Search NASA⌕ Search

SEARCH · Search NASA

Results for “exceptions”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Evaluating geothermal and hydrogeologic controls on regional groundwater temperature distribution

Described is a one-dimensional (1-D) analytic solution is developed for heat transport through an aquifer system where the vertical temperature profile in the aquifer is nearly uniform. The general anisotropic form of the viscous heat generation term is developed for use in groundwater flow simulations. The 1-D solution is extended to more complex geometries by solving the equation for piece-wise linear or uniform properties and boundary conditions. A moderately complex example, the Eastern Snake River Plain (ESRP), is analyzed to demonstrate the use of the analytic solution for identifying important physical processes. For example, it is shown that viscous heating is variably important and that heat conduction to the land surface is a primary control on the distribution of aquifer and spring temperatures. Use of published values for all aquifer and thermal properties results in a reasonable match between simulated and measured groundwater temperatures over most of the 300 km length of the ESRP, except for geothermal heat flow into the base of the aquifer within 20 km of the Yellowstone hotspot. Previous basal heat flow measurements (110 mW/m 2 ) made beneath the ESRP aquifer were collected at distances of > 50 km from the Yellowstone Plateau, but a higher basal heat flow of 150 mW/m 2 is required to match groundwater temperatures near the Plateau. As a result, the ESRP example demonstrates how the new tool can be used during preliminary analysis of a groundwater system, allowing efficient identification of the important physical processes that must be represented during more-complex 2-D and 3-D simulations of combined groundwater and heat flow.

58 GEOSCIENCES↗
DOE OSTI2016

Prolonged El Niño conditions in 2014-2015 and the rapid intensification of Hurricane Patricia in the eastern Pacific: EL NIÑO AND HURRICANE PATRICIA

Hurricane Patricia was the most intense tropical cyclone on record in the eastern North Pacific or Atlantic, reaching a peak intensity of 95 m s -1 only 30 hours after attaining hurricane status (33 m s -1 ). Here it is shown that exceptionally warm sea surface temperatures (SSTs), a deeper than normal thermocline, and strong near-surface salinity stratification all aided Patricia’s rapid intensifciation, combining to increase its Dynamic Potential Intensity by 10–21 m s -1 . Anomalous surface warming and thermocline deepening along Patricia’s track were driven by prolonged El Niño during 2014–15 and punctuated by the buildup to the extreme El Niño of 2015–16. In the region where Patricia intensified, SST was 1.5°C higher and sea surface height was 10 cm higher compared to conditions during the last extreme El Niño in 1997, emphasizing the extraordinary nature of the 2015 anomalies.

58 GEOSCIENCES↗
DOE OSTI2017

Anthropogenic warming impacts on California snowpack during drought

Sierra Nevada climate and snowpack is simulated during the period of extreme drought from 2011 to 2015 and compared to an identical simulation except for the removal of the twentieth century anthropogenic warming. Anthropogenic warming reduced average snowpack levels by 25%, with middle-to-low elevations experiencing reductions between 26 and 43%. In terms of event frequency, return periods associated with anomalies in 4 year 1 April snow water equivalent are estimated to have doubled, and possibly quadrupled, due to past warming. Here, we also estimate effects of future anthropogenic warmth on snowpack during a drought similar to that of 2011–2015. Further snowpack declines of 60–85% are expected, depending on emissions scenario. The return periods associated with future snowpack levels are estimated to range from millennia to much longer. Therefore, past human emissions of greenhouse gases are already negatively impacting statewide water resources during drought, and much more severe impacts are likely to be inevitable.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Foreshock wave interaction with the magnetopause: Signatures of mode conversion

