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On the basis of S4max data retrieved from COSMIC GPS radio occultation measurements, the long-term climatology of the intensity of Es layers is investigated for the period from December 2006 to January 2014. Global maps of Es intensity show the high-spatial-resolution geographical distribution and strong seasonal dependence of Es layers. The maximum intensity of Es occurs over the mid-latitudes, and its value in summer is 2–3 times larger than that in winter. A relatively strong Es layer is observed at the North Pole and South Pole, with a distinct boundary dividing the mid-latitudes and high latitudes along the 60–80∘ geomagnetic latitude band. The simulation results show that the convergence of vertical ion velocity could partially explain the seasonal dependence of Es intensity. Furthermore, some disagreements between the distributions of the calculated divergence of vertical ion velocity and the observed Es intensity indicate that other processes, such as the vertical motions of gravity waves, magnetic-field effects, meteoric mass influx into Earth's atmosphere, and the chemical processes of metallic ions, should also be considered as they may also play an important role in the spatial and seasonal variations in Es layers.

Photocatalytic H2O2 production with H2O and O2 as resources is a promising technique. Herein, a g-C3N4@CdS (CN@CdS) Z-scheme heterojunction is prepared for photocatalytic H2O2 production with a rate of 167.5 μmol/h, which is 5.43 and 5.15 times higher than that of pure g-C3N4 and pure CdS. Photoelectronic characterization results reveal the existence of a strong built-in electric field between CdS and g-C3N4, which significantly facilitates the separation of photogenerated carriers and preserves the strong redox capacity. Density functional theory (DFT) calculations show that CN@CdS displays lower O2 adsorption energy and the H2O2 is more readily formed. This work provides a novel strategy for the design of photocatalysts with excellent H2O2 evolution efficiency.

The small-scale electron density irregularities in the ionosphere have a significant impact on the interruptions of Global Navigation Satellite System (GNSS) navigation and the accuracy of GNSS positioning techniques. The sporadic ionospheric E (Es) layer significantly contributes to the transient interruptions of signals (loss of lock) for GNSS tracking loops. These effects on the GNSS radio occultation (RO) signals can be used to derive the global location and intensity of Es layers as a complement to ground-based observations. Here we conduct statistical analyses of the intensity of Es layers, based on the scintillation index S4max from the FORMOSAT-3/COSMIC during the period 2006–2014. In comparison with simultaneous observations from an ionosonde network of five low-to-middle latitude ionosondes, the S4max indices from COSMIC, especially the small values, are linearly related to the critical frequency of Es layers (foEs). An accumulated period of less than 1 h is required to derive the short-term variations in real-time ionospheric Es layers. A total of 30.22%, 69.57% and 98.13% coincident hourly foEs values have a relative difference less than 10%, 30% and 100%. Overall, the GNSS RO measurements have the potential to provide accurate hourly observations of Es layers. Observations with S4max < 0.4 (foEs < 3.6 MHz), accounting for 66% of COSMIC S4 measurements, have not been used fully previously, as they are not easily visible in ground-based ionosonde data.

