the north atlantic jet stream a look at preferred positions paths and transitions preferred jet stream positions and their link to regional circulation patterns over the winter north atlantic european sector are investigated to corroborate findings of multimodal behaviour of the

regionally differentiated contribution of mountain glaciers and ice caps to future sea level rise the contribution to sea level rise from mountain glaciers and ice caps has grown over the past decades a projection of their melting during the twenty first century based on temperature and precipitation projections from ten climate models suggests that by 2100 these glaciers will lose about 21 of their total global volume

persistent circulation regimes and preferred regime transitions in the north atlantic the persistent regime behavior of the eddy driven jet stream over the north atlantic is investigated the north atlantic jet stream variability is characterized by the latitude of the maximum lower tropospheric wind speedofthe40 yrecmwfre analysis era 40 datafortheperiod1december1957 28february2002 a hidden markov model hmm analysis reveals that the jet stream exhibits three persistent regimes that correspond to northern southern and central jet states the regime states are closely related to the north atlantic oscillation and the eastern atlantic teleconnection pattern the regime states are associated with distinct changes in the storm tracks and the frequencyof occurrence of cyclonic and anticyclonic rossbywave breaking three preferred regime transitions are identified namely southern to central jet northern to southern jet and central to northern jet the preferred transitions can be interpreted as a preference for poleward propagation of the jet but with the southern jet state entered via a dramatic shift from the northern state evidence is found that wave breaking is involved in two of the three preferred transitions northern to southern jet and central to northern jet transitions the predictability characteristics and the interannual variability in the frequency of occurrence of regimes are also discussed

do seismic reflections necessarily have chronostratigraphic significance many seismic reflections from within sedimentary successions are thought to be generated along stratal surfaces because those surfaces are laterally continuous and have marked acoustic impedance contrasts as stratal surfaces are isochronous those reflections are then also taken as being chronostratigraphically significant in contrast seismic reflections are thought not to be generated along the boundaries of lithostratigraphic units because those boundaries are discontinuous and gradational nevertheless synthetic seismic analysis shows that seismic reflections should in many circumstances be expected to follow lithostratigraphic unit boundaries not stratal surfaces as these lithostratigraphic unit boundaries will generally be diachronous seismic reflections from within sedimentary successions should evidently not be treated as necessarily having chronostratigraphic significance

fault scarps and deformation rates in lazio abruzzo central italy comparison between geological fault slip rate and gps data abstract we compare new and literature data concerning the integrated deformation rate since 18 ka for the central apennines with deformation rate data derived from a 6 year gps campaign we constructed topographic profiles across the majority of the active faults in the area we derived deformation rate data from displaced post glacial sediments and slopes associated with the last major glacial retreat that occurred in the region about 18 kyr ago paleoseismic investigations in this region clearly show that offset of these features is the cumulative effect of repeated surface faulting earthquakes with magnitudes in the range 5 5 ms 7 0 a cumulative throw rate diagram incorporating both our values and the values extracted from the literature i e previously published trenching studies scarp profiles and offset terraces is presented providing a regional picture of the spatial deformation rate distribution in the central apennines during the latest pleistocene and holocene by converting cumulative throw rates into heave rates we calculate maximum extension rates of ca 2 mm year at the location of the same transect where 6 2 mm year has been measured with gps over 6 years this discrepancy between geodetic and geological fault slip rate data implies that we have to be cautious whenever we use gps data for seismic hazard assessment purposes or when attempting to reconstruct the tectonic processes in an area because geodetic data may be unrepresentative of the longer term deformation rates on the other hand this discrepancy may provide insights into the mechanics of the seismic cycle we discuss various scenarios that may explain the mis match between long term and short term measurements

europe s southernmost glaciers response and adaptation to climate change the southernmost glaciers in europe are located on the iberian apennine and balkan peninsulas in mid latitudes between 41 n and 44 n at altitudes ranging from 2000 to 3000 m a s l all these glaciers are a legacy of the little ice age lia they survive in a relatively warm environment mean annual temperature 0 ct o 1 c due to local topographic controls and high levels of accumulation as a result of avalanche and wind blown snow in the pirin mountains bulgaria snezhnika glacieret has been cored providing an archive of recent climate change small glaciers such as this respond quickly to climatic extremes since the lia maximum during the 19th century all southern european glaciers have retreated losing 30 100 of their volume however despite the trend towards warmer years since the late 1970s some glaciers still survive even after some of the hottest summers on record predicted future warming especially in summer and drier conditions in the mediterranean basin may result in the disappearance of all glacier features at these latitudes in europe within the next few decades

ensemble prediction of transitions of the north atlantic eddy driven jet the consistency of ensemble forecasts from three global medium range prediction systems with the observed transition behaviour of a three cluster model of the north atlantic eddy driven jet is examined the three clusters consist of a mid jet cluster taken to represent an undisturbed jet and south and north jet clusters representing southward and northward shifts of the jet the ensemble forecasts span a period of three extended winters october february from october 2007 february 2010 the mean probabilities of transitions between the clusters calculated from the ensemble forecasts are compared with those calculated from a 23 extended winter climatology taken from the european centre for medium range weather forecasts 40 year re analysis era40 dataset no evidence of a drift with increasing lead time of the ensemble forecast transition probabilities towards values inconsistent with the 23 extended winter climatology is found the ensemble forecasts of transition probabilities are found to have positive brier skill at 15 day lead times it is found that for the three extended winter forecast set probabilistic forecasts initialized in the north jet cluster are generally less skilful than those initialized in the other clusters this is consistent with the shorter persistence time scale of the north jet cluster observed in the era40 23 extended winter climatology copyright 2011 royal meteorological society

