Vegetation patterns often affected by the soil pH, soil compaction and human mediated disturbance. Several studies have explored how pH, compaction and human disturbance have altered the ecosystem patterns, functioning and services. These studies about semi-arid drylands, explain how lifeforms and productivity resulting from soil acidity, hardness and human disturbance in arid-land. To further enhance the understanding of this correlation, we have surveyed five different eco-system within Yookamurra Sanctuary (Murray lands of South Australia), which is protecting over 5000 hectares of epidemic vegetation and wildlife species. Data has been collected by random sampling method with 150 quadrate samples for soil pH, soil compaction, litter depth, disturbance (Animal or Human) and lifeforms within Yookamurra region. Results suggest that the impacts of pH and compaction are varying across five different ecosystems. Moreover, vehicle disturbance has greater consequences at Roadside ecosystem. These findings amend our understanding of the interaction of soil characteristics with the vegetation patterns, especially in semi-arid region, such as Yookamurra wildlife sanctuary.

Breaking-wave induced bioluminescence is a critical component of the biogeochemical process in the ocean. Understanding bioluminescence is important for monitoring red tides caused by bioluminescent microorganisms. In this study, we present the first numerical effort to quantify bioluminescent light intensity based on high-fidelity direct numerical simulations of breaking waves and a quantitative bioluminescent model. The dynamics of breaking waves are extensively validated through comparison with existing studies. We find that the time-averaged and Lagrangian-averaged shear stress saturates as surface tension effects decrease and wave steepness increases. The spatial distribution of light intensity correlates with the wave crest overturning and air bubbles generated in plunging breakers. Furthermore, we observe that the maximum light intensity asymptotically approaches the emission of single cells, suggesting the potential for cost-effective prediction models in future studies.

These are the slides used in the RBSP Online Seminar presentation (March 25, 2022), which describe ray tracing calculations to study VLF wave dynamics in the magnetosphere.

We evaluated the performance of three global evapotranspiration (ET) models using the multiple sets of LAI and meteorological data from 1982 to 2017, and investigated the uncertainty in ET simulations from the model structure and forcing data. The three ET models were the Simple Terrestrial Hydrosphere model (SiTH), Priestly-Taylor Jet Propulsion Laboratory model (PT-JPL ) and MODIS ET algorithm (MOD16). Comparing the observed with simulated monthly ET by the three models over 43 Fluxnet sites, we found that SiTH overestimates ET for forests, but it performed better than the other two models over short vegetation. MOD16 and PT-JPL models performed well for forests, but poorly in dryland biomes. At the catchment scale, all models perform well expect over some tropical and high latitudinal catchments. At the global scale, SiTH highly overestimated ET in tropics, while PT-JPL underestimated ET between 30°N and 60°N and MOD16 underestimated ET between 15°S and 30°S. This study also revealed that the estimated ET by PT-JPL were largely influenced by the uncertainty in meteorological data, while the estimated ET by SiTH and MOD16 were relatively non-sensitive to the forcing data sets. In addition, the results suggested that the long-term variations in estimated ET trend were greatly influenced by the uncertainty in LAI data.

The opacity of clouds at Alert, Canada have been shown by measurements of their infrared irradiances to change with the day-to-day solar wind input to the global atmospheric electric circuit, as well as to the inputs of global thunderstorms and magnetic storms. These cloud changes appear to be the cause of surface pressure changes in the Arctic and Antarctic that have long been observed to correlate with the solar wind sector structure. We analyze large data sets of cloud irradiances and surface pressures, and find differences in the responses to 2, 4, or more sectors per 27-day solar rotation. There are seasonal variations, with sign reversal in the summer, which we interpret as due to changing geometry of solar insolation input. The correlation coefficients that were shown to be statistically significant at near the 95% confidence level for all-year, all sector types show further increases for just winter months and for just 2-sector intervals. The phase relationship of the pressure responses compared to those of the cloud responses are consistent but not understood. There are also interannual variations, whose cause has yet to be determined. A parameterization of the potential distribution near the magnetic poles and out through the high latitude ionospheric region affected by solar wind inputs has been made, giving correlations of IR irradiance and pressure with these parameterizations stronger than with those for the IMF B alone. The effects analyzed are an indication of more extensive influences of global atmospheric electricity on cloud microphysics and cloud development.

