storm time evolution of elf vlf waves observed by demeter satellite in this paper using the data of sun synchronous satellite detection of electro magnetic waves transmitted from earthquake regions demeter we investigated the storm time variations of elf vlf waves during the intense coronal mass ejections cme driven storms from 2005 to 2009 the results show that there is a good correlation between the enhancement of elf vlf waves and the cme events immidately following the enhanced wave activity driven by cmes at the initial phase the wave intensity decreases temporarily at the beginning of storm main phase the strongest waves predominantly occur from the late main phase to early recovery phase the elf waves below 3 khz are significantly intensified during the whole storm time while the high frequency waves above 3 khz seem strengthened predominantly during the late main and early recovery phase the elf waves below 3 khz can exist in a wide l shell range with the intensity peaking at l 3 and 4 high frequency waves at f 9 khz exist mostly outside the plasmapause the stronger elf vlf waves on the dayside can last longer time than those on the nightside

chemical weathering rates of silicate dominated lithological classes and associated liberation rates of phosphorus on the japanese archipelago implications for global scale analysis abstract lithology is an important characteristic of the terrestrial surface whose properties influence chemical weathering rates specifically non silicate minerals may contribute significantly to the weathering derived fluxes from silicate dominated lithological classes the japanese archipelago consists of predominantly silicate dominated lithologies with a high proportion of volcanics however the spatially explicit representation of chemical weathering rates remains difficult for such a large region because many controlling factors on chemical weathering rates are correlated with each other due to the spatial heterogeneity of lithology a multi lithological model approach to estimate spatially explicit chemical weathering rates for unmonitored areas is applied here to achieve this hydrochemical data of 381 catchments are used to train a set of models recognizing the contribution of a variety of proposed factors influencing chemical silicate rock weathering rates csrwr cations plus dissolved silica flux the monitored catchments cover 44 of the japanese archipelago cation chemical weathering rates excluding si are linearly correlated with csrwr and show outliers if basic volcanics or pyroclastic flows are present due to increased silica release rates lithology and runoff are identified as the strongest predictors for chemical weathering rates temperature and gradient of slope are of less relevance for the regional scale prediction while further proposed factors like soil properties or land cover are not identified as major predictors latter findings are partly attributed to geodata quality low variability of parameter values as well as spatial correlations of proposed controlling factors with lithology or runoff the calculated average csrwr of the archipelago is 25 t km 2 a 1 and ranges from 5 9 to 107 t km 2 a 1 in monitored catchments weathering rates per lithological class as a function of runoff can be grouped into three classes a pyroclastic flows showing the highest chemical weathering rates b alluvial deposits mixed sediments and basic to intermediate volcanics with medium rates and c metamorphics siliciclastic sediments acid volcanics acid plutonics and unconsolidated sediments other than alluvial deposits showing the lowest rates the recognition of lithogenic sulfur would add 9 7 to csrwr of considered catchments results suggest that the lithological classes acid volcanics and unconsolidated sediments contribute above average to the sulfur fluxes possible biases of this observation are discussed the contribution of ca fluxes from non silicate calcic minerals named ca excess ca fluxes in addition to silicate ca fluxes is about 10 of the csrwr on average and is attributed by a wide value range the calculated ratio ca excess to total ca fluxes from chemical weathering averages around 62 75 56 83 and 84 for the lithological classes acid plutonics metamorphics siliciclastic sediments mixed sediments and acid volcanics respectively this suggests a major ca contribution from non silicate calcic minerals for these lithological classes phosphorus release from rocks due to chemical weathering is estimated to be between 1 kg p km 2 a 1 and 390 kg p km 2 a 1 the p release patterns in dependence of runoff per lithological class are different from csrwrs due to differences of applied p content in rocks the identified spatial p release patterns suggest that the consideration of dynamic and spatially resolved p release rates by chemical weathering might improve ecosystem studies later findings may be of importance for analysing the influence of p release from rocks on the climate system via ecosystem functioning on geological time scales a first application of the p release model to the global scale suggests an annual release of 1 6 mt p 13 8 kg p km 1 a 1 by chemical weathering of silicate dominated lithological classes excluding carbonate sedimentary rocks

new tree ring dates for recent eruptions of mount st helens abstract distinctive patterns of growth rings in increment cores from old growth douglas fir pseudotsuga menziesii stands identify a d 1800 as a more precise date for the eruption of tephra layer t by mount st helens washington layer t was previously inferred to date to about a d 1802 growth patterns also establish a d 1480 as the date of eruption of the earlier layer wn previously estimated as dating to about a d 1500 the timing of radial tree growth places a small limitation on the seasonal resolution of these new tree ring dates

predicting riverine dissolved silica fluxes to coastal zones from a hyperactive region and analysis of their first order controls silicate weathering and resulting transport of dissolved matter influence the global carbon cycle in two ways first by the uptake of atmospheric soil co2 and second by providing the oceanic ecosystems via the fluvial systems with the nutrient dissolved silica dsi previous work suggests that regions dominated by volcanics are hyperactive or even hot spots concerning dsi mobilization here we present a new approach for predicting dsi fluxes to coastal zones emphasizing first order controlling factors lithology runoff relief land cover and temperature this approach is applied to the japanese archipelago a region characterized by a high percentage of volcanics 29 1 of surface area the presented dsi flux model is based on data of 516 catchments covering approximately 56 7 of the area of the japanese archipelago the spatial distribution of lithology one of the most important first order controls is taken from a new high resolution map of japan results show that the japanese archipelago is a hyperactive region with a dsi yield 6 6 times higher than the world average of 3 3 t sio2 km 2 a 1 but with large regional variations approximately 10 of its area exceeds 10 times the world average dsi yield slope constitutes another important controlling factor on dsi fluxes besides lithology and runoff and can exceed the influence of runoff on dsi yields even though the monitored area on the japanese archipelago stretches from about 31 to 46 n temperature is not identified as a significant first order model variable this may be due to the fact that slope runoff and lithology are correlated with temperature due to regional settings of the archipelago and temperature information is substituted to a certain extent by these factors land cover data also do not improve the prediction model this may partly be attributed to misinterpreted land cover information from satellite images implications of results for earth system and global carbon cycle modeling are discussed

age distribution and stratigraphy of glacier peak tephra in eastern washington and western montana united states tephra layers from williams lake fen wildcat lake and east wenatchee washington and kearns basin lost trail pass sheep mountain bog and marys frog pond montana were analyzed by electron mi

