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QAR 데이터 분석을 통한 항공난류 조기 인지 가능성 연구
김인규,장조원 한국항공운항학회 2018 한국항공운항학회지 Vol.26 No.4
Although continuous passenger injuries and physical damages are repeated due to the unexpected aviation turbulence encountered during operations, there is still exist the limitation for preventing recurrence of similar events because the lack of real-time information and delay in technological developments regarding various operating conditions and variable weather phenomena. The purpose of this study is to compare and analyze the meteorological data of the aviation turbulence occurred and actual flight data extracted from the Quick Access Recorder(QAR) to provide some precursors that the pilot can identify aviation turbulence early by referring thru the flight instrumentation indications. The case applied for this study was recent event, a scheduled flight to Narita Airport ftom Korea that suddenly encountered turbulence during approach. According to the Korea Meteorological Administration(KMA)'s Weather data, it was observed that the strong amount of vorticity in the rear area of jet stream, which existed near Mount Fuji at that time. The QAR data analysis shows significant changes in the aircraft's parameters such as Pitch and Roll angle, Static Air Temperature(SAT), and wind speed and direction in tens of seconds to minutes before encounter the turbulence. If the accumulate reliability of the data in addition and verification of various parameters with continuous analysis of additional cases, it can be the precursors for the pilot's effective and pre-emptive action and conservative prevention measures against aviation turbulence to reduce subsequent passenger injuries in the aviation operations.
Han-Chang Ko,Hye-Yeong Chun 한국기상학회 2021 한국기상학회 학술대회 논문집 Vol.2021 No.10
One third power of the eddy dissipation rate (EDR), which is a primary aviation turbulence metric, is calculated based on the Thorpe method using high vertical-resolution radiosonde data (HVRRD) observed at operational stations in USA for 6 years (2012-2017), and the spatiotemporal variations of the HVRRD-derived EDR (HVRRD-EDR) are compared with those of in-situ flight EDR observed from commercial airlines. Comparisons are made in major flight routes over z=20-50 kft, using the flight-EDR observed in ±1 hour centered at 00 and 12 UTC and the HVRRD-EDR considering exclusively for clear-air turbulence. The occurrence number is the maximum at z=20-30 kft for HVRRD-EDR and at z=30-40 kft for flight-EDR, with a similar seasonal variations (largest in JJA and smallest in DJF). The ratio of light-or-greater (LOG) intensity turbulence events to the total turbulence events of HVRRD-EDR and flight-EDR also shows similar seasonal variations (largest in JJA and smallest in DJF). The moderate-or-greater (MOG) ratio of HVRRD-EDR is also the largest in JJA and smallest in DJF, but that of flight-EDR is the largest in MAM and smallest in SON. Vertically, the LOG ratio of HVRRD-EDR increases with height for all seasons, while that of flight-EDR is the largest at z=30-40 kft in JJA and at z=20-30 kft in other seasons decreasing with height. The MOG ratio of HVRRD-EDR is the largest at z=30-40 kft in DJF and at z=40-50 kft in other seasons, while that of flight-EDR is the largest at z=20-30 kft for all seasons.
강유정,최희욱,최유나,이상삼,황혜원,이혁제,이용희 한국항공운항학회 2023 한국항공운항학회지 Vol.31 No.3
Aviation turbulence, caused by atmospheric eddies, is a disruptive phenomenon that leads to abrupt aircraft movements during flight. To minimize the damages caused by such aviation turbulence, the Aviation Meteorological Office provides turbulence information through the Korea aviation Turbulence Guidance (KTG) and the Global-Korean aviation Turbulence Guidance (GKTG). In this study, we evaluated the performance of the KTG and GKTG models by comparing the in-situ EDR observation data and the generated aviation turbulence prediction data collected from the mid-level Korean Peninsula region from January 2019 to December 2021. Through objective validation, we confirmed the level of prediction performance and proposed improvement measures based on it. As a result of the improvements, the KTG model showed minimal difference in performance before and after the changes, while the GKTG model exhibited an increase of TSS after the improvements.
