Raman lidar measurements for boundary layer gradients and atmospheric refraction of millimeter-wave signals

2020 ◽  
Author(s):  
Hans D. Hallen ◽  
C. Russell Philbrick
Keyword(s):  
Boundary Layer ◽  
Millimeter Wave ◽  
Raman Lidar ◽  
Atmospheric Refraction ◽  
Lidar Measurements

Lidar measurements accuracy of the hydrofluoride molecules concentration in the atmospheric boundary layer

2020 ◽  
pp. 29-33
Author(s):  
V.E. Privalov ◽  
V.G. Shemanin
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Relative Error ◽  
Concentration Level ◽  
Photon Counting ◽  
Raman Lidar ◽  
Height Range ◽  
Lidar Measurements ◽  
Counting Mode ◽  
Photon Counting Mode

The Raman lidar measurements accuracy of hydrofluoride molecules in the atmospheric boundary layer has been estimated in the work at the concentration level of 1014 сm–3and higher in the height range up to 1,5 km in the synchronous photon counting mode. It is received that it can measure the studied molecules concentration at the level of 1,5∙1014 сm–3 with the concentration measurement relative error lesser than 25 % at the 405 nm wavelength and the ranging distance up to 500 m by such a lidar.

scholarly journals Three years of routine Raman lidar measurements of tropospheric aerosols: Planetary boundary layer heights, extinction and backscatter coefficients

2002 ◽  
Vol 2 (1) ◽  
pp. 75-107
Author(s):  
J. Schneider ◽  
R. Eixmann
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Raman Lidar ◽  
Data Set ◽  
Air Mass ◽  
Mean Values ◽  
Boundary Layer Height ◽  
Lidar Measurements ◽  
The Mean ◽  
Air Mass Origin

Abstract. We have performed a three-year series of routine lidar measurements on a climatological base. To obtain an unbiased data set, the measurements were taken at preselected times. The measurements were performed between 1 December 1997, and 30 November 2000, at Kühlungsborn, Germany (54°07' N, 11°46' E). Using a Rayleigh/Mie/Raman lidar system, we measured the aerosol backscatter coefficients at three wavelengths in and above the planetary boundary layer. The aerosol extinction coefficient has been determined at 532 nm, but here the majority of the measurements has been restricted to heights above the boundary layer. Only after-sunset measurements are included in this data set since the Raman measurements were restricted to darkness. For the climatological analysis, we selected the cloud-free days out of a fixed measurement schedule. The annual cycle of the boundary layer height has been found to have a phase shift of about 25 days with respect to the summer/winter solstices. The mean values of the extinction and backscatter coefficients do not show significant annual differences. The backscatter coefficients in the planetary boundary layer were found to be about 10 times higher than above. The mean aerosol optical depth above the boundary layer and below 5 km is 0.26 (±1.0)  x 10-2 in summer, and 1.5 (±0.95)  x 10-2 in winter, which almost negligible compared to values measured in the boundary layer. A cluster analysis of the backward trajectories yielded two major directions of air mass origin above the planetary boundary layer and 4 major directions inside. A marked difference between the total aerosol load dependent on the air mass origin could be found for air masses originating from the west and travelling at high wind speeds. Comparing the measured spectral dependence of the backscatter coefficients with data from the Global Aerosol Data Set, we found a general agreement, but only a few conclusions with respect to the aerosol type could be draws due to the high variability of the measured backscatter coefficients.

scholarly journals EARLINET dust observations vs. BSC-DREAM8b modeled profiles: 12-year-long systematic comparison at Potenza, Italy

2014 ◽  
Vol 14 (16) ◽  
pp. 8781-8793 ◽  
Author(s):  
L. Mona ◽  
N. Papagiannopoulos ◽  
S. Basart ◽  
J. Baldasano ◽  
I. Binietoglou ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Saharan Dust ◽  
Raman Lidar ◽  
Dust Layer ◽  
Systematic Comparison ◽  
Dust Extinction ◽  
Lidar Measurements ◽  
Order Of Magnitude ◽  
Lidar Ratio ◽  
532 Nm

