Unlike the United States, Nigeria's installed overall electricity capacity is 12.8 GW, while the operational capacity is estimated to be 3.9 GW which is well below the current demand of 98 GW. This results in a consumer power demand shortfall of 94.1 GW across the country. As a result of this wide gap between demand and generation, only about 45% of Nigeria's citizens have access to electricity. In this paper, a comparative feasibility analysis of the utilization of a photovoltaic system with energy storage for residential application is presented. The comparative analysis is conducted to compare the feasibility of using a solar Farm with an energy storage system between the US and Nigeria. This analysis is carried out using a model developed by IREQ Hydro-Quebec Research Institute. The results are shown in phasor form to analyze the energy stored, solar intensity, and also enable the community in making informed decisions regarding reducing grid dependency.
Growing evidence indicates that a selected group of global-scale waves from the lower 3 atmosphere constitute a significant source of ionosphere-thermosphere (IT, 100-600 km) 4 variability. Due to the geometry of the magnetic field lines, this IT coupling occurs mainly at low 5 latitudes (< 30 •) and is driven by waves originating in the tropical troposphere such as the diurnal 6 eastward propagating tide with zonal wave number s =-3 (DE3) and the quasi-3-day ultra-fast 7 Kelvin wave with s =-1 (UFKW1). In this work, over 2 years of simultaneous in situ ion densities 8 from Ion Velocity Meters (IVMs) onboard the Ionospheric Connection Explorer (ICON) near 9 590 km and the Scintillation Observations and Response of the Ionosphere to Electrodynamics 10 (SORTIE) CubeSat near 420 km, along with remotely-sensed lower (ca. 105 km) and middle 11 (ca. 220 km) thermospheric horizontal winds from ICON's Michelson Interferometer for Global 12 High-resolution Thermospheric Imaging (MIGHTI) are employed to demonstrate a rich spectrum 13 of waves coupling these IT regions. Strong DE3 and UFKW1 topside ionospheric variations are 14 traced to lower thermospheric zonal winds, while large diurnal s = 2 (DW2) and zonally symmetric 15 (D0) variations are traced to middle thermospheric winds generated in situ. Analyses of diurnal 16 tides from the Climatological Tidal Model of the Thermosphere (CTMT) reveal general agreement 17 near 105 km, with larger discrepancies near 220 km due to in situ tidal generation not captured 18 by CTMT. This study highlights the utility of simultaneous satellite measurements for studies of IT 19 coupling via global-scale waves. 20
Changes in the Atlantic Meridional Overturning Circulation (AMOC) and associated Meridional Heat Transport (MHT) can affect climate and weather patterns, regional sea levels, and ecosystems. However, despite its importance, direct observations of the AMOC are still limited spatially and temporally, particularly in the South Atlantic. The main goal of this study is to implement a cost-effective trans-basin section to estimate for the first time the AMOC at 22.5°S, using only sustained ocean observations. For this, an optimal mapping method that minimizes the difference between surface in-situ dynamic height and satellite altimetry was developed to retrieve monthly temperature and salinity profiles from Argo and XBT data along the 22.5°S section. The mean AMOC and MHT for 22.5°S were estimated as 15.55±2.81 Sv and 0.68±0.18 PW, respectively, and are stronger during austral fall/winter and weaker in spring. The high-resolution XBT data available at the western boundary are vital for capturing the highly variable Brazil Current, and our section shows a significant improvement when compared to Argo database. The mean values, interannual and seasonal time series of AMOC and MHT were compared with other products. At 22.5S the North Atlantic Deep Water is divided into two cores that flow along both western and eastern boundaries near 2500 m depth. Our results suggest a greater influence of western boundary system on the AMOC variability at 22.5°S; highlight the importance of high resolution in situ data for AMOC estimations; and contribute for a better understanding of AMOC and MHT variability in the South Atlantic.
