scholarly journals Remote sensing of aerosol optical properties and solar heating rate by the combination of sky radiometer and lidar measurements

2017 ◽  
Author(s):  
Rei Kudo ◽  
Tomoaki Nishizawa ◽  
Toshinori Aoyagi ◽  
Yasushi Fujiyoshi ◽  
Yuji Higuchi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Heating Rate ◽  
Solar Heating ◽  
Aerosol Optical Properties ◽  
Lidar Measurements

scholarly journals Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

2016 ◽  
Author(s):  
Rei Kudo ◽  
Tomoaki Nishizawa ◽  
Toshinori Aoyagi
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Heating Rate ◽  
Extinction Coefficient ◽  
Single Scattering ◽  
Solar Heating ◽  
Asymmetry Factor ◽  
Vertical Profiles ◽  
Aerosol Optical Properties ◽  
Lidar Measurements

Abstract. The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements, and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust were well estimated but not those of transported pollution aerosol. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties between SKYLIDAR and SKYRAD.PACK retrievals, and the surface solar irradiance calculated from the SKYLIDAR retrievals was compared with pyranometer measurement. The results showed good agreements: The columnar values of the SKYLIDAR retrievals agreed with reliable SKYRAD.PACK retrievals, and the SKYLIDAR retrievals were sufficiently accurate to evaluate the surface solar irradiance.

scholarly journals Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

2016 ◽  
Vol 9 (7) ◽  
pp. 3223-3243 ◽  
Author(s):  
Rei Kudo ◽  
Tomoaki Nishizawa ◽  
Toshinori Aoyagi
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Heating Rate ◽  
Extinction Coefficient ◽  
Single Scattering ◽  
Solar Heating ◽  
Asymmetry Factor ◽  
Vertical Profiles ◽  
Aerosol Optical Properties ◽  
Lidar Measurements

Abstract. The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust, but not those of transported pollution aerosol, were well estimated. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties retrieved with the SKYLIDAR algorithm to those produced with the more established scheme SKYRAD.PACK, and the surface solar irradiance calculated from the SKYLIDAR retrievals was compared with pyranometer measurement. The results showed good agreements: the columnar values of the SKYLIDAR retrievals agreed with reliable SKYRAD.PACK retrievals, and the SKYLIDAR retrievals were sufficiently accurate to evaluate the surface solar irradiance.

scholarly journals Remote sensing of aerosols with small satellites in formation flight

2018 ◽  
Vol 11 (7) ◽  
pp. 3935-3954 ◽  
Author(s):  
Kirk Knobelspiesse ◽  
Sreeja Nag
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Information Content ◽  
Systems Engineering ◽  
Limited Information ◽  
Aerosol Optical Properties ◽  
Small Satellites ◽  
Analysis Technique ◽  
Technological Developments ◽  
Aerosol Remote Sensing

Abstract. Determination of aerosol optical properties with orbital passive remote sensing is a difficult task, as observations often have limited information. Multi-angle instruments, such as the Multi-angle Imaging SpectroRadiometer (MISR) and the POlarization and Directionality of the Earth's Reflectances (POLDER), seek to address this by making information-rich multi-angle observations that can be used to better retrieve aerosol optical properties. The paradigm for such instruments is that each angle view is made from one platform, with, for example, a gimballed sensor or multiple fixed view angle sensors. This restricts the observing geometry to a plane within the scene bidirectional reflectance distribution function (BRDF) observed at the top of the atmosphere (TOA). New technological developments, however, support sensors on small satellites flying in formation, which could be a beneficial alternative. Such sensors may have only one viewing direction each, but the agility of small satellites allows one to control this direction and change it over time. When such agile satellites are flown in formation and their sensors pointed to the same location at approximately the same time, they could sample a distributed set of geometries within the scene BRDF. In other words, observations from multiple satellites can take a variety of view zenith and azimuth angles and are not restricted to one azimuth plane as is the case with a single multi-angle instrument. It is not known, however, whether this is as potentially capable as a multi-angle platform for the purposes of aerosol remote sensing. Using a systems engineering tool coupled with an information content analysis technique, we investigate the feasibility of such an approach for the remote sensing of aerosols. These tools test the mean results of all geometries encountered in an orbit. We find that small satellites in formation are equally capable as multi-angle platforms for aerosol remote sensing, as long as their calibration accuracies and measurement uncertainties are equivalent. As long as the viewing geometries are dispersed throughout the BRDF, it appears the quantity of view angles determines the information content of the observations, not the specific observation geometry. Given the smoothly varying nature of BRDF's observed at the TOA, this is reasonable and supports the viability of aerosol remote sensing with small satellites flying in formation. The incremental improvement in information content that we found with number of view angles also supports the concept of a resilient mission comprised of multiple satellites that are continuously replaced as they age or fail.

