首页期刊导航|Climate dynamics: Observational, theoretical and computational research on the climate system
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Climate dynamics: Observational, theoretical and computational research on the climate system
Springer-Verlag
Climate dynamics: Observational, theoretical and computational research on the climate system

Springer-Verlag

0930-7575

Climate dynamics: Observational, theoretical and computational research on the climate system/Journal Climate dynamics: Observational, theoretical and computational research on the climate systemSCIISTP
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    High PM2.5 episodes in Seoul, Korea, associated with Siberian High intensity

    Ka-Young KimChang-Hoi HoHye-Ryun OhWoosuk Choi...
    1.1-1.20页
    查看更多>>摘要：Abstract The Siberian High (SH) dominates the wintertime atmospheric circulation over East Asia which strongly modulates the concentration of particulate matter ≤ 2.5 μm in diameter (PM2.5) in the region. While the SH exhibits considerable day-to-day variations, previous studies have focused on its seasonal and interannual effects rather than its short-term influence on PM2.5 concentrations. This study investigates the link between the evolution of atmospheric circulation associated with the changes in the SH intensity and the occurrence of high PM2.5 concentrations (≥ 35 µg m−3) in Seoul, Korea. Using a hierarchical clustering method, the synoptic patterns associated with 94 high-PM2.5 episodes in Seoul during the winters of 2008–2022 are classified into two groups based on the intensity of SH: 49 episodes with strong SH and 45 episodes with weak SH. Each SH pattern can induce high-PM2.5 episodes over distinct daily timescales through different dynamical and thermodynamical processes in the upper and lower troposphere. The strong SH is transformed into a migratory anticyclone over Korea, reducing wind speeds in the lower troposphere. These conditions suppress atmospheric ventilation and enhance dynamic stability, providing a favorable environment for rapid accumulation of PM2.5 near the surface within two days. During the weak SH events, the anticyclonic flow in the upper troposphere increases air temperatures in the mid-to-lower troposphere, resulting in increased low-tropospheric thermal stability. Air pollutants cannot disperse into the upper atmosphere and gradually accumulate to high PM2.5 levels over a period of four days. This study highlights that the development of atmospheric circulation in both strong and weak SH patterns plays an important role in the air quality degradation in Seoul through different temporal characteristics. These SH-driven atmospheric circulations provide valuable insights for improving forecast accuracy and enabling targeted emission control strategies based on the expected timing of pollution episodes.
      原文链接:
    • NETL
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    • Springer Nature

    Monthly variations of the spring greenness response across boreal Eurasia to the preceding wintertime northern annular mode during 1982–2022

    Jing LiWeiming ZengRuichen LinZhiqing Xu...
    1.1-1.19页
    查看更多>>摘要：Abstract The Northern Annular Mode (NAM) represents the primary form of atmospheric variability in the northern extratropics, significantly influencing the climate in the northern mid-high latitudes. In this study, the linkages between the previous wintertime (December-January-February-March) NAM (WNAM) and springtime vegetation growth across North Eurasia (NEUA), as measured by the normalized difference vegetation index (NDVI), were investigated. Results indicate vegetation cover tends be higher than normal over Europe (western Siberia) in March (May) during or after WNAM’s positive phase, and the opposite for WNAM’s negative phase. However, reduced April vegetation growth across central NEUA is apparent after both the positive and negative phases of the WNAM. In March, the WNAM anomaly excites a Rossby wave from the North Atlantic to western NEUA, generating anomalous high pressure and an anticyclone across western NEUA during WNAM’s positive phase. Consequently, there is a notable increase in 2-m air temperature in the region, which favors vegetation growth. In April, a North Atlantic tripole pattern of sea surface temperature (SST) anomalies preserves the previous WNAM signal and triggers atmospheric wave trains from the North Atlantic to central NEUA after WNAM’s positive phase. This in turn leads to anomalous low pressure and increased cloudiness in central NEUA, which results in a reduction in temperature and solar radiation, thereby inhibiting vegetation growth in the region. However, in April after WNAM’s negative phase, positive snow cover anomalies reduce the turbulent heat flux to the south of Lake Baikal, altering the temperature gradient and triggering an anomalous cyclone, which also leads to reduced temperatures and solar radiation, thereby suppressing vegetation growth in central NEUA in April. WNAM’s impact on vegetation in May mirrors the physical processes after its positive phase in April, particularly in connection with the North Atlantic tripole SST. The findings offer new insights into WNAM’s impact on climate and vegetation in the northern mid-high latitudes, suggesting that WNAM could serve as a reliable predictor for spring vegetation growth anomalies in NEUA.
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    • Springer Nature

