Improving sea level simulation in Mediterranean regional climate models

For now, the question about future sea level change in the Mediterranean remains a challenge. Previous climate modelling attempts to estimate future sea level change in the Mediterranean did not meet a consensus. The low resolution of CMIP-type models prevents an accurate representation of important small scales processes acting over the Mediterranean region. For this reason among others, the use of high resolution regional ocean modelling has been recommended in literature to address the question of ongoing and future Mediterranean sea level change in response to climate change or greenhouse gases emissions. Also, it has been shown that east Atlantic sea level variability is the dominant driver of the Mediterranean variability at interannual and interdecadal scales. However, up to now, long-term regional simulations of the Mediterranean Sea do not integrate the full sea level information from the Atlantic, which is a substantial shortcoming when analysing Mediterranean sea level response. In the present study we analyse different approaches followed by state-of-the-art regional climate models to simulate Mediterranean sea level variability. Additionally we present a new simulation which incorporates improved information of Atlantic sea level forcing at the lateral boundary. We evaluate the skills of the different simulations in the frame of long-term hindcast simulations spanning from 1980 to 2012 analysing sea level variability from seasonal to multidecadal scales. Results from the new simulation show a substantial improvement in the modelled Mediterranean sea level signal. This confirms that Mediterranean mean sea level is strongly influenced by the Atlantic conditions, and thus suggests that the quality of the information in the lateral boundary conditions (LBCs) is crucial for the good modelling of Mediterranean sea level. We also found that the regional differences inside the basin, that are induced by circulation changes, are model-dependent and thus not affected by the LBCs. Finally, we argue that a correct configuration of LBCs in the Atlantic should be used for future Mediterranean simulations, which cover hindcast period, but also for scenarios

Investigation of Relationships between Urinary Biomarkers of Phytoestrogens, Phthalates, and Phenols and Pubertal Stages in Girls

BackgroundHormonally active environmental agents may alter the course of pubertal development in girls, which is controlled by steroids and gonadotropins.ObjectivesWe investigated associations of concurrent exposures from three chemical classes (phenols, phthalates, and phytoestrogens) with pubertal stages in a multiethnic longitudinal study of 1,151 girls from New York City, New York, greater Cincinnati, Ohio, and northern California who were 6-8 years of age at enrollment (2004-2007).MethodsWe measured urinary exposure biomarkers at visit 1 and examined associations with breast and pubic hair development (present or absent, assessed 1 year later) using multivariate adjusted prevalence ratios (PR) and 95% confidence intervals (CIs). Modification of biomarker associations by age-specific body mass index percentile (BMI%) was investigated, because adipose tissue is a source of peripubertal hormones.ResultsBreast development was present in 30% of girls, and 22% had pubic hair. High-molecular-weight phthalate (high MWP) metabolites were weakly associated with pubic hair development [adjusted PR, 0.94 (95% CI, 0.88-1.00), fifth vs. first quintile]. Small inverse associations were seen for daidzein with breast stage and for triclosan and high MWP with pubic hair stage; a positive trend was observed for low-molecular-weight phthalate biomarkers with breast and pubic hair development. Enterolactone attenuated BMI associations with breast development. In the first enterolactone quintile, for the association of high BMI with any development, the PR was 1.34 (95% CI, 1.23-1.45 vs. low BMI). There was no BMI association in the fifth, highest quintile of enterolactone.ConclusionsWeak hormonally active xenobiotic agents investigated in this study had small associations with pubertal development, mainly among those agents detected at highest concentrations

Persistent acceleration in global sea-level rise since the 1960s

Previous studies reconstructed twentieth-century global mean sea level (GMSL) from sparse tide-gauge records to understand whether the recent high rates obtained from satellite altimetry are part of a longer-term acceleration. However, these analyses used techniques that can only accurately capture either the trend or the variability in GMSL, but not both. Here we present an improved hybrid sea-level reconstruction during 1900–2015 that combines previous techniques at time scales where they perform best. We find a persistent acceleration in GMSL since the 1960s and demonstrate that this is largely (~76%) associated with sea-level changes in the Indo-Pacific and South Atlantic. We show that the initiation of the acceleration in the 1960s is tightly linked to an intensification and a basin-scale equatorward shift of Southern Hemispheric westerlies, leading to increased ocean heat uptake, and hence greater rates of GMSL rise, through changes in the circulation of the Southern Ocean

The Endocrine Disruptor Mono-(2-Ethylhexyl) Phthalate Affects the Differentiation of Human Liposarcoma Cells (SW 872)

