Abstract:

Level 1 Moderate Resolution Imaging Spectroradiometer (MODIS) data is processed to extract the remote sensing reflectance at the wavelength of 645 nm and binned into an 8-day composite at a resolution of 500 m. The study uses a regional ocean color algorithm to compute suspended particulate matter concentration based on these 8-day composites.

Suggested Citation:

Wiggert, Jeremy (Jerry); O'Brien, Stephan. 2018. Time series of MODIS-Aqua 8-days Suspended Particles Matter (SPM) composites from 2012 to 2016 for the northern Gulf of Mexico. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N76W98FS

Purpose:

To analyze the spatiotemporal changes in suspended particulate matter in the northern Gulf of Mexico.

Data Parameters and Units:

Latitude (lat, degrees N), Longitude (lon, degrees W), Suspended particulate matter (SPM, mg/L) Filename structure example A20161772016184_MODISA_500m_8d_spm_zhoa.nc: A = Aqua, Year= 2016, first day of 8-day composite = 177 (Julian day), Year= 2016, last day of 8-day composite=184 (Julian day), satellite and sensor= MODISA, spatial resolution= 500m, binning=8-days composite, SPM algorithm

Methods:

Ocean color satellite imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite were downloaded from the NASA Goddard Space Flight Center, Distributed Active Archive Center from 2012 to 2016 (2014 Reprocessing. NASA OB.DAAC, Greenbelt, MD, USA. doi:10.5067/AQUA/MODIS/MODIS_OC.2014.0). Data was downloaded at Level-1 and processed to Level-2 using the SeaWiFS Data Analysis System (SeaDAS, version 7.3.2) and L2-gen. Daily Remote sensing reflectance at 645 nm (Rrs-645) was binned into an 8-day composite and mapped to a cylindrical projection at 1 km pixel resolution at a resolution of 500 nm. The study uses a regional ocean color algorithm to compute suspended particulate matter (SPM) concentration (Zhao et al., 2011). Zhao et al., (2011) SPM algorithm uses water reflectance (ρw) to derive SPM, however for this dataset we used Rrs-645. Please note that this may cause erroneous values, so we recommend to use the data only for qualitative analyses when validation is available. Level-2 flags (ATMFAIL, LAND, PRODWARN, HIGLINT, HILT, HISATZEN, COASTZ, STRAYLIGHT, CLDICE, COCCOLITH, TURBIDW, HISOLZEN, LOWLW, CHLFAIL, NAVWARN, ABSAER, MAXAERITER, MODGLINT, CHLWARN, ATMWARN, SEAICE, NAVFAIL, FILTER, HIPOL, PRODFAIL) were applied to discard low-quality data. Algorithm reference: Zhao, H., Q. Chen. N.D. Walker, Q. Zheng & H.L. MacIntyre. (2011). A study of sediment transport in a shallow estuary using MODIS imagery and particle tracking simulation. International Journal of Remote Sensing, 32(21): 6653-6671. doi: 10.1080/01431161.2010.512938

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