The Experts below are selected from a list of 303303 Experts worldwide ranked by ideXlab platform
Kornelia Mies - One of the best experts on this subject based on the ideXlab platform.
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A feasibility study for the retrieval of the total column precipitable water vapour from satellite observations in the blue Spectral Range
Atmospheric Measurement Techniques, 2013Co-Authors: Thomas Wagner, Steffen Beirle, Holger Sihler, Kornelia MiesAbstract:Abstract. We present a new algorithm for satellite retrievals of the atmospheric water vapour column in the blue Spectral Range. The water vapour absorption cross section in the blue Spectral Range is much weaker than in the red Spectral Range. Thus the detection limit and the uncertainty of individual observations are systematically larger than for retrievals at longer wavelengths. Nevertheless, water vapour retrievals in the blue Spectral Range have also several advantages: since the surface albedo in the blue Spectral Range is similar over land and ocean, water vapour retrievals are more consistent than for longer wavelengths. Compared to retrievals at longer wavelengths, the sensitivity for atmospheric layers close to the surface is higher due to the (typically 2 to 3 times) higher ocean albedo in the blue. Water vapour retrievals in the blue Spectral Range are also possible for satellite sensors, which do not measure at longer wavelengths of the visible Spectral Range like the Ozone Monitoring Instrument (OMI). We investigated details of the water vapour retrieval in the blue Spectral Range based on radiative transfer simulations and observations from the Global Ozone Monitoring Experiment 2 (GOME-2) and OMI. It is demonstrated that it is possible to retrieve the atmospheric water vapour column density in the blue Spectral Range over most parts of the globe. The findings of our study are of importance also for future satellite missions (e.g. Sentinel 4 and 5).
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A feasibility study for the retrieval of the total column precipitable water vapor from satellite observations in the blue Spectral Range
2013Co-Authors: Thomas Wagner, Steffen Beirle, Holger Sihler, Kornelia MiesAbstract:Abstract. We present a new algorithm for satellite retrievals of the atmospheric water vapor column in the blue Spectral Range. The water vapor absorption cross section in the blue Spectral Range is much weaker than in the red Spectral Range. Thus the detection limit and the uncertainty of individual observations is systematically larger than for retrievals at longer wavelengths. Nevertheless, water vapor retrievals in the blue Spectral Range have also several advantages: since the surface albedo in the blue Spectral Range is similar over land and ocean, water vapor retrievals are more consistent than for longer wavelengths. Compared to retrievals at longer wavelengths, over ocean the sensitivity for atmospheric layers close to the surface is higher due to the (typically 2 to 3 times) higher ocean albedo in the blue. Water vapor retrievals in the blue Spectral Range are also possible for satellite sensors, which do not measure at longer wavelengths of the visible Spectral Range like the Ozone Monitoring instrument (OMI). We investigated details of the water vapor retrieval in the blue Spectral Range based on radiative transfer simulations and observations from the Global Ozone Monitoring Experiment 2 (GOME-2) and OMI. It is demonstrated that it is possible to retrieve the atmospheric water vapor column density in the blue Spectral Range over most parts of the globe. The findings of our study are of importance also for future satellite missions like e.g. Sentinel 4 and 5.
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A new water vapor retrieval algorithm for satellite observations in the blue Spectral Range
2013Co-Authors: Thomas Wagner, Kornelia Mies, Steffen Beirle, Max PlanckAbstract:Water vapor is involved in many important chemical reactions in the atmosphere and contributes most to the natural greenhouse effect. Its atmospheric abundance is highly variable. Thus observations of the spatio-temporal variation on a global scale are of great importance. Water vapor observations are possible in different Spectral Ranges, e.g. in the microwave, thermal IR or near IR and visible Spectral Range. Satellite measurements in the red Spectral Range have the advantage that they are sensitive for the whole atmospheric column and that they provide global coverage including land and ocean. In this study we present a new algorithm for the retrieval of the global water vapor distribution from satellite observations in the blue Spectral Range. Although the water vapor absorption in this Spectral region is rather weak (about two orders of magnitude smaller than in the red Spectral Range), such retrievals have their advantages: First, because of the weak absorption, no corrections for Spectral saturation effects (like in the red Spectral region) have to be applied. Second, the surface albedo in the blue Spectral region is very similar for land and ocean. Thus such observations have the same sensitivity over both land and ocean. Third, because of the stronger Rayleigh scattering the effects of clouds is smaller than at longer wavelengths. Fourth, the water vapor distribution can be retrieved also from satellite instruments, which do not cover the red Spectral Range (like e.g. OMI or the future Sentinel missions). We show results of the Spectral retrieval in the blue Spectral Range for spectra measured by GOME-2 and OMI. Since GOME-2 also covers the red Spectral region, a direct comparison with the results of the standard water vapor retrieval is possible. We also show corresponding results from radiative transfer simulations. Based on observations and model simulations we characterise the accuracy and the detection limit of the new H2O analysis. We show that it is possible to retrieve the global water vapor distribution in the blue Spectral Range with good accuracy (except parts of the polar regions and high mountains).
