Publications by Cong Gao
POP2 Model Equation
There are 7 unknowns in the POP2, i.e., 3 velocity components: \(u,v,w\) (unit: \(m/s\)); Potential temperature: \(\theta\) (unit: \(K\)); Salinity: \(S\) (unit: dimensionless); Pressure: \(p\) (unit: \(Pa\)); Density: \(\rho\) (unit: \(kg/m^3\)). Two approximations are applied, i.e., Bossinesq approximation: density is taken as a constant exc...
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Sea Level, density and salinity
Consider a water column with a small horizontal area \(\delta A\), and its free surface height is denoted as \(\eta(t)\) over a constant depth \(H\). Therefore, the vertical length of the water column is \(\eta(t)+H\). By vertically integrating density \(\rho\) from the bottom to the surface with horizontal area \(\delta A\) multiplied, we get th...
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PO Final EXAM
1. Is Tusnami a shallow or deep water gravity waves? Write down the generation mechanism of Tsunami. 2. Is wave phase speed a vector? Is wave group speed a vector? Write down their mathematic expression. 3. The sea wave grows higher and sometimes breaks up when it gets close to the beach. Explain why. 4. Sketch and explain how Rossby wave is g...
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PO EXAM
2018 Fall Midterm Exam - Physical Oceanography 1 A parcel of water, starting at the 4000 \(m\), is adiabatically transported to the sea surface. For each of the following, circle whether the property is increased, decreased or unchanged. Write a very brief explanation for each answer. Temperature: Increased or Decreased or Unchanged Potential T...
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Ocean Model Based on Mass Conserving and Pressure Coordinates
1) Accurate simulation of salinity Volume conservation models have systematic errors in simulating salinity. The fundamental issue is that salinity is treated as a volume concentration of salt content in the ocean, in unit of \(kg/m^3\). However, in oceanography salt content is denfined in terms of mass concentration, i.e., \(g/kg\). These two va...
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Disaster by Boussinesq approximation
Let us consider a simple and rather idealized condition with uniform heating: Hydrostatic balance \(-\frac{\partial p}{\partial z} - \rho g=0\) No viscosity \(\mu_H=\mu_V=0\) Gradient in horizontal direction of any variable is zero \(\frac{\partial }{\partial x}=\frac{\partial }{\partial y}=0\) Horizontal velocity is zero \(u=v=0\) Density is on...
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