scholarly journals Water vapor and aerosol lidar measurements within an atmospheric instrumental super site to study the aerosols and the tropospheric trace gases in rome

2018 ◽  
Vol 176 ◽  
pp. 05050
Author(s):  
D. Dionisi ◽  
A.M. Iannarelli ◽  
A. Scoccione ◽  
G.L. Liberti ◽  
M. Cacciani ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Vapor ◽  
Trace Gases ◽  
Atmospheric Parameters ◽  
Passive Remote Sensing ◽  
Wide Range ◽  
Lidar Measurements ◽  
Set Up

A joint instrumental Super Site, combining observation in urban (“Sapienza” University) and semi-rural (ESA-ESRIN and CNR-ISAC) environment, for atmospheric studies and satellites Cal/Val activities, has been set-up in the Rome area (Italy). Ground based active and passive remote sensing instruments located in both sites are operating in synergy, offering information for a wide range of atmospheric parameters. In this work, a comparison of aerosol and water vapor measurements derived by the Rayleigh-Mie-Raman (RMR) lidars, operating simultaneously in both experimental sites, is presented.

scholarly journals Comparative Studies for the Assessment of the Quality of Near-Real-Time GPS-Derived Atmospheric Parameters

2008 ◽  
Vol 25 (5) ◽  
pp. 701-714 ◽  
Author(s):  
R. Pacione ◽  
F. Vespe
Keyword(s):  
Water Vapor ◽  
Standard Deviation ◽  
Real Time ◽  
Weather Prediction ◽  
Neutral Atmosphere ◽  
Atmospheric Parameters ◽  
Total Delay ◽  
Zenith Total Delay ◽  
Wide Range

Abstract Accurate and frequent sampling of atmospheric parameters, such as water vapor, is important for enabling reliable weather forecasts and global climate studies over a wide range of spatial and temporal scales. Recent developments in global positioning system data processing have allowed the estimation of zenith total delay (ZTD), the delay of the neutral atmosphere, with a high degree of accuracy using continuously operating GPS networks. From this delay integrated water vapor can be derived by means of additional meteorological information, in particular observed pressure or numerical weather prediction model pressure. Comparisons with other independent techniques must be performed to evaluate the quality of atmospheric parameters directly estimated or retrieved from the GPS system. In this work the accuracy of GPS atmospheric parameter, namely, zenith total delay, delivered in near–real time from a European ground-based network of permanent GPS receivers has been assessed. It is compared to other GPS solutions, radiosonde profiles, and High-Resolution Limited-Area Model (HIRLAM)-derived ZTD. Intercomparisons between results from different GPS analysis centers in the framework of the Targeting Optimal Use of GPS Humidity Measurements in Meteorology (TOUGH) project show a mean ZTD station bias at the level of ±6 mm with a related standard deviation of about 7–8 mm. In the comparison with radiosondes, an overall ZTD bias of about 7 mm with a standard deviation of 9 mm is detected. Finally, the comparison of ZTD near–real time against the HIRLAM models has an average bias of about −4.8 mm and a standard deviation of 11.5 mm.

scholarly journals The Zugspitze radiative closure experiment for quantifying water vapor absorption over the terrestrial and solar infrared. Part I: Setup, uncertainty analysis, and assessment of far-infrared water vapor continuum

2016 ◽  
Author(s):  
Ralf Sussmann ◽  
Andreas Reichert ◽  
Markus Rettinger
Keyword(s):  
Remote Sensing ◽  
Water Vapor ◽  
Infrared Spectrum ◽  
Near Infrared ◽  
Far Infrared ◽  
Companion Paper ◽  
Parameter Uncertainties ◽  
Water Vapor Absorption ◽  
Radiative Processes ◽  
Set Up

