If model parameterizations of unresolved physics, such as the variety of upper ocean mixing processes, are to hold over the large range of time and space scales of importance to climate, they must be strongly physically based. Observations, theories, and models of oceanic vertical mixing are surveyed. Two distinct regimes are identified: ocean mixing in the boundary layer near the surface under a variety of surface forcing conditions (stabilizing, destabilizing, and wind driven), and mixing in the ocean interior due to internal waves, shear instability, and double diffusion (arising from the different molecular diffusion rates of heat and salt). Mixing schemes commonly applied to the upper ocean are shown not to contain some potentially important boundary layer physics. Therefore a new parameterization of oceanic boundary layer mixing is developed to accommodate some of this physics. It includes a scheme for determining the boundary layer depth h, where the turbulent contribution to the vertical shear of a bulk Richardson number is parameterized. Expressions for diffusivity and nonlocal transport throughout the boundary layer are given. The diffusivity is formulated to agree with similarity theory of turbulence in the surface layer and is subject to the conditions that both it and its vertical gradient match the interior values at h. This nonlocal “K profile parameterization” (KPP) is then verified and compared to alternatives, including its atmospheric counterparts. Its most important feature is shown to be the capability of the boundary layer to penetrate well into a stable thermocline in both convective and wind-driven situations. The diffusivities of the aforementioned three interior mixing processes are modeled as constants, functions of a gradient Richardson number (a measure of the relative importance of stratification to destabilizing shear), and functions of the double-diffusion density ratio, Rρ. Oceanic simulations of convective penetration, wind deepening, and diurnal cycling are used to determine appropriate values for various model parameters as weak functions of vertical resolution. Annual cycle simulations at ocean weather station Papa for 1961 and 1969–1974 are used to test the complete suite of parameterizations. Model and observed temperatures at all depths are shown to agree very well into September, after which systematic advective cooling in the ocean produces expected differences. It is argued that this cooling and a steady salt advection into the model are needed to balance the net annual surface heating and freshwater input. With these advections, good multiyear simulations of temperature and salinity can be achieved. These results and KPP simulations of the diurnal cycle at the Long-Term Upper Ocean Study (LOTUS) site are compared with the results of other models. It is demonstrated that the KPP model exchanges properties between the mixed layer and thermocline in a manner consistent with observations, and at least as well or better than alternatives.

Oceanic vertical mixing: a review and a model with a nonlocal boundary layer parameterization

Detecting large scale conversion of mangroves to aquaculture with change point and mixed-pixel analyses of high-fidelity MODIS data

Several methods of extraction and analytical determination for total petroleum hydrocarbons (TPHCs) in aqueous and solid samples are reviewed. Infrared spectroscopy is one of the efficient methods that are being replaced today pursuant to getting rid of some halogenated solvents classified as ozone-depleting substances. The gravimetric method which uses n-hexane as an extraction solvent for the determination of oil and grease, as well as the nonpolar materials, has become a preferred choice, despite being not suitable for volatiles because of the mandatory evaporation step. Other frequently used methods include gas chromatography with a flame ionization detector (FID) or mass spectrometric detector (MSD) which has the capacity to reveal the type of hydrocarbons present and is applicable to both volatile and semivolatile samples. Ultraviolet fluorescence is another method that is available both as a portable field device and as off-site laboratory equipment. Each of the methods has its own advantages and disadvantages; hence, the choice of method is guided by the type of data needed as discussed in detail in this review. The distribution of TPHC in water and sediments across the globe and the factors influencing the distribution were also reviewed.

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Analytical Methods for the Determination of the Distribution of Total Petroleum Hydrocarbons in the Water and Sediment of Aquatic Systems: A Review

Coastal marine sediment samples were collected from ten sampling stations along the Egyptian Mediterranean coast in April 2010. All sediment samples were analyzed for aliphatic (C7 to C34) and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total aliphatic hydrocarbons ranged from 1621.82 to 9069.99 ng/g (dry weight), while aromatic hydrocarbons (16 PAHs) varied between 208.69 and 1020.02 ng/g with an average of 530.68 ± 225.86 ng/g dwt. Good correlations observed between certain PAH concentrations allowed to identify its origin. The average TOC percent was varied from 0.13 to 1.46 %. Principal component analysis was used to determine the sources of hydrocarbon pollutants in sediments of Mediterranean. Additionally, special PAHs compound ratios suggest the petrogenic origins.

Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments of the Mediterranean: assessment and source recognition of petroleum hydrocarbons

Petroleum hydrocarbon status of the Buffalo River Estuary in East London, South Africa, was evaluated from January to May, 2016 Surface water and sediment samples were collected from five points in the estuary and extracted using standard methods The extracts were subsequently analyzed by gas chromatography-flame ionization detection Results showed that total petroleum hydrocarbon (TPH) varied from 765 to 477 μg/L in the water and 1259 to 1,100 mg/kg in the sediments, with mean values of 14650 ± 2796 μg/L and 20981 ± 6382 mg/kg, respectively Concentrations of TPH in the sediments correlated significantly with organic carbon (OC) in both seasons TPH and OC levels were slightly lower in summer than in autumn in the two environmental matrices, and the average amount of TPH in the water samples collected from all the sampling stations was generally lower than the EU standard limit of 300 μg/L However, the levels in the sediments exceeded the EGASPIN target value (50 mg/kg) for mineral oil but were below the intervention value (5,000 mg/kg), indicating a serious impact of industrial growth and urbanization on the area, although the n-alkane ratios and indexes used for source tracking revealed excessive flow from both natural and anthropogenic sources

/pdf/petroleum-hydrocarbon-fingerprints-of-water-and-sediment-31cqwh6uiq.pdf

Petroleum Hydrocarbon Fingerprints of Water and Sediment Samples of Buffalo River Estuary in the Eastern Cape Province, South Africa.

Two-dimensional barotropic hydrodynamical model ECOMSED (Estuarine Coastal and Ocean Modeling System with Sediment) developed by HydroQual, Inc., (2002) has been applied to the Estuary of Mahakam Delta, East Kalimantan, Indonesia, to study the dynamics of tide and tidal current in this region. The model was run for 15 days (27 June–12 July 2003) using river discharge and tides as generating forces. The calculated elevation and current velocity agree well with the observed elevation (maximum amplitude of about 0.6 m) and currents velocity (maximum amplitude of about 0.15 m s ) in the Mahakam Estuary. The root mean squared error in the model elevation and current velocity are 0.15 m and 0.05 m s , respectively. Wave form is changed from the mouth of the estuary to upstream. The natural oscillation period of the Mahakam Delta Tn is 19 hrs. Tn is near the period of diurnal tide and far from that of semi-diurnal tide. The decrease of semi-diurnal M2, and S2 amplitudes in the estuary is larger than that of diurnal (K1, O1) ones. The M4 tidal current amplitude follows the M2 tidal amplitude distribution, peaking at mid estuary, whereas M4 tidal elevation amplitude is greatest farther to upstream. In the Mahakam estuary, tidal elevation amplitude distortion (M4/M2) is less than 0.3. For current amplitude, M4/M2 reaches a maximum of 1.85 about 40 km from the head of the estuary. The simulation results of the hydrodynamical model show that at flood condition and highest water, the waters flow into the delta, while at ebb condition and lowest water, it flows toward the Makassar Strait.