Our previous hybrid simulation under a radial interplanetary magnetic field (IMF) and a supercritical solar wind Mach number has shown that foreshock compressional waves originated from the quasi–parallel (Q–∥) shock are mode converted to kinetic Alfvén waves (KAWs) at the Alfvén resonance surface of the subsolar magnetopause. In this paper, three–dimensional global dayside mode conversion is investigated for cases under various solar wind conditions using the global hybrid model. The global patterns and propagations of KAWs are distinguished and presented. Under a near–critical Mach number ( M A =3), KAW structures due to mode conversion exhibit a feature of broader excitation regions in the magnetopause boundary layer (MPBL) compared to supercritical Mach number ( M A =5) shocks. For cases with an oblique IMF with supercritical Mach numbers ( M A =5), the amplitude of magnetosheath compressional waves is larger at the quasi–parallel shock (Q–∥) than at the quasi–perpendicular (Q–⊥) shock. Downstream of the Q–∥ shock, there is a general trend that the perturbations of density ( N ) and magnetic field ( B ) change from predominantly in–phase in the magnetosheath to antiphase near the MPBL. While downstream of the Q–⊥ shock, an antiphase relation between N and B is dominant throughout the magnetosheath and magnetopause except near the shock transition. The compressional drivers are found to reach an extended region of the magnetopause due to the combined effects of wave propagation in the plasma frame and flow convection, leading to a broad region of mode conversion at the magnetopause. Subsequently, the resulting KAWs can be carried to the regions downstream of the Q–⊥ shock owing to the flow convection at the magnetopause. Furthermore the KAWs propagate poleward along the geomagnetic field lines and meanwhile are carried tailward by the ambient flows, and they are more intense in the downstream of Q–∥ shocks than downstream of Q–⊥ shocks.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

An ensemble of ocean reanalyses for 1815-2013 with sparse observational input

This paper describes a new eight-member ensemble of ocean reanalyses spanning nearly 200 years from 1815 to 2013 generated using the Simple Ocean Data Assimilation system with sparse observational input (SODAsi) to explore long-term changes in the oceans. The eight ensemble members assimilate surface temperature observations and use surface boundary conditions from an atmospheric reanalysis that is loosely coupled to the ocean reanalysis. In this work, both surface and subsurface quantities, such as dynamic height and heat content, show a broad spectrum of variability. Surface temperature trends from 1815 to 2013 are positive in most regions, with some important exceptions; the central Tropical Pacific, around Antarctica, and in the Gulf Stream and Kuroshio extension regions all show cooling trends. A near-global average shows warming of about 0.8°C over the full period, with most of the warming occurring after 1920. There is pronounced multidecadal variability in both the midlatitude and tropical oceans. In the North Atlantic Ocean, temperature variability is highly correlated with the meridional overturning stream function, with the largest correlation occurring when the stream function is advanced by 9 years. Trends of upper ocean heat content and dynamic height from the 1950s onward compare well with previously published values. Globally averaged heat content of the upper 700 m shows a nearly linear rise after the 1920s, requiring a net downward surface heat flux increase of 0.47 W m -2 into the ocean. This is close to published estimates of the increased flux required to explain the heat content increase from 1971 to 2010.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Turbulent mixing and removal of ozone within an Amazon rainforest canopy

Simultaneous profiles of turbulence statistics and mean ozone mixing ratio are used to establish a relation between eddy diffusivity and ozone mixing within the Amazon forest. A one–dimensional diffusion model is proposed and used to infer mixing time scales from the eddy diffusivity profiles. Data and model results indicate that during daytime conditions, the upper (lower) half of the canopy is well (partially) mixed most of the time and that most of the vertical extent of the forest can be mixed in less than an hour. During nighttime, most of the canopy is predominantly poorly mixed, except for periods with bursts of intermittent turbulence. Even though turbulence is faster than chemistry during daytime, both processes have comparable time scales in the lower canopy layers during nighttime conditions. Nonchemical loss time scales (associated with stomatal uptake and dry deposition) for the entire forest are comparable to turbulent mixing time scale in the lower canopy during the day and in the entire canopy during the night, indicating a tight coupling between turbulent transport and dry deposition and stomatal uptake processes. Because of the significant time of day and height variability of the turbulent mixing time scale inside the canopy, it is important to take it into account when studying chemical and biophysical processes happening in the forest environment. In conclusion, the method proposed here to estimate turbulent mixing time scales is a reliable alternative to currently used models, especially for situations in which the vertical distribution of the time scale is relevant.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Cloud and circulation feedbacks in a near‐global aquaplanet cloud‐resolving model