Abstract. Quantitative knowledge of water vapor radiative processes in the atmosphere throughout the terrestrial and solar infrared spectrum is still incomplete even though this is crucial input to the radiation codes forming the core of both remote sensing methods and climate simulations. Beside laboratory spectroscopy, ground-based remote sensing field studies in terms of so-called radiative closure experiments are a powerful approach, because this is the only way to quantify water absorption under cold atmospheric conditions. For this purpose, we have set up at Mt. Zugspitze (47.42° N, 10.98° E, 2964 m a.s.l.) a long-term radiative closure experiment designed to cover the infrared spectrum between 400 to 7800 cm−1 (1.28–25 µm). As a benefit for such experiments, the atmospheric states at Zugspitze frequently comprise very low integrated water vapor (IWV; minimum = 0.1 mm, median = 2.3 mm) and very low aerosol optical depth (AOD = 0.0024–0.0032 at 7800 cm−1 at airmass 1). All instruments for radiance measurements and atmospheric state measurements are described along with their measurement uncertainties. Based on all parameter uncertainties and the corresponding radiance Jacobians, a systematic residual radiance uncertainty budget has been set up to characterize the sensitivity of the radiative closure over the whole infrared spectral range. The dominant uncertainty contribution in the spectral windows used for far-infrared (FIR) continuum quantification is from IWV uncertainties, while T-profile uncertainties dominate in the mid-infrared (MIR). Uncertainty contributions to near-infrared (NIR) radiance residuals are dominated by water vapor line parameters in the vicinity of the strong water vapor bands. The window regions in between these bands are dominated by solar FTIR calibration uncertainties at low NIR wavenumbers, while uncertainties due to AOD become an increasing and dominant contribution towards higher NIR wavenumbers. Exceptions are methane or nitrous oxide bands in the NIR, where the associated line parameter uncertainties dominate the overall uncertainty. As a first demonstration of the Zugspitze closure experiment, a water vapor continuum quantification in the FIR spectral region (400–580 cm−1) has been performed. The resulting FIR foreign continuum coefficients are consistent with the MT_CKD 2.5.2 continuum model and also agree with the most recent atmospheric closure study carried out in Antarctica. Results from the first determination of the NIR water vapor continuum in a field experiment are detailed in a companion paper (Part III) while a novel NIR calibration scheme for the underlying FTIR measurements of incoming solar radiance is presented in another companion paper (Part II).

scholarly journals How to apply the optimal estimation method to your lidar measurements for improved retrievals of temperature and composition

2018 ◽  
Vol 176 ◽  
pp. 01025
Author(s):  
R. J. Sica ◽  
A. Haefele ◽  
A. Jalali ◽  
S. Gamage ◽  
G. Farhani
Keyword(s):  
Remote Sensing ◽  
Estimation Method ◽  
Optimal Estimation ◽  
Uncertainty Budget ◽  
Ability To Work ◽  
Passive Remote Sensing ◽  
Random Uncertainty ◽  
Lidar Measurements ◽  
History Of ◽  
History Of Use

The optimal estimation method (OEM) has a long history of use in passive remote sensing, but has only recently been applied to active instruments like lidar. The OEM’s advantage over traditional techniques includes obtaining a full systematic and random uncertainty budget plus the ability to work with the raw measurements without first applying instrument corrections. In our meeting presentation we will show you how to use the OEM for temperature and composition retrievals for Rayleigh-scatter, Ramanscatter and DIAL lidars.

scholarly journals Airborne Lidar Observations of Wind, Water Vapor, and Aerosol Profiles During The NASA Aeolus Cal/Val Test Flight Campaign

2020 ◽  
Author(s):  
Kristopher M. Bedka ◽  
Amin R. Nehrir ◽  
Michael Kavaya ◽  
Rory Barton-Grimley ◽  
Mark Beaubien ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Water Vapor ◽  
European Space Agency ◽  
Airborne Lidar ◽  
Horizontal Wind ◽  
Atmospheric Conditions ◽  
Horizontal Wind Speed ◽  
Wide Range ◽  
Test Flight

Abstract. Lidars are uniquely capable of collecting high precision and high spatio-temporal resolution observations that have been used for atmospheric process studies from the ground, aircraft, and space for many years. The Aeolus mission, the first space-borne Doppler wind lidar, was developed by the European Space Agency and launched in August 2018. Its novel Atmospheric LAser Doppler INstrument (ALADIN) observes profiles of the component of the wind vector and aerosol/cloud optical properties along the instrument’s line-of-sight (LOS) direction on a global scale. Two airborne lidar systems have been developed at NASA Langley Research Center in recent years that collect measurements in support of several NASA Earth Science Division focus areas. The coherent Doppler Aerosol WiNd (DAWN) lidar measures vertical profiles of LOS velocity along selected azimuth angles that are combined to derive profiles of horizontal wind speed and direction. The High Altitude Lidar Observatory (HALO) measures high resolution profiles of atmospheric water vapor (WV), and aerosol and cloud optical properties. Because there are limitations in terms of spatial and vertical detail and measurement precision that can be accomplished from space, airborne remote sensing observations like those from DAWN and HALO are required to fill these observational gaps as well as to calibrate and validate space-borne measurements. Over a two-week period in April 2019 during their Aeolus Cal/Val Test Flight campaign, NASA conducted five research flights over the Eastern Pacific Ocean with the DC-8 aircraft. The purpose was to demonstrate: 1) DAWN and HALO measurement capabilities across a range of atmospheric conditions, 2) Aeolus Cal/Val flight strategies and comparisons of DAWN and HALO measurements with Aeolus to gain an initial perspective of Aeolus performance, and 3) how atmospheric dynamic processes can be resolved and better understood through simultaneous observations of wind, WV, and aerosol profile observations, coupled with numerical model and other remote sensing observations. This paper provides a brief description of the DAWN and HALO instruments, discusses the synergistic observations collected across a wide range of atmospheric conditions sampled during the DC-8 flights, and gives a brief summary of the validation of DAWN, HALO, and Aeolus observations and comparisons. 

