scholarly journals Ground surface temperature reconstruction for the last 500 years obtained from permafrost temperatures observed in the Stelvio Share borehole, Italian Alps

2017 ◽  
Author(s):  
Mauro Guglielmin ◽  
Marco Donatelli ◽  
Matteo Semplice ◽  
Stefano Serra Capizzano
Keyword(s):  
Little Ice Age ◽  
General Pattern ◽  
Ground Surface ◽  
Temperature Reconstruction ◽  
Ice Age ◽  
European Alps ◽  
Italian Alps ◽  
The Alps ◽  
The Mean ◽  
Mean Annual Air Temperature

Abstract. The general pattern of ground surface temperatures (GST) reconstructed from the permafrost Stelvio Share Borehole (SSB) for the last 500 years are similar to the mean annual air temperature (MAAT) reconstructions for the European Alps. The main difference with respect to MAAT reconstructions relates to post Little Ice Age (LIA) events. Between 1940 and 1989, SSB data indicate a 0.9 °C cooling. Subsequently, a rapid and abrupt GST warming (more than 0.8 °C per decade) was recorded between 1990 and 2011. This warming is of the same magnitude as the increase of MAAT between 1990 and 2000 recorded in central Europe and roughly double the MAAT in the Alps.

scholarly journals Ground surface temperature reconstruction for the last 500 years obtained from permafrost temperatures observed in the SHARE STELVIO Borehole, Italian Alps

2018 ◽  
Vol 14 (6) ◽  
pp. 709-724 ◽  
Author(s):  
Mauro Guglielmin ◽  
Marco Donatelli ◽  
Matteo Semplice ◽  
Stefano Serra Capizzano
Keyword(s):  
General Pattern ◽  
Ground Surface ◽  
Temperature Reconstruction ◽  
Ice Age ◽  
European Alps ◽  
Italian Alps ◽  
Heat Effects ◽  
Penalty Operator ◽  
The Alps ◽  
Different Depths

Abstract. Here we present the results of the inversion of a multi-annual temperature profile (2013, 2014, 2015) of the deepest borehole (235 m) in the mountain permafrost of the world located close to Stelvio Pass in the Central Italian Alps. The SHARE STELVIO Borehole (SSB) has been monitored since 2010 with 13 thermistors placed at different depths between 20 and 235 m. The negligible porosity of the rock (dolostone,  <  5 %) allows us to assume the latent heat effects are also negligible. The inversion model proposed here is based on the Tikhonov regularization applied to a discretized heat equation, accompanied by a novel regularizing penalty operator. The general pattern of ground surface temperatures (GSTs) reconstructed from SSB for the last 500 years is similar to the mean annual air temperature (MAAT) reconstructions for the European Alps. The main difference with respect to MAAT reconstructions relates to post Little Ice Age (LIA) events. Between 1940 and 1989, SSB data indicate a cooling of ca. 1 °C. Subsequently, a rapid and abrupt GST warming (more than 0.8 °C per decade) was recorded between 1990 and 2011. This warming is of the same magnitude as the increase in MAAT between 1990 and 2000 recorded in central Europe and roughly doubling the increase in MAAT in the Alps.

scholarly journals No role for industrial black carbon in forcing 19th century glacier retreat in the Alps

2018 ◽  
Author(s):  
Michael Sigl ◽  
Nerilie J. Abram ◽  
Jacopo Gabrieli ◽  
Theo M. Jenk ◽  
Dimitri Osmont ◽  
...  
Keyword(s):  
Black Carbon ◽  
19Th Century ◽  
Little Ice Age ◽  
Radiative Forcing ◽  
Ice Cores ◽  
Ambient Air ◽  
Radiative Properties ◽  
Ice Age ◽  
European Alps ◽  
The Alps

