DOI: 10.5061/dryad.8pk0p2p14
title: Data from: The primacy of dissolved organic matter to aquatic light variability

description: This dataset contains eigenanalyses results for apparent optical property
 observations of aquatic environments. Eigenanalyses were conducted to
 assess the primary sources of variability in the aquatic light field, and
 the results are associated with the Biogeosciences publication
 Houskeeper and Hooker (2025). Methodological details, including underlying
 dataset descriptions, plus post-processing and quality control, are
 provided in the associated publication. Descriptions of the underlying
 datasets used for conducting the eigenanalyses are also summarized in the
 dataset readme.
description: # Eigenanalyses of Aquatic Optical Property Datasets This dataset contains
 the results of eigenanalyses conducted using apparent optical property
 observations of aquatic environments. The eigenanalyses were conducted to
 assess the primary sources of variability in the aquatic light field, and
 the results are associated with the *Biogeosciences* publication
 Houskeeper and Hooker (2025). Methodological details, including
 descriptions of the underlying datasets, plus post-processing and quality
 control, are provided in the associated publication. Brief descriptions
 plus additional methodological references are included below. ##
 Associated Publication **Houskeeper, H.F. and S.B. Hooker.** "The
 primacy of dissolved organic matter to aquatic light variability."
 *Biogeosciences* (2025). ## Dataset Summaries ### Fig. 1: Eigenfunctions
 The first three eigenfunctions for each of the underlying datasets, as
 well as the oligotrophic subset, are organized in sheets. Each sheet is
 associated with an underlying dataset or its oligotrophic subset
 corresponding to the sheet name. The initial column of each sheet
 represents the waveband characteristics of the underlying dataset. ###
 Fig. 2: Field and Algorithmic Observations Data products indicating Ca and
 aCDOM (440) are presented for each of the underlying datasets, as
 applicable. Each sheet is associated with an underlying dataset
 corresponding to the sheet name. Data products are denoted as algorithmic
 or field observations, depending on contemporaneous field observations
 where available. Algorithmic Ca is derived using the NASA OC4 algorithm,
 and algorithmic aCDOM (440) is derived using end-member analysis, with the
 applicable equation and coefficients specified in the associated
 publication. ### Fig. 3: Variance Explained The variance explained by the
 first 6 eigenfunctions is presented for each of the underlying datasets.
 Summaries of the underlying datasets are presented below. Additional
 information is also shown for the data products presented in: **Cael, B.
 B., Kelsey Bisson, Emmanuel Boss, and Zachary K. Erickson.** "How
 many independent quantities can be extracted from ocean color?."
 *Limnology and Oceanography Letters* 8, no. 4 (2023): 603-610. ##
 Underlying Dataset Summaries The analyses are based on underlying
 datasets, which are briefly summarized, with naming conventions indicating
 the associated publication journal and year, as follows: ### RSE2021
 Global (i.e., oceanic, coastal, and inland water) normalized water-leaving
 radiance (nLw) data products are derived from observations obtained using
 the digital C-OPS with C-PrOPS instrument suite (Houskeeper et al. 2021).
 The observations correspond to an average vertical sampling resolution
 (VSR) of 6.0 mm, indicating the depth intervals at which profile
 measurements were obtained, with a maximum VSR of 0.9 mm. Initial
 observations of the upwelling radiance are obtained at approximately 0.3 m
 depth, corresponding to the length of the downward-pointing radiance
 radiometer. Additional quality control and methodological details are
 provided in Hooker et al. (2020) and Houskeeper et al. (2021). The dataset
 includes contemporaneous observations of Ca and the absorption of colored
 dissolved organic matter at 440 nm, aCDOM(440). Spectral subsets of
 RSE2021 are named, as follows: UVN21 corresponds to the full spectral
 domain (i.e., is identical to RSE2021); VIS21 corresponds to the visible
 spectral domain (400-700 nm) data products from RSE2021; and UVN
 corresponds to the non-visible spectral domain (&lt; 400 nm or &gt; 700
 nm) data products from RSE2021. ### RSE2022 Oceanic and coastal ocean nLw
 data products are derived from spectrometer observations using
 rocket-shaped profilers and buoys (Kramer et al. 2022). The dataset is
 accessed via Kramer et al. (2021) and includes contemporaneous
 observations of Ca. ### RSE2007 Oceanic nLw data products are derived from
 observations obtained using primarily analog free-falling instrument
 suites during open-ocean field campaigns, plus some coastal zone stations
 (Morel et al. 2007). The dataset includes contemporaneous observations of
 Ca. For RSE2022 and RSE2007, which do not include contemporaneous
 observations of aCDOM(440), algorithmic estimates of aCDOM(440) are
 obtained using end-member analysis following Houskeeper et al. (2021) and
 as described in the associated manuscript. Oligotrophic subsets for each
 dataset are obtained by filtering observations associated with Chlorophyll
 a concentration (Ca) observations less than 0.5 mg m⁻³. ## Additional
 Methodological References Additional methodological details associated
 with the hardware, software, and sampling protocols for the RSE2021
 dataset are provided in the following publications: 1. **Houskeeper, H.F.,
 S.B. Hooker, and R.N. Lind.** "Expanded linear responsivity for Earth
 and planetary radiometry." *Journal of Atmospheric and Oceanic
 Technology* 41, no. 11 (2024): 1093-1105.