scholarly journals Airborne lidar observations of wind, water vapor, and aerosol profiles during the NASA Aeolus calibration and validation (Cal/Val) test flight campaign

2021 ◽  
Vol 14 (6) ◽  
pp. 4305-4334
Author(s):  
Kristopher M. Bedka ◽  
Amin R. Nehrir ◽  
Michael Kavaya ◽  
Rory Barton-Grimley ◽  
Mark Beaubien ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Water Vapor ◽  
European Space Agency ◽  
Airborne Lidar ◽  
Horizontal Wind ◽  
Atmospheric Conditions ◽  
Spatiotemporal Resolution ◽  
Wide Range ◽  
Test Flight

Abstract. Lidars are uniquely capable of collecting high-precision and high spatiotemporal resolution observations that have been used for atmospheric process studies from the ground, aircraft, and space for many years. The Aeolus mission, the first space-borne Doppler wind lidar, was developed by the European Space Agency (ESA) and launched in August 2018. Its novel Atmospheric LAser Doppler INstrument (ALADIN) observes profiles of the component of the wind vector and aerosol/cloud optical properties along the instrument's line-of-sight (LOS) direction on a global scale. A total of two airborne lidar systems have been developed at NASA Langley Research Center in recent years that collect measurements in support of several NASA Earth Science Division focus areas. The coherent Doppler Aerosol WiNd (DAWN) lidar measures vertical profiles of LOS velocity along selected azimuth angles that are combined to derive profiles of horizontal wind speed and direction. The High Altitude Lidar Observatory (HALO) measures high resolution profiles of atmospheric water vapor (WV) and aerosol and cloud optical properties. Because there are limitations in terms of spatial and vertical detail and measurement precision that can be accomplished from space, airborne remote sensing observations like those from DAWN and HALO are required to fill these observational gaps and to calibrate and validate space-borne measurements. Over a 2-week period in April 2019, during their Aeolus Cal/Val Test Flight campaign, NASA conducted five research flights over the eastern Pacific Ocean with the DC-8 aircraft. The purpose was to demonstrate the following: (1) DAWN and HALO measurement capabilities across a range of atmospheric conditions, (2) Aeolus Cal/Val flight strategies and comparisons of DAWN and HALO measurements with Aeolus, to gain an initial perspective of Aeolus performance, and (3) ways in which atmospheric dynamic processes can be resolved and better understood through simultaneous observations of wind, WV, and aerosol profile observations, coupled with numerical model and other remote sensing observations. This paper provides a brief description of the DAWN and HALO instruments, discusses the synergistic observations collected across a wide range of atmospheric conditions sampled during the DC-8 flights, and gives a brief summary of the validation of DAWN, HALO, and Aeolus observations and comparisons.

scholarly journals Synergy of Active- and Passive Remote Sensing: An Approach to Reconstruct Three-Dimensional Cloud Macro- and Microphysics

2020 ◽  
Author(s):  
Lucas Höppler ◽  
Felix Gödde ◽  
Manuel Gutleben ◽  
Tobias Kölling ◽  
Bernhard Mayer ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Microwave Radiometer ◽  
Three Dimensional ◽  
Passive Remote Sensing ◽  
Three Dimensional Representation ◽  
Hyper Spectral ◽  
Lidar Measurements ◽  
Research Aircraft ◽  
Remote Sensing Methods ◽  
Thermodynamic Phase

Abstract. This paper presents a method to retrieve three-dimensional cumulus cloud macro- and microphysics measured by remote sensing instruments on the German research aircraft HALO. This is achieved by combining our hyper-spectral pushbroom spectrometer specMACS with active and passive remote sensing instruments, such as a lidar, a microwave radiometer, a radar and dropsondes. Two-dimensional cloud information such as cloud size, optical thickness, effective radius and thermodynamic phase are retrieved by specMACS with established remote sensing methods. Information of the other active and passive remote sensing instruments with a smaller field-of-view are mapped to the wider specMACS swath following Barker et al. (2011). The combination of specMACS with passive and active remote sensing quantities, for example, the Cloud Top Height from lidar measurements, allows new possibilities: three-dimensional cloud macrophysics can be reconstructed. Applying a sub-adiabatic microphysical model constrained with measurements allows to extend the measured quantities to a three-dimensional representation of microphysics. A consistency check by means of a three-dimensional radiative transfer simulation of the specMACS observations of these derived three-dimensional cloud fields shows good agreement.

scholarly journals The Zugspitze radiative closure experiment for quantifying water vapor absorption over the terrestrial and solar infrared – Part 1: Setup, uncertainty analysis, and assessment of far-infrared water vapor continuum