Thomas Wagner - One of the best experts on this subject based on the ideXlab platform.
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A feasibility study for the retrieval of the total column precipitable water vapour from satellite observations in the blue Spectral Range
Atmospheric Measurement Techniques, 2013Co-Authors: Thomas Wagner, Steffen Beirle, Holger Sihler, Kornelia MiesAbstract:Abstract. We present a new algorithm for satellite retrievals of the atmospheric water vapour column in the blue Spectral Range. The water vapour absorption cross section in the blue Spectral Range is much weaker than in the red Spectral Range. Thus the detection limit and the uncertainty of individual observations are systematically larger than for retrievals at longer wavelengths. Nevertheless, water vapour retrievals in the blue Spectral Range have also several advantages: since the surface albedo in the blue Spectral Range is similar over land and ocean, water vapour retrievals are more consistent than for longer wavelengths. Compared to retrievals at longer wavelengths, the sensitivity for atmospheric layers close to the surface is higher due to the (typically 2 to 3 times) higher ocean albedo in the blue. Water vapour retrievals in the blue Spectral Range are also possible for satellite sensors, which do not measure at longer wavelengths of the visible Spectral Range like the Ozone Monitoring Instrument (OMI). We investigated details of the water vapour retrieval in the blue Spectral Range based on radiative transfer simulations and observations from the Global Ozone Monitoring Experiment 2 (GOME-2) and OMI. It is demonstrated that it is possible to retrieve the atmospheric water vapour column density in the blue Spectral Range over most parts of the globe. The findings of our study are of importance also for future satellite missions (e.g. Sentinel 4 and 5).
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A feasibility study for the retrieval of the total column precipitable water vapor from satellite observations in the blue Spectral Range
2013Co-Authors: Thomas Wagner, Steffen Beirle, Holger Sihler, Kornelia MiesAbstract:Abstract. We present a new algorithm for satellite retrievals of the atmospheric water vapor column in the blue Spectral Range. The water vapor absorption cross section in the blue Spectral Range is much weaker than in the red Spectral Range. Thus the detection limit and the uncertainty of individual observations is systematically larger than for retrievals at longer wavelengths. Nevertheless, water vapor retrievals in the blue Spectral Range have also several advantages: since the surface albedo in the blue Spectral Range is similar over land and ocean, water vapor retrievals are more consistent than for longer wavelengths. Compared to retrievals at longer wavelengths, over ocean the sensitivity for atmospheric layers close to the surface is higher due to the (typically 2 to 3 times) higher ocean albedo in the blue. Water vapor retrievals in the blue Spectral Range are also possible for satellite sensors, which do not measure at longer wavelengths of the visible Spectral Range like the Ozone Monitoring instrument (OMI). We investigated details of the water vapor retrieval in the blue Spectral Range based on radiative transfer simulations and observations from the Global Ozone Monitoring Experiment 2 (GOME-2) and OMI. It is demonstrated that it is possible to retrieve the atmospheric water vapor column density in the blue Spectral Range over most parts of the globe. The findings of our study are of importance also for future satellite missions like e.g. Sentinel 4 and 5.
