a new multiscale model for the madden julian oscillation abstract a multiscale model of the mjo is developed here that accounts in a simplified fashion for both the upscale transfer from synoptic to planetary scales of momentum and temperature from wave trains of thermally driven equatorial synoptic scale circulations in a moving convective envelope as well as direct mean heating on planetary scales this model involves idealized thermally driven congestus synoptic scale fluctuations in the eastern part of the moving wave envelope and convective superclusters in the western part of the envelope the model self consistently reproduces qualitatively many of the detailed structural features of the planetary circulation in the observations of the mjo including the vertical structure in both the westerly onset region and the strong westerly wind burst region as well as the horizontal quadrupole planetary vortex structure the westerly midlevel inflow in the strong westerly region and the quadrupole vortex are largely produced in the model by the upscale transpor

strain accumulation in western united states this review is principally concerned with recent geodetic strain measure ments in western united states undertaken by the us geological survey as part of the earthquake studies program and as a consequence is heavily biased toward the author s own publications most of the publications reporting crustal strain measurements in western united states prior to about 1968 have been compiled in one volume national geodetic survey 1973 and more recent work with complete bibliographies is summarized in three successive quadrennial reports to the international union of geodesy and geophysics meade 1971 savage 1975 thatcher 1979b the following conventions are employed in this paper strain a dimensionless quantity is reported in units of 10 6 extension is taken as positive to distinguish between engineering and tensor shear strain we denote the former by y and quote the units as j lrad whereas the latter is denoted by e and given the units of j lstrain uncertainties in all cases are quoted as one standard deviation at the present time geodetic techniques furnish the only reliable measure of strain accumulation in the seismic regions of the world the superiority of geodetic techniques derives principally from the long baseline of the measurements difficulties in coupling fiducial marks to the earth have generally made short baseline measurements of strain accumulation questionable wyatt 1982 however long baselines introduce the dis advantage that the measured strain is not closely localized the current technique of measuring strain accumulation involves the

geodetically determined strain across the southern end of the tonga kermadec hikurangi subduction zone summary a method of simultaneous reduction is presented for determining strain rates from multiple triangulation surveys where common triangulation stations have been used but the angles of the old survey have not necessarily been reobserved this method is applied to triangulation in the northern south island at the southern end of the tonga kermadec hikurangi subduction zone from a profile of shear strain across the indian pacific plate boundary the displacement of the indian plate relative to the pacific is calculated to be 54 9 mm yr at an azimuth of 84 f lo in remarkable agreement with the motion predicted by global plate tectonic models most of this motion occurs within a 15okm wide zone bounded on the east by the hikurangi trough within this zone the motion is partitioned near the hikurangi trough no slip is occurring at the upper surface of the subducting pacific plate the subduction thrust and motion is predominantly thrusting normal to the trough axis to the west is a region of predominantly dextral strike slip faulting this pattern is consistent with fitch s model of oblique subduction to the south of the profile a change is observed in the azimuth of the faulting along a line which marks the southern extent of the subduction slab indicating the end of the partitioned motion

multiscale organization of convection simulated with explicit cloud processes on an aquaplanet abstract this study investigated the multiscale organization of tropical convection on an aquaplanet in a model experiment with a horizontal mesh size of 3 5 km for a 10 day simulation and 7 km for a 40 day simulation the numerical experiment used the nonhydrostatic icosahedral atmospheric model nicam with explicit cloud physics the simulation realistically reproduced multiscale cloud systems eastward propagating super cloud clusters sccs contained westward propagating cloud clusters ccs sccs ccs had zonal sizes of several thousand hundred kilometers typical propagation speed was 17 10 m s 1 smaller convective structures such as mesoscale cloud systems mcs of o 10 km and cloud scale elements 16 km of o 100 km area was also reproduced planetary scale equatorial waves with wavelengths of 10 000 and 40 000 km had a major influence on the eastward propagation of the simulated scc destabilization east of the

