Wintertime boundary-layer structure and air–sea interaction over the Japan/East Sea

Khelif, D.; Friehe, Carl A.; Jonsson, Haflidi H.; Wang, Qing; Rados, K.

doi:10.1016/j.dsr2.2004.04.005

Cited by 14 publications

(5 citation statements)

References 17 publications

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“…The results indicate that the mean value of the fluxes was independent of the averaging period, but the variance was largest when 1 km was used. The choice of 10 km is consistent with other studies (Khelif et al, 2005). This choice of 10 km averaging period gave a total of 592 segments over which flux estimates were performed.…”

Section: Measurements and Methodologysupporting

confidence: 67%

On the parameterization of turbulent fluxes over the tropical Eastern Pacific

Raga

Abarca

2007

Atmos. Chem. Phys.

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Abstract. We present estimates of turbulent fluxes of heat and momentum derived from low level (∼30 m) aircraft measurements over the tropical Eastern Pacific and provide empirical relationships that are valid under high wind speed conditions (up to 25 ms −1 ). The estimates of total momentum flux and turbulent kinetic energy can be represented very accurately (r 2 =0.99, when data are binned every 1 ms −1 ) by empirical fits with a linear and a cubic terms of the average horizontal wind speed. The latent heat flux shows a strong quadratic dependence on the horizontal wind speed and a linear relationship with the difference between the air specific humidity and the saturated specific humidity at the sea surface, explaining 96% of the variance. The estimated values were used to evaluate the performance of three currently used parameterizations of turbulence fluxes, varying in complexity and computational requirements. The comparisons with the two more complex parameterizations show good agreement between the observed and parameterized latent heat fluxes, with less agreement in the sensible heat fluxes, and one of them largely overestimating the momentum fluxes. A third, very simple parameterization shows a surprisingly good agreement of the sensible heat flux, while momentum fluxes are again overestimated and a poor agreement was observed for the latent heat flux (r 2 =0.62). The performance of all three parameterizations deteriorates significantly in the high wind speed regime (above 10-15 ms −1 ). The dataset obtained over the tropical Eastern Pacific allows us to derive empirical functions for the turbulent fluxes that are applicable from 1 to 25 ms −1 , which can be introduced in meteorological models under high wind conditions.

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Section: Measurements and Methodologysupporting

confidence: 67%

On the parameterization of turbulent fluxes over the tropical Eastern Pacific

Raga

Abarca

2007

Atmos. Chem. Phys.

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“…Probes mounted on a hard‐point ring near the gust probe on the nose include the UFT‐M, PVM, and three probes for measuring q v . This study relies in cloud‐free air on relatively slow rate q v data of several hertz from the University of California, Irvine (UCI)‐modified LI‐COR 7500 Lyman‐alpha probe [ Khelif et al ., ] since the fast cross‐flow UCI Lyman‐alpha probe failed early in the field program, and since the fast National Center for Atmospheric Research (NCAR) Lyman‐alpha probe produced noisy data. The gust probe consists of five holes leading to pressure transducers that produce after‐correction for aircraft motions ambient wind speed and wind fluctuations at a data rate of 40 Hz and 50 Hz [ Khelif et al ., ].…”

Section: Observationsmentioning

confidence: 99%

Entrainment rates and microphysics in POST stratocumulus

et al. 2013

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[1] An aircraft field study (POST; Physics of Stratocumulus Top) was conducted off the central California coast in July and August 2008 to deal with the known difficulty of measuring entrainment rates in the radiatively important stratocumulus (Sc) prevalent in that area. The Center for Interdisciplinary Remotely-Piloted Aircraft Studies Twin Otter research aircraft flew 15 quasi-Lagrangian flights in unbroken Sc and carried a full complement of probes including three high-data-rate probes: ultrafast temperature probe, particulate volume monitor probe, and gust probe. The probes' colocation near the nose of the Twin Otter permitted estimation of entrainment fluxes and rates with an in-cloud resolution of 1 m. Results include the following: Application of the conditional sampling variation of classical mixed layer theory for calculating the entrainment rate into cloud top for POST flights is shown to be inadequate for most of the Sc. Estimated rates resemble previous results after theory is modified to take into account both entrainment and evaporation at cloud top given the strong wind shear and mixing at cloud top. Entrainment rates show a tendency to decrease for large shear values, and the largest rates are for the smallest temperature jumps across the inversion. Measurements indirectly suggest that entrained parcels are primarily cooled by infrared flux divergence rather than cooling from droplet evaporation, while detrainment at cloud top causes droplet evaporation and cooling in the entrainment interface layer above cloud top.

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“…The North Korean Cold Current (NKCC) fl ows south along the Russian coast and the northern Korean Peninsula, intersecting the EKWC at the inception of the SPF (e.g., Huh and Shim, 1987). In winter, deep low-pressure systems draw cold dry Siberian air masses over the northern JES, forming cold dense waters that result in deep convective mixing (e.g., Talley et al, 2003, this issue;Dorman et al, 2004;Khelif et al, 2005;Lee et al, this issue). To the north of the SPF, the JES follows a distinct temperate-sub-polar seasonal cycle for water temperature and associated biological characteristics (e.g., primary production, copepod species, phytoplankton type) (Figure 3).…”

Section: A Unique Basinmentioning

confidence: 99%