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A new water vapor retrieval algorithm for satellite observations in the blue Spectral Range
2013Co-Authors: Thomas Wagner, Kornelia Mies, Steffen Beirle, Max PlanckAbstract:Water vapor is involved in many important chemical reactions in the atmosphere and contributes most to the natural greenhouse effect. Its atmospheric abundance is highly variable. Thus observations of the spatio-temporal variation on a global scale are of great importance. Water vapor observations are possible in different Spectral Ranges, e.g. in the microwave, thermal IR or near IR and visible Spectral Range. Satellite measurements in the red Spectral Range have the advantage that they are sensitive for the whole atmospheric column and that they provide global coverage including land and ocean. In this study we present a new algorithm for the retrieval of the global water vapor distribution from satellite observations in the blue Spectral Range. Although the water vapor absorption in this Spectral region is rather weak (about two orders of magnitude smaller than in the red Spectral Range), such retrievals have their advantages: First, because of the weak absorption, no corrections for Spectral saturation effects (like in the red Spectral region) have to be applied. Second, the surface albedo in the blue Spectral region is very similar for land and ocean. Thus such observations have the same sensitivity over both land and ocean. Third, because of the stronger Rayleigh scattering the effects of clouds is smaller than at longer wavelengths. Fourth, the water vapor distribution can be retrieved also from satellite instruments, which do not cover the red Spectral Range (like e.g. OMI or the future Sentinel missions). We show results of the Spectral retrieval in the blue Spectral Range for spectra measured by GOME-2 and OMI. Since GOME-2 also covers the red Spectral region, a direct comparison with the results of the standard water vapor retrieval is possible. We also show corresponding results from radiative transfer simulations. Based on observations and model simulations we characterise the accuracy and the detection limit of the new H2O analysis. We show that it is possible to retrieve the global water vapor distribution in the blue Spectral Range with good accuracy (except parts of the polar regions and high mountains).
Steffen Beirle - One of the best experts on this subject based on the ideXlab platform.
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A feasibility study for the retrieval of the total column precipitable water vapour from satellite observations in the blue Spectral Range
Atmospheric Measurement Techniques, 2013Co-Authors: Thomas Wagner, Steffen Beirle, Holger Sihler, Kornelia MiesAbstract:Abstract. We present a new algorithm for satellite retrievals of the atmospheric water vapour column in the blue Spectral Range. The water vapour absorption cross section in the blue Spectral Range is much weaker than in the red Spectral Range. Thus the detection limit and the uncertainty of individual observations are systematically larger than for retrievals at longer wavelengths. Nevertheless, water vapour retrievals in the blue Spectral Range have also several advantages: since the surface albedo in the blue Spectral Range is similar over land and ocean, water vapour retrievals are more consistent than for longer wavelengths. Compared to retrievals at longer wavelengths, the sensitivity for atmospheric layers close to the surface is higher due to the (typically 2 to 3 times) higher ocean albedo in the blue. Water vapour retrievals in the blue Spectral Range are also possible for satellite sensors, which do not measure at longer wavelengths of the visible Spectral Range like the Ozone Monitoring Instrument (OMI). We investigated details of the water vapour retrieval in the blue Spectral Range based on radiative transfer simulations and observations from the Global Ozone Monitoring Experiment 2 (GOME-2) and OMI. It is demonstrated that it is possible to retrieve the atmospheric water vapour column density in the blue Spectral Range over most parts of the globe. The findings of our study are of importance also for future satellite missions (e.g. Sentinel 4 and 5).
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A feasibility study for the retrieval of the total column precipitable water vapor from satellite observations in the blue Spectral Range
2013Co-Authors: Thomas Wagner, Steffen Beirle, Holger Sihler, Kornelia MiesAbstract:Abstract. We present a new algorithm for satellite retrievals of the atmospheric water vapor column in the blue Spectral Range. The water vapor absorption cross section in the blue Spectral Range is much weaker than in the red Spectral Range. Thus the detection limit and the uncertainty of individual observations is systematically larger than for retrievals at longer wavelengths. Nevertheless, water vapor retrievals in the blue Spectral Range have also several advantages: since the surface albedo in the blue Spectral Range is similar over land and ocean, water vapor retrievals are more consistent than for longer wavelengths. Compared to retrievals at longer wavelengths, over ocean the sensitivity for atmospheric layers close to the surface is higher due to the (typically 2 to 3 times) higher ocean albedo in the blue. Water vapor retrievals in the blue Spectral Range are also possible for satellite sensors, which do not measure at longer wavelengths of the visible Spectral Range like the Ozone Monitoring instrument (OMI). We investigated details of the water vapor retrieval in the blue Spectral Range based on radiative transfer simulations and observations from the Global Ozone Monitoring Experiment 2 (GOME-2) and OMI. It is demonstrated that it is possible to retrieve the atmospheric water vapor column density in the blue Spectral Range over most parts of the globe. The findings of our study are of importance also for future satellite missions like e.g. Sentinel 4 and 5.
