Global ETD Search

31	Variability of Gravity Wave Effects on the Zonal Mean Circulation and Migrating Terdiurnal Tide as Studied With the Middle and Upper Atmosphere Model (MUAM2019) Using a Nonlinear Gravity Wave Scheme Lilienthal, Friederike, Yig˘ it, Erdal, Samtleben, Nadja, Jacobi, Christoph 03 April 2023 (has links) Implementing a nonlinear gravity wave (GW) parameterization into a mechanistic middle and upper atmosphere model, which extends to the lower thermosphere (160 km), we study the response of the atmosphere in terms of the circulation patterns, temperature distribution, and migrating terdiurnal solar tide activity to the upward propagating smallscale internal GWs originating in the lower atmosphere. We perform three test simulations for the Northern Hemisphere winter conditions in order to assess the effects of variations in the initial GWspectrum on the climatology and tidal patterns of the mesosphere and lower thermosphere. We find that the overall strength of the source level momentum flux has a relatively small impact on the zonal mean climatology. The tails of the GW source level spectrum, however, are crucial for the lower thermosphere climatology. With respect to the terdiurnal tide, we find a strong dependence of tidal amplitude on the induced GW drag, generally being larger when GW drag is increased. info:eu-repo/classification/ddc/520 ddc:520
32	Variability of Gravity Wave Effects on the Zonal Mean Circulation and Migrating Terdiurnal Tide as Studied With the Middle and Upper Atmosphere Model (MUAM2019) Using a Nonlinear Gravity Wave Scheme Lilienthal, Friederike, Yiğit, Erdal, Samtleben, Nadja, Jacobi, Christoph 21 March 2023 (has links) Implementing a nonlinear gravity wave (GW) parameterization into a mechanistic middle and upper atmosphere model, which extends to the lower thermosphere (160 km), we study the response of the atmosphere in terms of the circulation patterns, temperature distribution, and migrating terdiurnal solar tide activity to the upward propagating small scale internal GWs originating in the lower atmosphere. We perform three test simulations for the Northern Hemisphere winter conditions in order to assess the effects of variations in the initial GW spectrum on the climatology and tidal patterns of the mesosphere and lower thermosphere. We find that the overall strength of the source level momentum flux has a relatively small impact on the zonal mean climatology. The tails of the GW source level spectrum, however, are crucial for the lower thermosphere climatology. With respect to the terdiurnal tide, we find a strong dependence of tidal amplitude on the induced GW drag, generally being larger when GW drag is increased. info:eu-repo/classification/ddc/520 ddc:520
33	Progress in space weather modeling in an operational environment Tsagouri, I., Belehaki, A., Bergeot, N., Cid, C., Delouille, V., Egorova, T., Jakowski, N., Kutiev, I., Mikhailov, A., Nunez, M., Pietrella, M., Potapov, A., Qahwaji, Rami S.R., Tulunay, Y., Velinov, P., Viljanen, A. January 2013 (has links) Yes / This paper aims at providing an overview of latest advances in space weather modeling in an operational environment in Europe, including both the introduction of new models and improvements to existing codes and algorithms that address the broad range of space weather's prediction requirements from the Sun to the Earth. For each case, we consider the model's input data, the output parameters, products or services, its operational status, and whether it is supported by validation results, in order to build a solid basis for future developments. This work is the output of the Sub Group 1.3 "Improvement of operational models'' of the European Cooperation in Science and Technology (COST) Action ES0803 "Developing Space Weather Products and services in Europe'' and therefore this review focuses on the progress achieved by European research teams involved in the action. Space weather ; Modelling ; Forecasting ; Services ; Space environment ; Characteristic energy intervals ; Ionospheric regional model ; Topside sounders model ; Solar-wind parameters ; Electron-density ; Middle atmosphere ; Scale height ; Geomagnetic-pulsations ; European area ; Rate profiles

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