地球科学最新文献

Natural hazards like thunderstorms or lightning can cause loss to the economy and lives, especially in major urban centers. A long-term analysis of pre-monsoon thunderstorm rainfall and lightning, as well as thermodynamic indices like Convective Available Potential Energy, George’s K-Index, and Total Totals Index, has been performed over the major urban hubs of India, i.e., Delhi, Hyderabad, Chennai, Bangalore, Mumbai, Pune, Kolkata, and Ahmedabad. For this purpose, the study utilized IMDAA and ERA5 datasets correspondingly for rainfall and thermodynamic indices for the period from 1980 to 2020, and TRMM and WGLC datasets for lightning observations for periods from 1999–2009 (PRE10) to 2010–2020 (POST10) respectively. For most cities, the quadri-decadal trend of pre-monsoon precipitation increased except for Kolkata and Ahmedabad, where a decrease was noticed. However, the trend over Chennai was realized to be significant through the Mann-Kendal test. There is an east–west contrast in the amount of pre-monsoon precipitation between the cities located in the eastern and western parts of the country. The spatial distribution indicates that rainfall has considerably increased in the boundary regions of the cities and the associated non-urban neighborhoods in recent times. This urban boundary contrast is more prominent in the case of Hyderabad, Delhi, and Pune, since rainfall shows an increase of > 25 mm in the boundary regions in the recent years. The spatiotemporal analysis of lightning shows an increasing trend in most of the cities, where it is statistically significant over Delhi, Hyderabad, and Kolkata in the POST10 period. For Kolkata, the trend is more profound with a considerable Sen’s slope value (~ 0.04) compared to other cities. Most of the flashes are observed in the boundary regions of the cities rather than their center. The analysis also advocates KI and TTI to play a considerable role in the initiation of pre-monsoon thunderstorms compared to CAPE.

The Gravity Recovery and Climate Experiment (GRACE) and GRACE follow-on have enabled basin- to continental-scale monitoring of global water storage, cryospheric mass change, and sea-level variation since 2002. Yet key challenges remain in coarse spatial resolution, signal leakage, and dependence on auxiliary models. This review synthesizes research progress and frontiers by tracking thematic evolution, methodological innovation, and interdisciplinary integration. Analyzing 2417 publications from Web of Science Core Collection (2015–2025) with CiteSpace, we mapped publication patterns, research hot spots, collaboration networks, and emerging frontiers. Three main findings stood out: (1) a progression from “mission milestones” to “methodological innovation” and “cross-disciplinary expansion,” with terrestrial water storage, gravity inversion, and water balance as core themes, while machine learning and multi-source fusion as recent foci; (2) a global collaboration network dominated by the National Aeronautics and Space Administration, the Chinese Academy of Sciences, and the German Research Centre for Geosciences, showing strong cooperation among North America, Europe, and China but limited engagement elsewhere; and (3) expansion in interdisciplinary areas, such as carbon cycle–hydrology coupling and the water–energy–food nexus, underscoring GRACE’s role in sustainability. This study outlines priorities to advance GRACE applications through mission continuity, AI-based modeling, and high-resolution regional analysis, contributing to global change research and water resource management.