view angle dependence of cloud optical thicknesses retrieved by moderate resolution imaging spectroradiometer modis 1 this study examines whether cloud inhomogeneity influences the view angle dependence of modis cloud optical thickness retrieval results the degree of cloud inhomogeneity is characterized through the local gradient in 11 m brightness temperature the analysis of liquid phase clouds in a 1 year long global data set of collection 4 modis data reveals that while optical thickness retrievals give remarkably consistent results for all view directions if clouds are homogeneous they give much higher values for oblique views than for overhead views if clouds are inhomogeneous and the sun is fairly oblique the mean optical thickness retrieved for the most inhomogeneous third of cloudy pixels is more than 40 higher for oblique views than for overhead views if the solar zenith angle exceeds 60 after considering a variety of possible scenarios the paper concludes that the most likely reason for the increase lies in three dimensional radiative interactions that are not considered in current one dimensional retrieval algorithms namely the radiative effect of cloud sides viewed at oblique angles seems to contribute most to the enhanced optical thickness values the results presented here will help understand and estimate cloud retrieval uncertainties related to cloud inhomogeneity and may eventually help correct for the observed view angle dependent biases

observations of three dimensional radiative effects that influence modis cloud optical thickness retrievals abstract when cloud properties are retrieved from satellite observations current calculations apply one dimensional 1d theory to the three dimensional 3d world they consider only vertical processes and ignore horizontal interactions this paper proposes a novel approach that estimates 3d effects in cloud optical thickness retrievals the proposed method combines visible and thermal infrared images to see whether 3d radiative effects make clouds appear asymmetric that is whether cloud surfaces tilted toward the sun are systematically brighter than surfaces tilted away from it the observed asymmetries are then used to estimate 3d effects for 1 km size pixels as well as 50 km size areas initial results obtained for moderate resolution imaging spectroradiometer modis images reveal that 3d effects cause abundant uncertainties in the 1 km resolution 1d retrievals averaging over 50 km by 50 km areas greatly reduces the errors but does not remove them completely conservative estimates show that the m

mean deformation tensor and mean deformation ellipse of an excavated tunnel section abstract terzaghi based on graphical methods introduced the concept of the deformation ellipse as a tool to understand and visualize the deformation of tunnel sections after their excavation originally assumed as perfect circles the deformation ellipse gave the opportunity to pass from a set of displacement data expressing the convergence of a tunnel section in a complicated and occasionally mutually inconsistent way to the concept of deformation of a circle to an ellipse and thereby to understand the pattern and the changes of the pattern of deformation of a tunnel during its excavation and search for the causes of this change nevertheless because of its graphic character and limitation in the available data this approach seems to have rarely been used in this paper we present analytical solutions for the mean tensor of deformation and of the mean deformation ellipse of a tunnel section regarded as a deforming pure mathematical curve this transformation of a circle to an ellipse corresponds to the strain due to re arrangement of stresses just after the section excavation and hence describes the deformation of the surrounding rockmass and of support independently of any stress focusing models and measurements this technique can be used for all types of geodetic and geotechnical monitoring data tape extensometer total station laser scanner etc measurements in tunnels and other underground excavations and its only requirements are a uniform plane strain conditions in each control section during and shortly after the underground excavation and b a nearly uniform distribution of observations along the tunnel section uncertainties in estimates permit to confirm whether the adopted model of a mean deformation ellipse is suitable to describe the deformed excavation section the robustness and value of this approach are highlighted in two case studies

deformation and failure of the tymfristos tunnel greece the tymfristos tunnel a 1 365m long road tunnel with an 11m section diameter was excavated through the highly tectonized low strength flysch formation of central greece about 1 year after the completion of the excavation in 1995 convergence of up to 20 followed by failure of the support system was recorded a 501m long segment in which the failure occurred was reexcavated based on a more detailed study of the ground conditions however this second phase was also followed by an up to 6 convergence the detailed geodetic study of the three dimensional kinematics of the support shell in relation time ring closure delays and support measures reveals an unusual time history of convergence occasionally continuing even after the ring closure and a nonuniform distortion of the lining furthermore uncontrolled deformation of certain weak sections propagated bidirectionally to adjacent previously stabilized sections producing a chain effect responsible for destabilization and resumed convergence