 [https://doi.org/10.1175/JTECH-D-23-0133.1](https://doi.org/10.1175/JTECH-D-23-0133.1) 2. **Houskeeper, Henry F., and Stanford B. Hooker.** "Extending aquatic spectral information with the first radiometric IR-B field observations." *PNAS Nexus* 2 no. 11 (2023). [https://doi.org/10.1093/pnasnexus/pgad340](https://doi.org/10.1093/pnasnexus/pgad340) 3. **Hooker, S.B., H.F. Houskeeper, R.N. Lind, and K. Suzuki.** "One- and two-band sensors and algorithms to derive aCDOM(440) from global above- and in-water optical observations." *Sensors* 21, no. 16 (2021): 5384. [https://doi.org/10.3390/s21165384](https://doi.org/10.3390/s21165384) 4. **Houskeeper, H.F., S.B. Hooker, and R.M. Kudela.** "Spectral range within global aCDOM(440) algorithms for oceanic, coastal, and inland waters with application to airborne measurements." *Remote Sensing of Environment* 253C (2021): 112155. [https://doi.org/10.1016/j.rse.2020.112155](https://doi.org/10.1016/j.rse.2020.112155) 5. **Guild, L.S., R.M. Kudela, S.B. Hooker, S.L. Palacios, and H.F. Houskeeper.** "Airborne radiometry for calibration, validation, and research in oceanic, coastal, and inland waters." *Frontiers in Environmental Science* 8, no. 585529 (2020): 209. [https://doi.org/10.3389/fenvs.2020.585529](https://doi.org/10.3389/fenvs.2020.585529) 6. **Hooker, S.B., A. Matsuoka, R.M. Kudela, Y. Yamashita, K. Suzuki, and H.F. Houskeeper.** "A global end-member approach to derive aCDOM(440) from near-surface optical measurements." *Biogeosciences* 17, no. 2 (2020): 475-497. [https://doi.org/10.5194/bg-17-475-2020](https://doi.org/10.5194/bg-17-475-2020) 7. **Hooker, S.B., H.F. Houskeeper, R.M. Kudela, K. Suzuki, and R.N. Lind.** "Verification and validation of hybridspectral radiometry obtained from an unmanned surface vessel (USV) in the open and coastal oceans." *Remote Sensing* 14, no. 5 (2022): 1084. [https://doi.org/10.3390/rs14051084](https://doi.org/10.3390/rs14051084) 8. **Houskeeper, H.F., S.B. Hooker, and Ky.C. Cavanaugh.** "Spectrally simplified approach for leveraging legacy geostationary oceanic observations." *Applied Optics* 61, no. 27 (2022): 7966-7977. [https://doi.org/10.1364/AO.465491](https://doi.org/10.1364/AO.465491) 9. **Hooker, S.B., H.F. Houskeeper, R.M. Kudela, A. Matsuoka, K. Suzuki, and T. Isada.** "Spectral modes of radiometric measurements in optically complex waters." *Continental Shelf Research* 219 (2021): 104357. [https://doi.org/10.1016/j.csr.2021.104357](https://doi.org/10.1016/j.csr.2021.104357) 10. **Hooker, Stanford B., Randall N. Lind, John H. Morrow, James W. Brown, Koji Suzuki, Henry F. Houskeeper, Toru Hirawake, and Elígio de Ráus Maúre.** *Advances in above-and in-water radiometry, volume 1: enhanced legacy and state-of-the-art instrument suites.* NASA/TP–2018-219033/VOL. 1. 2018. 11. **Hooker, Stanford B., Randall N. Lind, John H. Morrow, James W. Brown, Raphael M. Kudela, Henry F. Houskeeper, and Koji Suzuki.** *Advances in above-and in-water radiometry, volume 2: autonomous atmospheric and oceanic observing systems.* GSFC-E-DAA-TN68732. 2018. 12. **Hooker, Stanford B., Randall N. Lind, John H. Morrow, James W. Brown, Raphael M. Kudela, Henry F. Houskeeper, and Koji Suzuki.** *Advances in above-and in-water radiometry, volume 3: hybridspectral next-generation optical instruments.* NASA/TP–2018-219033/VOL. 3. 2018.