Recovery of temperature records from slow-growing corals by fine scale sampling of skeletons

Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 34 (2007): L17706, doi:10.1029/2007GL030967.We used laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) to analyze Sr/Ca ratios in 5 colonies of the Atlantic corals, Diploria labyrinthiformis and Montastrea franski, each growing less than 5 mm yr−1. By targeting the centers of septa we avoided thickening deposits to achieve an analytical sampling resolution of 5-10 days. The sensitivity of Sr/Ca to temperature (−0.096 mmol/mol/°C) is ∼3 times higher than previously reported for these species and equivalent to that exhibited by fast-growing Porites corals from the Indo-Pacific. The Sr/Ca-sea surface temperature (SST) calibrations derived from these corals were not statistically different and were independent of colony growth rate over the period studied. Data from 4 D. labyrinthiformis colonies were pooled to produce a single Sr/Ca-SST calibration with a calculated standard error on the predicted ocean temperature of ±0.51°C. Applying our calibration to Sr/Ca analyses of D. labyrinthiformis skeleton deposited in the late 18th century indicated that average annual sea surface temperatures around Bermuda were ∼1°C cooler than today.This study was supported by a WHOI Ocean Life Institute fellowship to ALC, by OLI grant 25051316 to ALC and SRT, by NSF OCE-0402728 and NSF OCE- 0215905

Record of Little Ice Age sea surface temperatures at Bermuda using a growth-dependent calibration of coral Sr/Ca

Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA4016, doi:10.1029/2005PA001140.Strontium to calcium ratios (Sr/Ca) are reported for a massive brain coral Diploria labyrinthiformis collected from the south shore of Bermuda and are strongly correlated with both sea surface temperature (SST) and mean annual skeletal growth rate. High Sr/Ca ratios correspond with cold SSTs and slow skeletal growth rate and vice versa. We provide a quantitative calibration of Sr/Ca to extension rate and SST along the axis of maximum growth and derive a growth-dependent Sr/Ca–SST calibration equation to reconstruct western subtropical North Atlantic SSTs for the past 223 years. When the influence of growth rate is excluded from the calibration, Sr/Ca ratios yield SSTs that are too cold during cool anomalies and too warm during warm anomalies. Toward the end of the Little Ice Age (∼1850), SST changes derived using a calibration that is not growth-dependent are exaggerated by a factor of 2 relative to those from the growth-corrected model that yields SSTs ∼1.5°C cooler than today. Our results indicate that incorporation of growth rate effects into coral Sr/Ca calibrations may improve the accuracy of SSTs derived from living and fossil corals.A Stanley Watson Foundation Fellowship (N.F.G.), and grants from NSF (OCE-0402728) and WHOI (K.A.H., A.L.C., and M.S.M.) supported this work

Two centuries of limited variability in subtropical North Atlantic thermocline ventilation

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 3 (2012): 803, doi:10.1038/ncomms1811.Ventilation and mixing of oceanic gyres is important to ocean-atmosphere heat and gas transfer, and to mid-latitude nutrient supply. The rates of mode water formation are believed to impact climate and carbon exchange between the surface and mid-depth water over decadal periods. Here, a record of 14C/12C (1780–1940), which is a proxy for vertical ocean mixing, from an annually banded coral from Bermuda, shows limited inter-annual variability and a substantial Suess Effect (the decrease in 14C/12C since 1900). The Sargasso Sea mixing rates between the surface and thermocline varied minimally over the past two centuries, despite changes to mean-hemispheric climate, including the Little Ice Age and variability in the North Atlantic Oscillation. This result indicates that regional formation rates of sub-tropical mode water are stable over decades, and that anthropogenic carbon absorbed by the ocean does not return to the surface at a variable rate.Funding provided by NSF’s Chemical Oceanography Program OCE - 0526463 and 0961980 and the Stephen Hui Trust Fund

Environmental assessment of metal exposure to corals living in Castle Harbour, Bermuda

