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Ocean color and sea surface temperature data from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra satellite are used to study the cross-shelf circulation and transport of suspended sediments in the Yellow and the East China Seas. The ocean color images show a significant turbid water plume extending in the southeast direction from the Subei coasts of China to the shelf edge south of Cheju during fall–winter, suggesting significant cross-shelf currents in the Yellow Sea/East China Sea in winter. The currents transport suspended sediments from the area of the old Huanghe mouth into the Okinawa Trough. Part of the turbid plume joins the Yellow Sea Warm Current to enter the Yellow Sea trough in winter. The satellite images suggest that the time scales of cross-shelf transport and surface-to-subsurface descending of the suspended sediments are a few weeks. The turbid plume grows in fall, reaches its maximum expansion and intensity in winter–spring, and subsides in late spring. In summer, the plume becomes coastally trapped. Substantial interannual variations of the intensity and coverage of the turbid plume are indicated by the observations. In comparison, the Changjiang Diluted Water in summer only transports a small amount of the Changjiang suspended sediment to the outer shelf south of Cheju, which does not enter the Yellow Sea owing to the weak intrusion of the Yellow Sea Warm Current in summer. The dynamics of the cross-shelf circulation in the Yellow Sea in winter are hypothesized to be associated with (1) the convergence of the Yellow Sea Coastal Current and the Taiwan Warm Current off the Changjiang mouth and (2) the time-dependent forcing of the northerly wind bursts that drives the intrusion of the Yellow Sea Warm Current.

The cold-water event along the southeast coast of the United States in the summer of 2003 is studied using satellite data combined with in situ observations. The analysis suggests that the cooling is produced by wind-driven coastal upwelling, which breaks the thermocline barrier in the summer of 2003. The strong and persistent southwesterly winds in the summer of 2003 play an important role of lifting the bottom isotherms up to the surface and away from the coast, generating persistent surface cooling in July–August 2003. Once the thermocline barrier is broken, the stratification in the nearshore region is weakened substantially, allowing further coastal cooling of large magnitudes by episodic southerly wind bursts or passage of coastally trapped waves at periods of a few days. These short-period winds or waves would otherwise have no effects on the surface temperature because of the strong thermocline barrier in summer if not for the low-frequency cooling produced by the persistent southwesterly winds.

An ocean general circulation model (OGCM) is used to study the roles of equatorial waves and western boundary reflection in the seasonal circulation of the equatorial Indian Ocean. The western boundary reflection is defined as the total Kelvin waves leaving the western boundary, which include the reflection of the equatorial Rossby waves as well as the effects of alongshore winds, off-equatorial Rossby waves, and nonlinear processes near the western boundary. The evaluation of the reflection is based on a wave decomposition of the OGCM results and experiments with linear models. It is found that the alongshore winds along the east coast of Africa and the Rossby waves in the off-equatorial areas contribute significantly to the annual harmonics of the equatorial Kelvin waves at the western boundary. The semiannual harmonics of the Kelvin waves, on the other hand, originate primarily from a linear reflection of the equatorial Rossby waves. The dynamics of a dominant annual oscillation of sea level coexisting with the dominant semiannual oscillations of surface zonal currents in the central equatorial Indian Ocean are investigated. These sea level and zonal current patterns are found to be closely related to the linear reflections of the semiannual harmonics at the meridional boundaries. Because of the reflections, the second baroclinic mode resonates with the semiannual wind forcing; that is, the semiannual zonal currents carried by the reflected waves enhance the wind-forced currents at the central basin. Because of the different behavior of the zonal current and sea level during the reflections, the semiannual sea levels of the directly forced and reflected waves cancel each other significantly at the central basin. In the meantime, the annual harmonic of the sea level remains large, producing a dominant annual oscillation of sea level in the central equatorial Indian Ocean. The linear reflection causes the semiannual harmonics of the incoming and reflected sea levels to enhance each other at the meridional boundaries. In addition, the weak annual harmonics of sea level in the western basin, resulting from a combined effect of the western boundary reflection and the equatorial zonal wind forcing, facilitate the dominance by the semiannual harmonics near the western boundary despite the strong local wind forcing at the annual period. The Rossby waves are found to have a much larger contribution to the observed equatorial semiannual oscillations of surface zonal currents than the Kelvin waves. The westward progressive reversal of seasonal surface zonal currents along the equator in the observations is primarily due to the Rossby wave propagation.

