Description: These data include salinity and oxygen isotope measurements of water samples collected from coastal sites along the Gulf of Maine between 2003 and 2015. In particular, a suite of samples were collected along the coast of Maine, east of Penobscot Bay, on a monthly basis between April 2014 and March 2015. These data also include several freshwater samples collected from the Kennebec and Penobscot Rivers on a semi-monthly basis in 2014 and 2015. For the water samples with sample IDs starting with DSW, JSW, NSW, or OSW: The water samples were collected by hand from shore or boat using French square glass bottles with phenolic polycone lined caps. Salinity was measured using a Oakton SALT 6+ handheld salinity meter. Oxygen isotopes were measured using a Picarro L2130-i Isotopic Liquid Water Analyzer with an attached autosampler. Water samples with sample IDs starting with ASW were collected from shore. Samples with sample IDs starting with DMC 2010 were collected at the flowing seawater laboratory at the Darling Marine Center. Samples with sample IDs starting with Summer 2011 were collected from a boat. For these last 3 sample types (ASW, DMC 2010, Summer 2011): Salinity was measured with YSI Professional Plus salinity meter and oxygen isotopes were measured using a Picarro L1102-i Isotopic Liquid Water Analyzer with an attached autosampler. Data from Owen et al., 2008 and Wanamaker et al. (2006, 2007) was collected from the flowing seawater laboratory at the Darling marine center. Salinity was measured using a YSI model 85 oxygen, conductivity, salinity, and temperature system and oxygen isotopes were measured using a dual-inlet VG/Micromass SIRA (CO2–H2O equilibration method at 30 °C for 12 h).

Description: Stable oxygen analyses and snow accumulation rates from snow pits sampled in the McMurdo Dry Valleys have been used to reconstruct variations in summer temperature and moisture availability over the last four decades. The temperature data show a common interannual variability, with strong regional warmings occurring especially in 1984/85, 1995/96 and 1990/91 and profound coolings during 1977/78, 1983/84, 1988/89, 1993/94, and 1996/97. Annual snow accumulation shows a larger variance between sites, but the early 1970s, 1984, 1997, and to a lesser degree 1990/91 are characterized overall by wetter conditions, while the early and late 1980s show low snow accumulation values. Comparison of the reconstructed and measured summer temperatures with the Southern Oscillation Index (SOI) and the Antarctic Oscillation (AAO) yield statistically significant correlations, which improve when phase-relationships are considered. A distinct change in the phase relationship of the correlation is observed, with the SOI-AAO leading over the temperature records by one year before, and lagging by one year after 1988. These results suggest that over the last two decades summer temperatures are influenced by opposing El Niño Southern Oscillation and AAO forcings and support previous studies that identified a change in the Tropical-Antarctic teleconnection between the 1980s and 1990s.

Description: To study the effects of temperature, salinity, and life processes (growth rates, size, metabolic effects, and physiological/genetic effects) on newly precipitated bivalve carbonate, we quantified shell isotopic chemistry of adult and juvenile animals of the intertidal bivalve Mytilus edulis (Blue mussel) collected alive from western Greenland and the central Gulf of Maine and cultured them under controlled conditions. Data for juvenile and adult M. edulis bivalves cultured in this study, and previously by Wanamaker et al. (2006, doi:10.1029/2005GC001189), yielded statistically identical paleotemperature relationships. On the basis of these experiments we have developed a species-specific paleotemperature equation for the bivalve M. edulis [T °C = 16.28 (±0.10) - 4.57 (±0.15) {d18Oc VPBD - d18Ow VSMOW} + 0.06 (±0.06) {d18Oc VPBD - d18Ow VSMOW}**2; r**2 = 0.99; N = 323; p 〈 0.0001]. Compared to the Kim and O'Neil (1997) inorganic calcite equation, M. edulis deposits its shell in isotope equilibrium (d18Ocalcite) with ambient water. Carbon isotopes (d13Ccalcite) from sampled shells were substantially more negative than predicted values, indicating an uptake of metabolic carbon into shell carbonate, and d13Ccalcite disequilibrium increased with increasing salinity. Sampled shells of M. edulis showed no significant trends in d18Ocalcite based on size, cultured growth rates, or geographic collection location, suggesting that vital effects do not affect d18Ocalcite in M. edulis. The broad modern and paleogeographic distribution of this bivalve, its abundance during the Holocene, and the lack of an intraspecies physiologic isotope effect demonstrated here make it an ideal nearshore paleoceanographic proxy throughout much of the North Atlantic Ocean.

Description: A high-resolution, 8000 year-long ice core record from the Mt. Logan summit plateau (5300 m asl) reveals the initiation of trans-Pacific lead (Pb) pollution by ca. 1730, and a 〉10-fold increase in Pb concentration (1981-1998 mean = 68.9 ng/l) above natural background (5.6 ng/l) attributed to rising anthropogenic Pb emissions from Asia. The largest rise in North Pacific Pb pollution from 1970-1998 (end of record) is contemporaneous with a decrease in Eurasian and North American Pb pollution as documented in ice core records from Greenland, Devon Island, and the European Alps. The distinct Pb pollution history in the North Pacific is interpreted to result from the later industrialization and less stringent abatement measures in Asia compared to North America and Eurasia. The Mt. Logan record shows evidence for both a rising Pb emissions signal from Asia and a trans-Pacific transport efficiency signal related to the strength of the Aleutian Low.