Investigation of the relationship between aviation reports and instrumental observations for lightning incident in Marmara Region

Since the beginning of the 20th Century, in parallel with the development of technology and industry, aviation has become a mandatory requirement that state in accordance with these day's requirements. The last quarter of 20th Century and especially in the beginning of the 21st Century, it come to the fore as the preffered modes of transport by a lot of people. Firstly, aviation is the particular needs of military objectives in terms of defense, scout and attack in the previous period, then civil air transport located in the forefront of the modern world and people from many mass can use this mode of transportation mostly. Before starting to spread civil aviation, aviation was expensive modes of transportation, then in parallel with the increasing number of the aircraft number and the associated number of air transportation companies, now it offers the possibility to transport almost the same price with other types of transportation. Parallel to these developments in civil aviation, depending on the number of operations and an increasing number of passengers every year, many adversities has begun to be seen in this sector. Although air transport is the fastest and also taking part in one of the most reliable types of transport, many negativities seen in most types of transportation for many reasons are also reflected in air transport. The events that cause various disruptions and accidents in the airline can have a wide variety. In particular, some of the air transport problems originated from technical, pilotage, fire, security and weather conditions can cause huge financial losses and may lead to worse incidents such as accidents. The studies regarding this subject, in particular the cases causing disruptions and accidents in air transport are analyzed for years by many scientists and people involved in the sector. The conlusions and recommendations put forward in this studies related to aviation that require interdisciplinary studies, in this respect, with the impact of developing technologies helps in minimizing these problems. There is also a system that collected on a single network for all aviations activities such as incidents and accidents in the world in this regard, all activites have reported in this network and it can helps to aviations companies to be aware of each other. There is no doubt that weather conditions adverse effects in the airline transportation is quite large. In this regard, this study examined the impact of the one of the most important extreme weather events which is called lightning over many airports which are located in Marmara Region borders. Firstly, for 11 airports where located in Marmara Region (4 International and 7 National and Military Airports), Aviation Weather Routine Report (METAR) and Aviation Special Weather Report (SPECI), studying with in the 15-year period covering 01/01/2001 to 31/12/2015, and various statistical analyzes on a hourly, monthly and an yearly basis were made. In the second phase of the study, lightning flash data (ATDnet data) taken from Öztopal's study which titled "Determination of lightning climatology on Turkey", for the period of 01/01/2008 to 31/12/2014, is performed by making many statistical analysis in the same way. Because the main purpose of the study is reveal the relationship between the two types of observations that are observation reports based on human observations published by airport and instrumental observations by taken from Öztopal's study which titled "Determination of lightning climatology on Turkey", after analyzing the data among themselves, also to reveal their relationship each other are subjected to various methods of statistical analysis and comparison. Primarily, according to the analysis seen in all the world literature, the thresholds values that may be perceived to lightning in the human observations are researched, then in this context, all analyzes were conducted by determining the two different threshold values. For 2 selected threshold values, METAR-SPECI observations and Instrumental observations were compared each of them, and 2 most methods which are used to define the relationship between the rare events such as lightning and results and disclosed. In addition to these analyzes, using the various correlations between the 11 airport weather station's reports, with regard to the distance of the lightning events from each of them is also demonstrated in results. On the other hand, the hypothesis set out in the work that the relationship between the lightning seen near the sea and the inland areas have demonstrated using all airport aviation weather reports. In accordance with the information in world literature, the number of lightning events and frequency of its 10 times more common in the airports close to seaside than the airports located in landside. In this study, we are also expected to see that the airports near the seaside have more lightning events in selected period. The study also included analysis of the history of how the number of lightning flash occured for this period at 11 airports and near areas (12.5 km and 25 km range from center). Thus, at which time more intense and powerful lightning incident occured were determined in 15-year period. In another analysis type, using METAR and SPECI raports, thunderstorm events which were observed with lightning were analyzed. Then, all events are investigated seperately again for all airports that these events occured alone or with any type of precipitation. According to the analysis results obtained in the study, there is no good relationship between lightning incident detection based on instrumental observations and lightning incident detection based on human observations. Also this situation in some airports show very large differences. On the other hand, there is a better fit between the lightning seen within a radius of 12.5 km obtained from ATDnet data and METAR data then lightning seen within a radius of 25 km obtained from ATDnet data and METAR data. Lightning events was observed maximum at 21°C, and minimum at -5°C and at 35°C. The lowest number of lightning can be seen in these two extremes. Also, the thunderstorm which seen in the case of presence of lightning observed often largely with rain or alone. In direct with the hypothesis, considering the number of lightning occuring at airports according to their distance from the sea, the hypothesis could not be determined exactly which in areas close to the sea as mentioned that have greater number of lightning incidents for selected airports and periods. Otherwise, the opposite situation also is not true. Overall, especially for international airports with a high number of observations, in the determination of the lightning incident, transition to instrumental observations is necessary instead of human observations. In the medium and long term, the investments which made for instrumental observations will return as gains.