Abstract. Light absorbing aerosols in the atmosphere and cryosphere play an important role in the climate system. Their presence in ambient air and snow changes radiative properties of these media, thus contributing to increased atmospheric warming and snowmelt. High spatio-temporal variability of aerosol concentrations and a shortage of long-term observations contribute to large uncertainties in properly assigning the climate effects of aerosols through time. Starting around 1860 AD, many glaciers in the European Alps began to retreat from their maximum mid-19th century terminus positions, thereby visualizing the end of the Little Ice Age in Europe. Radiative forcing by increasing deposition of industrial black carbon to snow has been suggested as the main driver of the abrupt glacier retreats in the Alps. Basis for this hypothesis were model simulations using elemental carbon concentrations at low temporal resolution from two ice cores in the Alps. Here we present sub-annually resolved, well-replicated concentration records of refractory black carbon (rBC; using soot photometry) as well as distinctive tracers for mineral dust, biomass burning and industrial pollution from the Colle Gnifetti ice core in the Alps from 1741–2015 AD. These records allow precise assessment of a potential relation between the timing of observed acceleration of glacier melt in the mid-19th century with an increase of rBC deposition on the glacier caused by the industrialization of Western Europe. Our study reveals that in 1875 AD, the time when European rBC emission rates started to significantly increase, the majority of Alpine glaciers had already experienced more than 80 % of their total 19th century length reduction. Industrial BC emissions can, therefore, not been considered as the primary forcing for the rapid deglaciation at the end of the Little Ice Age in the Alps. BC records from the Alps and Greenland also reveal the limitations of bottom-up emission inventories to represent a realistic evolution of anthropogenic BC emissions since preindustrial times.

scholarly journals Little Ice Age glacier history of the Central and Western Alps from pictorial documents

2018 ◽  
Vol 44 (1) ◽  
pp. 115 ◽  
Author(s):  
H.J. Zumbühl ◽  
S.U. Nussbaumer
Keyword(s):  
Little Ice Age ◽  
Western Alps ◽  
Ice Age ◽  
European Alps ◽  
Huge Number ◽  
Valley Bottom ◽  
Valley Glacier ◽  
History Of ◽  
The Alps ◽  
The 19Th Century

The Lower Grindelwald Glacier (Bernese Oberland, Switzerland) consists of two parts, the Ischmeer in the east (disconnected) and the Bernese Fiescher Glacier in the west. During the Little Ice Age (LIA), the glacier terminated either in the area of the “Schopffelsen” (landmark rock terraces) or advanced at least six times (ten times if we include early findings) even further down into the valley bottom forming the “Schweif” (tail). Maximal ice extensions were reached in 1602 and 1855/56 AD. The years after the end of the LIA have been dominated by a dramatic melting of ice, especially after 2000. The Mer de Glace (Mont Blanc area, France) is a compound valley glacier formed by the tributaries Glacier du Tacul, Glacier de Léschaux, and Glacier de Talèfre (disconnected). During the LIA, the Mer de Glace nearly continuously reached the plain in the Chamonix Valley (maximal extensions in 1644 and 1821 AD). The retreat, beginning in the mid-1850s, was followed by a relatively stable position of the front (1880s until 1930s). Afterwards the retreat has continued until today, especially impressive after 1995. The perception of glaciers in the early times was dominated by fear. In the age of Enlightenment and later in the 19th century, it changed to fascination. In the 20th century, glaciers became a top attraction of the Alps, but today they are disappearing from sight. With a huge number of high-quality pictorial documents, it is possible to reconstruct the LIA history of many glaciers in the European Alps from the 17th to the 19th centuries. Thanks to these pictures, we get an image of the beauty and fascination of LIA glaciers, ending down in the valleys. The pictorial documents (drawings, paintings, prints, photographs, and maps) of important artists (Caspar Wolf, Jean-Antoine Linck, Samuel Birmann) promoted a rapidly growing tourism. Compared with today’s situations, it gives totally different landscapes – a comparison of LIA images with the same views of today is probably the best visual proof for the changes in climate.