ionospheric response to the initial phase of geomagnetic storms common features 1 ionospheric responses to the initial phases of three geomagnetic storms 2 5 april 2004 7 9 november 2004 and 13 16 december 2006 were compared using both ground based gps total electron content tec data and coupled magnetosphere ionosphere thermosphere cmit model simulations the onset times for these storms all occurred at local daytime in the north american sector this similarity of onset times and other factors resulted in some common features in their ionospheric response these common features include 1 enhanced tec positive response at low and middle latitudes in the daytime 2 depleted tec negative response around the geomagnetic equator in the daytime 3 a north south asymmetry in the positive response as the northern hemispheric response appeared to be more pronounced and 4 negative response at high latitudes as the storms progressed the cmit model captured most of these features analysis of model results showed that storm time enhancements in the daytime eastward electric field were the primary cause of the observed positive storm effects at low and middle latitudes as well as the negative response around the geomagnetic equator in the daytime these eastward electric field enhancements were caused by the penetration of high latitude electric fields to low latitudes during southward interplanetary magnetic field imf periods when imf bz oscillated between southward and northward direction in the initial shock phase of the storms consequently the ionosphere was lifted up at low and middle latitudes to heights where recombination was weak allowing the plasma to exist for a long period resulting in higher densities in addition the cmit model showed that high latitude negative storm responses were related to the enhancements of molecular nitrogen seen in timed global ultraviolet imager observations whereas the negative storm effects around the geomagnetic equator were not associated with thermospheric composition changes they were the result of plasma transport processes

genesis of a holocene soil chronosequence from the southernmost andes mountains tierra del fuego abstract at the southernmost andes mountains the martial cirque glacier has retreated 2 km in distance and 500 m in elevation since the mid holocene this study examines soil properties processes and classification in relation to soil age and elevation soils were sampled at elevations from 430 to 925 m a s l on drifts periodically influenced by volcanic ash that represent five age classes 5 0 to 6 0 kyr bp under deciduous nothofagus pumilio forest 1 3 to 3 2 kyr bp under n pumilio and n antarctica forest and tundra 0 3 to 1 4 kyr bp under tundra 0 3 kyr bp ce under tundra and 0 007 kyr bp ce under scattered lichens and mosses the soils represent a developmental sequence on metapellitic rocks ranging from cryorthents dystrocryepts humicryepts and humicryods in general the soils contain abundant coarse fragments sandy loam textures and high levels of organic c clays have been altered in the soils from chlorite to a hydroxyl interlayered vermiculite and ferrihydrite the most developed soils are very strongly acid al saturated and have illuvial horizons enriched in fulvic acid c and organic bound forms of free fe and al the following properties are highly correlated with soil age pyrophosphate soluble iron fep in the b horizon r2 0 97 color development equivalence in the b horizon r2 0 87 clay content of the b horizon r2 0 68 and fulvic acid c in the b horizon r2 0 65 the results of this study imply that soil formation in magellanic subantarctic forests and tundra is rapid and involves podsolization andisolization and humification as primary soil forming processes

bicarbonate fluxes and co2 consumption by chemical weathering on the japanese archipelago application of a multi lithological model framework abstract prediction of co 2 consumption by chemical weathering is important to understand the global carbon cycle and island arcs are assumed to contribute significantly to the transfer of atmospheric soil co 2 to the oceans previous work established empirical functions for bicarbonate flux and co 2 consumption in dependence of runoff for five to six lithological classes these functions were applied in global studies however it has remained uncertain if improvements can be achieved by considering further factors or by an enhanced lithological classification scheme this study applies a new lithological map of japan with an enhanced lithological classification a hydrochemical data set representing 382 catchments covering 44 4 of the japanese archipelago and a multi lithological model approach to predict bicarbonate fluxes and co 2 consumption by chemical weathering because of significant carbonate contents in sediments different from carbonate sedimentary rocks acid plutonics and metamorphics firstly a bicarbonate flux model approach is established and secondly silicate and carbonate co 2 consumption is estimated based on the geochemical composition of rocks in accordance with previous studies on the catchment scale the most important factors controlling bicarbonate fluxes are lithology and runoff the anion ratio hco 3 so 4 2 cl is identified as the third most important predictor because anion sources and anion composition of river water have a great effect on bicarbonate concentrations and last but not least potential predictors such as gradient of slope temperature and physical erosion explain some part of the observed bicarbonate flux variation these potential predictors have been discussed in literature but quantification of the effects of these factors remains difficult due to their correlation with runoff and lithology however all tested models reproduce a total of observed bicarbonate fluxes within 10 on the regional scale including the simplest model which recognizes only lithology and runoff as predictors model results suggest that bicarbonate flux from the japanese archipelago is about 6 61 t c km 2 a 1 and co 2 consumption by chemical weathering is about 6 05 t c km 2 a 1 91 6 of bicarbonate flux this co 2 consumption rate is 3 2 times above the global average rate the silicate to carbonate co 2 consumption ratio is comparatively high it amounts to 9 9 which is above the global value the latter one being 1 to 1 5 carbonate sedimentary rocks contribute only 1 3 to bicarbonate fluxes due to their low areal proportion 0 2 acid volcanic rocks va show the lowest bicarbonate fluxes on average while basic and intermediate volcanics vb as well as pyroclastics py are in the range of the japanese average value the carbonate weathering contribution to bicarbonate fluxes from mixed sediments siliciclastic sediments metamorphics and acid plutonics is estimated to be 69 2 23 3 63 4 and 24 8 respectively only an average carbonate co 2 consumption per lithological class is calculated because no function based on typical predictors could be established to calculate carbonate weathering contribution to silicate dominated lithological classes this can be attributed to large spatial differences in carbonate content in rocks and to corresponding contributions to bicarbonatefluxes in the following results are compared to bicarbonate flux models of previous studies and identified differences are discussed in conclusion recognition of carbonate abundance in silicate dominated lithological classes including trace calcite is important to calculate silicate carbonate co 2 consumption ratios presented results are relevant for studies modelling co 2 consumption by chemical weathering in context of the global c cycle

