Ice core evidence for a recent increase in snow accumulation in coastal Dronning Maud Land, East Antarctica

Abstract. Ice cores provide temporal records of snow accumulation, a crucial component of Antarctic mass balance. Coastal areas are particularly under-represented in such records, despite their relatively high and sensitive accumulation rates. Here we present records from a 120 m ice core drilled on Derwael Ice Rise, coastal Dronning Maud Land (DML), East Antarctica in 2012. We date the ice core bottom back to 1745 ± 2 AD. δ18O and δD stratigraphy is supplemented by discontinuous major ion profiles, and verified independently by electrical conductivity measurements (ECM) to detect volcanic horizons. The resulting annual layer history is combined with the core density profile to calculate accumulation history, corrected for the influence of ice deformation. The mean long-term accumulation is 0.425 ± 0.035 m water equivalent (w.e.) a−1 (average corrected value). Reconstructed annual accumulation rates show an increase from 1955 onward to a mean value of 0.61 ± 0.02 m w.e. a−1 between 1955 and 2012. This trend is compared to other reported accumulation data in Antarctica, generally showing a high spatial variability. Output of the fully coupled Community Earth System Model demonstrates that sea ice and atmospheric patterns largely explain the accumulation variability. This is the first and longest record from a coastal ice core in East Antarctica showing a steady increase during the 20th and 21st centuries, thereby supporting modelling predictions. </jats:p

Ice core evidence for a 20th century increase in surface mass balance in coastal Dronning Maud Land, East Antarctica

Ice cores provide temporal records of surface mass balance (SMB). Coastal areas of Antarctica have relatively high and variable SMB, but are under-represented in records spanning more than 100 years. Here we present SMB reconstruction from a 120m-long ice core drilled in 2012 on the Derwael Ice Rise, coastal Dronning Maud Land, East Antarctica. Water stable isotope (δ18O and δD) stratigraphy is supplemented by discontinuous major ion profiles and continuous electrical conductivity measurements. The base of the ice core is dated to AD1759±16, providing a climate proxy for the past 1/4&250 years. The core's annual layer thickness history is combined with its gravimetric density profile to reconstruct the site's SMB history, corrected for the influence of ice deformation. The mean SMB for the core's entire history is 0.47±0.02m water equivalent (w.e.)a'1. The time series of reconstructed annual SMB shows high variability, but a general increase beginning in the 20th century. This increase is particularly marked during the last 50 years (1962&ndash;2011), which yields mean SMB of 0.61±0.01mw.e.a'1. This trend is compared with other reported SMB data in Antarctica, generally showing a high spatial variability. Output of the fully coupled Community Earth System Model (CESM) suggests that, although atmospheric circulation is the main factor influencing SMB, variability in sea surface temperatures and sea ice cover in the precipitation source region also explain part of the variability in SMB. Local snow redistribution can also influence interannual variability but is unlikely to influence long-term trends significantly. This is the first record from a coastal ice core in East Antarctica to show an increase in SMB beginning in the early 20th century and particularly marked during the last 50 years.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The quality of life of patients with genital warts: a qualitative study

<p>Abstract</p> <p>Background</p> <p>Genital warts, which are caused by infection with human papillomavirus (HPV), are one of the most common sexually transmitted diseases in Europe. Although genital warts are commonly perceived as a non-serious condition, treatment is often long, of varying effectiveness and the recurrence rate is high. Very few studies have been performed on the personal consequences of genital warts. The aim of this qualitative study, set in Denmark, was to examine the ways in which genital warts may affect patients' quality of life.</p> <p>Methods</p> <p>To obtain an in-depth understanding of patients' perceptions of genital warts, we used qualitative focus-group interviews with five men and five women aged between 18 and 30 years who had genital warts. The interview guide was based on a literature review that identified important issues and questions. The data were analysed using a medical anthropological approach.</p> <p>Results</p> <p>Patients' experiences were related to cultural conceptions of venereal diseases and the respective identities and sexuality of the sexes. The disease had negative psychological and social effects both for men and for women and it affected their sex and love lives, in particular. The psychological burden of the disease was increased by the uncertain timeline and the varying effectiveness of treatment. We identified a need for more patient information about the disease and its psycho-sexual aspects.</p> <p>Conclusions</p> <p>The men and women participating in this study considered their quality of life to be significantly lowered because of genital warts. The experiences described by the participants give insights that may be valuable in treatment and counselling.</p> <p>The quadrivalent HPV vaccine that has now been added to the childhood vaccination programme for girls in Denmark for the prevention of cervical cancer can also prevent 90% of cases of genital warts. Our results suggest that HPV vaccination could considerably reduce the largely unacknowledged psychological and social burden associated with genital warts, in men as well as women.</p