    Skill comparisons and physical drivers of multi-decadal rapid warming of Indian Ocean in CMIP6 models

    Zhanqing ZhangXinying GuoShangmin LongHuan Jiang...
    1.1-1.18页
    查看更多>>摘要：Abstract Observations indicate that the upper-layer Indian Ocean (IO) has experienced multi-decadal rapid warming with a rate of approximately 0.18 °C/decade since the early 1990s. The ability of Coupled Model Intercomparison Project Phase 6 (CMIP6) models to reproduce this rapid warming is essential but not well assessed, and the underlying physical drivers remain unclear. In this study, we examine the performance of 17 CMIP6 models in simulating this observed rapid warming in the IO, investigate the physical drivers responsible for the IO warming, and explore the origin of the biases in the CMIP6 models. We find that the IO warming in a majority of the CMIP6 models is stronger than that in observations, and the warming patterns in these models display significant disparities compared to observations. Four regions are important in determining the ability of CMIP6 models in reproducing the observed warming pattern. The CMIP6 models basically overestimate the warming trends in the western and northwestern IO but underestimate the warming trends in the eastern tropical and southern IO. Model skill is quantified using the Taylor diagram and Taylor skill score. It seems that the sea surface heat flux accounts for the rapid IO warming while the heat advection damps the warming. We suggest that the heat advection, especially the vertical heat advection, plays a crucial role in determining the inter-model spread and bias relative to observations, and the enhanced zonal heat transport associated with the Indonesian Throughflow and the decreased vertical heat advection led to the rapider warming after the 1990s than before.
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    • Springer Nature

    Impact of driving factors on drought propagation: perspectives on rainfall deficit and excessive evaporation

    Shuang ZhuWenying HuangYan WeiJun Guo...
    1.1-1.24页
    查看更多>>摘要：Abstract Current research lacks studies on the distinct risk mechanisms associated with different types of meteorological droughts, as well as the threshold values that trigger subsequent drought events. This study aims to address this gap by investigating the propagation processes of rainfall deficit-induced and excessive evaporation-induced meteorological droughts, particularly in their impacts on hydrology and agriculture in the Middle and Lower Reaches of the Yangtze River (MLYR) from 1982 to 2020. This is the first study to construct response relationship models for single-factor and multi-factor-driven characteristics of two distinct types of drought events by employing a spatiotemporal matching method for events with causal relationships. Using multidimensional Copula functions, the models were developed to capture the complex dynamics of these drought events. Additionally, Bayesian networks were integrated to calculate the threshold values that trigger varying levels of hydrological and agricultural droughts resulting from two types of meteorological droughts. The results found that the rainfall-deficit-induced meteorological droughts was considered more crucial for triggering moderate and severe hydrological droughts. By evaluating the combined impacts of multiple initiating drought characteristics, this study measured the conditional probabilities for triggering moderate, severe, and extreme hydrological and agricultural drought events. The findings indicated that when the target drought manifests as hydrological drought, the risk of rainfall deficit-induced meteorological drought transitioning to hydrological droughts is higher in the MLYR compared to excessive evaporation-induced meteorological droughts. Conversely, when the target drought is agricultural, the risk is higher for excessive evaporation-induced meteorological droughts. This study is important for understanding the disaster-causing mechanism and disaster-causing capacity of different types of meteorological droughts.
      原文链接:
    • NETL
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    • Springer Nature

    Dominant modes of interannual winter SAT covariability between the Arctic and the Tibetan Plateau: spatio-temporal structures and dynamical linkages

    Ying GaoXuguang SunXiu-Qun YangZhou Fang...
    1.1-1.19页
    查看更多>>摘要：Abstract As two highly sensitive climate zones in the world, the Arctic and Tibetan Plateau (TP) regions respectively exhibit significantly uneven spatial variability in surface air temperature (SAT) and greatly influence the Eurasian climate on the interannual timescale. However, despite the synchronized warming trends in these two regions, their interannual spatio-temporal connection remains unclear. In this study, we applied the singular value decomposition (SVD) method to ERA5 wintertime surface air temperature anomalies to explore the dominant modes of SAT covariability between the Arctic and TP. We identified two major interannual modes: the dipolar Arctic-uniform TP (DA-UTP) and the quadrupolar Arctic-dipolar TP (QA-DTP), which together explain 82% of their covariance. The DA-UTP mode resembles the negative phase of the Arctic Oscillation, characterized by a hemispheric-scale pattern of “warm northern North America—cold northern Eurasia—warm TP”, while the QA-DTP mode exhibits a meridional teleconnection in the eastern hemisphere, featuring “warm Barents and Kara Seas—cold Eurasia—warm southern TP”. Both modes primarily draw energy from the North Atlantic Ocean and affect East Asian through the atmospheric Rossby wave train. The corresponding North Atlantic SST anomalies display a tripolar distribution, with the center of the negative SST gradient anomaly in the second mode shifted southward compared to the first. These two climate modes further modulate synoptic and sub-seasonal-to-seasonal winter temperature anomalies in Eurasia by altering the hemispheric-scale temperature gradient. The findings of this study contribute to a deeper knowledge and understanding of the interannual spatial and temporal relationships of wintertime surface temperature anomalies between the Arctic and TP.
      原文链接:
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    • Springer Nature