rigorous 3d change determination in antarctic peninsula glaciers from stereo worldview 2 and archival aerial imagery abstract this paper presents detailed elevation and volume analysis of 16 individual glaciers grouped at four locations spread across the antarctic peninsula ap the study makes use of newly available worldview 2 satellite stereo imagery to exploit the previously untapped value of archival stereo aerial photography high resolution photogrammetric digital elevation models dems are derived to determine three dimensional glacier change over an unprecedented time span of six decades with an unparalleled mean areal coverage of 82 per glacier the use of an in house robust surface matching algorithm ensured rigorous alignment of the dems to overcome inherent problems associated with processing archival photography most notably the identification and correction of scale error in some datasets the analysis provides insight into one of the most challenging and data scarce areas on the planet by expanding the spatial extent north of the ap to include previously un studied glaciers located in the south shetland islands 81 of glaciers studied showed considerable loss of volume over the period of record the mean annual mass loss for all glaciers yielded 0 24 0 08 m w e per year with a maximum mass loss of up to 62 m w e and frontal retreat exceeding 2 2 km for stadium glacier located furthest north on elephant island observed volumetric loss was broadly though not always correlated with frontal retreat the combined mass balance of all 16 glaciers yielded 1 862 0 006 gt which corresponds to 0 005 mm sea level equivalent sle over the 57 year observation period

correlation in mosaic environments a useful theoretical model for studying some aspects of stratigraphical correlation is that of deposition in mosaic environments the model is readily implemented using computer simulations based on the voronoi diagram and produces lithosome geometries that are broadly comparable to those commonly seen in the field and on seismic sections this model is restricted here to two phase mosaics e g sand shale and the lateral persistence of either phase can readily be determined from the computer simulations this leads directly to measures of the lateral traceability of units of either phase in discontinuous surface outcrop and of reflector persistence in the subsurface because these measures are ultimately scaled in terms of the inherent length scale of the mosaic they can be simply applied to real surface and subsurface data

the morphology structural evolution and significance of push moraines abstract push moraines glaciotectonic ice marginal moraines have a restricted distribution at modern glacier margins and consequently are of potential value in reconstructing pleistocene ice sheets providing data both on former glaciodynamics and on the palaeoenvironment of the glacial foreland to the wider earth science community push moraines are of interest as analogues for thin skin tectonics within orogenic belts this paper reviews the morphology structural geology formation and significance of push moraines the morphological and structural characteristics of small seasonal push moraines through to large multi crested examples produced by sustained glacier advances are reported before the primary controls on push moraine formation are examined these controls include the nature of the applied glacial stress field the presence and properties of decollement horizons and the shear strength and rheology of the glacial foreland a conceptual model of push moraine formation is introduced in which the range of observed morphological and structural forms are viewed within a matrix defined by the main variables which control their formation the absence of consensus over which of these variables is of greatest importance currently limits the significance of push moraines in palaeoglaciological research as a consequence this review emphasises the need for future research in order to realise the true potential of push moraine in the reconstruction of pleistocene environments

late pleistocene glacial events in the central apennines italy the study of glacial evidence in the gran sasso massif of the central apennines italy has allowed the last maximum advance and the subsequent stadial phases to be dated and the mean annual temperature and quantity of precipitation in the form of snow to be assessed for a number of periods the glaciers probably reached their maximum extension campo imperatore stade ca 22 60014c yr b p and started to retreat ca 21 000 yr b p leaving behind three recessional moraines after a first interstade fornaca interstade the fontari stade appears to have taken place shortly after 16 000 yr ago ca 15 000 yr ago the glacier started retreating leaving behind four more recessional moraines an interstade venacquaro interstade preceded the mount aquila stade datable at ca 11 000 yr b p a strong correlation is evident between the glacial phases on land and the isotopic variations in cores from the tyrrhenian sea

compilation of a glacier inventory for the western himalayas from satellite data methods challenges and results abstract due to their sensitive reaction to changes in climatic conditions glaciers have been selected as an essential climate variable ecv although a large amount of ice is located in the himalayas this region is yet only sparsely represented in global glacier databases accordingly a sound and comprehensive change assessment or determination of water resources was not yet possible in this study we present a new glacier inventory for the western himalayas compiled from landsat etm scenes acquired between 2000 and 2002 coherence images from alos palsar image pairs the srtm digital elevation model dem and the aster global dem gdem several specific challenges for glacier mapping were found in this region and addressed they are related to debris cover orographic clouds locally variable snow conditions and creeping permafrost features in cold dry regions additional to seven topographic parameters that are obtained from the aster gdem for each glacier we also determined the relative amount of debris cover on the glacier surface the inventory contains 11 400 glaciers larger than 0 02 km2 which cover a total area of 9 310 km2 analysis of the inventory data revealed characteristic patterns of mean glacier elevation and relative debris cover amounts that might be related to the governing climatic conditions the full dataset will be freely available in the glims glacier database to foster further analyses and modeling of the glaciers in this region

responses to climatic changes since the little ice age on maladeta glacier central pyrenees abstract the evolution of maladeta glacier maladeta massif central spanish pyrenees since the little ice age maximum is analyzed in this work the extent of the glacier was mapped into 10 stages using morainic deposits and graphic documents climatic data temperature and precipitation were reconstructed by using dendroclimatic techniques complemented by recent instrumental records the results thus obtained confirm the control of the above mentioned climatic factors particularly annual temperature and winter precipitation in the evolution of maladeta glacier which has receded from an extent of 152 3 ha in 1820 1830 to 54 5 ha in 2000 a 35 7 reduction in size the rate of ice wastage has varied during that period defining several phases of glacial stabilization 1820 1830 to 1857 1914 1920 to 1934 1935 1957 to 1981 moderated glacial depletion 1901 1904 to 1914 1920 1934 1935 to 1957 and marked glacial depletion 1857 to 1901 1904 1981 to 2000 the evolution of maladeta glacier is also in keeping with trends observed from other alpine mediterranean glaciers which have experienced a consistent rise in their equilibrium line altitudes during the 19th and 20th centuries as well as associated and prolonged periods of negative mass balance