the organization of tropical convection by intraseasonal sea surface temperature anomalies the organization of convection by intraseasonal sea surface temperature sst anomalies is investigated to examine the role that atmosphere ocean coupling may play in the maintenance of the madden julian oscillation an atmospheric general circulation model with an ocean covered surface is used to investigate the response of tropical convection to idealized imposed intraseasonal sst anomalies and the sensitivity of this response to their propagation speed the convection is found to be organized on the spatial and temporal scales of the imposed sst anomalies and the location of the maximum in precipitation relative to the sst anomaly is in good agreement with observations and different from that for a stationary sst anomaly the magnitude of the precipitation anomalies increases with decreasing propagation speed of the sst anomalies the role of the free tropospheric humidity is crucial for determining the location and magnitude of the precipitation response

inference of marine stratus cloud optical depths from satellite measurements does 1d theory apply abstract the validity of plane parallel 1d radiative transfer theory for cloudy atmospheres is examined by directly comparing calculated and observed visible reflectances for one month of global area coverage advanced very high resolution radiometer satellite observations of marine stratus cloud layers off the coasts of california peru and angola marine stratus are an excellent testbed as they arguably are the closest to plane parallel found in nature optical depths in a 1d radiative transfer model are adjusted so that 1d model reflectances match those observed at nadir on a pixel by pixel basis the 1d cloud optical depth distributions are then used in the plane parallel model to generate reflectance distributions for different sun earth satellite viewing geometries these reflectance distributions are directly compared with the observations separate analyses are performed for overcast and broken cloud layers as identified by the spatial coherence method when 1d reflectances are directly compare

the potential for improved boundary layer cloud optical depth retrievals from the multiple directions of misr abstract the multiangle imaging spectroradiometer misr views the earth with nine cameras ranging from a 70 zenith angle viewing forward through nadir to 70 viewing aft misr does not have an operational cloud optical depth retrieval algorithm but previous research has hinted that solar reflection measured in multiple directions might improve cloud optical depth retrievals this study explores the optical depth information content of misr s multiple angles using a retrieval simulation approach hundreds of realistic boundary layer cloud fields are generated with large eddy simulation les models for stratocumulus small trade cumulus and land surface forced fair weather cumulus reflectances in misr directions are computed with three dimensional radiative transfer from the les cloud fields over an ocean surface and averaged to misr resolution and sampled at misr 275 m pixel spacing neural networks are trained to retrieve the mean and standard deviation of optical depth over different size pixel pa

the madden julian oscillation observed during the toga coare iop global view abstract during the toga coare intensive observing period november 1992 february 1993 two pronounced madden julian oscillation mjo events associated with super cloud clusters and westerly wind bursts were observed this paper presents a global view of the mjos including the origin of the super clusters in the indian ocean their migration into the maritime continent and the toga coare large scale soundings array lsa in the western equatorial pacific and their rapid decay over cold water of the eastern pacific the structure and evolution of the mjo are examined with emphasis on the coupling between large scale motion and convection because of differences in propagation speeds the positions of maximum zonal wind perturbations relative to deep convection undergo systematic changes during the travel of the mjo however the centers of deep convection always coincide with those of large scale ascent the super cloud cluster accompanies a wide area of warm air in the upper troposphere over the warm