    Emergence of positive IOD-like warming pattern driven by greenhouse gases and anthropogenic aerosols during the recent four decades

    Shengyao XinLu DongLixin WuFengfei Song...
    1.1-1.17页
    查看更多>>摘要：Abstract Most climate models project a positive Indian Ocean Dipole-like (pIOD-like) warming pattern in the tropical Indian Ocean (TIO), featuring stronger warming in the west than the east under global warming. However, it is still unclear whether this warming pattern has emerged in observations. Here, based on observational products, Coupled Model Intercomparison Project Phase 6 (CMIP6) experiments, including all forcing and single-forcing simulations, as well as Pacific and Atlantic pacemaker experiments, we found that the TIO features a pIOD-like warming pattern in observations during 1979–2020, confirmed by changes in atmospheric circulation and convection. External forcing makes a major contribution to the observed pIOD-like warming pattern, with greenhouse gases (GHGs) contributing the most through the weakening of Walker circulation. Anthropogenic aerosols also contribute to the pIOD-like pattern, mainly through the local ocean-atmosphere interaction driven by the increased aerosol emissions from South Asia. The CMIP6 inter-model uncertainty in the simulated pIOD-like warming pattern is related to the anomalous zonal winds over the TIO, not with the remote forcing from the Pacific Ocean, highlighting the importance of processes internal to the Indian Ocean. Before the satellite era (1920–1978), although GHG forcing favors the pIOD-like warming pattern but with weaker trend, the increased aerosol emissions from Europe and North America offset the contribution of GHGs via influencing the inter-hemispheric temperature contrast, resulting in an insignificant pIOD-like warming pattern under external forcing and in observations. This study highlights the importance of the combined effects of GHGs and anthropogenic aerosols in the recent emergence of pIOD-like warming pattern.
      原文链接:
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    • Springer Nature

    Extreme precipitation analysis in Central Asia based on the two-step kappa approach under global change

    Kaiya SunPeng YangJun XiaHeqing Huang...
    1.1-1.14页
    查看更多>>摘要：Abstract The complexity of terrain and climate, coupled with constraints in materials collection and analysis methods, has resulted in a lack of systematic research on extreme precipitation events in Central Asia (CA), which poses challenges to the sustainable development of water resource systems and emergency management. Hence, this study explored the spatial distribution, frequency, and intensity features of extreme precipitation events in CA employing a two-step Kappa approach integrated with generalized Pareto distributions (GPD), binomial distributions, and Global Land Data Assimilation System (GLDAS) data. The results show that: (1) there were significant spatial distribution differences in parameters estimated by the two-step Kappa approach of extreme precipitation at different time scales in CA, with the southeastern mountains performing exceptional behavior and showing a greater susceptibility to extreme precipitation events; (2) extreme precipitation exhibited an inverse relationship with event rarity, characterized by high frequency and low intensity in northern and central CA, while there was low frequency and high intensity (e.g., 99% of extreme precipitation events exceeding 300 mm per day) in the eastern plateau; (3) extreme precipitation in CA exhibited seasonal differences, with the widest summer precipitation range in the northern Kazakhstan, yet predominantly concentrated in the southeastern CA in other seasons. The study is significant for gaining deeper insights into the spatial distribution, future trends, and water risk emergency management of extreme precipitation events in CA.
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    • NETL
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    • Springer Nature

    Novel monsoon indices based on vector projection and directed angle for measuring the East Asian summer monsoon

