linear coupling of carbon and strontium isotopes in rotliegend sandstone north sea evidence for cross formational fluid flow isotopic analyses of carbon and strontium in diagenetic dolomite and ankerite present in the eolian lower permian rotliegend sandstone southern north sea show an excellent linear correlation between delta sup 13 c and sup 87 sr sup 86 sr r 0 93 suggesting that the sources of these elements were interlinked the isotopic data indicate that late permian zechstein seas flooded the basin and displaced the interstitial meteoric rotliegent pore fluids producing early dolomite with predominantly marine bicarbonate delta sup 13 c minus 15 per thousand and strontium sup 87 sr sup 86 sr 0 7076 isotopic signatures the isotopic values of this dolomite form a trend to merge with the diagenetically later ankerite which has lower sup 13 c sup 12 c delta sup 13 c minus 4 per thousand and more radiogenic strontium sup 87 sr sup 86 sr 0 7112 the obvious source of low delta sup 13 c carbon was thermal decarboxylation of organic matter in the underlying upper carboniferous mudstones the authors also suggest that the increasing quantities of radiogenic strontium sup 87 sr sup 86 sr 0 720 were released when organic acids dissolved silicates feldspar in the same underlying mudstones the upward movement of fluid or diffusion of ions across formation boundaries therefore progressively became the dominant control on carbonate precipitation in the rotliegend sandstone

an algorithm for extracting zonal mean and migrating tidal fields in the middle atmosphere from satellite measurements applications to timed saber measured temperature and tidal modeling 1 for a data series with grid points that do not uniformly cover a whole wave cycle in both space and time traditional least squares fitting methods will lead to biased estimates of the zonal mean and wave components as a result of aliasing between these elements we introduce a set of formal regularity conditions to select available grid points that reduce aliasing while obtaining the zonal mean and tidal components from unevenly sampled or incomplete measurements the algorithm is used to self consistently investigate the effect of the zonal mean field on the seasonal variation of diurnal tide in the upper middle atmosphere using temperature measured by the sounding of the atmosphere using broadband emission radiometry saber instrument onboard the thermosphere ionosphere mesosphere energetics and dynamics timed satellite we first unbiasly derive both the zonal mean and migrating tidal components from the measurements then simulate the seasonal variation of the migrating diurnal tide using a spectral tidal model with the measured zonal mean as input and finally compare the seasonal variation of the measured tide with the modeled one the model and measurement comparisons show self consistently and more conclusively the dominant effect of the zonal mean wind on the seasonal variation of the migrating diurnal tide in the upper middle atmosphere

late anhydrite cements mark basin inversion isotopic and formation water evidence rotliegend sandstone north sea the lower permian rotliegend sandstone in the leman field today contains formation waters which are extremely saline 165 530 238 531 mg l with cation chloride ratios indicating mixing of zechstein marine evaporite brines with meteoric water ancient rotliegend formation waters inferred from the analyses of cements were similarly a mixture of marine brine and meteoric water 18o 0 3 smow d 16 smow the strontium isotopic compositions of present day formation waters 87sr 86sr 0 7107 are also consistent with mixing between late permian marine brines 87sr 86sr 0 707 and radiogenic strontium from a detrital source 87sr 86sr 0 720 0 730 isotopic analyses of texturally late intergranular and fracture filling anhydrite suggest waters very similar to the present day formation waters 34s values of anhydrite cements 10 cdt indicate that sulphate in the rotliegend originated from the stratigraphically overlying zechstein evaporites the 87sr 86sr 150 ratios of anhydrites 0 7080 0 7113 however suggest variable mixing of strontium sourced from the overlying zechstein evaporites with more radiogenic strontium derived from diagenetic reactions in the underlying carboniferous shales the oxygen isotope compositions of anhydrite reflect precipitation temperatures between 120 and 140 c from waters with a 18o composition similar to the present day formation waters approximately 0 smow these are the maximum inferred burial temperatures for the rotliegend sandstone in the leman field and would have occurred at maximum burial depths of 3 5 4 km 11 500 13 100 ft during the late jurassic early cretaceous at the start of basin inversion these data indicate an unusual short lived catastrophic event of cross formational flow through fractures which were tectonically induced by basin inversion pore fluids may have escaped from the overlying and underlying formations into the lower pressure rotliegend sandstone regional aquifer to drain this part of the basin

detection of migrating diurnal tide in the tropical upper troposphere and lower stratosphere using the challenging minisatellite payload radio occultation data 1 the atmospheric limb sounding technique making use of radio signals transmitted by the global positioning system gps has already proven to be a promising approach for global atmospheric measurements in this study we assess for the first time the potential of gps radio occultation soundings for detecting the migrating diurnal tide retrieved temperatures between 10 and 30 km in the tropics from the challenging minisatellite payload champ occultation observations during may 2001 to august 2005 are analyzed using space time spectrum analysis to isolate diurnal waves because of incomplete local time lt coverage of the monthly champ occultation data in any given year data from all available years are merged to obtain complete 24 h lt coverage the effects of aliasing associated with uneven data sampling and measurement noise are estimated using synthetic data the results show the feasibility of determining tidal structures from the composite champ occultation data and the vertical seasonal and latitudinal structures of the diurnal tide are presented the estimated diurnal amplitude generally increases with altitude exhibiting a maximum of order 1 k at 30 km the estimated phase indicates an upward propagating mode above 14 km with a vertical wavelength about 20 km the observed diurnal tide at 30 km exhibits a distinct seasonallatitudinal variation comparison of the observed diurnal tide to the simulated tide in the extended canadian middle atmosphere model cmam and global scale wave model version 2 gswm02 indicates that cmam overestimates the amplitude but reproduces the seasonal latitudinal variation of the diurnal tide while gswm02 simulates well the annual mean amplitude but lacks the seasonal latitudinal variation of the diurnal tide

observations of the diurnal tide in the mesosphere and lower thermosphere over christmas island atmospheric tidal variations in the mesosphere wind field have been studied extensively using radars most of the climatological studies of the tide have been done at middle and high latitudes previous tropical observations of the diurnal oscillation derived from campaign studies have shown the dominance of the migrating diurnal tide in the mesosphere and lower thermosphere by using wind measurements obtained with a meteor radar system located at christmas island the diurnal tidal behavior in the upper atmosphere of the equatorial pacific has been characterized over several years the data collected from august 1988 to december 1993 are presented in this paper and compared to various model results our observations show the meridional wind component of the diurnal tide maximizes in april near 94 km the observed meridional vertical wavelengths are large and indicate upward propagating energy even though the vertical wavelengths for the zonal diurnal component are also large the phase progression is upward corresponding to downward propagating energy there is considerable interannual and intraseasonal variation in the diurnal amplitudes throughout the year

