soil weathering and accumulation rates of oxalate extractable phases derived from alpine chronosequences of up to 1 ma in age abstract in this study we compare newly developed chemical weathering data with previously published data from soils developed along two chronosequences of glacial deposits in the european alps and the rocky mountains wind river range usa by combining these chronosequences we are able to present a comprehensive dataset that represents a time period of 1 ma we describe weathering trends of important elements using a number of weathering indices e g k ca ti ratio the weathering index b of kronberg and nesbitt 1981 and the open mass transport function further we describe the accumulation of al fe si and mn oxyhydroxides including partially organic phases as a function of time and derive the corresponding accumulation rates we calculated pedogenetically formed oxyhydroxides using an approach based on immobile elements our study represents one of only a few studies that describe rates of soil chemical weathering over a period as long as 1 ma results show that rates of chemical weathering clearly decrease along the chronosequences with increasing age of the soils we find weathering rates are nearly four orders of magnitude lower in the 1 ma old soils than in the young soils our results suggest that the older soils may be reaching a steady state for these chemical properties in their present environments a power function best explains the measured time trends of the index b and k ca ti ratios in the soils the best time trend model for pedogenic weakly to poorly crystalline phases and the relative losses gains based on the open system mass transport function were obtained with an exponential decay model function in terms of the soil system the decreases in the accumulation rate of the oxyhydroxides appears to be influenced not only by the factor of time but by climate as well increased precipitation at higher altitudes slows the decrease in weathering rate over time thus our 1 ma chronosequences also become pedogenic gradients since we describe variations in soil properties along biogenic gradients

west wall structuring of equatorial plasma bubbles simulated by three dimensional hirb model plasma density depletions in the equatorial ionosphere or so called equatorial plasma bubbles epbs are generated in the postsunset period and tend to have a very complex spatial structure especially the east west asymmetry of epbs has been reported by various observations using a high resolution bubble hirb model which is a newly developed three dimensional numerical model for the equatorial ionosphere small scale structuring at the west wall of large scale f layer upwelling is clearly reproduced for the first time it is not an eastward neutral wind but a vertical shear of zonal plasma drift velocity at the bottomside of the f region that plays an important role in accelerating the instability growth at the west wall and generating the east west asymmetry of epbs

ionospheric electron density inversion for global navigation satellite systems radio occultation using aided abel inversions the abel inversion of ionospheric electron density profiles with the assumption of spherical symmetry applied for radio occultation soundings could introduce a greater systematic error or sometimes artifacts if the occultation rays trespass regions with larger horizontal gradients in electron density the aided abel inversions have been proposed by considering the asymmetry ratio derived from ionospheric total electron content tec or peak density nmf2 of reconstructed observation maps since knowledge of the horizontal asymmetry in ambient ionospheric density could mitigate the inversion error here we propose a new aided abel inversion using three dimensional time dependent electron density ne based on the climatological maps constructed from previous observations as it has an advantage of providing altitudinal information on the horizontal asymmetry improvement of proposed ne aided abel inversion and comparisons with electron density profiles inverted from the nmf2 and tec aided inversions are studied using observation system simulation experiment osse comparison results show that all three aided abel inversions improve the ionospheric profiling by mitigating the artificial plasma caves and negative electron density in the daytime e region the equatorial ionization anomaly crests in the f region become more distinct the statistical results show that the ne aided abel inversion has less mean and rmse of error percentage above 250 km altitudes and the performances for all aided abel inversions are similar below 250 km altitudes

landscape evolution post lgm surface denudation and soil weathering processes from dickinson park mire wind river range wyoming usa abstract at mid latitudes the transition from the pleistocene to the holocene was characterised by distinct and partially abrupt climatic changes also during the holocene climatic perturbations with sometimes cold dry conditions have occurred how land surfaces and soil development processes in high mountains respond to these climatic oscillations is so far only poorly known we traced the responses of surfaces in the alpine settings of the wind river range wyoming us by using a large mire as natural archive this enabled us to reconstruct environmental conditions and ecosystem changes during the holocene in this montane area although adjacent moraine deposits display 10be exposure ages from the last glacial maximum up to mis16 or even older the accessible sediment deposits covered only the holocene via radiocarbon dating by applying a geoforensic approach and deriving sedimentation rates major climatic signals were detected a higher deposition and consequently erosion rate and thus a higher rate of geomorphic activity was measured for the known cold periods 9 4 10 2 ka bp 4 2 ka bp and 2 5 ka bp during the lia especially rapid aggradation of organic matter organic matter took place here rates of chemical weathering and soil formation seem to have been relatively low until about 5 6 ka bp but have since increased during the late holocene this would fit previous observations of increasing moisture conditions after the mid holocene aridity period in contrast to several other studies no clear signs of major disturbances erosion weathering during the 8 2 ka event could be observed together with the low levels of chemical weathering found here we do not see any evidence that the climate was more humid during this period compared to previous findings more humid conditions seemed to have returned earlier i e about 5 kyr bp in general this landscape displayed a patchy pattern of reaction to environmental changes as all events were not recorded in each mire profile

multisensor profiling of a concentric gravity wave event propagating from the troposphere to the ionosphere in this paper we present near simultaneous observations of a gravity wave gw event in the stratosphere mesosphere and ionosphere over the south central united states and track it from its convective source region in the troposphere to the ionosphere where it appears as a traveling ionospheric disturbance tid on 4 april 2014 concentric gw ring patterns were seen at stratospheric heights in close proximity to a convective storm over north texas in the atmospheric infrared sounder data on board the nasa aqua satellite concentric gws of similar orientation and epicenter were also observed in mesospheric nightglow measurements of the day night band of the visible infrared imaging radiometer suite on the suomi national polar orbiting partnership satellite concentric tids were seen in total electron content data derived from ground based gps receivers distributed throughout the u s these new multisensor observations of tids and atmospheric gws can provide a unique perspective on ionosphere atmosphere coupling

