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Atmospheric and Oceanic Science Letters 2025年第1期18卷 6-11页

作者： Haoyu Zhou Pang-Chi Hsu Lin Chen Yitian Qian Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environmental Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjingChina

During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the subtropical Northwestern Pacific(10°-20°N,130°E-175°W).The former is well-documented and considered to be influenced by the ENSO,while the latter has received comparatively less attention and is likely influenced by the Pacific Meridional Mode(PMM),as suggested by partial correlation analysis *** elucidate the physical processes responsible for the enhanced(weakened)intraseasonal convection over the subtropical northwestern Pacific during warm(cold)PMM years,the authors employed a moisture budget *** findings reveal that during warm PMM years,there is an increase in summer-mean moisture over the subtropical northwestern *** increase interacts with intensified vertical motion perturbations in the region,leading to greater vertical moisture advection in the lower troposphere and consequently resulting in convective *** a process is pivotal in amplifying intraseasonal convection *** observational findings were further verified by model experiments forced by PMM-like sea surface temperature patterns.

关键词： Boreal summer intraseasonal oscillation Interannual variability Pacific Meridional Mode Moisture budget analysis

Application of the improved dung beetle optimizer,muti-head attention and hybrid deep learning algorithms to groundwater depth prediction in the Ningxia area,China

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 18-23页

作者： Jiarui Cai Bo Sun Huijun Wang Yi Zheng Siyu Zhou Huixin Li Yanyan Huang Peishu Zong collaborative innovation center on forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjingChina Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) ZhuhaiChina China Meteorological Administration Key Laboratory of Transportation MeteorologyNanjingChina jiangsu Meteorological Observatory NanjingChina

Due to the lack of accurate data and complex parameterization,the prediction of groundwater depth is a chal-lenge for numerical *** learning can effectively solve this issue and has been proven useful in the prediction of groundwater depth in many *** this study,two new models are applied to the prediction of groundwater depth in the Ningxia area,*** two models combine the improved dung beetle optimizer(DBO)algorithm with two deep learning models:The Multi-head Attention-Convolution Neural Network-Long Short Term Memory networks(MH-CNN-LSTM)and the Multi-head Attention-Convolution Neural Network-Gated Recurrent Unit(MH-CNN-GRU).The models with DBO show better prediction performance,with larger R(correlation coefficient),RPD(residual prediction deviation),and lower RMSE(root-mean-square error).Com-pared with the models with the original DBO,the R and RPD of models with the improved DBO increase by over 1.5%,and the RMSE decreases by over 1.8%,indicating better prediction *** addition,compared with the multiple linear regression model,a traditional statistical model,deep learning models have better prediction performance.

关键词： Groundwater depth Multi-head attention Improved dung beetle optimizer CNN-LSTM CNN-GRU Ningxia

Parameterization of Sheared Entrainment in a Well-developed ***Ⅱ:A Simple Model for Predicting the Growth Rate of the CBL

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Advances in Atmospheric Sciences 2016年第10期33卷 1185-1198页

作者： Peng LIU Jianning SUN Lidu SHEN School of Atmospheric Sciences&Institute for Climate and Global ChangeNanjing UniversityNanjing 210023China jiangsu provincial collaborative innovation center of climate change Nanjing 210023China

Following the parameterization of sheared entrainment obtained in the companion paper, Liu et al. （2016）, the present study aims to further investigate the characteristics of entrainment, and develop a simple model for predicting the growth rate of a well-developed and sheared CBL. The relative stratification, defined as the ratio of the stratification in the free atmosphere to that in the entrainment zone, is found to be a function of entrainment flux ratio （Ae）. This leads to a simple expression of the entrainment rate, in which Ae needs to be parameterized. According to the results in Liu et al. （2016）, Ae can be simply expressed as the ratio of the convective velocity scale in the sheared CBL to that in the shear-free CBL. The parameterization of the convective velocity scale in the sheared CBL is obtained by analytically solving the bulk model with several assumptions and approximations. Results indicate that the entrainment process is influenced by the dynamic effect, the interaction between mean shear and environmental stratification, and one other term that includes the Coriolis effect. These three parameterizations constitute a simple model for predicting the growth rate of a well-developed and sheared CBL. This model is validated by outputs of LESs, and the results show that it performs satisfactorily. Compared with bulk models, this model does not need to solve a set of equations for the CBL. It is more convenient to apply in numerical models.

