{"id":{"repo_id":"cadiz","oai_identifier":"oai:rodin.uca.es:10498/39688"},"canonical_url":"https://search.dev.ndltd.org/etd/cadiz/oai:rodin.uca.es:10498/39688","repository":{"repo_id":"cadiz","name":"Universidad de Cadiz","base_url":"https://rodin.uca.es/oai/request"},"display":{"title":"Analysis of the spatio-temporal sea level variability in extreme regions using in-situ and satellite remote sensing data: South Shetland region (Antarctica)","abstract":"This thesis analysessea level variability in the South Shetland Islands through the integration of satellite altimetry, long-term in-situ oceanographic observations, and the analysis of extreme geophysical events. The study provides new insights into the processes that drive polar coastal environments. The validation of Sentinel-3A and Sentinel-3B altimetric sea level anomaly products against tide gauge data showed that the agreement between satellite and in-situ measurements was highly sensitive to processing parameters and environmental conditions. Optimised settings, particularly the use of nine surrounding measurements to the crossover and a sea state bias correction of 5% of the significant wave height, yielded the lowest discrepancies with tide gauge records. Sea ice was identified as the main limitation for altimetry in the region, introducing data gaps and contaminating altimeter returns. These results highlight the importance of methodological refinement, including adaptive masking and improved retracking, to increase the robustness of polar altimetry. Temperature series from LIVMAR (Livingston Island) and DECMAR (Deception Island) stations revealed clear seasonal cycles modulated by local processes. Volcanic and tectonic activity, such as the 2020 Orca seamount activity, were associated with thermal anomalies, while glacier meltwater discharge was linked to earlier and more variable minima at Livingston. Three phases of thermal evolution were identified over the last decade, reflecting the combined effects of regional atmospheric variability and local geophysical forcing. In addition, the January 2022 Hunga Tonga–Hunga Ha’apai eruption generated atmospheric Lamb waves that were detected at Antarctic meteorological stations and triggered meteotsunamis at Livingston and Deception Islands. The responses at both sites highlight how atmospheric forcing generated long ocean waves that, once established, were shaped by local basin geometry in terms of amplitude and frequency. Overall, the results demonstrate that sea level variability in the South Shetland Islands is driven by the combined influence of large scale climatic factors, local volcanic and glacial processes, and extreme remote events. By integrating multiple approaches, this thesis contributes to reducing uncertainties in global sea level monitoring and to a more comprehensive understanding of sea level variability in this region of Antarctica.","abstract_html":"This thesis analysessea level variability in the South Shetland Islands through the integration of satellite altimetry, long-term in-situ oceanographic observations, and the analysis of extreme geophysical events. The study provides new insights into the processes that drive polar coastal environments. The validation of Sentinel-3A and Sentinel-3B altimetric sea level anomaly products against tide gauge data showed that the agreement between satellite and in-situ measurements was highly sensitive to processing parameters and environmental conditions. Optimised settings, particularly the use of nine surrounding measurements to the crossover and a sea state bias correction of 5% of the significant wave height, yielded the lowest discrepancies with tide gauge records. Sea ice was identified as the main limitation for altimetry in the region, introducing data gaps and contaminating altimeter returns. These results highlight the importance of methodological refinement, including adaptive masking and improved retracking, to increase the robustness of polar altimetry. Temperature series from LIVMAR (Livingston Island) and DECMAR (Deception Island) stations revealed clear seasonal cycles modulated by local processes. Volcanic and tectonic activity, such as the 2020 Orca seamount activity, were associated with thermal anomalies, while glacier meltwater discharge was linked to earlier and more variable minima at Livingston. Three phases of thermal evolution were identified over the last decade, reflecting the combined effects of regional atmospheric variability and local geophysical forcing. In addition, the January 2022 Hunga Tonga–Hunga Ha’apai eruption generated atmospheric Lamb waves that were detected at Antarctic meteorological stations and triggered meteotsunamis at Livingston and Deception Islands. The responses at both sites highlight how atmospheric forcing generated long ocean waves that, once