Retrieval of eddy dissipation rate from derived equivalent vertical gust included in Aircraft Meteorological Data Relay (AMDAR)

Kim, Soo Hyun; Chun, Hye‐Yeong; Sharman, Robert; Strahan, Matt

doi:10.5194/amt-13-1373-2020

Cited by 18 publications

(44 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As mentioned above, some lower bins (open circles) were not included to obtain the optimal fit. In other words, only bins with a higher SW (filled circles) were used to construct the best lognormal PDF fit [3,27,51,52]. The histogram of the SW data agreed with a lognormal distribution, implying that the SW data accurately reflected the nature of turbulence, which is random and chaotic in the atmosphere.…”

Section: Methodology For Edr Conversionmentioning

confidence: 83%

“…To use this statistical mapping equation to obtain the radar SW-derived EDR, the turbulence diagnostic D was replaced by the observed radar SW data. This approach is applicable for other properties related to turbulence like derived vertical gust [52]. Therefore, Equation (3) can be written as:…”

Section: Methodology For Edr Conversionmentioning

confidence: 99%

“…To obtain the mean and SD of a natural logarithm of SW [ln(SW)], the probability density function (PDF) of the SW must be calculated. The best lognormal PDF fit function to the histogram of the observed SW can be calculated using the Powell's method [3,27,51,52], which minimizes the root mean square error (RMSE) between the observed histograms and lognormal PDF fit. The lognormal PDF fit process is briefly described as follows: First, 50 bins for the entire range (x) of the SW are set to construct the histogram in the log-scale domain, and the mean and SD of the histogram are obtained.…”

Section: Methodology For Edr Conversionmentioning

confidence: 99%

“…Third, the lognormal fit is optimized by applying Powell's method with multiple candidates of µ and σ around the first guess from the histogram [3,27,51,52]. Here, we were interested in larger values of SW, which are responsible for stronger turbulence, so we focused on the range of the PDF fitting on the right side of the histogram [3,27,51,52]. Finally, the best lognormal PDF fitting function was obtained within the defined range of the observed SW.…”

Section: Methodology For Edr Conversionmentioning

confidence: 99%

“…Remote Sens. 2021, 13, x FOR PEER REVIEW 9 of were interested in larger values of SW, which are responsible for stronger turbulence, we focused on the range of the PDF fitting on the right side of the histogram [3,27,51,52 Finally, the best lognormal PDF fitting function was obtained within the defined range the observed SW. Figure 7 shows the observed histogram (dots) and the derived best lognormal PD fit (red line) using the radar SW data below the z = 8 km level from 04:50 UTC to 05:5 UTC on 28 October 2018.…”

Section: Methodology For Edr Conversionmentioning

confidence: 99%

See 4 more Smart Citations

A Detection of Convectively Induced Turbulence Using in Situ Aircraft and Radar Spectral Width Data

et al. 2021

Self Cite

View full text Add to dashboard Cite

A commercial aircraft, departing from Seoul to Jeju Island in South Korea, encountered a convectively induced turbulence (CIT) at about z = 2.2 km near Seoul on 28 October 2018. At this time, the observed radar reflectivity showed that the convective band with cloud tops of z = 6–7 km passed the CIT region with high values of spectral width (SW; larger than 4 m s–1). Using the 1 Hz wind data recorded by the aircraft, we estimated an objective intensity of the CIT as a cube root of eddy dissipation rate (EDR) based on the inertial range technique, which was about 0.33–0.37 m2/3 s-1. Radar-based EDR was also derived by lognormal mapping technique (LMT), showing that the EDR was about 0.3–0.35 m2/3 s-1 near the CIT location, which is consistent with in situ EDR. In addition, a feasibility of the CIT forecast was tested using the weather and research forecast (WRF) model with a 3 km horizontal grid spacing. The model accurately reproduced the convective band passing the CIT event with an hour delay, which allows the use of two methods to calculate EDR: The first is using both the sub-grid and resolved turbulent kinetic energy to infer the EDR; the second is using the LMT for converting absolute vertical velocity (and its combination with the Richardson number) to EDR-scale. As a result, we found that the model-based EDRs were about 0.3–0.4 m2/3 s-1 near the CIT event, which is consistent with the estimated EDRs from both aircraft and radar observations.

show abstract

Section: Methodology For Edr Conversionmentioning

confidence: 83%

Section: Methodology For Edr Conversionmentioning

confidence: 99%

Section: Methodology For Edr Conversionmentioning

confidence: 99%

Section: Methodology For Edr Conversionmentioning

confidence: 99%

Section: Methodology For Edr Conversionmentioning

confidence: 99%

See 3 more Smart Citations

A Detection of Convectively Induced Turbulence Using in Situ Aircraft and Radar Spectral Width Data

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Aircraft observations and reanalysis depictions of trends in the North Atlantic winter jet stream wind speeds and turbulence

Tenenbaum

Williams

Turp

et al. 2022

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

Multiple studies have considered whether increased anthropogenic CO2 will affect the wind speeds and turbulence associated with the winter North Atlantic polar‐front jet stream in the upper atmosphere. Key questions are whether any effects can already be seen and, if so, can they be seen independent of computer models of the atmosphere. In this study we use two reanalyses, NCEP/NCAR and the ECMWF ERA5, and two large observational archives, AMDAR/ACARS and the Global Aircraft Data Set (GADS), to try to answer these questions for the period 2002–2020 when automated aircraft observations were plentiful over the North Atlantic. We focus on eastbound, New York to London, flights. No significant increase appears in reanalyses during the last roughly 40 years (1979–2020) which is our best estimate for the modern satellite era. In contrast, for the last roughly 20 years (2002–2020) both the ERA5 reanalysis (2.5% per year) and the GADS archive (1.2% to 1.4% per year) show a statistically significant rise in the wind speed in the North Atlantic jet streak exit region. These results must be considered in the context of atmospheric oscillations, changes to the North Atlantic Track System (NATS), and the effects of aircraft step climbs. We estimate that up to 0.5% of the rise may be due to improvements in the NATS operations and an unknown additional amount may be due to the substantial increase in automated aircraft observations starting in 1997. We also examine the impact of aircraft observations on one's confidence in drawing conclusions from secular changes in the reanalyses. For turbulence, the Light turbulence trends are not statistically significant. Our confidence in the turbulence results is more limited since these observations reflect medium‐term changes in tactical and strategic aircraft operational procedures as well as the underlying prevalence of turbulence.

show abstract

An 11-year analysis of in situ records of aviation-scale turbulence over Europe

Gerogiannis

Feidas

2021

Theor Appl Climatol

View full text Add to dashboard Cite

Retrieval of eddy dissipation rate from derived equivalent vertical gust included in Aircraft Meteorological Data Relay (AMDAR)

Cited by 18 publications

References 29 publications

A Detection of Convectively Induced Turbulence Using in Situ Aircraft and Radar Spectral Width Data

A Detection of Convectively Induced Turbulence Using in Situ Aircraft and Radar Spectral Width Data

Aircraft observations and reanalysis depictions of trends in the North Atlantic winter jet stream wind speeds and turbulence

An 11-year analysis of in situ records of aviation-scale turbulence over Europe

Contact Info

Product

Resources

About