| 1. |
|
|
| 2. |
- Dahl-Jensen, D., et al.
(författare)
-
Eemian interglacial reconstructed from a Greenland folded ice core
- 2013
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 493:7433, s. 489-494
-
Tidskriftsartikel (refereegranskat)abstract
- Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 +/- 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 +/- 250 metres, reaching surface elevations 122,000 years ago of 130 +/- 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.
|
|
| 3. |
- Guðlaugsdóttir, H., et al.
(författare)
-
The influence of volcanic eruptions on weather regimes over the North Atlantic simulated by ECHAM5/MPI-OM ensemble runs from 800 to 2000 CE
- 2018
-
Ingår i: Atmospheric Research. - : Elsevier BV. - 0169-8095. ; 213, s. 211-223
-
Tidskriftsartikel (refereegranskat)abstract
- The volcanic fingerprint on the winter North Atlantic atmospheric circulation and climate is analyzed in six ensemble runs of ECHAM5/MPI-OM covering 800–2000 CE, both for equatorial and Northern Hemisphere (NH) eruptions. Large volcanic eruptions influence climate on both annual and decadal time scales due to dynamic interactions of different climate components in the Earth's system. It is well known that the North Atlantic Oscillation (NAO) tends to shift towards its positive phase during winter in the first 1–2 years after large tropical volcanic eruptions, causing warming over Europe, but other North Atlantic weather regimes have received less attention. Here we investigate the four dominant weather regimes in the North Atlantic: The negative and positive phase of NAO as well as the Atlantic Ridge, Scandinavian blocking. The volcanic fingerprint is detected as a change in the frequency of occurrence and anomalies in the wind and temperature fields as well as in the sea ice cover. We observe a strong significant increase in the frequency of Atlantic Ridge in the second year after equatorial eruptions that precede the NAO+ detected in year 3–5 as a result of a strong zonal wind anomalies in year 1–2. Evidence for a stronger polar vortex is detected in years 12–14 where NAO+ is detected both as a frequency increase and in the wind and temperature fields. A short-term response is also detected 2–4 years after NH eruptions. The longterm signal after NH eruptions indicate a weak polar vortex around a decade after an eruption. Although the signal after NH eruptions is weaker our results stress the need for further studies. The simulated atmospheric response recorded in ECHAM5 after volcanic eruptions suggest a more dynamic response than previously thought. The methodology used can also be applied to other forcing scenario, for example for future climate projections where the aim is to search for a long-term climate signal.
|
|
| 4. |
- Ademuyiwa, Adesoji O., et al.
(författare)
-
Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
-
Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
|
|
