Adana ve çevre illeri kapsayan havalimanlarında meydana gelen gök gürültülü fırtınaların zamansal ve mekansal analizi; 24 Aralık 2019 örnek olay çalışması
Temporal and spatial analysis of thunderstorms in airports covering Adana and surrounding provinces; 24 December 2019 case study
Yazar: ESRA DAŞDEMİR
Danışman: PROF. DR. ALİ DENİZ ; DOÇ. DR. EMRAH TUNCAY ÖZDEMİR
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Meteoroloji Mühendisliği Ana Bilim Dalı / Atmosfer Bilimleri Bilim Dalı
Derece: Yüksek Lisans, 2024
Konu: Meteoroloji = Meteorology

Özet:
Dünya çapında her yıl meydana gelen gök gürültülü fırtınalar meteorolojik hadiseler arasında önemli bir yere sahiptir. Gök gürültülü fırtınalar; dolu, yıldırım, kasırga, hortum gibi tehlikeli hava olaylarıyla ilişkili olduğundan can ve mal kayıplarına sebep olabilmektedir. Bu sebeple gök gürültülü fırtınalar uçuş güvenliği açısından da tehlike oluşturmaktadır. Türkiye'nin konumu ve topoğrafik yapısı gereği gök gürültülü sağanak yağışlar sıklıkla karşılaşılan meteorolojik olaylar arasındadır. Bu çalışmada Meteoroloji Genel Müdürlüğü (MGM) 'ne bağlı olan ve 6. Bölge Müdürlüğü olarak sınıflandırılan, Adana ve çevre illerde bulunan havalimanlarında meydana gelen gök gürültülü fırtınalar incelenmiştir. Bu havalimanları Adana Havalimanı (International Civil Aviation Organization [ICAO] kodu: LTAF), Adana İncirlik Hava Üssü (ICAO kodu: LTAG), Gaziantep Havalimanı (ICAO kodu: LTAJ), Hatay Havalimanı (ICAO kodu: LTDA)'dır. Bu çalışmada, MGM'den elde edilen 2009-2022 yılları arasını kapsayan meydan rutin hava raporu (Meteorological Terminal Airport Report [METAR]) verileri ve havacılık amaçlı seçilmiş özel hava raporu (Selected Aviation Special Weather Report [SPECI]) verileri kullanılarak gök gürültülü fırtına hadiseleri incelenerek bölgede şiddetli yağış, sel ve su baskınlarının yaşandığı gün olan 24 Aralık 2019 tarihi için analiz yapılmıştır. Belirlenen havalimanlarında en sık görülen hadise hafif şiddetteki gök gürültülü fırtına hadiseleri olurken, en az sayıda görülen ve etkisi en büyük olanlar ise şiddetli gök gürültülü fırtına hadiseleri olmuştur. Tüm gök gürültülü fırtına hadiseleri en çok ilkbahar (nisan, mayıs ayları) ve sonbahar (eylül, ekim ayları) mevsimlerinde, en az yaz (temmuz, ağustos) mevsiminde meydana gelmiştir. Yıldan yıla gözlenen fırtına sayısı artıp azalsa da, yıl bazında yalnızca Adana Havalimanı'nda artış eğilimi, diğer havalimanlarında ise azalma eğilimi olduğu tespit edilmiştir. Şiddetli fırtınalı günler belirlenmiş ve bu günlere ait belirli indeks değerleri ile hesaplanan rüzgâr kayması değerleri incelenmiştir. Konvektif kullanılabilir potansiyel enerji (Convective Available Potential Energy [CAPE]) ve rüzgâr kaymasının (Wind Shear [WS]) fırtına ile ilişkisi değerlendirilmiş ve rüzgâr kaymasının daha etkili olduğu sonucuna varılmıştır. 24 Aralık 2019 tarihinde başlayan, 34 saat devam eden yağış periyodunda İncirlik Meydan Meteoroloji Müdürlüğü'nde 315,8 kg yağış kaydedilmiştir. Meteoroloji 6. Bölge Müdürlüğü'nde ise kaydedilen toplam yağış miktarı 239,20'dir. Analizlerde sinoptik haritalar, uydu ve radar görüntüleri ve Skew-T Log-P diyagramları kullanılmıştır. Örnek olay çalışması için Adana'da meydana gelen gök gürültülü fırtına hadiselerinin, radar ve uydu verileri dikkate alınarak araştırılmış ve bölge üzerinden sağanak geçtiği, bu hat üzerinde çok hücreli gök gürültülü fırtınaların meydana geldiği sonucuna varılmıştır.