analysis of subprotonospheric whistlers observed by demeter a case study 1 subprotonospheric sp whistlers consist of a series of low dispersion components that result from repeated reflections between the base of the ionosphere and altitudes up to 1000 km we have used wave normal angles and plasma characteristics measured by the demeter microsatellite as an input for a three dimensional ray tracing technique for several sp whistlers we have also succeeded in finding the causative lightning located at relatively large distances from the satellite footprint along the geomagnetic field line we show that the reflections and formation of the sp whistlers take place owing to an oblique propagation with respect to the magnetic field in the waveguide formed by a profile of the increasing lower hybrid resonance frequency in the upper ionosphere and the base of the ionosphere we have observed propagation across the magnetic meridian planes we conclude that the individual components of the sp whistler propagate along different raypaths the reflected components enter the ionosphere at relatively large distances from the satellite footprint and experience a spread of wave normal angles during this entry depending on the initial wave normal angle these waves undergo a different number of reflections before reaching the satellite thus arriving with different time delays however the first component observed of a sp whistler is formed by waves entering the ionosphere at relatively small distances from the satellite footprint and at relatively small wave normal angles these waves do not reflect above the satellite but propagate to the opposite hemisphere

expression of andic and spodic properties in tephra influenced soils of northern idaho usa abstract tephra from mount mazama crater lake has strongly influenced genesis and morphology of forest soils in the selkirk mountains of northern idaho characteristics associated with andisols and their intergrades are common in soils throughout the area in addition tephra influenced soils of the higher elevations exhibit properties of spodosols as well this study was initiated to examine development and relative expression of these properties along an elevational transect with its associated bioclimatic gradient this paper presents data from three soils that encompass the range in expression of andic and spodic properties found along this gradient cooler moister soils of the higher elevations have formed under subalpine fir forest and are strongly influenced by volcanic ash as indicated by color naf ph glass content and quantities of oxalate extractable fe al and si additionally podzolization processes have created e bhs horizon sequences in these soils within the last 6800 years the clay fraction of the very strongly acid e horizon is dominated by a well crystallized smectite mineral formation of an e horizon has effectively erased andic characteristics such as accumulation of short range order minerals sroms high naf ph and high p retention soils of the middle elevations have formed under western hemlock forest and also have significant ash influence these soils have properties transitional to those of the higher elevation spodosols and do not exhibit the overprint of podzolization processes eluvial horizons are absent although there has been significant accumulation of metal organic complexes and inorganic sroms in the upper horizons of these andisols soils of the lower elevations have developed under relatively warmer and drier conditions associated with the lower end of the western hemlock forest zone and have comparatively less volcanic ash influence the ash has been extensively mixed with coarse textured glacial drift and as a result these lower elevation soils lack the morphological or chemical properties associated with spodosol development but do exhibit weak andic characteristics

carbonate versus silicate weathering in the raikhot watershed within the high himalayan crystalline series the major element and sr isotope geochemistry of surface waters bedrock and river sands was investigated in the raikhot watershed within the high himalayan crystalline series hhcs in northern pakistan mass balance calculations of mineral weathering contributions to the dissolved flux of ions from the watershed indicate that 82 of the hco 3 flux is derived from the weathering of carbonate minerals and only 18 is derived from silicate weathering even though the bedrock is predominantly quartzofeldspathic gneiss and granite with only 1 carbonate in the watershed this study demonstrates the importance of trace amounts of bedrock carbonate in controlling the water chemistry of glacial watersheds we suggest that the flux of sr with a high 87 sr 86 sr ratio in the major himalayan rivers may be derived in large part from weathering of trace amounts of calcite within the largely silicate hhcs models that use the flux of radiogenic sr from the himalayas as a proxy for silicate weathering rates may therefore overestimate the amount of co 2 consumption due to silicate weathering in the himalaya

combined use of relative and absolute dating techniques for detecting signals of alpine landscape evolution during the late pleistocene and early holocene article i nfo a combination of three relative and two absolute numerical dating techniques applied on nine soil profiles in an alpine environment located in val di rabbi trentino northern italy was used to improve the investigation methodology of alpine sites in response to climate change and to reconstruct the chronology of late pleistocene and early holocene landscape evolution the degree of podzolisation clay mineral evolution and the element mass balances of each site were investigated furthermore the stable fraction of the soil organic matter som was extracted with 10 h2o2 and 14 c dated the age of the organic residues was compared with the age of charcoal fragments found in one of the studied soils and with the age of rock boulders obtained by surface exposure dating sed with cosmogenic 10 be numerical dating and weathering characteristics of the soils showed a fairly good agreement and enabled a relative and absolute differentiation of landscape elements the combination of 14 c dating of som and sed indicated that deglaciation processes in val di rabbi were already far advanced by around 14000 cal bp and that glacier oscillations affected the highest part of the region until about 9000 cal bp the development of clay minerals is time dependent and reflects weathering intensity we found a close link between secondary clay minerals like smectite or vermiculite and soil age as obtained by the dating of the organic residues after the h2o2 treatment calculated element mass balances strongly correlated with the ages derived from 14 c measurements old soils have lost a major part of base cations up to 75 compared to the parent material fe and al which indicates a continuous high weathering intensity results of the chemical and mineralogical analyses were in good agreement with numerical dating techniques showing the dynamics of an alpine landscape within a relatively small area the combination of relative and absolute dating techniques is a promising tool for the reconstruction of landscape history in high elevation alpine areas on siliceous substrates

dayside ionospheric response to the intense interplanetary shocks solar wind discontinuities observations from the digisonde global ionospheric radio observatory 1 the digisonde global ionospheric radio observatory giro has recorded strong ionospheric responses to two powerful interplanetary shock passages on 7 november 7 2004 and 21 january 2005 both events provide excellent opportunities to study geospace response processes to strong interplanetary forward shocks in great detail the angle between the normal of the 7 november 2004 shock front and the sun earth line was 3 0 degrees indicating that the shock hit the equatorial magnetosphere at 1200 lt local noon the subsequent dayside shock induced ionospheric phenomena were found to have marked longitudinal and latitudinal distributions comparative studies of the intense interplanetary shocks including the sheath associated with northward and southward interplanetary magnetic fields imf revealed their different geospace effects on the dayside ionospheric region the equatorial ionosphere responds to the interplanetary shock rather quickly and if the shock is associated with southward imf the plasma electrons in the equatorial ionosphere are rapidly uplifted during the 7 november 2004 event the averaged uplift velocity was close to 67 m s and the ionospheric total electron content tec increased from the original 16 tec units tecu to 38 tecu 1 tecu 1016 m 2 which may be due to the shock effect when the interplanetary shock including the magnetosheath is associated with northward imf the plasma in the equatorial ionosphere moves downward causing a sudden drop in the total electron content during the 21 january 2005 event the averaged downward velocity was 120 m s and the tec dropped from 75 tecu to 22 tecu at the time of maximum solar wind dynamic pressure and then recovered to 68 tecu in about 2 h after the shock passage the middle and high latitude ionospheric tec enhancements may be due to particle ion and electron precipitation ionization losses caused by the strong impacts of the interplanetary shocks