the life cycle of the north atlantic storm track abstractthe north atlantic eddy driven jet exhibits latitudinal variability with evidence of three preferred latitudinal locations south middle and north here the authors examine the drivers of this variability and the variability of the associated storm track the authors investigate the changes in the storm track characteristics for the three jet locations and propose a mechanism by which enhanced storm track activity as measured by upstream heat flux is responsible for cyclical downstream latitudinal shifts in the jet this mechanism is based on a nonlinear oscillator relationship between the enhanced meridional temperature gradient and thus baroclinicity and the meridional high frequency periods of shorter than 10 days eddy heat flux such oscillations in baroclinicity and heat flux induce variability in eddy anisotropy which is associated with the changes in the dominant type of wave breaking and a different latitudinal deflection of the jet the authors results suggest that high heat flu

present and future states of himalaya and karakoram glaciers a complete glacier inventory of the himalaya and karakoram h k has been created by merging records from the chinese glacier inventory several regional inventories produced by the international centre for integrated mountain development kathmandu nepal and partial inventories from the geological survey of india the only remaining gap the indian part of kashmir has been filled by a reconnaissance inventory based on soviet military maps at 1 200 000 scale representing the late 1970s it contains records for 3526 glaciers covering 9584 km 2 the new h k inventory contains records and outlines for 20 812 glaciers covering 43 178 km 2 the extent of ice in the karakoram is slightly less than in the himalaya but the karakoram glaciers are on average twice as thick 160 m as against 80 m a glacier by glacier analysis relying on estimates of mass balance for the entire mountain range and on an extension of the often used volume area scaling relation suggests that up to about one fifth of the glaciers present in 1985 may have disappeared already if mass loss were to remain constant at the average rate for 1975 2008 from 3000 to 13 000 more glaciers might disappear by 2035 if mass loss were to continue to accelerate as inferred for 1985 2008 only a few thousand to a few hundred glaciers might remain in 2035 total area and total mass would each decrease by about one half constant rate assumption or three quarters constant trend assumption these projections which are uncertain and neglect some possibly important mitigating controls such as variable extents of debris cover and the feedback due to retreat to higher elevations demonstrate the need for more complete analyses to inform public perceptions of and policy decisions relating to the health of h k glaciers

recession of the southern part of barnes ice cap baffin island canada between 1961 and 1993 determined from digital mapping of landsat tm changes along the margin of the southern half of the 5900 km 2 barnes ice cap have been assessed using 1993 landsat tm imagery in comparison with digitized 1 50 000 nts maps based on 1961 photogrammetry the average recession over the 183 km long southern perimeter was found to be at least 4 m a 1 with no significant difference between the southeast and southwest sectors viewed in conjunction with the sustained retreat previously reported for the northwest margin these results indicate that a general reduction in the size of barnes ice cap is occurring the present retreat phase began under a regional climate warming in the late 19th to early 20th century period and continues while the record of the ablation season temperature since the midcentury has not shown any significant trend

holocene glaciers in the mongolian altai an example from the turgen kharkhiraa mountains abstract knowledge about the dynamics of modern glaciers is relevant for evaluating climatic change however there is very little and conflicting information about the extent of modern glaciers in northwestern mongolia thus the aim of this paper is to present detailed data about the extent of modern glaciers in the turgen kharkhiraa mountains in the northwestern part of the mongolian altai and to distinguish three main phases of ice extent in 1991 in 1948 and back to the holocene glacial epoch including the so called little ice age lia a worldwide cooling period beginning in the 16th century and lasting until the end of the 19th century grove 1988 based on field work topographic maps and aerial photographs of this region the investigations have shown glacier retreat in 1991 since 1948 as compared to holocene glaciations including the so called little ice age period using the toe to summit altitude tsam method the overall modern snowline can be calculated at about 3537 3559 m asl the area of present glaciers can be calculated to be 33 8 km 2 for the turgen mountains and 39 5 km 2 for the kharkhiraa mountains this is more than 25 of the glaciated area of mongolia the lia snowline was about 80 m lower 3461 3480 m asl whereby the glaciated areas during the lia was 76 8 km 2 and 80 8 km 2 in the two mountain systems respectively in conclusion there has been a remarkable glacier retreat from this holocene and little ice age compared to the glaciation in 1948 and 1991 this glacier retreat coincides with an increase in the snowlines

recommendations for the compilation of glacier inventory data from digital sources modern geoinformatic techniques allow the automated creation of detailed glacier inventory data from glacier outlines and digital terrain models dtms once glacier entities are defined and an appropriate dtm is available several methods exist to derive the inventory data e g minimum maximum and mean elevation mean slope and aspect for each glacier from digital intersection of both datasets compared to the former manual methods the new grid based statistical calculations are very fast and reproducible the major aim of this contribution is to help in standardizing the related calculations to enhance the integrity of the global land ice monitoring from space glims database the recommendations were prepared by a working group and also contribute to the european space agency project globglacier the document follows the former unesco manual for the production of the world glacier inventory published in 1970 identifies the potential pitfalls and describes the differences from the former methods of compilation the online background material for this paper see http www glims org contains example scripts for calculation of each parameter and will be updated when required

