A NEW, HIGH-PERFORMANCE, HETERODYNE SPECTROMETER FOR GROUND-BASED REMOTE SENSING OF MESOSPHERIC WATER VAPOUR

2011 ◽  
pp. 569-578 ◽  
Author(s):  
K. HALLGREN ◽  
P. HARTOGH ◽  
C. JARCHOW
Keyword(s):  
Remote Sensing ◽  
Water Vapour ◽  
High Performance ◽  
Heterodyne Spectrometer

Spectral characteristics of leafy spurge (Euphorbia esula) leaves and flower bracts

Weed Science ◽  
2004 ◽  
Vol 52 (4) ◽  
pp. 492-497 ◽  
Author(s):  
E. Raymond Hunt ◽  
James E. McMurtrey ◽  
Amy E. Parker Williams ◽  
Lawrence A. Corp
Keyword(s):  
Remote Sensing ◽  
High Performance ◽  
Near Infrared ◽  
Spectral Characteristics ◽  
Leafy Spurge ◽  
Hyperspectral Remote Sensing ◽  
Total Carotenoids ◽  
Physiological Basis ◽  
Infrared Wavelengths ◽  
Pigment Concentrations

Leafy spurge can be detected during flowering with either aerial photography or hyperspectral remote sensing because of the distinctive yellow-green color of the flower bracts. The spectral characteristics of flower bracts and leaves were compared with pigment concentrations to determine the physiological basis of the remote sensing signature. Compared with leaves of leafy spurge, flower bracts had lower reflectance at blue wavelengths (400 to 500 nm), greater reflectance at green, yellow, and orange wavelengths (525 to 650 nm), and approximately equal reflectances at 680 nm (red) and at near-infrared wavelengths (725 to 850 nm). Pigments from leaves and flower bracts were extracted in dimethyl sulfoxide, and the pigment concentrations were determined spectrophotometrically. Carotenoid pigments were identified using high-performance liquid chromatography. Flower bracts had 84% less chlorophylla, 82% less chlorophyllb, and 44% less total carotenoids than leaves, thus absorptance by the flower bracts should be less and the reflectance should be greater at blue and red wavelengths. The carotenoid to chlorophyll ratio of the flower bracts was approximately 1:1, explaining the hue of the flower bracts but not the value of reflectance. The primary carotenoids were lutein, β-carotene, and β-cryptoxanthin in a 3.7:1.5:1 ratio for flower bracts and in a 4.8:1.3:1 ratio for leaves, respectively. There was 10.2 μg g−1fresh weight of colorless phytofluene present in the flower bracts and none in the leaves. The fluorescence spectrum indicated high blue, red, and far-red emission for leaves compared with flower bracts. Fluorescent emissions from leaves may contribute to the higher apparent leaf reflectance in the blue and red wavelength regions. The spectral characteristics of leafy spurge are important for constructing a well-documented spectral library that could be used with hyperspectral remote sensing.

scholarly journals Quality assessment of water cycle parameters in REMO by Radar-Lidar synergy

2007 ◽  
Vol 7 (3) ◽  
pp. 8455-8524
Author(s):  
B. Hennemuth ◽  
A. Weiss ◽  
J. Bösenberg ◽  
D. Jacob ◽  
H. Linné ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Heat Flux ◽  
Soil Moisture ◽  
Water Content ◽  
Water Vapour ◽  
Water Cycle ◽  
Sensible Heat Flux ◽  
Regional Model ◽  
Cloud Base ◽  
Cloud Radar

Abstract. A comparison study of water cycle parameters derived from ground-based remote-sensing instruments and from the regional model REMO is presented. Observational data sets were collected during three measuring campaigns in summer/autumn 2003 and 2004 at Richard Aßmann Observatory, Lindenberg, Germany. The remote sensing instruments which were used are differential absorption lidar, Doppler lidar, ceilometer, cloud radar, and micro rain radar for the derivation of humidity profiles, ABL height, water vapour flux profiles, cloud parameters, and rain rate. Additionally, surface latent and sensible heat flux and soil moisture were measured. Error ranges and representativity of the data are discussed. For comparisons the regional model REMO was run for all measuring periods with a horizontal resolution of 18 km and 33 vertical levels. Parameter output was every hour. The measured data were transformed to the vertical model grid and averaged in time in order to better fit with gridbox model values. The comparisons show that the atmospheric boundary layer is not adequately simulated, on most days it is too shallow and too moist. This is found to be caused by a wrong partitioning of energy at the surface, particularly a too large latent heat flux. The reason is obviously an overestimation of soil moisture during drying periods by the one-layer scheme in the model. The profiles of water vapour transport within the ABL appear to be realistically simulated. The comparison of cloud cover reveals an underestimation of low-level and mid-level clouds by the model, whereas the comparison of high-level clouds is hampered by the inability of the cloud radar to see cirrus clouds above 10 km. Simulated ABL clouds apparently have a too low cloud base, and the vertical extent is underestimated. The ice water content of clouds agree in model and observation whereas the liquid water content is unsufficiently derived from cloud radar reflectivity in the present study. Rain rates are similar, but the representativeness of both observations and grid box values is low.