关键词： sheared convective boundary layer relative stratification parameter entrainment rate entrainment flux ratio,convective velocity scale

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changes in Regional Heavy Rainfall Events in China during 1961–2012

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Advances in Atmospheric Sciences 2015年第5期32卷 704-714页

作者： ZOU Xukai REN Fumin National climate center State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences jiangsu collaborative innovation center for climate change

A new technique for identifying regional climate events, the Objective Identification Technique for Regional Extreme Events（OITREE）, was applied to investigate the characteristics of regional heavy rainfall events in China during the period1961–2012. In total, 373 regional heavy rainfall events（RHREs） were identified during the past 52 years. The East Asian summer monsoon（EASM） had an important influence on the annual variations of China＇s RHRE activities, with a significant relationship between the intensity of the RHREs and the intensity of the Mei-yu. Although the increase in the frequency of those RHREs was not significant, China experienced more severe and extreme regional rainfall events in the 1990 s. The middle and lower reaches of the Yangtze River and the northern part of South China were the regions in the country most susceptible to extreme precipitation events. Some stations showed significant increasing trends in the southern part of the middle and lower reaches of the Yangtze River and the northern part of South China, while parts of North China, regions between Guangxi and Guangdong, and northern Sichuan showed decreasing trends in the accumulated intensity of *** spatial distribution of the linear trends of events＇ accumulated intensity displayed a similar so-called ＂southern flooding and northern drought＂ pattern over eastern China in recent decades.

关键词： China regional heavy rainfall events

Characteristics of Secondary Circulations in the Convective Boundary Layer over Two-Dimensional Heterogeneous Surfaces

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Journal of Meteorological Research 2016年第6期30卷 944-960页

作者： SHEN Lidu SUN Jianning and LIU Peng School of Atmospheric Sciences & Institute for climate and Global change Nanjing University jiangsu provincial collaborative innovation Centre of climate change School of Earth and Space Sciences University of Science and Technology of China

Large-eddy simulations are conducted to investigate the impacts of the scale of chessboard-like heteroge- neous surface heating and the background wind on secondary circulations （SCs） in the convective boundary layer （CBL）. When the wind blows along the diagonal of the chessboard pattern, the cases with different heterogeneity length scales （λ = 1.2, 2.4, and 4.8 km） and weak background wind （U = 2.5 m s-1） suggest that there exists a threshold for the roll-like SCs, which is satisfied when the heterogeneity length scale is 1.6 times the boundary layer height （λ = 1.6zi）. During the CBL development, the SC intensity increases before this threshold is met, whereas it decreases thereafter. The cases with different background wind speeds （U = 2.5, 5.0, and 10.0 m s-1） and relatively large heterogeneity length scale （λ = 4.8 km） show that the SCs are strengthened by larger wind speeds when the heterogeneity length scale is so large that the threshold cannot be met during the CBL development. Another case with wind direction along neither the diagonal nor the side of the chessboard pattern shows that the roll-like SCs can still be triggered, but the roll axes are orientated along the diagonal of the chessboard pattern rather than along the wind direction.