A jet flowing in the Kelvin wave propagation direction along the seaward side of a continental slope is found to decrease in strength as it leaks mass onto the continental shelf. As a result, a shelf break jet flowing in the opposite direction is induced on the shelf. The combination of these two flows creates a decaying, high-pressure tongue centered about the shelf break. An idealized, reduced gravity model is developed to examine the two-flow combination. In the model a baroclinic open ocean jet flows next to a continental shelf over which the flow is barotropic and dominated by a linear bottom friction proportional to along-shelf velocity. The far-field depth of the thermocline is assumed to be much greater than the depth of the shelf break. A solution is found in the limit of small cross-slope flow. The mathematical problem of finding the flow on the shelf is equivalent to that of heat conduction on a semi-infinite rod with a finite heat source placed at the end of the rod. A numerical shelf/slope junction model is devised to allow the requirement of small cross-slope flow to be relaxed. The numerical model, which incorporates higher-order dynamics, confirms the qualitative results obtained from the analytic model. The motivation for the development of the theory lies in observational evidence of a northward flowing jet along the continental slope off the West Florida Shelf, apparently stemming from the Loop Current. The structure of the flow combination over the shelf break is confirmed with historical hydrographic data and advanced very high resolution radiometer imagery.

An assimilation of routine sea surface temperature observations is conducted to estimate the sea surface heat flux in the Yellow Sea during the winter of 1986. Ten-day mean SST compilations, published by the Japan Meteorological Agency, are used. The time window is from 0000 Japan Local Time (JLT) 21 January to 0000 JLT 21 February 1986. Because there are only three frames of the observed temperature available for the time window, only a steady-state distribution of the heat flux is determined. A tonguelike feature of the optimized heat flux distribution is consistent with the warm SST anomaly at the center of the Yellow Sea trough. The optimized heat flux generates improved simulation of the cooling trend of the temperature time series. The variational method is the assimilation procedure employed. The developed scheme is able to optimize simultaneously the initial temperature condition and the sea surface heat flux without a priori knowledge of either. A coarse-resolution Hessian is used to eva...

Many state-of-the-art numerical ocean models calculate pressure using the hydrostatic balance, or an equation derived from it. The proper form of this deceptively simple-looking equation, ∂p/∂z = −gρ(S, T, p) (where notation is standard), is nonlinear in the pressure p. In contrast, most numerical models solve the linear equation ∂p/∂z = −gρ(S, T, z). This modification essentially replaces the total pressure, which includes a time-dependent signal, with an approximate time-independent pressure associated with the depth of a model grid point. In this paper, the authors argue that the inclusion of the total pressure when solving the hydrostatic equation can generate a depth-dependent baroclinic pressure gradient equivalent to a geostrophic velocity of several centimeters per second. Further, this effective velocity can increase with depth and is largest in dynamically important areas like western boundary currents. These points suggest that the full feedback of pressure on density should be include...

A vertically integrated model that incorporates horizontal temperature variations is used to study the circulation of the Yellow Sea in a wintertime period for which velocity and temperature measurements are available at several moorings locations along a central trough. The model features realistic bottom topography and is forced with wind stress and heat flux fields from 13 January to 22 February 1986. The model also incorporates, as a boundary condition, sea-level fluctuations derived from coastal and insular tide gauge stations along model boundaries in open waters. The model reproduces well sea level fluctuations along the coasts of both China and Korea. The hindcast velocity time series, particularly for the north–south component, track those obtained from direct measurements at the moorings. The model momentum balance indicates that the northward flow in the trough is driven by a sea level setup to the south in response to northerly wind bursts in the winter monsoon. The sea-level fluctuat...

With improving of the complexity level of the large software system, the number of code line shows geometrical multiples growth, so software reliability become more and more difficult to be guaranteed. The traditional test security measure must spend a lot of manpower and time to complete. And the system itself needs more reliability to run. In some key fields, such as aviation, spaceflight, its reliability requirements is especially important. The reliability of the software in the system is directly related to their own reputation and survival development competition ability. This paper presents a method to evaluate the software reliability using Fuzzy-Neural network. In order to improve the accuracy of the evaluation, this paper established a reliability prediction model based on adaptive-network based fuzzy inference system (ANFIS). The model use the reliability data(defect counts of every thousand code lines) of one software project as input data, and use the prediction of reliability as output data, training Adaptive-Fuzzy neural network, get the membership function of defect counts of every thousand code lines.