Abstract A near‐global aquaplanet cloud‐resolving model (NGAqua) with fixed meridionally varying sea‐surface temperature (SST) is used to investigate cloud feedbacks due to three climate perturbations: a uniform 4 K SST increase, a quadrupled‐CO 2 concentration, and both combined. NGAqua has a horizontal resolution of 4 km with no cumulus parameterization. Its domain is a zonally periodic 20,480 km‐long tropical channel, spanning 46°S–N. It produces plausible mean distributions of clouds, rainfall, and winds. After spin‐up, 80 days are analyzed for the control and increased‐SST simulations, and 40 days for those with quadrupled CO 2 . The Intertropical Convergence Zone width and tropical cloud cover are not strongly affected by SST warming or CO 2 increase, except for the expected upward shift in high clouds with warming, but both perturbations weaken the Hadley circulation. Increased SST induces a statistically significant increase in subtropical low cloud fraction and in‐cloud liquid water content but decreases midlatitude cloud, yielding slightly positive domain‐mean shortwave cloud feedbacks. CO 2 quadrupling causes a slight shallowing and a statistically insignificant reduction of subtropical low cloud fraction. Warming‐induced low cloud changes are strongly correlated with changes in estimated inversion strength, which increases modestly in the subtropics but decreases in the midlatitudes. Enhanced clear‐sky boundary layer radiative cooling in the warmer climate accompanies the robust subtropical low cloud increase. The probability distribution of column relative humidity across the tropics and subtropics is compared between the control and increased‐SST simulations. It shows no evidence of bimodality or increased convective aggregation in a warmer climate.

58 GEOSCIENCES↗
DOE OSTI2018

Projected Changes in the Asian‐Australian Monsoon Region in 1.5°C and 2.0°C Global‐Warming Scenarios

Abstract In light of the Paris Agreement, it is essential to identify regional impacts of half a degree additional global warming to inform climate adaptation and mitigation strategies. We investigate the effects of 1.5°C and 2.0°C global warming above preindustrial conditions, relative to present day (2006–2015), over the Asian‐Australian monsoon region (AAMR) using five models from the Half a degree Additional warming, Prognosis and Projected Impacts (HAPPI) project. There is considerable intermodel variability in projected changes to mean climate and extreme events in 2.0°C and 1.5°C scenarios. There is high confidence in projected increases to mean and extreme surface temperatures over AAMR, as well as more‐frequent persistent daily temperature extremes over East Asia, Australia, and northern India with an additional 0.5°C warming, which are likely to occur. Mean and extreme monsoon precipitation amplify over AAMR, except over Australia at 1.5°C where there is uncertainty in the sign of the change. Persistent daily extreme precipitation events are likely to become more frequent over parts of East Asia and India with an additional 0.5°C warming. There is lower confidence in projections of precipitation change than in projections of surface temperature change. These results highlight the benefits of limiting the global‐mean temperature change to 1.5°C above preindustrial, as the severity of the above effects increases with an extra 0.5°C warming.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Quantifying black carbon deposition over the Greenland ice sheet from forest fires in Canada

We identify an important Black Carbon (BC) aerosol deposition event that was observed in snow stratigraphy and dated to between 27 July 2013 – 2 August 2013. This event comprises a significant portion (~60%) of total deposition over a 10 month period (July 2013 – April 2014). Here we link this event to forest fires burning in Canada during summer 2013 using modeling and remote sensing tools. Aerosols were detected by both the CALIOP and MODIS instruments during transport between Canada and Greenland, confirming that this event involved emissions from forest fires in Canada. We use high-resolution regional chemical transport mod-eling (WRF-Chem) combined with high-resolution fire emissions (FINNv1.5) to study aerosol emissions, transport, and deposition during this event. The model accurately captures the timing of the BC deposition event and shows that the major contribution to deposition during this event is emissions originating from fires in Canada. However, the model under-predicts aerosol deposition compared to measurements at all sites by a factor of 2–100. Under-prediction of modeled BC deposition originates from uncertainties in fire emissions combined with uncertainties in aerosol scavenging by clouds. This study suggests that it is possible to describe the transport of an exceptional smoke event on regional and continental scales. Improvements in model descriptions of precipitation scavenging and emissions from wildfires are needed to correctly predict deposition, which is critical for determining the climate impacts of aerosols that originate from fires.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

A Low Viscosity Lunar Magma Ocean Forms a Stratified Anorthitic Flotation Crust With Mafic Poor and Rich Units