This paper is not subject to U.S. copyright. The definitive version was published in Marine Chemistry 154 (2013): 55–66, doi:10.1016/j.marchem.2013.05.002.Environmental contamination in Castle Harbour, Bermuda, has been linked to the dissolution and leaching of contaminants from the adjacent marine landfill. This study expands the evidence for environmental impact of leachate from the landfill by quantitatively demonstrating elevated metal uptake over the last 30 years in corals growing in Castle Harbour. Coral Pb/Ca, Zn/Ca and Mn/Ca ratios and total Hg concentrations are elevated relative to an adjacent control site in John Smith's Bay. The temporal variability in the Castle Harbour coral records suggests that while the landfill has increased in size over the last 35 years, the dominant input of metals is through periodic leaching of contaminants from the municipal landfill and surrounding sediment. Elevated contaminants in the surrounding sediment suggest that resuspension is an important transport medium for transferring heavy metals to corals. Increased winds, particularly during the 1990s, were accompanied by higher coral metal composition at Castle Harbour. Coupled with wind-induced resuspension, interannual changes in sea level within the Harbour can lead to increased bioavailability of sediment-bound metals and subsequent coral metal assimilation. At John Smith's Bay, large scale convective mixing may be driving interannual metal variability in the coral record rather than impacts from land-based activities. Results from this study provide important insights into the coupling of natural variability and anthropogenic input of contaminants to the nearshore environment.This work was supported by a grant from a postdoctoral scholarship to N.G. Prouty from the Woods Hole Oceanographic Institution and grants from the NSF (OCE-0402728; K. Hughen) and the Cove Point Foundation (C. Lamborg)

Ocean circulation and biogeochemistry moderate interannual and decadal surface water pH changes in the Sargasso Sea

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geophysical Research Letters 42 (2015): 4931–4939, doi:10.1002/2015GL064431.The oceans absorb anthropogenic CO2 from the atmosphere, lowering surface ocean pH, a concern for calcifying marine organisms. The impact of ocean acidification is challenging to predict as each species appears to respond differently and because our knowledge of natural changes to ocean pH is limited in both time and space. Here we reconstruct 222 years of biennial seawater pH variability in the Sargasso Sea from a brain coral, Diploria labyrinthiformis. Using hydrographic data from the Bermuda Atlantic Time-series Study and the coral-derived pH record, we are able to differentiate pH changes due to surface temperature versus those from ocean circulation and biogeochemical changes. We find that ocean pH does not simply reflect atmospheric CO2 trends but rather that circulation/biogeochemical changes account for >90% of pH variability in the Sargasso Sea and more variability in the last century than would be predicted from anthropogenic uptake of CO2 alone.Funding to N.F.G. was provided by the University of Hong Kong and the National Research Foundation Singapore under its Singapore NRF Fellowship scheme (National Research Fellow Award NRF-RF2012-03), as administered by the Earth Observatory of Singapore and the Singapore Ministry of Education under the Research Centres of Excellence initiative. S.C.D. and K.A.H. acknowledge support from the National Science Foundation and Woods Hole Oceanographic Institution

Variation in intravenous iron use internationally and over time: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

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East Asian Monsoon variability since the sixteenth century

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters, 46(9), (2019):4790-4798, doi:10.1029/2019GL081939.The East Asian Monsoon (EAM) impacts storms, freshwater availability, wind energy production, coal consumption, and subsequent air quality for billions of people across Asia. Despite its importance, the EAM's long‐term behavior is poorly understood. Here we present an annually resolved record of EAM variance from 1584 to 1950 based on radiocarbon content in a coral from the coast of Vietnam. The coral record reveals previously undocumented centennial scale changes in EAM variance during both the summer and winter seasons, with an overall decline from 1600 to the present. Such long‐term variations in monsoon variance appear to reflect independent seasonal mechanisms that are a combination of changes in continental temperature, the strength of the Siberian High, and El Niño–Southern Oscillation behavior. We conclude that the EAM is an important conduit for propagating climate signals from the tropics to higher latitudes.Thanks go to G. Williams, W. Tak‐Cheung, and J. Ossolinski. Thanks also go to V. Lee, S. H. Ng for coral sampling, and B. Buckley for conversations. This research was supported by the National Research Foundation Singapore NRF Fellowship scheme awarded to N. Goodkin (National Research Fellowship award NRFF‐2012‐03) and administered by the Earth Observatory of Singapore and the Singapore Ministry of Education under the Research Centers of Excellence initiative. The research was also supported by the Singapore Ministry of Education Academic Research Fund Tier 2 (award MOE2016‐T2‐1‐016). Data are available in Table S1 and the NOAA paleoclimate database

