8/14/2019 Helen Final Presentation

1/23

Application of satellite derivedApplication of satellite derivedretrievals of ocean colour to theretrievals of ocean colour to the

MODIS ASTER Airborne Simulator

Helen Thomas

Student Airborne Research Program, 2009

A study over Monterey Bay,A study over Monterey Bay,

8/14/2019 Helen Final Presentation

2/23

OverviewWhy monitoring ocean colour properties (in particular,algal blooms) is important

Methods used to monitor blooms

Why Remote sensing methods are important!

Algorithms to retrieve Chlorophyll

Results

Conclusions - algorithm functionality and usefulness ofmethods

8/14/2019 Helen Final Presentation

3/23

Why study algal blooms?

Red tide bloom ofNoctiluca scintillans in NewZealand

Source:http://serc.carleton.edu/images/microbelife/t

Phytoplankton:

Base of the oceanic food chain

Are major producers of oxygen

Can affect the atmosphere by

production of DMS

Harmful Algal Blooms -

production of toxins and oxygen

depletion

8/14/2019 Helen Final Presentation

4/23

Methods

8/14/2019 Helen Final Presentation

5/23

ObjectivesMASTER = MODIS/ASTERSimulator

Comparisons Are

Important!

1. Compare MASTER andMODIS Satellite data within situ data

2. Apply satellite derivedChlorophyll a algorithms toMASTER

8/14/2019 Helen Final Presentation

6/23

Theoretical BasisFluorescence line height

Letelier and Abbott (1996)

8/14/2019 Helen Final Presentation

7/23

Theoretical BasisFluorescence line height

Letelier and Abbott (1996)

8/14/2019 Helen Final Presentation

8/23

Theoretical BasisFluorescence line height

Letelier and Abbott (1996)

8/14/2019 Helen Final Presentation

9/23

Theoretical BasisFluorescence line height

Fails under LowChlorophyll

conditions.

C

A

F

FLH = Lc-(Lf+((La-

Letelier and Abbott (1996)

But might work

in highchlorophyll

5 6 7

8/14/2019 Helen Final Presentation

10/23

8/14/2019 Helen Final Presentation

11/23

Results

BoatChlorophyll

MASTER FLH MASTER FLH

1. Fluorescence Line Height

FLH = Lc-(Lf+((La-Lf)*y/(x+y)))

8/14/2019 Helen Final Presentation

12/23

Results2. SeaWIFS OC2v4

R=log10(R490/R555) or log10(R490/R565)

Chl_oc2 = 10^(a0 + a1*R+a2*R^2+a3*R^3) +

BoatChlorophyll

MASTERChloro.

MASTERChloro.

8/14/2019 Helen Final Presentation

13/23

Results3. SeaWIFS OC4

R=log10(R443/R551) or log10(R488/R551)

Chl_oc4 =10^(a0 + a1*R +

BoatChlorophyll

MASTERChloro.

MASTERChloro.

8/14/2019 Helen Final Presentation

14/23

Results4. MODIS Chl_a

R=R443/R555 or R490/R555

Chl_a = 1o^(a0 +a1*R+a2*R^2+a3*R^3 +

BoatChlorophyll

MASTER

Chloro.

MASTERChloro.

8/14/2019 Helen Final Presentation

15/23

Results5. Polder Chl_a

R=log10(R490/R555)

Polder_chl = 10^(a0+a1*R+a2*R^2+a3*R^3)

BoatChlorophyll

MASTERChloro.

MASTERChloro.

8/14/2019 Helen Final Presentation

16/23

ResultsMODIS Time Series for July 2009

8/14/2019 Helen Final Presentation

17/23

ResultsMODIS Chl -a MODIS FLH

8/14/2019 Helen Final Presentation

18/23

Results BoatChlorophyll

MODIS Chl -a

8/14/2019 Helen Final Presentation

19/23

Results BoatChlorophyll

MODIS FLH

8/14/2019 Helen Final Presentation

20/23

IssuesTime lag

Spatial Scales

Interferences

Algorithms

Band Locations

8/14/2019 Helen Final Presentation

21/23

ConclusionsMASTER Bands are poorly positioned to retrieveFLH and Chlorophyll-a (in this case)

MODIS Chlorophyll-a retrieval reveals little in thiscase

MODIS FLH corresponds well to boat chlorophyllestimates

8/14/2019 Helen Final Presentation

22/23

8/14/2019 Helen Final Presentation

23/23

Acknowledgements