Vol 1, No 1 (Published)





Table of Contents

Editorial

by Jinyu Sheng
118 Views, 67 PDF Downloads
The Satellite Oceanography and Meteorology (SOM) was launched in 2016, in response to the growing use of remotely sensed satellite data in understanding and identifying important processes and phenomena occurring in the atmosphere and ocean. The SOM provides space for oceanographers, meteorologists, hydrologists and climatologists to publish their research papers on theory, science, technology and applications of satellite remote sensing data of the ocean, atmosphere and climate.
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Articles

by Christopher R S Chambers, Gary B Brassington, Jinyu Sheng, Ian Simmonds, Kevin Walsh
162 Views, 58 PDF Downloads
Four east coast lows (ECLs) were simulated with the Weather Research and Forecast model to investigate the influence of the sea surface temperature (SST) distribution on the sea level pressure (SLP). Each ECL was simulated with two different SST datasets: the Bluelink SST field and NCEP skin temperature field. The former resolved eddies in the East Australian Current while the latter did not. The simulated SLP fields in the eddy-resolving SST runs were compared with those in the non-eddy-resolving SST runs. On time-scales of about 48 hours, higher SSTs were asso-ciated with lower SLPs. The spatial scale of the SLP response was similar to that of the ocean eddies, indicative of the rapidity and robustness of the response given the rapidly evolving conditions within the storms. On shorter time-scales, the SLP response to SST change can become substantially larger. The largest reductions in SLP in the eddy-resolving SST runs were associated with regions of deep atmospheric convection that warm the tropospheric column. These areas were shown to be related to the SST distribution with the greatest SLP reductions associated with convection over strong SST gradient regions. The landfall of a damaging convective mesoscale low pressure system on 8 June 2007 was also investigated. It was found that a region of strong SST gradients on the southern flank of a large warm ocean eddy was associated with lower pressures at the time of formation of this meso-low. In addition, the only case that simulated the low pressure at the correct time (albeit at not quite the correct location) was the eddy-resolved SST run. It was hy-pothesized that the development of this meso-low that impacted the coast around Newcastle, was enhanced because of the eddy-scale SST distribution at the time.
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Articles

by Guoqi Han, Nancy Chen, Zhimin Ma
179 Views, 109 PDF Downloads
Annual cycle of sea level off Atlantic Canada has been investigated based on a merged satellite altimetry dataset and a monthly temperature and salinity dataset. The altimetric results were compared with coastal tide-gauge data and steric height calculated from the temperature and salinity dataset. There was a general north-south variation in the amplitude of the altimetric annual cycle, increasing from 4 cm in the Labrador Sea to 15 cm in the Gulf Stream and the North Atlantic Current Region. The annual cycle in the deep ocean can approximately be accounted for by the steric height variability relative to 700 m, in which the thermosteric effect was the dominant contributor. The halosteric effect over the continental slope, especially over the northern Labrador Slope was also important. While the thermosteric effect occurred dominantly at the top 100 m water column, there was substantial halosteric variation in the 100–300 m water column. The annual sea level cycle along the Canadian Atlantic coast showed a complicated pattern in amplitude, but the phase was highly coherent with the highest sea level in fall. The steric height accounts for a substantial portion of the coastal annual cycle, but other factors such as wind forcing may be equally important.
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Articles

by Yongsheng Wu, Jinyu Sheng, Dave Senciall, Charles Tang
121 Views, 117 PDF Downloads
The satellite-based operational sea surface temperature (SST) was compared to the ship-based in-situ SSTs established by the Atlantic Zone Monitoring Program (AZMP) over the eastern Canadian shelf (ECS) for a 3-year anal-ysis period (2005–2007). Two sets of operational SST analyses were considered in this study, with one set produced by the Canadian Meteorological Centre (CMC) and the other produced by the National Centers for Environmental Predic-tion (NCEP). The comparative study indicated that there was no appreciable systematic difference between the CMC and NCEP SST analyses over the ECS. The root mean squared difference (RMSD) between the AZMP ship-based in-situ SSTs and the satellite-based STT analyses over the ECS was about 1.0°C, without any obvious seasonal or geo-graphic trend. The RMSDs were relatively larger over the outer flank of the Grand Banks than the other regions of the ECS, mainly due to dynamically complicated circulation and hydrographic conditions over this shelf break area associated with the Labrador Current.
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Articles

