Vol 2, No 1 (2017)

Table of Contents

Editorial

by Jinyu Sheng
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The journal of Satellite Oceanography and Meteorology (SOM) was launched in 2016 for inspiring and disseminating research papers on theory, science, technology and applications of satellite remote sensing data of the ocean, atmosphere and climate. We welcome research papers in areas of (a) original research results from satellite observations of the regional and global ocean and atmosphere, (b) calibration/validation and research related to future satellite missions, and (c) new satellite-derived products and climate records constructed from satellite observations. We also welcome high-quality research papers in broad research areas including but not limiting to (i) oceanography and marine science; (ii) meteorology and atmospheric science; (iii) air-sea, physical-biological and physical-chemical interactions, and (iv) studies of the Earth’s climate system.

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Articles

by Yuhong Zhang, Junyao Chen, Yan Du
110 Views, 90 PDF Downloads
With the remarkable intensity of 170 knots, Typhoon Haiyan starts as a tropical depression on November 3 and develops to the peak as super tropical cyclone (TC) on November 7 in 2013. This intensity makes Haiyan one of the strongest TCs record ever observed and 35 knots higher than the maximum of the existing highest category. Haiyan originated from the eastern part of the Northwest Pacific Warm Pool and moved westward over warm water with a thick barrier layer (BL). The BL reduced the vertical mixing and entrainment caused by Haiyan and prevented the cold thermocline water into the mixed layer (ML). As a result, sea temperature cooling associated with wind stirring was suppressed. Relative high sea surface temperature (SST) kept fueling Haiyan via latent heat flux release, which favored the rapid development of a “Category 6” super typhoon.
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Articles

by Bartolomeo Doronzo, Stefano Taddei, Carlo Brandini
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In a previous study an improved Maximum Cross-Correlation technique, called Multi-Window Maximum Cross-Correlation (MW-MCC), was proposed, and applied to noise-free synthetic images in order to show its potential and limits in oceanographic applications. In this work, instead, the application of MW-MCC to high resolution MODIS images, and its capability to provide useful and realistic results for ocean currents, is studied. When applied to real satellite images, the MW-MCC is subject to cloud cover and image quality problems. As a consequence the number of useful MODIS images is greatly reduced. However, for every MODIS image, multiple spec-tral bands are available, and it is possible to apply the MW-MCC algorithm to the same scene as many times as the number of these bands, increasing the possibility of finding valid current vectors. Moreover, the comparison among the results from different spectral bands allows to verify both the consistency of the computed current vectors and the validity of using a spectral band as a good tracer for the ocean circulation. Due to the lack of systematic current measurements in the area considered, it has been not possible to perform an ex-tensive error analysis of the MW-MCC results, although a case study of a comparison between HF radar measurements and MW-MCC data is shown. Moreover, some comparison between numerical ocean model simulations and MW-MCC results are also shown. The coherence of the resulting circulation flow, the high number of current vectors found, the agreement among different spectral bands, and conformity with the currents measured by the HF radars or simulated by hydrodynamic models show the validity of the technique.
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Articles

by Douglas E Pirhalla, Scott C Sheridan, Cameron C Lee, Brian B Barnes, Varis Ransibrahmanakul, Chuanmin Hu
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Temporal variability in water clarity for South Florida’s marine ecosystems was examined through satellite-derived light attenuation (Kd) coefficients, in the context of wind- and weather patterns. Reduced water clarity along Florida’s coasts is often the result of abrupt wind-resuspension events and other exogenous factors linked to frontal passage, storms, and precipitation. Kd data between 1998 and 2013 were synthesized to form a normalized Kd index (KDI) and subsequently compared with Self Organizing Map (SOM)-based wind field categorizations to reveal spatiotemporal patterns and their inter-relationships. Kd climatological maximums occur from October through December along southern sections of the West Florida Shelf (WFS) and from January through March along the Florida Straits. Spatial clusters of elevated Kd occur along 3 spatial domains: central WFS, southern WFS, and Florida Straits near the Florida Reef Tract, where intra-seasonal variability is the highest, and clarity patterns are associated with transitional wind patterns sequenced with cyclonic circulation. Temporal wind transitions from southerly to northerly, typically accompanying frontal passages, most often result in elevated Kd response. Results demonstrate the potential of using synoptic climatological analysis and satellite indices for tracking variability in water clarity and other indicators related to biological health.
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Articles

