Characterization of Uncertainty in Measurements of Wind from the NSF/NCAR Gulfstream V Research Aircraft

Cooper, Andrew B.; Friesen, B.; Hayman, Matthew; Jensen, J. B.; Lenschow, H.; Romashkin, P. A.; Schanot, Allen; Spuler, Scott M.; Stith, Jeffrey L.; Wolff, Cory A.

doi:10.5065/d60g3hj8

Cited by 2 publications

(2 citation statements)

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“…Observing Laboratory 2015a) are used to estimate the wave energy and momentum fluxes along the flight path, see Smith et al (2016) and Cooper et al (2016) for the specifications of the accuracy of the measured quantities UIC, VIC, WIC, WSC, WDC, ATX, and THETA, representing the velocity components , , , the horizontal wind speed V H and wind direction H , and the potential temperature Θ.…”

Section: Datamentioning

confidence: 99%

Stratospheric Gravity Waves Excited by a Propagating Rossby Wave Train—A DEEPWAVE Case Study

Eckermann

Williams

Haggerty

2022

Journal of the Atmospheric Sciences

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Stratospheric gravity waves observed during the DEEPWAVE research flight RF25 over the Southern Ocean are analyzed and compared with numerical weather prediction (NWP) model results. The quantitative agreement of the NWP model output and the tropospheric and lower stratospheric observations is remarkable. The high-resolution NWP models are even able to reproduce qualitatively the observed upper stratospheric gravity waves detected by an airborne Rayleigh lidar. The usage of high-resolution ERA5 data – partially capturing the long internal gravity waves – enabled a thorough interpretation of the particular event. Here, the observed and modeled gravity waves are excited by the stratospheric flow past a deep tropopause depression belonging to an eastward propagating Rossby wave train. In the reference frame of the propagating Rossby wave, vertically propagating hydrostatic gravity waves appear stationary; in reality, of course, they are transient and propagate horizontally at the phase speed of the Rossby wave. The subsequent refraction of these transient gravity waves into the polar night jet explains their observed and modeled patchy stratospheric occurrence near 60°S. The combination of both unique airborne observations and high-resolution NWP output provides evidence for the one case investigated in this paper. As the excitation of such gravity waves persists during the quasi-linear propagation phase of the Rossby wave’s life cycle, a hypothesis is formulated that parts of the stratospheric gravity wave belt over the Southern Ocean might be generated by such Rossbywaves trains propagating along the mid-latitude wave guide.

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Section: Datamentioning

confidence: 99%

Stratospheric Gravity Waves Excited by a Propagating Rossby Wave Train—A DEEPWAVE Case Study

Eckermann

Williams

Haggerty

2022

Journal of the Atmospheric Sciences

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“…Although recent attempts with airborne measurements to measure vertical velocity in the fair-weather atmosphere have been somewhat successful (e.g. De Wekker et al 2012;Cooper et al 2016), the expected magnitude of synoptic-scale subsidence in the SJV is several factors smaller than what has been demonstrated in those studies. With a lack of methodology to directly measure W zi , we instead rely on the WRF model described in Sect.…”

Section: Entrainment Velocity and Boundary Layer Heightmentioning

confidence: 93%

Entrainment Rates and Their Synoptic Dependence on Wind Speed Aloft in California's Central Valley

Caputi

Trousdell

Mehrotra

et al. 2022

Boundary-Layer Meteorol

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Daytime atmospheric boundary layer (ABL) dynamics—including potential temperature budgets, water vapour budgets, and entrainment rates—are presented from in situ flight data taken on six afternoons near Fresno in the San Joaquin Valley (SJV) of California during July/August 2016. The flights took place as a part of the California Baseline Ozone Transport Study aimed at investigating transport pathways of air entering the Central Valley from offshore and mixing down to the surface. Midday entrainment velocity estimates ranged from 0.8 to 5.4 cm s−1 and were derived from a combination of continuously determined ABL heights during each flight and model-derived subsidence rates, which averaged -2.0 cm s−1 in the flight region. A strong correlation was found between entrainment velocity (normalized by the convective velocity scale) and an inverse bulk ABL Richardson number, suggesting that wind shear at the ABL top plays a significant role in driving entrainment. Similarly, we found a strong correlation between the entrainment efficiency (the ratio of entrainment to surface heat fluxes with an average of 0.23 ± 0.15) and the wind speed at the ABL top. We explore the synoptic conditions that generate higher winds near the ABL top and propose that warm anomalies in the southern Sierra Nevada mountains promote increased entrainment. Additionally, a method is outlined to estimate turbulence kinetic energy, convective velocity scale (w*), and the surface sensible heat flux in the ABL from a slow, airborne wind measurement system using mixed-layer similarity theory.

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Characterization of Uncertainty in Measurements of Wind from the NSF/NCAR Gulfstream V Research Aircraft

Cited by 2 publications

References 0 publications

Stratospheric Gravity Waves Excited by a Propagating Rossby Wave Train—A DEEPWAVE Case Study

Stratospheric Gravity Waves Excited by a Propagating Rossby Wave Train—A DEEPWAVE Case Study

Entrainment Rates and Their Synoptic Dependence on Wind Speed Aloft in California's Central Valley

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