In lakes, several physical, chemical, and biological processes occur simultaneously, and these processes are interconnected. Therefore, the investigation of lakes requires a multidisciplinary approach that includes physics (including the physics of the atmosphere, i.e., meteorology), chemistry, geology, hydrogeology, hydrology and biology. Each of these disciplines addresses a lake from a different point of view. However, lake studies that primarily belong to one field, at least to some extent, report their findings in ways that are associated with other fields ; this type of reporting is caused by the inherent interconnections between phenomena from different disciplines. Plitvice Lakes, Croatia, are composed of a unique cascading chain of karst lakes, and these lakes have been investigated by numerous authors. Here, we provide an overview of the studies of the Plitvice Lakes Area (PLA) that address meteorology, climatology, hydrology, hydrogeochemistry and physical limnology. Our aim is to synthesize the results from each of these disciplines and make them available to scientists from other related disciplines ; thus, this review will facilitate further investigations of the PLA within the natural sciences. In addition, valuable results from early investigations of Plitvice Lakes are generally unavailable to the broader scientific community, and are written in Croatian. Here, we summarize these results and make them available to a wider audience.
{"title":"Review of research on Plitvice Lakes, Croatia in the fields of meteorology, climatology, hydrology, hydrogeochemistry and physical limnology","authors":"Z. Bencetić Klaić, J. Rubinić, S. Kapelj","doi":"10.15233/GFZ.2018.35.9","DOIUrl":"https://doi.org/10.15233/GFZ.2018.35.9","url":null,"abstract":"In lakes, several physical, chemical, and biological processes occur simultaneously, and these processes are interconnected. Therefore, the investigation of lakes requires a multidisciplinary approach that includes physics (including the physics of the atmosphere, i.e., meteorology), chemistry, geology, hydrogeology, hydrology and biology. Each of these disciplines addresses a lake from a different point of view. However, lake studies that primarily belong to one field, at least to some extent, report their findings in ways that are associated with other fields ; this type of reporting is caused by the inherent interconnections between phenomena from different disciplines. Plitvice Lakes, Croatia, are composed of a unique cascading chain of karst lakes, and these lakes have been investigated by numerous authors. Here, we provide an overview of the studies of the Plitvice Lakes Area (PLA) that address meteorology, climatology, hydrology, hydrogeochemistry and physical limnology. Our aim is to synthesize the results from each of these disciplines and make them available to scientists from other related disciplines ; thus, this review will facilitate further investigations of the PLA within the natural sciences. In addition, valuable results from early investigations of Plitvice Lakes are generally unavailable to the broader scientific community, and are written in Croatian. Here, we summarize these results and make them available to a wider audience.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43246991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It has been known for a while that there are two sites of wintertime dense water formation in the North Adriatic – one in the open sea and the other in the Croatian coastal sea. Recently, it has been established that dense water is transported between the two basins, with both directions of the transport being possible. Here, a simple two-box model is developed in order to interpret the finding. The model allows for surface heat loss from the two basins and for an advective exchange of heat between the basins. Explicit solution is obtained, not only for the original, nonlinear problem but also for a simplified, linearized problem, when the initial temperature difference between the two basins vanishes. Moreover, the effect of the initial temperature difference is explored with the linearized model. The solutions point to a continuous temperature decrease in the two basins, with the temperature differences tending to limiting values. The temporal variability is controlled by the initial temperature differences, surface heat fluxes and basin dimensions and it suggests that the sum of surface heat loss and advective heat gain in one basin tends to become equal to the sum of surface and advective heat losses in the other basin. The solutions also indicate that the sign of the temperature difference between the two basins could be positive or negative, implying that the cold, dense water could be transported either way. Finally, an index, incorporating the initial temperatures, the surface heat fluxes and the basin depths, is proposed with the aim of quantifying relative importance of the two North Adriatic sites of dense water formation for each particular winter.
