Meteorološka analiza vremenskih uvjeta i rekonstrukcija požara u Istri 9. srpnja 2022.

master's thesis

• Title (english): Meteorological analysis of weather conditions and reconstruction of the wildfire in Istria on July 9, 2022
• Author: Jasmina Dobranić
• Mentor: Maja Telišman Prtenjak (mentor)
• Mentor: Ivana Čavlina Tomašević (komentor)
• Committee member: Maja Telišman Prtenjak (predsjednik povjerenstva)
• Committee member: Ivana Čavlina Tomašević (član povjerenstva)
• Committee member: Antun Marki (član povjerenstva)
• Committee member: Snježana Markušić (član povjerenstva)
• Committee member: Branko Grisogono (član povjerenstva)
• Committee member: Giuliana Verbanac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geophysics); Zagreb
• Defense date and country: 2024-05-09, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geophysics; Meteorology and Climatology

Abstract

U ovom radu detaljno je analizirana vremenska situacija za vrijeme požara kod Pule 9. srpnja 2022. godine. Napravljena je detaljna rekonstrukcija požara te su vremenski uvjeti povezani s ponašanjem požara u ovom slučaju. U požaru je izgorjelo oko 40 ha vegetacije, a požar je gorio unutar naseljenog područja. Uz napore vatrogasaca i naknadno poboljšanje vremenskih uvjeta, požar je stavljen pod nadzor nakon četiri sata, a u njemu je nastala samo materijalna šteta. Ocjena klimatskih prilika pokazala je da je srpnju 2022. godine prethodilo uglavnom sušno do vrlo sušno razdoblje te toplo do ekstremno toplo vrijeme, posebice u lipnju 2022. Požaru je prethodio toplinski val od 17 vrućih dana, a ukupna količina oborine 30 dana prije požara iznosila je 1,7 mm. Prema FWI indeksu postojala je velika do vrlo velika opasnost od izbijanja šumskih požara u danima koji su prethodili požaru. U sinoptičkoj analizi utvrđeno je da se nad područjem Istre rasprostiralo polje visokog tlaka, a frontalni sustavi su prolazili sjevernije. Dan prije izbijanja požara nad Istrom je prošao zapadni rub visinske ciklone te je nad područjem požara došlo do konvergencije i spuštanja suhog zraka. U analizi prizemnih podataka zabilježeno je da je požaru prethodilo toplo vrijeme s toplim noćima. Na sam dan požara maksimalna temperatura zraka dosegla je vrijednost od 27,5 °C, a relativna vlažnost zraka do 30 %. Dva sata prije i u trenutku izbijanja puhala je umjereno jaka bura sa žestokim udarima. Sredinom dana vjetar je oslabio i promijenio smjer na zapadni (smorac) što je pomoglo vatrogascima u stavljanju požara pod nadzor. U dnevniku motrenja postaje Pula-aerodrom evidentirana je pojava oblaka pirokumulusa. S obzirom na rijetka i udaljena radiosondažna mjerenja, analizirani su simulirani vertikalni profili za svaka tri sata dobiveni numeričkim modelom ALADIN-HR2. Opažena je pojava niske mlazne struje nekoliko sati prije izbijanja požara. Prizemna meteorološka polja dobivena numeričkim modelom prilično se poklapaju s mjerenjima.

Abstract (english)

In this paper, a detailed analysis of the weather conditions prior and during the fire near Pula on July 9, 2022, is presented. A detailed reconstruction of the wildfire was prepared, and the weather conditions were linked with the fire behavior in this case. The wildfire burned approximately 40 ha of vegetation within inhabited area. With the efforts of firefighters and subsequent improvement of weather conditions, the wildfire was brought under control after four hours, resulting in only material damage. Evaluation of climate conditions indicated, that prior to the wildfire conditions were mostly dry to very dry and warm to extremely warm, especially in June 2022. The wildfire was preceded by the heatwave of 17 hot days, and the total amount of precipitation 30 days before the wildfire was 1.7 mm. According to FWI, there was high to very high forest fire risk in days that preceded the wildfire. Using synoptic analysis, it was revealed that there was a high-pressure system dominating the area of the wildfire while frontal systems were passing further north. The day before the ignition, the western edge of deep upper-level shortwave trough passed over the Istria region leading to convergence and subsidence of dry air over the wildfire area. Surface measurements recorded warm weather with warm nights preceding the wildfire. On the day of the ignition, the maximum air temperature reached 27.5 °C, and relative humidity dropped to 30 %. Two hours prior and at the time of the ignition, moderately strong bura wind with strong gusts dominated the fire behavior. In the middle of the day the bura wind weakened and wind drifted to westerly direction (sea breeze), which helped firefighters to put the fire under control. The occurrence of pyrocumulus cloud was recorded in the observation of the Pula-airport station. Due to rare and distant radiosonde measurements, simulated vertical profiles were analyzed for every three hours from the numerical model ALADIN-HR2. The low-level jet occurred couple of hours before fire ignition. Surface meteorological fields obtained from the numerical model are closely correlated with surface measurement.

• Keywords: požar u Istri; Pula; ALADIN; bura; smorac; niska mlazna struja
• Keywords (english): wildfire; meteorological analysis; ALADIN; bura wind; sea breeze; low-level jet
• Language: croatian
• URN:NBN: urn:nbn:hr:217:641703
• 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: 2024-05-15 08:39:43