equatorial vertical drift modulation by the lunar and solar semidiurnal tides during the 2013 sudden stratospheric warming during the 2013 stratospheric sudden warming ssw period the jicamarca unattended long term investigations of the ionosphere and atmosphere julia radar at jicarmarca peru observed low latitude vertical drift modulation with lows of 0 12 m s daytime maximum drifts between 6 13 and 22 25 january and enhanced drifts up to 43 m s between 15 snd 19 january the ncar thermosphere ionosphere mesosphere electrodynamics general circulation model reproduces the prevailing vertical drift feature and is used to examine possible causes the simulations indicate that the modulation of the vertical drift is generated by the beating of the semidiurnal solar sw2 and lunar m2 tides during the ssw period the beating is observable since the magnitudes of lunar and solar semidiurnal tidal amplitudes are comparable the theoretical beating frequency between sw2 and m2 is 1 15 13 day which may be modified due to phase changes this study highlights the importance of the lunar tide during ssw periods and indicates that the equatorial vertical drift modulation should be observable at other longitudes as well

global ray tracing simulations of the saber gravity wave climatology 1 since february 2002 the saber sounding of the atmosphere using broadband emission radiometry satellite instrument has measured temperatures throughout the entire middle atmosphere employing the same techniques as previously used for crista cryogenic infrared spectrometers and telescopes for the atmosphere we deduce from saber v1 06 data 5 years of gravity wave gw temperature variances from altitudes of 20 to 100 km a typical annual cycle is presented by calculating averages for the individual calendar months findings are consistent with previous results from various satellite missions based on zonal mean saber data for july and zonal mean gw momentum flux from crista a homogeneous and isotropic launch distribution for the grograt gravity wave regional or global ray tracer is tuned the launch distribution contains different phase speed mesoscale waves some of very high phase speed and extremely low amplitudes as well as waves with horizontal wavelengths of several thousand kilometers global maps for different seasons and altitudes as well as time series of zonal mean gw squared amplitudes based on this launch distribution match the observations well based on this realistic observation tuned model run we calculate quantities that cannot be measured directly and are speculated to be major sources of uncertainty in current gw parameterization schemes two examples presented in this paper are the average cross latitude propagation of gws and the relative acceleration contributions provided by saturation and dissipation on the one hand and the horizontal refraction of gws by horizontal gradients of the mean flow on the other hand

a climatology of tides in the antarctic mesosphere and lower thermosphere 1 a function that approximates atmospheric tidal behavior in the polar regions is described this function is fitted to multistation radar measurements of wind in the mesosphere and lower thermosphere with the aim of obtaining a latitude longitude height description of the variation of tides over the whole antarctic continent archival wind data sets are combined with present day ones to fill the spatial distribution of the observations and to reduce the potential effects of spatial aliasing multiple years are combined through the compilation of monthly station composite days yielding results for each month of the year despite potential problems associated with year to year variations in the tidal phase a useful climatology of antarctic zonal and meridional tidal wind components is compiled the results of the fits reproduce the major features of the high latitude tidal wind field the dominance of the semidiurnal migrating mode in the winter months and the presence of a semidiurnal zonal wave number one component in the summer months it is also found that the summer semidiurnal tide contains a zonal wave number zero component

gravity wave interactions with the diurnal propagating tide observations of the diurnal propagating solar tide in the mesosphere and lower thermosphere 50 150 km indicate substantial annual variations in tidal amplitudes observations and modeling efforts suggest that interactions with internal gravity waves can result in significant modifications of the diurnal tide herein a two dimensional 2 d linear steady state tidal model is used in conjunction with hybrid lindzen matsuno gravity wave parameterization to examine the role of gravity wave interactions in the seasonal variability of the diurnal tide in the mlt the analysis indicates that annual variations of the background atmosphere result in significant annual variations in the eddy diffusion and the diurnal harmonic of the momentum flux divergence wave stress produced by breaking gravity waves the seasonal variability in these two mechanisms can explain the observed semi annual variability in the diurnal tide amplitude minima at solstice and maxima at equinox the relative roles of wave stress and diffusion are examined and it is shown that both play important roles in tidal modification by damping its amplitude the effects of varying inputs to the gravity wave parameterization are explored

evaluation of environmental seismic intensities of all known historical and recent earthquakes felt in zakynthos island greece using the environmental seismic intensity esi 2007 scale abstract the complete and detailed knowledge of the historical earthquakes the past earthquake environmental effects eee and the respective seismic intensities has become significant in recent years due to the fact that among others it serves as a valuable tool for revealing and highlighting sites of significant earthquake related hazards many efforts have been made to record the eee of individual recent earthquakes and evaluate their seismic intensity based on the environmental seismic intensity 2007 scale esi 2007 in greece and around the world but fewer studies have focused on the complete seismic history including historical and recent earthquakes of an area and the respective intensities based on the induced eee the central ionian islands western greece and especially zakynthos island are considered appropriate for the development of this approach the complete history of earthquakes with destructive impact on zakynthos from 1513 to present is presented emphasis is given on eee while the respective esi 2007 intensities are assigned based on the eee s distribution on the affected fault blocks it is concluded that eastern zakynthos has been affected more often and severely by earthquakes this selective distribution is attributed to the neotectonic setting of zakynthos the recording of the eee over the past five centuries and the study of possible correlation with the seismotectonic structure of the affected area could be used as a basic guide for the reduction of the future seismic risk and the risk from eee through effective land use planning and preparedness in earthquake prone areas

lidar observations of the middle atmospheric thermal tides and comparison with the high resolution doppler imager and global scale wave model 1 methodology and winter observations at table mountain 34 4 n the tidal signature in the middle atmospheric thermal structure was investigated using more than 140 hours of nighttime lidar measurements at table mountain 34 4 n during january 1997 and february 1998 the lidar profiles 30 85 km revealed the presence of persistent mesospheric temperature inversions around 65 to 70 km altitude with a clear local solar time lst dependence daytime temperature profiles 65 105 km obtained by the high resolution doppler imager hrdi on board the upper atmosphere research satellite uars in january and february from 1994 to 1997 and zonally averaged at the latitude of the table mountain facility tmf were considered together with the lidar results the daytime hrdi and nighttime lidar temperature differences from their respective daytime and nighttime averages were compared to the equivalent differences predicted by the global scale wave model gswm a remarkable consistency was observed between the lidar and the hrdi upper mesospheric thermal structure with a continuous downward propagation of warm temperatures from 100 km at 1000 lst to 75 km at 2000 lst and 65 70 km at 0300 0500 lst surrounded above and below by colder temperatures this structure was predicted by gswm but with a 2 to 4 hour delay and a weaker amplitude on the lower side of this structure i e 65 70 km a thin layer characterized by early night cold temperatures and late night warm temperatures was identified as the result of the downward propagation of the temperature inversions using a new analysis technique which we have named constrained wave adjustment for convenience in future reference and assuming that the observed temperature variability was entirely driven by tides some estimations of the diurnal and semidiurnal phases and amplitudes were made from the lidar measurements between 40 and 85 km altitude although it does not allow a complete and accurate extraction of the tidal components this new method appeared to work well for the present tmf study the estimated diurnal amplitude exhibited a minimum at 63 km with a fast phase transition characteristic of the transition between the upper stratospheric trapped modes phase at 1800 lst and the upward propagating modes this transition layer was predicted by gswm to be at 5 km lower altitude this altitude shift was present throughout the middle mesosphere immediately above the transition layer the very fast growing diurnal amplitude between 65 and 72 km was followed by a substantial decrease and by the emergence of the semidiurnal component resulting in the formation of the mesospheric temperature inversion layers however the amplitude of the inversions remained large compared to the theoretical tidal predictions and a different formation mechanism should possibly be considered recent modeling studies have shown that gravity wave breaking can be significantly affected by the tidal background winds and some preferential wave breaking times could emerge that are dependent on the phase of the diurnal tide and the characteristics of the dissipating waves this lst filtering could result in lst dependent temperature inversion layers similar to those observed by lidar the new analysis technique presented in this paper was also applied to study the temperature tidal oscillations at mauna loa observatory 19 5 n the results are presented in a companion paper leblanc et al this issue

