scholarly journals The effect of a regional increase in ocean surface roughness on the tropospheric circulation: a GCM experiment

1993 ◽  
Vol 8 (6) ◽  
pp. 277-285 ◽  
Author(s):  
Uwe Ulbrich ◽  
Gerd Bürger ◽  
Dierk Schriever ◽  
Hans von Storch ◽  
Susanne L Weber ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ocean Surface ◽  
Tropospheric Circulation

Anatomy of the Ocean Surface Roughness

2002 ◽  
Author(s):  
Paul A. Hwang ◽  
David W. Wang ◽  
William J. Teague ◽  
Gregg A. Jacobs ◽  
Joel Wesson
Keyword(s):  
Surface Roughness ◽  
Ocean Surface

scholarly journals Whitecap Observations by Microwave Radiometers: With Discussion on Surface Roughness and Foam Contributions

2020 ◽  
Vol 12 (14) ◽  
pp. 2277
Author(s):  
Paul A. Hwang
Keyword(s):  
Surface Roughness ◽  
Dielectric Properties ◽  
Surface Wave ◽  
Wave Breaking ◽  
Microwave Radiometer ◽  
Video Recording ◽  
Ocean Surface ◽  
Optical Observations ◽  
Microwave Signals ◽  
Microwave Radiometers

Ocean surface whitecaps manifest surface wave breaking. Most of the whitecap data reported in the literature are based on optical observations through photographic or video recording. The air in whitecaps modifies the dielectric properties of microwave emissions and scattering. Therefore, whitecap information is intrinsic to microwave signals. This paper discusses a method to retrieve the ocean surface whitecap coverage from microwave radiometer signals.

scholarly journals Ocean Surface Roughness Spectrum in High Wind Condition for Microwave Backscatter and Emission Computations*

2013 ◽  
Vol 30 (9) ◽  
pp. 2168-2188 ◽  
Author(s):  
Paul A. Hwang ◽  
Derek M. Burrage ◽  
David W. Wang ◽  
Joel C. Wesson
Keyword(s):  
Remote Sensing ◽  
Surface Roughness ◽  
Surface Waves ◽  
Microwave Remote Sensing ◽  
Ocean Surface ◽  
Short Wave ◽  
Wind Condition ◽  
Bragg Resonance ◽  
High Wind ◽  
Radar Backscatter

Abstract Ocean surface roughness plays an important role in air–sea interaction and ocean remote sensing. Its primary contribution is from surface waves much shorter than the energetic wave components near the peak of the wave energy spectrum. Field measurements of short-scale waves are scarce. In contrast, microwave remote sensing has produced a large volume of data useful for short-wave investigation. Particularly, Bragg resonance is the primary mechanism of radar backscatter from the ocean surface and the radar serves as a spectrometer of short surface waves. The roughness spectra inverted from radar backscatter measurements expand the short-wave database to high wind conditions in which in situ sensors do not function well. Using scatterometer geophysical model functions for L-, C-, and Ku-band microwave frequencies, the inverted roughness spectra, covering Bragg resonance wavelengths from 0.012 to 0.20 m, show a convergent trend in high winds. This convergent trend is incorporated in the surface roughness spectrum model to improve the applicable wind speed range for microwave scattering and emission computations.

scholarly journals On direct passive microwave remote sensing of sea spray aerosol production

2014 ◽  
Vol 14 (21) ◽  
pp. 11611-11631 ◽  
Author(s):  
I. B. Savelyev ◽  
M. D. Anguelova ◽  
G. M. Frick ◽  
D. J. Dowgiallo ◽  
P. A. Hwang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Brightness Temperature ◽  
Microwave Remote Sensing ◽  
Ocean Surface ◽  
Breaking Waves ◽  
Passive Microwave ◽  
Microwave Emission ◽  
Sea Spray ◽  
Sea Spray Aerosol ◽  
Microwave Emissions

Abstract. This study addresses and attempts to mitigate persistent uncertainty and scatter among existing approaches for determining the rate of sea spray aerosol production by breaking waves in the open ocean. The new approach proposed here utilizes passive microwave emissions from the ocean surface, which are known to be sensitive to surface roughness and foam. Direct, simultaneous, and collocated measurements of the aerosol production and microwave emissions were collected aboard the FLoating Instrument Platform (FLIP) in deep water ~ 150 km off the coast of California over a period of ~ 4 days. Vertical profiles of coarse-mode aerosol (0.25–23.5 μm) concentrations were measured with a forward-scattering spectrometer and converted to surface flux using dry deposition and vertical gradient methods. Back-trajectory analysis of eastern North Pacific meteorology verified the clean marine origin of the sampled air mass over at least 5 days prior to measurements. Vertical and horizontal polarization surface brightness temperature were measured with a microwave radiometer at 10.7 GHz frequency. Data analysis revealed a strong sensitivity of the brightness temperature polarization difference to the rate of aerosol production. An existing model of microwave emission from the ocean surface was used to determine the empirical relationship and to attribute its underlying physical basis to microwave emissions from surface roughness and foam within active and passive phases of breaking waves. A possibility of and initial steps towards satellite retrievals of the sea spray aerosol production are briefly discussed in concluding remarks.

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