Globale Karten des totalen Elektronengehaltes (TEC) der Ionosphäre werden nach Signalen planetarer Wellenaktivität aus der Stratosphäre im Bereich der mittleren Breiten (ca. 52.5° N) untersucht, um eine Abschätzung über die vertikale Kopplung durch planetare Wellen (PW) zu erhalten. Die Variabilität der Ionosphäre wird operationell durch das DLR Neustrelitz erfasst. Seit 2002 werden zu diesem Zwecke hemisphärische TEC Karten erstellt, die eine Analyse PW typischer Oszillationen in der Ionosphäre ermöglichen. Die verwendete Methode zur Analyse separiert Wellen nach ihrer zonalen Wellenzahl, Periode und Ausbreitungsrichtung. In einer vorherigen Fallstudie vom Herbst 2004 wurde u.a. die quasi 6-Tage Welle (m2w) im mittleren Spektrum für das Geopotential in 1hPa (Stratosphäre) als auch den ionosphärischen TEC beobachtet. Die aktuellen Resultate geben Hinweise für ein gleichzeitiges Auftreten dieserWelle mit einer quasi 6-Tage Oszillation in der Mesopausenregion. Jedoch im Vergleich zur Stratosphäre scheinen die Signaturen verschoben und etwas modifiziert. / The response of stratospheric planetary wave (PW) activity over the higher middle latitudes (ca. 52.5° N) in global gridded ionospheric data of the total electron content (TEC) are investigated to estimate the vertical coupling by PW. The monitoring of ionospheric variability is regularly operated by DLR Neustrelitz since 2002 producing TEC maps covering the northern hemisphere. This data base is considered for comparing simultaneous observations of wave activity in both stratosphere and ionosphere. The analysis technique of planetary wave type oscillations (PWTO) is carried out by separating waves into their zonal wavenumber, period and travelling direction. A previous case study of autumn 2004 has shown that among other things the quasi 6-day wave (m2w) is visible in the mean spectrum of stratospheric geopotential height at 1 hPa pressure level and of ionospheric TEC data. The actual results give hints for a simultaneous occurrence of this wave type with a quasi 6-day oscillation in the mesopause region. But in comparison to the stratosphere, the wave signatures seem to be somewhat schifted and modified.

Die Anregung von planetarer Wellenaktivität in der Südwinter Stratosphäre wird anhand von Beobachtungsdaten untersucht. Die statistischen Untersuchungen zeigen, dass dem nichtlinearen Antrieb, erzeugt durch Wechselwirkungen zwischen den transienten baroklinen Eddies, eine entscheidende Rolle zu kommt. Aus täglichen Stromfunktionsfeldern der Südhemisphäre ist dazu die Berechnung des nichtlinearen tiefpass gefilterten Antriebes für Wellen mit zonalen Wellenzahlen eins und zwei erfolgt. Eine CEOF Analyse mit anschliessender MSSA liefert dominante Strukturen, die die Wechselwirkungen zwischen Tropo- und Stratosphäre sehr gut beschreiben. Die aus der MSSA abgeleiteten vertikalen Ausbreitungszeiten stimmen mit denen aus der Literatur bekannten überein. / Using observational data the forcing of planetary wave variability in the southern winter hemisphere is examined. The statistical analyses point out clearly the important role of the nonlinear eddy forcing. We calculate the low pass filtered nonlinear eddy forcing for waves with wavenumbers one and two from daily streamfunction fields. Our approach combines a complex empirical function analysis with a multichannel singular spectrum analysis. The resulting eigenstructures can be used to explain the interaction between the Troposphere and Stratosphere. We compare the dominant vertical propagation time scales obtained from our analysis with results existing in literature and find good agreement.

