2N 140W work

2°N, 140°W work

    First-day plots:

  1. Velocity:
    1. Vectors: Obs    Differences from 5m values   Difference from vertical mean
      Overlay 5m and 25m velocity
    2. Zonal component: Obs   Difference from 5m values   Difference from vertical mean
    3. Meridional component: Obs   Difference from 5m values   Difference from vertical mean   Time series
    4. u and v at 5m
    5. Current direction: Differences from 5m values

  2. Various checks and comparisons:
    1. Wind components
    2. SST, winds, currents
    3. Zonal winds and meridional current
    4. Temperature: Compare TAO   Difference from 1m value   Difference from vertical mean
    5. Checking construction of daily averages: Accumulation of missing values   Sep-Oct   Sep 10 u interpolation   Sep 10 v   

    6. Temperature correction (finally done 15 June 07):
      1. Time series of correction at each depth
      2. Mean correction each depth
        ==>> Plots below are noted "Corrected T°" if made with the new temps.
      3. See section 9 below for the original temperature time series and diagnosis that led to correction.

    Subsequent work ....

     Note: In interpreting plots showing velocities relative to 25m, keep in mind that v(25m) changed character around 25 Oct 2004. See v difference from vertical mean (Fig.1c) above. The u component did not have a similar change. What does this mean?

  3. Available u, v, T:
    1. Summary fill plots
    2. Documenting the short gaps:
      1. (u,v) (combined)
        (u and v have the same gaps, but in some cases the gap may be relevant to resolving the diurnal cycle, so both are of interest)
      2. Met
      3. Temperature

  4. Various ways to present the time series of winds, current, temperature:
    1. Total currents: Color-filled T   (same but with N up, E right)   SST line plot
    2. Currents relative to 25m: Color-filled T   (same but with N up, E right)   SST line plot
    3. Relative to 20m   Detail of 1-17 December
    4. Add geostrophic currents from TMI SST (see TMI section below for description):
      ug   u-ug   7-day filter

  5. Time series of 5m u and v (daily)

  6. Diurnal cycle:
    Note that most of these (all the old ones) show shear rel 25m averaged over the whole period. Since we now know that the 25m Sontek crapped out after 7 Oct, these are wrong! See the new ones in 6.b.4 for correct vectors.
    1. Temperature:   Temperature     T difference from 5m     Demeaned diurnal T(z)
      Checks (examples):   25th day of each month:   May-Sep   Oct-Feb   3-day chunks:   May-Sep   Oct-Feb
    2. Velocity
      1. Time series of diurnal u and v at 5m:   Values   Anomalies    
      2. Overlay 5m and 25m:   Values   Anomalies
      3. Vectors: (These have conventional orientation (N up, E to right) unless noted on plot)
        1. Reference (vectors and components)   Demeaned
        2. Anomalies
        3. Vectors relative to 5m
        4. Vectors relative to 25m
        5. Vectors rel 25m with overlaid temperature
        6. Some combinations for choosing among alternatives: West up, north to right   North up, east to right
        7. Winds,temperature and wind/current components
      4. Find that the 25m CM failed on 7 Oct 2004. Comparisons showing that and consequences:
        1. Vectors rel 25m before and after Oct failure:   2 plots   Overlaid   Demeaned
          (These are primarily of historical interest to document the failure)
          (last 2 of the above plots have wrong labels for wind scale vector: should be 5 m/s)
        2. Resolve above confusion, correct plots are rel 25m to 7 Oct, or rel 20m for the whole period:
             Measured and ageostrophic shear vectors:
          1. Comparisons of 20 vs 25m, and part and whole period:
            T and shear rel 20 and 25m (before and after 7 Oct)   Overlaid shears different depths and times
          2. Rel 20m, whole period   To 7 Oct
          3. Rel 25m, to 7 Oct   Overlay 20 and 25m vectors to 7 Oct
      5. Final (correct) shear plots are rel 25m, to 7 Oct:
        T and 25m shear   Wind, u, uag vectors
    3. Met variables   Wind and 5m current components overlaid
    4. N-squared and shear-squared   Ri
    5. Line plots
      1. T(z): 5, 10, 15, 25m   Delta-t between 5 and 25m
      2. Velocity components and speed
      3. Winds: Wind components and speed   (Separate panels)
    6. Diurnal cycle stack plots (Wind, u and uag = Ekman spiral and homogenizing? NO!):
      1. Night   Afternoon
      2. Movie of hourly velocities    (although the mathematical construct of ug and uag in these plots is not useful for the diurnal cycle, because the adjustment to the pressure gradient takes longer than a day, the changes in total u remain relevant, and show the nightly homogenization and consequent reduced shear, and the afternoon restratification, when the velocities become strongly sheared downwind.)