Glacial reduction in the Gran Paradiso Massif (Western Italian Alps): multitemporal dynamic inventory since the Little Ice Age

2020 ◽  
Author(s):  
Simona Gennaro ◽  
Maria Cristina Salvatore ◽  
Linda Alderighi ◽  
Riccardo Cerrato ◽  
Carlo Baroni
Keyword(s):  
Little Ice Age ◽  
Quantitative Data ◽  
Reduction Rate ◽  
Temporal Analysis ◽  
Ice Age ◽  
European Alps ◽  
Italian Alps ◽  
Multi Temporal ◽  
Gran Paradiso ◽  
The Impact

&lt;p&gt;Alpine glaciers are sensitive key markers of climate variations, as their geometry and shape are the results of adjustments in response to changes of their mass balance. Since the Little Ice Age the European Alps, as well as other mountain ranges, experienced a phase of generalized retreat, accentuated during the last decades. The availability of quantitative data on glaciers variations from major mountain regions represent relevant tools for better understanding the glacier behaviour in response to ongoing climatic changes. Here we present new data on Holocenic variations of glaciers hosted in the Gran Paradiso Massif, the first Italian National Park (Western Italian Alps).&lt;/p&gt;&lt;p&gt;We built the multi-temporal digital inventory of the Gran Paradiso Massif glaciers covering a time period of over 150 years, considering distinct time steps spanning from the Little Ice Age (LIA) to 2015. The multi-temporal dataset was built including glaciers outlines (derived from high resolution orthophotos and historical maps) and the data related to frontal variations (coming from annual glaciological surveys conducted by the Italian Glaciological Committee). Database was managed in GIS environment and populated following the guidelines suggested by the WGMS. Multi-temporal analysis supplied new quantitative data on the strong glacial decline occurred since the LIA and dramatically accelerated since the 90s.&lt;/p&gt;&lt;p&gt;During the LIA the Gran Paradiso Massif hosted more than 120 glaciers extended for about 112 km&lt;sup&gt;2&lt;/sup&gt; reduced to 73 units in 2015 covering only about 32 km&lt;sup&gt;2&lt;/sup&gt;.&lt;/p&gt;&lt;p&gt;Our data underline a loss of about 50 &amp;#177; 4 m w.e. and ELA variations of about 166/130 &amp;#177; 5/4 m (considering AAR/AABR methods, respectively) from the maximum LIA position and 2006. The strong contraction and fragmentation of the studied glaciers is underlined by area loss of over 71% (with a reduction rate of -0.36% y&lt;sup&gt;-1&lt;/sup&gt;) from the LIA to 2015, as well as by the increase in the number of glacial bodies smaller than 0.1 km&lt;sup&gt;2&lt;/sup&gt;, and by the increase in the number of extinct glaciers (33 in 2015 respect to 1957). Furthermore, during the last decades, new data obtained show a dramatic acceleration in the contraction rates of the glacial bodies, which can lead to impressive landscape changes and to a relevant increase of geomorphological hazard.&lt;/p&gt;&lt;p&gt;The multitemporal data show a very detailed evolution of Gran Paradiso glaciers also considering ice- mass loss and can contribute to modelling glaciers response to climate changes in a sensitive area of the Italian Alps, considering its location at the border of a &amp;#8220;dry zone&amp;#8221;. Improving the knowledge on the glacial resource could contribute in better understanding the impact of warming climate on mountain hydrology, as well as to increase the awareness of the population and authorities to be resilient in a near future with strong reduction of meltwater runoff.&lt;/p&gt;

scholarly journals A 368-year maximum temperature reconstruction based on tree-ring data in the northwestern Sichuan Plateau (NWSP), China

2016 ◽  
Vol 12 (7) ◽  
pp. 1485-1498 ◽  
Author(s):  
Liangjun Zhu ◽  
Yuandong Zhang ◽  
Zongshan Li ◽  
Binde Guo ◽  
Xiaochun Wang
Keyword(s):  
Tree Ring ◽  
Land Surface ◽  
Temperature Reconstruction ◽  
Temperature Variability ◽  
Ice Age ◽  
Maximum Temperature ◽  
Tree Ring Data ◽  
The Mean ◽  
Extreme Cold ◽  
The 19Th Century