Die nichtlineare Wechselwirkung der Quasi Zwei-Tage-Welle (QZTW) mit anderen planetaren Wellen führt zu wesentlichen Amplitudenmodulationen der Zwei-Tage Welle und zu einer Reihe auftretender sekundärer Wellen. die Ergebnisse der verschiedenen Experimte zur Wechselwirkung der Quasi Zwei-Tage Welle mit jeweils der 10-Tage Welle, der 16-Tage Welle und der 5-Tage Welle zeigen, dass die Amplitude der QZTW unter der Wechselwirkung mit der der 16-Tage Welle und der 10-Tage Welle um bis zu 20 % reduziert wird. Die stationäre planetare Welle mit der zonalen Wellenzahl 1 (SPW1) scheint die wichtigste Rolle bei den nichtlinearen Wechselwirkungen mit der QZTW zu spielen, da die daraus entstehenden sekundären Wellen mit den Wellenzahlen 2 und 4 dieselbe Periode wie die QZTW haben. Die Überlagerung der Quasi Zwei-Tage Welle und ihrer sekundären Wellen verstärkt die Amplitude um bis zu 60 %. / The non-linear interaction of the quasi two-day wave (QTDW) with other planetary waves leads to remarkable amplitude modulations of the QTDW and to arising secondary waves. Results of several numerical experiments considering the behaviour of the QTDW in connection with the 16-, 10-, and 5-day wave have shown that the amplitude of the QTDW reduces under interaction with the 16DW and 10DW. The stationary planetary wave with zonal wave number 1 (SPW1) seems to play the most important role, because resulting secondary waves exhibit the same period as the QTDW. The superposition of these waves leads to an enhancement of the QTDW-amplitude up to 60 %. This means, that a strong amplification of the QTDW measured by RADAR instruments can be due to interaction between the QTDW and a strong SPW1.

Globale Karten des totalen Elektronengehaltes (TEC) der Ionosphäre werden nach Signalen planetarer Wellenaktivität aus der Stratosphäre im Bereich der mittleren Breiten (ca. 52.5° N) untersucht, um eine Abschätzung über die vertikale Kopplung durch planetare Wellen (PW) zu erhalten. Die Variabilität der Ionosphäre wird operationell durch das DLR Neustrelitz erfasst. Seit 2002 werden zu diesem Zwecke hemisphärische TEC Karten erstellt, die eine Analyse PW typischer Oszillationen in der Ionosphäre ermöglichen. Die verwendete Methode zur Analyse separiert Wellen nach ihrer zonalen Wellenzahl, Periode und Ausbreitungsrichtung. In einer vorherigen Fallstudie vom Herbst 2004 wurde u.a. die quasi 6-Tage Welle (m2w) im mittleren Spektrum für das Geopotential in 1hPa (Stratosphäre) als auch den ionosphärischen TEC beobachtet. Die aktuellen Resultate geben Hinweise für ein gleichzeitiges Auftreten dieserWelle mit einer quasi 6-Tage Oszillation in der Mesopausenregion. Jedoch im Vergleich zur Stratosphäre scheinen die Signaturen verschoben und etwas modifiziert. / The response of stratospheric planetary wave (PW) activity over the higher middle latitudes (ca. 52.5° N) in global gridded ionospheric data of the total electron content (TEC) are investigated to estimate the vertical coupling by PW. The monitoring of ionospheric variability is regularly operated by DLR Neustrelitz since 2002 producing TEC maps covering the northern hemisphere. This data base is considered for comparing simultaneous observations of wave activity in both stratosphere and ionosphere. The analysis technique of planetary wave type oscillations (PWTO) is carried out by separating waves into their zonal wavenumber, period and travelling direction. A previous case study of autumn 2004 has shown that among other things the quasi 6-day wave (m2w) is visible in the mean spectrum of stratospheric geopotential height at 1 hPa pressure level and of ionospheric TEC data. The actual results give hints for a simultaneous occurrence of this wave type with a quasi 6-day oscillation in the mesopause region. But in comparison to the stratosphere, the wave signatures seem to be somewhat schifted and modified.