In polar regions, sea ice is a crucial mediator of the interaction between earth’s atmosphere and oceans. Its formation and breakup is intimately connected with local weather patterns and larger-scale climatic processes. During the spring melt and breakup period, snow-covered ice transitions to open water in a matter of weeks. This has a profound impact on the use of sea ice in coastal Arctic regions by Indigenous People, where activities such as hunting and fishing are central to community livelihood. In order to investigate the physical phenomena at the heart of this process, a set of targeted, intensive observations were made over Spring sea ice melt and breakup in Kotzebue Sound, Alaska. This program is part of the Ikaaġvik Sikukun project, a collaborative effort in which an Indigenous Elder advisory council from Kotzebue and scientists participated in co-production of hypotheses and observational research, including a stronger understanding of the physical properties of sea ice during spring melt. Data were collected using high-endurance, fixed-wing uncrewed aerial vehicles (UAVs) containing custom-built scientific payloads. Here we present the results of these measurements. Repeated flights over the measurement period captured the early stages of the transition from a white, snow-covered state to a broken up, bare/blue-green state. We found that the reflectivity of a surface type depends on the size and shape of the features which constitute it. Specifically, large bare blue-green ice features were found to be least reflective, while large snowy/white ice features were found to be most reflective.
SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) is a 10-channel infrared radiometer that is one of four instruments on the NASA TIMED (Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics) satellite mission to study the structure, energetics, chemistry, and dynamics of the Earth’s mesosphere and lower thermosphere. The TIMED spacecraft was launched into a 625 km circular polar orbit (74.1º inclination) via a Boeing Delta II rocket from Vandenberg Air Force Base on 7 December 2001. SABER continues to operate nominally and collect data routinely as it has for over 21 years. Over 2,200 peer-reviewed journal articles have been published worldwide using SABER data. A list of these articles is included in the Supporting Information accompanying this paper. This paper presents a detailed technical description of the SABER instrument including major subsystems of the instrument and technical performance parameters. This paper comprehensively describes the instrument and its components and provides final instrument design and performance parameters. The motivation for this paper is to document this information permanently for future reference. The Space Dynamics Laboratory (SDL) of Utah State University designed, fabricated, and calibrated the SABER instrument in close collaboration with NASA Langley Research Center, Hampton University, and Global Atmospheric Technologies and Science (GATS).
The use of machine learning (ML) for the online correction of coarse-resolution atmospheric models has proven effective in reducing biases in near-surface temperature and precipitation rate. However, this often introduces biases in the upper atmosphere and improvements are not always reliable across ML-corrective models trained with different random seeds. Furthermore, ML corrections can feed back on the baseline physics of the atmospheric model and produce profiles that are outside the distribution of samples used in training, leading to low confidence in the predicted corrections. This study introduces the use of a novelty detector to mask the predicted corrections when the atmospheric state is deemed out-of-sample. The novelty detector is trained on profiles of temperature and specific humidity in a semi-supervised fashion using samples from the coarsened reference fine-resolution simulation. Offline, the novelty detector determines more columns to be out-of-sample in simulations which are known, using simple metrics like mean bias, to drift further from the reference simulation. Without novelty detection, corrective ML leads to the development of undesirably large climate biases for some ML random seeds but not others. Novelty detection deems about 21% of columns to be novelties in year-long simulations. The spread in the root mean square error (RMSE) of time-mean spatial patterns of surface temperature and precipitation rate across a random seed ensemble is sharply reduced when using novelty detection. In particular, the random seed with the worst RMSE is improved by up to 60% (depending on the variable) while the best seed maintains its low RMSE.
We present a robust approach for quantitative precipitation estimation (QPE) for water resources management in mountainous catchments, where rainfall sums and variability are correlated with orographic elevation, but density of rain gauges does not allow for advanced geostatistical interpolation of rainfall fields. Key of the method is modelling rainfall at unobserved locations by their elevation-dependent expected daily mean, and a daily fluctuation which is determined by spatial interpolation of the residuals of neighbouring rain gauges, scaled according to the elevation difference. The scaling factor is defined as the ratio of covariance and variance, in analogy to the “beta” used in economics. The approach is parameterized and illustrated for the Chirilu catchments (Chillón, Rímac, Lurín) in the Andes near Lima, Peru. The results are compared to conventional IDW (inverse-distance weighting) interpolation and a merged national rainfall product. The method results in QPE that are better matching with observed discharges. The combination of inverse-distance weighting with β-scaling thus provides a robust and flexible means to estimate rainfall input to mesoscale mountainous catchments.
