The Voluntary Observing Ships (VOS) Scheme is an observing program for marine meteorology, continuing a record extending back centuries. VOS are an important component of the surface observing system, providing air and sea surface temperatures, humidity, pressure, wind speed and direction, cloud cover, waves, ice and weather data. Observational metadata allow biases to be diagnosed and corrected.Despite its importance, the Scheme faces challenges. Observation numbers have declined as more data from satellites and buoys becomes available. However, buoys and satellites do not replace the full multivariate VOS record, which is needed for applications including climate monitoring, air-sea interaction and satellite validation. Other issues include changes to the transmission system and the security and commercial concerns of ship operators whose ships are identified in the data stream. Current initiatives are aimed at improving data quality, real time metadata availability and archival of data for climate applications.

The GODAE-OceanView collection of papers primarily concerns the development of ocean data-assimilation models for operational oceanography. However, these models cannot function without a secure supply of in situ ocean data in near real-time. Several projects and programmes supply such data. The purpose of this paper is to review these data sources and describe the history, present status, future and robustness of these programmes. The conclusion is that though challenges continue with some components of the Global Ocean Observing System, overall the system continues to evolve and improve. The data are available in real-time to drive assimilation models, and expectations are increasing for more observational data. The prospects for the next 10 years seem to be good. All of the systems are evolving and there is little doubt that the Global Ocean Observing System will look different 10 years from now as new technologies emerge and capabilities improve.This work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 USC. 105, no copyright protection is available for such works under US Law.

The role of dissolved organic matter (DOM) as either a sink for inorganic nutrients or an additional nutrient source is an often-neglected component of nutrient budgets in aquatic environments. Here, we examined the role of DOM in reactive nitrogen (N) storage in Sierra Nevada (California, USA) lakes where atmospheric deposition of N has shifted the lakes toward seasonal phosphorus (P)-limitation. Nuclear magnetic resonance (NMR) spectroscopy and isotope analyses performed on DOM isolated from Lake Tahoe reveal the accumulation of refractory proteinaceous material with a 100-200-year residence time. In contrast, smaller lakes in the same watershed contain DOM with typical terrestrial characteristics, indicating that proteins in Lake Tahoe are autochthonously produced. These data support the role of DOM as a possible sink for reactive N in these lake ecosystems and identify a potential role for DOM in affecting the inorganic nutrient stoichiometry of these environments.

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