  7. Mixed layer:
    1. Histograms of T(1m) - T(25m):   Percent   Log # of occurrences
    2. Also see plots from standard TAO in 13b below.

  8. Mean and RMS shear:  
    1. u,v   Shear
    2. Use only data before 10 Oct 2004: u,v   Shear
    3. Mean u and v comparing 2 periods (include table of mean values)
    4. Also see mean profiles in 15.e.1 below (include u_g)

  9. Checking the T calibration:
    1. T differences among adjacent depths
    2. Examples (details): Temperature   N-squared

    3. Histograms of N-squared: All depths grouped   Overlaid depths
    4. See section 2f above for the corrections made.

  10. Rotating velocity to wind:
    1. Whole time series
    2. Details (2-month chunks): Jun-Jul 2004   Aug-Sep   Oct-Nov   Dec-Jan 2005   Jan-Feb 2005
    3. Diurnal cycle rel 25m (meaningless)

  11. Stack plots of wind and currents at a particular date
    1. Mean currents:
      1. Stack of mean winds and velocity (rel 25m)   Overlay total currents   
      2. Relative to 20m   Example on 10 Nov   Relative to 5m
      3. With 2° SST gradient: ug   uag
    2. Total currents: May-Aug   Aug-Nov   Nov-Feb
    3. Currents rel. 25m: May-Aug   Aug-Nov   Nov-Feb
    4. Currents rel. 20m: May-Aug   Aug-Nov   Nov-Feb
    5. (These were made with Fusion TMI SST)
      Currents rel. 20m with overlaid SST gradient (1/4° differences): May-Aug   Aug-Nov   Nov-Feb
      Currents rel. 20m with overlaid SST gradient (fitted line): May-Aug   Aug-Nov   Nov-Feb
    6. Diurnal cycle anomalies
  12. Ekman transport (and interannual variability):
    (Includes some u_ag plots incorporating TMI SST gradients)
    1. Time series of meridional Ekman and total transport    (Corrected)
      Also compare Ekman at 5°N  (Use standard TAO winds)
    2. Check 2°N,140°W winds against climatology:
      1. Buoy and QuikSCAT stress and climatology
      2. V_Ek from mooring and ERS winds   
    3. ERS total V_Ek
    4. Schematic Ekman shears
    5. Checking interannual variability (how typical was this period?):
      Zonal wind: 1987-2006   9-month period   Dailies vs climatology
    6. Ekman spirals (u_ag):   Rel.25m (nice one)
      Rel.20m:   May-Oct   Oct-Feb   Whole period
      Mean spiral rel 25m when r_s modifies PG flow as well
      => (Also see profiles of u, ug, uag in Figs.15.e.1, and related plots in 15.i and 15.h below)
    7. Ekman and modifed Ekman (Wittenberg) transport time series
    8. Meridional shear transport time series (Includes v_ag from both ordinary and r_s-rotated u_g)
  13. Standard TAO T and stratification:
    1. Z20 and SST
    2. Near-surface temperatures (ML?):
      Time series of T   T-SST   Detail   Depth of SST-0.5,0.2,0.1°C
  14. Scatter plots (stress and stratification vs shear):
    1. Scatter plot of stress vs shear   Better version   
    2. Windspeed vs ageostrophic shear
    3. Shear vs stratification   Nov-Feb only
    4. (Also see scatter plots of shear vs wind and SST in 16 below)

  15. Finding the SST gradient from TMI (daily, 1/4°)
    ==>>   This section includes everything that involves u_g due to the SST front!
    (A few exceptions include the "Ekman spirals" involving u_ag with the other Ekman stuff in 12 above)

    (Lots of confusion about TMI products. The "fusion" product seems to have a significant lag compared to buoy SST. The APDRC 3-day-running mean product is better (still a lag of a little less than a day. Earlier plots here are fusion, plots after about 5 April 2007 are APDRC. Hopefully the labels reflect this! However, for many purposes the lag makes no difference. It really matters only when comparing the phase with buoy values; the statistics and values of the two TMI products are very similar.)