Characterization of the time evolution of the PBL structure and dry-layers based on the us of Raman Lidar measurements collected during HYMEX-SOP1

2021 ◽  
Author(s):  
Donato Summa ◽  
Paolo Di Girolamo ◽  
Noemi Franco ◽  
Benedetto De Rosa ◽  
Fabio Madonna ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Boundary Layer ◽  
Water Vapour ◽  
Planetary Boundary Layer ◽  
Grid Point ◽  
Laser Source ◽  
Raman Lidar ◽  
Water Vapour Concentration ◽  
Vapour Concentration

<p>The exchange processes between the Earth and the atmosphere play a crucial role in the development of the Planetary Boundary Layer (PBL). Different remote sensing techniques can provide PBL measurement with different spatial and temporal resolutions. Vertical profiles of atmospheric thermodynamic variables, i.e.  temperature and humidity, or wind speed, clouds and aerosols can be used as proxy to retrieve PBL height from active and passive remote sensing instruments. The University of BASILicata ground-based Raman Lidar system (BASIL) was deployed in the North-Western Mediterranean basin in the Cévennes-Vivarais site (Candillargues, Southern France, Lat: 43°37' N, Long: 4° 4' E, Elev: 1 m) and operated between 5 September and 5 November 2012, collecting more than 600 hours of measurements, distributed over 51 days and 19 intensive observation periods (IOPs). BASIL is capable to provide high-resolution and accurate measurements of atmospheric temperature and water vapour, both in daytime and night-time, based on the application of the rotational and vibrational Raman lidar techniques in the UV. This measurement capability makes BASIL a key instrument for the characterization of the water vapour concentration. BASIL makes use of a Nd:YAG laser source capable of emitting pulses at 355, 532 and 1064 nm, with a single pulse energy at 355nm of 500 mJ [1] .In the presented research effort, water vapour concentration was  computed and used to determine the PBL height. [2]. A dynamic index  included in the European Centre for Medium-range Weather Forecasts (ECMWF) ERA5 atmospheric reanalysis (CAPE, Friction velocity, etc.) is also considered and compared with BASIL resutls. ERA5 provides hourly data on regular latitude-longitude grids at 0.25° x 0.25° resolution at 37 pressure levels [3]. ERA5 is publicly available through the Copernicus Climate Data Store (CDS, https://cds.climate.copernicus.eu).  In order to properly carry out the comparison, the nearest ERA5 grid point to the lidar site has been considered assuming the representativeness uncertainty due to the use of the nearest grid-point comparable with other methods (e.g. kriging, bilinear interpolation, etc.). More results from this  measurement  effort will  be reported and discussed at the Conference.</p><p><strong>Reference</strong></p><p>[1] Di Girolamo, Paolo, De Rosa, Benedetto, Flamant, Cyrille, Summa, Donato, Bousquet, Olivier, Chazette, Patrick, Totems, Julien, Cacciani, Marco. Water vapor mixing ratio and temperature inter-comparison results in the framework of the Hydrological Cycle in the Mediterranean Experiment—Special Observation Period 1. BULLETIN OF ATMOSPHERIC SCIENCE AND TECHNOLOGY, ISSN: 2662-1495, doi: 10.1007/s42865-020-00008-3</p><p>[2] D. Summa, P. Di Girolamo, D. Stelitano, and M. Cacciani. Characterization of the planetary boundary layer height and structure by Raman lidar: comparison of different approaches  Atmos. Meas. Tech., 6, 3515–3525, 2013 www.atmos-meas-tech.net/6/3515/2013/doi:10.5194/amt-6-3515-2013</p><p>[3] Hersbach et al. The ERA5 global reanalysis Hans  https://doi.org/10.1002/qj.3803[3]</p>

Hygric Properties of HPC with Natural Pozzolana

2016 ◽  
Vol 677 ◽  
pp. 93-97 ◽  
Author(s):  
Jaroslava Koťátková ◽  
Monika Čáchová ◽  
Dana Koňáková ◽  
Eva Vejmelková
Keyword(s):  
Water Vapour ◽  
High Performance ◽  
High Performance Concrete ◽  
Diffusion Resistance ◽  
Supplementary Cementitious Material ◽  
Water Vapour Transport ◽  
Water Vapour Diffusion ◽  
Natural Pozzolana ◽  
Vapour Diffusion ◽  
Liquid Water Transport

The water vapour transport and the liquid water transport of high performance concrete (HPC) with the content of natural pozzolana are the described in this paper. Studied properties are presented by means of water vapour diffusion coefficient, water vapour diffusion resistance factor and absorption coefficient respectively. The natural pozzolana (NP), namely natural zeolite, is used as supplementary cementitious material which affects the durability properties of the end product. The obtained results revealed the effectiveness of NP in the terms of both studied properties when used in small amounts, i.e. at about 20% of cement weight. On the other hand substitutions higher than 40% result in worsening of the resistance of the concrete to water and water vapour ingress and its movement trough the material.

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