a climatology of waves in the equatorial region abstract propagating anomalies of moisture and moist deep convection in the tropics are organized into a variety of large scale modes these include but are not limited to the so called intraseasonal oscillations convectively coupled waves similar to those predicted by shallow water theory on the equatorial beta plane and tropical depression type disturbances along with the annual and diurnal cycles these modes act and interact to control much of the variance of tropical convection analyses of 10 yr of outgoing longwave radiation olr and precipitable water pw data are carried out to develop comparative climatologies of these wavelike modes the analysis relaxes the commonly used cross equatorial symmetry constraints which allows study of the portions of the wavelike processes that are asymmetric across the equator mean background states are found for olr and for pw as functions of day of the year examination of anomalies together with the background reveals much about how the waves are affec

mesoscale motion fields associated with a slowly moving gate convective band abstract the structure of the convective band of 14 september in the dense gate observing array is determined using wind and thermodynamic data primarily from multiple aircraft penetrations which are well distributed in the vertical and in time the well defined mesoscale features in the line which are 10 40 km in scale quasi two dimensional and persist for several hours determine the distribution of the convective scale features which are 5 km or less in size three dimensional not generally detectable for more than one flight leg at the leading edge a 30 km zone of strong ascent is computed from two dimensional continuity here lifting of the ambient air creates a favorable environment not found elsewhere for deep cumulonimbus clouds to develop their updrafts are weak 2 4 m s 1 on the average behind the updraft zone below 3 4 km is a broad descent zone it corresponds to the stratiform rain area and has little convection and some drying at lower levels on the average the mass flux by

influence of subpixel scale cloud top structure on reflectances from overcast stratiform cloud layers abstract recent observational studies have shown that satellite retrievals of cloud optical depth based on plane parallel model theory suffer from systematic biases that depend on viewing geometry even when observations are restricted to overcast marine stratus layers arguably the closest to plane parallel in nature at moderate to low sun elevations the plane parallel model significantly overestimates the reflectance dependence on view angle in the forward scattering direction but shows a similar dependence in the backscattering direction theoretical simulations are performed that show that the likely cause for this discrepancy is because the plane parallel model assumption does not account for subpixel scale variations in cloud top height i e cloud bumps monte carlo simulations comparing 1d model radiances to radiances from overcast cloud fields with 1 cloud top height variations but constant cloud volume extinction 2 flat tops but horizontal variations in cloud volume extinction and 3 v

neural network retrieval of cloud parameters of inhomogeneous clouds from multispectral and multiscale radiance data feasibility study 1 in this paper we investigated the feasibility of retrieving cloud parameters of inhomogeneous and fractional clouds from simulated multispectral and multiscale radiometric data by using mapping neural networks a radiometric database prepared for neural network training consists of area averaged radiance data for two pixel scales i e 1 km 1 km and 0 25 km 0 25 km pixels respectively the cloud parameter retrieval assumes a vertically uniform inhomogeneous and fractional cloud defined with 6 parameters i e the mean and standard deviation of optical thickness the mean and standard deviation of effective radius the fractional cloud cover and the cloud top temperature all defined at a scale of cloud parameter retrieval the retrieval procedure comprises two separate steps the first one is relative to the angular interpolation and correction of radiance data surface reflection and thermal emission contribution the second step concerns the cloud parameter retrieval as such from interpolated and corrected radiance data the input vector to the retrieval mnns consists of 8 radiometric data in addition to a number of necessary ancillary data such as surface temperature and ground albedo the 8 radiometric data are 5 area averaged radiances over 1 km 1 km pixel and 3 standard deviations of radiance over 1 km 1 km pixel estimated from 0 25 km 0 25 km pixel radiances after evaluating the performance of the neural networks trained for each step we tested the whole retrieval procedure for three types of inhomogeneous and fractional clouds flat top bounded cascade clouds and flat top and non flat top gaussian process clouds all the cloud parameters of these clouds can be retrieved with reasonable accuracy in spite of the fact that the mean and standard deviation of optical thickness of non flat top clouds exhibit some dispersion the inclusion of 0 25 km 0 25 km pixel radiance data as input vector components improved significantly the performance of the cloud parameter retrieval finally we analyzed the consequences of some simplifying assumptions on the retrieved cloud parameters and discussed the perspectives of the cloud parameter retrieval based on the neural networks

