Analiza uzroka noćne i ranojutarnje duboke konvekcije nad sjeveroistočnim Jadranom

master's thesis

• Title (english): Analysis of the causes of night and early morning deep convection over the north-eastern Adriatic
• Author: Anna-Maria Križanac
• Mentor: Maja Telišman Prtenjak (mentor)
• Committee member: Maja Telišman Prtenjak (predsjednik povjerenstva)
• Committee member: Antun Marki (član povjerenstva)
• Committee member: Ivica Sović (član povjerenstva)
• Committee member: Željko Večenaj (član povjerenstva)
• Committee member: Marijan Herak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geophysics); Zagreb
• Defense date and country: 2020-12-01, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geophysics; Meteorology and Climatology

Abstract

U ovom radu napravljena je sinoptička i mezoskalna analiza pet odabranih slučajeva tuče u Tršćanskom zaljevu i Istri tijekom vremenskog razdoblja 2010.-2014. Analiza je napravljena s ciljem boljeg razumijevanja uzroka pojačane (rano)jutarnje konvektivne aktivnosti. Tip sinoptičkih uvjeta subjektivno je procijenjen na temelju sinoptičkih karata i profila radiosondažnih mjerenja u terminima 12:00 i 00:00 UTC s postaje Udine. Prilikom analiza svakog slučaja, mezoskalnim numeričkim modelom WRF, pokušali su se reproducirati uvjeti koji su pogodovali razvoju konvekcije i nastanku tuče. Modelirana polja uspoređena su s podacima prikupljenim na 34 meteorološke/klimatološke postaje nepravilno raspoređene u Istri. Provela se usporedba parametara tuče dobivenih specijalnim mjerenjima iz mreže tučomjera s rezultatima modela WRF-HAILCAST kao i usporedba mjerenih udara munja iz LINET mreže s prognoziranim potencijalom za razvoj munja iz modela WRF. Usporedbe provedene na pet odabrabih slučajeva dale su zadovoljavajuće rezultate te ukazale na korisnost primjene ovih algoritama. Numeričke simulacije dale su dalje uvid u prostorno-vremenske karakteristike konvekcije na sjevernom Jadranu te razlučile razne doprinose sinoptičkih i mezoskalnih procesa. U tri analizirana slučaja sinoptičko strujanje nad Istrom onemogućilo je značajniji razvoj termičko-generiranog strujanja manjih mezoskalnih dimenzija. Ipak u dva slučaja termičko-generirani vjetar manje skale se superponirao na sinoptički vjetar veće skale i tako imao upliv na razvoj konvekcije. Glavna je posljedica bila stvaranje niza značajnih zona konvergencije u polju strujanja iznad mora zbog (i) generiranja strujanja koje je dolazilo s kopna na more te (ii) modifikacije strujanja iz južnog u jugoistočni smjer zbog oblika i visine obale nad istarskim poluotokom. Time je stvorena prizemna konvergencija vjetra pospješila stvaranje/održavanje konvektivnih ćelija.

Abstract (english)

In this paper, a synoptic and mesoscale analysis of five selected hail cases in the Gulf of Trieste and Istria during the period 2010-2014 was performed. The analysis was made with the aim of better understanding the causes of increased (early)morning convective activity. The type of synoptic conditions was subjectively assessed based on synoptic maps and profiles of radiosonde measurements at 12:00 and 00:00 UTC from Udine station. In the analysis of each case, using the mesoscale numerical model WRF, attempts were made to reproduce the conditions conducive to the development of convection and the occurrence of hail. The modeled fields were compared with data collected at 34 meteorological/climatological stations irregularly distributed in Istria. A comparison of hail parameters obtained by special measurements from the hail meter network with the results of the WRF-HAILCAST model was performed, as well as a comparison of measured lightning strikes from the LINET network with the predicted potential for lightning development from the WRF model. Comparisons conducted on five selected cases gave satisfactory results and indicated the usefulness of applying these algorithms. Numerical simulations gave further insight into the spatial-temporal characteristics of convection in the northern Adriatic and distinguished various contributions of synoptic and mesoscale processes. In three analyzed cases, the synoptic flow over Istria prevented a significant development of the thermally-generated flow of smaller mesoscale dimensions. Yet, in two cases, the thermally-generated wind of a smaller scale was superimposed on the synoptic wind of a larger scale and thus influenced the development of convection. The main consequence was the creation of several significant zones of convergence in the field of currents above sea level due to (i) generation of airflow coming from land to sea and (ii) modifications of currents from south to southeast due to the shape and height of the coast over the Istrian peninsula. The resulting ground convergence of the wind facilitated the formation/maintenance of convective cells.

• Keywords: konvekcija; tuča; Istra; Tršćanski zaljev; WRF
• Keywords (english): convection; hail; Istria; Gulf of Trieste; WRF
• Language: croatian
• URN:NBN: urn:nbn:hr:217:972835
• Study programme: Title: Graduate university study pf Physics - Geophysics; specializations in: Seismology and Physics of the Earth's Interior, Meteorology and Physical Oceanography; Course: Seismology and Physics of the Earth's Interior; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra fizike – geofizike (magistar/magistra fizike – geofizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-01-11 10:52:32