We construct a novel Multi-Input Multi-Output Autoencoder-decoder (MIMO-AE) to capture the non-linear relationship of Southern California precipitation (SC-PRECIP) and tropical Pacific Ocean sea surface temperature (TP-SST). The MIMO-AE is trained on both monthly TP-SST and SC-PRECIP anomalies simultaneously. The co-variability of the two fields in the MIMO-AE shared nonlinear latent space can be condensed into an index, termed the MIMO-AE index. We use a transfer learning approach to train a MIMO-AE on the combined dataset of 100 years of output from a historical simulation with the Energy Exascale Earth Systems Model version 1 (E3SMv1) and a segment of observational data. We further use Long Short-Term Memory (LSTM) networks to assess sub-seasonal predictability of SC-PRECIP using the MIMO-AE index. We find that the MIMO-AE index provides enhanced predictability of SC-PRECIP for a lead-time of up-to four months as compared to Nino 3.4 index and the El Nino Southern Oscillation Longitudinal Index.

According to the traditional definition, a mosque is just a place of prayer for Muslims, but that is not the intention. It should have served as a complex, social, and cultural structure for Muslim people. Though the contemporary facts will go against this argument, it should be kept in mind that the definition of a mosque shows that it should be an organization that contributes actively to the growth of the Muslim groups in the city. This paper intends to discuss the functional approach of mosque elements and their role in contemporary time and discuss the significance of Architectural symbolism in mosque design in the Indian context.

The rheological behavior of the lithosphere is examined beneath the Northwestern (NW) Andes (Colombian). Two profiles, one on western and other on eastern of the transition area between the Upper Magdalena Valley (UMV) and the Middle Magdalena Valley (MMV), are obtained from the analysis of the earthquake distribution and the stress drop. Results are consistent with the tectonic and geodynamic context of the western region. In essence, the brittle/ductile transition of the lithospheric crust and mantle is observed, and an approximation of the lithospheric thickness is made. Moreover, the subduction phenomenon of the Nazca Plate under the South American Plate is shown. In the Eastern region, we contemplate an aseismic zone under the Eastern Cordillera below 20 km deep that makes it challenging to know the crust/mantle boundary. This seismic particularity leads us to support the hypothesis of a delamination process due to the tectonic, geological, and thermal context. Our results suggest that the earthquake dataset correlated with rheological estimations may offer a consistent interpretation of the mechanical behavior of the lithosphere.

During the abrupt changes of the near-surface (NS) field according to the end of storm oscillations (EOSO) scenario, we observe prolonged thunderstorm ground enhancements (TGE). The EOSO starts with the reduction of the lower positively charged region (LPCR) with the following falling of the near-surface (NS) electric field in the deep negative domain for ≈12 minutes. During these minutes we observe prolonged TGE and graupel fall. Afterward, the NS field returns again to a positive value, although smaller than the initial one. Finally, the field returns to fair-weather conditions. Thus, the ending phase of the storm is followed by the degradation of all 3 charged layers of a tripole.

The radar echoes from the polar summer mesopause are observed simultaneously with Digisonde, Dynasonde, and European Incoherent Scatter Scientific Association (EISCAT) very-high-frequency (VHF) radar. The irregular characteristics of sporadic E (Es) layers at altitude range of about 80–90 km observed by Digisonde at Tromsø during 2003 to 2014 are statistically analyzed with ionograms. Because the characteristics of irregular Es layers show very similar characteristics with Polar Mesosphere Summer Echoes (PMSE), Digisonde is being recommended to study PMSE-like echoes in the Arctic. The phenomenon of irregular Es layers is called as PMSE-like or PMSE-Es (Polar Mesosphere Summer Echoes-Es) and have some relationship with real PMSE. The occurrence rate (OR) of PMSE-Es shows similarity to that of PMSE, such as diurnal, day-to-day, and year-to-year variations. The discrepancies of occurrence rate variations between PMSE and PMSE-Es are discussed with the statistical results observed by Esrange VHF radar (ESRAD).

To discuss slip behaviors in shallow slow earthquake regions, we investigate source characteristics of shallow very low frequency earthquakes (VLFEs) southeast off the Kii Peninsula in the Nankai subduction zone. VLFEs are a kind of slow earthquakes and are clearly observed at frequencies below 0.1 Hz. A non-linear inversion technique for moment rate function estimation and the permanent ocean-bottom seismometer network provided us with precise locations and detailed kinematic source characteristics of shallow VLFEs. The high activity of shallow VLFEs around the western edge of the subducted Paleo-Zenisu ridge is similar to previous studies. A notable trend change in the along-dip dependency of shallow VLFE moment rates was found. Along the profile west side of the Paleo-Zenisu ridge, moment rates of shallow VLFEs increase with reaching the megathrust zone. Small-scale topographic fluctuations of the subducted oceanic plate exist along this profile, but large-scale seamount subduction has not been identified even from dense seismic surveys. Similar tendencies have been reported in tectonic tremors in the Nankai and Cascadia subduction zones. On the other hand, the opposite trend appeared along the profile with the Paleo-Zenisu ridge. Small shallow VLFEs were dominant near the summit of the Paleo-Zenisu ridge. Fracture networks or stress fields due to seamount subduction possibly impede large shallow VLFEs around the subducted seamount. Our results suggest that the large-scale heterogeneity of the upper surface of the subducted oceanic plate could control source characteristics of shallow slow earthquakes.