{"title":"Exchange of dense water between the open North Adriatic and the Croatian coastal sea","authors":"M. Orlić","doi":"10.15233/GFZ.2018.35.11","DOIUrl":"https://doi.org/10.15233/GFZ.2018.35.11","url":null,"abstract":"It has been known for a while that there are two sites of wintertime dense water formation in the North Adriatic – one in the open sea and the other in the Croatian coastal sea. Recently, it has been established that dense water is transported between the two basins, with both directions of the transport being possible. Here, a simple two-box model is developed in order to interpret the finding. The model allows for surface heat loss from the two basins and for an advective exchange of heat between the basins. Explicit solution is obtained, not only for the original, nonlinear problem but also for a simplified, linearized problem, when the initial temperature difference between the two basins vanishes. Moreover, the effect of the initial temperature difference is explored with the linearized model. The solutions point to a continuous temperature decrease in the two basins, with the temperature differences tending to limiting values. The temporal variability is controlled by the initial temperature differences, surface heat fluxes and basin dimensions and it suggests that the sum of surface heat loss and advective heat gain in one basin tends to become equal to the sum of surface and advective heat losses in the other basin. The solutions also indicate that the sign of the temperature difference between the two basins could be positive or negative, implying that the cold, dense water could be transported either way. Finally, an index, incorporating the initial temperatures, the surface heat fluxes and the basin depths, is proposed with the aim of quantifying relative importance of the two North Adriatic sites of dense water formation for each particular winter.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43465189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In orientation and navigation using compass, reliable map’s marginal information of Earth’s magnetic field declination and its annual variation, namely geomagnetic information (GI), is crucial. Monitoring geomagnetic information means observing declination and its annual variation and checking the reliability of the actual GI model. A typical way of monitoring GI across a national territory involves conducting periodic geomagnetic network surveys to assess and update the model. The objective of the paper was to investigate improving the GI model reliability when an earlier model’s error was raised to standard accuracy, and repeat station network surveys were not yet completed. A series of processing steps in modelling were revised to preserve the original data reliability. The partial 2008.5, 2009.5 and 2010.5 declination solutions were directly reduced to epoch 2015.0, and then to 2016.0, using the IGRF-12 model. The next step was to use 2016 and 2017 quiet daily declination means to estimate corresponding annual variations at surrounding observatories and repeat stations. Normal declination annual variation models were then built for further reductions to epoch 2017.0, and 2018.0, and for forward extrapolations. The quiet days observatory data were analysed to estimate the effect of the input time series length and linear extrapolated time span on forward extrapolation error. Thus, the reliability decline of the initial GI model slowed down in the sequence of models presented. The final GI2018v2 model, valid for 2018.0–2019.0, proved reliable in comparison to the repeat station declination observations of 2018.
{"title":"Monitoring geomagnetic information in the territory of Croatia","authors":"M. Brkić","doi":"10.15233/GFZ.2019.36.3","DOIUrl":"https://doi.org/10.15233/GFZ.2019.36.3","url":null,"abstract":"In orientation and navigation using compass, reliable map’s marginal information of Earth’s magnetic field declination and its annual variation, namely geomagnetic information (GI), is crucial. Monitoring geomagnetic information means observing declination and its annual variation and checking the reliability of the actual GI model. A typical way of monitoring GI across a national territory involves conducting periodic geomagnetic network surveys to assess and update the model. The objective of the paper was to investigate improving the GI model reliability when an earlier model’s error was raised to standard accuracy, and repeat station network surveys were not yet completed. A series of processing steps in modelling were revised to preserve the original data reliability. The partial 2008.5, 2009.5 and 2010.5 declination solutions were directly reduced to epoch 2015.0, and then to 2016.0, using the IGRF-12 model. The next step was to use 2016 and 2017 quiet daily declination means to estimate corresponding annual variations at surrounding observatories and repeat stations. Normal declination annual variation models were then built for further reductions to epoch 2017.0, and 2018.0, and for forward extrapolations. The quiet days observatory data were analysed to estimate the effect of the input time series length and linear extrapolated time span on forward extrapolation error. Thus, the reliability decline of the initial GI model slowed down in the sequence of models presented. The final GI2018v2 model, valid for 2018.0–2019.0, proved reliable in comparison to the repeat station declination observations of 2018.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67353382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atmospheric pollution due to particulate matter in opencast coal mining area is a very important environmental problem and is fetching the attention of researchers worldwide since few decades. The particulate matter not only affects human but also have tremendous effects on nearby flora and fauna by degrading the ecological environment in many ways. High mechanization in mining operations leads to add heavy load of dust to the surrounding area. The adverse effects of dust depend on the quantity as well as the characteristics of the dust and the exposure dose. Taking the importance of the dust pollution in mines, a coal mine area of Talcher coalfield, was selected, which is one of the oldest coalfields of India and a very limited work has been carried out in that area on the regards of assessment of health risk due to metals on the local population. Monitoring of respirable dust (PM10 & PM2.5) were performed at eight monitoring stations around a high mechanised opencast coal mine for three seasons i.e., post monsoon, winter, and summer in the year 2015 as per the standard criteria of Central Pollution Control Board (CPCB), India. The seasonal variation of dust concentration was found in the order of winter > summer > post monsoon. Ten trace metals were analysed from the dust samples. Statistical analysis, such as, univariate (correlation study) and multi-variate analysis were carried out including principal component analysis (PCA) for source identification and respective contribution to particulate matter. Finally, the health risk in terms of hazards quotient (HQ) and hazards index (HI) were calculated for both children and adults for the three exposure path ways (Inhalation, ingestion and dermal exposure). The carcinogenic effects due to the presence of trace metals in the PM10 were evaluated for both children and adults in terms of excess cancer risk (ECR). The combined carcinogenic effects of all the trace metals also calculated (ECRtotal). The HQ values for Cr and Cd were found above the safe limit in that area for both children and adults. Likewise the ECR values for Cr and Cd also were at a very risk level for both the age group. However the risk related to other metals were found well within the safe limit. The HI and ECRtotal values were found above the safe limit which indicates the combined effect of trace metals on the children and adult were at and very high risk level in the study area.