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A new water vapor retrieval algorithm for satellite observations in the blue Spectral Range
2013Co-Authors: Thomas Wagner, Kornelia Mies, Steffen Beirle, Max PlanckAbstract:Water vapor is involved in many important chemical reactions in the atmosphere and contributes most to the natural greenhouse effect. Its atmospheric abundance is highly variable. Thus observations of the spatio-temporal variation on a global scale are of great importance. Water vapor observations are possible in different Spectral Ranges, e.g. in the microwave, thermal IR or near IR and visible Spectral Range. Satellite measurements in the red Spectral Range have the advantage that they are sensitive for the whole atmospheric column and that they provide global coverage including land and ocean. In this study we present a new algorithm for the retrieval of the global water vapor distribution from satellite observations in the blue Spectral Range. Although the water vapor absorption in this Spectral region is rather weak (about two orders of magnitude smaller than in the red Spectral Range), such retrievals have their advantages: First, because of the weak absorption, no corrections for Spectral saturation effects (like in the red Spectral region) have to be applied. Second, the surface albedo in the blue Spectral region is very similar for land and ocean. Thus such observations have the same sensitivity over both land and ocean. Third, because of the stronger Rayleigh scattering the effects of clouds is smaller than at longer wavelengths. Fourth, the water vapor distribution can be retrieved also from satellite instruments, which do not cover the red Spectral Range (like e.g. OMI or the future Sentinel missions). We show results of the Spectral retrieval in the blue Spectral Range for spectra measured by GOME-2 and OMI. Since GOME-2 also covers the red Spectral region, a direct comparison with the results of the standard water vapor retrieval is possible. We also show corresponding results from radiative transfer simulations. Based on observations and model simulations we characterise the accuracy and the detection limit of the new H2O analysis. We show that it is possible to retrieve the global water vapor distribution in the blue Spectral Range with good accuracy (except parts of the polar regions and high mountains).
Roberto R Panepucci - One of the best experts on this subject based on the ideXlab platform.
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tunable silicon microring resonator with wide free Spectral Range
Applied Physics Letters, 2006Co-Authors: Magdalena S. Nawrocka, Xuan Wang, Roberto R PanepucciAbstract:The authors present a silicon-on-insulator single ring resonator with a free Spectral Range equal to 47nm, which is the widest known value for this type of resonators. The ring radius is 2μm and is the smallest ring resonator ever reported, achieving experimentally such a wide Spectral Range. For this ring resonator, the authors demonstrate the quality factor to be equal to 6730±60. They thermally tune the resonant wavelength with 0.11nm∕°C, thus showing the ring resonator as an attractive component for on-chip ultracompact photonic add/drop filters and switches.
R S Windeler - One of the best experts on this subject based on the ideXlab platform.
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super free Spectral Range tunable optical microbubble resonator
Optics Letters, 2010Co-Authors: Michael Sumetsky, Y Dulashko, R S WindelerAbstract:An optical resonator is often called fully tunable if its tunable Range exceeds the Spectral interval that contains the resonances at all the characteristic modes of this resonator. For high-Q-factor spheroidal and toroidal microresonators, this interval coincides with the azimuthal free Spectral Range (FSR). In this Letter, we demonstrate what we believe to be the first mechanically fully tunable spheroidal microresonator created of a silica microbubble having a 100μm order radius and 1μm order wall thickness. The tunable bandwidth of this resonator is more than two times greater than its azimuthal FSR.