    Note that the TMI SST is to nearest 0.05°C: gradient can be funky .... see examples below

    1. TMI grid structure (on 1/4°, not on integer degrees (interpolation necessary ....): 
      Over mean SST   Over 10 Nov 2004 SST
    2. Examples of SST gradient: 
      1. Meridional: 5-day averages   Daily values
      2. Zonal: 5-day averages   Daily values
    3. 1.4Mb movie of TMI SST near 2°N,140°W
    4. Compare the gradient found between gridpoints nearest to 2°N,140°W (1/4° differencing) vs a best-fit line:
      Examples: 10th day of each month, June 04 through Feb 05:
      1. d(SST)/dx: Jun   Jul   Aug   Sep   Oct   Nov   Dec   Jan   Feb   
      2. d(SST)/dy: Jun   Jul   Aug   Sep   Oct   Nov   Dec   Jan   Feb   
      3. Example of Ty/Tx (Note that only a few discrete values occur)
      4. SST gradient, Shear and Wind overlaid on SST map:
        1. 1/4° differencing: Jun   Jul   Aug   Sep   Oct   Nov   Dec   Jan   Feb   
        2. Fitted line:          Jun   Jul   Aug   Sep   Oct   Nov   Dec   Jan   Feb   
        3. Maps at 3-day intervals (corresponding to stackplots in 11e above):
          Group: 1   2   3   4   4   5   6   7   8   9   All together on one page
      5. See stackplots including these gradients (plots 11e above)
      6. Directions of wind, shear, and SST gradient
        1. Directions
        2. Difference from Shear direction: V1   From smoothed differences
        3. High-passed differences
        4. Example of shear, wind SST gradient on 22 Aug
      7. Compare 1/4° fitting to 2° fitting (APDRC) (Meghan insisted!)
    5. Use the SST gradient to compute ug. (Linear eqn of state, thermal wind to find ug(z=0) relative to 20m.)
      1. Mean u,ug,u-ug components:
        1. Rel. 20m:   Whole period (original TMI)   Whole period (APDRC SST)   May-Oct
        2. Rel. 25m:   May-Oct
      2. u and v components: Unsmoothed   5-day triangle   Overlay SST   5-day filter
      3. Note the 0.05°C steps mean there are few possible vector angles
      4. ug overlaid on SST(y,t): Unsmoothed   5-day filter
      5. ug overlaid on obs currents: ug   u-ug   7-day filter
      6. TMI gradients: Components   Magnitude
    6. Examples (many examples) showing measured and geostrophic shear, over SST (APDRC)
    7. Is the shear downwind?
      (Comparison between measured shear and geostrophic-adjusted shear vs wind)
    8. Mean shear: u,ug,uag, and wind:   Vectors   Variance ellipses   Over map of SST   
      Overlay 10, 15, 20m shear   5,10,15,25m rel 5m (til 15 Oct)
    9. Wind, ug, uag shear (When does uag tilt the front?)
      1. Shear rel 10m   Overlay both
      2. Relative directions of wind/uag/front:   Scatter diagram of wind/uag angle difference   Time series of angles
      3. Index of warm-over-cold tilting:   time series   Compare stratification
    10. SST advection terms:   7-day RM   31-day RM
      7-day RM, 1°-gradient Grad(SST)

  16. Scatter plots (inspired by Santiago and Firing):
    1. Shear vs wind, a la Santiago and Firing: Direction   Magnitude
    2. Include u-ug: Direction   Magnitude   Direction (2° SST gradient)
    3. Shear vs SST   Shear vs d(SST)/dt   Nov-Feb only
    4. (Also see scatter plots of shear vs stratification in 14 above.)

