scholarly journals Comparison of the Infrared Surface Emissivity Model (ISEM) with a Physical Emissivity Model

2010 ◽  
Vol 27 (2) ◽  
pp. 345-352 ◽  
Author(s):  
Sungwook Hong ◽  
Inchul Shin ◽  
Mi-Lim Ou
Keyword(s):  
Refractive Index ◽  
Roughness Parameter ◽  
Satellite Observation ◽  
Sea Surface ◽  
Northwestern Pacific ◽  
Surface Emissivity ◽  
Infrared Wavelength ◽  
Clear Sky ◽  
Infrared Spectral ◽  
Emissivity Model

Abstract Accurate models of surface emissivity are important for interpreting satellite radiance observations. Surface emissivity depends on the satellite zenith angle, roughness, polarization, and refractive index of the surface. The effects of the roughness parameter on emissivity have not been studied thoroughly. By using an infrared geostationary satellite observation and a physical model based on the radiative transfer equation, the forward emissivity model and physical emissivity model are validated in the northwestern Pacific Ocean. First, the unpolarized emissivity at a given view angle and a wavelength of 10.8 μm in the thermal infrared spectral region is decomposed for the clear sky. The refractive index of the sea surface is quantitatively retrieved using the inversion of Fresnel equations. The refractive index of the sea surface derived from the physical emissivity exhibits a reasonable range within the infrared wavelength. The result of this investigation can be applied to the land emissivity model, which has not been studied thoroughly.

Influence of sea surface emissivity model parameters at L-band for the estimation of salinity

2002 ◽  
Vol 23 (23) ◽  
pp. 5117-5122 ◽  
Author(s):  
E. P. Dinnat ◽  
J. Boutin ◽  
G. Caudal ◽  
J. Etcheto ◽  
P. Waldteufel
Keyword(s):  
Sea Surface ◽  
Model Parameters ◽  
Surface Emissivity ◽  
Emissivity Model ◽  
L Band

Efficient downscaling of satellite oceanographic data with convolutional neural networks

2021 ◽  
Vol 12 (3) ◽  
pp. 46-47
Author(s):  
Nikita Saxena
Keyword(s):  
Neural Networks ◽  
Deep Learning ◽  
Convolutional Neural Networks ◽  
Super Resolution ◽  
Sea Surface ◽  
Clear Sky ◽  
Oceanographic Data ◽  
Computationally Expensive ◽  
Sky Conditions ◽  
Data Inference

Space-borne satellite radiometers measure Sea Surface Temperature (SST), which is pivotal to studies of air-sea interactions and ocean features. Under clear sky conditions, high resolution measurements are obtainable. But under cloudy conditions, data analysis is constrained to the available low resolution measurements. We assess the efficiency of Deep Learning (DL) architectures, particularly Convolutional Neural Networks (CNN) to downscale oceanographic data from low spatial resolution (SR) to high SR. With a focus on SST Fields of Bay of Bengal, this study proves that Very Deep Super Resolution CNN can successfully reconstruct SST observations from 15 km SR to 5km SR, and 5km SR to 1km SR. This outcome calls attention to the significance of DL models explicitly trained for the reconstruction of high SR SST fields by using low SR data. Inference on DL models can act as a substitute to the existing computationally expensive downscaling technique: Dynamical Downsampling. The complete code is available on this Github Repository.

scholarly journals Influence of Oceanic Parameters on Aquarius L-Band Sea Surface Emissivity

2021 ◽  
Vol 1961 (1) ◽  
pp. 012065
Author(s):  
Yanyan Li ◽  
Zhenzhan Wang ◽  
Yiqiang Hu ◽  
Xiaolin Tong
Keyword(s):  
Sea Surface ◽  
Surface Emissivity ◽  
L Band

scholarly journals Impacts of the Kuroshio Intrusion through the Luzon Strait on the Local Precipitation Anomaly

2021 ◽  
Vol 13 (6) ◽  
pp. 1113
Author(s):  
Wen-Pin Fang ◽  
Ding-Rong Wu ◽  
Zhe-Wen Zheng ◽  
Ganesh Gopalakrishnan ◽  
Chung-Ru Ho ◽  
...  
Keyword(s):  
Kuroshio Current ◽  
Precipitation Anomaly ◽  
Luzon Strait ◽  
Sea Surface ◽  
Research Quality ◽  
Northwestern Pacific ◽  
Kuroshio Intrusion ◽  
Vertical Advection ◽  
Budget Analysis ◽  
The Kuroshio

