Use of MODIS and synthetic aperture radar wind speed imagery to describe the morphology of open cell convection

Young, George S.; Sikora, Todd D.; Fisher, Caren M

doi:10.5589/m07-044

Cited by 7 publications

(23 citation statements)

References 23 publications

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“…However, the closest NARR wind field occurs at 06:00:00 UTC, 25 min after the SAR image, and suggests that U 10 is about 3.1 m/s. The winds are clearly lower than those of Young et al [2007], which were in the range 10-12 m/s. NARR data also suggest that SST and the air temperature at 2 m height are about 4.5°C and 0.5°C, respectively.…”

Section: Meteorological Conditions With the Available Datamentioning

confidence: 87%

“…The couplets of updrafts and downdrafts result in the alternation of ocean surface roughness features on the scale of centimeters [Sikora et al, 1995;Ufermann and Romeiser, 1999;Sikora and Ufermann, 2004;Young et al, 2007]. Assuming dry convection, the occurrence of downward-moving, high-momentum airflow at the sea surface results in increased vertical shear in the near-surface horizontal wind.…”

Section: Imaging Atmospheric Convection In Sar Imagerymentioning

confidence: 99%

“…Increased wind shear provides enhanced momentum transfer to the sea surface via shear- driven surface layer turbulence. In an alternate view of things, Young et al [2007] and Sikora et al [2011] suggest that the signatures of open MCC are possibly tied to downdrafts fueled by evaporation, sublimation, or melting, which could constitute momentum mix-down in conjunction with precipitation. In any case, enhanced momentum transfer impacts the mean wind in the boundary layer and associated ocean waves.…”

Section: Imaging Atmospheric Convection In Sar Imagerymentioning

confidence: 99%

“…Young et al [2005] used SAR data to study the fine-scale processes associated with a synoptic-scale front at sea, including convection. In related studies, Moderate Resolution Imaging Spectroradiometer (MODIS) images, SAR-derived winds and marine variables estimated from MM5 (Pennsylvania State University/National Center for Atmospheric Research (NCAR) Mesoscale Model 5) were used to study open cellular convection in the Gulf of Alaska [Young et al, 2007]. Sikora et al [2011] presented an 8 year (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) climatology of the frequency of open cell convection over the northeast Pacific Ocean and the thermodynamic and kinematic environment associated with its development based on SAR-derived wind speed and reanalysis data.…”

Section: Introductionmentioning

confidence: 99%

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On polarimetric characteristics in SAR images of mesoscale cellular convection in the marine atmospheric boundary layer

Perrie

Guo

et al. 2011

J. Geophys. Res.

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Convection is an important phenomenon in the marine atmospheric boundary layer (MABL). Previous spaceborne radar studies of such have been limited to single polarization data, and therefore their focus was on the variation in intensity of the radar return, which was constrained by the existence of a single polarization image pattern, representing different atmospheric and oceanic phenomena. In this paper, we study the polarimetric characteristics of mesoscale cellular convection (MCC) in the MABL using high‐resolution data from fully polarimetric (HH, VV, HV, and VH) RADARSAT‐2 (RS‐2) synthetic aperture radar (SAR) images, in conjunction with closely collocated mesoscale atmospheric model simulations, to identify the MCC signatures. To compare the polarimetric characteristics of MCC with those of the ocean surface, our analysis also includes 641 open ocean surface quad‐polarization RS‐2 SAR images collocated with 52 National Data Buoy Center buoys. The open ocean surface SAR images exhibit different polarimetric characteristics from those of MCC. Thus, we differentiate MCC from other open ocean phenomena, based on identifiable polarimetric SAR characteristics.

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Section: Meteorological Conditions With the Available Datamentioning

confidence: 87%

Section: Imaging Atmospheric Convection In Sar Imagerymentioning

confidence: 99%

Section: Imaging Atmospheric Convection In Sar Imagerymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On polarimetric characteristics in SAR images of mesoscale cellular convection in the marine atmospheric boundary layer

Perrie

Guo

et al. 2011

J. Geophys. Res.

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“…1 and 2 in Sikora et al (2011) for examples of the SDWS and the Moderate Resolution Imaging Spectroradiometer (MODIS) true-color signature of open-cell convection, respectively. Sikora et al (2011) were motivated by an earlier case study, focused on the Gulf of Alaska (Young et al 2007), in which the connection between cold-pool dynamics and the organization of open-cell convection is hypothesized. That said, neither study employed precipitation data.…”

Section: Introductionmentioning

confidence: 99%

A Climatology of Precipitating Open-Cell Convection over the Northeast Gulf of Alaska

Sikora

Wendoloski

Marter

2014

Journal of Applied Meteorology and Climatology

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This brief paper addresses the frequency of precipitating open-cell convection over the northeastern Gulf of Alaska during a 5-yr period . The research employs 154 previously documented satellite synthetic aperture radar-derived wind speed (SDWS) images that contain open-cell convection signatures. Each SDWS image is paired with a near-in-time, National Weather Service Weather Surveillance Radar-1988 Doppler Level-III 0.58-elevation-angle short-range base reflectivity image from coastal Alaska for which coverage spatially overlaps open-cell convection signatures. The time difference between any two images of a single pair is typically a few minutes or less. For 65% of the image pairs, at least one SDWS open-cell convection signature in the overlap region is associated with precipitation. That percentage may be conservative given the method used in this research. Thus, the results of this research support a suggestion that has been posed in previous studies that the organization of open-cell convection can be controlled by the interaction of the environmental vertical wind shear and precipitation-driven cold pools.

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Oscillations in deep-open-cells during winter Mediterranean cyclones

et al. 2021

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Open cloud cells can be described in ideal form as connected clouds that surround spots of isolated clear skies in their centers. This cloud pattern is typically associated with marine stratocumulus (MSc) that form in the oceanic boundary layer. However, it can form in deeper convective clouds as well. Here, we focus on deep-open-cells (with tops reaching up to ~5–7 km) that form in the post-frontal regions of winter Mediterranean cyclones, and examine their properties and evolution. Using a Lagrangian analysis of satellite data, we show that deep-open-cells have a larger equivalent diameter (~58 ± 18 km) and oscillate with a longer periodicity (~3.5 ± 1 h) compared to shallow MSc. A numerical simulation of one Cyprus low event reveals that precipitation-generated convergence and divergence dynamic patterns are the main driver of the open cells’ organization and oscillations. Thus, our findings generalize the mechanism attributed to the behavior of shallow marine cells to deeper convective systems.

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Use of MODIS and synthetic aperture radar wind speed imagery to describe the morphology of open cell convection

Cited by 7 publications

References 23 publications

On polarimetric characteristics in SAR images of mesoscale cellular convection in the marine atmospheric boundary layer

On polarimetric characteristics in SAR images of mesoscale cellular convection in the marine atmospheric boundary layer

A Climatology of Precipitating Open-Cell Convection over the Northeast Gulf of Alaska

Oscillations in deep-open-cells during winter Mediterranean cyclones

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