new empirical relationships among magnitude rupture length rupture width rupture area and surface displacement source parameters for historical earthquakes worldwide are compiled to develop a series of empirical relationships among moment magnitude m surface rupture length subsurface rupture length downdip rupture width rupture area and maximum and average displacement per event the resulting data base is a significant update of previous compilations and includes the additional source parameters of seismic moment moment magnitude subsurface rupture length downdip rupture width and average surface displacement each source parameter is classified as reliable or unreliable based on our evaluation of the accuracy of individual values only the reliable source parameters are used in the final analyses in comparing source parameters we note the following trends 1 generally the length of rupture at the surface is equal to 75 of the subsurface rupture length however the ratio of surface rupture length to subsurface rupture length increases with magnitude 2 the average surface displacement per event is about one half the maximum surface displacement per event and 3 the average subsurface displacement on the fault plane is less than the maximum surface displacement but more than the average surface displacement thus for most earthquakes in this data base slip on the fault plane at seismogenic depths is manifested by similar displacements at the surface log linear regressions between earthquake magnitude and surface rupture length subsurface rupture length and rupture area are especially well correlated showing standard deviations of 0 25 to 0 35 magnitude units most relationships are not statistically different at a 95 significance level as a function of the style of faulting thus we consider the regressions for all slip types to be appropriate for most applications regressions between magnitude and displacement magnitude and rupture width and between displacement and rupture length are less well correlated and have larger standard deviation than regressions between magnitude and length or area the large number of data points in most of these regressions and their statistical stability suggest that they are unlikely to change significantly in response to additional data separating the data according to extensional and compressional tectonic environments neither provides statistically different results nor improves the statistical significance of the regressions regressions for cases in which earthquake magnitude is either the independent or the dependent parameter can be used to estimate maximum earthquake magnitudes both for surface faults and for subsurface seismic sources such as blind faults and to estimate the expected surface displacement along a fault for a given size earthquake

mean winds and tides in the arctic mesosphere and lower thermosphere 1 a new meteor radar has been deployed at esrange 68 n 21 e near kiruna in sweden the radar has been used to measure winds and tides in the arctic mesosphere lower thermosphere region over the interval august 1999 to july 2000 conspicuous features of the measured mean winds include a strong shear of up to 5 m s 1 km 1 in the summer zonal flow resulting in eastward flows of in excess of 30 m s 1 at the upper heights observed 97 km an equatorward meridional flow is observed in summer and winter which reaches maximum values of 13 m s 1 in a summer jet poleward flow in comparison is weak and only occurs at the equinoxes the monthly mean and seasonal mean behaviors of the amplitudes and phases of the 12 and 24 hour tides are examined and compared to the global scale wave model 98 the observations are generally very close to the model predictions for the 24 hour tide and for the 12 hour tide in winter in other seasons particularly summer the observed 12 hour tidal amplitudes are significantly larger than those predicted in spring and summer the wavelength of the 12 hour tide is significantly larger than that predicted

ground effects of the 18 october 1992 murindo earthquake nw colombia using the environmental seismic intensity scale esi 2007 for the assessment of intensity

global observations of 2 day wave coupling to the diurnal tide in a high altitude forecast assimilation system we examine wave components in a high altitude forecast assimilation system that arise from nonlinear interaction between the diurnal tide and the westward traveling quasi 2 day wave the process yields a westward traveling sum wave with zonal wavenumber 4 and a period of 16 hours and an eastward traveling difference wave with zonal wavenumber 2 and a period of 2 days while the eastward 2 day wave has been reported in satellite temperatures the westward 16 hour wave lies outside the nyquist limits of resolution of twice daily local time satellite sampling hourly output from a high altitude forecast assimilation model is used to diagnose the nonlinear quadriad a steady state primitive equation model forced by tide 2 day wave advection is used to intepret the nonlinear wave products the westward 16 hour wave maximizes in the midlatitude winter mesosphere and behaves like an inertia gravity wave the nonlinearly generated component of the eastward 2 day wave maximizes at high latitudes in the lower thermosphere and only weakly penetrates to low latitudes the 16 hour and the eastward 2 day waves are of comparable amplitude and alias to the same apparent frequency when viewed from a satellite perspective

evidence for resetting of fluid inclusion temperatures from quartz cements in oilfields abstract quartz is a major pore occluding cement in north sea oilfield reservoir sandstones fluid inclusions yield homogenization temperatures t h which have been thought to represent growth temperatures for the host quartz however early diagenetic inclusions from the detrital grain overgrowth boundary yield excessively high palaeotemperatures which do not match the growth temperatures calculated from the depth of cementation the temperatures of these inclusions increase with present day depth of burial and approach present day reservoir temperatures this suggests that the inclusions have begun to reset towards present day pressure temperature conditions the t h of the inclusions hence represent burial temperatures rather than growth temperatures for the quartz experimental studies indicate that the amount of resetting undergone by an inclusion varies depending on its size shape and fluid composition a relationship between inclusion t h and these variables has been observed in inclusions from deeply buried quartz cements in the north sea

