Software Open Access
The Tropical Pacific Chlorophyll Algorithm (TPCA): source code and matchup data is a supplement to Pittman et al., 2019 (2019JC015498).
The matchup dataset is coincident in situ and satellite chlorophyll observations for the tropical Pacific (10°N to 10°S and 150°E to 90°W). The matchups are defined as any coincident matchup within ±2 days and ±1 pixel (~15km). Matchup sets are provided for the satellite sensors SeaWiFS, MODIS-Aqua and MERIS.
The source code provided includes algorithms for producing the TPCA algorithm from Level 3 Mapped > Daily > 9km RRs data obtained from https://oceandata.sci.gsfc.nasa.gov/. Example scripts are provided to produce the TPCA from:
1) directly downloading data from the oceandata portal
2) from the matchup database. A number of statistical methods are provided to assess performance.
Matchup data was obtained from several sources:
1) Tropical Atmosphere Ocean (TAO) mooring maintenance cruises. This is the same dataset used by Strutton et al. (2008), provided by Francisco Chavez, Monterey Bay Aquarium Research Institute.
2) Valente et al. (2016; https://doi.org/10.1594/PANGAEA.854832)
3) Word Ocean Database 2018 (WOD; Boyer et al., 2018; https://www.nodc.noaa.gov/OC5/WOD/pr_wod.html)
Satellite to in situ matchup files as used in Pittman et al., 2019  have been openly provided for as per the Journal of Geophysical Research: Oceans guidelines.
Three files are provided. Each file is a *.csv matchup database for one of the three sensors analysed; SeaWiFS, MODIS-Aqua and MERIS.
Chlor_a and relevant Rrs data for the three sensors was downloaded from the NASA ocean color portal: https://oceandata.sci.gsfc.nasa.gov/
Monthly MEI (Multivariate ENSO Index) has matched from: https://www.esrl.noaa.gov/psd/enso/mei.old/
More details about the matchup process and sensor details / sources. R,eprocessing versions are 2018.0 for SeaWiFS and MODIS-Aqua, and 2012.1 for MERIS.
In situ fluorometric data has been compiled from three unique sources [4,5,6]
Each sensor has a different number of matchups due to time period in orbit, different orbits, cloud cover and quality control.
These matchup files are those used in ; 2 day radius and 1 pixel. This results in a total of 5 days (day, day, observation, day, day) and a grid of 9 pixels, with the observation located in the centre pixel. The matchups provided are the mean of these 45 pixels. For example in space:
Sat Sat Sat
Sat Ob Sat
Sat Sat Sat
The *.csv files contain 28 fields including:
A description of the matchup databse is available from the github repository: https://github.com/nicpittman/TPCA_source_and_matchups , release v1.0.
Pittman, N. A., Strutton, P.G., Johnson, R., Matear R., Chavez, F.P. (2019). An assessment and improvement of tropical Pacific Ocean Color algorithms. Submitted to Journal of Geophysical Research: Oceans
Hu, C., Lee, Z., and Franz, B. (2012). Chlorophyll a algorithms for oligotrophic oceans: A novel approach based on three-band reflectance difference. Journal of Geophysical Research: Oceans 117.
O'Reilly, J.E., Maritorena, S., Mitchell, B.G., Siegel, D.A., Carder, K.L., Garver, S.A., Kahru, M., and McClain, C. (1998). Ocean color chlorophyll algorithms for SeaWiFS. Journal of Geophysical Research: Oceans 103, 24937–24953.
Boyer, T.P., Baranova, O.K., Coleman, C., Garcia, H.E., Grodsky, A., Locarnini, R.A., Mishonov, A.V., Paver, C.R., Reagan, J.R., Seidov, D., et al. World Ocean Database 2018. A. V. Mishonov, Technical Editor, NOAA Atlas NESDIS 87.
Strutton, P.G., Evans, W., and Chavez, F.P. (2008). Equatorial Pacific chemical and biological variability, 1997–2003. Global Biogeochemical Cycles 22.
Valente, A., Sathyendranath, S., Brotas, V., Groom, S., Grant, M., Taberner, M., Antoine, D., Arnone, R., Balch, W.M., Barker, K., et al. (2016). A compilation of global bio-optical in situ data for ocean-colour satellite applications. Earth System Science Data 18.