth Clouds, Aerosols, and Radiation Explorer) of ESA and the Japan Aerospace Exploration Agency JAXA (ESA, 2004), with their lidar instruments ALADIN (Atmospheric Laser Doppler Lidar Instrument) and ATLID (Atmospheric Lidar), respectively, will continue such kind of observations. It is expected that the long-term data set gained in this way will substantially improve our knowledge on the role of aerosols and clouds in the Earth's climate system.Peer Reviewe

Long-term aerosol and cloud database from space-borne lidar and ground-based lidar network observations

In June 2006, the satellite-borne lidar CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) began its observations onboard CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations; Winker et al., 2007). This date is regarded the starting point of a unique long-term, global, 4-dimensional aerosol and cloud data set. The forthcoming missions ADM-Aeolus (Atmospheric Dynamics Mission; Stoffelen et al., 2005; Ansmann et al., 2006) of the European Space Agency ESA and EarthCARE (Earth Clouds, Aerosols, and Radiation Explorer) of ESA and the Japan Aerospace Exploration Agency JAXA (ESA, 2004), with their lidar instruments ALADIN (Atmospheric Laser Doppler Lidar Instrument) and ATLID (Atmospheric Lidar), respectively, will continue such kind of observations. It is expected that the long-term data set gained in this way will substantially improve our knowledge on the role of aerosols and clouds in the Earth's climate system.Peer ReviewedPostprint (published version