Earthdata Forum

Hello everyone,

I was analysing PACE Rrs data and observed a sharp drop in values between ~553 nm and 555 nm (e.g., from 0.0008 at 553 nm to 0.0004 at 555 nm). Is this expected behaviour or could it be an artifact? I am observing this same pattern in several of my analyses...

I’ve attached an example of my data (Rrs_PACE.png) to illustrate the issue.

Any guidance on whether this is typical or warrants further investigation would be greatly appreciated.

Thanks in advance for your help!
Cassandra

Hi Cassandra,

It will help if you could post the granule name as well as the location of this pixel.

Best,
Minwei

Hi Minwei,

Yes, of course.

Granule name: PACE_OCI.20240701T112757.L2.OC_AOP.V3_0.nc

Pixel location: 67.7667236328125 (lat_pixel); 10.0829572677612 (lon_pixel)

Best,
Cassandra

Hi Cassandra,

This is the spectra I got from the L2 file for the pixel you provided. I didn't see the sharp drop. Please let me know for further questions. Best,
Minwei

Hi,

Could you please explain how you did it?

I'm using a MATLAB script to extract data from the PACE files after applying some flags, and I ended up with the results I showed you. In fact, I've generated several similar graphs showing the same drop across different pixels.

Best regards,
Cassandra

I am using SeaDAS to export the spectra.

Minwei

Hi Cassandra, my guess from comparing your plot to Minwei's is that you are using the wrong wavelength dimension for the x-axis.

Thanks Andy for the note.

Please note Rrs in the wavelength range of 588-613 nm are not generated in this L2 file.

Minwei

Hi,

Thank you both for your input.

I've attached the results I'm getting from extracting Rrs data for that pixel.

If Rrs values for the wavelengths between 588–613 nm are not generated in this file, how is it possible that I'm still able to extract data for them?

Cassandra

I am not clear how your MATLAB script works but how did you get the numbers in "Rrs_band"?
Minwei