Journal of Geophysical Research: Atmospheres

Liu, Dongxia; Qie, Xiushu; Li, Fengquan; Sun, Zhuling; Li, Haoran; Qu Zhen, Yixi; Sun, Chunfa; Wei, Lei; Zhu, Kexin; Lyu, Huimin; Tang, Guoying

doi: 10.1029/2025jd045623pmid: N/A

To get more insights into the charge structure inside thunderstorms over high plateau regions, this poses significant challenges. Based on the data from the high‐precision lightning VHF interferometer, C‐band Doppler radar and multi‐band electromagnetic field observation, this study presented the complete evolutionary characteristics of charge structure in an atypical bottom‐heavy thunderstorm producing solely intra‐cloud (IC) lightning over the Tibetan Plateau (TP). A persistent inverted dipole and a tripolar charge structure with a larger‐than‐usual lower positive charge center (LPCC) coexisted within this thunderstorm. At the initial and the sustained weak convection stages, the thunderstorm demonstrated a negative dipolar charge structure. As the convection further developed into a mature stage, an additional positive charge region appeared in the upper level, forming a tripolar charge structure with a larger LPCC at the bottom of an intense convective region. In contrast, a neighboring convective region preferentially developed the upper‐level dipole charge structure rather than forming an LPCC. The IC flashes, with a maximum of 4 fl/min, predominantly occurred as negative IC flashes originating from the lower negative dipole, while few positive IC flashes occurred between the upper dipole charge structure. The LPCC was primarily associated with positive charged graupel particles. The middle negative charge region involved substantial negative charge carried by ice crystals and snow aggregates with graupel particles acting as the charge carrier in its upper part. The upper positive charge region was mainly contributed by ice crystals and snow aggregates.

Hazem, Y.; Celestin, S.; Trompier, F.; Hobara, Y.

doi: 10.1029/2025jd045152pmid: N/A

Gamma‐ray glows (GRGs) are high‐energy events associated with thunderstorms, characterized by an enhancement of the high‐energy background radiation lasting from a few seconds to several minutes. They are typically detected near their sources by balloons, aircraft, mountain‐based observatories, or at sea level in regions where thunderstorms develop at low altitudes, such as in the western coastal regions of Japan. To investigate these events, a BGO scintillator was installed on the roof of the W‐2 building at the University of Electro‐Communications in Chofu, Tokyo, in the summer of 2023. In February 2024, a weak GRG was detected using a new statistical approach that combines Gaussian convolution with Bayesian inference and Continuous Wavelet Transform. This method demonstrates strong potential for extracting weak signals buried in noise, offering a powerful tool for detecting GRGs of low intensity. Beyond individual detections, it provides a new way to reveal events that would otherwise remain unnoticed due to their low intensity, thereby opening new perspectives for studying the occurrence rate and rarity of GRGs.

Duan, Chunhui; Han, Cunbo; Hu, Wei; Liu, Jiawei; Ma, Yaoming

doi: 10.1029/2026jd046444pmid: N/A

The global rapid expansion of photovoltaic (PV) power plants has drawn considerable attention to their impacts on land surface temperature (LST), which is a crucial indicator of surface energy balance. However, previous studies mainly focused on individual plants or limited regions. In this study, the effects of ground‐mounted PV power plants on LST across China have been investigated in detail. The analysis integrates Thermal and Reanalysis Integrating Moderate‐resolution Spatial‐seamless (TRIMS) LST with the land component of the fifth generation of European ReAnalysis (ERA5‐Land), using a random forest regression model combined with the Shapley additive explanations (SHAP) method. The results show that PV power plants generally induce daytime warming (0.10°C) and nighttime cooling (−0.09°C) effects on LST relative to surrounding areas, and produce a nearly negligible daily warming (0.01°C) effect. Such effects are found in vegetated areas (cropland, woodland, grassland), particularly in woodlands. Daytime warming and nighttime cooling effects are the strongest in summer (0.29°C) and winter (−0.13°C), respectively. The daily effect is warming in summer (0.12°C) but cooling in winter (−0.05°C). Albedo, Normalized Difference Vegetation Index (NDVI), sensible heat flux, latent heat flux, wind speed, and downward shortwave radiation are identified as the key factors influencing LST differences between PV power plants and their surrounding areas (ΔLST). The contributions of these factors vary in both diurnal and seasonal cycles. These findings elucidate the local‐scale climate feedback initiated by PV installations through land‐atmosphere interactions, offering critical insights for the sustainable deployment of solar energy.