Esters of phthalic acid (phthalates) are largely used in industrial plastics, medical devices, and pharmaceutical formulations. They are easily released from plastics into the environment and can be found in measurable levels in human fluids. Phthalates are agonists for peroxisome proliferator-activated receptors (PPARs), through which they regulate translocator protein (TSPO; 18 kDa) transcription in a tissue-specific manner. TSPO is a drug- and cholesterol-binding protein involved in mitochondrial respiration, steroid formation, and cell proliferation. TSPO has been shown to increase during differentiation and decrease during maturation in mouse adipocytes. The purpose of this study was to establish the effect of mono-(2-ethylhexyl) phthalate (MEHP) on the differentiation of human SW 872 preadipocyte cells, and examine the role of TSPO in the process. After 4 days of treatment with 10 µM MEHP, we observed changes in the transcription of acetyl-CoA carboxylase alpha, adenosine triphosphate citrate lyase, glucose transporters 1 and 4, and the S100 calcium binding protein B, all of which are markers of preadipocyte differentiation. These observed gene expression changes coincided with a decrease in cellular proliferation without affecting cellular triglyceride content. Taken together, these data suggest that MEHP exerts a differentiating effect on human preadipocytes. Interestingly, MEHP was able to temporarily increase TSPO mRNA levels through the PPAR-α and β/δ pathways. These results suggest that TSPO can be considered an important player in the differentiation process itself, or alternatively a factor whose presence is essential for adipocyte development

Using Shelf‐Edge Transport Composition and Sensitivity Experiments to Understand Processes Driving Sea Level on the Northwest European Shelf

AbstractVariability in ocean currents, temperature and salinity drive dynamic sea level (DSL) variability on the Northwest European Shelf (NWES). It is dominated by mass variations, with steric signals relatively small. A mechanistic explanation of how ocean dynamics relates to the mass component of NWES sea level variability is required. We use regional ocean model experiments to isolate sources of variability and then investigate the effect on monthly to‐interannual DSL variability together with the simulated momentum budgets along the shelfbreak. Regional (local) wind and non‐regional (remote) forcing are important on the NWES. For the local wind forcing, the net mass flux onto the shelf, which drives a shelf‐mean mode of DSL variability, results from a combination of surface Ekman, bottom Ekman and geostrophic flows and explains 73% of the variance in transport across the shelf‐edge. The geostrophic flow is closely related to wind stress with a flow about half that of surface Ekman transport but in the opposite direction. For the remotely forced mass‐flux across the shelf‐edge, the geostrophic component explains 62% of the variance and bottom friction plays an important indirect role. The remotely forced variability, while relatively spatially uniform, is more important for explaining DSL variance over the western NWES. This mode of variability is sensitive to signals propagating northward via a thin strip of the southern boundary near the Portuguese coast, consistent with coastal trapped wave signals. It also appears to drive steric height in the Bay of Biscay, which is related to DSL on the shelf.</jats:p

Imprints of wave climate and mean sea level variations in the dynamics of a coastal spit over the last 250 years: Cap Ferret, SW France

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Perfluorooctanoate and changes in anthropometric parameters with age in young girls in the Greater Cincinnati and San Francisco Bay Area

MethodsWe conducted a study of per- and polyfluoroalkyl substance biomarkers, including PFOA, in girls from Greater Cincinnati (CIN, N = 353) and the San Francisco Bay Area (SFBA, N = 351). PFOA was measured in the baseline serum sample collected in 2004-2007 of 704 girls at age 6-8 years. Mixed effects models were used to derive the effect of PFOA on BMI, waist-to-height and waist-to-hip ratios over increasing age in this longitudinal cohort.ResultsMedian PFOA serum concentrations were 7.3 (CIN) and 5.8 (SFBA) ng/mL, above the U.S. population median for children 12-19 years in 2005-2006 (3.8&nbsp;ng/mL). Log-transformed serum PFOA had a strong inverse association with BMIz in the CIN girls (p&nbsp;=&nbsp;0.0002) and the combined two-site data (p&nbsp;=&nbsp;0.0008); the joint inverse effect of PFOA and Age*PFOA weakened at age at 10-11 years. However, in the SFBA group alone, the relationship was not significant (p&nbsp;=&nbsp;0.1641) with no evidence of changing effect with age. The effect of PFOA on waist:height ratio was similar to BMIz at both sites, but we did not find a significant effect of PFOA on waist:hip ratio in either the CIN or SFBA girls.ConclusionsPFOA is associated with decreased BMI and waist:height ratio in young girls, but the strength of the relationship decreases with age. Site heterogeneity may be due to greater early life exposure in Cincinnati.DisclaimerThe findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Use of trade names is for identification only and does not imply endorsement by the CDC, the Public Health Service, or the US Department of Health and Human Services