2016 ◽  
Vol 16 (18) ◽  
pp. 11649-11669 ◽  
Author(s):  
Ralf Sussmann ◽  
Andreas Reichert ◽  
Markus Rettinger
Keyword(s):  
Remote Sensing ◽  
Water Vapor ◽  
Infrared Spectrum ◽  
Near Infrared ◽  
Far Infrared ◽  
Companion Paper ◽  
Parameter Uncertainties ◽  
Water Vapor Absorption ◽  
Radiative Processes ◽  
Set Up

Abstract. Quantitative knowledge of water vapor radiative processes in the atmosphere throughout the terrestrial and solar infrared spectrum is still incomplete even though this is crucial input to the radiation codes forming the core of both remote sensing methods and climate simulations. Beside laboratory spectroscopy, ground-based remote sensing field studies in the context of so-called radiative closure experiments are a powerful approach because this is the only way to quantify water absorption under cold atmospheric conditions. For this purpose, we have set up at the Zugspitze (47.42° N, 10.98° E; 2964 m a.s.l.) a long-term radiative closure experiment designed to cover the infrared spectrum between 400 and 7800 cm−1 (1.28–25 µm). As a benefit for such experiments, the atmospheric states at the Zugspitze frequently comprise very low integrated water vapor (IWV; minimum  =  0.1 mm, median  =  2.3 mm) and very low aerosol optical depth (AOD  =  0.0024–0.0032 at 7800 cm−1 at air mass 1). All instruments for radiance measurements and atmospheric-state measurements are described along with their measurement uncertainties. Based on all parameter uncertainties and the corresponding radiance Jacobians, a systematic residual radiance uncertainty budget has been set up to characterize the sensitivity of the radiative closure over the whole infrared spectral range. The dominant uncertainty contribution in the spectral windows used for far-infrared (FIR) continuum quantification is from IWV uncertainties, while T profile uncertainties dominate in the mid-infrared (MIR). Uncertainty contributions to near-infrared (NIR) radiance residuals are dominated by water vapor line parameters in the vicinity of the strong water vapor bands. The window regions in between these bands are dominated by solar Fourier transform infrared (FTIR) calibration uncertainties at low NIR wavenumbers, while uncertainties due to AOD become an increasing and dominant contribution towards higher NIR wavenumbers. Exceptions are methane or nitrous oxide bands in the NIR, where the associated line parameter uncertainties dominate the overall uncertainty. As a first demonstration of the Zugspitze closure experiment, a water vapor continuum quantification in the FIR spectral region (400–580 cm−1) has been performed. The resulting FIR foreign-continuum coefficients are consistent with the MT_CKD 2.5.2 continuum model and also agree with the most recent atmospheric closure study carried out in Antarctica. Results from the first determination of the NIR water vapor continuum in a field experiment are detailed in a companion paper (Reichert and Sussmann, 2016) while a novel NIR calibration scheme for the underlying FTIR measurements of incoming solar radiance is presented in another companion paper (Reichert et al., 2016).

Settlers or Movers? The Temporality of Past Migrations, Political Inaction and its Consequences, 1945–1985

2018 ◽  
Author(s):  
Jozefien De Bock
Keyword(s):  
Temporary Workers ◽  
Guest Workers ◽  
Temporary Migration ◽  
Wide Range ◽  
Settler Societies ◽  
Future Policy ◽  
Set Up ◽  
Legal Frameworks ◽  
Temporary Migrants ◽  
Multicultural Policies

Historically, those societies that have the longest tradition in multicultural policies are settler societies. The question of how to deal with temporary migrants has only recently aroused their interest. In Europe, temporary migration programmes have a much longer history. In the period after WWII, a wide range of legal frameworks were set up to import temporary workers, who came to be known as guest workers. In the end, many of these ‘guests’ settled in Europe permanently. Their presence lay at the basis of European multicultural policies. However, when these policies were drafted, the former mobility of guest workers had been forgotten. This chapter will focus on this mobility of initially temporary workers, comparing the period of economic growth 1945-1974 with the years after the 1974 economic crisis. Further, it will look at the kind of policies that were developed towards guest workers in the era before multiculturalism. This way, it shows how their consideration as temporary residents had far-reaching consequences for the immigrants, their descendants and the receiving societies involved. The chapter will finish by suggesting a number of lessons from the past. If the mobility-gap between guest workers and present-day migrants is not as big as generally assumed, then the consequences of previous neglect should serve as a warning for future policy making.

Active and Passive Remote Sensing Measurements of the Sea Surface Waves

2020 ◽  
Author(s):  
M. Ryabkova ◽  
M. Panfilova ◽  
Yu. Titchenko ◽  
Eu. Meshkov ◽  
V. Karaev ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Waves ◽  
Sea Surface ◽  
Passive Remote Sensing ◽  
Sea Surface Waves
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