Much of the lunar crust is monomineralic, comprising >98% plagioclase. The prevailing model argues the crust accumulated as plagioclase floated to the surface of a solidifying lunar magma ocean (LMO). Whether >98% pure anorthosites can form in a flotation scenario is debated. An important determinant of the efficiency of plagioclase fractionation is the viscosity of the LMO liquid, which was unconstrained. Here we present results from new experiments conducted on a late LMO-relevant ferrobasaltic melt. The liquid has an exceptionally low viscosity of 0.22 $+0.11\atop{-0.19}$to 1.45 $+0.46\atop{-0.82}$ Pa s at experimental conditions (1,300–1,600°C; 0.1–4.4 GPa) and can be modeled by an Arrhenius relation. Extrapolating to LMO-relevant temperatures, our analysis suggests a low viscosity LMO would form a stratified flotation crust, with the oldest units containing a mafic component and with very pure younger units. Old, impure crust may have been buried by lower crustal diapirs of pure anorthosite in a serial magmatism scenario.

58 GEOSCIENCES↗
DOE OSTI2018

Spatiotemporal Patterns of Precipitation-Modulated Landslide Deformation From Independent Component Analysis of InSAR Time Series

We present that long-term landslide deformation is disruptive and costly in urbanized environments. We rely on TerraSAR-X satellite images (2009–2014) and an improved data processing algorithm (SqueeSAR™) to produce an exceptionally dense Interferometric Synthetic Aperture Radar ground deformation time series for the San Francisco East Bay Hills. Independent and principal component analyses of the time series reveal four distinct spatial and temporal surface deformation patterns in the area around Blakemont landslide, which we relate to different geomechanical processes. Two components of time-dependent landslide deformation isolate continuous motion and motion driven by precipitation-modulated pore pressure changes controlled by annual seasonal cycles and multiyear drought conditions. Two components capturing more widespread seasonal deformation separate precipitation-modulated soil swelling from annual cycles that may be related to groundwater level changes and thermal expansion of buildings. Lastly, high-resolution characterization of landslide response to precipitation is a first step toward improved hazard forecasting.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

The Characteristic Pitch Angle Distributions of 1 eV to 600 keV Protons Near the Equator Based On Van Allen Probes Observations

Understanding the source and loss processes of various plasma populations is greatly aided by having accurate knowledge of their pitch angle distributions (PADs). Here we statistically analyze ~1 eV to 600 keV hydrogen (H+) PADs near the geomagnetic equator in the inner magnetosphere based on Van Allen Probes measurements, to comprehensively investigate how the H+ PADs vary with different energies, magnetic local times (MLTs), L shells, and geomagnetic conditions. Our survey clearly indicates four distinct populations with different PADs: a pancake distribution of the plasmaspheric H+ at low L shells except for dawn sector; a bidirectional field-aligned distribution of the warm plasma cloak; pancake or isotropic distributions of ring current H+; radiation belt particles show pancake, butterfly, and isotropic distributions depending on their energy, MLT, and L shell. Meanwhile, the pancake distribution of ring current H+ moves to lower energies as shell increases, which is primarily caused by adiabatic transport. Furthermore, energetic H+ (>10 keV) PADs become more isotropic following the substorm injections, indicating wave-particle interactions. The radiation belt H+ butterfly distributions are identified in a narrow energy range of 100 < E < 400 keV at large L ( L > 5), which are less significant during quiet times and extend from dusk to dawn sector through midnight during substorms. In conclusion, the different PADs near the equator provide clues of the underlying physical processes that produce the dynamics of these different populations.