    Yinan YangJianping Li
    1.1-1.22页
    查看更多>>摘要：Abstract This study presents a novel framework within a unified monsoon coordinate system for quantifying variability of the East Asian Summer Monsoon (EASM) through integrating two new concepts: the monsoon vector projection (MVP), quantifying monsoon intensity and directed angle (DA), capturing monsoon directional variability. The newly introduced MVP and DA indices based on the framework show very significant correlations with summer precipitation in the middle-lower Yangtze River, much more surpassing previous EASM indices and can also capture the Meiyu–Changma–Baiu belt's spatial pattern more clearly and comprehensively. Strong EASM years are characterized by convergence, indicated by the MVP along the Meiyu front, coupled with anomalous cyclonic shear, reflected by the DA deflection, being associated with wetter conditions in the Meiyu belt and the westward extension and southward shift of the Western Pacific Subtropical High, alongside drier conditions in northern China, which together manifest the north–south precipitation dipole pattern. In contrast, weak EASM years exhibit the opposite characteristics of strong EASM years. Moreover, this paper also proposes a creative conception—the Rossby wave ray flux (WRF), which can reflect the pathway of Rossby wave activity of the Indo-Asian-Pacific teleconnection very well. The monsoon coordinate system can be extended to other monsoon domains and could provide valuable insights for better capturing variabilities of monsoons and understanding their relationships with other climate factors in the future. Meanwhile, the WRF may provide a new tool for diagnosing local activity and propagation direction of Rossby waves.
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    • NETL
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    • Springer Nature

    The key role of abnormal Vortex Street-like system in the Tibetan plateau’s wake in modulating extreme June-July rainfall events over Eastern China (2020 and 2024)

    Qi LiuCongbin FuZhongfeng Xu
    1.1-1.16页
    查看更多>>摘要：Abstract Eastern China has frequently experienced extreme June-July rainfall events, such as those in June–July 2020 and June–July 2024, which led to severe flooding, resulting in significant economic losses and losses of life. Previous studies have explored the event’s causes. Our research indicates that these rainfall events are significantly influenced by a Vortex Street-Like system in the Tibetan Plateau’s wake (TPVSL, a phenomenon in the textbook). Using daily reanalysis and precipitation observation data, we examined the anomalous circulation associated with extreme rainfall events from the perspective of the TPVSL. Our findings reveal that the TPVSL provided a background field for ~ 80% of the rainfall during these events. In both events, the TPVSL intensity exhibited abnormal enhancement, which was related to the abnormally strong upstream westerly. However, notable differences were observed between the two events, the propagating line of the TPVSL exhibited slower northward movement and an almost east-west orientation in June-July 2020. In contrast, the north-south latitudinal change in the propagating line of the TPVSL was near normal in June-July 2024, with the line oriented southwest-northeast. These differences were related to abnormal activities in the downstream westerly belt and Western Pacific Subtropical High. Furthermore, during both events, the vortex propagation speed and shedding period remained close to normal levels. Our study provides new insight into East Asian summer climate anomalies by examining vortex street dynamics and highlights the importance of understanding TPVSL to mitigate flood disasters.
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    • Springer Nature

    Interactions between subpolar and subtropical jet streams lead to extreme rainfall events over the North Indian Subcontinent in June 2013 and July 2023

    Dipanjan DeyLigin JosephArkaprava RayRobert Marsh...
    1.1-1.17页
    查看更多>>摘要：Abstract North Indian Subcontinent (NIS) is prone to disastrous and life-threatening floods during the summer monsoon period primarily due to its close proximity with the Himalayan foothills. Indian Meteorological Department (IMD) reported that during June 13–19, 2013, the Uttarakhand state in North India experienced a cumulative total of 322 mm rainfall, a 847% weekly departure against the long-term average rainfall (1971–2020) of 34 mm. After a decade, another state in the same region, Himachal Pradesh, received an unprecedented 223 mm of rainfall in just 4 days, viz 7–11 July 2023, a 436% deviation from the cumulative climatological rainfall of 41.6 mm for 4 days (July 7–11). It is shown that the atmospheric water vapor is transported towards NIS by two monsoon low pressure systems during the June 2013 event. In contrast, during the July 2023 flood, the monsoon trough shifted southward, resulting in the moisture transport pathway predominantly over the northern Indian Ocean. In conjunction, it was shown through upper-level air tracing that southward movement of the subpolar jet stream creates a trough in the subtropical jet stream, which intrudes along the western boundary of NIS, leading to upper-level divergence. This pattern was observed in both flood events. By leveraging the mass-conserving nature and unique capability of a Lagrangian tracing model to track atmospheric water backward in time, our novel analysis of the 2023 flood reveals that two evaporative sources near Madagascar and the western Indian Ocean were key contributors, and inland evaporation played a comparatively lesser role as compared to the 2013 case. The Bay of Bengal served primarily as a vapor transport pathway rather than a direct moisture source for both events. This novel Lagrangian approach, which exposes separate drivers of extreme monsoon rainfall, upstream and at lead times of days-weeks, has the potential to be used more extensively and operationally.
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    • NETL
    • NSTL
    • Springer Nature