{"title":"Measurement of respirable dust concentration and assessment of health risk due to metals around an opencast coal mine of Talcher, Odisha","authors":"Debi Prasad Tripathy, Tushar Ranjan Dash","doi":"10.15233/gfz.2019.36.2","DOIUrl":"https://doi.org/10.15233/gfz.2019.36.2","url":null,"abstract":"Atmospheric pollution due to particulate matter in opencast coal mining area is a very important environmental problem and is fetching the attention of researchers worldwide since few decades. The particulate matter not only affects human but also have tremendous effects on nearby flora and fauna by degrading the ecological environment in many ways. High mechanization in mining operations leads to add heavy load of dust to the surrounding area. The adverse effects of dust depend on the quantity as well as the characteristics of the dust and the exposure dose. Taking the importance of the dust pollution in mines, a coal mine area of Talcher coalfield, was selected, which is one of the oldest coalfields of India and a very limited work has been carried out in that area on the regards of assessment of health risk due to metals on the local population. Monitoring of respirable dust (PM10 & PM2.5) were performed at eight monitoring stations around a high mechanised opencast coal mine for three seasons i.e., post monsoon, winter, and summer in the year 2015 as per the standard criteria of Central Pollution Control Board (CPCB), India. The seasonal variation of dust concentration was found in the order of winter > summer > post monsoon. Ten trace metals were analysed from the dust samples. Statistical analysis, such as, univariate (correlation study) and multi-variate analysis were carried out including principal component analysis (PCA) for source identification and respective contribution to particulate matter. Finally, the health risk in terms of hazards quotient (HQ) and hazards index (HI) were calculated for both children and adults for the three exposure path ways (Inhalation, ingestion and dermal exposure). The carcinogenic effects due to the presence of trace metals in the PM10 were evaluated for both children and adults in terms of excess cancer risk (ECR). The combined carcinogenic effects of all the trace metals also calculated (ECRtotal). The HQ values for Cr and Cd were found above the safe limit in that area for both children and adults. Likewise the ECR values for Cr and Cd also were at a very risk level for both the age group. However the risk related to other metals were found well within the safe limit. The HI and ECRtotal values were found above the safe limit which indicates the combined effect of trace metals on the children and adult were at and very high risk level in the study area.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67353642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Western Anatolia has been shaped N–S-trending extensional tectonic regime and W-E trending horst, grabens and active faults due to the collision of Africa, Arabian and Eurasia plates. The borders of the Aegean Sea tectonic is limited between eastern of Greece, western of Anatolia and Hellenic subduction zone in the south of Crete. To evaluate these tectonic elements gravity disturbance data of the Aegean Sea and Western Anatolia was used in this study. It is thought that the gravity disturbance data reflects the tectonic elements and discontinuities way better than gravity anomaly due to the calculation from the difference between gravity and normal gravity at the same point so thus the tensors and invariants of the study area were calculated and the power spectrum method was applied to the gravity disturbance data. Various boundary analysis methods were applied to the gravity disturbance data to compare the discontinuities obtained from the tensors both theoretical and case study. These methods were tested initially on theoretical data. Within the scope of the theoretical study, a single model and three bodies model were taken into consideration. When the results are examined, it is observed that the Tzz tensor component gives very clear information about the location of the structure. Likewise, when the Txx, Tyy components and invariant results are examined, the vertical and horizontal boundaries were successfully obtained. In addition, the mean depths of these structures were determined using the power spectrum method. In the case application stage, the gravity disturbance data obtained from the Earth Gravitational Model of the eastern of the Aegean Sea and western of Anatolia were evaluated. The tensor and invariants of this gravity disturbance data were first calculated. New possible discontinuities have been identified in the tensors and some of the obtained discontinuities were clarified in their previous discussions. Also, the mean depths of the possible structures were calculated by the power spectrum method at four profiles taken from gravity disturbance data. These depth values are consistent with the depth values of the structural discontinuities obtained from previous studies. Finally, the upward continuation was applied to Tyy, Tyz and Tzz tensors up to 20 km. The positive anomaly values in Tyz and Tzz components and negative anomaly values in Tyy component are consistent with the Western Anatolia Transfer Zone. The structural differences between the eastern and the western of Western Anatolia are noteworthy in the upward continued results of the tensors. In addition, the positive and negative anomalies are notable in areas where the big earthquakes occurred in the last 3 years in the Tyz invariants.