Abstract. We present a reconstruction of July–August mean maximum temperature variability based on a chronology of tree-ring widths over the period AD 1646–2013 in the northern part of the northwestern Sichuan Plateau (NWSP), China. A regression model explains 37.1 % of the variance of July–August mean maximum temperature during the calibration period from 1954 to 2012. Compared with nearby temperature reconstructions and gridded land surface temperature data, our temperature reconstruction had high spatial representativeness. Seven major cold periods were identified (1708–1711, 1765–1769, 1818–1821, 1824–1828, 1832–1836, 1839–1842, and 1869–1877), and three major warm periods occurred in 1655–1668, 1719–1730, and 1858–1859 from this reconstruction. The typical Little Ice Age climate can also be well represented in our reconstruction and clearly ended with climatic amelioration at the late of the 19th century. The 17th and 19th centuries were cold with more extreme cold years, while the 18th and 20th centuries were warm with less extreme cold years. Moreover, the 20th century rapid warming was not obvious in the NWSP mean maximum temperature reconstruction, which implied that mean maximum temperature might play an important and different role in global change as unique temperature indicators. Multi-taper method (MTM) spectral analysis revealed significant periodicities of 170-, 49–114-, 25–32-, 5.7-, 4.6–4.7-, 3.0–3.1-, 2.5-, and 2.1–2.3-year quasi-cycles at a 95 % confidence level in our reconstruction. Overall, the mean maximum temperature variability in the NWSP may be associated with global land–sea atmospheric circulation (e.g., ENSO, PDO, or AMO) as well as solar and volcanic forcing.

scholarly journals Glacier equilibrium line altitude variations during the “Little Ice Age” in the Mediterranean Andes (30◦–37◦ S)

2019 ◽  
Author(s):  
Álvaro González-Reyes ◽  
Claudio Bravo ◽  
Mathias Vuille ◽  
Martin Jacques-Coper ◽  
Maisa Rojas ◽  
...  
Keyword(s):  
Little Ice Age ◽  
Pearson Correlation ◽  
Temporal Changes ◽  
Global Climate Models ◽  
Ice Age ◽  
Equilibrium Line ◽  
Equilibrium Line Altitude ◽  
Mountainous Regions ◽  
The Mean ◽  
The Mediterranean

Abstract. The "Little Ice Age" (LIA; 1500–1850 Common Era (CE)), has long been recognized as the last period when mountain glaciers in many regions of the Northern Hemisphere (NH) recorded extensive growth intervals in terms of their ice mass and frontal position. The knowledge about this relevant paleoclimatic interval is vast in mountainous regions such as the Alps and Rocky Mountains in North America. However, in extra-tropical Andean sub-regions such as the Mediterranean Andes of Chile and Argentina (MA; 30º–37º S), the LIA has been poorly documented. Paradoxically, the few climate reconstructions performed in the MA based on lake sediments and tree rings do not show clear evidence of a LIA climate anomaly as observed in the NH. In addition, recent studies have demonstrated temporal differences between mean air temperature variations across the last millennium between both hemispheres. This motivates our hypothesis that the LIA period was not associated with a significant climate perturbation in the MA region. Considering this background, we performed an experiment using daily climatic variables from three Global Climate Models (GCMs) to force a novel glaciological model. In this way, we simulated temporal variations of the glacier equilibrium-line altitude (ELA) to evaluate the glacier response during the period 1500–1848 CE. Overall, each GCM shows temporal changes in annual ELA, with anomalously low elevations during 1640–1670 and 1800–1848 CE. An interval with high ELA values was identified during 1550–1575 CE. The spectral properties of the mean annual ELA in each GCM present significant periodicities between 2–7 years, and also significant decadal to multi-decadal signals. In addition, significant and coherent cycles at interannual to multi-decadal scales were detected between modeled mean annual ELAs and the first EOF1 extracted from Sea Surface Temperature (SST) within the El Niño 3.4 of each GCM. Finally, significant Pearson correlation coefficients were obtained between the mean annual ELA and Pacific SST on interannual to multi-decadal timescales. According to our findings, we propose that Pacific SST variability was the main modulator of temporal changes of the ELA in the MA region of South America during 1500–1848 CE.

