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Atmospheric lidar

About: Atmospheric lidar is a research topic. Over the lifetime, 224 publications have been published within this topic receiving 3935 citations.


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TL;DR: A restatement of the more general solution of Fernald et al.l which is also applicable to mildly turbid atmospheres where both aerosol and molecular scatterers must be considered in the analysis.
Abstract: There have been many discussions of solutions to the lidar equation for elastic scattering (e.g., Fernald et al.,' Klett, 2 Davis, and Collis and Russell ). Most of these are simply variations on Hitschfeld and Bordan's5 solution for meteorological radars. Klett 2 recently restated this solution in a very convenient form for the analysis of lidar observations collected in very turbid atmospheres. His paper has prompted a restatement of the more general solution of Fernald et al.l which is also applicable to mildly turbid atmospheres where both aerosol and molecular scatterers must be considered in the analysis. This has led to a simple numerical scheme for the computer analysis of lidar measurements. The lidar equation for two distinct classes of scatters (Fernald et al.') is

1,558 citations

Book
01 Jan 1984
TL;DR: In this article, the authors present an analysis and interpretation of the Lidar Return Signals, as well as a discussion of the application of LIDAR in hydrographic and atmospheric applications.
Abstract: Electromagnetic Theory of Radiation. Quantum Physics and Radiation Processes. Interaction and Propagation of Radiation. Laser Fundamentals. Laser Systems as Remote Sensors. Laser-Remote-Sensor Equations. Analysis and Interpretation of the Lidar Return Signals. Atmospheric Lidar Applications. Hydrographic Lidar Applications. Concluding Remarks. Index.

717 citations

Journal ArticleDOI
TL;DR: In this article, a noctilucent cloud (NLC) was observed from a midlatitude site (Logan, Utah) on the evenings of 22 and 23 June 1999 mountain daylight time.
Abstract: [1] Noctilucent clouds (NLCs) were observed from a midlatitude site (Logan, Utah) on the evenings of 22 and 23 June 1999 mountain daylight time. On both nights the clouds were seen for approximately an hour by experienced observers, and they were photographed. The NLC was also observed on the second evening for approximately an hour in the zenith with the Rayleigh-scatter lidar at the Atmospheric Lidar Observatory, which is operated by the Center for Atmospheric and Space Sciences on the campus of Utah State University. These observations enabled several of the properties of the cloud to be determined. They were within the range of those observed at higher latitudes, but notably the NLC was very weak and thin. These combined visual and lidar observations unequivocally support the identification of the cloud as a noctilucent cloud. The midlatitude location (41.74°N, 111.81°W) is ∼10° equatorward of previous observations. This equatorward penetration is significant because of potential implications about global change or the global circulation.

271 citations

Journal ArticleDOI
TL;DR: In this paper, a long-term study of PBL top heights and PBL growth rates in South Africa was conducted using ground-based and satellite LIDAR measurements, and the results indicated that the ECMWF model agreed the best with mean relative difference of 15.4%, while the second best correlation was with the SAWS model with corresponding difference of 20.1%.
Abstract: . Atmospheric lidar measurements were carried out at Elandsfontein measurement station, on the eastern Highveld approximately 150 km east of Johannesburg in South Africa throughout 2010. The height of the planetary boundary layer (PBL) top was continuously measured using a Raman lidar, PollyXT (POrtabLe Lidar sYstem eXTended). High atmospheric variability together with a large surface temperature range and significant seasonal changes in precipitation were observed, which had an impact on the vertical mixing of particulate matter, and hence, on the PBL evolution. The results were compared to radiosondes, CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) space-borne lidar measurements and three atmospheric models that followed different approaches to determine the PBL top height. These models included two weather forecast models operated by ECMWF (European Centre for Medium-range Weather Forecasts) and SAWS (South African Weather Service), and one mesoscale prognostic meteorological and air pollution regulatory model TAPM (The Air Pollution Model). The ground-based lidar used in this study was operational for 4935 h during 2010 (49% of the time). The PBL top height was detected 86% of the total measurement time (42% of the total time). Large seasonal and diurnal variations were observed between the different methods utilised. High variation was found when lidar measurements were compared to radiosonde measurements. This could be partially due to the distance between the lidar measurements and the radiosondes, which were 120 km apart. Comparison of lidar measurements to the models indicated that the ECMWF model agreed the best with mean relative difference of 15.4%, while the second best correlation was with the SAWS model with corresponding difference of 20.1%. TAPM was found to have a tendency to underestimate the PBL top height. The wind speeds in the SAWS and TAPM models were strongly underestimated which probably led to underestimation of the vertical wind and turbulence and thus underestimation of the PBL top height. Comparison between ground-based and satellite lidar shows good agreement with a correlation coefficient of 0.88. On average, the daily maximum PBL top height in October (spring) and June (winter) was 2260 m and 1480 m, respectively. To our knowledge, this study is the first long-term study of PBL top heights and PBL growth rates in South Africa.

80 citations

Journal ArticleDOI
TL;DR: The Mars Orbiter Laser Altimeter (MOLA) instrument operated as an atmospheric lidar system as well as an altimeter, detecting absorptive clouds in northern latitudes shortly after orbit insertion in October 1997 and reflective clouds over the north polar cap at the start of the Science Phasing Orbits in March 1998.
Abstract: [1] The Mars Orbiter Laser Altimeter (MOLA) instrument operated as an atmospheric lidar system as well as an altimeter, detecting absorptive clouds in northern latitudes shortly after orbit insertion in October 1997 and reflective clouds over the north polar cap at the start of the Science Phasing Orbits in March 1998. Global cloud measurements commenced with the primary mapping mission in March 1999, with nearly continuous coverage for 1.25 Mars years. MOLA tracked several dust storms, culminating with a major dust storm in June 2001. Reflective clouds, exhibiting distinctive patterns governed by insolation and the dynamics of the atmosphere, were detected at elevations up to 20 km above the surface, chiefly in the polar winter night. MOLA distinguishes cloud returns by pulse width and energy measurements. Unusually strong and brief reflections with minimal extinction suggest precipitation of CO2 snow under supercooled conditions. Weaker cloud reflections occurred at all latitudes. Some reflective daylight clouds at low latitudes suggested convective vortices or “dust devils.” Ground fogs composed of dust and H2O ice formed at night along the seasonal frost line. Absorptive clouds, while not resolved altimetrically, tracked the advancing and receding edges of the seasonal polar caps. The absorptive and reflective clouds provide a seasonal profile of atmospheric activity spanning two Martian years. Winter reflective cloud activity declined to background levels earlier in the second year at both poles, suggesting interannual warming.

75 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20218
20207
201912
201812
201720
201620