organization of tropical convection in a gcm with varying vertical resolution implications for the simulation of the madden julian oscillation experiments using a gcm with two different vertical resolutions show differences in the amount of variability in the tropical upper tropospheric zonal wind component associated with the madden julian oscillation mjo the gcm with lower vertical resolution shows very little variability in this quantity whereas when the vertical resolution is doubled in the free troposphere the gcm produces variability which is of the same strength as observations however the eastward propagation of an enhanced convective region from the indian ocean into the west pacific is not well represented in either simulation of this atmospheric gcm a water covered or aqua planet version of the same gcm is used to investigate the behaviour of tropical convection when the vertical resolution is doubled when the vertical resolution is increased the spectrum of tropical cloud types changes from a bimodal distribution with peaks representing shallow cumulus and deep cumulonimbus clouds to a trimodal distribution with a third peak in mid troposphere near the melting level associated with periods when these mid level congestus clouds are dominant the detrainment from these clouds significantly moistens the mid troposphere the appearance of these congestus clouds is shown to be partly due to improved resolution of the freezing level and the convective processes occurring at this level however due to the way in which convective detrainment is parametrized in this model the vertical profile becomes rather noisy and this too contributes to the change in the nature of the convective clouds the resulting cloud distribution more closely resembles observations particularly during the suppressed phase of the mjo when cumulus congestus is the dominant cloud type

tunneling in squeezing rock the bolu tunnel anatolian motorway turkey abstract the bolu tunnel is subject to considerable deformation due to stress related failure in the rock mass in thrust zones and strike slip faults that transect the tunnel these deformations resulted in some serious geotechnical problems which were overcome either by flexible or extremely heavy support systems the heavy system was used to prevent or bring under control the large deformations that would take place during excavation whereas the flexible method allows the deformations to develop without restraint the heavy support system was used in thrust fault zones and in flysch zones in the bolu tunnel and produced more successful results in comparison to the flexible support system a brief explanation of the tunnel collapse in the duzce earthquake is also provided

analytic representation of the large scale organization of tropical convection the pivotal role of mesoscale organization on the large scale coherence of tropical convection is represented by a nonlinear dynamical model the general model consists of two interlocked systems a mesoscale parameterization of organized convection and a two layer model of large scale equatorial dynamics the lower layer dynamics is rossby gyre like whereas outflow from organized convection maintains the upper layer circulation the transports of zonal momentum in the vertical and meridional directions are key processes an archetype of the general model in spite of being brutally simplified represents the convective organization momentum transport and equatorial superrotation realized by the cloud resolving convection parameterization or superparameterization explicit approach developed by grabowski the mesoscale parameterization is an analytic equivalent of the cloud system resolving models used in this computational approach finally issues in parameterizing convective organization are discussed

abrupt termination of the 1997 98 el nino in response to a madden julian oscillation the role of the madden julian oscillation a global atmospheric wave in the tropics that is associated with convective activity and propagates eastwards with a period of about 30 60 days refs 1 2 in triggering el nino events has been discussed before3 4 5 6 7 8 but its possible connection with a termination of el nino has yet to be investigated despite the difficulty in explaining the timing of el nino terminations by the basic wind induced oceanic wave processes9 10 for the extreme 1997 98 event the mechanism of both onset and termination have been investigated3 but the reason for the abruptness of the termination has yet to be resolved here we present global data of precipitation sea surface temperatures and wind speeds that show a precipitation system associated with an exceptionally strong madden julian oscillation travelling around the equator in may 1998 the propagation of this atmospheric system was associated with an abrupt intensification of the easterly trade winds over the eastern equatorial pacific ocean combined with the already shallow equatorial thermocline in the central and eastern pacific ocean at that time3 these strong winds provided the triggering mechanism for the observed accelerated ending of the 1997 98 el nino event