holocene vegetation history and fire regimes of pseudotsuga menziesii forests in the gulf islands national park reserve southwestern british columbia canada article i nfo pollen analysis of a 9 03 m long lake sediment core from pender island on the south coast of british columbia was used to reconstruct the island s vegetation history over the last 10 000 years the early holocene was characterized by open mixed woodlands with abundant pseudotsuga menziesii and a diverse understory in cluding salix and rosaceae shrubs and pteridium aquilinum ferns the establishment of quercus garryana savanna woodland with p menziesii and acer macrophyllum followed deposition of the mazama tephra until 5500 cal yr bp when these communities gave way to modern mixed p menziesii forest charcoal anal yses of the uppermost sediments revealed low charcoal accumulation over the last 1300 years with a mean fire return interval mfri of 88 years fires were more frequent mfri 50 yr during the medieval climate anomaly mca with warm dry conditions facilitating a higher fire frequency than during the little ice age when fires were infrequent given the projected warming for the next 50 100 years land managers considering the reintroduction of fire to the gulf islands national park reserve may want to consider using the mfri of the mca as a baseline reference in prescribed burning strategies

dayside midlatitude ionospheric response to storm time electric fields a case study for 7 september 2002 1 with the storm of 7 8 september 2002 as a study case we demonstrate that an ionospheric model driven by a suitable storm time convection electric field can reproduce the f region dayside density enhancements associated with the ionospheric storm positive phase the ionospheric model in this case is the utah state university time dependent ionospheric model tdim the electric field model is the university of michigan s hot electron and ion drift integrator heidi extensive ground truth is available throughout the study period from two independent sources ground based vertical tec and ionosonde stations our simulation results are in good agreement with these observations we address the question of what is the source of the high density plasma that is seen during the positive storm phase and show that in this case a magnetospheric electric field with an eastward component that penetrates to midlatitudes increases local production on the dayside to a degree that is sufficient to account for the storm time density increases that have been observed

mount mazama eruption calendrical age verified and atmospheric impact assessed geochemical identification of mount mazama ash in the greenland ice sheet project 2 gisp2 ice core gives a calendrical age of 7627 150 cal yr b p 5677 150 b c for the eruption thus providing a more accurate early holocene stratigraphic time line than previously available the gisp2 record of volcanically derived sulfate suggests a total stratospheric aerosol loading between 88 and 224 mt spread over an 6 yr period following the eruption of mount mazama taking into account the likelihood of some tropospheric aerosol transport to greenland realistic estimates of the resulting atmospheric optical depth range from 0 6 to 1 5 these values may have produced a temperature depression of 0 6 to 0 7 c at mid to high northern latitudes for 1 3 yr after the eruption these results indicate that the 5677 b c eruption of mount mazama was one of the most climatically significant volcanic events of the holocene in the northern hemisphere we also calculate a maximum stratospheric cl release of 8 1 mt by the eruption which may have led to substantial stratospheric ozone depletion

dynamic plasmapause model based on themis measurements this paper presents a dynamic plasmapause location model established based on 5 years of time history of events and macroscale interactions during substorms themis measurements from 2009 to 2013 in total 5878 plasmapause crossing events are identified sufficiently covering all 24 magnetic local time mlt sectors based on this plasmapause crossing database we investigate the correlations between plasmapause locations with solar wind parameters and geomagnetic indices input parameters for the best fits are obtained for different mlt sectors and finally we choose five input parameters to build a plasmapause location model including 5 min averaged sym h al and au indices as well as hourly averaged ae and kp indices two out of sample comparisons on the evolution of the plasmapause is shown during two magnetic storms demonstrating good agreement between model results and observations two major advantages are achieved by this model first this model provides plasmapause locations at 24 mlt sectors still providing good consistency with observations second this model is able to reproduce dynamic variations of the plasmapause on timescales as short as 5 min

propagation of unducted whistlers from their source lightning a case study 1 we analyze nightside measurements of the demeter spacecraft related to lightning activity at the 707 km altitude of demeter we observe 3 d electric and magnetic field waveforms of fractional hop whistlers at the same time the corresponding atmospherics are recorded by a very low frequency vlf ground based station located in nancay france the source lightning strokes are identified by the meteorage lightning detection network we perform multidimensional analysis of the demeter measurements and obtain detailed information on wave polarization characteristics and propagation directions this allows us for the first time to combine these measurements with ray tracing simulation in order to directly characterize how the radiation penetrates upward through the ionosphere we find that penetration into the ionosphere occurs at nearly vertical wave vector angles as was expected from coupling conditions at distances of 100 900 km from the source lightning the same distance is traveled by the simultaneously observed atmospherics to the vlf ground station the measured dispersion of fractional hop whistlers combined with the ionosonde measurements at the ebro observatory in spain allows us to derive the density profile in the topside ionosphere

effect of basin physical characteristics on solute fluxes in nine alpine subalpine basins colorado usa alpine subalpine basins may exhibit substantial variability in solute fluxes despite many apparent similarities in basin characteristics an evaluation of controls on spatial patterns in solute fluxes may allow development of predictive tools for assessing basin sensitivity to outside perturbations such as climate change or deposition of atmospheric pollutants relationships between basin physical characteristics determined from geographical information system gis tools and solute fluxes and mineral weathering rates were explored for nine alpine subalpine basins in rocky mountain national park colorado using correlation analyses for 1993 and 1994 data stream water nitrate fluxes were correlated positively with basin characteristics associated with the talus environment i e the fractional amounts of steep slopes 30 unvegetated terrain and young debris primarily holocene till in the basins and were correlated negatively with fractional amounts of subalpine meadow terrain correlations with nitrate indicate the importance of the talus environment in promoting nitrate flux and the mitigating effect of areas with established vegetation such as subalpine meadows total mineral weathering rates for the basins ranged from about 300 to 600 mol ha 1 year 1 oligoclase weathering accounted for 30 to 73 of the total mineral weathering flux and was positively correlated with the amount of old debris primarily pleistocene glacial till in the basins although calcite is found in trace amounts in bedrock calcite weathering accounted for up to 44 of the total mineral weathering flux calcite was strongly correlated with steep slope unvegetated terrain and young debris probably because physical weathering in steep gradient areas exposes fresh mineral surfaces that contain calcite for chemical weathering oligoclase and calcite weathering are the dominant sources of alkalinity in the basins however atmospherically deposited acids consume much of the alkalinity generated by weathering of calcite and other minerals in the talus environment published in 2001 by john wiley sons ltd