established, were shaped by local basin geometry in terms of amplitude and frequency. Overall, the results demonstrate that sea level variability in the South Shetland Islands is driven by the combined influence of large scale climatic factors, local volcanic and glacial processes, and extreme remote events. By integrating multiple approaches, this thesis contributes to reducing uncertainties in global sea level monitoring and to a more comprehensive understanding of sea level variability in this region of Antarctica.","abstract_has_math":false,"creators":["Luengo Sánchez, Olga"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Berrocoso Domínguez, Manuel","Gómez Enri, Jesús"],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026","date_published":"2026","updated_at":"2026-07-24T01:29:47Z","subjects":[],"languages":["eng"],"rights":["Attribution-NonCommercial-NoDerivatives 4.0 Internacional"],"rights_urls":["http://creativecommons.org/licenses/by-nc-nd/4.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10498/39688","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Berrocoso Domínguez, Manuel","Gómez Enri, Jesús"]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Física Aplicada","Matemáticas"]},{"key":"dc:creator","label":"Author","values":["Luengo Sánchez, Olga"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-06-03T07:32:20Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-06-03T07:32:20Z"]},{"key":"dc:date.issued","label":"Date","values":["2026"]},{"key":"dc:type","label":"Dc Type","values":["doctoral thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Attribution-NonCommercial-NoDerivatives 4.0 Internacional"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://creativecommons.org/licenses/by-nc-nd/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10498/39688"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis analysessea level variability in the South Shetland Islands through the integration of satellite altimetry, long-term in-situ oceanographic observations, and the analysis of extreme geophysical events. The study provides new insights into the processes that drive polar coastal environments. The validation of Sentinel-3A and Sentinel-3B altimetric sea level anomaly products against tide gauge data showed that the agreement between satellite and in-situ measurements was highly sensitive to processing parameters and environmental conditions. Optimised settings, particularly the use of nine surrounding measurements to the crossover and a sea state bias correction of 5% of the significant wave height, yielded the lowest discrepancies with tide gauge records. Sea ice was identified as the main limitation for altimetry in the region, introducing data gaps and contaminating altimeter returns. These results highlight the importance of methodological refinement, including adaptive masking and improved retracking, to increase the robustness of polar altimetry. Temperature series from LIVMAR (Livingston Island) and DECMAR (Deception Island) stations revealed clear seasonal cycles modulated by local processes. Volcanic and tectonic activity, such as the 2020 Orca seamount activity, were associated with thermal anomalies, while glacier meltwater discharge was linked to earlier and more variable minima at Livingston. Three phases of thermal evolution were identified over the last decade, reflecting the combined effects of regional atmospheric variability and local geophysical forcing. In addition, the January 2022 Hunga Tonga–Hunga Ha’apai eruption generated atmospheric Lamb waves that were detected at Antarctic meteorological stations and triggered meteotsunamis at Livingston and Deception Islands. The responses at both sites highlight how atmospheric forcing generated long ocean waves that, once established, were shaped by local basin geometry in terms of amplitude and frequency. Overall, the results demonstrate that sea level variability in the South Shetland Islands is driven by the combined influence of large scale climatic factors, local volcanic and glacial processes, and extreme remote events. By integrating multiple approaches, this thesis contributes to reducing uncertainties in global sea level monitoring and to a more comprehensive understanding of sea level variability in this region of Antarctica.","Questa tesi analizza la variabilità del livello del mare in vicinanza delle Isole South Shetland, attraverso l’integrazione di altimetria satellitare, osservazioni oceanografiche in-situ e l’analisi di eventi geofisici estremi. Lo studio fornisce nuove prospettive sui processi che regolano gli ambienti costieri polari. La validazione dei prodotti altimetrici di anomalia del livello del mare dei satelliti Sentinel-3A e Sentinel-3B rispetto ai dati mareografici ha mostrato che la concordanza tra le misure satellitari e quelle in-situ è altamente