  17. Complex demodulation and a TIW composite
    1. u,v,T Periods: From 30-day guess   25-day guess
    2. u,v,T Phase time series: From 30-day guess   25-day guess   Winds
    3. u,v,T Reconstructions: Velocity components   Winds
    4. TMI SST time series and bandpass (Fusion TMI product):
      1. Along 2°N: SST(x,t)   Bandpassed   Compare APDRC
      2. At 2°N,140°W: Obs and bandpass/trend   Obs and bandpass+trend
      3. Mean amp/phase of 30-day signal). Along 140°W: Amp   Phase   Along 2°N: Amp   Phase
      4. Zonal section (x,t) along 2°N: Amp   Phase
    5. Buoy SST: Obs and bandpass   Bandpass+trend   Bandpass and C-demod amplitude
    6. Winds/currents overlays and comparisons in various combinations:
      1. Zonal winds/current (obs and bandpass): current   wind   overlay wind/current bandpass
      2. Meridional winds/current (obs and bandpass): current   wind   overlay wind/current bandpass
      3. Overlay zonal and meridional amplitude/bandpass: current   wind
      4. Overlay SST and current amplitude/bandpass (Fusion TMI product):
        1. u/SST: C-demod amplitude   bandpass
        2. v/SST: C-demod amplitude   bandpass
      5. Shear and geostrophic combos (Fusion): Amplitudes   Overlaid time series
    7. Documenting APDRC TMI vs buoy SST (and some comparisons to Fusion TMI):
      1. Time series: Whole record    Over a short interval: Fusion vs APDRC   Kelly/Dickinson correction   Example of K/D method
      2. Blanks in APDRC record
      3. Differences between APDRC and original (Fusion) TMI:
        1. (y,t) timeseries at 140°W: Fusion   APDRC   Difference
        2. Time series at 2°N,140°W: Data and difference   Lag correlation
        3. Along 2°N (x,t): Fusion   APDRC
      4. Comparisons between buoy and TMI (APDRC) SST:
        1. Time series overlay
        2. Complex demodulation:
          1. Time series and cdmod reconstruction: Buoy   APDRC
          2. Cdmod overlays: Amplitude   Phase   Period   Reconstruction   
    8. First look at a composite (30 days)
      1. (Initial) Checks (overlay bandpass and composite over Nov 04-Jan 05):
        u[k=1]=wind  u[k=2]=ug  u[k=3]=5m  v[k=1]=wind  v[k=2]=vg  v[k=3]=5m  Buoy SST  TMI SST  TMI SST (unshifted)
      2. Composite over Nov-Feb:
        1. C-demod quantities:
          Amplitude   Phase   Period   (All periods overlaid)   Reconstructions
        2. Composite over reconstruction and data:
          1. T,u,v   vectors   Winds and Grad(SST) (1/4°)   Grad(SST) (2° linefit)   Windspeed and QE
          2. Phase agreement between winds and Grad(SST)? (Not! Wind signal is small. Grad(SST) phase varies so average phase is meaningless) (Redo with 2° fitting)
        3. Composite combinations (T,wind,shear,ug,ua):
            Anomalies   (Anomalies over color T)   Include mean vectors
          1. Lineplots:   5m   10m
        4. (OLD, IGNORE: (1/4° fitting) Composite combination: All   Shear rel 20m   u and u-ug)
        5. Phase advancement and cosine angle:   Buoy SST   APDRC SST gradient (2°)   (u,v)
        6. Test using the cdmod phase to "unstretch" the bandpass
        7. Composite stratification:   
          1. T and T-T(25m)   Overlay vectors   Add uag vectors   Add mean shear vectors
          2. Bandpass time series   T-T(1m)
          3. Corresponding velocity and shear:   u   v
        8. Qe, dT/dt and windspeed composites
    9. Some comparisons between d(SST)/dt and Grad(SST):   d(SST)/dt magnitude   Grad(SST) components
    10. Tauy and dvdt:   Bandpass   Composite
    11. Binned composites:
      1. T and u binned on SST
        1. 3-panel timeseries: Obs, Cdmod, Composites (both kinds)
        2. Validations (Obs, Cdmod, Composite): T,u,v   u_g,v_g
        3. (z,t) sections: Compare old vs new composite u,v,T   Show u,u_g,u_ag shear   Add mean velocity
      2. Ertel PV
        1. Time series: Total Q   3 components of Q
        2. Validate Ertel Q terms (obs, cdmod, composite) (1-D)
        3. Original composite on 3 depths (not useful?): Obs, cdmod, composite   30-day composites overlaid
          Mean profiles: Full record   Pre-7 Oct
          (Note in the above means that the 22.5m value only includes pre-7 Oct in both cases).

  18. Examples from obs, cdmod and composite:
    1. Observed shear and stratification during a TIW transition
    2. Obs, bandpass and composite T,u,v:   Nov   Dec   Jan   Feb   

  19. v on density:   Total v    (This is wrong)

  20. Mean u and v(2°N,140°W) from Buoy, MOM, POP, ADCP
    TAO u,v timeseries at 0°,140°35m:   2002-2006   1990-2006

  21. vg timeseries from other sources:
    1. vg from TAO DH at 125°W to 155°W (missing most of our period)
    2. vg from BMRC:
      1. Time mean along 2°N
      2. vg(z,t) 150°W-130°W zonal average: May 2004 to Feb 2005   1995-2007
      3. vg(x,t) along 2°N

Other plots of interest may be found at eqsst/tiw/tiw.html (TIW work with MOM4).

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NOAA logo Dr. William S. Kessler
7600 Sand Point Way NE
Seattle WA 98115 USA
Tel:   206-526-6221
Fax:  206-526-6744
E-mail:  william.s.kessler@noaa.gov
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