Abstract:
Thunderstorms occurring every year around the world are of great importance among meteorological events. Meteorological satellites in use today enable determining and tracking cloud formation phases, movement and development of active thunderstorms, frontal zones and cyclones.
Thunderstorms are primarily classified according to their intensity. Basically, storm cells are divided into two groups: single cell and supercell. Single-cell storms are short-lived and a few kilometers in diameter. Supercells consist of longer-lived and larger cells. Multicell storms can form from the combination of these two storm cells or simply in clusters of single-cell storms. Vertical wind shear formation and severe weather are less likely to occur in single-cell storms. On the other hand, multi-cell and supercell storms are visible in radar and satellite images, and the possibility of vertical wind shear and severe weather is quite high in these types of storms.
Storms have three basic phases according to their formation. The cumulus phase is the initial phase. Dry air near the ground begins to rise with the influence of external factors such as heating, topography or fronts. The rising air then continues to rise and condense until it reaches the Lifting Condensation Level (LCL), which determines the cloud base. In this way, as the moist air continues to rise, the storm cell expands horizontally and vertically. The clouds at this stage are cumulus clouds and generally many clouds cannot pass this stage. The cumulus stage transitions to the maturity stage with the formation of favorable conditions and cumulonimbus clouds are formed at this stage. During the maturity phase, weather events such as precipitation, thunder and lightning begin to occur. With the start of rain, particles moving downward fall into the unsaturated air and begin to evaporate, cooling the air. Thus, the downward current continues to strengthen and the upward current begins to weaken. Thus, the third phase, the disintegration phase, begins. The cumulonimbus begins to disappear and the storm cell gradually disappears. In multi-cell storms, this system can reach longer and more severe levels with the presence of vertical wind shear.
Thunderstorms are one of the major factors affecting flight activities. Since thunderstorms are associated with dangerous weather events such as hail, lightning, hurricane, and tornado, they can cause loss of life and property.Taking off and landing in stormy and heavy rainy weather is risky and dangerous due to wind shear and microburst formation as well as sudden changes in wind speed and direction. Therefore, observation, analysis and predictions become more important in order to be least affected by dangers. There are many different applications used for observations. Among these, ground observations are synoptic and climatological observations. Synoptic observations are used in weather forecasting. In ground observations, many parameters such as air temperature, wind direction, speed and movement, relative humidity, air pressure, current pressure, reduced pressure to sea level, current weather, visibility, cloud cover, and rainfall amount are measured. The obtained values are coded and reported and sent to national meteorology centers and from there to international collection centers. The information collected at the international center is redistributed to all countries. For high atmosphere observations, a radio transmitter observation device is sent to the upper level at certain stations. In addition, meteorological radars and satellites and automatic observation stations are used as data sources. Numerical weather forecast models are created using data to predict future weather events.

The instability index is a meteorological parameter used to assess the potential for atmospheric instability, which is a key factor in the development of thunderstorms. In meteorology, instability refers to the tendency of the atmosphere to enhance vertical motion and promote the development of convective storms. Several instability indices are used by meteorologists to quantify atmospheric instability. One commonly used index is the Convective Available Potential Energy (CAPE). CAPE measures the amount of energy available for upward vertical motion of air parcels. Higher CAPE values indicate greater potential for strong updrafts and the development of thunderstorms. 
The K Index is another meteorological parameter used to assess the potential for thunderstorm development. It is a measure of atmospheric instability, specifically focusing on the vertical temperature and moisture profile in the atmosphere. The K Index takes into account the difference between the temperature at two specific levels in the atmosphere, along with the dew point temperature. High K Index values suggest a greater potential for strong updrafts, convective activity, and the formation of thunderstorms. As with other instability indices, the K Index is often used in combination with other factors, such as wind shear and moisture content, to provide a more comprehensive understanding of the atmospheric environment and the potential for severe weather. 