tracking textural mineralogical and geochemical signatures in soils developed from basalt derived materials covered with loess sediments sw poland abstract this study investigates the scale of inheritance of signatures typical of loess and basalt derived substrates in soils having both components present as parent material due to past periglacial processes based on field description particle size distribution mineralogy heavy minerals and clay minerals as well as geochemistry we track the signal of both materials local basalt derived and loess derived estimate the maximum thickness of loess mantles and mixed zones having both loess and basaltic components and note the presence or absence of basal layers without allochtonous additions the results show that geochemistry and heavy minerals are the most reliable proxies for a verification of aeolian silt contributions and to define individual layers in complex soil parent materials soil formation in the studied landscape depends on the type of slope sediments typical fine grained weathering of basalt without input from aeolian silt would promote rather vertic development however in thick loess deposits as well as in thin silt textured materials superimposed on clay loam beds clay illuviation dominates development of argic horizons however results in decreasing permeability promoting water stagnation and enhanced degradation processes in clay rich subsoil instead of luvisols stagnosols and retisols developed in the study regions basaltic block covers mixed with loess host cambic horizons based on our findings it seems that at the edge of thin loess deposits no soils exist that developed exclusively from basaltic parent materials

cryogenesis and soil formation along a bioclimate gradient in arctic north america 1 in arctic tundra cryoturbation resulting from frost heave cracking and other cryogenic processes produces patterned ground such as nonsorted circles stripes nonsorted polygons and earth hummocks we studied cryogenic structures and morphological properties of soils associated with patterned ground features along a bioclimate gradient in arctic alaska and canada from north subzone a to south subzone e most of these soils have strongly developed cryogenic features including warped and broken horizons and organic matter moved into the upper permafrost the expression of cryoturbation generally increases with the gradient southward soil color reflects the lithology of the soil weathering and accumulation of organic matter the organic horizons form around the circles and gleyed matrix with redoximorphic features develop in the lower active layers due to saturation above the permafrost cryostructure development depends more on hydrology controlled by microtopography than position along the gradient the cryostructures form due to freeze thaw cycles and ice lens formation which include granular platy lenticular reticulate suspended ataxitic ice lens and ice wedges on the surface the density of nonsorted circles reached their maximum in subzones c and d however once the vegetation cover was removed the nonsorted pattern grounds reached their optimum stage and become closed packed in subzone e frost heave decreases in the south as the vegetation changes from tussocks to shrub tundra cryogenesis is the controlling factor in patterned ground formation resulting in cryoturbated soil profiles cryostructures and carbon sequestration in arctic tundra soils

on post midnight field aligned irregularities observed with a 30 8 mhz radar at a low latitude comparison withf layer altitude near the geomagnetic equator 1 we investigated the relationship between post midnightf region field aligned irregularities fais andf layer altitude by analyzing data of a 30 8 mhz radar installed 5at kototabang indonesia 0 2 s 100 3 e geomagnetic latitude 10 4 s and an ionosonde installed at chumphon thailand 10 7 n 99 4 e geomagnetic latitude 3 3 n chumphon is located near the geomagnetic equator on approximately the same meridian as kototabang case studies show that the altitude of thef layer rose at chumphon a half hour before the post midnight fais appeared at kototabang the doppler velocity of thee region fais observed simultaneously by the 30 8 mhz radar was downward indicating that thef layer uplift was not caused by the electric field we also investigated seasonal variations of the post midnight fai occurrence and thef layer altitude both the post midnight fais and the uplift of thef layer were frequently seen around midnight between may and august the seasonal variation of the midnightf layer uplift around the geomagnetic equator coincided with that of the post midnight fai occurrence at kototabang these results suggest that the uplift of thef layer would play an important role in the generation of post midnight fais we evaluated the linear growth rate of the rayleigh taylor instability based on the altitude of thef layer observed at chumphon the result shows that the uplift of thef layer can enhance the growth rate because gravity driven eastward electric current increases therefore we interpret that the observed fais were accompanied by plasma bubble the growth rate of which was reinforced by the upliftedf layer

a climatology of f region gravity wave propagation over the middle and upper atmosphere radar by observing the ionospheric f region simultaneously in multiple beams with the middle and upper atmosphere radar we have been able to track the passage of gravity waves and measure their propagation characteristics here we develop a climatology of wave propagation based on the observation of 58 daytime experiments conducted during 1986 1994 the thermosphere seems to be continuously swept by waves detectable by an incoherent scatter radar these waves generally come for hours on end from a consistent or slowly varying direction which can be any direction on a given day statistically the waves show a moderate preference for southward travel with this preference being reduced or shifted to southeastward travel during disturbed times on average the horizontal phase trace speed remains near 240 m s for all periods inspected 40 130 min this speed matches the behavior expected for lossless waves with 150 200 km vertical wavelength we find small variability in this relation for different times of day seasons solar and magnetic conditions and directions of wave travel though waves on disturbed days seem to travel moderately faster on solar minimum mornings

concentric traveling ionosphere disturbances triggered by super typhoon meranti 2016 concentric traveling ionosphere disturbances ctids in total electron content tec triggered by super typhoon meranti on 13 september 2016 are detected using the ground based global navigation satellite system gnss network in taiwan the ctids emanated outwards before the typhoon landfall and lasted for more than 10 hours the characteristics of ctids agree with the gravity wave theory and exhibit spatial and temporal scales in wave periods of 8 30 minutes horizontal wavelengths of 160 200 km and horizontal phase velocities of 106 220 m s we also observe the ctids showing the stationary wave character broad spectra of ctids are excited after the rainbands of typhoon impinged on central mountain range cmr of taiwan the ray tracing technique confirms that the ctids were excited by convective clouds spiral rainbands and the eyewall of typhoon meranti this study provides new evidence of typhoon induced concentric gravity waves in the ionosphere