separating snow clean and debris covered ice in the upper indus basin hindukush karakoram himalayas using landsat images between 1998 and 2002 summary the hindukush karakoram himalayan mountains contain some of the largest glaciers of the world and supply melt water from perennial snow and glaciers to the upper indus basin uib upstream of tarbela dam which constitutes greater than 80 of the annual flows and caters to the needs of millions of people in the indus basin it is therefore important to study the response of perennial snow and glaciers in the uib under changing climatic conditions using improved hydrological modeling glacier mass balance and observations of glacier responses however the available glacier inventories and datasets only provide total perennial snow and glacier cover areas despite the fact that snow clean ice and debris covered ice have different melt rates and densities this distinction is vital for improved hydrological modeling and mass balance studies this study therefore presents a separated perennial snow and glacier inventory perennial snow cover on steep slopes perennial snow covered ice clean and debris covered ice based on a semi automated method that combines landsat images and surface slope information in a supervised maximum likelihood classification to map distinct glacier zones followed by manual post processing the accuracy of the presented inventory falls well within the accuracy limits of available snow and glacier inventory products for the entire uib estimates of perennial and or seasonal snow on steep slopes snow covered ice clean and debris covered ice zones are 7238 724 5226 522 4695 469 and 2126 212 km2 respectively thus total snow and glacier cover is 19 285 1928 km2 out of which 12 075 1207 km2 is glacier cover excluding steep slope snow cover equilibrium line altitude ela estimates based on the snow line elevation sle in various watersheds range between 4800 and 5500 m while the accumulation area ratio aar ranges between 7 and 80 0 c isotherms during peak ablation months july and august range between 5500 and 6200 m in various watersheds these outputs can be used as input to hydrological models to estimate spatially variable degree day factors for hydrological modeling to separate glacier and snow melt contributions in river flows and to study glacier mass balance and glacier responses to changing climate

global scale modeling of glacier mass balances for water resources assessments glacier mass changes between 1948 and 2006 abstract glaciers play an important role for freshwater resources but in global scale freshwater assessments their impact on river flows has not yet been taken into account as a first step we developed a global glacier model that can be coupled to global land surface and hydrological models with a spatial resolution of 0 5 by 0 5 the glacier model hyoga computes glacier mass balance by a simple degree day approach for 50 m sub grid elevation bands modeling all glaciers within a grid cell as one glacier the model is tuned individually for each grid cell against observed glacier mass balance data hyoga is able to compute glacier mass balances reasonably well even those of summer accumulation type glaciers still model uncertainty is high which is among other reasons due to the uncertainty of global data sets of temperature and precipitation which do not represent well the climatic situation at glacier sites we developed a 59 yr 1948 2006 time series of global glacier mass balance and glacier area by driving hyoga with daily near surface atmospheric data according to our computations most glaciers have lost mass during the study period compared to estimates derived from a rather small number of observed glacier mass balances hyoga computes larger glacier mass losses in asia europe canadian arctic islands and svalbard in accordance with the estimates average annual mass losses have increased strongly after 1990 as compared to the 30 yrs before the sea level equivalent of the melt water from glaciers is 0 76 mm yr water equivalent after 1990 as compared to only 0 34 mm yr water equivalent before we computed an acceleration of glacier mass losses after 1990 for all world regions except south america where the number of gauge observations of precipitation is very small after 1980

fluctuation of glaciers in the southeast russian altai and northwest mongolia mountains since the little ice age maximum the present state and dynamics since the maximum of the lia of the glaciers of southeast russian and north mongolian altai have been studied data were obtained from 15 areas of glaciation the research is based on multiyear in situ observations and analysis of aerial photos of mid 1960s and high resolution space imagery 553 modern glaciers with total area 313 4 km2 have been mapped and put down into catalogues including glaciated areas and glaciers that have not been studied before glacial complexes with united accumulation zone and flat summit glaciers in the center and valley glaciers on the sides are typical for the area of research the firn line level rises from 3200 3300 m in the west to 3600 3700 m in the east this tendency reflects the reduction of nourishment of the glaciers in this direction due to decrease of precipitation the largest valley glaciers exist on the northeastern leeward slopes as a result of two to threefold concentration of snow the last glacial advance in the maximum of lia according to dendrological data finished in the first half of the 19th century from the maximum of the lia the glaciation of the region lost about 51 ela average uplift was 89 m on the background of general trend of glacial retreat there were several periods of stabilization of glacial fronts the most distinct in mid 1960s in the last 50 years there were two warm and dry intervals 1972 1981 and 1992 2008 and three cool and moist intervals prior to 1972 during 1982 1994 and subsequent to 2009 it caused fluctuations of firn line altitude with about 300 m range and abrupt changes of glacial area maximal changes were observed between 1995 and 2008 when areas of the glaciers decreased with average rate 1 2 year determination of retreat of glacial snouts after the lia by geomorphic features is described by vi phase scheme

a more complete version of the world glacier inventory the world glacier inventory wgi was conceived half a century ago as an activity to be completed during the international geophysical year 1957 58 it consisted until very recently of nearly 70 000 glacier records covering slightly less than one quarter of the glacier ice outside the ice sheets a complete wgi must be a compromise if it is to be available and usable soon a more complete version called wgi xf is available and usable now and contains records for just over 131 000 glaciers and nearly half of the global extent of ice the additional glaciers come mainly from the assimilation of existing inventories but also from rescuing inventories that have been lost and from new inventories in canada and the subantarctic in wgi xf the xf stands for extended format flagging the fact that wgi xf conforms to a set of explicit specifications which enhance usefulness by eliminating low level inconsistencies two important features are nominal glaciers and glacier complexes a nominal glacier of which there are about 5000 in wgi xf is one about which little is known other than its existence and approximate location a glacier complex is one or more contiguous glaciers this term embodies the idea which is not new that inventories can be preliminary based upon vector outlines which await subdivision by trained glaciologists many regional studies have found that measurements of changes in single glaciers require accurate work and painstaking quality control wgi xf is not assuredly reliable as a source for such detailed work but there are several other subjects in which less detail would be a price worth paying for more complete coverage incomplete information about the dates of imagery and maps is a hindrance to analysis and the recovery of dates from metadata should have high priority