Kim, Soo‐,Hyun,Chun, Hye‐,Yeong John Wiley Sons, Ltd 2016 Meteorological applications Vol.23 No.4
<P><B>ABSTRACT</B></P><P>Using observational data from Korean Air Lines (KAL) Boeing (B) 737‐800, B777‐200 and B777‐300 flights from January to December 2012, the derived equivalent vertical gust velocity (DEVG) was calculated as a turbulence indicator. Based on 1 min flight segments using the calculated DEVG, the highest frequency of moderate‐or‐greater (MOG) turbulence occurred in the Northern Hemisphere winter, whereas the lowest frequency occurred in the Northern Hemisphere summer. Spatially, the KAL turbulence encounters (KAL‐DEVG) covered five regions, Asia, Oceania, Western Europe, North America and South America, following major flight routes. The number of observed turbulence events is normalized by flight density and navigation times. As a result, 1 MOG turbulence is observed <I>per</I> flight and <I>per</I> 10 h of navigation. Over East Asia, the observed MOG KAL‐DEVG mainly appeared to follow the jet stream and most turbulence events were related to shear instability and inertial instability. KAL‐DEVG was used to evaluate the operational Korean Aviation Turbulence Guidance (KTG) system developed using a combination of the Regional Data Assimilation and Prediction System (RDAPS) of the Korea Meteorological Administration and pilot reports over East Asia. The forecasting performance evaluated by the skill score (defined as the area under the curve based on the probability of detection statistics) on the operational‐KTG system against KAL‐DEVG and RDAPS analysis data was found to be 0.815, with 95% confidence levels ranging from 0.812 to 0.821. Using the RDAPS 6 and 12 h forecast data, the skill score was slightly less than 0.8 in comparison to KAL‐DEVG.</P>
기상청 현업 통합모델과 조종사기상보고 자료를 이용한 한국형 항공난류 예측시스템 개발
김정훈 ( Jung Hoon Kim ),전혜영 ( Hye Yeong Chun ) 한국항공운항학회 2012 한국항공운항학회지 Vol.20 No.4
Korean aviation Turbulenc Guidance (KTG) system is developed using the operational unified model (UM) of the Korea Meteorological Administration (KMA) and pilot reports (PIREPs) over East Asia. The KTG system comprised of twenty turbulence diagnostics that represent various turbulence potentials and have the best forecasting skills, which are combined into a single ensemble-averaged index, namely KTG, at upper-(above FL250) and mid-(below FL250) levels. It is found that the overall performance of the KTG is higher than those produced from the one single best index, and satisfies the minimum criteria (80% accuracy) that the system is operationally useful in aviation industry.
Soo-Hyun Kim,Jeonghoe Kim,Jung-Hoon Kim,Hye-Yeong Chun 한국기상학회 2021 한국기상학회 학술대회 논문집 Vol.2021 No.10
The cube root of the energy dissipation rate (EDR), as a standard reporting metric of atmospheric turbulence, is estimated using 1-Hz quick access recorder data from Korean-based national air carriers with two different types of aircraft (B737 and B777) in 2012. Various EDRs are estimated using zonal, meriodional, and derived vertical wind components, and derived equivalent vertical gust (DEVG). The wind-based EDRs are estimated by (i) second-order structure function, (ii) power spectral density (PSD), considering the Kolmogorov’s -5/3 dependence, and (iii) maximum-likelihood estimation using the von Kármán spectral model. The DEVG-based EDRs are estimated using (iv) lognormal mapping technique and (v) predefined parabolic relationship between observed DEVG and EDR. First, the second-order structure functions are computed for each wind component within defined inertial subrange. For methods (ii) and (iii), individual PSDs for each wind component are computed using the Fast Fourier Transform over a 2-minute time window. Using these five methods (three wind-based and two DEVG-based methods), the eleven EDR estimates are computed and their feasibility of turbulence detections is tested on three strong turbulence cases. It is found that the 1-Hz EDR estimates exhibit good agreement with selected strong turbulence cases, with respect to turbulence intensity and temporal patterns that are related to clear-air turbulence, mountain wave turbulence, and convectively induced turbulence, with diffferent characteristics of the observed EDRs.