the transformation of amphibolite facies gneiss to charnockite in southern karnataka and northern tamil nadu india amphibolite facies metamorphic grade gives way southward to the granulite grade in southern karnataka as acid gneisses develop charnockite patches and streaks and basic enclaves develop pyroxenes petrologic investigations in the transitional zone south of mysore have established the following points 1 the transition is prograde amphibole bearing gneisses intimately associated with charnockite at kabbal and several similar localities are not retrogressive after charnockite as proved by patchy obliteration of their foliation by transgressive very coarse grained charnockite high fluorine content of biotite and amphibole in gneisses and high large ion lithophile element contents in gneisses and charnockites these features are in contrast to very low fluorine in retrogressive amphiboles and biotites very low large ion lithophile element contents and zonal bleaching of charnockite in clearly retrogressive areas as at bhavani sagar tamil nadu 2 metamorphic temperatures in the transitional areas were 700 800 c pressures were 5 7 kbar and h2o pressures were 0 1 0 3 times total pressures based on thermodynamic calculations using mineral analyses dense co2 rich fluid inclusions in the kabbal rocks confirm the low h2o pressures at the first appearance of orthopyroxene farther to the south in the nilgiri hills and adjacent granulite massif areas peak metamorphic temperatures were 800 900 c pressures were 7 9 kbar and water pressures were very low so that primary biotites and amphiboles those with high f contents are rare 3 the incipient granulite grade metamorphism of the transitional areas was introduced by a wave of anatexis and k metasomatism this process was arrested by drying out under heavy co2 influx charnockites so formed are hybrids of anatectic granite and metabasite of metabasite and immediately adjacent gneiss or are virtually isochemical with pre existing gneiss despite gross recrystallization to granulite mineralogy these features show that partial melting and metasomatism are attendant rather than causative in charnockite development copious co2 from a deep crustal or mantle source pushed ahead of it a wave of more aqueous solutions which promoted anatexis granulite metamorphism of both neosome and paleosome followed the process is very similar to that deduced for the madras granulites by weaver 1980 the massif charnockites for the most part extremely depleted in lithophile minor elements show many evidences of having gone through the same process

large scale longitudinal variation in ionospheric height and equatorial spread f occurrences observed by ionosondes 1 variations in ionospheric height associated with the prereversal enhancement pre at two equatorial ionosonde stations separated by 6 34 in longitude were studied for the first time the stations used were in chumphon 10 7 n 99 4 e 3 3 mag lat thailand and bac lieu 9 3 n 105 7 e 1 6 mag lat vietnam variations in the virtual height of the bottomside of the f region h f at 2 5 mhz observed at these two stations were analyzed for a period in march and april 2006 when the equatorial spread f esf was not observed h f variations at the two stations were very similar with a local time shift corresponding to the longitude separation however when esf was observed they were often significantly different our results show that h f enhancement which could be interpreted as being due to the eastward electric field enhancement is quite localized in longitude when esf occurs

first observations of large scale wave structure and equatorial spread f using certo radio beacon on the c nofs satellite 1 first observations of large scale wave structure lsws and the subsequent development of equatorial spread f esf using total electron content tec derived from the ground based reception of beacon signals from the certo coherent electromagnetic radio tomography radio beacon on board c nofs communications navigation outage forecasting system satellite are presented selected examples of tec variations using measurements made during january 2009 from bac lieu vietnam 9 2 n 105 6 e geographic 1 7 n magnetic dip latitude are presented to illustrate two key findings 1 lsws appears to play a more important role in the development of esf than the post sunset rise pssr of the f layer and 2 lsws can appear well before e region sunset other findings that lsws does not have significant zonal drift in the initial stages of growth and can have zonal wavelengths of several hundred kilometers corroborate earlier reports

estimates of the precision of gps radio occultations from the cosmic formosat 3 mission 1 the constellation observing system for meteorology ionosphere and climate cosmic formosa satellite 3 formosat 3 is a six satellite radio occultation mission that was launched in mid april 2006 the close proximity of the cosmic satellites provides a unique opportunity to estimate the precision of the radio occultation remote sensing technique from closely collocated occultations 10 km separation of tangent points the rms difference of refractivity between 10 and 20 km altitude is less than 0 2 which is approximately twice better than previous estimates obtained from champ and sac c collocated occultations apparently due to smaller separation of the occultation pairs and due to parallel occultation planes in the lower troposphere the maximal rms is 0 8 at 2 km altitude and decreases abruptly to 0 2 between 6 and 8 km altitude the rms difference of electron density in the ionosphere between 150 and 500 km altitude for collocated occultations is about 103 cm 3

some characteristics of spread f at the magnetic equatorial station fortaleza spread f in ionograms of both the range and frequency spread types is studied for the magnetic equatorial station fortaleza geographic coordinates 38 w 4 s dip latitude 1 7 for a 1 year period during 1978 1979 satellite traces suggesting ionization structures with scale sizes of 100 200 km are found to be necessary precursors to the formation of the irregularities that give rise to range type spread f whereas frequency type spread f was observed under different circumstances striking differences are noted in the spread f characteristics and related parameters over fortaleza as compared with huancayo geographic coordinates 75 3 w 12 05 s dip latitude 0 6 and jicamarca geographic coordinates 76 8 w 11 95 s dip latitude 0 9 situated within only 38 in longitude west of fortaleza the postsunset maximum in h f in winter is delayed by about 1 hr with respect to other seasons over fortaleza as compared with huancayo where it occurs earlier in winter than in other seasons similar differences also exist in the prereversal peak near sunset in the vertical drift velocity vz between fortaleza and jicamarca the differences are attributed possibly to the large difference in the magnetic field declination and to other factors such as the difference in the magnetic field intensity and the relative separation between geographic and magnetic equators that exist between fortaleza and the other stations