关键词： background wind convective boundary layer heterogeneous surface large-eddy simulation secondary circulation turbulence

Impact of Initial Storm Intensity and Size on the Simulation of Tropical Cyclone Track and Western Pacific Subtropical High Extent

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Journal of Meteorological Research 2017年第5期31卷 946-954页

作者： Yuxing WANG Yuan SUN Qianfeng LIAO Zhong ZHONG Yijia HU Kefeng LIU College of Meteorology and Oceanography National University of Defense Technology jiangsu collaborative innovation center for climate change Nanjing University

Typhoon Megi, the 13th typhoon of the 2010 typhoon season, was selected for case study by utilizing the Weather Research and Forecasting （WRF） model. Twelve sensitivity experiments with various initial tropical cyclone （TC） in- tensities and sizes were conducted to investigate their impacts on the simulation of typhoon track. Interaction between TC and the western Pacific subtropical high （WPSH） was also analyzed to explore the mechanism for the impact on TC track of the initial TC intensity and size. Numerical results indicate that the simulated TC size and TC track are sensitive to initial TC intensity and size. Stronger initial TC intensity and larger initial TC size often lead to larger simulated TC size and make TC turn northward earlier. Further analysis suggests that, with the increase of ini- tial TC intensity and size, more air mass enters into the TC region, which subsequently reduces the extent of WPSH. As a result, the steering flow changes significantly and eventually causes the TC to turn northward earlier. The present study confirms that the initial TC intensity and size have certain influences on the TC track simulation, which demonstrates the importance of accurate initial condition for successful simulation of the TC intensity and TC track. Moreover, it also deepens our understanding of the interaction between TC and WPSH, provides helpful clues for the TC track change study, and discusses the future directions for improvement of TC track forecast.

关键词： tropical cyclone size subtropical high tropical cyclone track WRF model

Vortex Rossby Waves in Asymmetric Basic Flow of Typhoons

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Advances in Atmospheric Sciences 2018年第5期35卷 531-539页

作者： Tianju WANG Zhong ZHONG Ju WANG College of Meteorology and Oceanography National University of Defense Technology jiangsu collaborative innovation center for climate change Nanjing University

Wave ray theory is employed to study features of propagation pathways（rays） of vortex Rossby waves in typhoons with asymmetric basic flow, where the tangential asymmetric basic flow is constructed by superimposing the wavenumber-1 perturbation flow on the symmetric basic flow, and the radial basic flow is derived from the non-divergence equation. Results show that, in a certain distance, the influences of the asymmetry in the basic flow on group velocities and slopes of rays of vortex Rossby waves are mainly concentrated near the radius of maximum wind（RMW）, whereas it decreases outside the RMW. The distributions of radial and tangential group velocities of the vortex Rossby waves in the asymmetric basic flow are closely related to the azimuth location of the maximum speed of the asymmetric basic flow, and the importance of radial and tangential basic flow on the group velocities would change with radius. In addition, the stronger asymmetry in the basic flow always corresponds to faster outward energy propagation of vortex Rossby waves. In short, the group velocities, and thereby the wave energy propagation and vortex Rossby wave ray slope in typhoons, would be changed by the asymmetry of the basic flow.

关键词： asymmetric basic flow vortex Rossby waves group velocity propagation pathways wave ray

Observational study of land-atmosphere turbulent flux exchange over complex underlying surfaces in urban and suburban areas

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Science China Earth Sciences 2021年第7期64卷 1050-1064页

作者： Jie SHA Jun ZOU Jianning SUN School of Atmospheric Sciences Nanjing UniversityNanjing 210023China Joint International Research Laboratory of Atmospheric and Earth System Sciences Nanjing UniversityNanjing 210023China jiangsu provincial collaborative innovation center of climate change Nanjing 210023China

Based on observation data from urban observation stations in Nanjing and Suzhou at two heights in the roughness sublayer above the canopy and observation data at three heights in the SORPES station at the Xianlin Campus of Nanjing University in a suburban area,the of land-atmosphere turbulent flux exchange and the energy balance over complex underlying surfaces were *** results indicated that in the roughness sublayer above the canopy,the nearsurface momentum flux,sensible heat flux,and latent heat flux increase with height,and the observation value of the surface albedo increases with ***,the observation value of the net radiation decreases with height,thus resulting in a change in the urban surface energy budget with *** the SORPES station in the Xianlin Campus of Nanjing University located in a hilly area,the momentum flux,sensible heat flux,and latent heat flux of the ground observation field significantly differed from those of the two heights on the tower,while the two heights on the tower were extremely *** results indicate that the flux observation over the complex underlying surface exhibits adequate local only when it is conducted at a higher altitude above the *** turbulent flux observation results at a lower altitude in urban areas are underestimated,while the turbulent flux observation results near the surface produce a large deviation over the underlying hilly complex.