The aerosol optical properties measurement by ground remote sensing in Zhejiang, China

2009 ◽  
Author(s):  
Bin Wang ◽  
Hong Jiang ◽  
Jian Chen ◽  
Zishan Jiang ◽  
Shuquan Yu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Aerosol Optical Properties

scholarly journals Joint elastic side-scattering LIDAR and Raman LIDAR measurements of aerosol optical properties in south east Colorado

2017 ◽  
Vol 12 (03) ◽  
pp. P03008-P03008 ◽  
Author(s):  
L. Wiencke ◽  
V. Rizi ◽  
M. Will ◽  
C. Allen ◽  
A. Botts ◽  
...  
Keyword(s):  
Optical Properties ◽  
Raman Lidar ◽  
Aerosol Optical Properties ◽  
Lidar Measurements

Ground-based remote sensing of aerosol optical properties in one city in Northwest China

2008 ◽  
Vol 89 (1-2) ◽  
pp. 194-205 ◽  
Author(s):  
Jianjun Liu ◽  
Youfei Zheng ◽  
Zhanqing Li ◽  
Rongjun Wu
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Northwest China ◽  
Aerosol Optical Properties

scholarly journals Identifying Chemical Aerosol Signatures using Optical Suborbital Observations: How much can optical properties tell us about aerosol composition?

2021 ◽  
Author(s):  
Meloë S. F. Kacenelenbogen ◽  
Qian Tan ◽  
Sharon P. Burton ◽  
Otto P. Hasekamp ◽  
Karl D. Froyd ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Air Quality ◽  
Chemical Transport ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Aerosol Optical Properties ◽  
Aerosol Composition ◽  
Ångström Exponent

Abstract. Improvements in air quality and Earth’s climate predictions require improvements of the aerosol speciation in chemical transport models, using observational constraints. Aerosol speciation (e.g., organic aerosols, black carbon, sulfate, nitrate, ammonium, dust or sea salt) is typically determined using in situ instrumentation. Continuous, routine surface network aerosol composition measurements are not uniformly widespread over the globe. Satellites, on the other hand, can provide a maximum coverage of the horizontal and vertical atmosphere but observe aerosol optical properties (and not aerosol speciation) based on remote sensing instrumentation. Combinations of satellite-derived aerosol optical properties can inform on air mass aerosol types (AMTs e.g., clean marine, dust, polluted continental). However, these AMTs are subjectively defined, might often be misclassified and are hard to relate to the critical parameters that need to be refined in models. In this paper, we derive AMTs that are more directly related to sources and hence to speciation. They are defined, characterized, and derived using simultaneous in situ gas-phase, chemical and optical instruments on the same aircraft during the Study of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS, US, summer of 2013). First, we prescribe well-informed AMTs that display distinct aerosol chemical and optical signatures to act as a training AMT dataset. These in situ observations reduce the errors and ambiguities in the selection of the AMT training dataset. We also investigate the relative skill of various combinations of aerosol optical properties to define AMTs and how much these optical properties can capture dominant aerosol speciation. We find distinct optical signatures for biomass burning (from agricultural or wildfires), biogenic and dust-influence AMTs. Useful aerosol optical properties to characterize these signatures are the extinction angstrom exponent (EAE), the single scattering albedo, the difference of single scattering albedo in two wavelengths, the absorption coefficient, the absorption angstrom exponent (AAE), and the real part of the refractive index (RRI). We find that all four AMTs studied when prescribed using mostly airborne in situ gas measurements, can be successfully extracted from at least three combinations of airborne in situ aerosol optical properties (e.g., EAE, AAE and RRI) over the US during SEAC4RS. However, we find that the optically based classifications for BB from agricultural fires and polluted dust include a large percentage of misclassifications that limit the usefulness of results relating to those classes. The technique and results presented in this study are suitable to develop a representative, robust and diverse source-based AMT database. This database could then be used for widespread retrievals of AMTs using existing and future remote sensing suborbital instruments/networks. Ultimately, it has the potential to provide a much broader observational aerosol data set to evaluate chemical transport and air quality models than is currently available by direct in situ measurements. This study illustrates how essential it is to explore existing airborne datasets to bridge chemical and optical signatures of different AMTs, before the implementation of future spaceborne missions (e.g., the next generation of Earth Observing System (EOS) satellites addressing Aerosol, Cloud, Convection and Precipitation (ACCP) designated observables).

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