{"title":"Analysis of gravity disturbance for boundary structures in the Aegean Sea and Western Anatolia","authors":"F. Doğru, O. Pamukçu","doi":"10.15233/GFZ.2019.36.5","DOIUrl":"https://doi.org/10.15233/GFZ.2019.36.5","url":null,"abstract":"Western Anatolia has been shaped N–S-trending extensional tectonic regime and W-E trending horst, grabens and active faults due to the collision of Africa, Arabian and Eurasia plates. The borders of the Aegean Sea tectonic is limited between eastern of Greece, western of Anatolia and Hellenic subduction zone in the south of Crete. To evaluate these tectonic elements gravity disturbance data of the Aegean Sea and Western Anatolia was used in this study. It is thought that the gravity disturbance data reflects the tectonic elements and discontinuities way better than gravity anomaly due to the calculation from the difference between gravity and normal gravity at the same point so thus the tensors and invariants of the study area were calculated and the power spectrum method was applied to the gravity disturbance data. Various boundary analysis methods were applied to the gravity disturbance data to compare the discontinuities obtained from the tensors both theoretical and case study. These methods were tested initially on theoretical data. Within the scope of the theoretical study, a single model and three bodies model were taken into consideration. When the results are examined, it is observed that the Tzz tensor component gives very clear information about the location of the structure. Likewise, when the Txx, Tyy components and invariant results are examined, the vertical and horizontal boundaries were successfully obtained. In addition, the mean depths of these structures were determined using the power spectrum method. In the case application stage, the gravity disturbance data obtained from the Earth Gravitational Model of the eastern of the Aegean Sea and western of Anatolia were evaluated. The tensor and invariants of this gravity disturbance data were first calculated. New possible discontinuities have been identified in the tensors and some of the obtained discontinuities were clarified in their previous discussions. Also, the mean depths of the possible structures were calculated by the power spectrum method at four profiles taken from gravity disturbance data. These depth values are consistent with the depth values of the structural discontinuities obtained from previous studies. Finally, the upward continuation was applied to Tyy, Tyz and Tzz tensors up to 20 km. The positive anomaly values in Tyz and Tzz components and negative anomaly values in Tyy component are consistent with the Western Anatolia Transfer Zone. The structural differences between the eastern and the western of Western Anatolia are noteworthy in the upward continued results of the tensors. In addition, the positive and negative anomalies are notable in areas where the big earthquakes occurred in the last 3 years in the Tyz invariants.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67354161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Kisi, C. Santos, R. M. Silva, M. Zounemat‐Kermani
Trend analysis of monthly mean streamflows is essential for better water resources management and planning. In this study, Mann Kendall (MK), Sen’s method and Şen’s innovative trend method (ITM) were employed in order to examine the possible trends of monthly streamflows obtained from nine stations from three basins (Yakabasi and Derecikviran in Western Black Sea Basin; Durucasu, Sütlüce, Kale and Gomeleonu in Yesilirmak Basin; Şimşirli, Tozköy and Topluca in Eastern Black Sea Basin) located in Black Sea Region of Turkey. Based on the MK, streamflow data of Tozköy Station which is located in western part of the Eastern Black Sea Region showed a significantly increasing trend while a significantly decreasing trend was found for the Yakabasi, Derecikviran, Durucasu and Sütlüce stations which are situated in western part of the Black Sea Region. According to the Sen’s trend method, a significantly decreasing trend was seen in Durucasu, Sütlüce, Yakabasi and Derecikviran stations while Tozköy station showed significantly increasing trend. According to the ITM, low-medium values of Tozköy Station indicated slightly increasing trend while low and medium streamflow values of Yakabasi, Derecikviran, Durucasu and Sütlüce stations showed a decreasing trend. High streamflow values of Derecikviran and Sütlüce stations showed a decreasing trend while corresponding values of Yakabasi, Şimşirli and Tozköy stations indicated an increasing trend. It was showed that trends of low, medium, and high data can be easily identified by ITM which has some advantages (having no assumption such as serial relationship, non-normality, and, test number) over the Sen’s method and Mann-Kendall test.
