Simulacije ljetne oborine modelom Speedy

master's thesis

• Title (english): Simulations of summer precipitation with the Speedy model
• Author: Filip Suk
• Mentor: Ivana Herceg Bulić (mentor)
• Mentor: Sara Ivasić (komentor)
• Committee member: Ivana Herceg Bulić (predsjednik povjerenstva)
• Committee member: Antun Marki (član povjerenstva)
• Committee member: Iva Dasović (član povjerenstva)
• Committee member: Branimir Omazić (član povjerenstva)
• Committee member: Josip Stipčević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geophysics); Zagreb
• Defense date and country: 2024-09-18, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geophysics; Meteorology and Climatology

Abstract

El Niño – južna oscilacija (engl. El Niño – Southern Oscillation, ENSO) je naziv za mod međugodišnje varijabilnosti koja je povezana s promjenama u vjetrovima i površinskoj temperaturi mora u području tropskog Pacifika. Promjene u tropskoj konvekciji utječu na opću cirkulaciju atmosfere, a učinci ENSO-a mogu se pomoću mehanizma daljinskih veza prenijeti do udaljenih područja širom svijeta. Utjecaji u Pacifiku su temeljito istraženi, dok se utjecaji na Europu i sjeverni Atlantik još uvijek istražuju, a nedavna istraživanja pokazuju da je utjecaj ENSO-a na europsku klimu nestacionaran i sezonski varijabilan. Pomoću numeričkih simulacija oborine modelom SPEEDY za razdoblje 1855. – 2010., u ovom radu je istražen utjecaj različitih oceanskih bazena na oborinu područja NAE (engl. North Atlantic-European) i PNA (engl. Pacific-North American) u sezoni JAS (engl. July-August-September). Na temelju izračunatog indeksa Niño 3.4 u sezoni JAS, godine su razvrstane u ENSO godine i ne-ENSO godine. Anomalije oborine numeričkih simulacija korištene su za izračun polja signala oborine koja su prikazana u polarnoj stereografskoj projekciji za područje sjeverne hemisfere od 40°N do 90°N. Pronađeno je da tropski Atlantik ima najveći utjecaj na oborinu područja NAE kada se gledaju sve godine, no tijekom El Niño godina tropski Pacifik je oceanski bazen s najviše utjecaja. Na kraju, polja signala su usrednjena preko područja NAE i PNA, te su relativni odnosi različitih oceanskih bazena prikazani pomoću histograma. Najveći porast signala oborine uočen je za mjesec rujan tijekom El Niño godina u oba područja, dok u srpnju i kolovozu signal nije značajno uvećan.

Abstract (english)

El Niño – Southern Oscillation (ENSO) is the mode of interannual variability associated with the changes in winds and sea surface temperatures in the tropical Pacific region. Changes in tropical convection affect the general circulation of the atmosphere and the effects of ENSO can be transferred to distant regions of the world through the mechanism of teleconnections. The impacts in the Pacific have been thoroughly studied, while the impacts on Europe and the North Atlantic are still being investigated. Recent research indicates that ENSO's influence on European climate is non-stationary and varies by season. This study investigates the influence of different oceanic basins on precipitation in the North Atlantic-European (NAE) and Pacific North-American (PNA) regions during the July-August-September (JAS) season, by using the precipitation data from numerical simulations with the SPEEDY model for the period 1855-2010. The years were classified into ENSO years and non-ENSO years based on the calculated Niño 3.4 index in the JAS season. Precipitation anomalies of the numerical simulations were used to calculate precipitation signal fields, which were then displayed using polar stereographic projection for the Northern Hemisphere from 40°N to 90°N. When considering all years, it was found that the tropical Atlantic has the greatest impact on precipitation in the NAE region, but during El Niño years, the tropical Pacific is the oceanic basin with the greatest impact. Finally, the signal fields are averaged over the NAE and PNA regions, and the relative contributions of different oceanic basins are presented using histograms. The greatest increase in precipitation signal is observed in September during El Niño years in both regions, while in July and August the signal did not significantly increase.

• Keywords: ENSO; daljinske veze; oborina; simulacije modelom SPEEDY
• Keywords (english): ENSO; teleconnections; precipitation; SPEEDY AGCM simulations
• Language: croatian
• URN:NBN: urn:nbn:hr:217:954437
• Project: Number: IP-2022-10-4144; Title: Klima i ekstremni vremenski uvjeti u prirodnom i urbanom okolišu Hrvatske; Title: Croatian climate and extreme conditions in urban and natural environment; Acronym: CroClimExtremes; Leader: Ivana Herceg Bulić; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Research Projects
• Study programme: Title: graduate academic research programme: Master of Physics – geophysics, modules: Seismology and solid Earth physics, Meteorology and physical oceanography; specializations in: Seismology and solid Earth physics, Meteorology and physical oceanography; Course: Meteorology and physical oceanography; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni magistar fizike – geofizike (sveučilišni magistar fizike – geofizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-10-07 08:10:51