587 research outputs found
Exceptionally warm and prolonged flow of warm deep water toward the Filchner-Ronne Ice Shelf in 2017
Get PDF© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ryan, S., Hellmer, H. H., Janout, M., Darelius, E., Vignes, L., & Schroeder, M. Exceptionally warm and prolonged flow of warm deep water toward the Filchner-Ronne Ice Shelf in 2017. Geophysical Research Letters, 47(13),(2020): e2020GL088119, doi:10.1029/2020GL088119.The Filchner‐Ronne Ice Shelf, fringing the southern Weddell Sea, is Antarctica's second largest ice shelf. At present, basal melt rates are low due to active dense water formation; however, model projections suggest a drastic increase in the future due to enhanced inflow of open‐ocean warm water. Mooring observations from 2014 to 2016 along the eastern flank of the Filchner Trough (76°S) revealed a distinct seasonal cycle with inflow if Warm Deep Water during summer and autumn. Here we present extended time series showing an exceptionally warm and long inflow in 2017, with maximum temperatures exceeding 0.5°C. Warm temperatures persisted throughout winter, associated with a fresh anomaly, which lead to a change in stratification over the shelf, favoring an earlier inflow in the following summer. We suggest that the fresh anomaly developed upstream after anomalous summer sea ice melting and contributed to a shoaling of the shelf break thermocline.The authors would like to express their gratitude to the officers and crews of RV Polarstern (cruises PS92 [Grant AWI_PS82_02], PS96 [Grant AWI_PS96_01], and PS111 [Grant AWI_PS111_01]), RRS Ernest Shackleton (Cruise ES060), and RSS James Clark Ross (Cruise JR16004) for their efficient assistance. E. D. received funding from the project TOBACO (267660), POLARPROG, Norges Forskningsrd
Esophageal cancer in Central and Eastern Europe: Tobacco and alcohol
No full textEsophageal cancer mortality rates in Central and Eastern Europe have been increasing steadily and are expected to increase further in the future. To evaluate the role of risk factors for esophageal cancer in this population, a multicenter study was conducted, with investigation of tobacco and alcohol as one of the principal aims. We have included 192 squamous cell carcinoma (SCC) and 35 adenocarcinoma cases of the esophagus diagnosed at designated hospitals in 5 centers from Romania, Russia, the Czech Republic and Poland. Controls were frequency matched from patients in the same hospital as the cases (n = 1,114). Our results showed that the risk of esophageal SCC may be increased by approximately 7-fold for current smokers (OR = 7.41, 95% CI 3.98-13.79) and by 3-fold for ever alcohol drinkers (OR = 2.86, 95% CI 1.06-7.74). Dose-response relations were evident for both the frequency and duration of tobacco and of alcohol on the risk of esophageal SCC. Risk estimates for tobacco smoking were highest for lower esophageal SCCs, while risk estimates for alcohol drinking were highest for upper esophageal SCCs; though differences were not statistically significant. For adenocarcinoma of the esophagus, our results suggested a more modest increase in risk because of tobacco smoking than that for SCC of the esophagus and no association with alcohol consumption, although our sample size was small. A Synergist it interaction between tobacco and alcohol was observed for the risk of esophageal SCC, highlighting the importance of both factors for esophageal cancers in Central and Eastern Europe. © 2007 Wiley-Liss. Inc
Current and echo backscatter measurements on the Laptev Sea shelf in 2013-2014 at mooring site Kotelny-T1-13
No full textThe mooring Kotelny-T1-13 was deployed in September 2013 at a water depth of ~67 m on the seasonally ice-covered shelf of the northeastern Laptev Sea (Siberian Arctic) and recovered in September 2014. The location of the mooring is characterized by the transport of water masses from the shallow shelf of the Laptev Sea to the Amundsen Basin. The 47 m long mooring was equipped with RDI-Workhorse ADCPs for current measurements and Seabird SBE37 CTDs for temperature and salinity measurements (doi.org/10.1594/PANGAEA.924055). The current was recorded at intervals of 1 m (300 kHz ADCP) and 0.5 m depth (1200 kHz ADCP). The measurement interval was 1 hour. The ADCP current measurements were corrected for declination. The declination was calculated using the Enhanced Magnetic Model (EMM2017 on NOAA.gov.). A total of four moorings (1893, Taymyr, Kotelny, Vilkitsky) were deployed on the shelf of the Laptev Sea in September 2013 during the Transdrift 21 expedition and recovered in September 2014 during Transdrift 22 on board the research vessel Viktor Buinitsky (doi.org/10.1594/PANGAEA.908837). The expeditions were carried out as part of the German-Russian partnership Laptev Sea Systems and the BMBF-funded Transdrift project
Raw data of physical oceanography and current velocity from mooring AK4-1 in the Arctic Ocean in 2015-2018