scholarly journals Bodengeographische Beobachtungen zur pleistozänen und holozänen Vergletscherung des Westlichen Tienshan (Usbekistan)

1996 ◽  
Vol 46 (1) ◽  
pp. 144-151
Author(s):  
Wolfgang Zech ◽  
Rupert Bäumler ◽  
Oksana Savoskul ◽  
Anatoli Ni ◽  
Maxim Petrov
Keyword(s):  
Little Ice Age ◽  
Late Glacial ◽  
Ice Age ◽  
Lower Side ◽  
Glacial Ice ◽  
Middle Holocene ◽  
Glacial Origin ◽  
Weathered Soils ◽  
Recent Origin ◽  
The Alps

Abstract. Soil geographic studies were carried out in the Oigaing valley between Ugamsky and Pskemsky range NE of Tashkent (W-Tienshan, Republic of Uzbekistan) with special regard to the Pleistocene and Holocene glaciation. Clear end moraines of the last main glaciation are preserved at the junction of Maidan and Oigaing river at 1500-1600 m a.s.l. They show intensively weathered soils with a depth of more than 80 cm. Similar deposits ol presumably Pleistocene or late glacial origin are also located upvalley at the embouchure of numerous side valleys (Beschtor, Tekesch, Aütor) into the main valley of Oigaing. All side valleys are characterized by late glacial ground and end moraines in 2500-2700 m a.s.l. showing intensively weathered brown colored soils of 30-40 cm depth. Further moraines of Holocene or recent origin are located approach of the recent glaciers which descend to 3000-3200 m. They show shallow, initial soils, and presumably correspond with glacial advances during the so-called "Little Ice Age" with a maximum advance at about 1850 in the Alps, and in the middle Holocene at about 2000 or 4000 a BP. Highly weathered, and rubefied interglacial soils developed from old Quaternary gravel are preserved above high glacial ice marginal grounds of the last main glaciation (>2850 m a.s.l.) in the lower side valley of the Barkrak river. In the upper valley huge drift could be shown above the ice marginal grounds, but without typical forms of morainic deposits. They give evidence for older glaciations with a greater extent compared with the last main glaciation. However, no corresponding moraines are present in the working area.

scholarly journals The ENSO teleconnections to the Indian summer monsoon climate through the Last Millennium as simulated by the PMIP3

2018 ◽  
Author(s):  
Charan Teja Tejavath ◽  
Karumuri Ashok ◽  
Supriyo Chakraborty ◽  
Rengaswamy Ramesh
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Little Ice Age ◽  
Walker Circulation ◽  
Summer Monsoon Rainfall ◽  
Ice Age ◽  
Boreal Summer ◽  
Last Millennium ◽  
Enso Teleconnections ◽  
The Mean

Abstract. Using seven model simulations from the PMIP3, we study the mean summer (June–September) climate and its variability in India during the Last Millennium (LM; CE 850–1849) with emphasis on the Medieval Warm Period (MWP) and Little Ice Age (LIA), after validation of the simulated current day climate and trends. We find that the above (below) LM-mean summer global temperatures during the MWP (LIA) are associated with relatively higher (lower) number of concurrent El Niños as compared to La Niñas. The models simulate higher (lower) Indian summer monsoon rainfall (ISMR) during the MWP (LIA). This is notwithstanding a strong simulated negative correlation between the timeseries of NINO3.4 index and that of the area-averaged ISMR, Interestingly, the percentage of strong El Niños (La Niñas) causing negative (positive) ISMR anomalies is higher in the LIA (MWP), a non-linearity that apparently is important for causing higher ISMR in the MWP. Distribution of simulated boreal summer velocity potential at 850 hPa during MWP in models, in general, shows a zone of anomalous convergence in the central tropical Pacific flanked by two zones of divergence, suggesting a westward shift in the Walker circulation as compared to the simulations for LM as well as and a majority of historical simulations, and current day observed signal. The anomalous divergence centre in the west also extends into the equatorial eastern Indian Ocean, resulting in an anomalous convergence zone over India and therefore excess rainfall during the MWP as compared to the LM; the results are qualitative, given the inter-model spread.

