Synoptic drivers of 400 years of summer temperature and precipitation variability on Mt. Olympus,Greece     

Stefan?KlesseEmail author  Malin?Ziehmer  Georgios?Rousakis  Valerie?Trouet  David?Frank 《Climate Dynamics》2015,44(3-4):807-825

The Mediterranean region has been identified as a global warming hotspot, where future climate impacts are expected to have significant consequences on societal and ecosystem well-being. To put ongoing trends of summer climate into the context of past natural variability, we reconstructed climate from maximum latewood density (MXD) measurements of Pinus heldreichii (1521–2010) and latewood width (LWW) of Pinus nigra (1617–2010) on Mt. Olympus, Greece. Previous research in the northeastern Mediterranean has primarily focused on inter-annual variability, omitting any low-frequency trends. The present study utilizes methods capable of retaining climatically driven long-term behavior of tree growth. The LWW chronology corresponds closely to early summer moisture variability (May–July, r = 0.65, p < 0.001, 1950–2010), whereas the MXD-chronology relates mainly to late summer warmth (July–September, r = 0.64, p < 0.001; 1899–2010). The chronologies show opposing patterns of decadal variability over the twentieth century (r = ?0.68, p < 0.001) and confirm the importance of the summer North Atlantic Oscillation (sNAO) for summer climate in the northeastern Mediterranean, with positive sNAO phases inducing cold anomalies and enhanced cloudiness and precipitation. The combined reconstructions document the late twentieth—early twenty-first century warming and drying trend, but indicate generally drier early summer and cooler late summer conditions in the period ~1700–1900 CE. Our findings suggest a potential decoupling between twentieth century atmospheric circulation patterns and pre-industrial climate variability. Furthermore, the range of natural climate variability stretches beyond summer moisture availability observed in recent decades and thus lends credibility to the significant drying trends projected for this region in current Earth System Model simulations.  相似文献   

Magnetotactic bacteria from the human gut microbiome associated with orientation and navigation regions of the brain     

Simon  Rozalyn A.  Ranasinghe  Purnika Damindi  Barazanji  Nawroz  Jungeström  Malin Bergman  Xu  Jie  Bednarska  Olga  Serrander  Lena  Engström  Maria  Bazylinski  Dennis A.  Keita  Åsa V.  Walter  Susanna 《中国海洋湖沼学报》2021,39(6):2044-2052

Journal of Oceanology and Limnology - Magnetotactic bacteria (MTB), ubiquitous in soil and fresh and saltwater sources have been identified in the microbiome of humans and many animals. MTB...  相似文献   

Geomagnetic lunar analysis—the estimation of errors     

R. Sellek  S. R. C. Malin 《Geophysical Journal International》1982,70(3):793-796

Summary. It has recently been proposed that a reliable estimate of the errors of tidal harmonics present in geomagnetic data can be obtained by the following method: (1) randomly assign each observation to one of 10 subsets, (2) determine the tidal harmonics separately for each subset, and (3) calculate the standard deviation of the mean from the scatter among the 10 determinations. This method is valid if the subsets are statistically independent, but will lead to an underestimate of the errors if they are not. Here we show that, for real geomagnetic data, the assumption of statistical independence is valid.  相似文献   

Computation of the Solution of Geomagnetic Induction Problems: a General Method, with Applications     

V. C. L. Hutson  P. C. Kendall  S. R. C. Malin 《Geophysical Journal International》1972,28(5):489-498

  相似文献   

Regional operational and environmental performance evaluation in China: non-radial DEA methodology under natural and managerial disposability   总被引：1，自引：1，他引：0  

Song  Malin  Zhang  Guijun  Fang  Kuangnan  Zhang  Jing 《Natural Hazards》2015,75(1):243-263

In this article, we used a non-radial DEA under natural and managerial disposability to measure the unified efficiency of 30 administrative regions in China and then evaluated their operational and environmental performances. We proposed the performance progress unified index (PPUI) based on the non-radial DEA methodology in a time horizon under natural and managerial disposability with a crossover to measure the performance variety of DMUs. The results of the unified efficiency measured under natural and managerial disposability showed that both operational and environmental performance in eastern China were the highest among the three regions during 2000–2011. The PPUIs under natural and managerial disposability indicated that the operational and environmental performance of the three regions improved during 2000–2011, and the rate of operational and environmental performance of eastern China was higher than the other two regions.