No full textTime series data of physical oceanography (seawater conductivity, temperature, pressure, salinity) and ocean current velocities were obtained from mooring AK4 in the eastern Arctic Ocean north of Severnaya Zemlya (82.105 °N, 94.772 °W, water depth 1985 m) in 2015 - 2018. The mooring was deployed during Akademik Tryoshnikov expedition AT2015 as part of the NSF-funded NABOS (Nansen and Amundsen Basins Observational System) - program and recovered during AT2018, which was jointly organized between NABOS and the German BMBF-funded CATS (Changing Arctic Transpolar System)-project. The attached archive contains raw data files of Seabird SBE37 microcats, Seabird SBE26 bottom pressure recorders, RDI Acoustic Doppler Current profiler and Aanderaa point current meters. Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable
Raw data of physical oceanography and current velocity from mooring AK5-1 in the Arctic Ocean in 2015-2018
No full textTime series data of physical oceanography (seawater conductivity, temperature, pressure, salinity) and ocean current velocities were obtained from mooring AK5 in the eastern Arctic Ocean north of Severnaya Zemlya (82.224 °N, 94.846 °W, water depth 2398 m) in 2015 - 2018. The mooring was deployed during Akademik Tryoshnikov expedition AT2015 as part of the NSF-funded NABOS (Nansen and Amundsen Basins Observational System) - program and recovered during AT2018, which was jointly organized between NABOS and the German BMBF-funded CATS (Changing Arctic Transpolar System)-project. The attached archive contains raw data files of Seabird SBE37 microcats, Seabird SBE26 bottom pressure recorders, RDI Acoustic Doppler Current profiler and Aanderaa point current meters. Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable
Raw data of physical oceanography and current velocity from mooring AK3-1 in the Arctic Ocean in 2015-2018
No full textTime series data of physical oceanography (seawater conductivity, temperature, pressure, salinity) and ocean current velocities were obtained from mooring AK3 in the eastern Arctic Ocean north of Severnaya Zemlya (81.962 °N, 94.543 °W, water depth 1453 m) in 2015 - 2018. The mooring was deployed during Akademik Tryoshnikov expedition AT2015 as part of the NSF-funded NABOS (Nansen and Amundsen Basins Observational System) - program and recovered during AT2018, which was jointly organized between NABOS and the German BMBF-funded CATS (Changing Arctic Transpolar System)-project. The attached archive contains raw data files of Seabird SBE37 microcats, Seabird SBE26 bottom pressure recorders, RDI Acoustic Doppler Current profiler and Aanderaa point current meters. Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable
Heat loss from the Atlantic water layer in the northern Kara Sea: causes and consequences
Get PDFA distinct, subsurface density front along the eastern St. Anna Trough in the northern Kara Sea is inferred from hydrographic observations in 1996 and 2008–2010. Direct velocity measurements show a persistent northward subsurface current (~ 20 cm s−1) along the St. Anna Trough eastern flank. This sheared flow, carrying the outflow from the Barents and Kara Seas to the Arctic Ocean, is also evident from shipboard observations as well as from geostrophic velocities and numerical model simulations. Although no clear evidence for the occurrence of shear instabilities could be obtained, we speculate that the enhanced vertical mixing along the St. Anna Trough eastern flank promoted by a vertical velocity shear favors the upward heat loss from the intermediate warm Atlantic water layer. The associated upward heat flux is inferred to 50–100 W m−2 using hydrographic data and model simulations. The zone of lowered sea ice thickness and concentration essentially marks the Atlantic water pathway in the St. Anna Trough and adjacent Nansen Basin continental margin from both sea-ice remote sensing observations and model simulations. In fact, the seaice shows a consistently delayed freeze-up onset during fall and a reduction in the seaice thickness during winter. This is consistent with our results on the enhanced Atlantic water heat loss along the Atlantic water pathway in the St. Anna Trough
Current and echo backscatter measurements on the Laptev Sea shelf in 2013-2014 at mooring site Taymyr-T1
No full textThe mooring Taymyr-T1-13 was anchored at a water depth of 59 meters on the seasonally ice-covered shelf of the north-western Laptev Sea. The site is dominated by the on-shelf transport of water from the shelf break. The mooring was equipped with RDI-Workhorse ADCPs for current measurements. The current was recorded at intervals of 1 m (300 kHz ADCP) and 0.5 m depth (1200 kHz ADCP). The measurement interval was 1 hour. The ADCP current measurements were corrected for declination. The declination was calculated using the Enhanced Magnetic Model (EMM2017 on NOAA.gov.). The mooring was deployed in September 2013 during the Transdrift 21 expedition and retrieved in September 2014 during the Transdrift 22 expedition on board the Viktor Buinitsky. The expeditions were carried out as part of the German-Russian partnership Laptev Sea System and the BMBF-funded Transdrift project
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