mudstone sandstone ratio control on carbonate cementation and reservoir quality in upper permian rotliegend sandstones offshore the netherlands abstract the eolian fluvial sandstones of the upper permian rotliegend formation which were deposited in the southern permian basin are today deeply buried 3 4 km and constitute important gas reservoirs in the netherlands and the southern north sea the reservoir properties of the sandstones have been documented to be strongly affected by diagenesis but the primary diagenetic factors impairing reservoir quality and their cause remain variably interpreted in the literature here we present the results of a detailed investigation on the diagenetic processes controlling reservoir quality in the lower slochteren formation in the l and k blocks offshore the netherlands where fluvial and aeolian sandstones intercalate with playa lake muds in a delta setting quantitative analysis of the diagenetic mineral phases occurring in all main depositional facies eolian fluvial playa lake was carried out on more than 200 samples from 21 wells with the authigenic mineral composition of an additional 500 samples being evaluated qualitatively the integration of petrographical observations with log data and core descriptions reveals that cement distribution abundance is not dominantly driven by depositional facies nor are reservoir properties early pore filling dolomite cement can be as high as 40 and represents the main control on reservoir properties detailed analysis of its spatial distribution shows it to be distinctly related to mudstone proximity and mudstone sandstone m s ratio sandstones occurring as thin beds in mudstone rich depositional sequences high m s ratio typically exhibit strong pervasive carbonate cement regardless of sedimentary facies in contrast sandstones forming thick beds in mudstone poor sequences low m s ratio are commonly free low in dolomite cement our results demonstrate for the first time that reservoir quality in the rotliegend sandstones in the delta setting of the netherlands is primarily controlled by early dolomite cement the latter is most developed in areas with high 70 vertical m s ratio where it may be a devastating factor for reservoir quality best reservoir sandstones should be expected where the depositional stacking pattern is poor in shaly deposits playa lake and distal sheet flood sediments such as in the southern south eastern part of the studied area

the 12 may 2008 mw 7 9 wenchuan china earthquake macroseismic intensity assessment using the ems 98 and esi 2007 scales and their correlation with the geological structure the wenchuan earthquake of 12 may 2008 in sichuan province china can be classified as a large scale event based on the tectonic structures that triggered the earthquake and the effects caused on the human structural and natural environment this paper presents the geotectonic and seismotectonic regime of the earthquake affected region on the basis of field data obtained along the seismic fault zone and provides 1 an estimation of the intensity values according to the ems 98 and the esi 2007 scales and the determination of their large scale geographical distribution along the causative tectonic structure 2 an interpretation of the intensity distribution according to the seismotectonic geodynamic and geotechnical framework and 3 a comparison between two different intensity scales the ems 98 which is essentially based on the effects on the built environment and the esi 2007 which is based on earthquake environmental effects the application of both ems 98 and esi 2007 and the comparative review and evaluation of the results indicate that the estimated values of the ems 98 and the esi 2007 were similar this suggests that both scales can be useful and reliable tools for seismic hazard estimation

observations of a nonmigrating component of the semidiurnal tide over antarctica 1 data obtained from the mf radars situated at davis syowa and rothera in antarctica are used to detect a nonmigrating component of the semidiurnal tide in the mesosphere and lower thermosphere these radars are at similar latitudes and so share a common migrating tidal component by fitting semidiurnal tide vectors to each stations data and performing subtractions of these vectors for pairs of stations the migrating component can be removed and the difference between the nonmigrating components revealed non zero differences in the summer months december to march indicate the presence of a significant nonmigrating component modeling studies and observations at other sites suggest that it is most likely the westward propagating wavenumber 1 nonmigrating component that is contributing to the semidiurnal tide the data presented here are found to be consistent with this hypothesis a climatology of this nonmigrating component is presented and discussed comparisons with the global scale wave model suggest that latent heat release is not a significant forcing mechanism at these heights and latitudes

on modeling migrating solar tides recent updates and extensions to a steady state two dimensional linearized model of global scale atmospheric waves have facilitated improved calculations of the subset of those waves which are subharmonics of a solar day and propagate with the apparent motion of the sun the model improvements are briefly described and some updated predictions of the migrating solar diurnal component are highlighted the latter represent the first numerical modeling effort to examine the seasonal variability of the migrating diurnal harmonic as it propagates into the mesosphere and lower thermosphere

observed coupling of the mesosphere inversion layer to the thermal tidal structure rayleigh lidar observations of mesosphere temperature profiles obtained from 40 to 100 km from logan utah 41 7 111 8 w altitude 1 9 km over 10 nights in late february 1995 revealed an interesting development between 60 to 75 km of a winter mesosphere inversion layer with an amplitude of 20 30 k and a downward phase progression of 1 km hr the data also showed two altitude regions exhibiting significant cooling of 10 30 k in extent these were located below and above the peak of the inversion layer respectively at altitudes of 50 55 km and 70 80 km when these results were compared with the predictions of a global wave scale model gswm the observed thermal mesosphere structure is similar to the computed composite tidal structure based upon the semi diurnal and diurnal tides with the exception that observed amplitudes of heating and cooling are 10x larger than predicted gswm values we suggest that these events over utah are caused through a localized mechanism involving the coupling of gravity waves to the mesopause tidal structure

lunar tidal winds in the upper atmosphere over jakarta 1 winds have been measured at heights from 70 to 120 km by means of a meteor wind radar near jakarta 6 4s 106 7e from 1993 to 1997 these data have been analysed for the lunar semidiurnal tide using a least squares fitting method generally lunar tidal amplitudes in the winds are about 2 m s 1 though the northward wind amplitude reaches 6 m s 1 in southern summer variations with height and season are shown and compared with the global scale wave model gswm often the agreement with the model is good but there is a difference in phase of the eastward wind in southern winter the gswm predicts a more rapid increase in northward wind magnitude with height than is observed year to year changes are examined for different seasons and these reveal sometimes consistent results and sometimes a variation in phase from year to year often the phase relations between eastward and northward winds at jakarta are more characteristic of a northern hemisphere tide as predicted by classical tidal theory particularly in southern spring and summer

estimation of the equivalent rayleigh friction in mesosphere lower thermosphere region from the migrating diurnal tides observed by timed 1 we use thermosphere ionosphere mesosphere energetics and dynamics timed global temperature and wind data from 2002 to 2007 to investigate the damping of the diurnal tide horizontal winds are measured by tidi and are calculated from saber temperature measurements the determination of tidal winds from saber temperature depends on the damping and therefore the discrepancy between tidi and saber determinations of the wind tides can be used to calculate the tidal damping this damping is approximated here by an equivalent rayleigh friction erf and it is adjusted to minimize the difference in winds derived from saber and tidi data the results show that during some periods the erf coefficient can be very large over narrow vertical regions of about 5 km 10 5 s 1 in low latitudes and about 10 4 s 1 in midlatitudes the magnitude and shape of the vertical profiles change with latitude and season the peak in the vertical profile of erf is larger and located at a higher altitude in summer than in winter and the erf coefficients at 40 are stronger than at 20 in both hemispheres the erf deduced in this study without a priori assumption about the mechanism of the damping shows a seasonal variation that is clearly consistent with the seasonal variation of the zonal mean wind the maximum erf generally coincides with the altitudes of strongest wind reversal in the mesopause region