regional and global volumes of glaciers derived from statistical upscaling of glacier inventory data 1 very few global scale ice volume estimates are available for mountain glaciers and ice caps although such estimates are crucial for any attempts to project their contribution to sea level rise in the future we present a statistical method for deriving regional and global ice volumes from regional glacier area distributions and volume area scaling using glacier area data from 123 000 glaciers from a recently extended world glacier inventory we compute glacier volumes and their sea level equivalent sle for 19 glacierized regions containing all mountain glaciers and ice caps on earth on the basis of total glacierized area of 741 103 68 103 km2 we estimate a total ice volume of 241 103 29 103 km3 corresponding to 0 60 0 07 m sle of which 32 is due to glaciers in greenland and antarctica apart from the ice sheets however our estimate is sensitive to assumptions on volume area scaling coefficients and glacier area distributions in the regions that are poorly inventoried i e antarctica north america greenland and patagonia this emphasizes the need for more volume observations especially of large glaciers and a more complete world glacier inventory in order to reduce uncertainties and to arrive at firmer volume estimates for all mountain glaciers and ice caps

rates of sedimentation and stratigraphical completeness the most obvious result of sedimentation processes is the change in the thickness of accumulated sediment with time whenever the net change over a period of time is positive a record is left of a sedimentation system s existence a stratigraphical section for the stratigrapher the problem that such a section poses is to determine the detailed correspondence of thickness to time1 for the sedimentologist the problem is to infer the nature of the parent sedimentation system and to estimate its parameters a simple stochastic model is used here 1 to illustrate some basic stratigraphical results of clastic sedimentation processes 2 to offer an explanation for the commonly cited systematic decrease of mean sedimentation rate with increasing time span and 3 to assess the concept of stratigraphical completeness it will be assumed that all post depositional non erosional processes such as compaction can be identified and their effects on stratigraphical thickness allowed for

low sea level rise projections from mountain glaciers and icecaps under global warming the mean sea level has been projected to rise in the 21st century as a result of global warming such projections of sea level change depend on estimated future greenhouse emissions and on differing models but model average results from a mid range scenario a1b suggests a 0 387 m rise by 2100 refs 1 2 the largest contributions to sea level rise are estimated to come from thermal expansion 0 288 m and the melting of mountain glaciers and icecaps 0 106 m with smaller inputs from greenland 0 024 m and antarctica 0 074 m here we apply a melt model and a geometric volume model to our lower estimate of ice volume and assess the contribution of glaciers to sea level rise excluding those in greenland and antarctica we provide the first separate assessment of melt contributions from mountain glaciers and icecaps as well as an improved treatment of volume shrinkage we find that icecaps melt more slowly than mountain glaciers whose area declines rapidly in the 21st century making glaciers a limiting source for ice melt using two climate models we project sea level rise due to melting of mountain glaciers and icecaps to be 0 046 and 0 051 m by 2100 about half that of previous projections

on the directional nature of stratigraphic correlation in every correlation exercise the diachroneity of the lithostratigraphic boundaries determines the discrepancy between lithostratigraphic correlation and time correlation here it is shown that diachroneity varies in degree as a simple function of the direction in which correlation is made and hence that stratigraphic correlation must take that direction into account when the direction of correlation is not known a sound strategy for time correlation of lithostratigraphic boundaries is to assume that each is at its most diachronous

revisiting growth and decline of late quaternary mega lakes across the south central tibetan plateau abstract lake basins record critical interactions between the hydrosphere cryosphere and atmosphere their sediments and shoreline landforms archive timing duration and intensity of past climatic variability and environmental impacts over a variety of timescales thousands of lake systems spread across the internally drained tibetan plateau today of which many are only the salty remains of much more expansive paleolakes in the past this study presents new shoreline ages integrated with quantitative digital topographic analysis and regional geomorphic evidence to reconstruct the sizes and extents of late quaternary rift lake systems for the south central tibetan plateau this study presents optically stimulated luminescence osl and the first k feldspar post infrared infrared pirir stimulated luminescence ages for zabuye caka and dawa tso and tests if these lakes were once part of a singular pleistocene mega lake established across four n s rift systems our new results show that two large but separate paleolake systems developed in the latest pleistocene earliest holocene and no lake larger than 6460 km2 has existed since at least 41 ka in the lunggar region early holocene paleolakes expanded up to 7 modern 220 335 km3 with two to four fold asymmetric lake expansion in the west compared to the east findings corroborate earlier investigations implying that dramatic runoff increase and or evapotranspiration reduction prompted rapid earliest holocene lake expansion precipitation variability in combination with permafrost degradation temperature and wind strength governed paleolake moisture balance open system lake behavior and evolving drainage configurations across complex topography explain delayed onsets of lake regression and punctuated lake decline this suggests abrupt holocene climate shifts are not necessarily required for punctuated lake decline lastly unique geomorphological and paleoclimatic similarities between tibetan and east african rift lakes highlight the potential for some tibetan paleolakes to function as natural climate amplifiers over both short and geologic timescales