Atmospheric planetary waves play a role in introducing variability to the low-latitude ionosphere. To better understand this coupling, this study investigates times when oscillations seen in both atmospheric planetary waves and ionospheric data-sets have similar periodicity. The planetary wave data-set used are temperature observations made by Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). These highlight periods during which 2-Day westward propagating wave-number 3 waves are evident in the mesosphere and lower thermosphere. The ionospheric data-set is Total Electron Content (TEC), which is used to identify periods during which the ionosphere appears to respond to the planetary waves. Data from KP and F10.7 indices are used to determine events that may be of external origin. A 17-year time-span from 2002 to 2018 is used for this analysis so that both times of solar minimum and maximum can be studied. To extract the periods of this collection of data a Morlet Wavelet analysis is used, along with thresholding to indicate events when similar periods are seen in each data-set. Trends are then determined, which can lead to verification of previous assumptions and new discoveries. / Master of Science / The thermosphere and ionosphere are impacted by many sources. The sun and the magnetosphere externally impact this system. Planetary waves, which originate in the lower atmosphere, internally impact this system. This interaction leads to periodic signatures in the ionosphere that reflect periodic signatures seen in the lower atmosphere, the sun and the magnetosphere. This study identifies these times of similar oscillations in the neutral atmosphere, the ionosphere, and the sun, in order to characterize these interactions. Events are cataloged through wavelet analysis and thresholding techniques. Using a time-span of 17 years, trends are identified using histograms and percentages. From these trends, the characteristics of this coupling can be concluded. This study is meant to confirm the theory and provide new insights that will hopefully lead to further investigation through modeling. The goal of this study is to gain a better understanding of the role that planetary waves have on the interaction of the atmosphere and the ionosphere.

<p>The results presented in this PhD thesis are mainly based on measurements collected by the advanced sub-mm radiometer (SMR) aboard the Odin satellite in 2002-2007. The primary data are series of temperature and ozone profiles in the middle atmosphere up to 68 km. These data are used to estimate global properties of planetary wave propagation in both horizontal and vertical directions. As good-quality retrievals from Odin are not available above 68 km, additional data sources have been considered in order to extend coverage of planetary wave properties to higher levels. These sources are temperature observations at 85-90 km obtained by the ground-based meteor radars located in the polar region in the Northern Hemisphere in Scandinavia at Esrange and at Andenes, and in Canada at Resolute Bay and at Yellowknife. Also, the series of ozone profiles from the ground-based Kiruna mm-wave radiometer, KIMRA, are used in order to compare the wave properties in ozone fields measured globally by Odin and locally by KIMRA.</p><p>The main task of this PhD thesis is to study the 5-day planetary wave characteristics in the Earth’s atmosphere. The influence of waves on the atmospheric circulation causes, for example, substantial local departures from radiative equilibrium, observed in the winter stratosphere and close to the summer mesopause. Seasonal variations of the 5-day planetary wave properties and physical phenomena related to these variations are also studied in this thesis.</p><p>During winter, planetary waves propagate freely in the vertical direction, and maximal wave amplitudes are found in the extratropical stratosphere. The Northern Hemisphere (NH) winter periods of 2002-2003 and 2005 have been examined and a comparison has been carried out between the planetary wave properties in temperature and ozone variations. In general, the results show an expected in-phase behavior between the temperature and ozone fields in the lower stratosphere (due to dynamic effects) and an out-of-phase pattern in the upper stratosphere (which is expected as a result of photochemical effects).</p><p>Earlier theoretical and experimental studies have shown that, despite unfavourable summertime wind conditions, 5-day planetary waves can be registered not only in the stratosphere but also at higher altitudes in the mesosphere. The NH summers of 2003-2005 and 2007 have been considered and results have confirmed the existence of 5-day planetary waves up to the mesopause level (85-90 km). The results demonstrate that, for different periods, the possible source of the observed waves could be located at lower altitudes in both hemispheres with successive propagation into the summer mesosphere, or the waves could be generated in-situ as a result of the baroclinic instability of summer easterly jet.</p>

