| 1 | Climate change attribution of the 2021 Henan extreme precipitation: Impacts of convective organization显示文摘In this study, we investigate the climate attribution of the 21·7 Henan extreme precipitation event. A conditional storyline attribution method is used, based on simulations of the event with a small-domain high-resolution cloud-resolving model. Large-scale vertical motion is determined by an interactive representation of large-scale dynamics based on the quasigeostrophic omega equation, with dynamical forcing terms taken from observation-based reanalysis data. It is found that warming may lead to significant intensification of both regional-scale(10–14% K, depending on convective organization) and station-scale precipitation extremes(7–9% K^(-1)). By comparing clustered convection organized by a localized surface temperature anomaly and squall-line convection organized by vertical wind shear, we further explored how convective organization may modify precipitation extremes and their responses to warming. It is found that shear convective organization is much more sensitive to large-scale dynamic forcing and results in much higher precipitation extremes at both regional and station scales than unorganized convection is. The clustered convection increases station-scale precipitation only slightly during heavy precipitation events. For regional-scale extreme precipitation sensitivity, shear-organized convection has a larger sensitivity by 2–3% Kthan that of unorganized convection, over a wide temperature range, due to its stronger diabatic heating feedback. For the station-scale extreme precipitation sensitivity, no systemic dependence on convective organization is found in our simulations. | Han QIN Wei YUAN Jun WANG Yang CHEN Panxi DAI Adam HSOBEL Zhiyong MENG Ji NIE | 2022 | Science China Earth Sciences2022,65,10: | 0 |
| 2 | Cretaceous integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas显示文摘The Cretaceous Period is a vital time interval in deciphering the evolutionary history of the Neo-Tethys Ocean and the convergence of different plates and blocks across the Qinghai-Tibetan Plateau.A detailed stratigraphic framework and paleogeographic patterns are the basis for understanding the evolution of the Neo-Tethys Ocean and the formation of the QinghaiTibetan Plateau.Here,the Cretaceous stratigraphy,biota,paleogeography,and major geological events in the Qinghai-Tibetan Plateau are analyzed to establish an integrative stratigraphic framework,reconstruct the paleogeography during the Cretaceous Period,and decode the history of the major geological events.The Cretaceous rocks of the Qinghai-Tibetan Plateau and its surrounding area are predominantly marine deposits,with a small amount of interbedded marine-terrestrial and terrestrial conponents.The Indus-Yarlung Tsangpo Suture Zone was responsible for the deposition of deep marine sediments dominated by ophiolite suites and radiolarian silicalite.To the south,the Tethys Himalayas and Indus Basin received marine sediments of varying depths and lithology;to the north,the Xigaze and Ladakh forearc basins are also filled with marine sediments.The Lhasa Block,Karakorum Block,western Tarim Basin,and West Burma block consist of shallow marine,interbedded marine-terrestrial,and terrestrial sediments.The Qiangtang Basin and other areas are dominated by terrestrial sedimentation.The Cretaceous strata of the Qinghai-Tibetan Plateau and its surrounding areas are widely distributed and diversified,with abundant foraminifera,calcareous nannofossils,radiolarians,ammonites,bivalves,and palynomorphs.On the basis of integrated lithostratigraphic,biostratigraphic,geochronologic,and chemostratigraphic analyses,we proposed herein a comprehensive stratigraphic framework for the Cretaceous Period of the eastern Neo-Tethys.By analyzing the Cretaceous biota of different biogeographic zones from eastern Neo-Tethys and its surrounding areas,we reconstructed the paleobiogeography of different periods of eastern NeoTethys.The Cretaceous paleogeographic evolution of the Qinghai-Tibetan Plateau and its surrounding areas can be divided into three phases:(1)gradual breakup of the Indian Plate from the Australia-Antarctica continent and the early collision phase of the Lhasa-Qiangtang blocks(145-125 Ma);(2)northward drift of the Indian Plate and the collision phase of the Lhasa-Qiangtang blocks(125-100 Ma);(3)rapid northward drift of the Indian Plate,formation of the Tarim-Tajik-Karakorum Bay,and early uplift of the Gangdise Mountains(100-66 Ma).The Indus-Tethys Himalayan biota underwent a transition from the cold-water type in the high latitudes of the southern hemisphere to the warm-water type near the equator from the Early Cretaceous to the MidCretaceous.The biodiversity and abundance of the eastern Neo-Tethys Ocean increased gradually in the Early Cretaceous,peaking in the Mid-Cretaceous,and decreased sharply during the late Late Cretaceous(late Maastrichtian).Along with the northward drift of the Indian Plate and subduction of the Neo-Tethys,the eastern Neo-Tethys and its surrounding areas experienced a series of major geological events,including the formation of the large igneous province,oceanic anoxia events,and mass extinction,etc. | Dangpeng XI Guobiao LI Shijun JIANG Xin RAO Tian JIANG Tianyang WANG Zuohuan QIN Yasu WANG Jianzhong JIA Muhammad KAMRAN Zhongye SHI Yuyang WU Panxi WANG Lixin SUN Qinggao ZENG Xiaoqiao WAN | 2024 | Science China Earth Sciences2024,67,4: | 0 |