the timescale and mechanism of granulite formation at kurunegala sri lanka incipient charnockite formation at kurunegala in sri lanka is characterized by the growth of orthopyroxene at the expense of amphibole and biotite in an originally homogeneous gneiss mineral equilibria in the charnockite assemblage record pressure temperature p t conditions of 738 60 c and 6 9 1 2 kbar at 17 0 1 2 log fo2 and ah2o 0 18 0 16 wholerock trace element and isotopic measurements show that charnockite formation was accompanied by a systematic depletion of sm rb pb u sr nd with a fractionation of rb sr sm nd and th u ratios and crystallization of the charnockite assemblage at 535 5 ma major element fe mg ca and sm nd equilibration between minerals occurred at 524 9 ma whereas pb and rb sr underwent continued exchange to 501 5 ma and 486 1 ma respectively trace element data for both amphibolite and charnockite minerals show that depletion on a whole rock scale can be accounted for either by changes in mineral modes or trace element abundances within the immediate area of dehydration the fractionation of sm nd on a whole rock scale is controlled by the breakdown of amphibole without the growth of a major new host phase for sm in the charnockite rubidium and sr are dependent on the relative behaviour of biotite plagioclase and alkali feldspar modelling of dehydration melting involving the breakdown of amphibole biotite and alkali feldspar reproduces the observed sm nd and rb sr fractionation and indicates the loss of small melt fractions on a cm scale from the charnockite these observations suggest that partial melting is the most plausible means of effecting both the dehydration and depletion that accompanies charnockite formation

aeolian modification of moraine soils whiskey basin wyoming usa soils along catenas of pinedale 15 20 ka and bull lake 100 130 ka age moraines at whiskey basin in the wind river range wyoming usa were sampled to assess the effects of aeolian processes on soil development here aeolian processes appear to have in uenced soils by both depositing sediments and eroding topsoils pedogenic silt often used as an indicator of wind deposition accumulated in the bull lake soils moderately correlate with pedogenic clay accumulated suggesting that ne sediments may have been deposited and incorporated into soil formation here following removal of previous topsoil by wind during pinedale glaciation bull lake b horizons have developed into contemporary a horizons these data further link aeolian processes to soil development on piedmont moraines throughout the wind river range copyright 2004 john wiley sons ltd

soil erosion along a transect in a forested catchment recent or ancient processes abstract forested areas are assumed not to be influenced by erosion processes however forest soils of northern germany in a hummocky ground moraine landscape can sometimes exhibit a very shallow thickness on crest positions and buried soils on slope positions the question consequently is are these on going or ancient erosional and depositional processes plutonium isotopes act as soil erosion deposition tracers for recent last few decades processes here we quantified the 239 240pu inventories in a small forested catchment ancient forest melzower forst deciduous trees which is characterised by a hummocky terrain including a kettle hole soil development depths depth to c horizon and 239 240pu inventories along a catena of sixteen different profiles were determined and correlated to relief parameters moreover we compared different modelling approaches to derive erosion rates from pu data we find a strong relationship between soil development depths distance to sink and topography along the catena fully developed retisols thicknesses 1 m in the colluvium overlay old land surfaces as documented by fossil ah horizons however we found no relationship of pu based erosion rates to any relief parameter instead 239 240pu inventories showed a very high local spatial variability 36 70 bq m 2 low annual rainfall spatially distributed interception and stem flow might explain the high variability of the 239 240pu inventories giving rise to a patchy input pattern different models resulted in quite similar erosion and deposition rates max 5 t ha 1 yr 1 to 7 3 t ha 1 yr 1 although some rates are rather high the magnitude of soil erosion and deposition in terms of soil thickness change is negligible during the last 55 years the partially high values are an effect of the patchy pu deposition on the forest floor this forest has been protected for at least 240 years therefore rather natural events and anthropogenic activities during medieval times or even earlier must have caused the observed soil pattern which documents strong erosion and deposition processes

geomagnetic conjugate observations of equatorial airglow depletions 1 we report for the first time large scale equatorial f region airglow depletions extending to low midlatitudes in both hemispheres the observational sites were located at low midlatitude geomagnetic conjugate points clear depletions of 630 0 nm airglow intensity due to equatorial plasma bubbles were simultaneously observed with two all sky imagers at sata japan magnetic latitude 24 n and its geomagnetic conjugate point darwin australia magnetic latitude 22 s on the night of november 12 2001 airglow depletion regions with east west scale sizes of 40 100 km extend poleward the maximum apex altitude of the plasma bubbles is about 1 700 km over the geomagnetic equator the depletions move eastward at about 100 m s without changing their structures the darwin depletion structures mapped onto the northern hemisphere along the geomagnetic field coincide closely with structures in the sata images even for the 40 km structure these observations indicate that plasma depletions in the equatorial ionosphere elongate along the geomagnetic field lines

medium scale traveling ionospheric disturbances triggered by super typhoon nepartak 2016 two remarkable typhoon induced traveling ionospheric disturbances tids with concentric and northwest southeast nw se alignments respectively associated with concentric gravity waves cgws and ionosphere instabilities possibly seeded by cgws were observed in total electron content tec derived from ground based gnss networks in taiwan and japan when the category 5 super typhoon nepartak approached taiwan on 7 july 2016 the concentric tids ctids first appear with horizontal phase velocities of 161 200 m s horizontal wavelengths of 160 270 km and periods of 15 22 min during 08 00 11 20 ut following the ctids the nw se aligned nighttime medium scale tids mstids are formed on the west edge of the ctids over the taiwan strait during 11 30 14 00 ut it is suggested that the mstids are produced by the electrodynamical coupling of perkins instability and cgw induced polarization electric fields this study proposes connections of typhoon induced ctids and subsequently occurring mstids in the low latitude ionosphere

on the generation and growth of equatorial backscatter plumes 1 wave structure in the bottomside f layer we examine the initial conditions that lead to backscatter plume development in the equatorial f region ionosphere by analyzing altair radar data we obtained the following principal results 1 prior to plume development an altitude modulation of electron density contours exists in the bottomside f layer these quasi periodic variations were mapped spatially over a 1200 km east west distance by using incoherent scatter measurements and found to consist of three cycles with an average spatial wavelength of 400 km 2 the wave structure observed in the bottomside electron density contours grew in amplitude at a rate consistent with that predicted by the generalized gradient drift instability 3 bottomside backscatter developed on the west walls of all three altitude modulated regions followed by plume development from near the crests of these regions

