Difference between MODIS PAR and iPAR products

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svasquezp
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Difference between MODIS PAR and iPAR products

by svasquezp » Thu Oct 07, 2021 2:12 pm America/New_York

Buenas tardes,
When analyzing daily images of L3-MODIS-PAR and L2-MODIS-iPAR I have noticed that they have different daily spatial coverage. Understanding that ipar is an instant product, companion to nFLH, both daily data availability are the same. On the other hand, the PAR product, which is a daily average, presents a different daily data availability. Could you please help me understand the differences between iPAR and PAR? Also advise me on which product is most recommended to describe the radiation on the ocean surface.
Thanks
Sebastián

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OB.DAAC - amscott
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Re: Difference between MODIS PAR and iPAR products

by OB.DAAC - amscott » Thu Oct 07, 2021 6:23 pm America/New_York

Hello,

In the list of ATBDs found on the Ocean Color web, you can find links to standard products PAR and iPAR to see further explanations of each.

OB.DAAC - SeanBailey
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Re: Difference between MODIS PAR and iPAR products

by OB.DAAC - SeanBailey » Fri Oct 08, 2021 7:32 am America/New_York

If the documentation doesn't answer your questions, the short answer is:
Clouds.
The daily averaged PAR product includes contributions from cloud covered regions, while the instantaneous ipar is only computed for cloud-free pixels. Most applications would use PAR, not ipar.

Sean

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