Nomenclature: Difference between revisions
From Atomix
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| zonal velocity | | zonal velocity | ||
| eastward_velocity | | eastward_velocity | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|NORTH_VEL | |NORTH_VEL | ||
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| meridional velocity | | meridional velocity | ||
| northward_velocity | | northward_velocity | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|UP_VEL | |UP_VEL | ||
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| vertical velocity | | vertical velocity | ||
| upward_velocity | | upward_velocity | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|ERROR_VEL | |ERROR_VEL | ||
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| error velocity | | error velocity | ||
| error_velocity | | error_velocity | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|U_VEL | |U_VEL | ||
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| velocity parellel to mean flow | | velocity parellel to mean flow | ||
| meanflow_velocity | | meanflow_velocity | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|V_VEL | |V_VEL | ||
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| velocity perpendicular to mean flow | | velocity perpendicular to mean flow | ||
| crossflow_velocity | | crossflow_velocity | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|Drop_Speed | |Drop_Speed | ||
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| Profiler fall speed | | Profiler fall speed | ||
| mean_drop_speed | | mean_drop_speed | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|FlowPast_Speed | |FlowPast_Speed | ||
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| Flow speed past sensor | | Flow speed past sensor | ||
| mean_velocity_past_turbulence_sensor | | mean_velocity_past_turbulence_sensor | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|AlongBeam_Velocity | |AlongBeam_Velocity | ||
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| Along-beam velocity from acoustic Doppler sensor | | Along-beam velocity from acoustic Doppler sensor | ||
| observed_velocity_along_an_acoustic_beam | | observed_velocity_along_an_acoustic_beam | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|AlongBeam_Residual_Velocity | |AlongBeam_Residual_Velocity | ||
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| Along-beam velocity from acoustic Doppler sensor with background flow deducted | | Along-beam velocity from acoustic Doppler sensor with background flow deducted | ||
| residual_velocity_along_an_acoustic_beam | | residual_velocity_along_an_acoustic_beam | ||
| | | <math>\mathrm{m\, s^{-1}}</math> | ||
|- | |- | ||
|Vertical_Bin_Size | |Vertical_Bin_Size | ||
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| Vertical size of measurement bin for acoustic Doppler sensor | | Vertical size of measurement bin for acoustic Doppler sensor | ||
| vertical_bin_size | | vertical_bin_size | ||
| m | | <math>\mathrm{m}</math> | ||
|- | |- | ||
|AlongBeam_Distance | |AlongBeam_Distance | ||
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| Along-beam distance from acoustic Doppler sensor | | Along-beam distance from acoustic Doppler sensor | ||
| distance_along_an_acoustic_beam | | distance_along_an_acoustic_beam | ||
| m | | <math>\mathrm{m}</math> | ||
|- | |- | ||
|AlongBeam_Bin_Size | |AlongBeam_Bin_Size | ||
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| Along-beam bin size for acoustic Doppler sensor | | Along-beam bin size for acoustic Doppler sensor | ||
| bin_size_along_an_acoustic_beam | | bin_size_along_an_acoustic_beam | ||
| m | | <math>\mathrm{m}</math> | ||
|- | |- | ||
|Beam_Angle | |Beam_Angle |
Revision as of 17:14, 23 April 2021
Frame of reference
- Define frame of reference, and notation. Use u,v,w and x,y, and z?
- Dumping a sketch would be useful
Reynold's Decomposition
- Variable names for Decomposition of total, mean, turbulent and waves.