metamorphic fluids in the deep crust evidence from the adirondacks unusual mineral assemblages of tremolitic hornblende diopside enstatite quartz have been examined to estimate the temperature t and water fugacity at the time of the granulite fades metamorphism in the adirondacks the pyroxenes are closely represented by the system cao mgo sio2 allowing application of experimental data1 with only small corrections for reduced values of activities tremolite equilibria2 buffered log 3 0 0 1 equivalent to 0 9 kbar of water pressure at 7 kbar 710 c nearby marbles contain wollastonite calcite quartz and buffered 1 1 kbar consistent with 5 9 kbar inferred local gradients in fluid compositions suggest that deep crustal fluid conditions are complex and heterogeneous indicating that fluid movements whether of mantle3 or deep crustal origin are channelized rather than pervasive thus some granulite facies rocks were wholly or partly closed systems with respect to externally derived fluids permitting localized buffering of fluid compositions recognition of restricted fluid mixing limits theories that call for massive amounts of pervasive fluid flow to facilitate melting cause metasomatism or to stabilize granulite facies mineralogy

water activity changes across an amphibolite granulite facies transition broken hill australia phase compositions in pelitic and mafic gneisses place tight constraints on pressure ranging from 3 up to 6 kb and to a lesser extent on temperature 500 up to 800 c during prograde regional metamorphism of the willyama complex broken hill se australia these limits allow an evaluation of water activity across the terrain using various equilibria in pelitic and mafic gneisses the stability of cummingtonite and biotite over much of the terrain places upper limits on temperature and the presence of syn metamorphic partial melts in the metasediments places lower limits on a h2o garnet biotitesillimanite k feldspar quartz relations combined with the partial melting data suggest a decrease in water activity from near 1 0 in the lower grade zones to 0 5 0 2 in the broken hill little broken hill part of the two pyroxene zone this result is compatible with less precise hornblende orthopyroxene clinopyroxene quartz relations

effects of climate change on soils in glacial deposits wind river basin wyoming abstract soil chronofunctions are often quasilinear but those relationships may be only gross fortuitous generalizations that ignore changes in soils resulting from climatic and other cyclic external influences that govern soil formation or soil degradation in the rocky mountains soil development has been extensively used to estimate the age of sediments but the number of soils is usually few and large ranges in values for soil data may be dismissed as normal variation in a detailed study of soils in the wind river range and wind river basin characteristics of near surface horizons do not follow age trends however the underlying carbonate bearing horizons do have age related characteristics this soil paradox may be related to glacial interglacial cycles in which 1 wind erodes near surface horizons and then provides new parent material and 2 cryoturbation disrupts carbonate horizons remobilizing carbonate and changing carbonate morphology but with only minimal loss of carbonate from the soil

geomagnetic effects on time integrated cosmogenic nuclide production with emphasis on in situ 14c and 10be abstract production of cosmogenic nuclides cns in geologic material is a function of the cosmic ray flux at the earth s surface which in turn is a function of the intensity and orientation of the earth s geomagnetic field temporal variations in the intensity of the geomagnetic field and the position of the geomagnetic dipole axis i e polar wander must be considered when calculating production rates that are integrated through time we have developed a model based in part on protocols set forth by desilets and zreda earth planet sci lett 206 2003 21 42 that accounts for these variations in an effort to systematically determine their impact on time integrated production of short lived in situ 14c t1 2 5 73 ka and long lived in situ 10be t1 2 1 5 ma cns our modeling results show that for samples exposed for the last 3 ka integrated in situ 14c and 10be production rates that account for temporal variations in the intensity of the earth s geomagnetic field are up to 13 lower than modern rates at the same location modern rates are referenced to the 1945 0 definitive geomagnetic reference field dgrf in contrast intensity corrected 10be rates are up to 30 higher than modern for samples exposed for 25 30 ka intensity variations have little effect our modeling results also show that the impact of polar wander on integrated cn production is secondary compared to intensity variations accounting for polar wander is critical however when determining modern production rates at midlatitudes 30 40 because of the current offset between the geomagnetic and geographic poles at sea level integrated in situ 14c production rates that account for both intensity variations and polar wander range from 27 higher to 24 lower than modern rates at the same location and integrated in situ 10be rates range from 48 higher to 26 lower than modern differences between integrated and modern rates increase significantly at higher altitudes based on these results we recommend correcting the modern production rate referenced to the 1945 0 dgrf or another specific geomagnetic reference field at site latitudes

simultaneous observations of convective gravity waves from a ground based airglow imager and the airs satellite experiment 1 we report the first joint observations of convectively generated gravity waves gws using an oh airglow imager in colorado and the atmospheric infrared sounder airs onboard the aqua satellite convective gws appearing as concentric rings are observed over the western great plain regions of north america in the evening of 3 june 2008 in the airglow images inspecting both weather radars and airs radiances at 8 1 m strong convective clouds are found near the center of the concentric rings the airs data at 4 3 m show semicircular gws with horizontal wavelengths of 60 80 km at 0900 ut whereas the airglow imager observed circular gws with horizontal wavelengths of 44 km and airglow emission perturbation of 6 at the same geographic location at 0910 ut large scale gws horizontal wavelengths greater than 100 km emanating northwestward can be seen in both airs data and airglow images at different times the imager observed small scale ripples associated with unstable concentric gws in the mesopause in the early evening given that the brightness temperature perturbation of the gws in the airs data is about 0 16 k and assuming that the gws propagate without dissipation from the stratosphere to the upper mesosphere the expected airglow emission perturbation caused by the gws would be 4 17 ray tracing simulations are performed to demonstrate that the gws seen in airs and in the imager were likely excited by the same convective system