by Shiliang Shan, Jinyu Sheng, Kyoko Ohashi, Mathieu Dever
139 Views, 178 PDF Downloads
This study presents a multi-nested ocean circulation model developed recently for the central Scotian Shelf. The model consists of four submodels downscaling from the eastern Canadian Shelf to the central Scotian Shelf. The model is driven by tides, river discharges, and atmospheric forcing. The model results are validated against observations, including satellite remote sensing data from GHRSST and Aquarius and in situ measurements taken by tide gauges, a marine buoy, ADCPs and CTDs. The ocean circulation model is able to capture variations of sea level, hydrography and the Nova Scotia Current on timescales of days to seasons over the central Scotian Shelf. Model results are used in a process study to examine the effect of tidal mixing and wind-driven coastal upwelling in the formation of cold surface waters along the coast of Nova Scotia.
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Articles

by Yiyong Luo
98 Views, 166 PDF Downloads
A suite of numerical experiments is implemented with an ocean general circulation model (OGCM) to ex-amine the roles of wind stress and wind speed for oceanic changes in the tropical Pacific under global warming. In particular, we turned off the changes of wind stress and/or wind speed in the model to identify the effects of wind-driven ocean circulation and air-sea latent heat flux (i.e., its portion through the wind speed influence on the efficiency of latent heat flux). Results show that 1) the wind stress change appears to be a key forcing mechanism for weakening the tropical surface currents as well as for the oceanic changes in the equatorial thermocline, while it only contributes secondarily to the sea surface temperature (SST) pattern formation in the tropics; 2) the wind speed change is the leading cause for the minimum warming over the southeast subtropics and for a stronger surface warming in the northern hemisphere than in the southern hemisphere; and 3) the enhanced surface warming along the equator is mainly due to the effect of warming in the absence of wind stress and wind speed changes, and this effect also plays a significant role for changing the equatorial thermocline.
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Articles

by Hui Yang, Xinrong Chen, Gui-Ying Yang
137 Views, 165 PDF Downloads
This study examines the relationship between the extensive and persistent extreme cold events (EPECEs) in China and geopotential height anomalies in the stratosphere using daily mean fields of outgoing long wave radiation (OLR) produced by the NCAR and daily atmospheric circulations produced by the NCEP/NCAR. The OLR composite analysis for the EPECE in China demonstrates that the negative OLR height anomalies (cold air) originated from Siberia influence China progressively from north to south. The largest negative OLR height anomaly (cooling event) occurs in the region to the north of the Nanling Mountains. This suggests that the OLR height anomalies can be used to represent the temporal and spatial characteristics of extreme low temperatures and cold air activities in winter in China. The composite analysis of large-scale atmospheric circulations during the EPECE reveals characteristic evolutions of stratospheric and tropospheric circulations during the extreme cold event. We demonstrate the important role of atmospheric circulation anomalies in the outbreak and dissipation of the EPECE in China. We also demonstrate that significant perturbations in the stratospheric circulation occur more than 10 days prior to the outbreak of the EPECE, with positive height anomalies in the Arctic stratosphere. These positive anomalies propagate downward from the stratosphere and affect the formation and development of the high pressure ridge in the middle troposphere over the Ural Mountains. Significant changes also occur in the atmospheric circulation in the mid-latitude stratosphere. These changes propagate downward from the stratosphere and strengthen the low pressure trough in the troposphere in the region to the east of Lake Balkhash and Lake Baikal. Therefore, the changes in the stratospheric circulation during the EPECE in China occur prior to changes in the tropospheric circulation and are very useful for predicting extreme wintertime cold temperatures in China.
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