earthquake environmental effects in colombia during the past 35 years inqua scale project in this work we present the results of applying the inqua intensity scale to the analysis of the environmental effects of 12 moderate to large earthquakes with moment magnitudes m w in the range 5 6 8 1 that shook colombia between 1970 and 2004 these earthquakes were selected following consideration of their depths magnitudes and relevance of effects during shaking after analysis of shaking effects we found that earthquakes in colombia could be assigned inqua intensities between 6 and 11 for a subgroup of seven earthquakes we found a positive correlation between inqua intensities and m w defined by a best fit linear trend with a correlation coefficient of 0 7 and a positive correlation between inqua intensities and modified mercalli intensities with a correlation coefficient of 0 6 the inqua scale allowed us to compare local earthquakes with other earthquakes worldwide and to analyze each earthquake to better understand the ground response in colombia to the shaking during shallow earthquakes we conclude that in general the inqua scale provides a good estimate of intensity that may complement other measures of intensity

novel development in fluorescence microscopy of complex organic mixtures application in petroleum geochemistry abstract new data on the spectral fluorescence properties of complex organic mixtures derived from organic rich sediments and from fossil fuels are presented both the spectral ranges of the bitumen fractions including extractable hydrocarbons and polar compounds and the factors governing the spectral characteristics of complex organic mixtures are established the data provide rapid means of determining qualitatively an abundance or low concentration of saturates of highly alkylated aromatics and of condensed aromatic systems in such entities as extractable organic matter kerogen migrated hydrocarbons and liptinite macerals the implication of the data to petroleum geochemistry is discussed

observations of the quasi 2 day wave from the high resolution doppler imager on uars a strong westward traveling oscillation with a period of 2 days and zonal wave number 3 is observed in the mesospheric and lower thermospheric winds from the high resolution doppler imager on the upper atmosphere research satellite the important events happen in january july and september october of which the occurrence in january is the strongest with an amplitude over 60ms 1 detailed analyses for the periods of january 1992 and january 1993 reveal a cause and effect relationship in the wave developing process at 95km the global structures of the wave amplitude and phase are also presented

short term variability in the migrating diurnal tide caused by interactions with the quasi 2 day wave 1 the migrating diurnal tide is one of the dominant dynamical features in the low latitudes of the earth s mesosphere and lower thermosphere mlt region representing the atmospheric response to the largest component of solar forcing ground based observations of the tide have resolved short term variations attributed to nonlinear interactions between the tide and planetary waves that are also in the region using the ncar thermosphere ionosphere mesosphere electrodynamics general circulation model time gcm we simulate a quasi 2 day wave qtdw event under late january conditions in this case sideband sum and difference child waves are resolved indicating that a nonlinear interaction is occurring between the qtdw and the tide the migrating diurnal tide in the mlt displays local amplitude decreases of 20 40 as well as a shortening of vertical wavelength by roughly 4 km examining the physical mechanisms driving the interaction nonlinear advection is found to result in amplification of the tide in some regions and damping in others manifesting as increased smoothing of the tidal structure when the qtdw is present in the mlt additionally the qtdw also enhances the easterly summer mean wind jet that can also account for changes in tidal amplitude and vertical wavelength we find that qtdw induced background atmosphere changes in time gcm can drive tidal variability at levels greater than nonlinear advection a possibility not previously considered

diurnal variation of gravity wave momentum flux and its forcing on the diurnal tide 1 the diurnal variation of gravity wave gw momentum flux is derived from the 5 years of meteor radar wind measurements at maui hawaii the amplitude and phase relationships between the gw forcing and the diurnal tide are analyzed by calculating their equivalent rayleigh frictions the results show that the gw momentum flux is clearly modulated by the diurnal tide the forcing from the momentum flux convergence has strong effects on both the amplitude and phase of the diurnal tide they can reach 80 ms 1 day 1 for the amplitude and 15 h day 1 for the phase the gw forcing tends to increase the diurnal tide amplitude above 90 km but has a small damping effect below 90 km it tends to increase the phase of the diurnal tide throughout all altitudes seasonal variations of the gw forcing exist which result in differences in their effects on the diurnal tide the magnitudes of the forcing are in agreement with recent results from satellite observations but are much larger than values used in general circulation models this work also demonstrates that meteor radar measurements can provide a valuable data set for the study of gw tide interactions

reply to comment on a comparison of atmospheric tides inferred from observations at the mesopause during aloha 93 with the model predictions of the time gcm by j h hecht et al

the 6 5 day wave and its seasonal variability in the middle and upper atmosphere 1 the zonal wave number 1 planetary wave of period near 6 5 days is a robust feature in the mesosphere and lower thermosphere mlt region with prominent seasonal variability as revealed by ground based and satellite observations this wave and its seasonal variability are well reproduced in a recent one model year run of the national center for atmospheric research thermosphere ionosphere mesosphere electrodynamics general circulation model time gcm with its lower boundary specified according to the national centers for environmental prediction analysis year 1993 wavelet analysis of the model output shows that in the mlt region the wave maximizes before and after the equinoxes and minimizes at solstices the wave amplitudes at the equinoxes are smaller than the peaks before and after but are still larger than the wave amplitudes at solstices however at the lower boundary near 30 km the wave peaks are predominantly between fall and the following spring by examining the episodes of maximum and minimum wave amplitude and by conducting additional control experiments using the time gcm the structure of this planetary wave and the factors determining the wave characteristics and seasonal variability are studied in detail it is found that the wave source mean wind structure instability and the critical layers of the wave can all affect the wave response in the mlt region and can have a strong seasonal dependence before and after equinox the wave follows the waveguide and propagates from the stratosphere to the summer mesosphere mesopause where it may amplify due to baroclinic barotropic instability such instability is usually absent from the equinoctial atmosphere so that there is no wave amplification at equinox at solstice the wave decays significantly when propagating away from its winter source due to the strong eastward winter stratospheric jet in the summer side the westward jet is also strong and the meridional and vertical extension of the critical layer of the wave is large enough to enclose the instability in the summer mesosphere mesopause at middle to high latitudes the wave is thus reflected away and prevented from reaching and amplifying at the unstable region the seasonal variation of the quasi two day wave which has zonal phase speed similar to the 6 5 day wave is also studied using similar diagnostics it is further shown that within certain seasonal window periods the variability in the mlt especially the summer mlt may closely track the lower atmospheric variability associated with these waves

the meridional wind component of the thermospheric tide observed by windii on uars thermospheric meridional winds measured by the wind imaging interferometer windii on the upper atmosphere research satellite uars are analyzed for migrating solar tides for march april 1993 tidal signatures are extracted by zonally averaging and binning the data in equally spaced intervals of local time latitude and altitude an examination of the binned data reveals vertically propagating tides in the lower thermosphere with the diurnal tide dominating at low latitudes above 120 km evidence of vertical propagation ceases and the vertical gradients are significantly reduced in regions where both daytime and nighttime data are available fourier decomposition of the binned winds is used to extract the diurnal component of the tide this analysis reveals that the propagating diurnal tide attains a maximum amplitude of 65 m s at 20 n and 20 s at 95 km and exhibits a vertical wavelength of about 25 km