Brachioradial pruritus in a patient with cervical disc herniation and Parsonage-Turner syndrome

Brachioradial pruritus is a chronic sensory neuropathy of unknown etiology which affects the skin of the shoulders, arms and forearms on the insertion of the brachioradialis muscle. We describe the case of a 60-year old woman recently diagnosed with multiple myeloma who refers paresis, severe pruritus and itching lesions on the right arm with 6 months of evolution. Investigation led to a diagnosis of Brachioradial pruritus consequent to the presence of cervical disc herniation and Parsonage-Turner syndrome. The patient started gabapentin 900 mg/day with good control of itching. Corticosteroids and antihistamines are often ineffective in the treatment of BP. Gabapentin has been used with encouraging results. All patients with Brachioradial pruritus should be evaluated for cervical spine injuries

Diploastrea heliopora Sr/Ca and δ18O records from northeast Luzon, Philippines : an assessment of interspecies coral proxy calibrations and climate controls of sea surface temperature and salinity

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Paleoceanography 32 (2017): 424–438, doi:10.1002/2017PA003098.The Indo-Pacific coral Diploastrea heliopora reveals regional multidecadal- to centennial- scale climate variability using coral carbonate δ18O (δ18Oc) as a combined proxy for sea surface temperature (SST) and sea surface salinity (SSS). However, to assess the coral's full potential in resolving climatic events, an independent SST proxy would be more advantageous. We examined both Sr/Ca and δ18O of Diploastrea against an adjacent Porites lobata core collected from northeast Luzon, Philippines. Winter Sr/Ca data from Diploastrea show a significant correlation to SST (r = −0.41, p < 0.05, (root-mean-square of the residual) RMSR = 0.81°C) and provide a proxy with similar sensitivity as Porites (r = −0.57, p < 0.05, RMSR = 0.62°C). An interspecies SST record is shown to be robust and used for a reconstruction of the Pacific Decadal Oscillation during boreal winter (r = −0.70, p = 0.02). While we were unable to generate a robust Diploastrea δ18O-SSS calibration at interannual timescale, the freshening trend toward the present, commonly observed in the region, is qualitatively captured in Diploastrea δ18O. Comparison with Porites δ18O and instrumental SSS records shows that the magnitude of freshening is consistent between coral species. Wet and dry season Porites δ18O provide support for the relative influence of El Niño–Southern Oscillation events and local precipitation to SSS variability at our site. The multiproxy, multispecies approach of this study further strengthens the evidence for Diploastrea as an alternate climate archive in the Indo-Pacific region and seals its potential in helping resolve less understood global-scale climate phenomena.National Research Foundation Singapore (NRF) Grant Number: NRF-RF2012-0

2008: Sea surface temperature and salinity variability at Bermuda during the end of the Little Ice Age

[1] We use geochemical and isotope measurements on a 225-year old brain coral (Diploria labyrinthiformis) from the south shore of Bermuda (64°W, 32°N) to construct a record of decadal-to-centennial-scale climate variability. The coral was collected alive, and annual density bands visible in X radiographs delineate cold and warm seasons allowing for precise dating. Coral skeletons incorporate strontium (Sr) and calcium (Ca) in relative proportions inversely to the sea surface temperature (SST) in which the skeleton is secreted. Previous studies on this and other coral colonies from this region document the ability to reconstruct mean annual and wintertime SST using Sr/Ca measurements 18 O of seawater (dO w ), where dO w is proportional to sea surface salinity (SSS). We show in this study that mean annual and wintertime d 18 O of the carbonate (dO c ) are correlated to both SST and SSS, but a robust, quantitative measure of SSS is not found with present calibration data. In combination, however, the Sr/Ca and dO c qualitatively reconstruct lower salinities at the end of the Little Ice Age relative to modern day. Temperature changes agree with other records from the Bermuda region. Radiative and atmospheric forcing may explain some of the SST variability, but the scales of implied changes in SST and SSS indicate large-scale ocean circulation impacts as well