LEE- Atmosfer Bilimleri-Yüksek Lisans

Bu koleksiyon için kalıcı URI

http://hdl.handle.net/11527/19193

Gözat

Yazar "Demirhan, Deniz" ile LEE- Atmosfer Bilimleri-Yüksek Lisans'a göz atma
  • Öge
    Fog analysis for Antalya International Airport
    (Graduate School, 2025-01-22) Keskin, Muhammed ; Demirhan, Deniz ; 511201020 ; Atmospheric Science
    Fog represents one of the most challenging meteorological phenomena affecting air transportation, exerting considerable influence on flight safety, operational efficiency, and overall passenger experience. Reduced visibility during fog events can lead to flight delays, cancellations, diversions, and, in extreme cases, serious accidents. The resulting financial losses for airlines, coupled with the inconveniences and time delays imposed on passengers, highlight the critical importance of understanding and managing fog occurrences at airports. Although coastal regions often experience frequent and dense fog, Antalya International Airport, situated on the Mediterranean coast of Türkiye, presents a notable deviation from this pattern. The rarity of fog events at this seaside location offers a unique opportunity to investigate the underlying meteorological and microclimatic dynamics that influence fog formation. This thesis provides a comprehensive analysis of fog events recorded at Antalya International Airport between 2001 and 2022. Utilizing a rich dataset derived from Aviation Routine Weather Reports (METAR) and Aviation Selected Special Weather Reports (SPECI), this study examines the frequency, timing, and characteristics of fog occurrences on annual, seasonal, monthly, and hourly scales. Special attention is given to visibility trends and the interplay between regional climatic conditions, particularly wind speed and direction, temperature, and humidity patterns, that collectively govern the onset and dissipation of fog. The results reveal that despite Antalya's coastal setting, the number of fog events is remarkably low, totaling only 11 occurrences over the 22-year study period. Seasonal analysis indicates that fog is most frequently observed in the spring season, with the highest concentrations recorded in April. Furthermore, fog typically forms during the early morning hours, often between midnight and 5 AM, when radiative cooling leads to surface temperature declines and heightened relative humidity levels conducive to condensation. These findings correlate with established meteorological principles that link nocturnal cooling and reduced turbulence to increased fog likelihood. An in-depth examination of visibility conditions during fog events shows that while visibility commonly falls below 1,000 meters, a substantial proportion of fog occurrences maintain visibility levels around 800 meters, allowing the continued use of Instrument Landing Systems (ILS). This moderate reduction in visibility helps mitigate some operational challenges, though flight delays and route adjustments may still be necessary. Wind rose analyses further indicate that fog events are strongly associated with weak northerly winds at speeds generally below 4 m/s. Such calm atmospheric conditions hinder the dispersion of moisture-laden air near the surface, favoring fog formation. By focusing on the unusual infrequency of fog at Antalya International Airport, this research offers valuable insights into the local microclimatic conditions that shape fog dynamics. The interplay between coastal geography, prevailing wind patterns, and the thermal properties of land and sea surfaces emerges as a key driver of the observed patterns. Understanding these factors is essential for air traffic management, as improved forecasting and operational planning can enhance flight safety, reduce delays, and lower economic costs. In conclusion, this study provides a detailed characterization of fog phenomena at Antalya International Airport, illustrating the importance of site-specific meteorological analyses. The findings contribute to the broader knowledge base on fog formation and dispersion processes, potentially guiding the development of more effective operational strategies and advanced forecasting tools at Antalya and other airports with similarly distinctive climatic conditions.
  • Öge
    Variability of takeoff distance and climate rate due to climate factors
    (Graduate School, 2024) Çağlıyan Yalçınkaya, Şeyda ; Demirhan, Deniz ; 511201042 ; Atmospheric Science
    Climate change, resulted from increased fossil fuel combustion after the Industrial Revolution, has triggered a persistent global warming trend. Rapidly increasing global temperatures have a significant impact on the aviation industry, and a comprehensive understanding of their impacts is required to ensure the safety and efficiency of future flight operations. As a result of rapidly increasing global temperatures, aircraft performance during takeoff is considerably endangered, affecting important measurements such as weight considerations and fuel consumption, which are especially important at airports with shorter runways or higher altitudes. The interaction between rising temperatures and lower air density amplifies the challenge of generating sufficient lift force for aircraft taking off in less dense air. These adverse conditions greatly affect prominent parameters that determine takeoff performance, including takeoff distance and climb rate. As temperatures soar and pressure altitudes alter, the future forecast for aviation operations is determined by increased takeoff distances and descended climb rates. This comprehensive study scrutinizes the impact of climate change on takeoff distance and climb rates across ten prominent Turkish airports. The findings reveal a very clear fact: there are significant air temperature increases as well as different changes in pressure altitudes between these airports. Projections emphasize inevitable heightened takeoff distances and descended climb rates, all stemming from the anticipated elevation in temperatures and pressure altitudes. Examining distinct time frames 1980-2010 (past), 2023-2053 (near future), and 2069-2099 (far future) during the summer months reveals a changing trend. Anticipated average takeoff distance increments by 1-3% from 1980-2010 to 2023-2053 and leaps by 4-7% from 2023-2053 to 2069-2099. Conversely, average climb rates are anticipated to decline by 1-2% from 1980-2010 to 2023-2053 and descent by 3-5% from 2023-2053 to 2069-2099. Furthermore, these insights underline a critical necessity: the aviation industry must proactively devise adaptive strategies and technological advancements to alleviate the projected impacts of climate change on flight operations. The significant correlations between rising temperatures, fluctuating pressure altitudes, and the intricate dynamics of flight highlight the urgent need for ongoing research and innovative solutions within the aviation sector. Determining these challenges becomes crucial not only for operational safety but also for encouraging sustainable aviation practices that overcome the challenges that emerge from climate change.