<p>Extreme compound events defined as the simultaneous occurrence of multiple natur... more <p>Extreme compound events defined as the simultaneous occurrence of multiple natural hazards such as floods, droughts, and heatwaves, have become increasingly frequent in South East Europe in recent years. These events can have significant impacts on the region's social, economic, and environmental systems and can lead to significant human losses. Because South East is identified as a climate hot spot for future climate change and occurrence of extreme compound events, it is very important to identify and study these hot spots. This information could be useful for decision-makers and practitioners in the water management and agriculture sector, especially in the Balkan region. Here we present the first results of the study of the compound warm and dry over the Western Balkan area since compound events have not been studied over the territory of Eastern Europe since 1950 until today. Using daily data on maximum temperature and precipitation, we calculated the frequency and trends of the warm/dry (WD) indices. Trends were calculated using the Mann-Kendall trend test in R and the resolution that was used is ERA5 1950-now. Presented results are annual and also seasonal variations. The index that we used shows cold and dry events per year or season, the results indicate the rising trend over the whole territory of South East Europe, where trends were statistically significant by over 95 percent. We investigated years with recorded heat waves and the most severe droughts in the observed region in the years: 2007, 2012, 2015, and 2017. In 2007 there were more than 140 warm and dry events in the Western Balkans area, in 2012 there were between 160 and 200 warm and dry events, in 2015 more than 140 and in 2017 around 140 warm and dry events. </p> <p>Studying extreme compound events is very important because it helps us to better understand the underlying causes of extreme weather and other natural disasters, especially in this area of high agricultural potential. This knowledge can help farmers to make informed decisions about how to identify potential risks and develop strategies to mitigate them to maximize their yields and minimize losses.</p> <p>Our results highlight the need for targeted and effective risk management strategies to reduce the negative impacts of extreme compound events in South East Europe.</p> <p> </p> <p> </p> <p><strong>KEY WORDS</strong></p> <p>Compound events, temperature, precipitation, Eastern Europe, trends</p> <p> </p> <p> </p> <p> </p> <p>Funding: This research was supported by the EXtremeClimTwin project, which has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No952384.</p>
The main source of error in user position system GPS (Global Positioning System) receivers using ... more The main source of error in user position system GPS (Global Positioning System) receivers using frequency, the effect is caused by the ionosphere on the signal transmitted by the satellites. This error is directly proportional to the total electron content (TEC) in the ionosphere and inversely proportional to the square of the frequency of the transmitted signal. The ionosphere, as a dispersive medium, affects the modulation and carrier phase, causing suffer respectively, a delay and an advance. The delay is referred to also as ionospheric delay and increases the apparent length of the path traveled by the signal. The TEC varies in time and space with respect to time (daily variation), the time of year (seasonal variation), the geographical location, the sunspot cycle (variation over time). This paper studied and assessed the variation of TEC for the month of April 2008, covering the Brazilian territory, through maps of VTEC (TEC in the vertical direction) using data from the globa...
Borisov, M., Govedarica, M., Orihan, M.: Rotacija Zemlje i određivanje parametara Zemljine rotaci... more Borisov, M., Govedarica, M., Orihan, M.: Rotacija Zemlje i određivanje parametara Zemljine rotacije 75 UDK 528.2 Pregledni rad SAŽETAK Zemljina orijentacija i rotacija Zemlje sa akcentom na određivanju parametara Zemljine orijentacije su opisani.. Tehnika koja je korištena za određivanje parametara naziva se tehnika dugobazisne interferometrije. Nakon određivanja parametara Zemljine orijentacije, upoređivani su dobiveni rezultati koristeći različite referentne okvire i analizirani su faktori koji utiču na njihove promene. Za poređenje su korišćeni vievstTrf i vtrf2008 referentni okviri. Obrada podataka je obavljena u softveru VieVS (Vienna VLBI Software). Podaci koji su korišteni pripadaju programu različitih serija koji se u kontinuitetu opažaju na svake tri godine. Ključne riječi: rotacija Zemlje, parametri Zemljine orijentacije, dugobazisna interferometrija, VLBI, EOP. ABSTRACT Earth's rotation and elements of the Earth's orientation, with emphasis on the determination of...
Zemljina orijentacija i rotacija Zemlje sa akcentom na određivanju parametara Zemljine orijentaci... more Zemljina orijentacija i rotacija Zemlje sa akcentom na određivanju parametara Zemljine orijentacije su opisani.. Tehnika koja je koristena za određivanje parametara naziva se tehnika dugobazisne interferometrije. Nakon određivanja parametara Zemljine orijentacije, upoređivani su dobiveni rezultati koristeci razlicite referentne okvire i analizirani su faktori koji uticu na njihove promene. Za poređenje su korisceni vievstTrf i vtrf2008 referentni okviri. Obrada podataka je obavljena u softveru VieVS (Vienna VLBI Software). Podaci koji su koristeni pripadaju programu razlicitih serija koji se u kontinuitetu opažaju na svake tri godine.
The paper deals with the themes of the Earth's orientation and rotation. The parameters of th... more The paper deals with the themes of the Earth's orientation and rotation. The parameters of the Earth'sorientation can be determined by several methods. The emphasis in this paper is the influence of oceantides to determine the parameters of the Earth's orientation with one of the space-geodetic techniques,called Very long baseline interferometry (VLBI). After determining the parameters, the results obtainedusing the VLBI were compared between reference system VieVS and Vrf2008, as well as influence ofocean tides and without its impact.When processing the data, the obtained results were compared using different reference systems andvarious that influence their changes were analyzed. The used data belong to different series of programsthat are continuously observed. The results are the product of software VieVS with data from acontinuing series CONT14.