geodetic evidence and modeling of a slow small scale inflation episode in the thera santorini volcano caldera aegean sea abstract analysis of a radial geodetic monitoring record indicated small scale inflation of the nw part of the thera santorini caldera up to 10 cm baseline length increase between 1994 and 2000 corresponding to up to 2 10 5 strain and subsequent stabilization especially after 2006 as gps data indicate the southern part of the caldera on the contrary remained practically stable this partial caldera inflation was assigned to slow magma intrusion which was not associated with changes in the seismicity using a stochastic approach based on numerical analysis and the theory of graphs and sets the mogi source of this magmatic activity was identified between the nea kammeni and the therasia islets along a major tectonovolcanic lineament at a depth of around 1 km or possibly 5 5 km it remained stable during the whole small scale inflation period and was associated with small scale pressure changes slow deformation events have been observed in other volcanoes as well but they were associated with abrupt seismicity changes

induced deformation during tunnel excavation evidence from geodetic monitoring abstract during tunnel excavation convergence i e a tendency for reduction of the section area of the void formed is observed due to the stress redistribution around the excavation free surface this deformation accumulates with a gradually decreasing rate until an equilibrium level is obtained its amplitude depends on the rock mass conditions the support system and the excavation procedure as well as on the state of stress and is usually recognized as a two dimensional effect i e a deformation confined to a plane normal to the tunnel axis not affecting neighboring sections in the last years electronic theodolites a new generation of geodetic instruments which can describe in detail the 3 d changes in the shape of tunnels during their excavation stage relative to fixed reference frames became available making possible the understanding of the detailed pattern of such changes especially the effect of rejuvenation of deformation in previously stabilized sections while tunnel excavation is progressing analysis of geodetic monitoring records of certain recently constructed tunnels indicates that occasionally large deformation from specific source sections is transferred along the tunnel axis to host neighboring sections causing additional time delayed deformation of previously stabilized sections and necking of the tunnel this induced deformation is not due to effects such as nearby excavations changes in the hydrological conditions etc and to tertiary creep its distribution along the tunnel axis seems to depend on the potential of host sections to accommodate additional stresses from neighboring deformation source sections and it may lead to a progressive domino type failure the overall process is reminiscent of the triggering of new earthquakes by coulomb static stress changes caused by a certain earthquake on the condition that the stress level in the epicentral areas of the new events was close to the rupture limit

multiscale variability of deep convection in relation to large scale circulation in toga coare deep convection over the indo pacific oceanic warm pool in the tropical ocean global atmosphere coupled ocean atmosphere response experiment toga coare occurred in cloud clusters which grouped together in regions favoring their occurrence these large groups of cloud clusters produced large scale regions of satellite observed cold cloud top temperature this paper investigates the manner in which the cloud clusters were organized on time and space scales ranging from the seasonal mean pattern over the whole warm pool region to the scale of individual cloud clusters and their relationship to the large scale circulation and sea surface temperature sst the dominant convective variability was associated with the intraseasonal oscillation iso a large eastward propagating ensemble of cloud clusters marked the iso s progress the meridional structure of the iso was strongly affected by the seasonal cycle with a southward shift from the northern hemisphere in october november to the southern hemisphere in january february the sst had an intraseasonal signal in lagged quadrature with the cold cloudiness and rainfall in coare the sst increased decreased during the convectively suppressed active phases of the iso enhanced low level westerly winds occurred toward the later stages of the enhanced convection periods of the iso though not always centered at the equator the strongest westerlies tended to be located between two synoptic scale cyclonic gyres which were often not symmetric about the equator in the low level wind field this asymmetry in the anomalous equatorial low level westerlies may have different implications for the oceanic response in the coupled atmosphere ocean system than those centered on the equator the cyclonic gyres contained highly concentrated deep convection and in four cases the gyres developed into tropical cyclones within the envelope marking the convectively active phase of the iso cloud clusters were frequently concentrated into westward propagating disturbances with a local periodicity of similar to 2 days these 2 day disturbances have been identified in earlier spectral studies and appear to be related to westward propagating inertio gravity waves in coare they typically contained numerous cloud clusters which underwent a distinct diurnal cycle most of the cloud clusters embedded in the 2 day disturbances moved westward though some were stationary and a few moved eastward a cloud duster tracking program identified groups of clusters lime dusters that exhibited continuity in time and space in the most convectively active period of the iso the tracking program identified almost the entire iso cloud ensemble as a long lasting trackable superconvective system this observation indicates the lack of a distinct scale separation between convection and large scale disturbances during the most intense convective periods in coare