future trends in paleoseismology integrated study of the seismic landscape as a vital tool in seismic hazard analyses this paper forms the introduction to this special issue of tectonophysics devoted to selected scientific research presented during events sponsored by the inqua subcommission on paleoseismicity in the past few years in this note we summarize the contents of the contributed papers and use the issues they raise to review the state of the art in paleoseismology from a quaternary geology perspective in our opinion the evolution of paleoseismological studies in the past decade clearly demonstrates that in order to properly understand the seismic potential of a region and to assess the associated hazards broad based multidisciplinary studies are necessary to take full advantage from the geological evidence of past earthquakes a major challenge in future paleoseismic research is to build detailed empirical relations between various categories of coseismic effects in the natural environment and earthquake magnitude intensity these relations should be compiled in a way that is fully representative of the wide variety of natural environments on earth in terms of climatic settings quaternary tectonic evolution rheological parameters of the seismogenic crust and stress environment for instance available data indicate that between earthquake magnitude and surface faulting parameters different scaling laws exist and they are a function of the local geodynamic setting including style of faulting typical focal depths heat flow in this regard we discuss in some detail the concept of seismic landscape which provides the necessary background for developing paleoseismological research strategies the large amount of paleoseismological data collected in recent years shows that each earthquake source creates a signature on the geology and the geomorphology of an area that is unequivocally related with the order of magnitude of its earthquake potential this signature is defined as the seismic landscape of the area e g serva l vittori e ferreli l michetti a m 1997 geology and seismic hazard in grellet b mohammadioun b hays w eds proceedings of the second france united states workshop on earthquake hazard assessment in intraplate regions central and eastern united states and western europe october 16 1995 nice france 20 24 ouest editions nantes france michetti a m hancock p l 1997 paleoseismology understanding past earthquakes using quaternary geology

interannual variations of the quasi 16 day oscillation in the polar summer mesospheric temperature nighttime measurements of the hydroxyl meinel 4 2 rotational band have been used to infer the mesospheric temperature over scandinavia from june to august during the years 1992 1995 while the nightly averaged temperatures show a statistically significant quasi 16 day oscillation in the 1992 and 1994 summer data none is observed during 1993 and 1995 when present the period amplitude and temporal behavior of this oscillation agree with both model predictions and previous wind measurements of the 1 3 rossby normal mode in the summer mesosphere thus this temperature oscillation appears to correspond to the thermal signature of the 16 day rossby mode its appearance in the summer mesosphere is shown to occur when the oscillating zonal flows in the upper stratosphere near the equator are in an eastward phase while it appears to be blocked during the westward phases this correspondence of the 16 day wave in the summer mesosphere with the eastward equatorial wind would favor the explanation that it is generated in the winter hemisphere and propagates vertically and toward the summer pole following the westerly mean winds

first u s china joint ground based fabry perot interferometer observations of longitudinal variations in the thermospheric winds for the first time three fabry perot interferometers from the u s boulder 40 degrees n 105 degrees w 49 degrees n magnetic latitude mlat and china xinglong 40 degrees n 115 degrees e 34 degrees n mlat kelan 39 degrees n 112 degrees e 33 degrees n mlat were used to examine the longitudinal variations in the thermospheric winds due to the geomagnetic latitude differences between the american and asian sectors during a case of quiet geomagnetic condition the meridional winds were very similar at the u s and chinese stations the meridional winds at boulder reached most equatorward winds after midnight whereas in china the largest equatorward winds were found near midnight the boulder zonal winds turned westward earlier in the morning hours and had larger diurnal variations because of its higher magnetic latitude during the case of low geomagnetic activity kp similar to 2 the meridional winds were still similar in the u s and in china boulder zonal winds had much larger diurnal variation compared to the quiet condition kp similar to 1 thermosphere ionosphere electrodynamics general circulation model simulations show a very good agreement with observation for the meridional winds the simulated zonal winds exhibit noticeable differences with observations but the general tendencies in longitudinal variations with a larger diurnal variation near the auroral oval are correct simulations showed that the ion drift is not directly responsible for the longitudinal variations in the winds the pressure gradient had more direct effect on the longitudinal changes in the winds the simulation results also showed larger diurnal variations at higher geomagnetic latitudes due to the auroral oval heating nonmigrating tides were not observed in the two cases in october 2012

julia radar studies of electric fields in the equatorial electrojet first results from the julia radar at jicamarca are presented these include coherent scatter observations of the equatorial electrojet and of 150 km echoes interferometry is used to measure the zonal drift rate of kilometer scale waves in the electrojet as functions of altitude a technique for estimating the background zonal electric field from the interferometry data is described the electric field estimates can be calibrated against the doppler speed of the 150 km echoes when the latter are present the kilometer scale wave drifts sometimes exhibit large amplitude periodic height variations with vertical wavelengths of about 10 km these signatures are reminiscent of the wind profiles measured with chemical release techniques in the lower thermosphere during the guara campaign

earthquake ground effects and intensity of the 16 april 2016 mw 7 8 pedernales ecuador earthquake implications for the source characterization of large subduction earthquakes

mesosphere inversion layers and stratosphere temperature enhancements 1 it has been known for at least 30 years that vertically narrow thermal layers form within the middle atmosphere two types of temperature enhancements the low latitude to midlatitude mesosphere inversion layer mil and the high latitude winter stratosphere temperature enhancement ste have both received much attention within the atmospheric science community because of their unexplained formation mechanisms and potential impacts on the middle atmosphere global circulation numerous experimental numerical and theoretical studies have attempted to explain certain aspects of these respective thermal layers but no one theory consistently and satisfactorily describes all the features observed we present a review of the literature and explicitly propose a classification scheme based on the different formation mechanisms suspected to cause these events for the mil we demonstrate that there are two subtypes the first one is tidally driven and tends to occur above 85 km this mil originates from large amplitude tidal waves propagating into the mesosphere and their subsequent nonlinear interactions with gravity waves which can often create the appearance of a double mil separated by approximately one vertical tidal wavelength 25 km the other subtype of mil is formed by a climatological planetary wave dissipation mechanism that occurs at a zero wind line the dissipation of the planetary wave tends to generate a mesoscale 1000 km inversion layer in the range of 65 80 km these two formation mechanisms explain a host of observed characteristics including the reason behind the downward progression of some mils and not others the different climatological nature of the two forms of mil events and the relative scarcity of mil observations at high latitudes the ste is believed to be generated by an altogether different process namely the nonlinear interaction between the polar vortex and planetary waves aleutian high the induced temperatures typically peak around 40 km and often exceed 300 k generating what appears to be a low hot stratopause when vertical temperature profiles are combined with synoptic analyses one observes that the ste is the consequence of high latitude vortex interactions creating a baroclinic atmosphere i e a downward adiabatic compression induced by an ageostropic flow we summarize the details of the relationship between this feature and sudden stratospheric warmings as well as the potential for in situ gravity wave generation we close with a review of currently unexplained mil ste features and offer new directions for future middle atmosphere thermal layer research