Theory and practice have proven that the cost of building materials accounts for a significant proportion in construction. The material saving is very cost-effective method for the enterprise, strengthen the material procurement management, timely, adequate, appropriate quality, suitable price to complete the procurement task is the goal of each enterprise; At present, resting on the building materials management by Project, this article focuses on the actual construction material purchasing pattern of current construction market and the analysis of the modern purchasing skill's merit and demerit. To promote the development of modern project management and improve the enterprise economic benefit, the "One Body Two Wings" materials procurement management system model and the system function analysis are presented in this paper, whichstarting from procurement process management of the construction materials, based on the system engineering theory, project management criteria and IT technical aids.

[1] The evolution of freshwater plumes and the associated salinity fronts in the northern Bay of Bengal ( henceforth the bay) is studied using rotated empirical orthogonal function (REOF) analysis and extended associate pattern analysis (EAPA). The results show that sea surface salinity distribution is featured by eastern-bay and western-bay plumes in the northern bay during different seasons. The western-bay plume begins in early July, peaks in late August, and then turns into a bay-shaped plume with the two plumes in either side of the bay, which peaks in late October. The southward extension of the western-bay plume can be explained by the southwestward geostrophic flow associated with the cyclonic gyre in the northern bay, which counters the northeastward Ekman drift driven by wind stress. The offshore expansion of the western-bay plume is induced by the offshore Ekman drift which also produces a salinity front near the east coast of India. The bay-shaped plume appears when the cyclonic gyre shifts westward and a weak anticyclonic gyre occupies the northeastern bay. As the season advances, the western part of the bay-shaped plume decays while the eastern part persists until the following June, which is believed to be associated with the anticyclonic gyre in the northern bay. The evolution of the plumes except the eastern part of the bay-shaped plume in fall can be partly explained by the seasonal variation of mass transport associated with the Sverdrup balance. The fact that the western-bay (eastern-bay) plume appears when surface freshwater flux in the northeastern bay increases ( decreases) dramatically suggests that the plumes are not produced directly by surface freshwater flux. River discharge seems to be the freshwater source for the plumes and has little to do with the evolution of the plumes.

Anti-cyclonic eddies northwest of Luzon of the Philippines in summer-fall are identified in the merged data products of satellite altimeters of Topex/Poseidon, Jason-1 and European Research Satellites. The generation and propagation of the anti-cyclonic eddies, which are confirmed by satellite ocean color data, are found to be a seasonal phenomenon that is phase-locked to the onset of the southwesterly monsoon and the relaxation of the cyclonic wind curl in the northeastern South China Sea. The eddies originate from northwest of Luzon in summer, move across the northeastern South China Sea to reach the China continental slope in fall, and propagate southwestward along the continental slope in fall-winter, inducing shelfbreak current variations in the western South China Sea in fall-winter. The anti-cyclonic eddy discovered by Li et al. (1998) in the northern South China Sea is found to originate from northwest of Luzon and carry primarily the South China Sea waters. It does not appear to be an eddy shed from the Kuroshio in the Luzon Strait area as alluded by Li et al. (1998) and others.

[ 1] Intraseasonal variability of Indian Ocean sea surface temperature (SST) during boreal winter is investigated by analyzing available data and a suite of solutions to an ocean general circulation model for 1998 - 2004. This period covers the QuikSCAT and Tropical Rainfall Measuring Mission (TRMM) observations. Impacts of the 30 - 90 day and 10 - 30 day atmospheric intraseasonal oscillations (ISOs) are examined separately, with the former dominated by the Madden-Julian Oscillation (MJO) and the latter dominated by convectively coupled Rossby and Kelvin waves. The maximum variation of intraseasonal SST occurs at 10 degrees S - 2 degrees S in the wintertime Intertropical Convergence Zone (ITCZ), where the mixed layer is thin and intraseasonal wind speed reaches its maximum. The observed maximum warming ( cooling) averaged over ( 60 degrees E - 85 degrees E, 10 degrees S - 3 degrees S) is 1.13 degrees C ( - 0.97 degrees C) for the period of interest, with a standard deviation of 0.39 degrees C in winter. This SST change is forced predominantly by the MJO. While the MJO causes a basin-wide cooling ( warming) in the ITCZ region, submonthly ISOs cause a more complex SST structure that propagates southwestward in the western-central basin and southeastward in the eastern ocean. On both the MJO and submonthly timescales, winds are the deterministic factor for the SST variability. Short-wave radiation generally plays a secondary role, and effects of precipitation are negligible. The dominant role of winds results roughly equally from wind speed and stress forcing. Wind speed affects SST by altering turbulent heat fluxes and entrainment cooling. Wind stress affects SST via several local and remote oceanic processes.