sensibile ai parametri di elaborazione e alle condizioni ambientali. L’ottimizzazione delle impostazioni, in particolare l’utilizzo di nove misure circostanti nei punti di crossover e una correzione del bias per lo stato del mare pari al 5% dell’altezza d’onda significativa, hanno prodotto le discrepanze minori rispetto ai livelli registri dai mareografi. Il ghiaccio marino è stato identificato come la principale limitazione per l’altimetria satellitare nella regione, a causa di lacune nei dati e contaminazione degli echi altimetrici. Questi risultati evidenziano come il perfezionamento metodologico, che comprende l’impiego di tecniche di filtraggio adattativo e algoritmi di retracking avanzati, sia fondamentale per migliorare l’affidabilità delle misure altimetriche in ambiente polare. Le serie di temperatura delle stazioni mareografiche LIVMAR (Livingston Island) e DECMAR (Deception Island) hanno rivelato cicli stagionali ben definiti, modulati da processi locali. L’attività vulcanica e tettonica, tra cui quella registrata sulla montagna sottomarina Orca nel 2020, è risultata associata ad anomalie termiche, mentre il deflusso di acqua di fusione glaciale è stato collegato a minimi di temperatura più precoci e variabili presso Livingston. Negli ultimi dieci anni sono state identificate tre fasi di evoluzione termica, che riflettono gli effetti combinati della variabilità atmosferica regionale e delle forzanti geofisiche locali. L’eruzione del vulcano sottomarino Hunga Tonga–Hunga Ha’apai, nel gennaio 2022, d’altra parte ha generato onde atmosferiche di Lamb rilevate anche presso stazioni meteorologiche antartiche, e ha innescato meteotsunami a Livingston e Deception Island. Le risposte osservate in entrambi i siti mostrano come la forzante atmosferica abbia generato onde oceaniche di lungo periodo, modulate dalla geometria locale dei bacini in termini di ampiezza e frequenza. Nel complesso, la variabilità del livello del mare nelle Isole South Shetland risulta controllata dall’influenza combinata di fattori climatici su larga scala, processi vulcanici e glaciali locali, ed eventi estremi anche remoti. Integrando approcci diversi, il contributo di questo studio aiuta a ridurre le incertezze sul monitoraggio del livello marino a scala globale, e fornisce una più completa comprensione della sua variabilità nella regione antartica presa in esame.","Esta tesis analiza la variabilidad del nivel del mar en las islas Shetland del Sur a través de la integración de altimetría satelital, observaciones oceanográficas in-situ y el análisis de eventos geofísicos extremos. El estudio proporciona nuevas perspectivas sobre los procesos que controlan los entornos costeros polares. La validación de los productos altimétricos de anomalía del nivel del mar de Sentinel-3A y Sentinel-3B frente a los datos de mareógrafos mostró que la concordancia entre las mediciones satelitales e in situ es altamente sensible a los parámetros de procesado y a las condiciones ambientales. Los ajustes optimizados, en particular, el uso de nueve mediciones circundantes a los puntos de cruce del altímetro y una corrección del sesgo por estado del mar del 5% de la altura significativa de ola, dieron lugar a las menores discrepancias respecto a los registros mareográficos. El hielo marino fue identificado como la principal limitación para la altimetría en la región, generando lagunas de datos y contaminando el retracking del altímetro. Estos resultados evidencian la necesidad de perfeccionar la metodología, mediante un filtrado adaptativo de los datos y mejoras en los algoritmos de retracking, con el objetivo de aumentar la fiabilidad de la altimetría en regiones polares. Las series de temperatura de las estaciones LIVMAR (isla Livingston) y DECMAR (isla Decepción) revelaron ciclos estacionales claros modulados por procesos locales. La actividad volcánica y tectónica, como la registrada en el monte submarino Orca en 2020, se asoció a anomalías térmicas, mientras que la descarga de agua de deshielo glaciar estuvo vinculada a temperaturas mínimas más tempranas y variables en Livingston. En la última década se identificaron tres fases de evolución térmica, reflejando los efectos combinados de la variabilidad atmosférica regional y del forzamiento geofísico local. Asimismo, la erupción del Hunga Tonga-Hunga Ha'apai en enero de 2022 generó ondas de Lamb atmosféricas que fueron detectadas en estaciones meteorológicas antárticas y desencadenaron meteotsunamis en las islas Livingston y Decepción. Las respuestas en ambos emplazamientos evidencian cómo el forzamiento atmosférico generó ondas oceánicas largas que, una vez establecidas, fueron moduladas por la geometría local de las cuencas en términos de amplitud y frecuencia. En conjunto, los resultados demuestran que la variabilidad del nivel del mar en las islas Shetland del Sur está controlada por la influencia combinada de factores climáticos a gran escala, procesos volcánicos y glaciares locales, y eventos extremos remotos. Mediante la integración de múltiples enfoques, esta tesis contribuye a reducir las incertidumbres en la monitorización global del nivel del mar, así como una comprensión más integral de la variabilidad del nivel del mar en esta región de la Antártida."