little ice age glaciers in the balkans low altitude glaciation enabled by cooler temperatures and local topoclimatic controls moraine ridges are present in the highest cirques of the durmitor massif in montenegro and post date the widespread pleistocene moraines of this area lichenometry suggests that at least eight glaciers were present in the 19th century and correlate with the culmination of the little ice age in the european alps cooler temperatures combined with local topoclimatic controls including windblown and avalanching snow as well as shading were crucial for the formation and survival of these glaciers below the regional equilibrium line altitude the resultant regional equilibrium line altitude ela was positioned close to the highest peaks between 2400 and 2500 m with local controls such as avalanche windblown snow and shading depressing the ela in the northern cirques to 2130 2210 m this ela position was very low for this latitude and lower than for most glaciers in the european alps at any time during the holocene and even equivalent to many alpine glaciers during the younger dryas today one glacier still survives in montenegro in a deep northeast facing cirque characterized by the largest combined areas of potential avalanche and windblown snow copyright 2009 john wiley sons ltd

a satellite derived glacier inventory for north asia this study outlines a consistent methodology for identifying glacier surfaces from landsat 5 7 and 8 imagery that is applied to map all mainland north asian glaciers providing the first methodologically consistent and complete glacier inventory for the region 2010 we identify 5065 glaciers covering a planimetric area of 2326 186 km 2 most of which is located in the altai mountain subregion the total glacier count is 15 higher but the total glacier area is 32 11 6 lower than the estimated glacier coverage provided in version 4 0 of the randolph glacier inventory we investigate the distribution of glacier size within north asia and find that the majority of glaciers 82 are smaller than 0 5 km 2 but only account for a third of the total glacier area with the largest 1 60 glaciers 5 km 2 accounting for 28 of the total area we present hypsometric characterizations of north asian glaciers largely substantiating existing findings that glaciers in this region are dominated by cold relatively dry conditions we provide a detailed assessment of errors and determine the uncertainty in our area estimate to be 8 0 with snow cover uncertainty the largest contributing factor based on this assessment the new glacier inventory presented here is more complete and of higher quality than other currently available data sources

recent behaviour of the debeli namet glacier durmitor montenegro a small cirque glacier is present in a north east facing cirque on the mountain of sljeme 2455 m a s l in the durmitor massif montenegro sediment ridges in front of this glacier are interpreted as moraines and can be attributed to recent glacier activity over the past 130 years lichenometry was applied to determine the relative ages of different moraines using aspicilia calcarea agg one set of moraines dates from about 1878 ad whilst another set of inner moraines dates from about 1904 ad the most recent moraines appear to have formed within the last 11 years in front of an active glacier margin copyright 2007 john wiley sons ltd

glacier change on axel heiberg island nunavut canada historical records are valuable for assessing glacier change in the canadian high arctic ommanney s 1969 detailed inventory of axel heiberg island glaciers based on photography from 1958 59 has been revisited converted into digital format and compared to glacier extents mapped from 1999 2000 satellite imagery our results show that the island wide ice coverage decreased by 15 92 km 2 in the 42 year period a loss of 2 if the contributions to ice advance of only three surging glaciers are removed then the island wide ice loss approaches 60 km 2 furthermore it is notable that 90 of ice masses smaller than 0 2 km 2 disappeared entirely during the 42 year study period an observation confirmed by field studies successful predictions from the original inventory are highlighted and the likely mechanisms driving the observed advances and retreats are discussed

sea level rise melting glaciers and ice caps the contribution of glaciers and ice caps to global sea level rise is uncertain they are incompletely counted and the calculation is challenging a new estimate from the best available data suggests a contribution of about 12 cm by 2100

mass balance of glaciers and ice caps consensus estimates for 1961 2004 1 working with comprehensive collections of directly measured data on the annual mass balance of glaciers other than the two ice sheets we combine independent analyses to show that there is broad agreement on the evolution of global mass balance since 1960 mass balance was slightly below zero around 1970 and has been growing more negative since then excluding peripheral ice bodies in greenland and antarctica global average specific balance for 1961 1990 was 219 112 kg m 2 a 1 representing 0 33 0 17 mm sle sea level equivalent a 1 for 2001 2004 the figures are 510 101 kg m 2 a 1 and 0 77 0 15 mm sle a 1 including the smaller greenland and antarctic glaciers global total balance becomes 0 38 0 19 mm sle a 1 for 1961 1990 and 0 98 0 19 mm sle a 1 for 2001 2004 for 1991 2004 the glacier contribution 0 77 0 26 mm sle a 1 is 20 30 of a recent estimate of 3 2 0 4 mm a 1 of total sea level rise for 1993 2005 while our error estimates are not rigorous we believe them to be liberal as far as they go but we also discuss several unquantified biases of which any may prove to be significant

systematic model forecast error in rossby wave structure diabatic processes can alter rossby wave structure consequently errors arising from model processes propagate downstream however the chaotic spread of forecasts from initial condition uncertainty renders it difficult to trace back from root mean square forecast errors to model errors here diagnostics unaffected by phase errors are used enabling investigation of systematic errors in rossby waves in winter season forecasts from three operational centers tropopause sharpness adjacent to ridges decreases with forecast lead time it depends strongly on model resolution even though models are examined on a common grid rossby wave amplitude reduces with lead 5 days consistent with underrepresentation of diabatic modification and transport of air from the lower troposphere into upper tropospheric ridges and with too weak humidity gradients across the tropopause however amplitude also decreases when resolution is decreased further work is necessary to isolate the contribution from errors in the representation of diabatic processes