Wu, Wenhui; Gao, Yaqin; Yan, Rusha; Zhu, Shuhui; Jing, Sheng'ao; Wang, Qian; Huang, Dan Dan; Zhou, Wenxin; Lou, Shengrong; Shen, Jiandong; Huang, Cheng; Fu, Qingyan; Zhao, Yue; Li, Chenxi; Wang, Hongli

Roldán‐Henao, Natalia; Li, Zhanqing; Su, Tianning; Fan, Jiwen; Yorks, John

doi: 10.1029/2025jd045263pmid: N/A

Several mechanisms have been proposed for the aerosol invigoration effect. Although their principles are well established, their actual magnitudes and roles in cloud development remain uncertain and debatable. This uncertainty partly stems from observational‐based studies, in which it has been challenging to separate the co‐variability between aerosols and meteorology. Addressing this problem requires large data samples. To this end, this study employs the Atmospheric Radiation Measurement data set expanding to 16 years (some up to 17 years, compared to 10 years in previous work) in the U.S. Southern Great Plains. It also conducts a more careful and rigorous analysis to isolate the influences of convective available potential energy (CAPE) and synoptic patterns to address a previously raised concern. We incorporated a new key process affecting aerosol‐cloud interaction: cloud‐surface coupling. The state/degree of the coupling relationship turns out to play an important role in the invigoration effect. Our analysis reinforces earlier findings of a robust positive relationship between cloud thickness and aerosol loading across CAPE percentiles—but only under cloud‐surface coupled conditions. The increase in cloud thickness with aerosol loading is most pronounced in coupled clouds with high CAPE and bases below 1 km. Coupled clouds with bases below 1 km thicken between 1 and 4 km, depending on the CAPE percentile. Decoupled clouds show no such systematic changes. Synoptic patterns also lead to different strengths of the invigoration effect. Clean and polluted air masses are predominantly associated with northerly and southerly winds, respectively, with a stronger invigoration effect in cleaner air masses.

Ehret, Antoine; Turquety, Solène; Da Silva, Anderson; George, Maya; Hadji‐Lazaro, Juliette; Franco, Bruno; Clarisse, Lieven; Coheur, Pierre‐François; Clerbaux, Cathy

doi: 10.1029/2025jd045500pmid: N/A

Wildfires emit significant greenhouse gases and pollutants. Extreme fires disperse smoke plumes over long distances, necessitating a deeper understanding of their source regions and variability. This study introduces a plume back‐trajectory algorithm using carbon monoxide (CO) and peroxyacetyl nitrate satellite observations from the Infrared Atmospheric Sounding Interferometer (IASI) mission to analyze fire plumes in the extra‐tropical Northern Hemisphere between June and October for the 2008–2023 period. The approach leverages daily satellite data for extensive spatial coverage with minimal computational effort to detect and track extreme fire plumes. The detection of extreme events is validated using IAGOS CO data and the estimated plume origin is compared with FLEXPART back‐trajectories. In regions exhibiting intense fire activity (Boreal North America, Temperate North America, Eastern Boreal Asia (EBOAS)) or located downwind (North Atlantic, Europe), the average total column of CO and PAN increased between 2008–2023 and 2017–2023. The identification and analysis of plumes indicate that this increase is primarily driven by the larger spatial extent of the plumes, rather than by higher total CO and PAN within them. The IASI‐based back‐trajectory algorithm reveals that 51 % of plumes identified between June and October 2008–2023 originate from Boreal and Temperate North America and EBOAS. The number of plumes from these regions increased by up to 47 % between 2017 and 2023 in comparison to 2008–2023. 45 % of plumes observed in Europe come from North America. Despite limitations, this method effectively estimates CO + PAN plume trajectories and origins using satellite observations, providing a rapid tool for identifying pollution plume sources.

