Optical tools for ocean monitoring and research

Abstract

Abstract. Requirements for understanding the relationships between ocean color and suspended and dissolved materials within the water column, and a rapidly emerging photonics and materials technology base for performing optical based analytical techniques have generated a diverse offering of commercial sensors and research prototypes that perform optical measurements in water. Through inversion, these tools are now being used to determine a diverse set of related biogeochemical and physical parameters. Techniques engaged include measurement of the solar radiance distribution, absorption, scattering, stimulated fluorescence, flow cytometry, and various spectroscopy methods. Selective membranes and other techniques for material isolation further enhance specificity, leading to sensors for measurement of dissolved oxygen, methane, carbon dioxide, common nutrients and a variety of other parameters. Scientists are using these measurements to infer information related to an increasing set of parameters and wide range of applications over relevant scales in space and time.

Mineral–microbe interactions in deep-sea hydrothermal systems: a challenge for Raman spectroscopy

“…Raman spectroscopy is well suited to making measurements in the ocean because water is a relatively weak Raman scatterer (Williams & Collette 2001;Moore et al 2009). Consequently, oceanographic applications of Raman spectroscopy are decades old.…”

Physical, Bio-Optical State and Correlations in North–Western European Shelf Seas

“…It is presumed that perceived color of seawater in the NWES is strongly driven by CDOM and SPM although chl-a plays a seasonal and local role for example in the Central North Sea [32][33][34][35]. In situ station (blue dots) sampling was done in the German Bight (1)(2)(3)(4)(5)(6)(7)(8), North Sea (9-26), Inner Seas (27)(28)(29)(30)(31)(32)(33)(34), Irish Sea (35)(36)(37)(38)(39)(40)(41)(42)(43), and Celtic Sea (44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60). Region naming is based on maps from The Germany Federal Maritime and Hydrographic Agency [34] and International Hydrographic Organization [35].…”

“…The main challenges are; (i) focusing the camera to target water body; (ii) eliminating over-exposure effects from surface reflected glint in case it is set up on big ship above-water; (iii) calibrating the image to local region natural colors; and (iv) matching images to radiometric quantities for validation tasks [28]. Available hyperspectral radiometers offer stable and durable all weather optical sensors capable of collecting radiometric quantities used to derive ocean color products, e.g., the Forel-Ule Index, reflectance, and infer CPAs [16,29].…”

Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society

“…Up to date only few autonomous underwater in situ sensors are available [7] [8]. Within a collaboration of the IFM-GEOMAR and a manufacturer for underwater gas sensors (CONTROS Systems & Solutions GmbH, Kiel, Germany) a commercial pCO 2 sensor (HydroC™/CO2) is developed further.…”