Background (total) velocity
Parameter name | Symbol | Description | Standard long name | Units |
---|---|---|---|---|
EAST_VEL | [math]\displaystyle{ u }[/math] | zonal velocity | eastward_velocity | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
NORTH_VEL | [math]\displaystyle{ v }[/math] | meridional velocity | northward_velocity | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
UP_VEL | [math]\displaystyle{ W }[/math] | vertical velocity | upward_velocity | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
ERROR_VEL | [math]\displaystyle{ u_e }[/math] | error velocity | error_velocity | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
U_VEL | [math]\displaystyle{ U }[/math] | velocity parellel to mean flow | meanflow_velocity | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
V_VEL | [math]\displaystyle{ V }[/math] | velocity perpendicular to mean flow | crossflow_velocity | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
Drop_Speed | [math]\displaystyle{ W_d }[/math] | Profiler fall speed | mean_drop_speed | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
FlowPast_Speed | [math]\displaystyle{ U_P }[/math] | Flow speed past sensor | mean_velocity_past_turbulence_sensor | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
AlongBeam_Velocity | [math]\displaystyle{ b }[/math] | Along-beam velocity from acoustic Doppler sensor | observed_velocity_along_an_acoustic_beam | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
AlongBeam_Residual_Velocity | [math]\displaystyle{ b^{\prime} }[/math] | Along-beam velocity from acoustic Doppler sensor with background flow deducted | residual_velocity_along_an_acoustic_beam | [math]\displaystyle{ \mathrm{m\, s^{-1}} }[/math] |
Vertical_Bin_Size | [math]\displaystyle{ \delta{z} }[/math] | Vertical size of measurement bin for acoustic Doppler sensor | vertical_bin_size | [math]\displaystyle{ \mathrm{m} }[/math] |
AlongBeam_Distance | [math]\displaystyle{ r }[/math] | Along-beam distance from acoustic Doppler sensor | distance_along_an_acoustic_beam | [math]\displaystyle{ \mathrm{m} }[/math] |
AlongBeam_Bin_Size | [math]\displaystyle{ \delta{r} }[/math] | Along-beam bin size for acoustic Doppler sensor | bin_size_along_an_acoustic_beam | [math]\displaystyle{ \mathrm{m} }[/math] |
Beam_Angle | [math]\displaystyle{ \theta }[/math] | Beam transmit and receive angle relative to instrument axis for acoustic Doppler sensor | acoustic_beam_angle | degree |
Turbulence properties
Parameter name | Symbol | Description | Standard long name | Eqn | Units |
---|---|---|---|---|---|
EPSI | [math]\displaystyle{ \varepsilon }[/math] | Turbulent kinetic energy dissipation rate | tke_dissipation | [math]\displaystyle{ \mathrm{W\, kg^{-1}} }[/math] | |
RI | [math]\displaystyle{ Ri }[/math] | Richardson number | richardson_number | [math]\displaystyle{ Ri = \frac{N^2}{S^2} }[/math] | |
RI_F | [math]\displaystyle{ Ri_f }[/math] | Flux gradient Richardson number | flux_grad_richardson_number | [math]\displaystyle{ \frac{B}{P} }[/math] or Ivey & Immerger? Karan et cie | |
Krho | [math]\displaystyle{ \kappa_\rho }[/math] | Turbulent diffusivity | turbulent_diffusivity | [math]\displaystyle{ \kappa = \Gamma \varepsilon N^{-2} }[/math] | [math]\displaystyle{ \mathrm{m^2\, s^{-1}} }[/math] |
DLL | [math]\displaystyle{ D_{LL} }[/math] | Second-order longitudinal structure function | second_order_longitudinal_structure_function | [math]\displaystyle{ D_{LL} = \big\langle[b^{\prime}(r) - b^{\prime}(r+n\delta{r})]^2\big\rangle }[/math] | m[math]\displaystyle{ ^2 }[/math]s[math]\displaystyle{ ^{-2} }[/math] |
Fluid properties and background gradients for turbulence calculations
Parameter Name | Symbol | Description | Standard long name | Eqn | Units |
---|---|---|---|---|---|
S | [math]\displaystyle{ S }[/math] | Background velocity shear | background_velocity_shear | [math]\displaystyle{ S = \left( \left( \frac{\partial U}{\partial z}\right)^2 + \left( \frac{\partial V}{\partial z}\right)^2 \right)^{1/2} }[/math] | s[math]\displaystyle{ ^{-1} }[/math] |
