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C $Header: /u/gcmpack/MITgcm/pkg/sbo/sbo_calc.F,v 1.13 2009/04/28 18:45:22 jmc Exp $ |
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C $Name: $ |
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#include "SBO_OPTIONS.h" |
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CBOP |
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C !ROUTINE: SBO_CALC |
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C !INTERFACE: ========================================================== |
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SUBROUTINE SBO_CALC( myTime, myIter, myThid ) |
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C !DESCRIPTION: \bv |
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C /==========================================================\ |
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C | SUBROUTINE SBO_CALC | |
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C | o Do SBO diagnostic output. | |
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C |==========================================================| |
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C | NOTE: The following subtleties are ignored for time | |
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C | being but may need revisiting at some point in time. | |
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C | 1) The model is volume-preserving and Boussinesq so | |
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C | quantities like oceanic mass need to be interpreted | |
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C | with some care. | |
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C | 2) The sea surface height variable etaN lags other | |
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C | prognostic variables by half a time step. This lag | |
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C | is ignored in SBO computations. | |
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C | 3) Density is computed using function SBO_RHO which is | |
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C | not exaclty equivalent to the model s FIND_RHO. | |
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C \==========================================================/ |
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IMPLICIT NONE |
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|
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C======================================================================= |
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C |
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C Written by Richard Gross (Richard.Gross@jpl.nasa.gov) |
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C June 10, 2001: Modified for online computations in MIT GCM UV |
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C by Dimitris Menemenlis (Menemenlis@jpl.nasa.gov) |
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C |
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C Purpose |
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C calc_sbo calculates the core products of the IERS Special Bureau |
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C for the Oceans including oceanic mass, center-of-mass, angular |
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C momentum, and bottom pressure. |
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C |
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C Usage |
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C 1. calc_sbo must be called, and the results saved, at each time step |
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C in order to create a time series of the IERS SBO core products |
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C 2. it is suggested that after the time series have been generated |
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C and before saving the results to a file, time-mean values be |
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C computed and removed from all of the calculated core products |
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C and that the mean values be reported along with the demeaned |
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C time series |
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C |
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C Availability |
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C ftp://euler.jpl.nasa.gov/sbo/software/calc_sbo.f |
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C |
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C Reference |
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C Gross, R. S., F. O. Bryan, Y. Chao, J. O. Dickey, S. L. Marcus, |
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C R. M. Ponte, and R. Tokmakian, The IERS Special Bureau for the |
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C Oceans, in IERS Technical Note on the IERS Global Geophysical |
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C Fluids Center, edited by B. Chao, in press, Observatoire de Paris, |
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C Paris, France, 2000. |
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C |
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C Required inputs |
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C gridded values of horizontal velocity (u,v), temperature, |
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C salinity, and sea surface height along with the latitude, |
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C and longitude of the grid points and the thicknesses of the |
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C vertical layers |
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C |
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C External routines called by calc_sbo |
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C real function rho1(s, t) |
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C returns density of sea water given salinity s and temperature t |
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C (a default version of rho1 has been included with calc_sbo, |
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C however in general this should be replaced by a function that |
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C returns the density of the model ocean so that the same density |
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C as the model s is used to compute the sbo products) |
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C |
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C Assumptions |
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C 1. the input velocity, temperature, salinity, and sea surface |
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C height fields are assumed to be defined on the same grid |
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C 2. the horizontal grid is assumed to be equally spaced in |
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C latitude and longitude |
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C 3. land is flagged in the input quantities by a salinity or |
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C temperature value greater than or equal to 999.99 |
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C 4. input quantities are assumed to have the following units: |
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C salinity (s) parts per thousand |
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C temperature (t) degrees centigrade |
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C eastwards velocity (u) centimeters per second |
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C northwards velocity (v) centimeters per second |
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C sea surface height (ssh) meters |
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C latitude of grid point degrees N |
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C longitude of grid point degrees E |
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C thickness of layer meters |
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C 5. input quantities are passed to calc_sbo via common blocks |
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C /ogcm/ and /vgrid/ |
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C 6. land is flagged in the output ocean-bottom pressure (obp) |
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C by a value of -999.99 |
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C 7. calulated products have the units: |
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C mass of oceans (mass) kilograms (kg) |
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C center-of-mass of oceans (com) meters (m) |
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C oceanic angular momentum (oam) kg-m**2/second |