effects of treethrow microtopography on the characteristics and genesis of spodosols michigan usa summary this study examined the pedogenic effects of pit and mound microtopography formed by tree uprooting in a spodosol haplorthods landscape most soils in treethrow pits were entic haplorthods or spodic upidsamments whereas mound soils usually classified as typic udipsamments suggesting that degree of profile development is undisturbed pit mound given that pit and mound soils are substantially younger than pedons on undisturbed sites rates of pedogenesis are thought to be pit undisturbed mound strong pedogenesis in pits was explained by 1 greater water contents in the upper sola which may facilitate weathering processes 2 thicker o horizons which may lead to increased production of organic acids and 3 greater insulation by thick litter and snow cover which reduces the incidence of soil freezing in winter mound soils may develop impermeable layers of concrete soil frost that impede infiltration of snowmelt waters whereas pit soils remain unfrozen or acquire only a porous granular frost layer thus saturated flow of snowmelt within pits is relatively unrestricted resulting in maximal leaching and profile differentiation

coupling spatial geochemical and lithological information to distinguish silicate and non silicate chemical weathering fluxes lithological maps have been proved to be a useful tool to evaluate regional and global matter fluxes from chemical weathering however lithological classes provide aggregated information of mineralogical geochemical sedimentary or diagenetic properties thus using a limited number of lithological classes introduces by their definition a bias to the analysis of weathering fluxes specifically in the case of multilithological catchments here it is shown that the coupling of geochemical with lithological information may help to better identify the sources of the weathering fluxes using the example of dissolved ca to better distinguish weathering rates of silicate and non silicate minerals

classification and distribution of soils with albic horizons in the usa a preliminary analysis abstract the albic horizon a diagnostic subsurface horizon that is comprised of primary sand and silt particles that are light colored because they lack clay or iron oxide coatings is unique in that it is an eluvial horizon that is defined on the basis of a loss rather than a gain of weathering products over 3000 official soil descriptions were examined in the us natural resources conservation service databases to identify which taxa contain albic horizons albic horizons are present i e more than 8 soil series in seven orders 28 suborders 73 great groups and about 1600 soil series in soil taxonomy orders with albic horizons can be ranked on an area basis alfisols spodosols ultisols mollisols inceptisols entisols aridisols the mean thickness of the albic horizon is 19 cm with the greatest thickness in alorthods 90 cm and the least in xerolls 3 1 humods 4 0 and ustolls 5 6 cm albic horizons may occupy one or two of several positions in the soil profile including i the mineral soil surface ii below an a horizon iii as a buried horizon iv between a variety of diagnostic subsurface horizons in bisequal soils and v in some soils with alternating e and bt lamellae albic horizons separate or are underlain mainly by an argillic or a spodic horizon half 50 of the soils with albic horizons are excessively to well drained many albic horizons have been lost due to cultivation especially in aqualfs udalfs and udults

the pedological heritage of the dolomites northern italy features distribution and evolution of the soils with some implications for land management abstract since 1997 the department of environmental sciences of ca foscari university of venice has undertaken numerous research projects aimed at deepening understanding of pedogenic processes in the dolomites and at highlighting the fundamental contribution that soil science can give to the conservation of natural resources and achieve sustainable management of mountain ecosystems a total of several hundred profiles have been described analyzed and mapped this paper reports the results from the analysis of pedo environmental characters of profiles developed from different parent materials at altitudes between 1300 m and 2900 m and in different conditions of slope exposure and vegetation cover soil forming factors landforms and land surfaces have been interpreted to understand the soil landscape in the mapped areas and to develop a qualitative model of soil geography into the dolomites scenery the application of land evaluation methods in some of the investigated territories that are subjected to intensive tourist fluxes revealed some criticisms collected results also highlighted the high environmental heterogeneity of soils of the dolomites

relative contributions of silicate and carbonate rocks to riverine sr fluxes in the headwaters of the ganges abstract exhumation of the himalayan tibetan orogen is implicated in the marked rise in seawater 87sr 86sr ratios since 40 ma however both silicate and carbonate rocks in the himalaya have elevated 87sr 86sr ratios and there is disagreement as to how much of the 87sr flux is derived from silicate weathering most previous studies have used element ratios from bedrock to constrain the proportions of silicate and carbonate derived sr in river waters here we use arrays of water compositions sampled from the head waters of the ganges in the indian and nepalese himalaya to constrain the end member element ratios the compositions of tributaries draining catchments restricted to a limited range of geological units can be described by two component mixing of silicate and carbonate derived components and lie on a plane in multicomponent composition space key elemental ratios of the carbonate and silicate components are determined by the intersection of the tributary mixing plane with the planes na 0 for carbonate and constant ca na for silicate the fractions of sr derived from silicate and carbonate sources are then calculated by mass balance in sr ca mg na composition space comparison of end member compositions with bedrock implies that secondary calcite deposition may be important in some catchments and that dissolution of low mg trace calcite in silicate rocks may explain discrepancies in sr ca na mg covariation alternatively composition dependent precipitation or incongruent dissolution reactions may rotate mixing trends on cation ratio diagrams however the calculations are not sensitive to transformations of the compositions by incongruent dissolution or precipitation processes provided that the transformed silicate and carbonate component vectors are constrained silicates are calculated to provide 50 of the dissolved sr flux from the head waters of the ganges assuming that discrepancies between ca mg na covariation and the silicate rock compositions arise from addition of trace calcite if the ca mg na mixing plane is rotated by composition dependent secondary calcite deposition this estimate would be increased moreover when 87sr 86sr ratios of the sr inputs are considered silicate sr is responsible for 70 16 1 of the 87sr flux forcing changes in seawater sr isotopic composition since earlier studies predict that silicate weathering generates as little as 20 of the total sr flux in himalayan river systems this study demonstrates that the significance of silicate weathering can be greatly underestimated if the processes that decouple the water cation ratios from those of the source rocks are not properly evaluated