KVISC35 | [math]\displaystyle{ \nu }[/math] | Kinematic viscosity of water for seawater at 35 and 20 [math]\displaystyle{ ^o }[/math]C | seawater_kinematic_viscosity_at_35psu | [math]\displaystyle{ 1\times 10^{-6} }[/math] | m2/s |
N | [math]\displaystyle{ N }[/math] | Background stratification, i.e buoyancy frequency | background_buoyancy_frequency | [math]\displaystyle{ N = \sqrt{\frac{-g}{\bar{\rho}} \frac{\partial\bar{\rho}}{\partial z}} }[/math] | rad/s |
Theoretical Length and Time Scales
Parameter | Symbol | Description | Standard long name | Eqn | Units |
---|---|---|---|---|---|
T_N | [math]\displaystyle{ \tau_N }[/math] | Buoyancy timescale | buoyancy_time_scale | [math]\displaystyle{ \tau_N = \frac{2\pi}{N} }[/math] | s |
L_E | [math]\displaystyle{ L_E }[/math] | Ellison length scale (limit of vertical displacement without irreversible mixing) | Eliison_lenght_scale | [math]\displaystyle{ L_E=\frac {\langle \rho'^2\rangle^{1/2}}{\partial \overline{\rho}/\partial z} }[/math] | m |
L_RHO | [math]\displaystyle{ L_\rho }[/math] | Density length scale | density_length_scale | [math]\displaystyle{ L_\rho }[/math] | m |
L_S | [math]\displaystyle{ L_S }[/math] | Corssin length scale | Corssin_shear_length_scale | [math]\displaystyle{ L_S = \sqrt{\varepsilon/S^3} }[/math] | m |
L_K | [math]\displaystyle{ \eta }[/math] | Kolmogorov length scale (smallest overturns) | Kolmogorov_length_scale | [math]\displaystyle{ \eta=\left(\frac{\nu^3}{\varepsilon}\right)^{1/4}=\frac{1}{2\pi\hat{k}_K} }[/math] | m |
L_O | [math]\displaystyle{ L_o }[/math] | Ozmidov length scale, measure of largest overturns in a stratified fluid | Ozmidov_stratification_length_scale | [math]\displaystyle{ L_o=\left(\frac{\varepsilon}{N^3}\right)^{1/2} }[/math] | m |
L_T | [math]\displaystyle{ L_T }[/math] | Thorp length scale | Thorpe_stratification_length_scale | [math]\displaystyle{ L_T }[/math] | m |
Turbulence Spectrum
Taylor's Frozen Turbulence for converting temporal to spatial measurements [math]\displaystyle{ \left(\bar{u}_1\frac{\partial }{\partial{x}} = \frac{\partial}{\partial{t}}\right) }[/math]
- Missing the y-axi variable. CEB proposes:
- [math]\displaystyle{ \Psi_{variable} }[/math] for model/theoretical spectrum of variable e.g., du/dx or u
- [math]\displaystyle{ \Phi_{variable} }[/math] for observed spectrum of variable e.g., du/dx or u
- Lowest frequency and wavenumber resolvable
Symbol | Description | Eqn | Units |
---|---|---|---|
[math]\displaystyle{ \Delta t }[/math] | Sampling interval | [math]\displaystyle{ \frac{1}{f_s} }[/math] | s |
[math]\displaystyle{ \Delta s }[/math] | Sampling volume dimension | m | |
[math]\displaystyle{ f }[/math] | Frequency | [math]\displaystyle{ \frac{\omega}{2\pi} }[/math] | Hz |
[math]\displaystyle{ f_n }[/math] | Nyquist frequency | [math]\displaystyle{ f_n=0.5f_s }[/math] | Hz |
[math]\displaystyle{ f_s }[/math] | Sampling frequency | [math]\displaystyle{ f_s=\frac{1}{\Delta t} }[/math] | Hz |
[math]\displaystyle{ k }[/math] | Wavenumbers (angular) | [math]\displaystyle{ k=\frac{f}{\bar{u}}=2\pi\hat{k} }[/math] | rad/m |
[math]\displaystyle{ \hat{k} }[/math] | Wavenumbers | [math]\displaystyle{ \hat{k}=\frac{k}{2\pi} }[/math] | cpm |
[math]\displaystyle{ \hat{k}_\Delta }[/math] | Nyquist wavenumber, based on sampling volume's size [math]\displaystyle{ \Delta l }[/math] | [math]\displaystyle{ \hat{k}_\Delta=\frac{0.5}{\Delta l} }[/math] | cpm |
[math]\displaystyle{ \hat{k}_n }[/math] | Nyquist wavenumber, via Taylor's hypothesis (temporal measurements) | [math]\displaystyle{ \hat{k}_n=\frac{f_n}{u} }[/math] | cpm |
[math]\displaystyle{ \omega }[/math] | Angular frequency | [math]\displaystyle{ 2\pi f }[/math] | rad/s |
Supplementary Data required for computing Turbulence
Channel | Shear Probes | ADCP | ADVs |
---|---|---|---|
Ax | x | x | x |
Ay | x | x | x |
Az | x | x | x |