The Kuroshio Current has its origin in the northwestern Pacific, flowing northward to the east of Taiwan and the northern part of Luzon Island. As the Kuroshio Current flows northward, it quasi-periodically intrudes (hereafter referred to as Kuroshio intrusion (KI)) into the northern South China Sea (SCS) basin through the Luzon Strait. Despite the complex generation mechanisms of KI, the purpose of this study is to improve our understanding of the effects of KI through the Luzon Strait on the regional atmospheric and weather variations. Long-term multiple satellite observations, including absolute dynamic topography, absolute geostrophic currents, sea surface winds by ASCAT, multi-scale ultra-high resolution sea surface temperature (MURSST) level-four analysis, and research-quality three-hourly TRMM multi-satellite precipitation analysis (TMPA), was used to systematically examine the aforementioned scientific problem. Analysis indicates that the KI is interlinked with the consequential anomalous precipitation off southwestern Taiwan. This anomalous precipitation would lead to ~560 million tons of freshwater influx during each KI event. Subsequently, independent moisture budget analysis suggests that moisture, mainly from vertical advection, is the possible source of the precipitation anomaly. Additionally, a bulk formula analysis was applied to understand how KI can trigger the precipitation anomaly through vertical advection of moisture without causing an evident change in the low-level flows. These new research findings might reconcile the divisiveness on why winds are not showing a synchronous response during the KI and consequential anomalous precipitation events.

Variational assimilation of observation data in the mathematical model of the Baltic Sea dynamics

2015 ◽  
Vol 30 (4) ◽  
Author(s):  
Valeriy I. Agoshkov ◽  
Eugene I. Parmuzin ◽  
Vladimir B. Zalesny ◽  
Victor P. Shutyaev ◽  
Natalia B. Zakharova ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Baltic Sea ◽  
Satellite Observation ◽  
Sea Surface ◽  
Observation Data ◽  
The Baltic Sea ◽  
Variational Assimilation ◽  
The Baltic ◽  
The Mathematical Model

AbstractA mathematical model of the dynamics of the Baltic Sea is considered. A problem of variational assimilation of sea surface temperature (SST) data is formulated and studied. Based on variational assimilation of satellite observation data, an algorithm solving the inverse problem of heat flux restoration on the interface of two media is proposed. The results of numerical experiments reconstructing the heat flux functions in the problem of variational assimilation of SST observation data are presented. The influence of SST assimilation on other hydrodynamic parameters of the model is considered.

scholarly journals Mode Sensitivity Exploration of Silica–Titania Waveguide for Refractive Index Sensing Applications

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7452
Author(s):  
Muhammad A. Butt ◽  
Andrzej Kaźmierczak ◽  
Cuma Tyszkiewicz ◽  
Paweł Karasiński ◽  
Ryszard Piramidowicz
Keyword(s):  
Refractive Index ◽  
High Performance ◽  
Near Infrared ◽  
Sol Gel ◽  
Cost Effective ◽  
Dip Coating ◽  
Infrared Wavelength ◽  
Refractive Index Sensing ◽  
Sensing Applications ◽  
Coating Method

In this paper, a novel and cost-effective photonic platform based on silica–titania material is discussed. The silica–titania thin films were grown utilizing the sol–gel dip-coating method and characterized with the help of the prism-insertion technique. Afterwards, the mode sensitivity analysis of the silica–titania ridge waveguide is investigated via the finite element method. Silica–titania waveguide systems are highly attractive due to their ease of development, low fabrication cost, low propagation losses and operation in both visible and near-infrared wavelength ranges. Finally, a ring resonator (RR) sensor device was modelled for refractive index sensing applications, offering a sensitivity of 230 nm/RIU, a figure of merit (FOM) of 418.2 RIU−1, and Q-factor of 2247.5 at the improved geometric parameters. We believe that the abovementioned integrated photonics platform is highly suitable for high-performance and economically reasonable optical sensing devices.

scholarly journals Seasonal Sea Surface Temperature Asymmetry in the Northwestern Pacific Marginal Seas

2015 ◽  
Vol 26 (3) ◽  
pp. 331 ◽  
Author(s):  
Hyeonyeong Kwak ◽  
Yang-Ki Cho ◽  
Gwang-Ho Seo ◽  
Yong-Jin Tak ◽  
Hyo-Seok Park ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Northwestern Pacific ◽  
Marginal Seas ◽  
Temperature Asymmetry
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