To investigate the effect of fertilization on Pb content in vegetables, pepper was planted in L1645 (the 5 influencing factors are fertilizers (N, P, K), organic fertilizers (sheep manure) and Pb2+; the 4 levels are blank, low, medium and high; a total of 16 treatments) pot orthogonal experiment. The effects of fertilizers on the growth and Pb content in various parts of pepper under Pb stress were analyzed. The results showed that: (1) The Pb content in pepper fruit ranged from 0.011 mg·kg−1 to 0.085 mg·kg−1, which did not exceed the limit value (0.1 mg·kg−1) in the National Standard for Food Safety-Limit of Contaminants in Food (GB2762-2017); (2) The effect order of fertilization on pepper fruit weight was P2O5 > sheep manure > N > K2O; The horizontal combination of factors that promoted the maximum fruit weight of pepper was N (0.15 g·kg−1), P2O5 (0.225 g·kg−1), K2O (0.15 g·kg−1) and sheep manure (9 g·kg−1); (3) The order of fertilizer effects on Pb content in pepper fruit was Pb2+ > K2O > N = sheep manure > P2O5; the factor level combination that resulted in the maximum Pb content in pepper fruits was N (0.15 g·kg−1), P2O5 (0 g·kg−1), K2O (0.45 g·kg−1), sheep manure (6 g·kg−1) and Pb2+ (350 mg·kg−1); (4) Based on the soil fertility characteristics of Urumqi, the recommended optimal fertilizer application rate was: high phosphorus fertilizer P2O5 (495 kg·hm−2), low-level potassium fertilizer K2O (330 kg·hm−2), medium-level nitrogen fertilizer N (660 kg·hm−2) (or low-level nitrogen fertilizer N (330 kg·hm−2) + high-level organic manure sheep manure (19,800 kg·hm−2), which can achieve high yield while ensuring that the Pb content in the fruits does not exceed the standard. Strengthening control of effective and reasonable fertilization methods in Urumqi agricultural land is helpful to reduce the Pb content in vegetables.

This study reports an extreme ionospheric plasma depletion event over the Eastern Pacific from postmidnight to early morning during the superstorm's recovery phase on 21 November 2003 observed by the DMSP F13, ROCSAT‐1, GRACE, and CHAMP satellites, and two ground‐based GPS receivers. The depletion and its interhemispheric geomagnetic conjugate effect occurred between ∼40°S and 40°N geomagnetic latitudes. This suggests a possible extremely long‐range flux tube connection with an apex altitude exceeding 6,000 km over the geomagnetic equator. Notably, the observed altitude for midlatitude depletions of equatorial origin in the morning is the highest ever reported. Previous studies have primarily observed the extension of equatorial plasma bubbles to middle latitudes in the post‐sunset hours. The continuous upward vertical plasma drift, supported by ROCSAT‐1 and TIE‐GCM simulations, may drive the unprecedentedly strong latitudinal extension of these midlatitude plasma depletions in the midnight‐to‐morning sector.

This study presents the observations of midlatitude plasma irregularities over Eastern Asia during a moderate magnetic storm on 16 July 2003. Multi-instrumental observations, including the ground-based ionosondes, the GNSS networks, and the CHAMP and ROCSAT-1 satellites, were utilized to investigate the occurrence and characteristics of midlatitude plasma irregularities. The midlatitude strong spread F (SSF) mainly occurred in the midnight–morning sector as observed by ionosondes over Japan during this storm. SSF was related to plasma depletions, which is also recorded by GNSS network in the form of the enhancement of the rate of total electron content (TEC) change index (ROTI). The possible mechanism for the generation of SSF is that the enhanced eastward electric fields, associated with the prompt penetration electric fields and disturbance dynamo electric fields, cause the uplift and latitudinal extension of equatorial plasma bubbles (EPBs) to generate the observed midlatitude SSF further. Meanwhile, plasma density increased significantly under the influence of this storm. In addition, other common type of spread F, frequency spread F (FSF), was observed over Japan on the non-storm day and/or at high latitude station WK545, which seems to be closely related to the coupling of medium-scale traveling ionospheric disturbances (MSTIDs) and sporadic E (Es) layer. The above results indicate that various types of midlatitude spread F can be produced by different physical mechanisms. It is found that SSF can significantly affect the performance of radio wave propagation compared with FSF. Our results show that space weather events have a significant influence on the day-to-day variability of the occurrence and characteristics of ionospheric F-region irregularities at midlatitudes.