characteristics of large scale wave structure observed from african and southeast asian longitudinal sectors the spatial large scale wave structure lsws at the base of f layer is the earliest manifestation of seed perturbation for rayleigh taylor instability hence found to play a deterministic role in the development of equatorial plasma bubbles epbs except for a few case studies a comprehensive investigation has not been conducted on the characteristics of lsws because of the complexity involved in detecting the lsws particularly in spatial domain in this scenario a comprehensive study is carried out for the first time on the spatial and temporal characteristics of lsws observed in spatial domain over african and southeast asian longitudinal sectors during the year 2011 the observations indicate that these wave structures can be detected a few degrees west of e region sunset terminator and found to grow significantly at longitudes past the sunset terminator the phase fronts of these spatial structures are found to align with the geomagnetic field b lines over a latitudinal belt for at least 5 6 500 600 km centered on dip equator the zonal wavelengths of these structures are found to vary from 100 to 700 km which is consistent with the earlier reports and the epbs were consistently observed when the amplitudes of lsws were grown to sufficient strengths these results would provide better insights on the underlying physical processes involved in excitation of lsws in terms of important roles being played by e region electrical loading and polarization electric fields induced via spatially varying dynamo current due to neutral wind perturbations associated with atmospheric gravity waves

time temperature relation of mineral isochrons a thermodynamic model and illustrative examples for the rbsr system abstract we have developed a thermodynamic model for the determination of the closure temperature t c at which the minerals defining an internal isochron in rb sr or similar geochronological system were set with a geochronological clock it is shown that the equilibrium fractionation of 87 rb and 87 sr between a pair of minerals at t c k d 87 rb 87 sr c is given by the ratio of the quantity 87 rb 86 sr in the two minerals as measured at the present time k d 87 rb 87 sr which equals the element distribution coefficient k d rb sr under equilibrium condition can be calibrated as a function of temperature and compared with the retrieved value of k d 87 rb 87 sr c in a natural pair to obtain t c the various mineral pairs defining an internal isochron will yield concordant or discordant values of t c depending on whether or not they closed simultaneously with respect to the diffusion of rb and sr both types of results are expected and are important in the analyses of the evolutionary history of the host rocks preliminary analyses of the published data in the rb sr system suggest a fairly wide range of t c even for the same mineral pair reflecting differences in the cooling rates and physico chemical environments of the host rocks

smnd isotopic systematics of enderby land granulites and evidence for the redistribution of sm and nd during metamorphism measurements of143nd 144nd and147sm 144nd are reported for whole rocks and mineral separates from granulites of the napier complex at fyfe hills charnockites leuconorites and gabbros yield a whole rock smnd isochron age of3060 160m y and an initial143nd 144nd ratio of0 50776 10 nd 3060m y 2 0 1 8 the negative nd value and the presence of geologically induced dispersion in the data suggest that the isochron age does not represent the time of primary crystallization of the complex but instead indicates a time of later redistribution of sm and nd and partial re equilibration of143nd 144nd ratios this probably occurred during the upper granulite facies metamorphism which has also been dated at 3100m y by rbsr and upb zircon studies 1 coexisting clinopyroxene apatite and total rock fractions in two adjacent samples define an approximately linear array corresponding to an age of 2300 300 m y this array indicates that redistribution of sm and nd and re equilibration of143nd 144nd ratios occurred on an intermineral scale during the upper amphibolite to lower granulite facies metamorphism at 2450m y due to the resetting of the smnd system on both whole rock and mineral scales the primary crystallization age of the igneous protolith is not well constrained by the present data although it is clearly3100m y if it is assumed that the complex was derived initially from a depleted mantle reservoir nd t 2 evolution of the negative nd value of 2 0 with the observed sm nd ratios requires a prehistory of 380m y this implies a primary age of 3480m y however substantially older primary ages can be inferred if the source reservoirs had nd t 2 and or substantial reductions in the sm nd ratio occurred in whole rocks during the granulite facies metamorphism at 3100 m y such an inferred reduction in the sm nd ratio may have been the result of preferential loss of sm relative to nd or introduction of a low sm nd fluid with nd 0 during granulite facies metamorphism

glacial stratigraphy of stough creek basin wind river range wyoming abstract multiparameter relative age ra techniques identify four post pinedale morphostratigraphic units in each of three cirque valleys tributary to stough creek basin wind river range wy soil development lichenometry boulder weathering characteristics and the geomorphic relations among morphostratigraphic units indicate glacial deposits here correspond to the sequence previously described in the temple lake valley arct alp res 6 1974 301 cirque deposits in stough creek basin correspond to the temple lake alice lake black joe and gannett peak alloformations gsa abs prog 32 2000 a 16 10 be ages from moraine boulders and polished striated bedrock assoc am geogr annu mtg abs 2000 155 support recent numeric age estimates from temple lake and titcomb basin that indicate the temple lake alloformation corresponds to the younger dryas climate episode geogr phys quat 41 1987 397 geology 23 1995 877 science 268 1995 1329 gsa abs prog 31 1999 a 56 soils described from pinedale recessional deposits here represent the first systematic description of pinedale alpine deposits in the wrr

a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice core records refining and extending the intimate event stratigraphy due to their outstanding resolution and well constrained chronologies greenland ice core records provide a master record of past climatic changes throughout the last interglacial glacial cycle in the north atlantic region as part of the intimate integration of ice core marine and terrestrial records project protocols have been proposed to ensure consistent and robust correlation between different records of past climate a key element of these protocols has been the formal definition and ordinal numbering of the sequence of greenland stadials gs and greenland interstadials gi within the most recent glacial period the gs and gi periods are the greenland expressions of the characteristic dansgaard oeschger events that represent cold and warm phases of the north atlantic region respectively we present here a more detailed and extended gs gi template for the whole of the last glacial period it is based on a synchronization of the ngrip grip and gisp2 ice core records that allows the parallel analysis of all three records on a common time scale the boundaries of the gs and gi periods are defined based on a combination of stable oxygen isotope ratios of the ice 18o reflecting mainly local temperature and calcium ion concentrations reflecting mainly atmospheric dust loading measured in the ice the data not only resolve the well known sequence of dansgaard oeschger events that were first defined and numbered in the ice core records more than two decades ago but also better resolve a number of short lived climatic oscillations some defined here for the first time using this revised scheme we propose a consistent approach for discriminating and naming all the significant abrupt climatic events of the last glacial period that are represented in the greenland ice records the final product constitutes an extended and better resolved greenland stratotype sequence against which other proxy records can be compared and correlated it also provides a more secure basis for investigating the dynamics and fundamental causes of these climatic perturbations