{"title":"Trend analysis of monthly streamflows using Şen's innovative trend method","authors":"O. Kisi, C. Santos, R. M. Silva, M. Zounemat‐Kermani","doi":"10.15233/GFZ.2018.35.3","DOIUrl":"https://doi.org/10.15233/GFZ.2018.35.3","url":null,"abstract":"Trend analysis of monthly mean streamflows is essential for better water resources management and planning. In this study, Mann Kendall (MK), Sen’s method and Şen’s innovative trend method (ITM) were employed in order to examine the possible trends of monthly streamflows obtained from nine stations from three basins (Yakabasi and Derecikviran in Western Black Sea Basin; Durucasu, Sütlüce, Kale and Gomeleonu in Yesilirmak Basin; Şimşirli, Tozköy and Topluca in Eastern Black Sea Basin) located in Black Sea Region of Turkey. Based on the MK, streamflow data of Tozköy Station which is located in western part of the Eastern Black Sea Region showed a significantly increasing trend while a significantly decreasing trend was found for the Yakabasi, Derecikviran, Durucasu and Sütlüce stations which are situated in western part of the Black Sea Region. According to the Sen’s trend method, a significantly decreasing trend was seen in Durucasu, Sütlüce, Yakabasi and Derecikviran stations while Tozköy station showed significantly increasing trend. According to the ITM, low-medium values of Tozköy Station indicated slightly increasing trend while low and medium streamflow values of Yakabasi, Derecikviran, Durucasu and Sütlüce stations showed a decreasing trend. High streamflow values of Derecikviran and Sütlüce stations showed a decreasing trend while corresponding values of Yakabasi, Şimşirli and Tozköy stations indicated an increasing trend. It was showed that trends of low, medium, and high data can be easily identified by ITM which has some advantages (having no assumption such as serial relationship, non-normality, and, test number) over the Sen’s method and Mann-Kendall test.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"35 1","pages":"53-68"},"PeriodicalIF":1.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.15233/GFZ.2018.35.3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67353355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The assessment of continentality and oceanity of the climate at a global level or within particular regions has lately gained in importance on the background of global warming and its impact on food and water resources. Aiming at understanding these influences, there were analysed the spatial distribution (based on the data from 27 meteorological stations) and temporal variability of four indices (for 19 meteorological stations with complete data series covering the interval 1961–2015). In specialized literature, there are used different continentality and oceanity indices. We studied four of them, but the results indicate that three of these are redundant, as they deliver almost the same information. Consequently, only the results based on Gorczyński Continentality Index (GCI) and Kerner Oceanity Index (KOI) are presented and discussed in greater detail. These indices emphasize the continental character of the climate in the region, except for a narrow strip along the Black Sea Coast, which displays a maritime climate. There did not emerge a clear intensification of continentality (the trends were not statistically significant), in spite of the increase of air temperature in the region during the last two decades. However, a good correlation was obtained between three of the analysed indices (GCI, II and KOI) and North Atlantic Oscillation Index (NAOI).