Ionospheric sporadic E layers (Es) are intense plasma irregularities between 80 and 130 km in altitude and are generally unpredictable. Reconstructing the morphology of sporadic E layers is not only essential for understanding the nature of ionospheric irregularities and many other atmospheric coupling systems, but is also useful for solving a broad range of demands for reliable radio communication of many sectors reliant on ionosphere-dependent decision-making. Despite the efforts of many empirical and theoretical models, a predictive algorithm with both high accuracy and high efficiency is still lacking. Here we introduce a new approach for Sporadic E Layer Forecast using Artificial Neural Networks (SELF-ANN). The prediction engine is trained by fusing observational data from multiple sources, including a high-resolution ERA5 reanalysis dataset, Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation (RO) measurements, and integrated data from OMNIWeb. The results show that the model can effectively reconstruct the morphology of the ionospheric E layer with intraseasonal variability by learning complex patterns. The model obtains good performance and generalization capability by applying multiple evaluation criteria. The random forest algorithm used for preliminary processing shows that local time, altitude, longitude, and latitude are significantly essential for forecasting the E-layer region. Extensive evaluations based on ground-based observations demonstrate the superior utility of the model in dealing with unknown information. The presented framework will help us better understand the nature of the ionospheric irregularities, which is a fundamental challenge in upper-atmospheric and ionospheric physics. Moreover, the proposed SELF-ANN can make a significant contribution to the development of the prediction of ionospheric irregularities in the E layer, particularly when the formation mechanisms and evolution processes of the Es layer are not well understood.

In the mesosphere‐lower thermosphere region, atmospheric plasma components exhibit short‐term enhancements, forming sporadic E (Es) layers that impact communication systems. The prevailing theory posits that neutral wind shear is the primary driver of mid‐latitude Es layer. Here, we present neutral wind field data from the ICON/Michelson Interferometer for Global High‐resolution Thermospheric Imaging mission during 2019–2022, revealing a clear relationship between wind shear and Es layer formation in the Northern Hemisphere. Notably, the vertical ion divergence/convergence significantly impact mid‐latitude Es production. Inspired by deep learning techniques, we developed a deep learning model based on wind shear and neutral wind data, reconstructing the small‐scale morphology of Es layers. Vertical ion convergence information derived from the wind shear physical equations was found to be a key factor in enhancing model performance. Our results demonstrate that incorporating physical data from vertical ion drift improves the predictive capabilities of ionospheric irregularities artificial intelligence models, increasing the accuracy from 71.6% to 87.9%.

Photocatalytic H[sub.2]O[sub.2] production with H[sub.2]O and O[sub.2] as resources is a promising technique. Herein, a g-C[sub.3]N[sub.4]@CdS (CN@CdS) Z-scheme heterojunction is prepared for photocatalytic H[sub.2]O[sub.2] production with a rate of 167.5 μmol/h, which is 5.43 and 5.15 times higher than that of pure g-C[sub.3]N[sub.4] and pure CdS. Photoelectronic characterization results reveal the existence of a strong built-in electric field between CdS and g-C[sub.3]N[sub.4], which significantly facilitates the separation of photogenerated carriers and preserves the strong redox capacity. Density functional theory (DFT) calculations show that CN@CdS displays lower O[sub.2] adsorption energy and the H[sub.2]O[sub.2] is more readily formed. This work provides a novel strategy for the design of photocatalysts with excellent H[sub.2]O[sub.2] evolution efficiency.

Long-lived metallic ions in the Earth's atmosphere (ionosphere) have been investigated for many decades. Although the seasonal variation in ionospheric “sporadic E” layers was first observed in the 1960s, the mechanism driving the variation remains a long-standing mystery. Here, we report a study of ionospheric irregularities using scintillation data from COSMIC satellites and identify a large-scale horizontal transport of long-lived metallic ions, combining the simulations of the Whole Atmosphere Community Climate Model with the chemistry of metals and ground-based observations from two meridional chains of stations from 1975–2016. We find that the lower thermospheric meridional circulation influences the meridional transport and seasonal variations of metallic ions within sporadic E layers. The winter-to-summer meridional velocity of ions is estimated to vary between −1.08 and 7.45 m/s at altitudes of 107–118 km between 10–60∘ N. Our results not only provide strong support for the lower thermospheric meridional circulation predicted by a whole atmosphere chemistry–climate model, but also emphasize the influences of this winter-to-summer circulation on the large-scale interhemispheric transport of composition in the thermosphere–ionosphere.