Universal Time UT variations in many magnetospheric state indicators and indices have recently been reviewed by (Lockwood and Milan, 2023). Key effects are introduced into magnetospheric dynamics by the eccentric nature of Earth’s magnetic field, features that cannot be reproduced by a geocentric field model. This paper studies the UT variation in the occurrence of substorm onsets and uses a simple Monte-Carlo model to show how it can arise for an eccentric field model from the effect of the diurnal motions of Earth’s poles on the part of the geomagnetic tail where substorms are initiated. These motions are in any reference frame that has an X axis that points from the center of the Earth to the center of the Sun and are caused by Earth’s rotation. The premise behind the model is shown to be valid using a super-posed epoch study of the conditions leading up to onset. These studies also show the surprising degree of preconditioning required, ahead of the growth phase, for onset to occur. A key factor is the extent to which pole motions caused by Earth’s rotation influence the near-Earth tail at the relevant X coordinate. Numerical simulations by a global MHD model of the magnetosphere reveal the required effect to generate the observed UT variations and with right order of amplitude, albeit too small by a factor of about one third. Reasons why this discrepancy may have arisen for the simulations used are discussed.
Magnetic reconnection occurs in turbulent plasmas like shock transition regions, while its exact role in energy dissipation therein is not yet clear. We perform a 2D particle-in-cell simulation for foreshock waves and study electron heating associated with reconnection. The probability distribution of Te exhibits a shift to higher values near reconnection X-lines compared to elsewhere. By examining the Te evolution using the superposed epoch analysis, we find that Te is higher in reconnection than in non-reconnecting current sheets, and Te increases over the ion cyclotron time scale. The heating rate of Te is 10%-40% miVA2, where VA is the average ion Alfvén speed in reconnection regions, which demonstrates the importance of reconnection in heating electrons. We further investigate the bulk electron energization mechanisms by decomposing under guiding center approximations. Around the reconnection onset, E|| dominates the total energization partly contributed by electron holes, and the perpendicular energization is dominant by the magnetization term associated with the gyro-motion in the inhomogeneous fields. The Fermi mechanism contributes negative energization at early time mainly due to the Hall effect, and later the outflow in the reconnection plane contributes more dominant positive values. After a couple of ion cyclotron periods from reconnection onset, the Fermi mechanism dominates the energization. A critical factor for initiating reconnection is to drive current sheets to the de-scale thickness. The reconnection structures can be complicated due to flows originated from the ion-scale waves, and interactions between multiple reconnection sites. These features may assist future analysis of observation data.
The weak-temperature gradient (WTG) approximation has been a popular method used to couple convection in limited-area domain simulations to the large-scale dynamics. Two major implementations that use the WTG approximation have gained popular use over the past two decades - the Temperature Gradient Relaxation implementation and the Damped Gravity Wave implementation. Our comparison of these different WTG implementations in an idealised framework result in different model behaviour, with implications on the nature of convective self-aggregation in similarly idealised setups. A further investigation shows that the different model behaviour is caused by the treatment of the different baroclinic modes by the different WTG implementations. More specifically, we hypothesise that the ratio of the strengths of the baroclinic modes is important in determining if multiple-equilibria states are obtained under different WTG implementations. By varying the strengths of these two baroclinic modes, we are thus able to understand the differences between the WTG schemes.
Atmospheric mercury (Hg) is deposited to land surfaces mainly through vegetation uptake. Foliage stomatal gas exchange plays an important role for net vegetation Hg uptake, because foliage assimilates Hg via the stomata. Here, we use empirical relationships of foliar Hg uptake by forest tree species to produce a spatially highly resolved (1 km2) map of foliar Hg fluxes to European forests over one growing season. The modelled forest foliar Hg uptake flux is 23 ± 12 Mg Hg season−1, which agrees with previous estimates from literature. We spatially compare forest Hg fluxes with modelled fluxes of the chemistry-transport model GEOS-Chem and find a good overall agreement. For European pine forests, stomatal Hg uptake was shown to be sensitive to prevailing conditions of relatively high ambient water vapor pressure deficit (VPD). We tested a stomatal uptake model for the total pine needle Hg uptake flux during four previous growing seasons (1994, 2003, 2015/2017, 2018) and two climate change scenarios (RCP 4.5 and RCP 8.5). The resulting modelled total European pine needle Hg uptake fluxes are in a range of 8.0 - 9.3 Mg Hg season−1 (min - max). The lowest pine forest needle Hg uptake flux to Europe (8 Mg Hg season−1) among all investigated growing seasons is associated with unusually hot and dry ambient conditions in the European summer 2018, highlighting the sensitivity of the investigated flux to prolonged high VPD. We conclude, that stomatal modelling is particularly useful to investigate changes in Hg deposition in the context of extreme climate events.