on the sensitivity of infrasonic traveltimes in the equatorial region to the atmospheric tides 1 in comparison to the lower atmosphere where comprehensive global atmospheric specifications are commonplace the ability to perform routine global measurements of the properties of the atmosphere above the stratopause continues to be an active area of scientific research in this paper we revisit the use of infrasound as a remote sensing technique for horizontal winds in the upper atmosphere to use infrasound to monitor the winds in the upper atmosphere a sufficiently strong and persistent infrasound source is required in addition because of the highly attenuating nature of the thermosphere the signals used must have low enough frequency content to survive in this paper impulsive signals from the tungurahua volcano in ecuador are used this volcano has gone through periods of intense activity during which impulsive signals of dominant periods between 3 and 5 s are emitted depending on the atmospheric conditions stratospheric mesospheric and thermospheric arrivals are observed it is found that the traveltimes of the thermospheric arrivals exhibit a coherent variability with periods equal to those of the tidal harmonics as such these observations suggest a means of passive atmospheric remote sensing that can be utilized in conjunction with other techniques to routinely measure the state of the upper atmosphere

development of n w europe s southern permian gas basin summary the southern permian basin contains over 4 1 10 12 m 3 of recoverable non associated gas most of which is found in early permian rotliegend sandstones the most important source of this gas is carboniferous coal deposited in a proto tethys foredeep basin where the coals were overlain by rotliegend desert sands and by late permian zechstein halite the scene was set for creating important reservoirs for gas deformation of the reservoir and seal to create a trap and the generation and migration of carboniferous gas resulted from the structural history of the area which was shaped in part by underlying crustal blocks and zones of crustal weakness much of this history was related to events most clearly expressed beyond the limits of n w europe in the north atlantic and tethys 1 e w tension which gave rise to the oblique slip induced subsidence of many sub basins within the southern permian basin caused the consecutive creation of the viking central graben system and rockall trough and ended with the crustal spreading of the atlantic ocean and 2 the early mesozoic opening of tethys its cretaceous closure and ensuing alpine orogeny which induced inversion in many areas of the southern permian basin that are now gas bearing

formation of carboniferous pb zn and barite mineralization from basin derived fluids nova scotia canada lead zinc and barite deposits in central nova scotia generally occur at the tournaisian visean mississippian clastic carbonate evaporite disconformity overlying cambrian to devonian metasedimentary and granitic rocks the deposits are located at the southern margin of the 10 km deep carboniferous maritimes fundy magdalen basin fluid inclusion homogenization temperatures of ore stage to postore minerals range from 230 degrees to 130 degrees c and fluid salinity is or 24 equiv wt percent nacl a mineralization age of ca 300 to 330 ma is suggested by 1 fission track dates on zircon from clastic host rock at gays river 2 k ar dates on clays from altered clastic rock in close proximity to mineralization and 3 rb sr data on illite from samples collected over a 10 m section of tournaisian sandstone far away from mineralization lead and strontium isotope data indicate that tournaisian rock of the horton group could have been a source at ca 300 ma of lead and radiogenic strontium in the ore stage minerals at the larger deposits visean carbonate carbon and sulfate were the dominant sources of carbon and sulfur respectively hydrogen and oxygen isotope data suggest that the mineralizing fluids were basinal brines nonbiogenic sulfate reduction at the deposits is the likely sulfide precipitation mechanism the ore forming fluids may have originated at a 5 km depth under visean evaporites in the magdalen basin and migrated rapidly through tournaisian clastic rocks and the immediately overlying pembroke breccia to the basin margins a pulse of regional tectonism may have set off at least one massive hydrofracturing compaction driven fluid expulsion event by about 300 ma

environmental effects from five historical earthquakes in southern apennines italy and macroseismic intensity assessment contribution to inqua eee scale project abstract this paper aims at substantiating the basic postulate of the recent earthquake environmental effects eee scale proposed by the international union for quaternary research inqua that primary and secondary environmental effects of earthquakes provide invaluable information on the earthquake size and intensity field complementing but also independently testing the results of the traditional damage based macroseismic scales the eee scale is applied to five disastrous earthquakes which occurred in southern italy since the end of the xvii century for each considered earthquake the available macroseismic data have been reviewed and integrated through an updated interpretation of the original texts the cataloguing and analysis of the seismically induced environmental effects has provided a a more detailed picture of the macroseismic fields b the chance to test the scaling of the eee scale with the mcs and msk macroseismic scales confirming its good fit with the msk mm c i0 estimates based on eee scale in good agreement with i0 assessments derived from mcs msk scales d further constrains for the new version of the eee scale e useful data for seismic zonation these results have confirmed once more the essential role of eees in the process of seismic hazard assessment and risk reduction

evidence against natural deformation of fluid inclusions in diagenetic quartz abstract this paper describes evidence for and against burial induced deformation of fluid inclusions in diagenetic quartz fluid inclusions in diagenetic minerals are prone to non elastic deformation stretching or leakage if subjected to progressive burial in a sedimentary basin if they deform they cannot record mineral growth conditions correctly a correlation between homogenization temperature and depth may be interpreted as indicating wholesale leakage or stretching experimental work and theoretical studies suggest that heating 200 c higher than the homogenization temperature is required to produce significant deformation but it may not be possible to extend the results to natural conditions the experiments further predict a correlation between homogenization temperature and inclusion size in a sample of inclusions that have undergone natural deformation this is not observed in natural examples but the absence of a correlation is not proof that leakage has not occurred several features of inclusion data in quartz cements do however argue against stretching or leakage homogenization temperatures commonly show narrow distributions and are compatible with independent data such as illite potassium argon ages and petrography different generations of inclusions in a single sample set also retain homogenization temperature distributions compatible with their sequential origin taken as a whole the body of evidence argues against widespread stretching or leakage of fluid inclusions in diagenetic quartz