{"title":"Evaluation of thermal continentality within southern Romania and northern Bulgaria (1961-2015)","authors":"A. Vlăduţ, N. Nikolova, M. Licurici","doi":"10.15233/GFZ.2018.35.1","DOIUrl":"https://doi.org/10.15233/GFZ.2018.35.1","url":null,"abstract":"The assessment of continentality and oceanity of the climate at a global level or within particular regions has lately gained in importance on the background of global warming and its impact on food and water resources. Aiming at understanding these influences, there were analysed the spatial distribution (based on the data from 27 meteorological stations) and temporal variability of four indices (for 19 meteorological stations with complete data series covering the interval 1961–2015). In specialized literature, there are used different continentality and oceanity indices. We studied four of them, but the results indicate that three of these are redundant, as they deliver almost the same information. Consequently, only the results based on Gorczyński Continentality Index (GCI) and Kerner Oceanity Index (KOI) are presented and discussed in greater detail. These indices emphasize the continental character of the climate in the region, except for a narrow strip along the Black Sea Coast, which displays a maritime climate. There did not emerge a clear intensification of continentality (the trends were not statistically significant), in spite of the increase of air temperature in the region during the last two decades. However, a good correlation was obtained between three of the analysed indices (GCI, II and KOI) and North Atlantic Oscillation Index (NAOI).","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"35 1","pages":"1-18"},"PeriodicalIF":1.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47210375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Sridevi, Ashok Kumar, K. K. Singh, V. Durai, P. Suneetha
The Indian summer monsoon is one of the most important phenomenon that bring vital rain to India, so the Indian summer monsoon forecast and its verification is always of great interest due to monsoons' importance for India’s agriculture. In the present study the categorical (Yes / No) and quantitative verification of rainfall forecast of the Global Forecasting System model running at India Meteorological Department, IMD GFS T574 (25 km resolution) and National Centre for Environmental Prediction, NCEP GFS T1534 is done over Indian domain against 0.25° gridded rainfall observations during summer monsoon season 2015. A detailed verification study for rainfall forecast at 0.25° × 0.25° grid for Indian Window (0 – 40° N and 60 – 100° E) is conducted using two models output; both the / models are indicating that skill of the rainfall forecast is good for all parts of the country except high terrain regions. Regional verification also carried over 5 homogeneous regions of India, i.e., North India, West Coast India, North East India, Central India and Peninsular India using both model outputs. Results show that, in general, both the GFS T1534 and GFS T574 forecasts are skillful to capture climatologically heavy rainfall regions. However, the accuracy in prediction of location and magnitude of rainfall fluctuates considerably. The results documented are expected to be useful to the operational forecasters in day-to-day weather forecasting over Indian monsoon regions.
{"title":"Rainfall forecast skill of Global Forecasting System (GFS) model over India during summer monsoon 2015","authors":"C. Sridevi, Ashok Kumar, K. K. Singh, V. Durai, P. Suneetha","doi":"10.15233/GFZ.2018.35.4","DOIUrl":"https://doi.org/10.15233/GFZ.2018.35.4","url":null,"abstract":"The Indian summer monsoon is one of the most important phenomenon that bring vital rain to India, so the Indian summer monsoon forecast and its verification is always of great interest due to monsoons' importance for India’s agriculture. In the present study the categorical (Yes / No) and quantitative verification of rainfall forecast of the Global Forecasting System model running at India Meteorological Department, IMD GFS T574 (25 km resolution) and National Centre for Environmental Prediction, NCEP GFS T1534 is done over Indian domain against 0.25° gridded rainfall observations during summer monsoon season 2015. A detailed verification study for rainfall forecast at 0.25° × 0.25° grid for Indian Window (0 – 40° N and 60 – 100° E) is conducted using two models output; both the / models are indicating that skill of the rainfall forecast is good for all parts of the country except high terrain regions. Regional verification also carried over 5 homogeneous regions of India, i.e., North India, West Coast India, North East India, Central India and Peninsular India using both model outputs. Results show that, in general, both the GFS T1534 and GFS T574 forecasts are skillful to capture climatologically heavy rainfall regions. However, the accuracy in prediction of location and magnitude of rainfall fluctuates considerably. The results documented are expected to be useful to the operational forecasters in day-to-day weather forecasting over Indian monsoon regions.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"35 1","pages":"39-52"},"PeriodicalIF":1.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45427780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sebastian Kendzierski, B. Czernecki, Leszek Kolendowicz, A. Jaczewski
The article discusses the results of air temperature forecasts from four short-term and two long-term forecasts of numerical weather prediction models. The analysis covered the results of model simulations from January 2015 to January 2016 and compared them at 14 meteorological stations in Poland. The comparison was made based on the most commonly used measures for continuous parameters i.e., ME (mean error), MAE (mean absolute error), RMSE (root mean square error), MSE (mean square error), BIAS and Pearson correlation. In the short time horizon, the best results in the context of the MAE, RMSE, MSE and correlation values were obtained by the Unified Model, although the diagnosed differences between the models are small. All models in the 0–72 h projection horizon reached a correlation of 0.95–0.97 and an MAE in the range of 1.5 °C to 2.1 °C. In the case of long-term forecasts, the HIRLAM model was slightly better than the GFS model. Clearly, in both cases, there is a marked decrease in quality after the fourth and in the following forecast lead days.
