Description: Das Projekt "Model assessment of the solar wind effects on the general circulation of the atmosphere and global ozone distribution" wird vom Umweltbundesamt gefördert und von Physikalisch-Meteorologisches Observatorium Davos und Weltstrahlungszentrum (PMOD,WRC) durchgeführt. This project is aimed to understand and quantify two significant problems: (i) what processes are responsible for the observed solar-climate connections and what is their fractional contribution; (ii) what is the causes of the cold bias in the lower stratosphere and the ozone content overestimation in the extra tropical lower stratosphere obtained by many 3-D climate and photochemical models. In addition to the variable solar UV radiation - that is the focus of a parallel research project - the effects of solar wind energy variations on the temperature and circulation of the middle atmosphere are planned to be studied. These effects are influencing many processes in the ionosphere and magnetosphere. They alternate the configuration of the latter, which in turn changes Earth's electric fields. Several observational studies demonstrated that the lower stratosphere temperature variations tightly correlated with the dynamical pressure of the solar wind and with the position of the magnetopause. The correlation is the most significant in the 20-25 km layer with high heavy ion density due to cosmic rays. The above phenomena are planned to be assessed with a General Circulation Model with interactive Photo-Chemistry (GCM/PC) with inclusion of additional heating in this layer caused by electrical resistance of the additional electrical current induced by the solar wind and magnetopause variations. We propose to carry out several 15-20 year long runs of the GCM/PC model with interactive photochemistry described and validated in (Rozanov et al., 2001). The above-mentioned additional heating rate will be introduced in the model using a newly developed parameterisation. The comparison of the control run for unperturbed conditions (solar activity minimum) and of solar maximum perturbed conditions with and without the newly introduced parameterisation will allow to estimate the significance of the new source of external energy for the simulating the present day climate and to assess the strength of the relations between the solar wind variance and stratosphere and to estimate their statistical significance. The magnitude of the solar wind effect will be compared with changes in the climate system caused by the UV solar flux variability to estimate which process is more significant. The results of the numerical experiments will be also compared to the results of the observation data analysis. The proposed research potentially could fill two gaps in our knowledge. It will introduce a new process which could be partially responsible for the observed sun-climate relations and could give a new explanation for the cold bias in the lower stratosphere simulated by the majority of GCMs. If the new mechanism is found to be significant it will help to understand the nature of solar-climate connections and to estimate with better accuracy what part of the climate changes can be related to the solar variability.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Rochen ? Ozon ? Ozonwert ? Photochemischer Smog ? Nichtionisches Tensid ? Davos ? Photochemie ? Solarenergie ? Solarstrahlung ? Windenergie ? Wind ? UV-Strahlung ? Globales Klimamodell ? Licht ? Modellierung ? Klimamodell ? Solarheizung ? Stratosphäre ? Studie ? Ionen ? Zirkulationsmodell ? Ozonschicht ? Ionosphäre ? Photochemische Reaktion ? Ozonbildung ? Mittlere Atmosphäre ? Forschungsprojekt ? Atmosphäre ? Heizung ? Wetter ? Klimawandel ? Fotografie ? Klimasystem ? meteorologischer faktor ? Elektrisches Feld ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2002-05-01 - 2005-04-30
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