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C ocean-bottom pressure (obp) Pascals (Newton/m**2) |
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C 8. calculated products are passed out of calc_sbo via common |
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C block /sbo/ |
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C 9. the sea surface height layer is assumed to have the same |
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C velocity, temperature, and salinity as the first depth layer |
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C |
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C For questions regarding calc_sbo or the IERS SBO, please contact: |
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C Richard Gross Richard.Gross@jpl.nasa.gov |
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C Jet Propulsion Laboratory ph. +1 818-354-4010 |
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C Mail Stop 238-332 fax +1 818-393-6890 |
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C 4800 Oak Grove Drive |
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C Pasadena, Ca 91109-8099 |
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C USA |
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C |
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C======================================================================= |
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C \ev |
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C !USES: =============================================================== |
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C === Global variables === |
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "GRID.h" |
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#include "DYNVARS.h" |
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#include "FFIELDS.h" |
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#include "SBO.h" |
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C !INPUT PARAMETERS: =================================================== |
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C == Routine arguments == |
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C myTime :: Current time of simulation ( s ) |
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C myIter :: Iteration number |
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C myThid :: Number of this instance of SBO_CALC |
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_RL myTime |
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INTEGER myIter, myThid |
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#ifdef ALLOW_SBO |
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C !LOCAL VARIABLES: ==================================================== |
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C external function called by calc_sbo |
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C returns density of sea water |
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_RL rhoK(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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C internal variables |
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C bi, bj :: array indices |
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C i :: index over longitude grid points |
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C j :: index over latitude grid points |
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C k :: index over layers |
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C lat :: latitude of grid point (radians) |
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C lat_deg :: latitude of grid point (degrees) |
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C lon :: longitude of grid point (radians) |
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C radius :: radius of bottom of layer (m) |
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C darea :: element of surface area (unit radius) |
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C dradius :: element of radius (m) |
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C dvolume :: element of volume (m**3) |
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C s :: salinity at grid point (ppt) |
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C t :: temperature at grid point (deg C) |
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C u :: eastward velocity at grid point (m/s) |
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C v :: northward velocity at grid point (m/s) |
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C density :: density at grid point (kg/m**3) |
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C ae :: earth s mean radius (m) (PREM value) |
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C grav :: earth s mean gravity (m/s**2) (PREM) |
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C sbo_omega :: earth s mean angular velocity (rad/s) |
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integer bi, bj, i, j, k, kn0 |
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_RL lat, lat_deg, lon, radius, darea, dradius, dvolume, depth |
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_RL u, v, density |
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_RL ae, grav, sbo_omega |
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PARAMETER ( ae = 6.3710 _d 6 ) |
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PARAMETER ( grav = 9.8156 ) |
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PARAMETER ( sbo_omega = 7.292115 _d -5 ) |
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CEOP |
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C initialize variables to be computed |
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xoamc = 0.0 |
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yoamc = 0.0 |
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zoamc = 0.0 |
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xoamp = 0.0 |
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yoamp = 0.0 |
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zoamp = 0.0 |
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mass = 0.0 |
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xcom = 0.0 |
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ycom = 0.0 |
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zcom = 0.0 |
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sbobp = 0.0 |
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sboarea = 0.0 |
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sboempmrwet = 0.0 |
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sboqnetwet = 0.0 |
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DO bj = myByLo(myThid), myByHi(myThid) |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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DO j = 1-OLy, sNy+OLy |
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DO i = 1-OLx, sNx+OLx |
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obp(i,j,bi,bj) = 0.0 |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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C loop over all grid points, accumulating mass, com, oam, and obp |
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DO bj = myByLo(myThid), myByHi(myThid) |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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DO k = 0, Nr |
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kn0 = max(k,1) |
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CALL FIND_RHO_2D( |
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I 1, sNx, 1, sNy, kn0, |
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I theta(1-OLx,1-OLy,kn0,bi,bj), |
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I salt(1-OLx,1-OLy,kn0,bi,bj), |
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O rhoK, |
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I kn0, bi, bj, myThid ) |
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C-- |
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DO j = 1, sNy |
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DO i = 1, sNx |
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IF ( maskC(i,j,kn0,bi,bj) .NE. 0. ) THEN |
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C latitude (rad) |
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lat_deg = yC(i,j,bi,bj) |
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lat = yC(i,j,bi,bj) * pi / 180.0 |
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C longitude (rad) |
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lon = xC(i,j,bi,bj) * pi / 180.0 |
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C unit radius : should be using rA like this: |
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c darea = rA(i,j,bi,bj)*maskC(i,j,kn0,bi,bj) /ae/ae |