Abstract. In this paper, we report the first systematic comparison of 12-year modeled dust extinction profiles vs. Raman lidar measurements. We use the BSC-DREAM8b model, one of the most widely used dust regional models in the Mediterranean, and Potenza EARLINET lidar profiles for Saharan dust cases, the largest one-site database of dust extinction profiles. A total of 310 dust cases were compared for the May 2000–July 2012 period. The model reconstructs the measured layers well: profiles are correlated within 5% of significance for 60% of the cases and the dust layer center of mass as measured by lidar and modeled by BSC-DREAM8b differ on average 0.3 ± 1.0 km. Events with a dust optical depth lower than 0.1 account for 70% of uncorrelated profiles. Although there is good agreement in terms of profile shape and the order of magnitude of extinction values, the model overestimates the occurrence of dust layer top above 10 km. Comparison with extinction profiles measured by the Raman lidar shows that BSC-DREAM8b typically underestimates the dust extinction coefficient, in particular below 3 km. Lowest model–observation differences (below 17%) correspond to a lidar ratio at 532 nm and Ångström exponent at 355/532 nm of 60 ± 13 and 0.1 ± 0.6 sr, respectively. These are in agreement with values typically observed and modeled for pure desert dust. However, the highest differences (higher than 85%) are typically related to greater Ångström values (0.5 ± 0.6), denoting smaller particles. All these aspects indicate that the level of agreement decreases with an increase in mixing/modification processes.

scholarly journals A Lidar at Clermont-Ferrand—France to describe the boundary layer dynamics, aerosols, cirrus and tropospheric water vapor

2018 ◽  
Vol 176 ◽  
pp. 05047
Author(s):  
J.L. Baray ◽  
P. Fréville ◽  
N. Montoux ◽  
A. Chauvigné ◽  
D. Hadad ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
Vertical Profiles ◽  
Raman Lidar ◽  
Tropospheric Aerosols ◽  
Boundary Layer Dynamics

A Rayleigh-Mie-Raman LIDAR provides vertical profiles of tropospheric variables at Clermont-Ferrand (France) since 2008, in order to describe the boundary layer dynamics, tropospheric aerosols, cirrus and water vapor. It is included in the EARLINET network. We performed hardware/software developments in order to upgrade the quality, calibration and improve automation. We present an overview of the system and some examples of measurements and a preliminary geophysical analysis of the data.

scholarly journals Lidar-based remote sensing of atmospheric boundary layer height over land and ocean

2014 ◽  
Vol 7 (1) ◽  
pp. 173-182 ◽  
Author(s):  
T. Luo ◽  
R. Yuan ◽  
Z. Wang
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Marine Boundary Layer ◽  
Mixing Layer ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Lidar Measurements ◽  
Mixing Layer Height ◽  
Atmospheric Radiation Measurement ◽  
Atmospheric Boundary Layer Height

Abstract. Atmospheric boundary layer (ABL) processes are important in climate, weather and air quality. A better understanding of the structure and the behavior of the ABL is required for understanding and modeling of the chemistry and dynamics of the atmosphere on all scales. Based on the systematic variations of the ABL structures over different surfaces, different lidar-based methods were developed and evaluated to determine the boundary layer height and mixing layer height over land and ocean. With Atmospheric Radiation Measurement Program (ARM) Climate Research Facility (ACRF) micropulse lidar (MPL) and radiosonde measurements, diurnal and season cycles of atmospheric boundary layer depth and the ABL vertical structure over ocean and land are analyzed. The new methods are then applied to satellite lidar measurements. The aerosol-derived global marine boundary layer heights are evaluated with marine ABL stratiform cloud top heights and results show a good agreement between them.

scholarly journals Graphics algorithm for deriving atmospheric boundary layer heights from CALIPSO data

2018 ◽  
Vol 11 (9) ◽  
pp. 5075-5085 ◽  
Author(s):  
Boming Liu ◽  
Yingying Ma ◽  
Jiqiao Liu ◽  
Wei Gong ◽  
Wei Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Weather Forecasting ◽  
Correlation Coefficients ◽  
Horizontal Resolution ◽  
Backscatter Coefficient ◽  
Distribution Method ◽  
Boundary Layer Height ◽  
Lidar Measurements ◽  
Ground Based Lidar