{"title":"Air temperature forecasts' accuracy of selected short-term and long-term numerical weather prediction models over Poland","authors":"Sebastian Kendzierski, B. Czernecki, Leszek Kolendowicz, A. Jaczewski","doi":"10.15233/GFZ.2018.35.5","DOIUrl":"https://doi.org/10.15233/GFZ.2018.35.5","url":null,"abstract":"The article discusses the results of air temperature forecasts from four short-term and two long-term forecasts of numerical weather prediction models. The analysis covered the results of model simulations from January 2015 to January 2016 and compared them at 14 meteorological stations in Poland. The comparison was made based on the most commonly used measures for continuous parameters i.e., ME (mean error), MAE (mean absolute error), RMSE (root mean square error), MSE (mean square error), BIAS and Pearson correlation. In the short time horizon, the best results in the context of the MAE, RMSE, MSE and correlation values were obtained by the Unified Model, although the diagnosed differences between the models are small. All models in the 0–72 h projection horizon reached a correlation of 0.95–0.97 and an MAE in the range of 1.5 °C to 2.1 °C. In the case of long-term forecasts, the HIRLAM model was slightly better than the GFS model. Clearly, in both cases, there is a marked decrease in quality after the fourth and in the following forecast lead days.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"35 1","pages":"19-37"},"PeriodicalIF":1.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67353512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. T. Drakul, Mileva Samardžić Petrović, S. Grekulović, O. Odalović, D. Blagojević
This paper is dedicated to modeling extreme TEC (Total Electron Content) values at the territory of Serbia. For the extreme TEC values, we consider the maximum values from the peak of the 11-year cycle of solar activity in the years 2013, 2014 and 2015 for the days of the winter and summer solstice and autumnal and vernal equinox. The average TEC values between 10 and 12 UT (Universal Time) were treated. As the basic data for all processing, we used GNSS (Global Navigation Satellite System) observation obtained by three permanent stations located in the territory of Serbia. Those data, we accept as actual, i.e. as a “true TEC values”. The main objectives of this research were to examine the possibility to use two machine learning techniques: neural networks and support vector machine. In order to emphasize the quality of applied techniques, all results are adequately compared to the TEC values obtained by using International Reference Ionosphere global model. In addition, we separately analyzed the quality of techniques throughout temporal and spatial-temporal approach.
{"title":"Modelling extreme values of the total electron content: Case study of Serbia","authors":"M. T. Drakul, Mileva Samardžić Petrović, S. Grekulović, O. Odalović, D. Blagojević","doi":"10.15233/GFZ.2017.34.12","DOIUrl":"https://doi.org/10.15233/GFZ.2017.34.12","url":null,"abstract":"This paper is dedicated to modeling extreme TEC (Total Electron Content) values at the territory of Serbia. For the extreme TEC values, we consider the maximum values from the peak of the 11-year cycle of solar activity in the years 2013, 2014 and 2015 for the days of the winter and summer solstice and autumnal and vernal equinox. The average TEC values between 10 and 12 UT (Universal Time) were treated. As the basic data for all processing, we used GNSS (Global Navigation Satellite System) observation obtained by three permanent stations located in the territory of Serbia. Those data, we accept as actual, i.e. as a “true TEC values”. The main objectives of this research were to examine the possibility to use two machine learning techniques: neural networks and support vector machine. In order to emphasize the quality of applied techniques, all results are adequately compared to the TEC values obtained by using International Reference Ionosphere global model. In addition, we separately analyzed the quality of techniques throughout temporal and spatial-temporal approach.","PeriodicalId":50419,"journal":{"name":"Geofizika","volume":"34 1","pages":"297-314"},"PeriodicalIF":1.0,"publicationDate":"2017-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42509165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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