2023. december 2. szombat

July - September 2022

Journal of the Hungarian Meteorological Service


letöltés [pdf: 2988 KB]
Heat capacity of the climate system derived from planetary radiation budget measurements
György Major
 PDF (379 KB)   |   Abstract

The new edition of the satellite measured radiation budget data have the smallest ever random and systematic error. From them, mean yearly cycle of the planetary heat capacity has been calculated for the period of 2000–2014. The radiation budget data measured before 2000 have serious systematic error. Using the new radiation budget data as well as the total solar irradiance data, the old yearly radiation budget values have been corrected.  From the corrected data, the average heat capacity of the climate system has been calculated for the 1964–2014 half century.

Remote sensing study of cloud top absolute temperature with surface rainfall over Lahore (Pakistan) during monsoon
Jahanzeb Qureshi and Noor Fatima
 PDF (1543 KB)   |   Abstract

The study attempts to build a relationship between clouds top absolute temperature and rainfall during monsoon period over Lahore during 2019. For this purpose, meteorological data was taken from Pakistan Meteorological Department (PMD) of few parameters (temperature and rainfall) for Lahore during monsoon period, i.e., from July to September, 2019. The study revealed interesting results for the observed three months. In July and August, the rainfall and temperature trend showed an inverse relation, whereas a decreased trend was observed for both temperature and rainfall during September, 2019. In Pakistan, most of the rainfall is a result of the depressions created over Bay of Bengal and Arabian Sea. High temperatures cause lower pressure that becomes a reason for originating of low pressures/depressions resulting in monsoon rainfall. During September, the average temperature of the study area was lower comparatively that ultimately resulted in low rainfall, and only 54 mm of total rainfall was recorded over Lahore during September, 2019 which was quite less than in July and August. Satellite cloud top temperatures were also taken from EUMETSAT to establish a relation between cloud top absolute temperature and surface rainfall over Lahore.

Frequency and variability trends of extreme meteorological events in theMoson Plain, Hungary (1961–2018)
Tamás Füzi and Márta Ladányi
 PDF (367 KB)   |   Abstract

Corresponding to the global trends, the territory of Hungary is endangered by extreme weather manifestations. The increased frequency of the unfavorable effects (inland water, flood, drought, heat stress) can be detected. These harmful manifestations result in a significant economic and environmental risk. To investigate adverse environmental effects and risks that have an impact on economic and productive activities is essential. The aim of our research is to present the transformation of the climatic system of the Moson Plain in the northwestern part of Hungary by analyzing special indicators based on daily temperature and precipitation data covering approximately two climatic cycles (1961–1990; 1991–2018). Based on our results, we can report the formation of a warming microclimate with whimsical precipitation rates, which is accompanied by a decrease in low temperature values. At the same time, we can observe more prominent manifestations
of heat waves.

Precipitation trends in Turkey (1969–2018): A spatiotemporal analysis
Saffet Erdoğan, Mustafa Ulukavak, and Mehmet Yılmaz
 PDF (1795 KB)   |   Abstract

Global climate change can have significant impacts on different geographical regions. It is very important to analyze the changes in temporal and spatial precipitation patterns. In this study, the monthly and yearly precipitation values in Turkey were examined by combining the nonparametric Mann-Kendall rank correlation test and Getis-Ord G spatial clustering test. The study was carried out by integrating and compiling the data in different formats related to the years 1969–2018 for 233 stations in Turkey. It was observed that the annual total precipitation amounts had decreased significantly in many stations during the studied period. Though most of the stations show a decreasing trend in annual precipitation, only the inner and southern part of the country has significant decreasing trends. The trend analysis on monthly precipitation data reveals that there are significant (confidence level ≥ 95%) decreasing trends in most of the regions of Turkey.