on monthly seasonal longitudinal variations of equatorial irregularity occurrences and their relationship with the postsunset vertical drift velocities 1 monthly variation of global equatorial density irregularity distribution has been obtained with the data taken by rocsat 1 at the 600 km topside ionosphere from march 1999 to june 2004 during high to moderate solar activity years this global distribution of monthly irregularity occurrence rate not only provides the best spatial temporal distribution in existence so far but also serves to fill the gap of irregularity distribution missing over some eastern pacific region where no ground observation is available the 5 1 2 year result of the monthly occurrence pattern indicates a smooth variation across the longitudes contrary to some beliefs that a drastic change in irregularity occurrence pattern has occurred across the eastern pacific longitudes excellent agreement is noted for the current results with aarons 1993 conjectured sketch of the global scintillation distribution furthermore the seasonal longitudinal s l variations of quiet time postsunset vertical drift velocities are found to track closely with the s l variations of irregularity occurrences linear regression analysis between the vertical drift velocity and the irregularity occurrence rate indicates that the vertical drift velocities at three different longitude zones of magnetic declination have good correlations with the irregularity occurrences for all seasons this implies that the averaged postsunset vertical drift velocity is a good indicator for the occurrences of equatorial density irregularities in a longitude region of similar magnetic declination the smooth variation of monthly seasonal longitudinal distributions of the vertical drift velocities that results in the smooth variation of topside density irregularity occurrences implies that the global occurrence pattern of either distribution is controlled by the smooth global variation of the postsunset ionospheric condition related to the magnetic declination effect and the seasonal variation of the ionospheric density level at the dip equator located with respect to the geographic equator there seems little need to include the global distribution of instability perturbation seeds from atmospheric disturbances to complete the global distribution of topside irregularity occurrences

evolution of soil erosion rates in alpine soils of the central rocky mountains using fallout pu and δ13c abstract data from soil chronosequences have been widely used to quantify soil formation and weathering rates but are less used to determine erosion rates and the stabilisation of moraines over time we hypothesise that soil erosion rates on moraine hillslopes decrease over time as soils evolve and slopes stabilise we selected a sequence of moraines in the wind river range central rocky mountains to study these processes over time moraine ages were based on 10be surface exposure dating of moraine boulders quantitative soil erosion and accumulation rates along slopes with similar exposures lengths and gradients were determined from profile patterns of 239 240pu radionuclides we used stable carbon isotopes 13 c in relation with the total soil organic carbon soc content for qualitative information about soil erosion the 10be boulder exposure ages revealed that the moraines were deposited during the younger dryas and the pre bolling allerod episodes of the late pleistocene the morphology of the soils suggests a complex history of development and shows that both erosion and aeolian deposition have affected the soils the 239 240pu measurements revealed that erosion rates strongly decrease with time as soils develop a weakly developed soil cambisol is found on the youngest moraine 11 8 ka that exhibits an erosion rate depending on the calculation procedure in the range of 260 to 520 t km 2 a 1 with time the erosion rate rapidly decreases to almost zero presumably as a full vegetation cover develops bioturbation and or dust influx is increasingly obvious with increasing age of the soils as evidenced by the comparison of 13 c and soc the mass balance of the oldest soil 15 8 ka indicates that the slopes have reached a geomorphological stability with little or no net erosion aeolian influx appears to be the primary factor to account for mass changes in the oldest soil

a global perspective on last glacial maximum to holocene climate change while the abrupt climate events of the last deglaciation are well defined in ice core records from the polar regions of both hemispheres their manifestation elsewhere is less well constrained here we compile 104 high resolution paleoclimate records to characterize the timing and spatial pattern of climate change during the last deglaciation this compilation indicates relatively concurrent timing of the last glacial maximum lgm peak glacial conditions and the altithermal peak interglacial conditions in the northern 22 1 4 3 ka and 8 0 3 2 ka and southern 22 3 3 6 ka and 7 4 3 7 ka hemispheres suggesting the hemispheres were synchronized by greenhouse gases local insolation and or northern hemisphere induced ocean circulation changes the magnitude of the glacialeinterglacial temperature change increases with latitude reflecting the polar amplification of climate change with a likely minimum global mean cooling of ww4 9 c during the lgm relative to the altithermal empirical orthogonal function eof analysis of 71 records spanning 19e11 ka indicates that two modes explain 72 of deglacial climate variability eof1 61 of variance shows a globally near uniform pattern with its principal component pc1 strongly correlated with changes in atmospheric co2 e of2 11 of variance exhibits a bipolar seesaw pattern between the hemispheres with its principal component pc2 resembling changes in atlantic meridional overturning circulation strength eof analysis of 90 records from 15 to 11 ka indicates that northern and southern modes of climate variability characterize the younger dryas bolling allerod interval these modes dominate at the higher latitudes of each hemisphere and exhibit a complex interaction in the tropics the magnitude of the younger dryas climate anomaly cooler drier increases with latitude in the northern hemisphere with an opposite pattern warmer wetter in the southern hemisphere reflecting a general bipolar seesaw climate response global mean temperature decreased by w0 6 c during the younger dryas therefore our analysis supports the paradigm that while the younger dryas was a period of global climate change it was not a major global cooling event but rather a manifestation of the bipolar seesaw driven by a reduction in atlantic meridional overturning circulation strength

