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Atmospheric and oceanic Science Letters 2025年第1期18卷 24-31页

作者： Tiantian Tang Jiaying He Huihang Sun Jingjia Luo Institute for climate and Application Research(ICAR)/Key laboratory of Meteorological Disaster Nanjing University of Information Science and TechnologyNanjingChina

A remarkable marine heatwave,known as the“Blob”,occurred in the Northeast Pacific ocean from late 2013 to early 2016,which displayed strong warm anomalies extending from the surface to a depth of 300 *** study employed two assimilation schemes based on the global climate Forecast System of Nanjing University of Information Science(NUIST-CFS 1.0)to investigate the impact of ocean data assimilation on the seasonal prediction of this extreme marine *** sea surface temperature(SST)nudging scheme assimilates SST only,while the deterministic ensemble Kalman filter(EnKF)scheme assimilates observations from the surface to the deep *** latter notably improves the forecasting skill for subsurface temperature anomalies,especially at the depth of 100-300 m(the lower layer),outperforming the SST nudging *** excels in predicting both horizontal and vertical heat transport in the lower layer,contributing to improved forecasts of the lower-layer warming during the *** improvements stem from the assimilation of subsurface observational data,which are important in predicting the upper-ocean *** results suggest that assimilating ocean data with the EnKF scheme significantly enhances the accuracy in predicting subsurface temperature anomalies during the Blob and offers better understanding of its underlying mechanisms.

关键词： Seasonal forecast ocean data assimilation Marine heatwave Subsurface temperature

Optimizing the key parameter to accelerate the recovery of AMOC under a rapid increase of greenhouse gas forcing

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Atmospheric and oceanic Science Letters 2025年第1期18卷 39-45页

作者： Haolan Ren Fei Zheng Tingwei Cao Qiang Wang International Center for climate and Environment Science(ICCES) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina College of oceanography Hohai UniversityNanjingChina CAS Key laboratory of ocean Circulation and Waves Institute of OceanologyChinese Academy of Sciences and Pilot National Laboratory for Marine Science and Technology(Qingdao)QingdaoChina

Atlantic Meridional Overturning Circulation(AMOC)plays a central role in long-term climate variations through its heat and freshwater transports,which can collapse under a rapid increase of greenhouse gas forcing in climate *** studies have suggested that the deviation of model parameters is one of the major factors in inducing inaccurate AMOC *** this work,with a low-resolution earth system model,the authors try to explore whether a reasonable adjustment of the key model parameter can help to re-establish the AMOC after its *** a new optimization strategy,the extra freshwater flux(FWF)parameter is determined to be the dominant one affecting the AMOC’s *** traditional ensemble optimal interpolation(EnOI)data assimilation and new machine learning methods are adopted to optimize the FWF parameter in an abrupt 4×CO_(2) forcing experiment to improve the adaptability of model parameters and accelerate the recovery of *** results show that,under an abrupt 4×CO_(2) forcing in millennial simulations,the AMOC will first collapse and then re-establish by the default FWF parameter ***,during the parameter adjustment process,the saltier and colder sea water over the North Atlantic region are the dominant factors in usefully improving the adaptability of the FWF parameter and accelerating the recovery of AMOC,according to their physical relationship with FWF on the interdecadal timescale.

关键词： Recovery of AMOC 4×CO_(2)forcing Key parameter Parameter estimation Data assimilation Machine learning

The super-cycle of the global land-monsoon system

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National Science Review 2024年第5期11卷 107-109页

作者： Yongyun Hu laboratory for climate and ocean-atmosphere studies Department of Atmospheric and Oceanic Sciences School of Physics Peking University

The modern monsoon system consists of six regional monsoons [1]. These regional monsoons demonstrate coherently annual variations of precipitation and atmospheric circulation patterns, although they have different characteristics. Therefore, these regional monsoons are unified in the context of the global monsoon [1,2], which reflects the dominant mode of coherent annual variations of precipitation and atmospheric circulations in the tropics and subtropics.

关键词： global system land-monsoon super-cycle

Three-dimensional spiral structure of tropical cyclone under four-force balance

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Chinese Physics B 2014年第6期23卷 644-648页

作者：刘式适付遵涛刘式达 Department of Atmospheric and oceanic Sciences and laboratory for climate and ocean–atmosphere studies School of Physics Peking University

The steady axis-symmetrical atmosphere dynamical equations are used for describing spiral structure of tropical cyclones under four-force （pressure gradient force, Coriolis force, centrifugal force, and friction force） balance, and the dynamical systems of three-dimensional （3D） velocity field are introduced. The qualitative analysis of the dynamical system shows that there are down 3D spiral structures in eye of tropical cyclone and tropical cyclone is 3D counterclockwise up spiral structure. These results are consistent with the observed tropical cyclone on the weather map.