58 GEOSCIENCES↗
DOE OSTI2017

The Evolution of the Plasma Sheet Ion Composition: Storms and Recoveries: Plasma Sheet Ion Composition

The ion plasma sheet (~few hundred eV to ~few 10s keV) is usually dominated by H + ions. Here, changes in ion composition within the plasma sheet are explored both during individual events, and statistically during 54 calm-to-storm events and during 21 active-to-calm events. Ion composition data from the HOPE (Helium, Oxygen, Proton, Electron) instruments onboard Van Allen Probes satellites provide exceptional spatial and temporal resolution of the H + , O + , and He + ion fluxes in the plasma sheet. H+ shown to be the dominant ion in the plasma sheet in the calm-to-storm transition. However, the energy-flux of each ion changes in a quasi-linear manner during extended calm intervals. Heavy ions (O + and He + ) become increasingly important during such periods as charge-exchange reactions result in faster loss for H + than for O + or He + . Results confirm previous investigations showing that the ion composition of the plasma sheet can be largely understood (and predicted) during calm intervals from knowledge of: (a) the composition of previously injected plasma at the onset of calm conditions, and (b) use of simple drift-physics models combined with calculations of charge-exchange losses.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2017

Diffusion Creep of Enstatite at High Pressures Under Hydrous Conditions: Diffusion Creep of Hydrous Enstatite

Mantle convection and large-scale plate motion depend critically on the nature of the lithosphere-asthenosphere boundary and thus on the viscosity structure of Earth's upper mantle, which is determined by the rheological properties of its constituent minerals. To constrain the flow behavior of orthopyroxene, the second most abundant constituent of the upper mantle, deformation experiments were carried out in triaxial compressive creep on fine-grained (~6 μm) samples of enstatite at high pressures (3.8–6.3 GPa) and high temperatures (1323–1573 K) using a deformation-DIA apparatus. Based on results from this study, the deformation behavior of enstatite is quantitatively presented in the form of a flow law that describes the dependence of deformation rate on differential stress, water fugacity, temperature, and pressure. Specifically, the creep rate depends approximately linearly on stress, indicating deformation in the diffusion creep regime. A least squares regression fit to our data yielded a flow law for diffusion creep with an activation energy of ~200 kJ/mol and an activation volume of ~14 × 10 -6 m 3 /mol. The magnitude of the water-weakening effect is similar to that for olivine with a water fugacity exponent of r ≈ 0.7. This strong dependence of viscosity on water fugacity (concentration) indicates that the viscosity of an orthopyroxene-bearing mantle varies from one geological setting to another, depending on the large-scale water distribution. Based on the rheology contrast between olivine and enstatite, we conclude that olivine is weaker than enstatite throughout most of the upper mantle except in some shallow regions in the diffusion creep regime.

36 MATERIALS SCIENCE↗
DOE OSTI2017

The Turbulent Structure of the Arctic Summer Boundary Layer During The Arctic Summer Cloud‐Ocean Study

Abstract The mostly ice covered Arctic Ocean is dominated by low‐level liquid‐ or mixed‐phase clouds. Turbulence within stratocumulus is primarily driven by cloud top cooling that induces convective instability. Using a suite of in situ and remote sensing instruments we characterize turbulent mixing in Arctic stratocumulus, and for the first time we estimate profiles of the gradient Richardson number at relatively high resolution in both time (10 min) and altitude (10 m). It is found that the mixing occurs both within the cloud, as expected, and by wind shear instability near the surface. About 75% of the time these two layers are separated by a stably stratified inversion at 100–200 m altitude. Exceptions are associated with low cloud bases that allow the cloud‐driven turbulence to reach the surface. The results imply that turbulent coupling between the surface and the cloud is sporadic or intermittent.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

A Case Study in Low Aerosol Number Concentrations Over the Eastern North Atlantic: Implications for Pristine Conditions in the Remote Marine Boundary Layer

We present a case study (20 September to 13 October 2015) of synergistic, multi-instrument observations of aerosols, clouds, and the marine boundary layer (MBL) at the Eastern North Atlantic (ENA) Atmospheric Radiation Measurement site centered on a period of exceptionally low (20–50 cm -3 ) surface accumulation mode (0.1–1 μm) aerosol particle number concentrations. We divide the case study into three regimes (high, clean, and ultraclean) based on daily median number concentrations and compare finer resolution (hourly or less) observations between these regimes. The analysis focuses on the possibility of using these ultraclean events to study pristine conditions in the remote MBL, as well as examining evidence for a recently proposed conceptual model for the large-scale depletion of cloud condensation nuclei-sized particles in postfrontal air masses. Relative to the high and clean regimes, the ultraclean regime tends to exhibit significantly fewer particles between 0.1 and 0.4 μm in diameter and a relatively increased prevalence of larger accumulation mode particles. In addition, supermicron particles tend to dominate total scattering in the ultraclean regime, and there is little evidence for absorbing aerosol. These observations are more in-line with a heavily scavenged but natural marine aerosol population and minimal contribution from continental sources such as anthropogenic pollution, biomass burning, or dust. The air masses with the consistently lowest accumulation mode aerosol number concentrations are largely dominated by heavily drizzling clouds with high liquid water path cores, deep decoupled boundary layers, open cellular organization, and notable surface forcing of subcloud turbulence, even at night.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Improving Empirical Magnetic Field Models by Fitting to In Situ Data Using an Optimized Parameter Approach