mid holocene glacier peak and mount st helens we tephra layers detected in lake sediments from southern british columbia using high resolution techniques abstract a glacier peak tephra has been found in the mid holocene sediment records of two subalpine lakes frozen lake in the southern coast mountains and mount barr cirque lake in the north cascade mountains of british columbia canada the age depth relationship for each lake suggests an age of 5000 5080 14 c yr b p 5500 5900 cal yr b p for the eruption which closely approximates the estimated age 5100 5500 14 c yr b p of the dusty creek tephra assemblage found near glacier peak the tephra layer which has not been reported previously from distal sites and was not readily visible in the sediments was located using contiguous sampling magnetic susceptibility measurements wet sieving and light microscopy the composition of the glass in pumice fragments was determined by electron microprobe analysis and used to confirm the probable source of this mid holocene tephra layer using the same methods the a d 1481 1482 mount st helens we tephra layer was identified in sediments from dog lake in southeastern british columbia suggesting the plume drifted further north than previously thought this high resolution method for identifying tephra layers in lake sediments which has worldwide application in tephrachronologic paleoenvironmental studies has furthered our knowledge of the timing and airfall distribution of holocene tephras from two important cascade volcanoes

the role of trace minerals in chemical weathering in a high elevation granitic watershed estibere france chemical and mineralogical evidence we investigated chemical weathering in a high elevation granitic environment in three selected watersheds located in the pyrenees france the sites were located on glacial deposits derived from similar hercynian 300 ma granites characterized by the occurrence of zoned plagioclases and trace calcic phases epidote prehnite sphene apatite the surface waters at those sites show high ca na molar ratios 1 which could not be explained by the dissolution of the major plagioclase oligoclase present in the rocks the coupled approach of investigating stream water chemistry and the mineralogy and chemistry of rocks and soils allowed us to explore the role of the weathering of trace calcic minerals in calcium export at the watershed scale the weathering of the trace calcic minerals which represent 1 of the total rock volume are responsible for more than 90 of the calcium export at the sites annual cationic fluxes 23 104 eq km2 yr calculated for the estibere watershed are among the highest reported for high elevation systems draining granitic rocks and 80 of this annual cationic flux can be attributed to the weathering of trace calcic phases calculations based on isotopic values 87sr 86sr go in the same direction except apatite the trace calcic phases appear to be mainly silicates thus the type of chemical weathering observed in the estibere watershed may have an influence on atmospheric co2 consumption by granite weathering however comparison with other watersheds draining granitic environments worldwide and with the two other sites in the pyrenees indicate that the role of trace calcic phases is important in most young environments exposed to chemical weathering e g high elevation catchments on glacial deposits other factors such as the date of glacial retreat the physical denudation rate the hydrological functioning of the watershed and the nature and structure of the soil cover are also important

modelling the chemical weathering fluxes at the watershed scale in the tropics mule hole south india relative contribution of the smectite kaolinite assemblage versus primary minerals we investigate the chemical weathering processes and fluxes in a small experimental watershed sew through a modelling approach the study site is the mule hole sew developed on a gneissic basement located in the climatic gradient of the western ghats south india the model couples a lumped hydrological model simulating the water budget at the watershed scale to the witch model estimating the dissolution precipitation rates of minerals using laboratory kinetic laws forcing functions and parameters of the simulation are defined by the field data the coupled model is calibrated with stream and groundwater compositions through the testing of a large range of smectite solubility and abundance in the soil horizons we found that despite the low abundance of smectite in the dominant soil type of the watershed 4 vol their net dissolution provides 75 of the export of dissolved silica while primary silicate mineral dissolution releases only 15 of this flux overall smectites modelled as montmorillonites are not stable under the present day climatic conditions furthermore the dissolution of trace carbonates in the saprolitic horizon provides 50 of the calcium export at the watershed scale modelling results show the contrasted behavior of the two main soil types of the watershed red soils 88 of the surface are provider of calcium while black soils smectite rich and characterized by a lower drainage consumes calcium through overall carbonate precipitation our model results stress the key role played by minor accessory minerals and by the thermodynamic properties of smectite minerals and by the drainage of the weathering profiles on the weathering budget of a tropical watershed c 2010 elsevier b v all rights reserved

great geomagnetic storm of 9 november 1991 association with a disappearing solar filament 1 we attribute the great geomagnetic storm on 8 10 november 1991 to a large scale eruption that encompassed the disappearance of a 25 solar filament in the southern solar hemisphere the resultant soft x ray arcade spanned 90 of solar longitude the rapid growth of an active region lying at one end of the x ray arcade appears to have triggered the eruption this is the largest geomagnetic storm yet associated with the eruption of a quiescent filament the minimum hourly dst value of 354 nt on 9 november 1991 compares with a minimum dst value of 161 nt for the largest 27 day recurrent coronal hole storm observed from 1972 to 2005 and the minimum 559 nt value observed during the flare associated storm of 14 march 1989 the greatest magnetic storm recorded during the space age overall the november 1991 storm ranks 15th on a list of dst storms from 1905 to 2004 surpassing in intensity such well known storms as 14 july 1982 310 nt and 15 july 2000 317 nt we used the cliver et al and gopalswamy et al empirical models of coronal mass ejection propagation in the solar wind to provide consistency checks on the eruption storm association