accuracy of the independent pixel approximation for satellite estimates of oceanic boundary layer cloud optical depth a theoretical study has been conducted on the effects of cloud horizontal inhomogeneity on the retrieval of optical depth by remote sensing of visible reflectance forty five landsat scenes of oceanic boundary layer clouds provide a sampling of real cloud fields including trade cumulus open and closed cell broken stratocumulus and solid stratocumulus the spherical harmonic discrete ordinate method shdom radiative transfer model is used to calculate two dimensional reflectances from subsampled cloud strips representing the landsat scenes the independent pixel approximation ipa is used to retrieve optical depth for comparison to the original input results for ipa versus ref are presented on scales from the landsat pixel scale 28 5 m to an imager pixel scale 6 km to near mesoscale 60 km the random error decreases as the averaging scale increases but error due to inhomogeneity remains at the 60 km scale the average error is about 6 for high sun 2 for low sun individual scenes however have retrieved optical depth errors as high as 45 due to horizontal radiative transport the ability to retrieve higher statistical moments of the frequency distribution of optical depth is also assessed sigma the standard deviation of is retrieved quite well up to a point then is underestimated due to the smoothing effect of horizontal radiative transport the gamma function parameter another measure of the width of the frequency distribution is retrieved quite well over a wide range but with a systematic bias which varies with solar zenith angle again due to horizontal radiative transport a method is sought to reduce the optical depth retrieval error using a simple correction based on remotely sensed cloud properties of those considered cloud physical aspect ratio computed here from one possible relation which depends on properties obtainable from remote sensing is found to be the most effective correction parameter the aspect ratio correction reduces the retrieved optical depth bias error by 50 to 100 and the rms error by 20 to 50 correction coefficients are presented at three solar zenith angles this work is limited by its consideration of only single level marine boundary layer clouds assumptions of conservative scattering constant cloud droplet size no gas absorption or surface reflectance and restriction to two dimensional radiative transport future work will attempt to remove some of these limitations the landsat data used are also limited due to radiative smoothing

use of misr measurements to study the radiative transfer of an isolated convective cloud implications for cloud optical thickness retrieval 1 radiative transfer simulations of an isolated deep convective cloud reconstructed with stereo techniques from the multiangle imaging spectroradiometer misr are compared with the reflectances measured at the nine misr viewing angles the simulations were done using a three dimensional monte carlo model in which ocean reflectance aerosol and rayleigh scattering were prescribed to match the surrounding clear sky misr measurements making reasonable assumptions regarding the vertical and horizontal distribution of the volume extinction coefficient we were able to reproduce the misr measurements with the 3d radiative calculations while the uniqueness of the these distributions cannot be proven they all lead to retrievals of much larger cloud optical thickness and cloud water content than for a 1d retrieval averaged over the cloud the difference was a factor of about 3 rising to 9 locally this is a consequence of horizontal photon transport that serves to highlight the inadequacy of 1d retrievals for the case of deep convective cloud concerning the internal cloud properties we noticed the angular distribution of modeled radiances did not match the measured radiances when an ice crystal phase function was applied better estimates of the optical depths and water contents of deep convective clouds appear to be obtainable by integrating an estimate of the extinction coefficient over the vertical cloud extent when this can assessed than by attempting to invert the radiance measured from a single angle view using 1d theory