A method for comparing and optimizing the accuracy of empirical magnetic field models using in situ magnetic field measurements is presented in this paper. The optimization method minimizes a cost function—τ—that explicitly includes both a magnitude and an angular term. A time span of 21 days, including periods of mild and intense geomagnetic activity, was used for this analysis. A comparison between five magnetic field models (T96, T01S, T02, TS04, and TS07) widely used by the community demonstrated that the T02 model was, on average, the most accurate when driven by the standard model input parameters. The optimization procedure, performed in all models except TS07, generally improved the results when compared to unoptimized versions of the models. Additionally, using more satellites in the optimization procedure produces more accurate results. This procedure reduces the number of large errors in the model, that is, it reduces the number of outliers in the error distribution. The TS04 model shows the most accurate results after the optimization in terms of both the magnitude and direction, when using at least six satellites in the fitting. It gave a smaller error than its unoptimized counterpart 57.3% of the time and outperformed the best unoptimized model (T02) 56.2% of the time. Its median percentage error in |B| was reduced from 4.54% to 3.84%. Finally, the difference among the models analyzed, when compared in terms of the median of the error distributions, is not very large. However, the unoptimized models can have very large errors, which are much reduced after the optimization.

58 GEOSCIENCES↗
DOE OSTI2018

Monitoring and Modeling Caprock Integrity at the In Salah Carbon Dioxide Storage Site, Algeria

The In Salah gas development project, initiated in 2004, involves the long-term storage of waste carbon dioxide associated with natural gas production at several central Algerian fields. Rather then vent the extracted CO 2 into the atmosphere the operators, BP, Sonatrach, and Statoil chose to have the gas compressed, dehydrated, transported, and injected into a deep saline aquifer leg of the Krechba gas reservoir (Matheison et al. 2011). For this effort three horizontal state-of-the-art injection wells were drilled to a depth of 1500-1800m, using geo-steering technology to follow the roughly 20m thick reservoir. To maximize the injectivity, the wells were oriented perpendicular to the direction of maximum stress, the dominant fracture direction. Long-term plans were to store up to 17 million tonnes of carbon dioxide during the life of the program (Matheison et al. 2010). The project at In Salah was a pioneering effort in several respects and involved the investment of over 100 million dollars by the member companies. One feature that distinguishes In Salah from several other industrialscale CO 2 sequestration projects, such as Sleipner (Chadwick et al. 2012), Weyburn (White et al. 2011), Decatur (Kaven et al. 2014), and Aquastore (Worth et al. 2014) is the generally smaller storage volume in terms of overall reservoir thickness and lower average porosities of around 15%. With the exception of Weyburn, these other sites are characterized by generally thick sequences of high porosity sandstones. Therefore, one might expect that the pressure buildup near the wells could be larger at In Salah, with consequences for reservoir deformation and caprock strain. The role of fractures in providing storage and increasing reservoir permeability is one factor that would likely impact the pressure distribution around the well. However, the detailed effect of existing fractures on flow was not established prior to the injection at In Salah. The unique features of the In Salah storage site point to the importance of wellbore, geophysical, and geochemical monitoring to ensure that the integrity of the storage complex is maintained both during and after injection. In 2005 a Joint Industry Project (JIP) was set up, in an effort to use various geophysical, geochemical, and production techniques to monitor the fate of the injected carbon dioxide (Matheison et al. 2011). Here in this paper we describe the efforts made to monitoring the fate of the injected carbon dioxide, the state of the caprock, the estimated outcome of the storage effort, and some of the uncertainties that remain.

58 GEOSCIENCES↗