Abstract. The atmospheric boundary layer is an important atmospheric feature that affects environmental health and weather forecasting. In this study, we proposed a graphics algorithm for the derivation of atmospheric boundary layer height (BLH) from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data. Owing to the differences in scattering intensity between molecular and aerosol particles, the total attenuated backscatter coefficient 532 and attenuated backscatter coefficient 1064 were used simultaneously for BLH detection. The proposed algorithm transformed the gradient solution into graphics distribution solution to overcome the effects of large noise and improve the horizontal resolution. This method was then tested with real signals under different horizontal smoothing numbers (1, 3, 15 and 30). Finally, the results of BLH obtained by CALIPSO data were compared with the results retrieved by the ground-based lidar measurements. Under the horizontal smoothing number of 15, 12 and 9, the correlation coefficients between the BLH derived by the proposed algorithm and ground-based lidar were both 0.72. Under the horizontal smoothing number of 6, 3 and 1, the correlation coefficients between the BLH derived by graphics distribution method (GDM) algorithm and ground-based lidar were 0.47, 0.14 and 0.12, respectively. When the horizontal smoothing number was large (15, 12 and 9), the CALIPSO BLH derived by the proposed method demonstrated a good correlation with ground-based lidar. The algorithm provided a reliable result when the horizontal smoothing number was greater than 9. This finding indicated that the proposed algorithm can be applied to the CALIPSO satellite data with 3 and 5 km horizontal resolution.

scholarly journals Tropospheric water vapour and relative humidity profiles from lidar and microwave radiometry

2014 ◽  
Vol 7 (5) ◽  
pp. 1201-1211 ◽  
Author(s):  
F. Navas-Guzmán ◽  
J. Fernández-Gálvez ◽  
M. J. Granados-Muñoz ◽  
J. L. Guerrero-Rascado ◽  
J. A. Bravo-Aranda ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Vapour ◽  
Microwave Radiometer ◽  
Radiosonde Data ◽  
Mixing Ratio ◽  
Raman Lidar ◽  
Night Time ◽  
New Approach ◽  
Lidar Measurements ◽  
Humidity Profiles

Abstract. In this paper, we outline an iterative method to calibrate the water vapour mixing ratio profiles retrieved from Raman lidar measurements. Simultaneous and co-located radiosonde data are used for this purpose and the calibration results obtained during a radiosonde campaign in summer and autumn 2011 are presented. The water vapour profiles measured during night-time by the Raman lidar and radiosondes are compared and the differences between the methodologies are discussed. Then, a new approach to obtain relative humidity profiles by combination of simultaneous profiles of temperature (retrieved from a microwave radiometer) and water vapour mixing ratio (from a Raman lidar) is addressed. In the last part of this work, a statistical analysis of water vapour mixing ratio and relative humidity profiles obtained during 1 year of simultaneous measurements is presented.

Raman lidar measurements of Pinatubo aerosols over southeastern Kansas during November-December 1991

1992 ◽  
Vol 19 (15) ◽  
pp. 1599-1602 ◽  
Author(s):  
R. A. Ferrare ◽  
S. H. Melfi ◽  
D. N. Whiteman ◽  
K. D. Evans
Keyword(s):  
Raman Lidar ◽  
Lidar Measurements

scholarly journals Comparison of Large Eddy Simulations of a convective boundary layer with wind LIDAR measurements

2012 ◽  
Vol 8 (1) ◽  
pp. 83-86 ◽  
Author(s):  
J. G. Pedersen ◽  
M. Kelly ◽  
S.-E. Gryning ◽  
R. Floors ◽  
E. Batchvarova ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Geostrophic Wind ◽  
Large Eddy Simulations ◽  
Horizontal Wind ◽  
Convective Boundary ◽  
Horizontal Wind Speed ◽  
Large Eddy ◽  
Lidar Measurements ◽  
Wind Lidar

Abstract. Vertical profiles of the horizontal wind speed and of the standard deviation of vertical wind speed from Large Eddy Simulations of a convective atmospheric boundary layer are compared to wind LIDAR measurements up to 1400 m. Fair agreement regarding both types of profiles is observed only when the simulated flow is driven by a both time- and height-dependent geostrophic wind and a time-dependent surface heat flux. This underlines the importance of mesoscale effects when the flow above the atmospheric surface layer is simulated with a computational fluid dynamics model.

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