<p>Extreme compound events defined as the simultaneous occurrence of multiple natur... more <p>Extreme compound events defined as the simultaneous occurrence of multiple natural hazards such as floods, droughts, and heatwaves, have become increasingly frequent in South East Europe in recent years. These events can have significant impacts on the region's social, economic, and environmental systems and can lead to significant human losses. Because South East is identified as a climate hot spot for future climate change and occurrence of extreme compound events, it is very important to identify and study these hot spots. This information could be useful for decision-makers and practitioners in the water management and agriculture sector, especially in the Balkan region. Here we present the first results of the study of the compound warm and dry over the Western Balkan area since compound events have not been studied over the territory of Eastern Europe since 1950 until today. Using daily data on maximum temperature and precipitation, we calculated the frequency and trends of the warm/dry (WD) indices. Trends were calculated using the Mann-Kendall trend test in R and the resolution that was used is ERA5 1950-now. Presented results are annual and also seasonal variations. The index that we used shows cold and dry events per year or season, the results indicate the rising trend over the whole territory of South East Europe, where trends were statistically significant by over 95 percent. We investigated years with recorded heat waves and the most severe droughts in the observed region in the years: 2007, 2012, 2015, and 2017. In 2007 there were more than 140 warm and dry events in the Western Balkans area, in 2012 there were between 160 and 200 warm and dry events, in 2015 more than 140 and in 2017 around 140 warm and dry events. </p> <p>Studying extreme compound events is very important because it helps us to better understand the underlying causes of extreme weather and other natural disasters, especially in this area of high agricultural potential. This knowledge can help farmers to make informed decisions about how to identify potential risks and develop strategies to mitigate them to maximize their yields and minimize losses.</p> <p>Our results highlight the need for targeted and effective risk management strategies to reduce the negative impacts of extreme compound events in South East Europe.</p> <p> </p> <p> </p> <p><strong>KEY WORDS</strong></p> <p>Compound events, temperature, precipitation, Eastern Europe, trends</p> <p> </p> <p> </p> <p> </p> <p>Funding: This research was supported by the EXtremeClimTwin project, which has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No952384.</p>
The main source of error in user position system GPS (Global Positioning System) receivers using ... more The main source of error in user position system GPS (Global Positioning System) receivers using frequency, the effect is caused by the ionosphere on the signal transmitted by the satellites. This error is directly proportional to the total electron content (TEC) in the ionosphere and inversely proportional to the square of the frequency of the transmitted signal. The ionosphere, as a dispersive medium, affects the modulation and carrier phase, causing suffer respectively, a delay and an advance. The delay is referred to also as ionospheric delay and increases the apparent length of the path traveled by the signal. The TEC varies in time and space with respect to time (daily variation), the time of year (seasonal variation), the geographical location, the sunspot cycle (variation over time). This paper studied and assessed the variation of TEC for the month of April 2008, covering the Brazilian territory, through maps of VTEC (TEC in the vertical direction) using data from the globa...
Borisov, M., Govedarica, M., Orihan, M.: Rotacija Zemlje i određivanje parametara Zemljine rotaci... more Borisov, M., Govedarica, M., Orihan, M.: Rotacija Zemlje i određivanje parametara Zemljine rotacije 75 UDK 528.2 Pregledni rad SAŽETAK Zemljina orijentacija i rotacija Zemlje sa akcentom na određivanju parametara Zemljine orijentacije su opisani.. Tehnika koja je korištena za određivanje parametara naziva se tehnika dugobazisne interferometrije. Nakon određivanja parametara Zemljine orijentacije, upoređivani su dobiveni rezultati koristeći različite referentne okvire i analizirani su faktori koji utiču na njihove promene. Za poređenje su korišćeni vievstTrf i vtrf2008 referentni okviri. Obrada podataka je obavljena u softveru VieVS (Vienna VLBI Software). Podaci koji su korišteni pripadaju programu različitih serija koji se u kontinuitetu opažaju na svake tri godine. Ključne riječi: rotacija Zemlje, parametri Zemljine orijentacije, dugobazisna interferometrija, VLBI, EOP. ABSTRACT Earth's rotation and elements of the Earth's orientation, with emphasis on the determination of...
Zemljina orijentacija i rotacija Zemlje sa akcentom na određivanju parametara Zemljine orijentaci... more Zemljina orijentacija i rotacija Zemlje sa akcentom na određivanju parametara Zemljine orijentacije su opisani.. Tehnika koja je koristena za određivanje parametara naziva se tehnika dugobazisne interferometrije. Nakon određivanja parametara Zemljine orijentacije, upoređivani su dobiveni rezultati koristeci razlicite referentne okvire i analizirani su faktori koji uticu na njihove promene. Za poređenje su korisceni vievstTrf i vtrf2008 referentni okviri. Obrada podataka je obavljena u softveru VieVS (Vienna VLBI Software). Podaci koji su koristeni pripadaju programu razlicitih serija koji se u kontinuitetu opažaju na svake tri godine.
The paper deals with the themes of the Earth's orientation and rotation. The parameters of th... more The paper deals with the themes of the Earth's orientation and rotation. The parameters of the Earth'sorientation can be determined by several methods. The emphasis in this paper is the influence of oceantides to determine the parameters of the Earth's orientation with one of the space-geodetic techniques,called Very long baseline interferometry (VLBI). After determining the parameters, the results obtainedusing the VLBI were compared between reference system VieVS and Vrf2008, as well as influence ofocean tides and without its impact.When processing the data, the obtained results were compared using different reference systems andvarious that influence their changes were analyzed. The used data belong to different series of programsthat are continuously observed. The results are the product of software VieVS with data from acontinuing series CONT14.
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