Kühner, T.; Völker, G. S.; Achatz, U.

doi: 10.1029/2025jd045506pmid: N/A

Conventional gravity‐wave (GW) parameterizations neglect three aspects of GW dynamics. Instead of momentum and entropy fluxes they use Eliassen‐Palm fluxes, thereby neglecting the possibility that resolved flow are not in geostrophic and hydrostatic balance. They neglect the transience of the GW field and of the resolved flow, by determining at every time step equilibrium profiles of GW fluxes that would result if the vertical GW propagation were instantaneous. Moreover, they also do not take into account lateral GW propagation and horizontal GW fluxes. Because the prognostic GW model MS‐GWaM does not need to make these assumptions, it has been used in the global weather and climate code ICON to investigate their consequences for the simulation of monthly mean zonal mean flows and of solar tides. All three aspects are found to influence the simulation results significantly. The mean circulation in the mesosphere and lower thermosphere is affected at all latitudes and in the stratosphere as well. This together with the directly modified GW forcing leads also to significant differences in the migrating and nonmigrating components of solar tides. Comparisons with tides retrieved from satellite data are most favorable if both aspects are taken into account. This argues for a correspondingly generalized treatment of GW dynamics in their parameterization, as an efficient alternative to GW permitting simulations.

Marcos, T.; de la Torre, A.; Alexander, P.; Geldenhuys, M.; Hierro, R.

doi: 10.1029/2025jd044692pmid: N/A

In the context of the SOUTHTRAC (Southern Hemisphere Transport, Dynamics, and Chemistry) campaign, carried out by a specialized aircraft in the southern Patagonia, one of the flights was analyzed using a spectral rotary method in order to understand the vertical energy transport of gravity waves (GWs) above the Antarctic Peninsula. The interpretations and capabilities of the rotary method were first tested using a set of synthetic waves. The importance of the flight chosen for this study was due to the high resolution data obtained over the Antarctic Peninsula and southern Patagonia. The most valuable data due to its wide observational window, collected by the on‐board ALIMA (Airborne LiDAR for Middle Atmospheric Research) LiDAR, provided temperature profiles roughly from 20 to 70 km height; and a set of sensors that registered the wind in three dimensions, pressure, and temperature at flight level. A set of large amplitude gravity waves were detected by ALIMA, one of them likely emitted during geostrophic adjustment in the vicinity of a jet near the Andes, and a mountain wave generated over the Antarctic Peninsula. Finally, the GROGRAT (Gravity‐wave Regional or Global Ray Tracer) model was implemented, which combined with additional tools and analysis allowed to infer the trajectory of the wave detected in the Drake Passage.

Chen, Zhixiong; Luo, Renjie; Liu, Jane; Qie, Xiushu; Bian, Jianchun; Jiang, Rubin; Li, Dan; Bai, Zhixuan; Zhang, Hongbo; Xie, Yunhui; Zeng, Xiangting; Su, Jiajia; Yang, Mengmiao; Shu, Lei; Cheng, Xugeng

Saito, Hiroaki; Yasukouchi, Yusuke; Hiratsuka, Takamasa; Yamamoto, Masa‐yuki

doi: 10.1029/2025jd045676pmid: N/A

We present the first direct detection of firework‐generated infrasound in the upper mesosphere and lower thermosphere using a rocket‐borne sensor. A wideband capacitive differential pressure sensor (INF03D) was installed on board the MOMO3 sounding rocket, a privately developed vehicle launched from Taiki, Hokkaido, Japan, in May 2019, which reached a maximum altitude of ∼113 km. Ten spherical fireworks were launched from the ground before and after liftoff to provide temporally tagged acoustic sources. Here, T $T$ denotes the rocket launch time (T=0 $T=0$ s), and all time stamps are given relative to launch unless otherwise stated. Three‐dimensional ray‐tracing simulations were performed with four atmospheric profile sets (NRLMSISE‐00/HWM14, JAWARA, ERA5, and MERRA‐2) to evaluate spatiotemporal intersections between acoustic ray paths and the rocket trajectory. Four distinct pressure transients with Hilbert‐envelope amplitudes of 1.0–2.8 Pa were detected at 50–76 km during ascent, falling within the modeled arrival windows for the T‐30 s and T‐90 s shots. In addition, two weak peaks (∼3.8 mPa each) were observed at 106–109 km during descent, coinciding with a predicted intersection window and classified as marginal hits due to their limited signal‐to‐noise ratios (SNR). Additional ascent‐phase transients around T+170–T+185 s lacked corresponding ray–rocket intersections, suggesting unmodeled propagation or non‐firework sources, and telemetry loss after T+282 s prevented evaluation of late‐descent signals. These findings demonstrate that 0.1–2 Hz infrasound from near‐surface explosions can propagate to over 100 km altitude and that rocket‐borne sensors provide an effective platform for in situ acoustic measurements in the middle and upper atmosphere.