关键词： tropical cyclones spiral structure dynamical systems four-force balance

Definition of the South China Sea summer monsoon onset

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Chinese Journal of oceanology and Limnology 2010年第6期28卷 1281-1289页

作者：田莹王启 ocean-atmosphere Interaction and climate laboratory(OAC) Ocean University of China

We analyze statistically different definitions of the South China Sea summer monsoon(SCSSM) onset are to establish a SCSSM onset time series that is more recognizable by a majority of *** the acknowledged index,we determine a key area(105°E-112.5°E,7.5°N-12.5°N) and define the zonal wind component in this key area as a new SCSSM onset index,using daily mean reanalysis data of the National Center for Environmental Prediction/National Center for Atmospheric *** atmospheric circulations before and after the onset of the SCSSM determined using the index defined in this paper are preliminarily *** show that the Somalia cross-equatorial flow is enhanced,the strongest westerly wind in the tropical Indian ocean shifts northward,the cyclone couple in the Bay of Bengal and the Southern Hemisphere weaken and move eastward,convection over the South China Sea increases,and the subtropical high retreats from the South China Sea after the outbreak of the *** analyzing the atmospheric circulation,it is found that in 1984 and 1999,the SCSSM broke out in pentads 29 and 23,respectively,which is consistent with the onset times determined using our index.

关键词： South China Sea summer monsoon (SCSSM) atmospheric circulation index

Robust GEFA Assessment of climate Feedback to SST EOF Modes

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Advances in Atmospheric Sciences 2011年第4期28卷 907-912页

作者：范磊刘征宇刘秦玉 Physical oceanography laboratory Ocean-Atmosphere Interaction and Climate LaboratoryOcean University of China Center for Climatic Research Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin-Madison Center of climate Ocean-Atmosphere StudiesPeking University

Atmospheric response to SST variability was estimated using generalized equilibrium feedback analysis （GEFA） in the SST EOF space with synthesis data from an idealized climate model. Results show that the GEFA atmospheric response to the leading SST EOF modes is much more accurate and robust than the GEFA feedback matrix in physical space. Therefore, GEFA provides a practical method for assessing atmospheric response to large-scale SST anomalies in terms of the leading EOFs.

关键词： generalized equilibrium feedback analysis (GEFA) assessment climate feedback SST EOF

The Predictability of a Squall Line in South China on 23 April 2007

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Advances in Atmospheric Sciences 2013年第2期30卷 485-502页

作者：吴多常孟智勇严大春 laboratory for climate and ocean-atmosphere studies Department of Atmospheric and Oceanic Sciences School of PhysicsPeking University

This study investigated the predictability of a squall line associated with a quasi-stationary front on 23 April 2007 in South China through deterministic and probabilistic forecasts. Our results show that the squallline simulation was very sensitive to model error from horizontal resolution and uncertainties in physical parameterization schemes. At least a 10-km grid size was necessary to decently capture this squall line. The simulated squall line with a grid size of 4.5 km was most sensitive to long-wave radiation parameterization schemes relative to other physical schemes such as microphysics and planetary boundary layer. For a grid size from 20 to 5 km, a cumulus parameterization scheme degraded the squall-line simulation （relative to turning it off）, with a more severe degradation to grid size -10 km than 〉10 km. The sensitivity of the squall-line simulation to initial error was investigated through ensemble forecast. The performance of the ensemble simulation of the squall line was very sensitive to the initial error. Approximately 15% of the ensemble members decently captured the evolution of the squall line, 25% failed, and 60% dislocated the squall line. Using different combinations of physical parameterization schemes for different members can improve the probabilistic forecast. The lead time of this case was only a few hours. Error growth was clearly associated with moist convection development. A linear improvement in the performance of the squall line simulation was observed when the initial error was decreased gradually, with the largest contribution from initial moisture field.