关键词： Complex underlying surface Land-atmosphere exchange Turbulent flux Observation height Local representativeness

Aerosol as a critical factor causing forecast biases of air temperature in global numerical weather prediction models

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Science Bulletin 2021年第18期66卷 1917-1924,M0004页

作者： Xin Huang Aijun Ding School of Atmospheric Sciences Nanjing University jiangsu provincial collaborative innovation center of climate change Nanjing 210023China

Weather prediction is essential to the daily life of human beings. Current numerical weather prediction models such as the Global Forecast System(GFS) are still subject to substantial forecast biases and rarely consider the impact of atmospheric aerosol, despite the consensus that aerosol is one of the most important sources of uncertainty in the climate system. Here we demonstrate that atmospheric aerosol is one of the important drivers biasing daily temperature prediction. By comparing observations and the GFS prediction, we find that the monthly-averaged bias in the 24-h temperature forecast varies between ± 1.5 ℃ in regions influenced by atmospheric aerosol. The biases depend on the properties of aerosol, the underlying land surface, and aerosol–cloud interactions over oceans. It is also revealed that forecast errors are rapidly magnified over time in regions featuring high aerosol loadings. Our study provides direct ‘‘observational" evidence of aerosol’s impacts on daily weather forecast, and bridges the gaps between the weather forecast and climate science regarding the understanding of the impact of atmospheric aerosol.

关键词： Weather prediction Atmospheric aerosol Temperature forecast errors Aerosol-radiation interactions Aerosol-cloud interactions

Global Financial Crisis Making a V-Shaped Fluctuation in NO_2 Pollution over the Yangtze River Delta

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Journal of Meteorological Research 2017年第2期31卷 438-447页

作者： Yin DU Zhiqing XIE Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Climate Dynamics Research CenterNanjing University of Information Science &Technology jiangsu climate center Jiangsu Meteorological Administration

The Yangtze River Delta（YRD）,China’s main cultural and economic center,has become one of the most seriously polluted areas in the world with respect to nitrogen oxides（NO_x）,owing to its rapid industrialization and urbanization,as well as substantial coal *** the basis of nitrogen dioxide（NO_2）density data from ozone monitoring instrument（OMI）and ground-based observations,the effects of industrial fluctuations due to the financial crisis on local NO_2 pollution were quantitatively *** results were as follows.（1）A distinct V-shaped fluctuation of major industrial products,thermal generating capacity,electricity consumption,and tropospheric NO_2 densities was associated with the global financial crisis from May 2007 to December 2009,with the largest anomalies 1.5 times more than standard deviations at the height of the crisis period from November 2008 to February 2009.（2）Among all industrial sectors,thermal power plants were mainly responsible for fluctuations in local NO_2 pollution during the crisis *** generating capacity had its greatest decrease of 12.10%at the height of the crisis compared with that during November 2007–February 2008,leading to local tropospheric NO_2 density decreasing by 16.97%.As the crisis appeased,thermal generating capacity increased by 29.63%from November 2009 to February 2010,and tropospheric NO_2 densities correspondingly increased by 30.07%.（3）Among all industrial sectors in the YRD,the thermal power sector has the greatest coal consumption of about 65.96%.A decline in thermal power of about 10% can induce a decrease of about 30%in NOx emissions and NO_2 densities,meaning that a relative small fluctuation in industrial production can lead to a large decrease in tropospheric NO_2 densities over industrially developed areas like the YRD *** electricity is mainly obtained from local coal-burning thermal plants without NO_x-processing equipment,installing NO_x-removal devices for all thermal power pl

关键词： financial crisis abrupt change NO_x pollution