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Analysis of the spatio-temporal sea level variability in extreme regions using in-situ and satellite remote sensing data: South Shetland region (Antarctica)"]}]}],"canonical_facts":{"dc:contributor.advisor":["Berrocoso Domínguez, Manuel","Gómez Enri, Jesús"],"dc:contributor.other":["Física Aplicada","Matemáticas"],"dc:creator":["Luengo Sánchez, Olga"],"dc:date.accessioned":["2026-06-03T07:32:20Z"],"dc:date.available":["2026-06-03T07:32:20Z"],"dc:date.issued":["2026"],"dc:description.abstract":["This thesis analysessea level variability in the South Shetland Islands through the integration of satellite altimetry, long-term in-situ oceanographic observations, and the analysis of extreme geophysical events. The study provides new insights into the processes that drive polar coastal environments. The validation of Sentinel-3A and Sentinel-3B altimetric sea level anomaly products against tide gauge data showed that the agreement between satellite and in-situ measurements was highly sensitive to processing parameters and environmental conditions. Optimised settings, particularly the use of nine surrounding measurements to the crossover and a sea state bias correction of 5% of the significant wave height, yielded the lowest discrepancies with tide gauge records. Sea ice was identified as the main limitation for altimetry in the region, introducing data gaps and contaminating altimeter returns. These results highlight the importance of methodological refinement, including adaptive masking and improved retracking, to increase the robustness of polar altimetry. Temperature series from LIVMAR (Livingston Island) and DECMAR (Deception Island) stations revealed clear seasonal cycles modulated by local processes. Volcanic and tectonic activity, such as the 2020 Orca seamount activity, were associated with thermal anomalies, while glacier meltwater discharge was linked to earlier and more variable minima at Livingston. Three phases of thermal evolution were identified over the last decade, reflecting the combined effects of regional atmospheric variability and local geophysical forcing. In addition, the January 2022 Hunga Tonga–Hunga Ha’apai eruption generated atmospheric Lamb waves that were detected at Antarctic meteorological stations and triggered meteotsunamis at Livingston and Deception Islands. The responses at both sites highlight how atmospheric forcing generated long ocean waves that, once established, were shaped by local basin geometry in terms of amplitude and frequency. Overall, the results demonstrate that sea level variability in the South Shetland Islands is driven by the combined influence of large scale climatic factors, local volcanic and glacial processes, and extreme remote events. By integrating multiple approaches, this thesis contributes to reducing uncertainties in global sea level monitoring and to a more comprehensive understanding of sea level variability in this region of Antarctica.","Questa tesi analizza la variabilità del livello del mare in vicinanza delle Isole South Shetland, attraverso l’integrazione di altimetria satellitare, osservazioni oceanografiche in-situ e l’analisi di eventi geofisici estremi. Lo studio fornisce nuove prospettive sui processi che regolano gli ambienti costieri polari. La validazione dei prodotti altimetrici di anomalia del livello del mare dei satelliti Sentinel-3A e Sentinel-3B rispetto ai dati mareografici ha mostrato che la concordanza tra le misure satellitari e quelle in-situ è altamente sensibile ai parametri di elaborazione e alle condizioni ambientali. L’ottimizzazione delle impostazioni, in particolare l’utilizzo di nove misure circostanti nei punti di crossover e una correzione del bias per lo stato del mare pari al 5% dell’altezza d’onda significativa, hanno prodotto le discrepanze minori rispetto ai livelli registri dai mareografi. Il ghiaccio marino è stato identificato come la principale limitazione per l’altimetria satellitare nella regione, a causa di lacune nei dati e contaminazione degli echi altimetrici. Questi risultati evidenziano come il perfezionamento metodologico, che comprende l’impiego di tecniche di filtraggio adattativo e algoritmi di retracking avanzati, sia fondamentale per migliorare l’affidabilità delle misure altimetriche in ambiente polare. Le serie di temperatura delle stazioni mareografiche LIVMAR (Livingston Island) e DECMAR (Deception