the application of fluid inclusions to migration of oil and diagenesis in petroleum reservoirs abstract fluid inclusions can be used to interpret thermal history and petroleum maturation and migration relative to burial history temperature pressure and composition data collected from fluid inclusions are used to determine the environment of diagenesis and the timing of cementation and migration cements in petroleum reservoirs contain both oil and aqueous fluid inclusions fluorescence spectroscopy is used to identify oil inclusions and to determine the maturity of entrapped oil the lifetime of fluorescence induced by a pulsed laser is related to the api gravity of entrapped oil interpretation of fluid inclusion data depends on knowing the origin of fluid inclusions and the probability that they survive in the burial environment those aspects of fluid inclusion study are investigated by synthesizing oil and aqueous inclusions in calcite crystals in laboratory experiments examples of how fluid inclusions are used to determine the physico chemical environments of diagenesis in petroleum reservoirs and the timing of cementation and migration are given for the wealden basin england the mishrif formation dubai the smackover formation gulf coast u s a and jurassic sandstones offshore norway in the wealden basin temperature data from fluid inclusions are used to determine that oil migration occurred in the cretaceous and that the reservoir rocks have been uplifted to varying degrees at a time after migration distribution of oil inclusions indicates that generation and migration of oil was principally in the western part of the basin the geochemistry of oil inclusions in calcite cements from the mishrif formation dubai are used to determine the type and maturity of entrapped oil temperature data from oil and water inclusions are used to relate reservoir diagenesis to burial history and the migration of oil in deep smackover reservoirs oil contains h 2 s the origin of the h 2 s is examined by study of fluid inclusions containing h 2 s in jurassic sandstones offshore norway fluid inclusion studies show that silica cementation is related to burial depth whereas a later calcite cementation originated from invasion of a hot fluid

momentum budget of the migrating diurnal tide in the whole atmosphere community climate model at vernal equinox 1 the momentum budget of the migrating diurnal tide dw1 at the vernal equinox is studied using the whole atmosphere community climate model version 4 waccm4 classical tidal theory provides an appropriate first order prediction of the dw1 structure while gravity wave gw forcing and advection are the two most dominant terms in the momentum equation that account for the discrepancies between classical tidal theory and the calculation based on the full primitive equations it differs from the conclusion by mclandress 2002a that the parameterized gw effect is substantially weaker than advection terms based on the canadian middle atmosphere model cmam in the region where dw1 maintains a large amplitude gw forcing in the wave breaking region always damps dw1 and advances its phase the linear advection largely determined by the latitudinal shear of the zonal mean zonal wind makes a dominant contribution to the phase change of dw1 in the zonal wind compared to the gw forcing and nonlinear advection however nonlinear advection is more important than gw forcing and linear advection in modulating the amplitude and phase of dw1 in the meridional wind the dw1 amplitudes in temperature and winds are smaller than the timed observations suggesting that gw forcing is overestimated in the waccm4 and results in a large damping of dw1

observations of the diurnal tide from space abstract this study presents a climatology of mesospheric and lower thermospheric diurnal tidal winds obtained with the high resolution doppler imager hrdi on the upper atmosphere research satellite uars the observations reveal that although tidal structures are present at all times like the prevailing zonal winds they exhibit significant semiannual as well as other shorter term variations in amplitude results are presented for a period extending over more than one year from november 1991 to july 1993 the 1 1 diurnal tidal amplitude of the meridional component characterized by the value at an altitude of 90 km and a latitude of 22 ranges from a minimum at solstice of less than 20 m s 1 to an equinox maximum of over 70 m s 1 the vertical wavelength and phase of the tide show only slight variations throughout the year with a suggestion of semiannual variations in both

momentum budget of the migrating diurnal tide in the mesosphere and lower thermosphere 1 the leading terms of the momentum budget of the migrating diurnal tide are diagnosed from temperatures and geopotential height provided by thermosphere ionosphere mesosphere energetics and dynamics timed sounding of the atmosphere using broadband emission radiometry saber and the horizontal wind vector provided by timed doppler interferometer tidi the wave drag upon the tide is inferred as a residual of the classical and linear advective terms in the zonal and meridional momentum equations between 85 and 100 km the migrating diurnal tide is generally far from the classical description of chapman and lindzen 1970 the leading nonclassical terms are the meridional advection of zonally averaged momentum and wave drag effects encapsulated in the momentum residuals the magnitudes of the momentum residuals range between 50 and 150 m s 1 d 1 for the zonal component and 100 250 m s 1 d 1 for the meridional component the zonal momentum residual is generally in quadrature with the zonal wind tide while the meridional momentum residual is in antiphase with the meridional wind above 95 km winds and temperatures exhibit maximum amplitudes during the vernal equinox season but only a minor reduction in wave damping is observed our results suggest that rayleigh damping is inadequate to describe the relationship between the tide and the forces acting upon it

earthquake hazard and the environmental seismic intensity esi scale the main objective of this paper was to introduce the environmental seismic intensity scale esi a new scale developed and tested by an interdisciplinary group of scientists geologists geophysicists and seismologists in the frame of the international union for quaternary research inqua activities to the widest community of earth scientists and engineers dealing with seismic hazard assessment this scale defines earthquake intensity by taking into consideration the occurrence size and areal distribution of earthquake environmental effects eee including surface faulting tectonic uplift and subsidence landslides rock falls liquefaction ground collapse and tsunami waves indeed eees can significantly improve the evaluation of seismic intensity which still remains a critical parameter for a realistic seismic hazard assessment allowing to compare historical and modern earthquakes moreover as shown by recent moderate to large earthquakes geological effects often cause severe damage therefore their consideration in the earthquake risk scenario is crucial for all stakeholders especially urban planners geotechnical and structural engineers hazard analysts civil protection agencies and insurance companies the paper describes background and construction principles of the scale and presents some case studies in different continents and tectonic settings to illustrate its relevant benefits esi is normally used together with traditional intensity scales which unfortunately tend to saturate in the highest degrees in this case and in unpopulated areas esi offers a unique way for assessing a reliable earthquake intensity finally yet importantly the esi scale also provides a very convenient guideline for the survey of eees in earthquake stricken areas ensuring they are catalogued in a complete and homogeneous manner

nightglow zenith emission rate variations in o 1 s at low latitudes from wind imaging interferometer windii observations volume emission rate data of the o 1 s nightglow layer measured by the wind imaging interferometer windii aboard the upper atmosphere research satellite uars are vertically integrated to give equivalent zenith column emission rates the data are restricted to tropical latitudes and categorized according to season the migrating tidal signature is extracted by plotting zonally averaged data as a function of local time the main features are a premidnight maximum at the equator during equinox intervals and a midnight maximum at 20 n and s the two equinoxes are not equivalent nor is the behavior identical in the two hemispheres winter periods show little or no well defined tidal signature longitudinal variations at fixed local time were also studied these variations are larger than the tidal signature and are geographically random showing no consistent identification with land masses some of these variations could be of planetary scale while others are probably long wavelength gravity waves but in any case they were seen to extend over 10 of latitude at least zenithal emission rate measurements exceeding 500 r occurred at the coincidence of these longitudinal wave structures and the tidal maxima the suggestion is put forward that much of the perceived tidal variability in the tropical lower thermosphere may be explained by such wave tide superpositions