The results presented in this PhD thesis are mainly based on measurements collected by the advanced sub-mm radiometer (SMR) aboard the Odin satellite in 2002-2007. The primary data are series of temperature and ozone profiles in the middle atmosphere up to 68 km. These data are used to estimate global properties of planetary wave propagation in both horizontal and vertical directions. As good-quality retrievals from Odin are not available above 68 km, additional data sources have been considered in order to extend coverage of planetary wave properties to higher levels. These sources are temperature observations at 85-90 km obtained by the ground-based meteor radars located in the polar region in the Northern Hemisphere in Scandinavia at Esrange and at Andenes, and in Canada at Resolute Bay and at Yellowknife. Also, the series of ozone profiles from the ground-based Kiruna mm-wave radiometer, KIMRA, are used in order to compare the wave properties in ozone fields measured globally by Odin and locally by KIMRA. The main task of this PhD thesis is to study the 5-day planetary wave characteristics in the Earth’s atmosphere. The influence of waves on the atmospheric circulation causes, for example, substantial local departures from radiative equilibrium, observed in the winter stratosphere and close to the summer mesopause. Seasonal variations of the 5-day planetary wave properties and physical phenomena related to these variations are also studied in this thesis. During winter, planetary waves propagate freely in the vertical direction, and maximal wave amplitudes are found in the extratropical stratosphere. The Northern Hemisphere (NH) winter periods of 2002-2003 and 2005 have been examined and a comparison has been carried out between the planetary wave properties in temperature and ozone variations. In general, the results show an expected in-phase behavior between the temperature and ozone fields in the lower stratosphere (due to dynamic effects) and an out-of-phase pattern in the upper stratosphere (which is expected as a result of photochemical effects). Earlier theoretical and experimental studies have shown that, despite unfavourable summertime wind conditions, 5-day planetary waves can be registered not only in the stratosphere but also at higher altitudes in the mesosphere. The NH summers of 2003-2005 and 2007 have been considered and results have confirmed the existence of 5-day planetary waves up to the mesopause level (85-90 km). The results demonstrate that, for different periods, the possible source of the observed waves could be located at lower altitudes in both hemispheres with successive propagation into the summer mesosphere, or the waves could be generated in-situ as a result of the baroclinic instability of summer easterly jet.

Die nichtlineare Wechselwirkung der Quasi Zwei-Tage-Welle (QZTW) mit anderen planetaren Wellen führt zu wesentlichen Amplitudenmodulationen der Zwei-Tage Welle und zu einer Reihe auftretender sekundärer Wellen. die Ergebnisse der verschiedenen Experimte zur Wechselwirkung der Quasi Zwei-Tage Welle mit jeweils der 10-Tage Welle, der 16-Tage Welle und der 5-Tage Welle zeigen, dass die Amplitude der QZTW unter der Wechselwirkung mit der der 16-Tage Welle und der 10-Tage Welle um bis zu 20 % reduziert wird. Die stationäre planetare Welle mit der zonalen Wellenzahl 1 (SPW1) scheint die wichtigste Rolle bei den nichtlinearen Wechselwirkungen mit der QZTW zu spielen, da die daraus entstehenden sekundären Wellen mit den Wellenzahlen 2 und 4 dieselbe Periode wie die QZTW haben. Die Überlagerung der Quasi Zwei-Tage Welle und ihrer sekundären Wellen verstärkt die Amplitude um bis zu 60 %. / The non-linear interaction of the quasi two-day wave (QTDW) with other planetary waves leads to remarkable amplitude modulations of the QTDW and to arising secondary waves. Results of several numerical experiments considering the behaviour of the QTDW in connection with the 16-, 10-, and 5-day wave have shown that the amplitude of the QTDW reduces under interaction with the 16DW and 10DW. The stationary planetary wave with zonal wave number 1 (SPW1) seems to play the most important role, because resulting secondary waves exhibit the same period as the QTDW. The superposition of these waves leads to an enhancement of the QTDW-amplitude up to 60 %. This means, that a strong amplification of the QTDW measured by RADAR instruments can be due to interaction between the QTDW and a strong SPW1.