Determination of129I in Arctic snow by a novel analytical approach using IC-ICP-SFMS

The environmental radiation background has increased in the last century due to human nuclear activities and in this context I-129 may be used to evaluate the anthropogenic contribution to global nuclear contamination. We present a fast and novel method for iodine-129 measurements. Coupling ion chromatography and inductively coupled plasma sector field mass spectrometry (IC-ICP-SFMS) allows the determination of iodine-129 at picogram per gram levels. The capability of the Dionex IONPAC (R) AS16 column to retain iodine species in the absence of NaOH has been used to pre-concentrate 5 mL samples. Although I-129 suffers from isobaric spectral interference due to the presence of Xe-129, the IC-ICP-SFMS technique allows I-129 to be determined by removing all other isobaric interferents. Furthermore, the Xe-129 interference is sufficiently small and stable to be treated as a background correction. This strategy permits the evaluation of I-129 speciation at sub-picogram per gram levels with a limit of detection (LOD) of 0.7 pg g(-1). Thus the range of possible applications of this technique is expanded to low-concentration environmental samples such as polar snow. Preliminary results obtained from Greenland (NEEM) snow pit samples confirm its applicability in environmental research

RICE ice core nitrate data for the last glacial period (83-26 ka BP)

Roosevelt Island Climate Evolution (RICE) ice core non-sea salt calcium (nssCa) and nitrate (NO3) data, covering last glacial period from 83000-26000 years BP are presented here. RICE is a 764-m long ice core retrieved from Roosevelt Island, a coastal dome in the vicinity of Ross Sea, West Antarctica. Both nssCa and NO3 data are produced using Ion Chromatography (IC) and are of decadal resolution (50-yr averaged). IC measurements were made at National Ice Core facility at GNS Science, New Zealand in 2017 as two batches. The first batch consisted of 579 samples covering the time period between ~40.6-26 ka BP. The second batch had a total of 911 samples and covered ~83-40.6 ka BP. Analytical precision is better than ~5% for Ca and is better than ~10% for NO3. Accuracy is better than ~5 % for Ca and is better than ~30% and ~10% for NO3 in the first batch and second batch, respectively. A likely reason for relatively reduced quality of NO3 measurements in the first batch of samples could be due to the extremely small contamination from drill fluid. The statistical analysis performed using the data includes correlation analysis, change-point analysis etc. In change-point analysis, influence from the outliers were minimized using hampel filter available in MATLAB ( window size=7). Only changepoints with equivalent timing as that in WAIS Divide Ice Core were considered for discussion

RICE ice core calcium data for the last glacial period (83-26 ka BP)

Roosevelt Island Climate Evolution (RICE) ice core calcium (Ca) data, measured using continuous flow analysis (CFA), covering last glacial period 83000-26000 years BP is presented here. RICE is a 764-m long ice core retrieved from Roosevelt Island, a coastal dome in the vicinity of Ross Sea, West Antarctica. The measurements were made at Centre for Ice and Climate, University of Copenhagen, Denmark in 2015 and posses annual resolution. A three-point calibration was used for the measurements

Climate changes modulated the history of Arctic iodine during the Last Glacial Cycle

Iodine has a significant impact on promoting the formation of new ultrafine aerosol particles and accelerating tropospheric ozone loss, thereby affecting radiative forcing and climate. Therefore, understanding the long-term natural evolution of iodine, and its coupling with climate variability, is key to adequately assess its effect on climate on centennial to millennial timescales. Here, using two Greenland ice cores (NEEM and RECAP), we report the Arctic iodine variability during the last 127,000 years. We find the highest and lowest iodine levels recorded during interglacial and glacial periods, respectively, modulated by ocean bioproductivity and sea ice dynamics. Our sub-decadal resolution measurements reveal that high frequency iodine emission variability occurred in pace with Dansgaard/Oeschger events, highlighting the rapid Arctic ocean-ice-atmosphere iodine exchange response to abrupt climate changes. Finally, we discuss if iodine levels during past warmer-than-present climate phases can serve as analogues of future scenarios under an expected ice-free Arctic Ocean. We argue that the combination of natural biogenic ocean iodine release (boosted by ongoing Arctic warming and sea ice retreat) and anthropogenic ozone-induced iodine emissions may lead to a near future scenario with the highest iodine levels of the last 127,000 years