the link between eddy driven jet variability and weather regimes in the north atlantic european sector this study reconciles two perspectives on wintertime atmospheric variability in the north atlantic european sector the zonal mean framework comprising three preferred locations of the eddy driven jet southern central northern and the weather regime framework comprising four classical north atlantic european regimes atlantic ridge ar zonal zo european scandinavian blocking bl greenland anticyclone ga a k means clustering algorithm is used to characterize the two dimensional variability of the eddy driven jet stream defined by the lower tropospheric zonal wind in the era interim reanalysis the first three clusters capture the central jet and northern jet along with a new mixed jet configuration a fourth cluster is needed to recover the southern jet the mixed cluster represents a split or strongly tilted jet neither of which is well described in the zonal mean framework and has a persistence of about one week similar to the other clusters connections between the preferred jet locations and weather regimes are corroborated southern to ga central to zo and northern to ar in addition the new mixed cluster is found to be linked to european scandinavian blocking whose relation to the eddy driven jet was previously unclear

canada and the world glacier inventory this paper reviews the origins of the world glacier inventory program and canada s participation it tracks the program of the canadian federal government from its initiation to its demise today progress is geared towards the international glims and globglacier programs to which scientists from several canadian universities are making contributions achievements during the past decade towards providing data on canada s glacierized areas in the arctic and in western canada are documented

geomorphic influence on small glacier response to post little ice age climate warming julian alps europe the evolution of glaciers and ice patches as well as the equilibrium line altitude ela since the little ice age lia maximum were investigated in the julian alps south eastern european alps including ice masses that were previously unreported twenty three permanent firn and ice bodies have been recognized in the 1853 km2 of this alpine sector covering a total area in 2012 of 0 385 km2 about one fifth of the area covered during the lia 2 350 km2 these features were classified as very small glaciers glacierets or ice patches with major contribution to the mass balance from avalanches and wind blown snow localized snow accumulation is also enhanced in the area due to the irregular karst topography the ice masses in the region are at the lowest elevations of any glaciers in the alpine chain and are characterized by low dynamics the elas of the two major lia glaciers canin and triglav have been established at 2275 10 m and 2486 10 m respectively by considering the reconstructed area and digital elevation model dem and using an accumulation area ratio aar of 0 44 0 07 typical of small cirque glaciers changes in the ela and glaciers extension indicate a decoupling from climate this is most evident in the smallest avalanche dominated ice bodies which are currently controlled mainly by precipitation the damming effect of moraine ridges and pronival ramparts at the snout of small ice bodies in the julian alps represents a further geomorphological control on the evolution of such ice masses which seem to be resilient to recent climate warming instead of rapidly disappearing as should be expected copyright 2016 john wiley sons ltd

a new glacier inventory on southern baffin island canada from aster data i applied methods challenges and solutions the quantitative assessment of glacier changes as well as improved modeling of climatechange impacts on glaciers requires digital vector outlines of individual glacier entities unfortunately such a glacier inventory is still lacking in many remote but extensively glacierized regions such as the canadian arctic multispectral satellite data in combination with digital elevation models dems are particularly useful for creating detailed glacier inventory data including topographic information for each entity in this study we extracted glacier outlines and a dem using two adjacent terra aster scenes acquired in august 2000 for a remote region on southern baffin island canada additionally little ice age lia extents were digitized from trimlines and moraines visible on the aster scenes and landsat mss and tm scenes from the years 1975 and 1990 were used to assess changes in glacier length and area because automated delineation of glaciers is based on a band in the shortwave infrared we have developed a new semi automated glacier mapping approach for the mss sensor wrongly classified debris covered glaciers water bodies and attached snowfields were corrected manually for both aster and mss glacier drainage divides were manually digitized by combining visual interpretation with dem information in this first paper we describe the applied methods for glacier mapping and the glaciological challenges encountered e g data voids snow cover ice caps tributaries while the second paper reports the data analyses and the derived changes

middle to late holocene glacial variations periglacial processes and alluvial sedimentation on the higher apennine massifs italy the major climatic variations that have affected the summit slopes of the higher apennine massifs in the last 6000 yr are shown in alternating layers of organic matter rich soils and alluvial glacial and periglacial sediments the burial of the soils triggered by environmental climatic variations took place in several phases for the last 3000 yr chronological correlations can be drawn between phases of glacial advance scree and alluvial sedimentation and development of periglacial features during some periods the slopes were covered by vegetation up to 2700 m and beyond while in other phases the same slopes were subject to glacial advances and periglacial processes and alluvial sediments were deposited on the high plateaus around 5740 5590 1560 1370 and 1300 970 cal yr b p organic matter rich soils formed on slopes currently subject to periglacial and glacial processes the mean annual temperature must therefore have been higher than at present furthermore on the basis of the variations in the elevation of the lower limit reached by gelifraction it can be concluded that the oscillations in the minimum winter temperatures could have ranged between 3 0 c lower ca 790 150 cal yr b p and 1 2 c higher ca 5740 5590 cal yr b p than present minimum winter temperatures during the last 3000 yr the cold phases recorded by the calderone glacier advance in the apennines essentially match basically the phases of glacial advance in the alps