[ 1] Satellite ocean color, sea surface temperature, and altimeter data are used to study the surface Kuroshio path in the Luzon Strait area. The results suggest that the dominant path of surface Kuroshio intrusion in winter is a direct route from northeast of Luzon to southwest of Taiwan and then westward along the continental slope of northern South China Sea. Anticyclonic intrusions of the Kuroshio in the Luzon Strait area are observed during less than 30% of the time on average and in all four seasons of the year. Winter is the most favorable season for the formation of the anticyclonic intrusions. However, the Kuroshio is observed to deviate from the dominant path during only a little over one third of the wintertime on average. The loop currents of the Kuroshio, which feature prominent inflow-outflow currents in the Luzon Strait during the anticyclonic intrusions, are observed only occasionally, with more episodes in summer than in winter. The observation of more frequent loop currents of the Kuroshio in summer than in winter is a revision to the existing conclusion. These results demonstrate that the anticyclonic intrusion of the Kuroshio is a transient phenomenon rather than a persistent circulation pattern in the Luzon Strait area as suggested by some of the existing numerical model simulations. The growth and decay of the anticyclonic intrusions of the Kuroshio are closely related to the passages and evolution of mesoscale eddies in the Luzon Strait area. Each anticyclonic intrusion event lasts for a few weeks. Its termination sometimes results in a detached anticyclonic eddy propagating to the western basin along the continental slope of the northern South China Sea.

[1] Images of chlorophyll-a concentration of the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard of Terra Satellite show significant cross-shelf penetrating fronts off the southeast coast of China in October 2000 and July 2002. Analyses indicate that the significant offshore excursion of the October 2000 front is produced by a cross-shelf jet that coincides with passages of atmospheric cold fronts, which generate downwelling favorable winds. The frontal activities during July 2002 are associated with strong southwesterly winds in favor of upwelling and are likely produced by instabilities of the coastal currents. Multiple fronts within the tongue of the Changjiang (Yangtze River) Diluted Water are observed in the summer of 2002. The significant cross-shelf jet, the instability waves, and the multiple tongues of the Changjiang Diluted Water are reported for the first time.

[1] The dynamics of the seasonal cycle of the equatorial Pacific Ocean circulation are investigated in a hindcast study generated by the Poseidon quasi-isopycnal general ocean circulation model forced by wind stress from a Special Sensor Microwave Imager product and heat flux from an atmospheric mixed layer model. The simulated annual and semi-annual oscillations are validated by the Tropical Atmosphere-Ocean mooring measurements and the altimetry sea levels on the equator, based on which the roles of the equatorial Kelvin and Rossby waves in the seasonal cycle dynamics are investigated. The Kelvin and Rossby waves are extracted from the hindcast in such a way as to treat the model zonal nonlinear momentum terms and wind stress as forcing terms so that the validity of the linear theory on wave propagation and reflection can be examined. It is found that the reflections of the first baroclinic mode waves at the Pacific western and eastern boundaries are in good agreement with the linear theory. In comparison, the reflections of the second and higher baroclinic mode waves are significantly different from the linear theory, suggesting that the reflections are potentially nonlinear. The hindcast has simulated the westward propagation of the dominant annual oscillations of the seasonal sea level in the central basin and the eastward propagation of the dominant semi-annual oscillations of the seasonal sea level in the western and eastern basins successfully. The westward propagation of the annual oscillations is primarily associated with the annual Rossby waves forced by the annual winds in the eastern-to-central equatorial Pacific, the upwelling phase of which forces progressive springtime reversal of the surface zonal currents from the east to the west. However, the internal dynamics of the ocean alter the amplitudes and phases of the springtime reversal significantly. The results of this study have shown that the internal dynamics of the ocean are an important source of the semi-annual oscillations in the equatorial Pacific Ocean. The semi-annual harmonics of the Rossby waves are boosted by the internal dynamics and eventually dominate the seasonal cycle in the far western Pacific. The reflections of the Rossby waves at the western boundary produce semi-annual dominant Kelvin waves, which force significant semi-annual oscillations of sea level in the eastern basin.