radar and satellite global equatorial f region vertical drift model we present the first global empirical model for the quiet time f region equatorial vertical drifts based on combined incoherent scatter radar observations at jicamarca and ion drift meter observations on board the atmospheric explorer e satellite this analytical model based on products of cubic b splines and with nearly conservative electric fields describes the diurnal and seasonal variations of the equatorial vertical drifts for a continuous range of all longitudes and solar flux values our results indicate that during solar minimum the evening prereversal velocity enhancement exhibits only small longitudinal variations during equinox with amplitudes of about 15 20 m s is observed only in the american sector during december solstice with amplitudes of about 5 10 m s and is absent at all longitudes during june solstice the solar minimum evening reversal times are fairly independent of longitude except during december solstice during solar maximum the evening upward vertical drifts and reversal times exhibit large longitudinal variations particularly during the solstices in this case for a solar flux index of 180 the june solstice evening peak drifts maximize in the pacific region with drift amplitudes of up to 35 m s whereas the december solstice velocities maximize in the american sector with comparable magnitudes the equinoctial peak velocities vary between about 35 and 45 m s the morning reversal times and the daytime drifts exhibit only small variations with the phase of the solar cycle the daytime drifts have largest amplitudes between about 0900 and 1100 lt with typical values of 25 30 m s we also show that our model results are in good agreement with other equatorial ground based observations over india brazil and kwajalein

revised quaternary glacial succession and post lgm recession southern wind river range wyoming usa abstract we present here a more complete cosmogenic chronology of pleistocene glacial deposits for the wind river range wyoming usa fifty one new and thirty nine re calculated 10be and 26al exposure ages from sinks and north fork canyons stough basin cirque of the towers and the temple lake valley allow us to more tightly constrain the timing and sequence of glacial alloformations in the southern portion of the range moraines diamicts and bedrock exposures here have previously been correlated with as many as five pleistocene and four holocene glacial events exposure ages from pleistocene alloformations associated with trunk glaciers in sinks canyon and north fork canyon generally confirm earlier age estimates cosmogenic radionuclide crn 10be and 26al ages from moraines and striated bedrock surfaces previously mapped as pinedale correspond to mis2 while boulder exposure ages from moraines mapped as bull lake correspond generally to mis5 mis6 geomorphic data from a moraine previously mapped as younger pre sacagawea ridge appears to correspond most closely to the sacagawea ridge glacial episode mis 16 but the uncertainty of a single 10be exposure age suggests the unit could be as young as mis 10 or as old as mis 18 boulders from a diamict on table mountain previously reported as older pre sacagawea ridge yield two 10be exposure ages that suggest the presence of early pleistocene glacial activity here possibly older than 1 2 ma mis 30 bedrock exposure ages within sinks canyon suggest the pinedale valley glacier had retreated from the floor of sinks canyon to above popoagie falls by ca 15 3 ka cirque glaciers in stough basin appear to have retreated behind their riegels by ca 16 ka which suggests the cirque glaciers were decoupling across their riegels from the valley glaciers below at this time prior to their readvance to form lateglacial moraines new 10be boulder exposure ages from moraines previously correlated to the temple lake and alice lake allostratigraphic units in the cirques of stough basin and cirque of the towers show general equivalence to the stadial event just prior to the onset of the bolling interstadial 17 5 14 7 ka and to the intra allerod cold period younger dryas stadial phase 13 9 11 7 ka respectively from this evidence the temple lake alloformation of the wind river mountains now should correspond to the intimate gs 2 1a oldest dryas stadial event while the alice lake alloformation should correspond to the intimate gs 2 stadial iacp younger dryas thus we consider that evidence no longer exists for early to mid holocene glacial events in the southern wind river range

concentric gravity waves in the mesosphere generated by deep convective plumes in the lower atmosphere near fort collins colorado 1 gravity waves in the mesopause region 80 105 km may induce perturbations in oh meinal band emissions at 87 km these perturbations can be observed by ground based oh airglow imagers in this paper we present observations of concentric gravity waves cgw by the all sky oh imager at yucca ridge field station 40 7 n 104 9 w near fort collins colorado we find that expanding rings of concentric gravity waves were observed on 9 out of 723 clear nights from 2003 to 2008 in particular on 11 may 2004 concentric rings were observed for 1 5 h with nearly perfect circular rings entirely in the field of view during the first 30 min the centers of the concentric rings occurred at the geographic locations of two strong convective plumes which were active in the troposphere 1 h earlier we measured the horizontal wavelengths and periods of these gravity waves as functions of both radius and time these results agreed reasonably well with the internal boussinesq gravity wave dispersion relation with an assumed zero background wind similarly for the other 8 cases strong convective plumes occurred prior to the cgw observations near the apparent center of each of the arcs or rings for the 7 out of the 9 cases radiosonde data were available up to z 30 35 km these data showed that the wind speeds from the tropopause to 30 35 km were smaller than 20 30 m s because 8 of the 9 cases occurred when the total horizontal mean winds were weak and because the horizontal winds below 87 km were less than 20 m s on 11 may 2004 according to radiosonde and time gcm model data we postulate that weak background horizontal winds are likely a necessary condition for gravity waves excited from convective overshooting to be observed as concentric arcs or rings in the oh layer

motions of the equatorial ionization anomaly crests imaged by formosat 3 cosmic 1 the equatorial ionization anomaly eia structures and evolutions are imaged using radio occultation observation of the newly launched formosat 3 cosmic f3 c satellite constellation three dimensional ionospheric images provide unprecedented detail of the eia structure globally this paper presents images of the eia structures during july august 2006 and discusses the development and subsidence of the eia clear seasonal asymmetries in both ionospheric electron density and layer height are observed two dimensional cross section maps at a meridian provide dynamic variations and motions of the northern and southern eia crests results suggest that in addition to the asymmetric neutral composition effect interactions between the summer to winter transequatorial neutral winds and strength of the equatorial plasma fountain effect play important roles in producing asymmetric development of the eia crests as imaged by the f3 c

on the enigma of day to day variability in equatorial spread f 1 we show that large scale wave structure lsws in plasma density in the bottomside f layer is a hitherto unheralded contributor to the long standing enigma of day to day variability in equatorial spread f esf little is known about lsws it seems to appear in altitude near a vertical shear in zonal plasma drift during the post sunset rise of the f layer and its growth via an interchange instability appears to predispose quasi periodically spaced regions to development of plasma bubbles first indications are that lsws development is necessary and sufficient for esf occurrence we suggest that variability in lsws development perhaps together with the shear in zonal drift may contribute to day to day esf variability a need revealed by this study is that a cluster of distributed sensors not isolated ones is necessary to pursue the problem of day to day variability