Weber, Mark
Lade...
Preferred name
Weber, Mark
Official Name
Weber, Mark
Email
weber@uni-bremen.de
ORCID
GND
7 Ergebnisse
Gerade angezeigt 1 - 7 von 7
- Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, WF-DOAS V1.0 Validation ReportThis report summarizes the validation of the GOME total ozone derived from applying the weighting function DOAS (WF-DOAS) algorithm Version 1.0. This algorithm was developed as part of the GOTOCORD ESA project (see accompanying ATBD Report). The WF-DOAS results have been compared with selected ground-based measurements from the WOUDC (World Ozone and UV Radiation Data Centre) which collects total zone measurements from a global network of stations. Very few of these stations carry out simultaneous measurements by Brewer and Dobson spectrometers over an extended period (three years or more). Simultaneous Brewer and Dobson measurements from Hradec Kralove, Czech Republic (50.2◦N, 15.8◦E) and Hohenpeissenberg, Germany (47.8◦N, 11.0◦E) covering the period 1996-1999 have been compared with our GOME results and particular attention is paid to the differences between the two ground spectrometer types and GOME.BerichtHeft:Issue 1.2245 110 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Solar activity during solar cycle 23 monitored by GOMEThe daily solar spectral measurements by the Global Ozone Monitoring Experiment (GOME) aboard ERS2 are well suited to track solar activity by looking at irra- diance changes in the center of selected Fraunhofer lines. The major modulation of the irradiance changes con- tain periodicity of about 27-28 days, corresponding to the mean solar rotation period, and eleven years due to solar activity associated with the 22-year magnetic cycle of the sun. The MgII doublet at 280nm and the CaII K line at around 395nm have been analysed to derive a proxy so- lar activity indicator time series from GOME starting in July 1995 near the end of the declining phase of solar cycle 22. GOME is currently observing the onset of solar cycle 23. An excellent correlation with solar observations provided by the UARS instrument SUSIM (Solar Ultravi- olet Spectral Irradiance Monitor) has been achieved after removing instrumental artefacts such as UV degradation and etaloning from the GOME level-1 spectra. An esti- mate of solar UV irradiance variability with a change in the GOME MgII index is given.KonferenzbeitragBand:161198 88 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, User requirements for monitoring the evolution of stratospheric ozone at high vertical resolution (‘Operoz’: Operational ozone observations using limb geometry)(2015-03-01); ; ; ; The purpose of the Operoz study has been threefold: (i) To establish the user requirements for an operational mission targeting ozone profiles at high vertical resolution, (ii) To identify the observational gaps with respect to these user requirements taking into account planned operational missions and observational ground networks, and (iii) To perform a reality check on the observational requirements based on proven concepts and present-day knowledge of potentially available measurement techniques and to identify options for a small to medium size satellite mission.Buch231 120 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, WFDOAS V1.0 Delta-Validation Report(2004-01); ; This document serves two purposes, first, it contains a reply to the comments made by the Panel Review (see PANEL–REVIEW) and secondly it summarizes the results from the Delta Validation that was carried out after the review. The comments made by the review were fair and well balanced and the reviewers are thanked for their thoughtful suggestions. It is also agreed that all three consortia using different algorithm concepts have significantly improved total ozone retrieval as compared to the current GOME data processor version 3.0. On first sight it appears that the overall performance of all algorithms (TOGOMI, GODFIT, and WFDOAS) have produced consistent and similar results such that it was indeed hard for the review board to decide which of the algorithm is the most appropriate to succeed Version 3. Since GODFIT uses online radiative transfer calculations its processing speed is about a factor of five slower than compared to TOGOMI and WFDOAS. It was therefore decided to inter-compare TOGOMI and WFDOAS with GDOAS, a standard DOAS retrieval, that has been used by BIRA to assess the GDP V3 data quality. GDOAS closely resembles the GOME Data Processor as described in Section 6.1 in GODFIT–VALREPORT. Major differences to GDP V3 are the inclusion of the ozone filling-in like in WFDOAS, TOGOMI, and GODFIT and the use of an updated surface albedo climatology using the minimum Lambertian equivalent reflectivity database from Koelemijer et al. (2002).BerichtHeft:Issue 1.0192 112 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, SCIAMACHY V8 Solar Spectral Irradiance Validation(2017-11-27); ; ; SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) on-board the ESA Envisat satellite platform provided daily solar spectra in the wavelength region from 0.24 μm to 2.4 μm. The instrument was operating for nearly a decade from August 2002 to April 2012. This document reports on the validation of the SCIAMACHY solar spectral irradiances (SSI) in its data version 8. Like other UV satellite sounders, the SCIAMACHY spectrometer suffers from optical degradation due to polymerisation of optical surfaces from the harsh UV radiation in space (e.g. Bramstedt et al., 2009; DeLand et al., 2012; Krijger et al., 2014). In data version 8 of SCIAMACHY a physical model of the scanner unit was implemented to provide a degradation correction (Bramstedt et al., 2009; Krijger et al., 2014). Comparisons with several other established solar reference spectra show agreement to within 4 % in most parts of the visible and near infrared from 350 to 1400 nm.Bericht253 218 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, WF-DOAS Algorithm Theoretical Basis DocumentA novel total ozone retrieval algorithm that we call weighting function DOAS has been successfully implemented as an alternative approach to the standard DOAS differential optical absorption spectroscopy) that is currently operational in the GOME retrieval Gome Data Processor Version 3.0). The weighting function DOAS method, abbreviated WF-DOAS, attempts to fit the vertical column density directly from the differential optical depth spectra and it can be applied to strong and weak absorption. This method has been demonstrated to be applicable to near-infrared trace gas column retrieval with CIAMACHY and it has been adapted for total ozone retrieval in the near UV region. The processing of the GOME data is done in a non-linear least squares fitting using look-up-tables of reference intensities, weighting functions, and Ring spectra derived from the multiple scattering radiative transfer model SCIATRAN/CDI. Particular attention has been placed on proper modeling of the Ring effect that show significant dependence on the ozone profile shape due to molecular (ozone) filling-in. Other geophysical parameters such as effective albedo, cloud-top-height, cloud fraction, and effective height that are retrieved from GOME spectral information are used for the first time in combination to improve the ozone retrieval.BerichtHeft:Issue 1.2225 111 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Impact of ozone cross-section choice on WFDOAS total ozone retrieval applied to GOME, SCIAMACHY, and GOME-2 (1995-present)(2013-11-01); ; ; ; Technical Note Issue 2 (January 2011) with updates from November 2013. A contribution to ACSO http://igaco-o3.fmi.fi/ACSO/. In this technical note we investigate how the choice of ozone cross-sections impact the WFDOAS (Weighting Function Differential Optical Absorption Spectroscopy) total ozone retrieval (Coldewey-Egbers et al., 2005) for the satellite instruments GOME, GOME-2, and SCIAMACHY.Bericht250 117