Improving Retrieval of IOPs from Ocean Color Remote Sensing Through Explicit Consideration of the Volume Scattering Function

Transcription

1 Improving Retrieval of IOPs from Ocean Color Remote Sensing Through Explicit Consideration of the Volume Scattering Function PI: Mike Twardowski Co-I: Jim Sullivan Contributors: Alberto Tonizzo, Nicole Stockley, Scott Freeman, Matt Slivkoff

2 Summary of Project Objectives VSF shape analysis IOP-AOP closure analysis with almost fully parameterized, high quality data sets Performance assessment of inversion algorithms with explicit consideration of the VSF 3-Y project initiated Sep 2015

3 VSF measurements Sequoia LISST 0.01 to 13.2 deg 32 log-space increments MASCOT 10 to 170 deg 10 degincrements

4 ~14K 1-m binned MASCOT+LISST VSFs from 10 different data sets OCVAL NY Bight 11/2007 RADYO Scripps 01/2008 OCVAL NY bight 07/2008 RADYO SB Channel 09/2008 SORTIE Ligurian Sea 10/2008 RADYO Hawaii 09/2009 ORIENT E. Sound 09/2013 NIH HAB Lake Erie 08/2014 SABOR N. Atlantic 08/2014 PACE N. Sea 04/2015 Data merged and binned to 1 m Reassessing LISST data from 2013-

5 VSF shape analysis: next steps Clean up LISST data, shift, refine protocol to concatenate with MASCOT Analytically parameterize full VSF shape Classification for water types Present at OS2016 Publish

6 Closure assessment: data sets NASA SORTIE project [Radiometry: McClean/Lewis/Trees Hyperpros] Ligurian Sea (adjacent to BUOSSOLE) Hawaii (adjacent to MOBY site) San Diego, 10 mi offshore NASA OC validation: NY Bight [Radiometry: Hooker SubOps] May 2007 Nov 2007 Jul 2008

7 Data input into RTE Hydrolight Interface is focused on ac9/s (c and a) and b b data Scattering error for absorption data c acceptance issues Choose phase function to test (e.g., FF or measured) Discretization of PF hardcoded for Petzold angles, had to be rewritten Measured phase function cannot vary with depth Standard water values in HL are not current Bottom line: You cannot feed HL fully spectrally, angularly, depth resolved total VSF and total absorption Kattawar Monte Carlo code Zege RayXP code Others?

8 absorption spectra with different scattering corrections NY Bight 11/2007 stn 6 Surface 1-m ave FF phase function measured phase function Absorption correction matters HL FF vs measured PF matters Magnitude is not terrible Spectral shape is not terrible, too steep blue-green

9 absorption spectra with different scattering corrections NY Bight 11/2007 stn 8 Surface 1-m ave FF phase function measured phase function

10 absorption spectra with different scatt corr Hawaii 03/2007 very clear Surface 1-m ave FF phase function measured phase function

11 absorption spectra with different scatt corr San Diego 01/2008 clear Surface 1-m ave FF phase function measured phase function

12 absorption spectra with different scattering corrections Ligurian Sea 10/2008 clear water Surface 1-m ave FF phase function measured phase function

13 Data set summary: OCVAL 11/2007 Correction RMSE Pct. Diff MT % BL % MT % Data are not considered in the fitting

14 Data set summary: Hawaii 03/2007 Correction RMSE Pct. Diff MT % MT % BL % Data are not considered in the fitting

15 Data set summary: Ligurian Sea 10/2008 Correction RMSE Pct. Diff RZ % MT % MT % BL % Data are not considered in the fitting

16 Data set summary: San Diego 01/2008 Correction RMSE Pct. Diff RZ % BL % MT % MT % Data are not considered in the fitting

17 Closure assessments: next steps Continue vetting input IOP and radiometry data, input uncertainties Bootstrapping: to better understand where residual biases in the data are coming from, i.e., in summary plots where slopes deviate from 1 or regression is displaced adjusting VSF by +/-2%, 5%, and 10% adjusting apg by +/-0.002, +/-0.005, and +/ /m (cal assessment) adjusting apg by +/-2%, +/-5% (scatter correction assessment) Assess with other RTE models Parameterize overall uncertainties Publish Thank you

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19 Considerations for PACE Also have extensive multi-angle DOLP data that has been analyzed to different degrees for some pubs In terms of polarimetry angles, resolving as far into the forward as possible would be useful Generically, more information content likely in linear polarization (DOLP) information than multi-angle backscatter Thank you