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Showing 1 to 20 of 32 for “"Optical absorption spectroscopy"”.
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Derivation of Trace Gas Information combining Differential Optical Absorption Spectroscopy with Radiative Transfer Modelling
The Differential Optical Absorption Spectroscopy (DOAS) is an established remote sensing technique for atmospheric constituent probing. To derive quantitative distribution data of trace gas distributions it is necessary to combine novel measurement techniques like Multi-Axis DOAS with realistic …
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RARE-EARTH AND ALKALINE-EARTH HALIDES WITH SCINTILLATION ACTIVATORS AND CO-DOPANTS STUDIED BY PICOSECOND OPTICAL ABSORPTION SPECTROSCOPY
… excited populations is studied with picosecond spectroscopy of optical absorption induced by interband excitation.
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Field Measurements of Water Continuum and Water Dimer Absorption by Active Long Path Differential Optical Absorption Spectroscopy (DOAS)
… radiation. Superimposed on the water monomer absorption, a water continuum absorption has long been recognized, but its true nature still remains controversial. On the one hand, this absorption is explained by a deformation of the line shape of the water monomer absorption lines as a …
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Halogen Oxide Studies in the Boundary Layer by Multi Axis Differential Optical Absorption Spectroscopy and Active Longpath-DOAS
The importance of reactive halogen species (particularly halogen oxides) in the troposphere is due to their strong effect on tropospheric ozone levels, which has been first discovered during surface ozone depletion episodes in the polar boundary layer after polar sunrise (bromine oxide, BrO). …
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Determining Emission Factors from Marine Vessels Employing Differential Optical Absorption Spectroscopy (DOAS) and Tunable Diode Laser Absorption Spectroscopy (TDLAS)
High SO2 concentrations are harmful to human health and impact climate by affecting cloud formation. Ship contrails are the major source of SO2 in the open-ocean and impact coastal region air quality. The International Maritime Organization (IMO) regulates SO2 emissions by requiring ships to use …
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A General Observational Strategy for Validation of Satellite NO₂ Retrievals using Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS)
… of spatially averaged Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements at regular azimuth angle intervals on an hourly basis to validate satellite based DOAS measurements. Off-Axis MAX-DOAS Measurements taken in Blacksburg, Virginia, between November 2021 and …
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Retrieval of trace gases vertical profile in the lower atmosphere combining. Differential Optical Absorption Spectroscopy with radiative transfer models
… used, referred to as Multiple AXis Differential Optical Absorption Spectroscopy (MAX-DOAS), is a recent technique that represents a significant advance on the well-established DOAS, especially for what it concerns the study of tropospheric trace consituents. NO2 is an important trace gas in the …
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Studies of Reactive Halogen Species (RHS) in the Marine and mid-Latitudinal Boundary Layer by Active Longpath Differential Optical Absorption Spectroscopy
Untersuchungen von Reaktiven Halogenverbindungen (RHS) in der Maritimen Grenzschicht und in Mittleren Breiten mit der Aktiven Langpfad DOAS Methode Die Relevanz reaktiver Halogenverbindungen in der Troposphare ist einerseits belegt durch den gravierenden Ein uss auf Ozon, welcher zum ersten Mal …
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The Measurement of Atmospheric Species with Absorptions Close to the Actinic Flux Cut-Off by Active & MAX-DOAS: Chlorine Monoxide (CIO) & Sulphur Dioxide (SO2)
… of salt water, using techniques of differential optical absorption spectroscopy (DOAS). In particular, we seek to determine whether this trace gas is present in any appreciable amount in ambient air during the wintertime owing to the widespread application of road salt. The study was performed at …
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Electronic Coupling Effects and Charge Transfer between Organic Molecules and Metal Surfaces
We employ a variant of optical absorption spectroscopy, namely in situ differential reflectance spectroscopy (DRS), for an analysis of the structure-properties relations of thin epitaxial organic films. Clear correlations between the spectra and the differently intense coupling to the respective …
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Remote Sensing of the Lower Atmosphere: From Surface Concentration to Mixing Layer Height
Differential Optical Absorption Spectroscopy (DOAS) is a remote sensing technique to detect different trace gas concentrations in the atmosphere. The Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements by the Pandora instrument scan the sky at different elevation angles …
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Zur Halogenaktivierung im Aerosol und in Salzpfannen
… Heidelberg ein Langpfad-DOAS (Differential Optical Absorption Spectroscopy) installiert. In diesem Aufbau wurden zwei Arten von Experimenten durchgeführt: mit künstlichem Meerwasseraerosol und mit Salzpfannen. Nachgewiesen wurde ein starker Einfluss der Stickoxide auf die Aktivierung der …
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Retrieval Advances of BrO/SO2 Molar Ratios from NOVAC
… the recorded spectra by applying Differential Optical Absorption Spectroscopy(DOAS) and comparing the optical absorption of the volcanic plume to the background. Therefore, the background spectrum must not be affected by volcanic influence. Classically, the background spectrum is taken from the …
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Development and Application of a Versatile Balloon-Borne DOAS Spectrometer for Skylight Radiance and Atmospheric Trace Gas Profile Measurements
… the line of sight by applying the Differential Optical Absorption Spectroscopy (DOAS) method. Radiative Transfer (RT) calculations are used to (a) simulate the measured quantities and (b) infer vertical profiles of O3, NO2, and BrO concentrations. Since the measurements were performed under a …
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Studies of the Stratospheric Nitrogen and Iodine Chemistry by Balloon-Borne DOAS Measurements and Model Calculations
… reports and discusses balloon-borne Differential Optical Absorption Spectroscopy (DOAS) measurements of stratospheric trace gas profiles. The focus of this study was to measure the vertical distribution of O3, NO2, IO, and OIO during different geophysical conditions. In combination with the …
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Vertical Profiles of NO 2 and HONO in the Planetary Boundary Layer
… a commercial active Long Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument has been advanced to fully operational status and its optical and mechanical parameters were characterised. This system was used for long-term measurements (13 months) of vertical profiles of NO2 …
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Investigation of Inorganic Stratospheric Bromine using Balloon-Borne DOAS Measurements and Model Simulations
… stratospheric balloon-borne DOAS (Differential Optical Absorption Spectroscopy) measurements of bromine-monoxide (BrO) were analysed and interpreted using the 3-D CTM (Chemical Transport Model) SLIMCAT [Chipperfield98] and a 1-D photochemical model. Photochemical changes were calculated along …
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Quantifying Stratospheric Chlorine Chemistry by the Satellite Spectrometers GOME and SCIAMACHY
… the biosphere are considerable. By differential optical absorption spectroscopy (DOAS) various molecules with characteristic absorption spectra can be detected simultaneously in the atmosphere, among them also many halogen compounds. In this thesis, measurements of the satellite spectrometers …
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Spectroscopic measurements of atmospheric trace gases at Neumayer-Station, Antarctica
… presents a two years record of Differential Optical Absorption Spectroscopy (DOAS) observations of zenith scattered sunlight at the German Antarctic research station Neumayer (70°S, 8°W). The measurements of the atmospheric trace gases ozone, NO2, OClO, BrO, IO and O4 were performed using a …
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Investigation of the stratospheric inorganic Bromine budget for 1996 - 2000 : balloon-borne measurements and model comparisons
… in detail stratospheric DOAS (Differential Optical Absorption Spectroscopy) BrO vertical profile measurements with direct sunlight, that were conducted aboard the french-german LPMA/DOAS (Laboratoire de Physique Moléculaire et Application) balloon gondola at mid and high northern latitudes …
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