scholarly journals Aircraft measurements on vertical changes in aerosol parameters - Remote sensing with detection of upwelling radiance from an atmosphere-ocean surface system.

1989 ◽  
Vol 41 (10) ◽  
pp. 851-870 ◽  
Author(s):  
Y. IWASAKA ◽  
C. X. ZHANG ◽  
K. YOSHIMI
2019 ◽  
Vol 11 (7) ◽  
pp. 746 ◽  
Author(s):  
Feng Xu ◽  
David Diner ◽  
Oleg Dubovik ◽  
Yoav Schechner

Aerosol retrieval algorithms used in conjunction with remote sensing are subject to ill-posedness. To mitigate non-uniqueness, extra constraints (in addition to observations) are valuable for stabilizing the inversion process. This paper focuses on the imposition of an empirical correlation constraint on the retrieved aerosol parameters. This constraint reflects the empirical dependency between different aerosol parameters, thereby reducing the number of degrees of freedom and enabling accelerated computation of the radiation fields associated with neighboring pixels. A cross-pixel constraint that capitalizes on the smooth spatial variations of aerosol properties was built into the original multi-pixel inversion approach. Here, the spatial smoothness condition is imposed on principal components (PCs) of the aerosol model, and on the corresponding PC weights, where the PCs are used to characterize departures from the mean. Mutual orthogonality and unit length of the PC vectors, as well as zero sum of the PC weights also impose stabilizing constraints on the retrieval. Capitalizing on the dependencies among aerosol parameters and the mutual orthogonality of PCs, a perturbation-based radiative transfer computation scheme is developed. It uses a few dominant PCs to capture the difference in the radiation fields across an imaged area. The approach is tested using 27 observations acquired by the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) during multiple NASA field campaigns and validated using collocated AERONET observations. In particular, aerosol optical depth, single scattering albedo, aerosol size, and refractive index are compared with AERONET aerosol reference data. Retrieval uncertainty is formulated by accounting for both instrumental errors and the effects of multiple types of constraints.


2013 ◽  
Vol 30 (9) ◽  
pp. 2168-2188 ◽  
Author(s):  
Paul A. Hwang ◽  
Derek M. Burrage ◽  
David W. Wang ◽  
Joel C. Wesson

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.


2005 ◽  
Author(s):  
Jingsong Yang ◽  
Weigen Huang ◽  
Qingmei Xiao ◽  
Changbao Zhou ◽  
Paris W. Vachon

1999 ◽  
Vol 56 (14) ◽  
pp. 2345-2358 ◽  
Author(s):  
Kenneth Sassen ◽  
Gerald G. Mace ◽  
Zhien Wang ◽  
Michael R. Poellot ◽  
Stephen M. Sekelsky ◽  
...  

2016 ◽  
Vol 40 (2) ◽  
pp. 215-246 ◽  
Author(s):  
Jamie D. Shutler ◽  
Graham D. Quartly ◽  
Craig J. Donlon ◽  
Shubha Sathyendranath ◽  
Trevor Platt ◽  
...  

Physical oceanography is the study of physical conditions, processes and variables within the ocean, including temperature–salinity distributions, mixing of the water column, waves, tides, currents and air–sea interaction processes. Here we provide a critical review of how satellite sensors are being used to study physical oceanography processes at the ocean surface and its borders with the atmosphere and sea ice. The paper begins by describing the main sensor types that are used to observe the oceans (visible, thermal infrared and microwave) and the specific observations that each of these sensor types can provide. We then present a critical review of how these sensors and observations are being used to study: (i) ocean surface currents, (ii) storm surges, (iii) sea ice, (iv) atmosphere–ocean gas exchange and (v) surface heat fluxes via phytoplankton. Exciting advances include the use of multiple sensors in synergy to observe temporally varying Arctic sea ice volume, atmosphere–ocean gas fluxes, and the potential for four-dimensional water circulation observations. For each of these applications we explain their relevance to society, review recent advances and capability, and provide a forward look at future prospects and opportunities. We then more generally discuss future opportunities for oceanography-focused remote sensing, which includes the unique European Union Copernicus programme, the potential of the International Space Station and commercial miniature satellites. The increasing availability of global satellite remote-sensing observations means that we are now entering an exciting period for oceanography. The easy access to these high quality data and the continued development of novel platforms is likely to drive further advances in remote sensing of the ocean and atmospheric systems.


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