The analysis of annual and seasonal surface air temperature trends of southern and southeastern Bosnia and Herzegovina from 1961 to 2017
Nikola R. Bačević, Nikola Milentijević, Aleksandar Valjarević, Milena Nikolić, Vladica Stevanović, Dušan Kićović, Milica G. Radaković, Dragan Papić, and Slobodan B. Marković
 PDF (1383 KB)   |   Abstract

In some areas of the world, regional climate change is in good agreement with global climate change. This study brings new information about what defines climate change in the contact area of Adriatic Sea and Southeastern Europe, and conclusions are based on trend analysis of annual and seasonal temperatures in the southern and southeastern parts of Bosnia and Herzegovina. Trend analysis was applied on mean annual surface air temperatures, mean maximum temperatures, and mean minimum temperatures of all four seasons. This study used 4 meteorological stations: Livno, Bileća, Mostar, and Ivan Sedlo for 56 years. The main statistical method is the Mann-Kendall test. The total number of analysis is 48. A statistically significant positive trend was determined in 36 analysis, while in the rest of the tests this was not the case. The highest amount of temperature increase is present in the mean maximum summer air temperatures in Livno and Ivan Sedlo. Mean minimum autumn air temperatures had the smallest increase. Negative trend is present in the mean autumn surface air temperatures and mean maximum autumn temperatures. Using a geographical information system resulted in visualizing regional differences in the spatial distribution of isotherms. The study area has combined the influence of orography and maritime effects of the Adriatic Sea. Having in mind these results, the growing temperature has been recognized as a problem which needs more attention in Bosnia and Herzegovina. Unfortunately, official documents which propose economic adaptation on climate change in this country are not at a satisfactory level.

Markov chain analysis of the probability of days in a heat wave period
Árpád Fekete
 PDF (412 KB)   |   Abstract

The impact of global climate change is also felt in Hungary. An undesirable effect of climate change (associated with rising temperatures) is mainly the increase in the frequency, intensity, and length of summer heat waves. In this respect, the region of the Southern Great Plain and the Danube-Tisza Region are particularly endangered, but the number of heat wave days has increased throughout the country in recent decades.
This study takes the climatic data sets of Baja into account, and on this basis, it gives the probability that a particular day falls into a heat wave period. Based on this information we draw a general conclusion about the long-term change of this climatic characteristic of the Southern Great Plain. The mathematical model used in the research applies the theory of Markov chains, which is relatively new in statistical analysis.

Trend analysis of water flow on Neka and Tajan rivers using parametric and non-parametric tests
Mohammad Salarian, Shamim Larijani, Hossein Banejad, Mohammad Heydari, and Hamed Benisi Ghadim
 PDF (530 KB)   |   Abstract

River flow is an essential parameter in hydrology and water resources studies with mutual interaction with climate elements. So, studying the discharge change trend in the rivers is crucial for management programs and the design of irrigation and drainage systems. In the present study, river flow data measured at six hydrological stations at Neka (Ablu, Golverd, SefidChah) and Tajan (KordKhil, Rigcheshmeh, Soleimantangeh) rivers in Mazandaran Province have been studied by using Mann-Kendall test, age test, and regression analysis during the statistical period of 1976–2006. The MAKESENS 1.0 software was used to reveal annual and seasonal discharge change trends. Results of the present study showed that only two stations – Soleimantangeh and Rigcheshmeh – had decreasing trend at 5% significance level in yearly terms.
In contrast, the regression analysis showed just significant trends at Soleimantangeh station. No crucial trends have been observed in the seasonal scale; in spring and autumn, most of the stations had a non-significant negative trend. By considering the methods used to evaluate trends in this study (Mann-Kendall test, age test, and regression analysis), it was observed that all the rivers had had decreasing and negative trends. The performance of parametric and non-parametric tests was similar in most cases.

Observed climate changes in the Toplica river valley - Trend analysis of temperature, precipitation and river discharge
Nataša M. Martić Bursać, Milan M. Radovanović, Aleksandar R. Radivojević, Radomir D. Ivanović, Ljiljana S. Stričević, Milena J. Gocić, Ninoslav M. Golubović, and Branislav L. Bursać
 PDF (1420 KB)   |   Abstract

Changes in air temperature, precipitation, and the Toplica river discharge were investigated. Annual and seasonal climatic data were collected at weather stations Kursumlija and Prokuplje, and discharge data on hydrological gauges Pepeljevac and Doljevac. The data covered a period of 62 years (1957–2018). Mann-Kendall and Pettitt’s tests have been applied for the periods 1957–2018, 1957–1987, 1988–2018, and 1975–1994, which we find as very important period when atmospheric circulation was altered. Mean annual temperature and precipitation were greater in the second half-period, while the discharge was smaller, even all the signals had growth trend. Mean seasonal temperature increased for all seasons, as well as precipitation, except for summer (JJA). The discharge is lower in the second half-period for almost all seasons, with signs of recovery for all seasons except summer.