The Claps of Luc-en-Diois (Drôme, SE France) : evaluation of a lake fill volume based on a morphological model

2004 ◽  
Vol 175 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Gilles Brocard
Keyword(s):  
Little Ice Age ◽  
River Sediment ◽  
Sediment Load ◽  
Ice Age ◽  
Drainage Network ◽  
Erosion Rates ◽  
Lake Volume ◽  
Fill Volume ◽  
Morphological Model ◽  
The Mean

Abstract The Claps Lake near Luc-en-Diois is a naturally dammed palaeo-lake fed by the Drôme River sediment load during the Little Ice Age (LIA). The present assessment is based on a valley reconstruction using a geomorphic model. It illustrates the potentiality and limits of the geomorphic analysis to accurately predict the buried topography. This method indeed may help to reduce the prospecting work required in classical evaluations of fill volumes of such natural dams. The lake was rapidly filled with sediments, indicating enhanced erosion of the watershed during the LIA. Several studies have attempted to quantify the volume of the lake fill and use it to assess erosion rates during the LIA. Very little is known, however, about the geometry of the buried valley. Estimated lake volumes and erosion rates vary depending on how the buried valley is reconstructed and what correcting factors are used for calculating erosion rates. The present assessment is based on a valley reconstruction using a geomorphic model calibrated by the surrounding drainage network, as well as the introduction of correcting factors that improve the corrections applied in the previous works. The resulting lake volume is 71–81.106 m3, and the mean erosion rate at 0.7-1.2 mm.yr-1, a high value compared to previous estimates. This rate is compared to the results obtained by various methods and over different timescales in the surrounding region.

scholarly journals Temperature and mineral dust variability recorded in two low-accumulation Alpine ice cores over the last millennium

2018 ◽  
Vol 14 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Pascal Bohleber ◽  
Tobias Erhardt ◽  
Nicole Spaulding ◽  
Helene Hoffmann ◽  
Hubertus Fischer ◽  
...  
Keyword(s):  
Time Series ◽  
Mineral Dust ◽  
Ice Core ◽  
Ice Cores ◽  
Temperature Reconstruction ◽  
Relative Increase ◽  
Ice Age ◽  
European Alps ◽  
Stable Water Isotopes ◽  
Annual Layer

Abstract. Among ice core drilling sites in the European Alps, Colle Gnifetti (CG) is the only non-temperate glacier to offer climate records dating back at least 1000 years. This unique long-term archive is the result of an exceptionally low net accumulation driven by wind erosion and rapid annual layer thinning. However, the full exploitation of the CG time series has been hampered by considerable dating uncertainties and the seasonal summer bias in snow preservation. Using a new core drilled in 2013 we extend annual layer counting, for the first time at CG, over the last 1000 years and add additional constraints to the resulting age scale from radiocarbon dating. Based on this improved age scale, and using a multi-core approach with a neighbouring ice core, we explore the time series of stable water isotopes and the mineral dust proxies Ca2+ and insoluble particles. Also in our latest ice core we face the already known limitation to the quantitative use of the stable isotope variability based on a high and potentially non-stationary isotope/temperature sensitivity at CG. Decadal trends in Ca2+ reveal substantial agreement with instrumental temperature and are explored here as a potential site-specific supplement to the isotope-based temperature reconstruction. The observed coupling between temperature and Ca2+ trends likely results from snow preservation effects and the advection of dust-rich air masses coinciding with warm temperatures. We find that if calibrated against instrumental data, the Ca2+-based temperature reconstruction is in robust agreement with the latest proxy-based summer temperature reconstruction, including a “Little Ice Age” cold period as well as a medieval climate anomaly. Part of the medieval climate period around AD 1100–1200 clearly stands out through an increased occurrence of dust events, potentially resulting from a relative increase in meridional flow and/or dry conditions over the Mediterranean.

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