Tide and Tidal Current in the Mahakam Estuary East Kalimantan, Indonesia

Tide and Tidal Current in the Mahakam Estuary, East Kalimantan, Indonesia

Balikpapan Bay is located in the East Borneo Province of Borneo, Indonesia and directly connected to the Makassar Strait and also has very important role in determining the dynamics of ocean current, heat and freshwater content in the Makassar Strait. Numerical model has been used to simulate the dynamic process such as the changes of water mass in the Balikpapan Bay. We have used the terrain following three-dimensional Regional Ocean Modeling System (ROMS). Tides, river discharges, and atmospheric forcing (surface fields) have been used as generating forces for the model. The model has been simulated for three months from 1 October 2012 to 1 January 2013. The model has been validated by computing the RMSE, MAPE and Willmott's index of agreement (d) using water level observation at the sampling station in Semayang port, Balikpapan. The verification showed a good agreement between model prediction and field observation data with RMSE = 7.8 cm, MAPE = 14.3% and d = 0.995 (with a value of perfect agreement equals to 1.0). The results analysed using vertical profile of salinity and temperature from 22 sampling stations with 11 stations located at the inner part of Balikpapan Bay. While the other stations located outside the Balikpapan Bay were used to analyse watermass. Water circulation is mostly dominated by the forcing from tides. The model results showed that the outer part of Balikpapan Bay is saltier than the inner part of Balikpapan bay. The highest average temperature occurred along coastal areas with value ~31 °C. The distribution of vertical salt transport showed that the water masses tend to be stratified during neap tides and mixed during spring tides condition.

https://iopscience.iop.org/article/10.1088/1755-1315/162/1/012006/pdf

The changes of water mass characteristics using 3-dimensional Regional Ocean Modeling System (ROMS) in Balikpapan bay, Indonesia

A fully three-dimensional finite difference baroclinic model system for hydrodynamics and cohesive sediment trans- port is described. The hydrodynamic model is based on the hydrostatic and Boussinesq approximations. The simulation of co- hesive sediment transport processes is performed solving the 3D-conservative advection-diffusion equation. The model is ECOMSED (Estuarine Coastal and Ocean Modeling System with Sediment) developed by HydroQual, Inc., (2002) which is ap- plied to the transport of cohesive sediments in the Mahakam Estuary, East Kalimantan, Indonesia. The model was run for 15 days (27 June-12 July 2000) driven by tidal forcing at the open boundary and river discharge at the upstream. The observed temperature, salinity, and suspended sediment data were available for the start of the simulation. Good agreement was found between model results and observed temporal and spatial variations in water elevation, currents, and suspended sediment con- centration (SSC) in the Mahakam Estuary. During the flood tidal condition, the tidal current advected the higher salinity water into the estuary, resulting in a relatively large salinity gradient inside the estuary. During the ebb tidal condition, the combined gravitational and tidal flows moved the low salinity water seaward from the upstream, leading to a rapid decrease of salinity near the mouth of the estuary. The simulation results of suspended sediment transport in the Mahakam Estuary nearly followed the salinity transport. The suspended sediments were mainly transported from Mahakam river towards Muara Pegah and Muara Jawa than Muara Berau and Muara Bayur. The SSC at Muara Jawa, Muara Pegah, and Muara Kaeli was mainly influ- enced by river discharge, meanwhile at Muara Bayur it was dominated by tidal current.

Cohesive sediment transport in the 3D- hydrodynamic-baroclinic circulation model in the Mahakam Estuary, East Kalimantan, Indonesia

The couple system between shallow water waves model (SWAN) and hydrodynamic regional ocean model (ROMS) was used to simulated the influence of waves affected by wind on sediment transport processes in the Balikpapan Bay, East Kalimantan, Indonesia. The models were simulated from 1 June 2011 to 20 June 2011. The comparison of the elevation calculated by numerical model and observation data during 14 days. Good agreement was found between model results and observed temporal and spatial variations in water elevation. The results of study showed that the highest waves height distribution located in eastern and the lowest wave height distribution located in western and in the inner of Balikpapan Bay. Whereas sediment distribution generally concentrated in the shallow water and the sediment concentration largely accumulated in the downstream of Balikpapan Bay and its surrounding coast region.

Idris Mandang

Papers

Tide and Tidal Current in the Mahakam Estuary East Kalimantan, Indonesia

Tide and Tidal Current in the Mahakam Estuary, East Kalimantan, Indonesia

The changes of water mass characteristics using 3-dimensional Regional Ocean Modeling System (ROMS) in Balikpapan bay, Indonesia

Cohesive sediment transport in the 3D- hydrodynamic-baroclinic circulation model in the Mahakam Estuary, East Kalimantan, Indonesia

A numerical simulation of wave and sediment transport in the balikpapan Bay, East Kalimantan, Indonesia