This work describes the physical–chemical characteristics of purified cresol red for use in spectrophotometric seawater pHT measurements over the temperature and salinity ranges of 278.15 ≤ T ≤ 308.15 and 20 ≤ S ≤ 40 (at atmospheric pressure). For seawater within the range of 6.8 ≤ pHT ≤ 7.8 (at a measurement temperature of 298.15 K), we recommend the use of CR at a concentration equal to 2.5 μM. To ensure global intercomparability of measurements, investigators should use purified indicator only. Cresol red is well suited for seawater with a relatively high hydrogen ion content—e.g., waters strongly BGB324 influenced by atmospheric carbon dioxide, hydrothermal vents, or

remineralization. Waters amenable to CR analysis would therefore include high-latitude surface waters, sediment porewaters, and oxygen-minimum zones. Due to CO2-driven ocean acidification, the average pH of the global surface ocean has decreased by 0.1 since the onset of the Industrial Revolution (Orr et al., 2005). Over the 21st century, Arctic surface ocean

pH is projected to decrease by 0.45 (Steinacher et al., 2009). Ocean acidification makes cresol red an increasingly important indicator, not only for characterization of seawater pH in the world’s oceans but also for laboratory studies of the biogeochemical effects of the phenomenon. Future work will include purification and characterization EPZ5676 solubility dmso of other sulfonephthalein indicator dyes used for CO2 system analyses (e.g., thymol blue, bromocresol green, bromocresol purple,

phenol red). The procedures used in the present investigation help ensure that measurements obtained with different indicators are made on an internally consistent pH scale. This work was supported by NSF Award OCE-0727082. Support for M. Patsavas was partially provided by Inositol monophosphatase 1 the Robert M. Garrels Memorial Fellowship and the C.W. Bill Young Fellowship. Advice and insightful comments from Dr. T. Clayton are greatly appreciated. The authors gratefully acknowledge the comments and suggestions of two anonymous reviewers. “
“The authors regret that in the above article the following error occurred: Page 239 figure caption Fig. 1 should be ‘Lead emissions into the atmosphere in Italy during the years 1990–2005 (data source MSC-E, 2007)’rather than ‘Lead emissions into the atmosphere in Italy during the years 1999–2005 (data source MSC-E, 2007)’. “
“The oceans contribute significantly to the global budget of a number of atmospherically important volatile organic compounds (VOCs) (Carpenter et al., 2012, Field et al., 1998, Millet et al., 2008 and Millet et al., 2010). Marine biological, physical and photochemical processes lead to an uptake from, or an emission to, the overlying atmosphere for a suite of organic gases (e.g. DMS, isoprene, acetone, terpenes) (Lana et al., 2011, Shaw et al., 2010 and Sinha et al., 2007).