Quarterly Journal of the Royal Meteorological Society, 2014
We examine the linearity of the Ensemble of Data Assimilations (EDA) technique with respect to th... more We examine the linearity of the Ensemble of Data Assimilations (EDA) technique with respect to the amplitude of the applied observation perturbations. We provide explicit examples to assess the linear relationship between such modifications of the observing system and the resulting changes in the EDA ensemble spread. The results demonstrate that, for a state‐of‐the‐art numerical weather prediction (NWP) system, such linearity between the applied observation perturbations and the EDA ensemble spread holds well for temporal and spatial regimes relevant to global medium‐range weather prediction: specifically, for forecast lead‐times of up to approximately 5 days, in the vertical throughout the troposphere up to the lower and middle stratosphere and for broad horizontal scales.
<p>Global three-dimensional data are a key to understanding gravity waves in the me... more <p>Global three-dimensional data are a key to understanding gravity waves in the mesosphere and lower thermosphere. MATS is a small Swedish satellite that aims at providing such fields using tomographic measurements of oxygen A-band airglow and noctilucent clouds. MATS was successfully launched from Mahia, New Zealand, on November 4, 2022. Data collection started in December 2022, and MATS is projected to have collected over 3 million images of the MLT region by April 2023.</p> <p>This presentation will provide an overview over first results from the MATS data. This includes analysis of in-flight performance of the instruments, an overview of data availability, and some examples of possible usage of the data. We will discuss data quality as well as possible biases and uncertainties that need to be considered when using this new and unique dataset for mesospheric studies.</p>
The mesospheric polar vortex (MPV) plays a critical role in coupling the atmosphere-ionosphere sy... more The mesospheric polar vortex (MPV) plays a critical role in coupling the atmosphere-ionosphere system, so its accurate simulation is imperative for robust predictions of the thermosphere and ionosphere. While the stratospheric polar vortex is widely understood and characterized, the mesospheric polar vortex is much less well-known and observed, a short-coming that must be addressed to improve predictability of the ionosphere. The winter MPV facilitates top-down coupling via the communication of high energy particle precipitation effects from the thermosphere down to the stratosphere, though the details of this mechanism are poorly understood. Coupling from the bottom-up involves gravity waves (GWs), planetary waves (PWs), and tidal interactions that are distinctly different and important during weak vs. strong vortex states, and yet remain poorly understood as well. Moreover, generation and modulation of GWs by the large wind shears at the vortex edge contribute to the generation of...
In the course of the European ECOMA project (ECOMA = Existence and Charge State of Meteoric Smoke... more In the course of the European ECOMA project (ECOMA = Existence and Charge State of Meteoric Smoke Particles in the Middle Atmosphere) two sounding rocket campaigns were conducted in September 2006 and August 2007 from the North Norwegian Andoya Rocket Range (69N). The latter campaign was closely coordinated with the US-American MASS campaign which also focused on mesospheric aerosol particles and their plasma environment. A core instrument of the ECOMA payload is a Faraday-Cup-based particle detector which is combined with a Xenon-flashlight for the active photo-ionization of mesospheric aerosol particles. The first launch in September 2006 revealed evidence for meteor smoke particles in the entire altitude range from 60 - 110 km, as indicated by detected photo-emission signatures. In August 2007, however, when the ECOMA payload was launched into a weak event of polar mesosphere summer echoes and noctilucent clouds, particle signatures were confined to the altitude region of mesosph...
Quarterly Journal of the Royal Meteorological Society, 2014
We examine the linearity of the Ensemble of Data Assimilations (EDA) technique with respect to th... more We examine the linearity of the Ensemble of Data Assimilations (EDA) technique with respect to the amplitude of the applied observation perturbations. We provide explicit examples to assess the linear relationship between such modifications of the observing system and the resulting changes in the EDA ensemble spread. The results demonstrate that, for a state‐of‐the‐art numerical weather prediction (NWP) system, such linearity between the applied observation perturbations and the EDA ensemble spread holds well for temporal and spatial regimes relevant to global medium‐range weather prediction: specifically, for forecast lead‐times of up to approximately 5 days, in the vertical throughout the troposphere up to the lower and middle stratosphere and for broad horizontal scales.
<p>Global three-dimensional data are a key to understanding gravity waves in the me... more <p>Global three-dimensional data are a key to understanding gravity waves in the mesosphere and lower thermosphere. MATS is a small Swedish satellite that aims at providing such fields using tomographic measurements of oxygen A-band airglow and noctilucent clouds. MATS was successfully launched from Mahia, New Zealand, on November 4, 2022. Data collection started in December 2022, and MATS is projected to have collected over 3 million images of the MLT region by April 2023.</p> <p>This presentation will provide an overview over first results from the MATS data. This includes analysis of in-flight performance of the instruments, an overview of data availability, and some examples of possible usage of the data. We will discuss data quality as well as possible biases and uncertainties that need to be considered when using this new and unique dataset for mesospheric studies.</p>
The mesospheric polar vortex (MPV) plays a critical role in coupling the atmosphere-ionosphere sy... more The mesospheric polar vortex (MPV) plays a critical role in coupling the atmosphere-ionosphere system, so its accurate simulation is imperative for robust predictions of the thermosphere and ionosphere. While the stratospheric polar vortex is widely understood and characterized, the mesospheric polar vortex is much less well-known and observed, a short-coming that must be addressed to improve predictability of the ionosphere. The winter MPV facilitates top-down coupling via the communication of high energy particle precipitation effects from the thermosphere down to the stratosphere, though the details of this mechanism are poorly understood. Coupling from the bottom-up involves gravity waves (GWs), planetary waves (PWs), and tidal interactions that are distinctly different and important during weak vs. strong vortex states, and yet remain poorly understood as well. Moreover, generation and modulation of GWs by the large wind shears at the vortex edge contribute to the generation of...
In the course of the European ECOMA project (ECOMA = Existence and Charge State of Meteoric Smoke... more In the course of the European ECOMA project (ECOMA = Existence and Charge State of Meteoric Smoke Particles in the Middle Atmosphere) two sounding rocket campaigns were conducted in September 2006 and August 2007 from the North Norwegian Andoya Rocket Range (69N). The latter campaign was closely coordinated with the US-American MASS campaign which also focused on mesospheric aerosol particles and their plasma environment. A core instrument of the ECOMA payload is a Faraday-Cup-based particle detector which is combined with a Xenon-flashlight for the active photo-ionization of mesospheric aerosol particles. The first launch in September 2006 revealed evidence for meteor smoke particles in the entire altitude range from 60 - 110 km, as indicated by detected photo-emission signatures. In August 2007, however, when the ECOMA payload was launched into a weak event of polar mesosphere summer echoes and noctilucent clouds, particle signatures were confined to the altitude region of mesosph...
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