The Lifted Index (LI) is another meteorological parameter used to assess atmospheric instability and its relation to thunderstorm development. Specifically, the Lifted Index measures the temperature difference between a parcel of air lifted from the surface to a certain level in the atmosphere and the surrounding environment at that level. It provides valuable information about the vertical stability of the atmosphere and the conditions conducive to convective activity.
In the context of thunderstorms, the instability index helps meteorologists assess the likelihood and intensity of convective activity. When warm, moist air near the surface is overlaid by cooler air aloft, creating an unstable atmosphere, it becomes conducive to the rapid ascent of air parcels, leading to the formation of thunderstorms. The greater the instability index, the more favorable the conditions for convective storms.

Meteorologists often use instability indices in conjunction with other atmospheric parameters, such as wind shear and moisture content, to better understand and predict thunderstorm development and severity. High instability, combined with favorable wind and moisture conditions, increases the likelihood of severe thunderstorms with characteristics like large hail, damaging winds, and tornadoes.
Due to location and topographic structure of Turkey, thunderstorms are among the frequently encountered meteorological events. In this study, thunderstorms occurring at the airports in Adana Regional Directorate -classified as the 6th Regional Directorate- affiliated with Turkish State Meteorological Service (TSMS)  were examined. These airports are Adana Airport (International Civil Aviation Organization [ICAO] code: LTAF), Adana Incirlik Air Base (ICAO code: LTAG), Gaziantep Airport (ICAO code: LTAJ), Hatay Airport (ICAO code: LTDA). In this study, obtained from TSMS covering the period 2009-2022; storm events were examined using Meteorology Terminal Airport Report (METAR) data and Selected Aviation Special Weather Report (SPECI) data selected for aviation purposes. In the part of these reports coded as current weather, thunderstorms with rain, thunderstorms with hail and rain, and thunderstorms without rain were examined according to their intensity. In addition, analysis was made for December 24, 2019, the day when heavy rain and floods occurred in the region. The most common event at the specified airports was light thunderstorm events, while the least frequent and most impactful events were heavy thunderstorm events. All thunderstorm events occurred most in the spring (April, May) and autumn (September, October) seasons, and least in the summer (July, August). Although the number of storms observed increases and decreases from year to year, it has been determined that there is an increasing trend only in Adana Airport and a decreasing trend in other airports over the years. It can be said that Seyhan Lake, located to the north of Adana Airport, will encounter more frequent weather conditions suitable for storm formation as a result of the instability caused by the heat and moisture gain.
The days when severe thunderstorms occurred at each airport were determined. The index values at the hours closest to these days were examined and the wind drift and lapse rate values between 0 - 6 km were calculated. In addition, days when severe storms occur simultaneously at airports have been determined. 
The relationship between CAPE and wind shear and the storm was evaluated and compared with studies in the literature. It was concluded that wind shear is more effective than CAPE values.During the 34-hour rainfall period that started on December 24, 2019, 315.8 kg of rainfall was recorded at Incirlik Air Base Meteorology Office. The total amount of precipitation recorded in the 6th Regional Directorate of Meteorology is 239.20. In the analysis, synoptic maps, satellite and radar images, Skew-T Log-P diagrams and meteorological observation data were used. This long-term rainfall, which negatively affects the city and life, has been examined in detail at micro, macro and meso scales. In the synoptic analysis, it was observed that the presence of a cold front at ground level and the development of a cyclone due to the low center in the upper atmosphere and turning into a trough on the Mediterranean coasts caused squal line formation, which caused long-term precipitation. In radar analysis, it was observed that the wind speed reached 50 knots at 3 to 5 km. In the Skew-t LogP diagram, it was seen that the wind speed in the upper atmosphere reached up to 100 knots.
As a result, the heavy rain events occurring in Adana were examined by taking into account the meteorological parameters and it was concluded that heavy rains passed through the region for the case study and multicell thunderstorms occurred on this line for the case study.