This study compares horizontal gradients of sea surface temperature (SST) observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard of Terra satellite with those in the Reynolds analysis. Large differences exists in the horizontal gradients between the two SST products, suggesting that existing surface heat balance analyses based on the Reynolds SST analysis is inaccurate. Impact of the inaccuracies on the surface heat balance of the equatorial Pacific region during 2001-02 is estimated. Sensitivity of the SST horizontal gradients with respect to the grid resolution of the data is also studied and the importance of horizontal diffusion in surface heat balance of the coarse-resolution grid is suggested.

The Moderate-resolution Imaging Spectroradiometer (MODIS) mission is entering it's fourth year of successful operation and has yielded staggering amounts of data types and volumes. After the first MODIS launch in November 1999 on board the Tera satellite, a second instrument was bought to orbit on board of the Aqua satellite in May 2002. Both instruments can provide global coverage in 250-1000 m resolutions in just one day. The distribution of all MODIS data by any single NASA Distributed Active Archive Center (DAAC) is not feasible. Thus, the Goddard Earth Sciences (GES) DAAC produces Level 1A and 1B, and distributes the latter as well as the higher level of Ocean and Atmosphere products. Our goal is to give a generic picture of MODIS products and services available from GES DAAC, intended for users introducing themselves to the MODIS mission.

[1] A numerical hindcast of the Pacific Ocean circulation for the period of 1988–1998 is conducted to study the dynamics of interannual variations in the 1990s. The Poseidon quasi-isopycnal ocean model is forced with an SSMI-derived wind stress product and sea surface heat flux from an atmospheric mixed layer model. On the basis of a good comparison of the hindcast results with TAO mooring observations, the roles of the propagation and reflection of the equatorial Kelvin and Rossby waves in the evolution of El Nino and La Nina events in the 1990s are investigated. The linear waves are extracted from the nonlinear model in such a way as to preserve model nonlinearity so that the validity of linear theory of the wave propagation and reflection at the western and eastern boundaries can be examined. It is found that the reflection of the Kelvin waves at the eastern boundary is in very good agreement with a linear reflection at a straight meridional wall. In contrast, the reflection of the Rossby waves at the Pacific western boundary is significantly different from linear theory. Besides the validation of linear theory, the decomposition also shows marked differences from altimetry data analyses. Since the hindcast solution is dynamically consistent and close to observations, a significant part of the differences is attributed to errors associated with the incomplete (least squares fit) wave decomposition from the altimetry data. On the basis of the wave decomposition, the dynamics of the simulated El Nino and La Nina events in the 1990s are compared with three ENSO paradigms. The investigation shows that precursive Rossby waves, important in the Delayed Oscillator paradigm, played an important role in the termination of the 1991–1993 and the 1997–1998 El Nino events. Reflected Rossby waves from the Pacific eastern boundary, the primary negative feedback in the Advective-Reflective paradigm, were present during the termination of the 1994–1995 and the 1997–1998 El Nino. The Western Pacific Oscillator is at best at work during the decay of the 1997–1998 El Nino; however, it played a minor role compared with the other paradigms. None of the three paradigms appears to describe the termination of the 1988–1989 and the 1995–1996 La Nina events and the onset of the 1997–1998 El Nino event well.

[1] An assimilation of satellite-derived sea surface temperature (SST) observations into the Poseidon quasi-isopycnal ocean model is conducted to study the seasonal cycle of surface thermodynamics of the equatorial Pacific Ocean and to estimate the sea surface heat flux inversely from the SST observations. A simplified approach in the use of the thermodynamic submodel that separates the momentum and the temperature fields in the variational assimilation procedure proves successful in improving the model simulation of the observed SST. From a comparison with several existing bulk estimates, it is seen that the seasonal cycle of sea surface heat flux has been captured well by the inversion except in the eastern equatorial Pacific, where the optimized surface heat flux shows an upward flux during the boreal summer/fall season when the cold tongue SST starts to decrease dramatically. This spurious upward surface heat flux is inconsistent with the bulk estimates and is determined to be due to model deficiencies in calculating vertical turbulent diffusion. The SST data assimilation is shown to have improved the model simulation of horizontal temperature advection significantly. A comparison of the inferred heat budget is made with an analysis by Wang and McPhaden [1999] from TAO mooring observations.