solar and interplanetary sources of major geomagnetic storms dst 100 nt during 1996 2005 1 we present the results of an investigation of the sequence of events from the sun to the earth that ultimately led to the 88 major geomagnetic storms defined by minimum dst 100 nt that occurred during 1996 2005 the results are achieved through cooperative efforts that originated at the living with a star lws coordinated dataanalysis workshop cdaw held at george mason university in march 2005 on the basis of careful examination of the complete array of solar and in situ solar wind observations we have identified and characterized for each major geomagnetic storm the overall solar interplanetary solar ip source type the time velocity and angular width of the source coronal mass ejection cme the type and heliographic location of the solar source region the structure of the transient solar wind flow with the storm driving component specified the arrival time of shock disturbance and the start and ending times of the corresponding ip cme icme the storm driving component which possesses a prolonged and enhanced southward magnetic field bs may be an icme the sheath of shocked plasma sh upstream of an icme a corotating interaction region cir or a combination of these structures we classify the solar ip sources into three broad types 1 s type in which the storm is associated with a single icme and a single cme at the sun 2 m type in which the storm is associated with a complex solar wind flow produced by multiple interacting icmes arising from multiple halo cmes launched from the sun in a short period 3 c type in which the storm is associated with a cir formed at the leading edge of a high speed stream originating from a solar coronal hole ch for the 88 major storms the s type m type and c type events number 53 60 24 27 and 11 13 respectively for the 85 events for which the surface source regions could be investigated 54 63 of the storms originated in solar active regions 11 13 in quiet sun regions associated with quiescent filaments or filament channels and 11 13 were associated with coronal holes remarkably nine 11 cme driven events showed no sign of eruptive features on the surface or in the low corona e g no flare no coronal dimming and no loop arcade etc even though all the available solar observations in a suitable time period were carefully examined thus while it is generally true that a major geomagnetic storm is more likely to be driven by a frontside fast halo cme associated with a major flare our study indicates a broad distribution of source properties the implications of the results for space weather forecasting are briefly discussed

relationship between mechanical erosion and atmospheric co2 consumption in the new zealand southern alps to examine the influence of mountain uplift on the long term carbon cycle we used geochemical hydrologic and suspended load data for 12 streams draining the new zealand southern alps to quantify rates of erosion weathering and atmospheric co 2 consumption rapid uplift in the western southern alps elevates mechanical erosion rates by a factor of 13 relative to those on the tectonically stable eastern side 125 10 8 vs 9 4 10 8 g km 2 yr respectively similarly the average chemical weathering rate is 5 times higher on the western compared to eastern side of the mountain range 9 8 10 7 vs 2 0 10 7 g km 2 yr respectively however because the proportion of stream water ca 2 and mg 2 from carbonate weathering increases as the rate of mechanical erosion increases the long term atmospheric co 2 consumption rate on the western side is 2 times higher than that on the eastern side 14 10 4 vs 6 9 10 4 mol km 2 yr respectively and only 1 5 times higher than the global mean value 9 10 4 mol km 2 yr data for major world rivers including himalayan rivers provide a consistent interpretation regarding the relationship between mechanical erosion intensity and the ratio of silicate to carbonate weathering thus we conclude that mountain building increases atmospheric co 2 consumption rates by only a factor of 2 which is much lower than previous estimates

two step development of geomagnetic storms using the dst index more than 1200 geomagnetic storms from weak to intense spanning over three solar cycles have been examined statistically interplanetary magnetic field imf and solar wind data have also been used in the study it is found that for more than 50 of intense magnetic storms the main phase undergoes a two step growth in the ring current that is before the ring current has decayed significantly to the prestorm level anew major particle injection occurs leading to a further development of the ring current and making dst decrease a second time thus intense magnetic storms may often be the result of two closely spaced moderate storms the corresponding signature in the interplanetary medium is the arrival of double structured southward imf at the magnetosphere

summary of pre 1980 tephra fall deposits erupted from mount st helens washington state usa mount st helens has been a prolific source of tephra fall deposits for about 40 000 years these tephra deposits 1 record numerous explosive eruptions 2 form important regional time stratigraphic marker beds and 3 record repeated changes in composition within and between eruptive periods

major geomagnetic storms dst 100 nt generated by corotating interaction regions 1 seventy nine major geomagnetic storms minimum dst 100 nt observed in 1996 to 2004 were the focus of a living with a star coordinated data analysis workshop cdaw in march 2005 in nine cases the storm driver appears to have been purely a corotating interaction region cir without any contribution from coronal mass ejection related material interplanetary coronal mass ejections icmes these storms were generated by structures within cirs located both before and or after the stream interface that included persistently southward magnetic fields for intervals of several hours we compare their geomagnetic effects with those of 159 cirs observed during 1996 2005 the major storms form the extreme tail of a continuous distribution of cir geoeffectiveness which peaks at dst 40 nt but is subject to a prominent seasonal variation of 40 nt which is ordered by the spring and fall equinoxes and the solar wind magnetic field direction toward or away from the sun the o brien and mcpherron 2000 equations which estimate dst by integrating the incident solar wind electric field and incorporating a ring current loss term largely account for the variation in storm size they tend to underestimate the size of the larger cir associated storms by dst 20 nt this suggests that injection into the ring current may be more efficient than expected in such storms four of the nine major storms in 1996 2004 occurred during a period of less than three solar rotations in september to november 2002 also the time of maximum mean imf and solar magnetic field intensity during the current solar cycle the maximum cir storm strength found in our sample of events plus additional 23 probable cir associated dst 100 nt storms in 1972 1995 is dst 161 nt this is consistent with the maximum storm strength dst 180 nt expected from the o brien and mcpherron equations for the typical range of solar wind electric fields associated with cirs this suggests that cirs alone are unlikely to generate geomagnetic storms that exceed these levels

effects of magnetic clouds on the occurrence of geomagnetic storms the first 4 years of wind 1 we investigate geomagnetic activity associated with magnetic clouds as well as some aspects of the clouds magnetic field structure e g magnetic field distributions of the clouds thirty four magnetic cloud events observed by wind over the years 1995 1998 are investigated in this study magnetic clouds are a principal source of strong long lasting interplanetary negative bz fields in solar magnetospheric coordinates and hence are a major source of geomagnetic activity dst 50 nt the region just upstream of a cloud may be a significant source of southward fields instead of or as well as the cloud itself we call this upstream region a sheath if it is bounded by a shock or a pressure pulse and the cloud this study helps to identify the major sources regions of southward bz following shock passages or within the magnetic clouds that are most dominant in the generation of geomagnetic storms it is found that a geomagnetic storm can be induced by 1 a sheath 2 the leading i e front part region of a cloud 3 the trailing part of a cloud and 4 both sheath and cloud regions because of this complexity a storm with a multistep main phase can occur the related occurrence percentages of storms were 17 6 six events 44 1 15 events 5 9 two events and 20 6 seven events and the averaged storm intensities minimum dst were 60 85 92 and 58 nt respectively for the remaining four events 11 8 there were no storms the occurrence timing of storm intensity is highly correlated with the occurrence timing of minimum bz maximum vbs or for a magnetic cloud with the field rotating from southward to northward