The instabilities produced by a linear model of the tropical atmosphere coupled to a prognostic equation for water vapour are investigated. For parameter regimes relevant to the Indo-Pacific warm pool, the long-time asymptotic behaviour of the unstable waves is found to be absolutely unstable, so that the amplitude of disturbances will grow in time at every point in the domain. Other limits of the system do not produce this same behaviour at these length and time scales. It is shown that the resultant long-time behaviour of the instability is characterized by roughly equal roles for temperature and moisture fluctuations in setting the thermodynamic tendency of the waves. Under the assumption of a zonally varying flow, it is shown analytically that localized regions of instability may be formed, again using parameter choices relevant to the warm pool. The dynamics and thermodynamics of these local instabilities show some correspondence with the observed development of the Madden-Julian Oscillation as it propagates through the warm pool.
Correspondence to: Dimitre Karamanev (firstname.lastname@example.org) Recently, an Editorial titled Global warming is due to an enhanced greenhouse effect, and anthropogenic heat emissions currently play a negligible role at the global scale (Kleidon et al., 2023) was published in the journal Earth System Dynamics. In it the Chief Editors state: "From time to time, we receive submissions at Earth System Dynamics claiming that global warming, or at least a significant part of it, is caused by factors other than the direct and indirect effect of anthropogenic greenhouse gas emissions. A number of these submissions claim that the increase in observed temperatures is due to the emission of heat from human activities… Such submissions would not have passed peer review in Earth System Dynamics as they ignore basic textbook knowledge and would indeed typically be rejected prior to entering the open-discussion peer review phase." It should be emphasized that discoveries "ignoring basic textbook knowledge" are among the strongest drivers of science (Newton, 1687; Einstein, 1905; Galilei, 1590) and should not be ignored unless they are deemed incorrect. And the determination of their correctness is performed in a peer-review process. On a smaller scale, it was recently found that the assumption that the motion of free rising and free falling rigid bodies are governed by the same physical principles (Newton, 1687; Galilei, 1590) was incorrect (Karamanev and Nikolov, 1992). While this discovery was "ignoring basic textbook knowledge" at the time, the peer-review process confirmed that Galileo and later Newton were wrong in that regard (mainly because the phenomena of turbulence was unknown at their respective times), and the new discovery is now part of the mainstream knowledge base (Green, 2008; Chhabra and Basavaraj, 2019). Further, the Editorial states: "A quick look at the global surface energy balance illustrates this clear picture: human primary energy consumption amounted to 595 EJ in 2021 (BP, 2022), which translates into an average heat release of 18.9 TW. When averaged over land, this yields 18.9 TW / (29% x 510x10 12 m 2) = 0.13 W m −2 (as in Jin et al., 2019), while globally, this yields 0.04 W m −2 when evenly distributed over the Earth's surface. This heat release is minute compared to the downwelling flux of longwave radiation of 346 W m −2 (Stephens et al., 2012) and the observed radiative forcing change at the top of the atmosphere of 2.7 W m−2 that can clearly be attributed to the increase in greenhouse gases (Forster et al., 2021). The greenhouse gas forcing
Global estimates of mesoscale vertical velocity remain poorly constrained due to a historical lack of adequate observations on the spatial and temporal scales needed to measure these small magnitude velocities. However, with the wide-spread and frequent observations collected by the Argo array of autonomous profiling floats, we can now better quantify mesoscale vertical velocities throughout the global ocean. We use the underutilized trajectory data from the Argo array to estimate the time evolution of isotherm displacement around a float as it drifts at 1000 dbar, allowing us to quantify vertical velocity averaged over approximately 4.5 days for that pressure level. The resulting estimates have a non-normal, high-peak, and heavy-tail distribution. The vertical velocity distribution has a mean value of (1.9±0.02)×10-6 m s-1 and a median value of (1.3± 0.2)×10-7 m s-1, but the high-magnitude events can be up to the order of 10−4 m s-1 , We find that vertical velocity is highly spatially variable and is largely associated with a combination of topographic features and horizontal flow. These are some of the first observational estimates of mesoscale vertical velocity to be taken across such large swaths of the ocean without assumptions of uniformity or reliance on horizontal divergence.