Island) hanno rivelato cicli stagionali ben definiti, modulati da processi locali. L’attività vulcanica e tettonica, tra cui quella registrata sulla montagna sottomarina Orca nel 2020, è risultata associata ad anomalie termiche, mentre il deflusso di acqua di fusione glaciale è stato collegato a minimi di temperatura più precoci e variabili presso Livingston. Negli ultimi dieci anni sono state identificate tre fasi di evoluzione termica, che riflettono gli effetti combinati della variabilità atmosferica regionale e delle forzanti geofisiche locali. L’eruzione del vulcano sottomarino Hunga Tonga–Hunga Ha’apai, nel gennaio 2022, d’altra parte ha generato onde atmosferiche di Lamb rilevate anche presso stazioni meteorologiche antartiche, e ha innescato meteotsunami a Livingston e Deception Island. Le risposte osservate in entrambi i siti mostrano come la forzante atmosferica abbia generato onde oceaniche di lungo periodo, modulate dalla geometria locale dei bacini in termini di ampiezza e frequenza. Nel complesso, la variabilità del livello del mare nelle Isole South Shetland risulta controllata dall’influenza combinata di fattori climatici su larga scala, processi vulcanici e glaciali locali, ed eventi estremi anche remoti. Integrando approcci diversi, il contributo di questo studio aiuta a ridurre le incertezze sul monitoraggio del livello marino a scala globale, e fornisce una più completa comprensione della sua variabilità nella regione antartica presa in esame.","Esta tesis analiza la variabilidad del nivel del mar en las islas Shetland del Sur a través de la integración de altimetría satelital, observaciones oceanográficas in-situ y el análisis de eventos geofísicos extremos. El estudio proporciona nuevas perspectivas sobre los procesos que controlan los entornos costeros polares. La validación de los productos altimétricos de anomalía del nivel del mar de Sentinel-3A y Sentinel-3B frente a los datos de mareógrafos mostró que la concordancia entre las mediciones satelitales e in situ es altamente sensible a los parámetros de procesado y a las condiciones ambientales. Los ajustes optimizados, en particular, el uso de nueve mediciones circundantes a los puntos de cruce del altímetro y una corrección del sesgo por estado del mar del 5% de la altura significativa de ola, dieron lugar a las menores discrepancias respecto a los registros mareográficos. El hielo marino fue identificado como la principal limitación para la altimetría en la región, generando lagunas de datos y contaminando el retracking del altímetro. Estos resultados evidencian la necesidad de perfeccionar la metodología, mediante un filtrado adaptativo de los datos y mejoras en los algoritmos de retracking, con el objetivo de aumentar la fiabilidad de la altimetría en regiones polares. Las series de temperatura de las estaciones LIVMAR (isla Livingston) y DECMAR (isla Decepción) revelaron ciclos estacionales claros modulados por procesos locales. La actividad volcánica y tectónica, como la registrada en el monte submarino Orca en 2020, se asoció a anomalías térmicas, mientras que la descarga de agua de deshielo glaciar estuvo vinculada a temperaturas mínimas más tempranas y variables en Livingston. En la última década se identificaron tres fases de evolución térmica, reflejando los efectos combinados de la variabilidad atmosférica regional y del forzamiento geofísico local. Asimismo, la erupción del Hunga Tonga-Hunga Ha'apai en enero de 2022 generó ondas de Lamb atmosféricas que fueron detectadas en estaciones meteorológicas antárticas y desencadenaron meteotsunamis en las islas Livingston y Decepción. Las respuestas en ambos emplazamientos evidencian cómo el forzamiento atmosférico generó ondas oceánicas largas que, una vez establecidas, fueron moduladas por la geometría local de las cuencas en términos de amplitud y frecuencia. En conjunto, los resultados demuestran que la variabilidad del nivel del mar en las islas Shetland del Sur está controlada por la influencia combinada de factores climáticos a gran escala, procesos volcánicos y glaciares locales, y eventos extremos remotos. Mediante la integración de múltiples enfoques, esta tesis contribuye a reducir las incertidumbres en la monitorización global del nivel del mar, así como una comprensión más integral de la variabilidad del nivel del mar en esta región de la Antártida."],"dc:format":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10498/39688"],"dc:language.iso":["eng"],"dc:rights":["Attribution-NonCommercial-NoDerivatives 4.0 Internacional"],"dc:rights.uri":["http://creativecommons.org/licenses/by-nc-nd/4.0/"],"dc:title":["Analysis of the spatio-temporal sea level variability in extreme regions using in-situ and satellite remote sensing data: South Shetland region (Antarctica)"],"dc:type":["doctoral thesis"]},"updated_at":"2026-07-24T01:29:47Z"}