关键词： squall line predictability South China ensemble moisture

The Formation of Wind Curl in the Marine atmosphere Boundary Layer over the East China Sea Kuroshio in Spring

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Journal of ocean University of China 2014年第6期13卷 883-892页

作者： ZHANG Suping KONG Yang Physical oceanography laboratory and Ocean-Atmosphere Interaction and Climate LaboratoryOcean University of China

Various data are used to investigate the characteristics of the surface wind field and rainfall on the East China Sea Kuroshio(ESK) in March and April, 2011. In March, the wind speed maximum shows over the ESK front(ESKF) in the 10 meter wind field, which agrees with the thermal wind effect. A wind curl center is generated on the warm flank of the ESKF. The winds are much weaker in April, so is the wind curl. A rainband exists over the ESKF in both the months. The Weather Research and Forecasting(WRF) model is used for further researches. The winds on the top of the marine atmosphere boundary layer(MABL) indicate that in March, a positive wind curl is generated in the whole MABL over the warm flank of the ESKF. The thermal wind effect forced by the strong SST gradient overlying the background wind leads to strong surface northeasterly winds on the ESKF, and a positive shearing vorticity is created over the warm flank of the ESKF to generate wind curl. In the smoothed sea surface temperature experiment, the presence of the ESKF is responsible for the strong northeast winds in the ESKF, and essential for the distribution of the rainfall centers in March, which confirms the mechanism above. The same simulation is made for April, 2011, and the responses from the MABL become weak. The low background wind speed weakens the effect of the thermal wind, thus no strong Ekman pumping is helpful for precipitation. There is no big difference in rainfall between the control run and the smooth SST run. Decomposition of the wind vector shows that local wind acceleration induced by the thermal wind effect along with the variations in wind direction is responsible for the pronounced wind curl/divergence over the ESKF.

关键词： the East China Sea Kuroshio front Ekman pumping thermal wind effect precipitation

Impact of assimilating Taiwan＇s coastal radar radial velocity on forecasting Typhoon Morakot (2009) in southeastern China using a WRF-based EnKF

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Science China Earth Sciences 2017年第2期60卷 315-327页

作者： YUE Jian MENG ZhiYong laboratory for climate and ocean-atmosphere studies Department of Atmospheric and Oceanic Sciences School of Physics Peking University Beij'ing 100871 China

This study explores for the first time the impact of assimilating radial velocity(Vr)observations from a single or multiple Taiwan's coastal radars on tropical cyclone(TC)forecasting after landfall in the Chinese mainland by using a Weather Research and Forecasting model(WRF)-based ensemble Kalman filter(EnKF)data assimilation *** Morakot(2009),which caused widespread damage in the southeastern coastal regions of the mainland after devastating Taiwan,was chosen as a case *** results showed that assimilating Taiwan's radar Vr data improved environmental field and steering flow and produced a more realistic TC position and structure in the final EnKF cycling ***,the subsequent TC track and rainfall forecasts in southeastern China were *** addition,better observations of the TC inner core by Taiwan's radar was a primary factor in improving TC rainfall forecast in the Chinese mainland.

关键词： Radial velocity EnKF TC track forecast Rainfall forecast Chinese mainland

Impact of the Pacific–Japan Teleconnection Pattern on July Sea Fog over the Northwestern Pacific: Interannual Variations and Global Warming Effect

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Advances in Atmospheric Sciences 2016年第4期33卷 511-521页

作者： Jingchao LONG Suping ZHANG Yang CHEN Jingwu LIU Geng HAN Physical oceanography laboratory Ocean-Atmosphere Interaction and Climate LaboratoryOcean University of China Meteorological bureau of Quanzhou

The northwestern Pacific （NWP） is a fog-prone area, especially the ocean east of the Kuril Islands. The present study analyzes how the Pacific-Japan （PJ） teleconnection pattern influences July sea fog in the fog-prone area using independent datasets. The covariation between the PJ index and sea fog frequency （SFF） index in July indicates a close correlation, with a coefficient of 0.62 exceeding the 99% confidence level. Composite analysis based on the PJ index, a case study, and model analysis based on GFDL-ESM2M, show that in high PJ index years the convection over the east of the Philippines strengthens and then triggers a Rossby wave, which propagates northward to maintain an anticyclonic anomaly in the midlatitudes, indicating a northeastward shift of the NWP subtropical high. The anticyclonic anomaly facilitates the formation of relatively stable atmospheric stratification or even an inversion layer in the lower level of the troposphere, and strengthens the horizontal southerly moisture transportation from the tropical-subtropical oceans to the fog-prone area. On the other hand, a greater meridional SST gradient over the cold flank of the Kuroshio Extension, due to ocean downwelling, is produced by the anticyclonic wind stress anomaly. Both of these two aspects are favorable for the warm and humid air to cool, condense, and form fog droplets, when air masses cross the SST front. The opposite circumstances occur in low PJ index years, which are not conducive to the formation of sea fog. Finally, a multi-model ensemble mean projection reveals a prominent downward trend of the PJ index after the 2030s, implying a possible decline of the SFF in this period.

关键词： Pacific-Japan teleconnection sea fog frequency northwestern Pacific global warming