Klimatologija visokofrekventnih oscilacija razine svjetskih mora

doctoral thesis

• Title (english): Climatology of high-frequency sea-level oscillations in the world ocean
• Author: Petra Zemunik
• Mentor: Ivica Vilibić (mentor)
• Committee member: Mirko Orlić (predsjednik povjerenstva)
• Committee member: Miroslava Pasarić (član povjerenstva)
• Committee member: Irena Ciglenečki-Jušić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geology); Zagreb
• Defense date and country: 2022-11-25, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Interdisciplinary Natural Sciences; Marine Science
• Universal decimal classification (UDC): 55 - Geology. Meteorology. Hydrology

Abstract

Posljednjih nekoliko desetljeća mnoge svjetske mareografske postaje su povećale razlučivost mjerenja, što je omogućilo istraživanja kratkoperiodičnih oscilacija razine mora te unaprijedilo proučavanje ekstremnih visina razine mora. Osim seizmičkih tsunamija, ekstremnim visinama razine mora doprinose i kratkoperiodične oscilacije generirane poremećajima u atmosferi, među kojima su najrazorniji meteorološki tsunamiji. Meteorološki tsunamiji su oscilacije razine mora koje se javljaju na periodima tsunamija (od nekoliko minuta do nekoliko sati) i generirane su intenzivnim putujućim atmosferskim poremećajima. U ovoj disertaciji su objedinjena svjetska minutna mjerenja visine razine mora na kojima je provedena kontrola kvalitete te izdvojen visokofrekventni signal (perioda T < 2 h). Kreiran je skup podataka pod imenom MISELA (engl. MInute SEa – Level Analysis data) koji obuhvaća mjerenja s 331 mareografske postaje u svijetu. Napravljene su statističke globalne i regionalne analize podataka te je načinjena klimatologija atmosferski uzrokovanih visokofrekventnih oscilacija razine mora. Kvantificirana je povezanost između visokofrekventnih oscilacija i sinoptičkih varijabli relevantnih za njihovu pojavu. Također, uočeni su karakteristični sinoptički uzorci tijekom meteoroloških tsunamija diljem svijeta. Uz globalnu analizu visokofrekventnog signala razine mora, u disertaciji je analiziran i fenomen marrobbio, meteorološki tsunami koji se javlja na obalama otoka Sicilije i Lampeduse. Analizirana su mjerenja iz 2007. godine tijekom koje je uočeno šest događaja marrobbia s rasponom oscilacija većim od 40 cm. Oscilacije su najveće u luci Mazara del Vallo, lokaciji poznatoj po učestaloj pojavi marrobbia, koja se nalazi na jugozapadnoj obali Sicilije.

Abstract (english)

During the last few decades, many global tide gauges have increased their sampling resolution, which enabled the research of short-period sea-level oscillations and improved assessments of sea-level extremes. Apart from seismic tsunamis, atmospherically-driven short-period oscillations and their extreme manifestations known as meteorological tsunamis are shown to contribute to extreme sea levels. Meteorological tsunamis are sea-level oscillations which occur on periods of seismic tsunamis (from a few minutes to a few hours) and are generated by intensive propagating atmospheric disturbances. In this thesis, available global 1-minute sea-level observations are merged and unified, then subjected to quality control procedures and finally filtered to extract their high-frequency signal (with period T < 2h). The dataset named MISELA (MInute SEa - Level Analysis data) has been created containing observations from 331 tide gauges worldwide. Global and regional statistical analyses have been conducted using the MISELA dataset and a climatology of atmospherically-induced high-frequency sea-level oscillations has been constructed. The connection between high-frequency oscillations and relevant synoptic variables has been quantified. Moreover, specific synoptic patterns have been recognized during meteorological tsunamis in many world regions. Along with global analyses of high-frequency signal, this thesis studies the phenomenon marrobbio, a meteorological tsunami which occurs on the coasts of Sicily and Lampedusa. The observations from 2007 have been analysed and six marrobbio events with a range of oscillations higher than 40 cm have been detected. The oscillations are shown to have the highest range in Mazara del Vallo, a known “hotspot“ of marrobbio, located at the southwest coast of Sicily.

• Keywords: razina mora; meteorološki tsunamiji; visokofrekventne oscilacije razine mora atmosferskog porijekla; mareografska mjerenja; interakcija atmosfere i mora; sinoptičke varijable; sinoptički indeks; marrobbio
• Keywords (english): sea level; meteorological tsunami; nonseismic high-frequency sea-level oscillations; tide gauge records; atmosphere-ocean interaction; synoptic variables; synoptic index; marrobbio
• Language: croatian
• URN:NBN: urn:nbn:hr:217:582480
• Project: Number: IP-2016-06-1955; Title: Višegodišnje i dekadne oscilacije Jadranskog mora: opažanja, modeliranje i posljedice; Acronym: ADIOS; Leader: Ivica Vilibić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Interdisciplinary doctoral study in Oceanology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje interdisciplinarne prirodne znanosti (znanost o moru) (doktor/doktorica znanosti, područje prirodnih znanosti, polje interdisciplinarne prirodne znanosti (znanost o moru))
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-01-23 10:18:30