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PIC-Kd490 correlation

Posted: Tue Oct 03, 2023 12:38 pm America/New_York
by cassandra21
Hii :)

I am analysing MODIS-Aqua derived OC and SST parameters for the Cape Verde region. I applied statistical analyses to see the correlation between some of these parameters and I realized that if I use Kd490 as independent variable and PIC as dependent variable (or vice versa), there is no significant correlation among the two variables. This is strange to me because if there was a major coccolithophores bloom in some regions, I would expect the Kd value to lower accordingly. I have a high correlation between Chl a and Kd and this is expected. But, PIC has no relation with Kd490 at all? Why?

Thank you

Re: PIC-Kd490 correlation

Posted: Thu Oct 05, 2023 11:24 am America/New_York
by OB General Science - guoqingw
Hey,

If you came across data related questions or issues to report, our experts will be able to help; but for data analysis related scientific questions for a particular region, you got to figure it out by yourself.

Re: PIC-Kd490 correlation

Posted: Fri Oct 06, 2023 3:15 pm America/New_York
by OB.DAAC - SeanBailey
There may be several reasons for a lack of correlation. The empirical algorithm for Kd490 was not developed with data that includes high concentrations of PIC (i.e. coccolithophore blooms). The conditions present during an intense coccolithophore bloom likely violate the assumptions used in the development of the Kd490 algorithm. If you are doing your analysis on Level 3 data, intense coccolithophore blooms are excluded from the binning of the Kd490 product (well, alot of reflectance based products for the same reasons).

Hope this helps,
Sean