Oceanic-plates vertical tearing is seismically-identified in the present-day Earth. This type of plate tearing is frequently reported in horizontally-oblique subduction zones where transform-faulted oceanic plates are subducting (or subducted). However, the mechanisms behind vertical slab tearing are still poorly understood, thus we utilize 3D time-dependent Stokes’ flow thermo-mechanical models to further study this problem. We find that (i) the age offset of transform fault and (ii) the horizontal obliqueness of subduction fundamentally control the tearing behavior of two generic, materially-homogeneous oceanic slabs separated by a low-viscosity zone. The overriding-continental plate bends one slab first, which combined with the age-thickness difference between slabs, causes the differential sinking of them. Based on the modeling results, well-developed slabs vertical tearing would happen when the oblique angle of subduction is ≥30° or the age ratio of the secondly-bent to firstly-bent slab being ~<0.6. Quantifying the horizontal distance-vector between sinking slabs, we find that subduction at medium-low horizontal-obliqueness angles (≤30°) of young lithosphere (slabs-average ~15 Myr) tends to produce fault-perpendicular tearing. Contrastingly, old-age slabs (average ≥ 30 Myr) with medium-large obliqueness angles (~>20°) tend to produce fault-parallel tearing, related to differential slab-hinge retreat or rollback. Correlations between slabs’ (i) computed tearing horizontal-width and (ii) scaling-theory forms of their subduction-velocity differences, are reasonable (0.76-0.97). Our numerically-predicted scenarios are reasonably consistent with plate-tear imaging results from at least 4 natural subduction zones. Our modeling also suggests that continual along-trench variation in subduction dip angle may be related to a special case of oblique subduction.
The Hengill geothermal field, located in southwest Iceland, is host to the Hellisheiði power plant, with its 40+ production wells and 17 reinjection wells. Located on a tectonically active area, the field experiences both natural and induced seismicity linked to the power plant operations. To better manage the risk posed by this seismicity, the development of robust and informative forecasting models is paramount. In this study, we compare the forecasting performance of a model developed for fluid-induced seismicity (the Seismogenic Index model) and a class of well-established statistical models (Epidemic-Type Aftershock Sequence). The pseudo-prospective experiment is set up with 14 months of initial calibration and daily forecasts for a year. In the timeframe of this experiment, a dense broadband network was in place in Hengill, allowing us to rely on a high quality relocated seismic catalogue. The seismicity in the area is characterised by four main clusters, associated with the two reinjection areas, one production area an area with surface geothermal manifestations but where no operations are taking place. We show that the models are generally well suited to forecast induced seismicity, despite some limitations, and that a hybrid ETAS accounting for fluid forcing has some potential in complex regions with natural and fluid-induced seismicity.
Mountains play a vital role in shaping regional and global climate, altering atmospheric circulation and precipitation patterns. To this end, identifying projected changes in mountain precipitation is significantly challenging due to topographic complexity. This study explains how mountain precipitation could respond to rising greenhouse gases. Using a series of century-long fully coupled high-resolution simulations conducted with the Community Earth System Model, we aim to disentangle future changes in mountain precipitation in response to atmospheric carbon dioxide (CO2) perturbations. We identify five low-latitude mountain ranges with elevation-dependent precipitation response, including New Guinea, East Africa, Eastern Himalayas, Central America, and Central Andes. Those mountains are expected to have a mixture of increasing and decreasing precipitation in response to CO2-induced warming, especially over the summit and steep topography. To elucidate the mechanisms controlling future changes in mountain precipitation, we propose ‘orographic moist-convection feedback’ in which an increase in low-level relative humidity enhances local precipitation by strengthening the upward motion through moist processes for the wetting response and vice versa for the drying response. The effects of Mountain precipitation changes can be extended to hydrology and could lead to significant consequences for human societies and ecosystems.