The time dependence of the parameter of the Gutenberg-Richter (GR) magnitude distributions is computed for correlated foreshock sequences of earthquakes, by using the geometric-growth model of earthquake focus, the magnitude distribution of correlated earthquakes and the time-magnitude correlations, derived recently. It is shown that this parameter decreases in time in the foreshock sequence, from the background values down to the main shock. If correlations are present, this time dependence and the time-magnitude correlations provide a tool of monitoring the foreshock seismic activity. We discuss a possibility of estimating the moment of occurrence of a main shock by such an analysis of a foreshock sequence. The discussion is applied to two Vrancea main shocks. The appreciable limitations of such an estimation are discussed.

A document by Abdullah Alharthi. Click on the document to view its contents.

The occurrence ratio of intracloud (IC) to cloud-to-ground (CG) discharges, which is denoted by -ratio, is the crucial parameter for the studies on the climatological differences of thunderstorm structures and the quantitative evaluation of lightning contributions to the global electric circuit. However, the latitudinal, regional, and seasonal dependences of -ratio are not fully clarified. Therefore, using optical data obtained by the JEM-GLIMS mission, we distinguished the lightning discharge type, , IC, positive CG (+CG), and negative CG (-CG) discharges, and statistically estimated the Z-ratio. We analyzed 8354 JEM-GLIMS lightning events and succeeded in identifying 4431 IC discharges, 597 +CG discharges, and 3326 -CG discharges. From this result, we calculated the -ratio and estimated its latitudinal, regional, and seasonal dependences. It is found that the -ratio is slightly higher over the continental area than the oceanic area. In addition, the average -ratio in the local summer season is higher than that in the local winter season. The clear latitudinal dependence of the -ratio is also found, which is generally comparable to the results shown in the previous studies. The estimated -ratio varies from 2.9 - 0.19 from the equator to 50º latitude, and the global mean value is 1.6. The regional dependence of -ratio derived from this study can be combined with the CG lightning data provided by the ground-based lightning detection networks to estimate the occurrence number of IC discharges. It will greatly contribute to a more accurate estimation of the total lightning currents in the global electric circuit.

• Arctic marine ecosystems experience enhanced climate stressors with differences over time and space and among models. • Trend magnitudes are projected to further increase over time for temperature increases and oxygen declines. • SSP2-4.5 emissions can avoid calcite undersaturation before 2100, but few regions can avoid aragonite undersaturation.

Previous studies have clustered and analyzed proximity sounding profiles associated with tornadic right-moving supercells. However, few have objectively determined the optimal number of clusters or identified key features driving cluster assignments. Using self-organizing maps, we group soundings based on virtual buoyancy and wind profiles. A novel recursive feature elimination reveals that virtual buoyancy at heights of approximately 0.5 km and 1.4 km (near the level of free convection) are the most significant features in this clustering, with both acting as a proxy for the potential strength of convective inhibition (CIN). The magnitude of virtual buoyancy at 4.7 km characterizes the potential maximum strength of buoyancy (convective available potential energy; CAPE). The virtual buoyancy magnitude at 9.3 km is also important, likely corresponding to the height of the equilibrium level (EL). Low-level (< 3 km) wind profiles, particularly the westerly component, also play a key role in determining cluster assignments.

This study provides a first analysis of future changes in mean and extreme precipitation over Northeast Africa and the Arabian Peninsula. To this aim, we exploited projections from ten selected CMIP6 models (in part I) under various SSP greenhouse gases emission scenarios for the mid to late 21st century. We found a north-south differentiation in future changes in total precipitation for the JF and MAM seasons, with decreases in the north and moderate increases elsewhere, although model uncertainties are high, particularly for MAM. In contrast, the JJAS and OND seasons show larger positive changes with less model uncertainty. These increases in mean precipitation will be accompanied by an increase in the intensity and frequency of extreme precipitation events. In addition, the JJAS (+6.7%) and OND (+4.5%) seasons will contribute more to cumulative annual precipitation, while the JF (-1.3%) and MAM (-9.9%) seasons will experience a reduction. Over Djibouti, where the selected models are shown to perform well, downscaled and bias-corrected CMIP6 data using the CDF-t method indicate in addition that the return period of intense precipitation events (≥ 80 mm/day) causing documented flooding will decrease from 5 years historically to 1.4 years by the end of the 21st century under the SSP5-8.5 scenario. This robust result indicates the need to strengthen flood adaptation measures in Djibouti. Furthermore, similar downscaling exercises are recommended for other sub-regions in Northeast Africa and Arabia, given the consistent trend towards higher intensity rainfall.

A document by Pratik Shukla. Click on the document to view its contents.