the randolph glacier inventory a globally complete inventory of glaciers the randolph glacier inventory rgi is a globally complete collection of digital outlines of glaciers excluding the ice sheets developed to meet the needs of the fifth assessment of the intergovernmental panel on climate change for estimates of past and future mass balance the rgi was created with limited resources in a short period priority was given to completeness of coverage but a limited uniform set of attributes is attached to each of the 198 000 glaciers in its latest version 3 2 satellite imagery from 1999 2010 provided most of the outlines their total extent is estimated as 726 800 34 000 km 2 the uncertainty about 5 is derived from careful single glacier and basin scale uncertainty estimates and comparisons with inventories that were not sources for the rgi the main contributors to uncertainty are probably misinterpretation of seasonal snow cover and debris cover these errors appear not to be normally distributed and quantifying them reliably is an unsolved problem combined with digital elevation models the rgi glacier outlines yield hypsometries that can be com bined with atmospheric data or model outputs for analysis of the impacts of climatic change on glaciers the rgi has already proved its value in the generation of significantly improved aggregate estimates of glacier mass changes and total volume and thus actual and potential contributions to sea level rise

the shape propagation and mean flow interaction of large scale weather systems abstract for a zonal average operator the eliassen palm flux provides a diagnostic of both eddy behavior and the feedback of the eddies onto the mean flow this paper addresses the diagnosis problem for other averaging operators and in particular for time averaging which has proved in recent years such a powerful means of viewing the three dimensional tropospheric flow the horizontal velocity correlation tensor gives a measure of the characteristic horizontal eddy shape at a point it also implies the direction of the group velocity relative to the mean flow in cases where such a concept is valid however the major emphasis here is on the mean flow feedback of eddies in this respect the eddy vorticity flux is determined by derivatives of the components of the anisotropic part of the tensor making a reasonable approximation allows the eddy vorticity flux convergence to be written in terms of e v 2 u 2 u v a simple interpretation of the mean flow feedback of eddies is then possible a sligh

using glacier area ratio to quantify effects of melt water on runoff summary twenty four headwater catchments with varying glacier area ratios gars in the eastern and central tian shan mountains were simulated by the glacier enhanced soil and water assessment tool swat model from 1961 to 2007 the mean catchment gar ranges between 0 7 and 44 8 with a mean of 8 6 through synthetic analysis of the glacio hydrological processes simulation results of the catchments it was found that the gar is an effective index that can be used to interpret quantitatively the varying influences of glaciers on runoff across catchments among the twenty four catchments the ratio of glacier melt contribution rgmc to runoff varies between 3 5 and 67 5 with a mean of 24 0 the ratio of ice melt contribution rimc between 1 4 and 35 8 with a mean of 10 5 the ratio of ice melt in glacier melt between 33 4 and 59 1 with a mean of 43 4 the runoff coefficient rc between 0 24 and 0 90 with a mean of 0 52 and the coefficient of variation cv of runoff between 0 10 and 0 29 with a mean of 0 18 based on synthetic analysis it was found that 1 power functions fit the relations between rgmc rimc rc and cv and gar with high certainty 2 the cv decreases with increasing gar while others increase and 3 these power functions change sensitively with gar when gar is less than 10 implicating that a small change in gar may cause remarkable changes in rgmc rimc rc and cv in the less glacierized catchments

time scale for adjustment of glaciers to changes in mass balance the length of time tm over which a glacier responds to a prior change in climate is investigated with reference to the linearized theory of kinematic waves and to results from numerical models we show the following tm may in general be estimated by a volume time scale describing the time required for a step change in mass balance to supply the volume difference between the initial and final steady states the factor f in the classical estimate of m l u where i is glacier length and u is terminus velocity has a simple geometrical interpretation ft is the ratio of thickness change averaged over the full length i to the change at the terminus although both u and f relate to dynamic processes local to the terminus zone the ratio f u and therefore tm are insensitive to details of the terminus dynamics in contrast to conclusions derived from some simplified kinematic wave models a more robust estimate of tm independent of terminus dynamics is given by tm h b where h is a thickness scale for the glacier and b is the mass balance rate negative at the terminus we suggest that tm for mountain glaciers can be substantially less than the 1o2 103 years commonly considered to be theoretically expected

punctuated aggradational cycles a general hypothesis of episodic stratigraphic accumulation according to the hypothesis of punctuated aggradational cycles presented here the stratigraphic record consists of small scale 1 5 m thick shallowing upward cycles pacs separated by surfaces marked by abrupt change to deeper facies this motif pervasive in time and environment is produced by relatively long periods tens of thousands of years of base level stability punctuated by geologically instantaneous relative base level rises of at least basin wide extent as basin wide lithologic time stratigraphic units pacs are fundamental to all aspects of stratigraphic analysis including correlation paleoenvironmental interpretation and paleogeographic reconstruction of several possible allogenic mechanisms for a pervasively cyclic stratigraphic record glacial eustasy driven by orbital perturbations is preferred the pac hypothesis is presented as a comprehensive model to be tested and modified by examination of the stratigraphic record from an episodic perspective

sensitivities of the equilibrium line altitude to temperature and precipitation changes along the andes abstract equilibrium line altitudes elas of alpine glaciers are sensitive indicators of climate change and have been commonly used to reconstruct paleoclimates at different temporal and spatial scales however accurate interpretations of ela fluctuations rely on a quantitative understanding of the sensitivity of elas to changes in climate we applied a full surface energy and mass balance model to quantify ela sensitivity to temperature and precipitation changes across the range of climate conditions found in the andes model results show that ela response has a strong spatial variability across the glaciated regions of south america this spatial variability correlates with the distribution of the present day mean climate conditions observed along the andes we find that elas respond linearly to changes in temperature with the magnitude of the response being prescribed by the local lapse rates ela sensitivities to precipitation changes are nearly linear and are inversely correlated with the emissivity of the atmosphere temperature sensitivities are greatest in the inner tropics precipitation becomes more important in the subtropics and northernmost mid latitudes these results can be considered an important step towards developing a framework for understanding past episodes of glacial fluctuations and ultimately for predicting glacier response to future climate changes