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darea = dyF(i,j,bi,bj) * dxF(i,j,bi,bj) / ae / ae |
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& * maskC(i,j,kn0,bi,bj) |
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|
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IF ( k .EQ. 0 ) THEN |
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sboarea = sboarea + darea |
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sboempmrwet = sboempmrwet + empmr(i,j,bi,bj)*darea |
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sboqnetwet = sboqnetwet + qnet(i,j,bi,bj) *darea |
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C k=0 => ssh |
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radius = ae |
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dradius = etaN(i,j,bi,bj) * maskC(i,j,kn0,bi,bj) |
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|
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ELSE |
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C-- k > 0 |
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C radius to center of cell (m) |
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radius = ae - ABS(rC(k)) |
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dradius = drF(k) * maskC(i,j,k,bi,bj) |
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C-- end of k-if |
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ENDIF |
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|
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cph s = salt(i,j,kn0,bi,bj) |
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cph t = theta(i,j,kn0,bi,bj) |
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u =(uvel(i,j,kn0,bi,bj)+uvel(i+1,j,kn0,bi,bj))*0.5 _d 0 |
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v =(vvel(i,j,kn0,bi,bj)+vvel(i,j+1,kn0,bi,bj))*0.5 _d 0 |
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C cell volume (m**3) |
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dvolume = darea * radius**2 * dradius |
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C get density |
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depth = ae - radius |
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cph( |
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cph compute density consistent with EOS used by model |
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cph density = sbo_rho(depth,lat_deg,s,t) |
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density = rhoConst + rhoK(i,j) |
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cph) |
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C accumulate mass of oceans |
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mass = mass + density * dvolume |
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C accumulate center-of-mass of oceans |
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xcom = xcom + density * COS(lat) * COS(lon) |
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& * radius * dvolume |
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ycom = ycom + density * COS(lat) * SIN(lon) |
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& * radius * dvolume |
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zcom = zcom + density * SIN(lat) |
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& * radius * dvolume |
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C accumulate oceanic angular momentum due to currents |
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xoamc = xoamc + ( v*SIN(lon)-u*SIN(lat)*COS(lon)) |
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& * density * radius * dvolume |
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yoamc = yoamc + (-v*COS(lon)-u*SIN(lat)*SIN(lon)) |
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& * density * radius * dvolume |
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zoamc = zoamc + u*COS(lat) |
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& * density * radius * dvolume |
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C accumulate oceanic angular momentum due to pressure |
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xoamp = xoamp - SIN(lat) * COS(lat) * COS(lon) |
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& * sbo_omega * density * radius*radius * dvolume |
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yoamp = yoamp - SIN(lat) * COS(lat) * SIN(lon) |
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& * sbo_omega * density * radius*radius * dvolume |
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zoamp = zoamp + COS(lat)**2 |
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& * sbo_omega * density * radius*radius * dvolume |
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|
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C accumulate ocean-bottom pressure |
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obp(i,j,bi,bj) = obp(i,j,bi,bj) |
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& + grav * density * dradius |
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C end if wet |
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ENDIF |
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C end loop over i,j |
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ENDDO |
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ENDDO |
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C end loop over k |
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ENDDO |
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C accumulate for global-mean ocean-bottom pressure |
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DO j = 1, sNy |
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DO i = 1, sNx |
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sbobp = sbobp + obp(i,j,bi,bj)*rA(i,j,bi,bj) |
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ENDDO |
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ENDDO |
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C end loop over bi,bj |
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ENDDO |
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ENDDO |
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|
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C sum all values across model tiles |
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C- note: GLOBAL_SUM applied to var. in common block <= wrong if Muti-threaded |
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_GLOBAL_SUM_RL( mass , myThid ) |
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_GLOBAL_SUM_RL( xcom , myThid ) |
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_GLOBAL_SUM_RL( ycom , myThid ) |
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_GLOBAL_SUM_RL( zcom , myThid ) |
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_GLOBAL_SUM_RL( xoamc , myThid ) |
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_GLOBAL_SUM_RL( yoamc , myThid ) |
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_GLOBAL_SUM_RL( zoamc , myThid ) |
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_GLOBAL_SUM_RL( xoamp , myThid ) |
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_GLOBAL_SUM_RL( yoamp , myThid ) |
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_GLOBAL_SUM_RL( zoamp , myThid ) |
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cph( |
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_GLOBAL_SUM_RL( sbobp, myThid ) |
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_GLOBAL_SUM_RL( sboarea, myThid ) |
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_GLOBAL_SUM_RL( sboempmrwet, myThid ) |
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_GLOBAL_SUM_RL( sboqnetwet, myThid ) |
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cph) |
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|
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C finish calculating center-of-mass of oceans |
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xcom = xcom / mass |
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ycom = ycom / mass |
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zcom = zcom / mass |
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cph( |
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c sbobp = sbobp / sboarea |
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sbobp = sbobp / globalArea |
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sboempmrwet = sboempmrwet / sboarea |
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sboqnetwet = sboqnetwet / sboarea |
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cph) |
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|
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#endif /* ALLOW_SBO */ |
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|
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RETURN |
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END |
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