by Qingtao Song, Zhaohui Wang
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Motivated by the shortcomings of radio frequency interferences (RFI) associated with the spaceborne L-band radiometers near the Northwest Pacific and previous study near the Amazon plume, this study presents a sea surface salinity (SSS) retrieval algorithm from the microwave radiometer onboard the HY-2A satellite. The SSS signal is improved by differentiating the reflectance between the C and X band. A reflectance calibration method is proposed by using a combination of radiative transfer model (RTM) and the Klein-Swift emissivity model. Evaluations of the retrieved SSS from the HY-2A satellite indicate that the root mean square error (RMSE) is about 0.35 psu on 0.5 degree grid spacing and monthly time scale which is comparable to the accuracy of SMOS and Aquarius-SAC/D satellites.
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Articles

by Xingrong Chen, Yi Cai, Fangli Qiao
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 The physical decomposition method suggested by Qian (2012) is used to examine the interannual variability of sea surface temperature (SST) and anomaly (SSTA) in the Indian Ocean (IO) for the period 1945.2003. The monthly mean SSTs taken from the global ocean reanalysis produced by the Simple Ocean Data Assimilation (SODA) are decomposed into four terms. The first term is the zonally averaged monthly climatological SST ([Tt(ϕ)]), which features relatively warm surface waters in the tropical IO and relatively colder surface waters over the southern IO. This term also has a relatively low SST pool between the Equator and 20°N. The SST at the center of the pool in summer is about 1-2°C lower than in spring and autumn. The second term is the spatially-varying monthly climatological SSTA (Tt*(λ,ϕ)), due mainly to the topographic effect and seasonal variation in wind forcing. The values of Tt*(λ,ϕ) are negative over the western coastal waters and positive over the eastern coastal and shelf waters in the tropical and northern IO. The third term is the zonally-averaged transient SSTA([T(ϕ,t)']Y). The largest values of [T(ϕ,t)']Y occur over the subtropical and mid-latitudes of the IO, which differs from the SSTA in the tropical waters of the Pacific Ocean. Time series of zonally and meridionally averaged T(ϕ,t)'Y in the tropical-subtropical IO is strongly correlated with the Indian Ocean basin-wide (IOBW) mode. The fourth term is the spatially-varying transient SSTA (T(λ,ϕ,t)*Y']. The REOF analysis of the fourth term demonstrates that the first REOF is correlated strongly with the South Indian Ocean Dipole (SIOD) mode. The second REOF is correlated strongly with the equatorial Indian Ocean dipole (IOD) mode. The third REOF is highly correlated with the tropical IOBW mode.

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Articles

by Hui Yang, Yuanfa Gong, Gui-Ying Yang
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The relationship between tropical convective activities and meridional (north-south) migration of the East Asian jet stream (EAJS) in winter (December-February) is investigated for improving our knowledge of processes affecting the meridional migration of the EAJS. The monthly mean fields of outgoing longwave radiation (OLR) produced by NCAR and monthly atmospheric circulations produced by the NCEP/NCAR are used in this study. For 31 winter seasons between 1980 and 2011, the meridional migration of the winter EAJS is found to be strongly correlated with the present and preceding conditions of tropical convection over Indonesia. The anomalies in the tropical convection over the region in the preceding autumn and even preceding summer are a very useful indicator for the abnormal meridional migration of the wintertime EAJS. When the tropical convection over Indonesia weakens (strengthens), the EAJS has an abnormal southward (northward) migration. The atmospheric circulation associated with the abnormal meridional migration of the EAJS features abnormal air temperatures over the EAJS and its south side. The center of abnormal air temperatures occurs over the region south of the Yangtze River. Abnormal air pressures generated by abnormal air temperatures lead to abnormal winds. In the case of weakened tropical convection (positive OLR anomaly) over Indonesia, ascending motion of air mass over Indonesia is reduced, and the strength of Hadley circulation is weakened over the meridional range of the western Pacific Ocean. Consequently, the high-level air mass to the south of the core of the EAJS abnormally ascends and cools and the nearly southerly divergent winds at high-altitudes weaken, leading to significant reduction of heat transport from tropics to the southern China, with negative anomalies of air temperatures in the EAJS and its south side. The above processes increase thermal winds to the south of the Yangtze River and enhance the high-level westerly winds. To the north of the Yangtze River, both thermal winds and the high-level westerly winds are reduced. As a result, the EAJS has an abnormal south migration. In the case of enhanced tropical convection (negative OLR anomaly) over Indonesia, the opposite happens, in which Hadley circulation strengthens, the air mass to the south of the core of the EAJS abnormally descends and warms, heat transport increases from tropics to the southern China with positive air temperatures anomalies over the EAJS and its south side, and the EAJS has an abnormal northward migration.
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