Although sulfur is an essential element for marine primary production and critical for climate processes, little is known about the oceanic pool of nonvolatile dissolved organic sulfur (DOS). We present a basin-scale distribution of solid-phase extractable DOS in the East Atlantic Ocean and the Atlantic sector of the Southern Ocean. Although molar DOS versus dissolved organic nitrogen (DON) rat...

We document an example of a forested watershed at the Coweeta Hydrologic Laboratory with an extraordinary tendency to retain dissolved organic matter (DOM) generated in large quantities within the ecosystem. Our objectives were to determine fluxes of dissolved organic C, N, and P (DOC, DON, DOP, respectively), in water draining through each stratum of the ecosystem and synthesize information on...

The chemical composition of high molecular weight dissolved organic matter (DOM) and particulate organic matter (POM) was examined along the salinity gradient of the Delaware Estuary. DOM was collected and fractionated by tangential-flow ultrafiltration into 1–30 kDa (HDOM; high molecular weight) and 30 kDa to 0.2 mm (VHDOM; very high molecular weight) and compared to particles collected in par...

Recent evidence that dissolved organic carbon (DOC) is a significant component of the organic carbon flux below the photic layer of the ocean (1), together with verification of high respiration rates in the dark ocean (2), suggests that the downward flux of DOC may play a major role in supporting respiration there. Here we show, on the basis of examination of the relation between DOC and appare...

The majority of organic carbon in the oceans is present as dissolved organic matter (DOM); therefore understanding the distribution and dynamics of DOM is central to understanding global carbon cycles. Describing the time-space variability in colored dissolved organic matter (CDOM) has been difficult, as standard spectrophotometric methods for CDOM determination are laborious and susceptible to...

Fog samples were collected in two population centers of the US Gulf Coast (Houston, Texas and Baton Rouge, Louisiana) using Caltech active strand cloud collectors. A total of 32 fogwater samples were collected in Baton Rouge (November 2004–February 2005) and Houston (February 2006). These samples were analyzed for pH, total and dissolved organic carbon, major inorganic ions, and a variety of or...

We report measurements of oceanic black carbon (BC) to determine the sources of BC to abyssal marine sediments in the northeast Pacific Ocean. We find that the average C age of BC is older (by 6200±2200 C years) than that of the concurrently deposited non-BC sedimentary organic carbon. We investigate sources of aged BC to sediments by measuring a sample of sinking particulate organic carbon (PO...

[1] Reconstructing the dissolved carbon dioxide of surface waters from the dC of organic carbon relies on accurate determination of the growth rate of phytoplankton contributing to sedimentary organic matter. We demonstrate that the Sr/Ca ratio in the coccoliths of Emiliania huxleyi is correlated with the rates of both organic carbon fixation and calcification. An investigation of biomineraliza...

Bacterial respiration (BR) of organic matter is an important flux in the carbon budgets of large rivers, yet the regulation of BR and the relationship of this respiration to various organic matter sources is poorly understood. Using detailed spatial transects, we evaluated transport and consumption of dissolved organic matter in the Hudson River estuary, and compared both with BR. Dissolved org...

We measured black carbon (BC) in ultrafiltered, high–molecular weight dissolved organic matter (UDOM) in surface waters of Delaware Bay, Chesapeake Bay, and the adjacent Atlantic Ocean (U.S.A.) to investigate the importance of riverine and estuarine dissolved organic matter (DOM) as a source of BC to the ocean. BC was 5– 72% of UDOM-C (27 6 17%), which corresponds to 8.9 6 6.5% of dissolved org...