  相似文献   

Geochemical responses to paleoclimatic changes in southern Sweden since the late glacial: the Hässeldala Port lake sediment record     

Malin E. Kylander  Jonatan Klaminder  Barbara Wohlfarth  Ludvig Löwemark 《Journal of Paleolimnology》2013,50(1):57-70

There is a relatively good understanding of the paleoenvironmental changes that have occurred in southern Sweden since the Late Glacial. A main exception, however, is the sedimentary response of lacustrine systems during this period of rapid climate shifts. To address this, high-resolution X-ray fluorescence core scanning, Total Organic Carbon (TOC), C/N and δ¹³C analyses were made on a core from Hässeldala Port, a paleolake in the region. Site-specific geochemical analyses documented variations in silicate inputs (Zr/Ti, Si/Ti, K/Ti and K/Rb), productivity (TOC, Ca/Ti and Sr/Ti), as well as redox conditions in the sediment (δ¹³C, Mn/Ti and Fe/Ti), which were then linked to the regional climatic framework. During the Bølling/Older Dryas sediment accumulation was at its highest, particularly prior to colonization by terrestrial vegetation, and hydrological transport dominated. No clear signal of the Older Dryas was detected in the elemental chemistry. The Allerød was a period of relatively constant sediment accumulation, with the exception of during the Gerzensee oscillation when rates increased. There is evidence for increased within-lake and -catchment productivity and a change in silicate source during parts of the Allerød. As opposed to other records from the region, constant sediment accumulation rates were found during the Younger Dryas. Other proxies also suggest that this was a rather static period at Hässeldala Port. A gradual change in productivity and hydrological activity was observed from 12,000 cal year BP. The Preboreal section is rather short but the geochemical response was similar to that seen during other periods with milder climate conditions. The geochemical record archived in the sediments at Hässeldala Port was found to be the integrated result of physical erosion, landscape and soil development, vegetation changes, basin hydrology and moisture and temperature variations and it fills an important information gap in our understanding of the geochemical response of lake sediments to past climate change.  相似文献   

Constraining explosive volcanism: subjective choices during estimates of eruption magnitude   总被引：2，自引：1，他引：1  

Malin Klawonn  Bruce F. Houghton  Donald A. Swanson  Sarah A. Fagents  Paul Wessel  Cecily J. Wolfe 《Bulletin of Volcanology》2014,76(2):1-6

When estimating the magnitude of explosive eruptions from their deposits, individuals make three sets of critical choices with respect to input data: the spacing of sampling sites, the selection of contour intervals to constrain the field measurements, and the hand contouring of thickness/isomass data, respectively. Volcanologists make subjective calls, as there are no accepted published protocols and few accounts of how these choices will impact estimates of eruption magnitude. Here, for the first time, we took a set of unpublished thickness measurements from the 1959 Kīlauea Iki pyroclastic fall deposit and asked 101 volcanologists worldwide to hand contour the data. First, there were surprisingly consistent volume estimates across maps with three different sampling densities. Second, the variability in volume calculations imparted by individuals’ choices of contours is also surprisingly low and lies between s?=?5 and 8 %. Third, volume estimation is insensitive to the extent to which different individuals “smooth” the raw data in constructing contour lines. Finally, large uncertainty is associated with the construction of the thinnest isopachs, which is likely to underestimate the actual trend of deposit thinning. The net result is that researchers can have considerable confidence in using volume or dispersal data from multiple authors and different deposits for comparative studies. These insights should help volcanologists around the world to optimize design and execution of field-based studies to characterize accurately the volume of pyroclastic deposits.  相似文献   

Erratum to: Spatial variability in DMSP-lyase activity along an Atlantic meridional transect     

Thomas G. Bell  Gill Malin  Young-Nam Kim  Michael Steinke 《Aquatic Sciences - Research Across Boundaries》2010,72(4):533-535

  相似文献   

Cover Image          下载免费PDF全文

Bradley W. Goodfellow  Giulio Viola  Bernard Bingen  Perach Nuriel  Andrew R.C. Kylander‐Clark 《地学学报》2017,29(5):i-i

  相似文献   

Palaeocene faulting in SE Sweden from U–Pb dating of slickenfibre calcite          下载免费PDF全文

Bradley W. Goodfellow  Giulio Viola  Bernard Bingen  Perach Nuriel  Andrew R.C. Kylander‐Clark 《地学学报》2017,29(5):321-328

Estimating the timing of faulting is crucial to modelling tectonics, palaeoseismicity, landscape evolution and fault mechanics. Four slickenfibre calcite samples from a conjugate strike‐slip fault set in a platformal limestone, SE Sweden, were dated using U–Pb. Three of the samples yielded an average age of 64.8 ± 6.5 Ma, while the fourth yielded a marginally younger age of 54.7 ± 5.5 Ma. Precipitation of the fibres is interpreted as syn‐deformational. Age uncertainty and dispersion reflect incorporation of common Pb and tiny host‐rock components into the dated calcite and/or possible fault reactivation through ca. 55 Ma. We infer from crystal characteristics, stable isotopes (δ¹⁸O and δ¹³C) and rare‐earth elements that fibres formed in an environment rich in deep‐seated fluids, at temperatures of 40–200°C, with shear stresses exceeding 10 MPa and at a maximum burial depth of c. 4 km. This Palaeocene faulting may reflect far‐field stresses from shortening in the Alps.  相似文献