field weathering rates of mt st helens tephra the initial stages of chemical weathering in tephra were examined under field conditions in a cool and humid forest ecosystem in the cascade mountains of washington unleached tephra from the 1980 eruption of mt st helens was applied in 5 cm and 15 cm depths to simulate natural tephra deposition leachate solutions from the tephra were then collected and analyzed over a 4 year period concentrations of dissolved elements were combined with the water fluxes to determine elemental fluxes from tephra and to estimate chemical weathering rates solutions leached from the tephra layer indicate incongruent dissolution resulting in formation of a cation depleted silica rich leached layer on glass and mineral surfaces measured weathering rates were 1 3 orders of magnitude less than comparable rates reported in the literature for laboratory dissolution studies but considerably greater than those measured for entire watersheds in field studies dissociation of carbonic acid originating primarily from upward transport of carbon dioxide from the buried soil was the dominant source of protons for weathering reactions weathering rates in the 5 cm treatment were approximately twice those of the 15 cm treatment a greater flux of co2 per unit volume of tephra in the 5 cm treatment is believed to be responsible for the differential weathering rates

lake sediment records of holocene hydroclimate and impacts of the mount mazama eruption north central washington usa abstract multi proxy sediment records from castor lake and scanlon lake north central washington provide a late quaternary perspective on lake catchment hydrologic and ecosystem responses to climate change and the mazama volcanic ashfall event analyses of authigenic carbonate mineral oxygen and carbon isotope values organic carbon and nitrogen content and sedimentological facies were conducted on sediment from castor lake in order to reconstruct lake catchment hydrologic balance the source and abundance of organic matter and variations in lake level sedimentary facies characterization was conducted on the scanlon lake sediment in order to provide supporting evidence for the lake level shifts inferred from the castor lake data marked changes in castor lake proxy values occur from 12 860 to 11 440 calendar years before present yr bp suggesting lake catchment responses to the younger dryas cold reversal including higher lake levels substantial variability in productivity and increased catchment erosion high 18o values at 9630 yr bp indicate that lake levels were lower than at present and that the early holocene was dry sedimentological analyses and 18o data demonstrate that subsequent to the mazama climactic eruption 7600 yr bp a transition to the lowest lake levels of the holocene occurred over several centuries with maximum 18o values at 7290 90 uncertainty range 7020 7500 yr bp and low lake levels persisting until 6190 5960 6410 yr bp lithological changes in the scanlon lake record support these inferences the lowest 18o values of the holocene occur in sediment from 5000 yr bp indicating high lake levels at this time after which a secular trend toward higher 18o values and lower lake levels occurred the prolonged lowstand in the centuries following the mazama eruption suggests that catchment hydrologic characteristics were strongly impacted by the ashfall through effects on soil water retention capacity that similar responses may have occurred in comparable settings within the mazama ashfall zone and that such volcanic events have the potential confound the climate signal in lake sediment records were a similar event to happen in the future catchment hydrology stream river discharge and lake catchment ecosystem dynamics could be affected for centuries

pedogenic processes and soil landscape relationships in north cascades national park washington thunder creek watershed tcw in the northern cascade range washington state provides a complex environment for studying soil formation approximately 15 000 cal yrs b p the cordilleran ice sheet cis overrode the watershed during the last glacial maximum and deposited glacial drift that provides the substratum for soil formation today since then the watershed has been blanketed by tephra from mount mazama glacier peak and mount st helens soils with the gross morphology of spodosols podzols and andisols andosols occur in a complex landscape mosaic in tcw and along the entire washington cascade range the pedologic conundrum addressed in this paper is whether true spodosols are forming in these areas or are they mimics of spodosols based on field morphology and lab analysis soils in tcw are andic subgroups of spodosols and andisols in approximately equal abundance with lesser areas of inceptisols cambisols and some entisols gleysols field morphology and electron microprobe analysis of glass shards shows that the major volume of tephra about 8 cm compacted thickness is predominantly from the eruption of mount mazama 7600 cal yrs bp tephra from this eruption has been mixed into the upper 50 cm of glacial drift and colluvium fallout from other eruptions in tcw had individual compacted thicknesses less than 2 cm we conclude that true spodosols are widespread in tcw they have albic and spodic horizons no pseudo albic horizons of white unweathered tephra layers were found in tcw the cold wet and dominantly conifer covered landscape supports podzolization in tephra rich materials on parts of landforms that have been stable for several thousand years andisols are forming in drier microclimates on gravitationally active landscapes and under herbaceous vegetation inceptisols dominate landforms controlled by water erosion and deposition where tephra has not been preserved in the soil and on active avalanche chutes entisols were found only on active or recent floodplains the distribution of each soil order in tcw corresponds to the preservation of tephra vegetation type and stability of the landform

global scale observations of ionospheric convection during geomagnetic storms 1 the global effects on the ionosphere during periods of intense geomagnetic activity associated with geomagnetic storms are investigated using the super dual auroral radar network superdarn the influence of the main and recovery phases of geomagnetic storms on ionospheric properties such as backscatter occurrence rates velocity distributions and convection patterns are presented the evolution of magnetosphere and ionosphere parameters during the storms did not depend on the origin of the storm e g a coronal mass ejection or a corotating interaction region instead there was a continuum of response to the intensity of the driver for example we found a clear relationship between the most negative value of the southward component of the interplanetary magnetic field imf bz and the most negative value of the sym h index which marks the end of the main phase of a storm this is one of the first superposed epoch studies that analyzes the sunward antisunward line of sight velocity as a function of magnetic local time for geomagnetic storms of various intensities in the noon sector before and during the main phase of the storms the superdarn radars recorded faster antisunward ionospheric plasma drifts together with a significant increase in the number of ionospheric echoes this is consistent with the expected increase in soft particle precipitation in the noon sector and with the reconnection electric field that occurs when the imf bz is strongly negative as is the case during the main phase of storms the superdarn echo occurrence in the noon sector returned to prestorm values early in the recovery phase the overall response was similar in the midnight sector except that the peak echo occurrence for the most intense storms was limited to a narrower time interval centered on the end of the main phase there were reductions in the strong antisunward flows near local midnight observed during the main phase and early in the recovery phase particularly for the intense storm class strong electric fields are applied in the nightside ionosphere during storms and the decameter structures from which superdarn scatter are more easily produced however in regions of energetic auroral precipitation and after a long exposure to strong electric fields there is often a reduction in superdarn echoes due to absorption or changes in radio wave propagation