Die Anregung von planetarer Wellenaktivität in der Südwinter Stratosphäre wird anhand von Beobachtungsdaten untersucht. Die statistischen Untersuchungen zeigen, dass dem nichtlinearen Antrieb, erzeugt durch Wechselwirkungen zwischen den transienten baroklinen Eddies, eine entscheidende Rolle zu kommt. Aus täglichen Stromfunktionsfeldern der Südhemisphäre ist dazu die Berechnung des nichtlinearen tiefpass gefilterten Antriebes für Wellen mit zonalen Wellenzahlen eins und zwei erfolgt. Eine CEOF Analyse mit anschliessender MSSA liefert dominante Strukturen, die die Wechselwirkungen zwischen Tropo- und Stratosphäre sehr gut beschreiben. Die aus der MSSA abgeleiteten vertikalen Ausbreitungszeiten stimmen mit denen aus der Literatur bekannten überein. / Using observational data the forcing of planetary wave variability in the southern winter hemisphere is examined. The statistical analyses point out clearly the important role of the nonlinear eddy forcing. We calculate the low pass filtered nonlinear eddy forcing for waves with wavenumbers one and two from daily streamfunction fields. Our approach combines a complex empirical function analysis with a multichannel singular spectrum analysis. The resulting eigenstructures can be used to explain the interaction between the Troposphere and Stratosphere. We compare the dominant vertical propagation time scales obtained from our analysis with results existing in literature and find good agreement.

A resposta oceânica a perturbações com períodos e comprimentos significativamente maiores que o período inercial e que o raio de deformação de Rossby se dá na forma de ondas de Rossby planetárias. Geralmente, as perturbações são atribuídas a variações no rotacional do vento via bombeamento de Ekman. A passagem dessas ondas causa deformação das isopicnais, podendo resultar em anomalias da temperatura da superfície do mar (TSM) por advecção vertical. Dependendo de como ocorre a interação ar-mar, anomalias de TSM podem alterar o campo de ventos ou serem alteradas por ele através de fluxo de calor. Este trabalho utiliza dez anos de dados de temperatura da superfície do mar, velocidade e direção dos ventos e anomalia da altura do mar obtidos por satélites para identificar regiões do oceano onde há forçamento direto do vento na geração de ondas planetárias que se propagam linearmente. Mapas de correlação cruzada entre essas variáveis permitiram identificar onde a interação entre o oceano e a atmosfera é linear. Um modelo simples de uma camada e meia forçado apenas pelo bombeamento de Ekman foi utilizado para testar se, nestas regiões, a variabilidade atmosférica seria suficiente para explicar a variabilidade das ondas de Rossby estimadas pelos dados altimétricos. A interação entre a TSM e a intensidade do vento no Atlântico sul tropical é distinta das demais bacias oceânicas. Das correlações entre a TSM e o rotacional da tensão de cisalhamento do vento, observou-se que a dinâmica de Ekman não é marcante no Índico. Nas regiões tropicais do Atlântico e do Pacífico, as previsões do modelo foram similares às observações. Por fim, foram obtidas evidências de geração e retroalimentação de ondas planetárias nas bordas leste do Atlântico e do Pacífico. / Rossby waves are the ocean response to perturbations whose temporal and spatial scales are significantly longer than both the inertial period and the Rossby radius of deformation. These perturbations are, more often than not, attributed to variations in the wind stress curl {\\em via} Ekman pumping. The waves cause isopycnal displacement which due to vertical advection may result in sea surface temperature (SST) anomalies. Depending on the ocean--atmosphere interaction, SST anomalies can either change the wind field or be changed by it due to the heat flux. This study makes use of ten years of satellite derived SST, wind vector, and sea surface height anomaly data to identify regions where there is direct wind forcing of linear Rossby waves. Cross-correlation maps between these variables show where linear interactions occur. A simple 1½ layer model forced by Ekman pumping was used to check if, in those regions, atmospheric variability alone can explain the observed Rossby wave variability as estimated from radar altimeter data. The interaction between SST and wind magnitude in the South Atlantic is distinct from all other ocean basins. SST and wind stress curl correlations show that the Ekman dynamics is not dominant in the Indian Ocean. In the tropical Atlantic and Pacific the model predictions are similar to the observations. Finally, evidence of genesis and feedback of planetary waves is presented for the eastern boundaries of the Atlantic and Pacific oceans.