Need information: Dissolved Organic Matter using the ocean colour data

[nikeshnarayan]

Need information on paper works done on estimation of Dissolved Organic Matter (DOM) using the ocean colour data. Esspeacially using the aqua modis data

[skdash]

Tassan Algorithm is generally used for estimation of Dissolved Organic Matter.
I have Hard copy. Let me search softcopy and post in few hours.

skdash

[rocksea]

Is this the paper skdash is referring to?

A procedure to determine the particulate content of shallow water from
Thematic Mapper data by S. Tassan [Download here (http://us.f2.yahoofs.com/bc/421ebba9_544a/bc/Attachments/tassan_algorithm.pdf?bffTtHCB6dUYPwnw)]

Here is a smilar work done..

An improved regional algorithm to retrieve total suspended particulate matter
using IRS-P4 OCM data by Yaswant Pradhan et al.
http://www.research.plymouth.ac.uk/geomatics/publications/pradhan-I0206.pdf
One of the authors, A. V. Thomaskutty is an alumni from Dept of Physical
Oceanography, cusat. If someone has his contact details and once he joins, he
may be able to help you more regarding this.

[nikeshnarayan]

thank you roxy and shdas
the algorithm u hav given is for suspended particulates that would be helpful foer vivek but i need something for the estimation of Dissolved Organic Matter(DOM,gelbstoff) from ocean colour data from aqua MODIS pls find some papers for that :)

[skdash]

dear narayana,

Please browse SEAWIFS and MODIS ATBDs (Algorithm based documents). these two sensor are giving derived product like CDOM, Gelbstoff etc.

regards
skdash

[rocksea]

Hi nikeshnarayanan,
Dr Harilal B Menon, Reader, Dept of Marine Science, Goa University has done similar studies. I have forwarded his message on DOM to your inbox. Please read it and contact him (userid:menoncusat (http://www.oceanographers.net/forums/member.php?u=69))

With due credits to him, I am quoting a few lines of his message. It should be useful to your study. For more details, please contact him.

"Dissolved organic matter (DOM) is one of the optically active substances (OAS). In the open ocean (case I) the concentration of DOM is meagre that chlorophyll is the only OAS. But coastal waters (caseII) are optically complex. Means you have chlorophyll and inorganic materials along with DOM in these regions. Moreover if one examine the spectral variation of one of the inherent optical proerties (IOP), absoprtion coefficent, it is found that blue light is used by all these OAS in case II waters. Hence the universally accepted algorithm of blue to green band ratio adopted as an index of chlorophyll concentration in the open ocean can't be appled here. Therefore one must understand the interaction of solar flux with DOM and try to develop an algorithm for the area of your concern. As OAS differ from one coastal region to another the algorithm is site specific and season specific. Means algorithm developed for one coastal region can't be applied to another. Diferent ways to do these are 1. Inverse Modelling and Principle component analysis (PCA)

The details could be seen in Dr H B Menon's second paper in press expected to come in feb/march.

[yaswant]

Need information on paper works done on estimation of Dissolved Organic Matter (DOM) using the ocean colour data. Esspeacially using the aqua modis dataNikesh,
Tassan's algorithm was a primitive yet useful one during the last decade. I do not know any of the contemporary ocean colour missions providing CDOM as a standard product. Nevertheless, you may wish to use MODIS Ocean products (e.g. Phycoerythrobilin abs, Phycourobilin abs and Gelbstoff absorption coefficient @ 400 nm). Since CDOM/Gelbstoff/Yello Substances are spatially limited to the coastal waters, the problem is obviously complex due to their spectral overlapping and non-linear behaviour with other optically active constituents. Apparently, you should be careful while using these products, especially for Indian coasts where we have hardly any CDOM measurements (I am still sceptical whether we have been doing any CDOM sampling in India lately or not!).

You need your own parametrisation to get CDOM in absolute concentration for your region of interest. Difficult... not impossible.
best wishes,
yaswant