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The Linkage between the Pacific-North American Teleconnection Pattern and the North Atlantic Oscillation

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Advances in atmospheric sciences 2009年第2期26卷 229-239页

作者：宋洁李崇银周文潘静 State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics (IAP) Chinese Academy of Sciences Graduate University of Chinese Academy of sciences cityu-iap laboratory for atmospheric sciences Department of Physics and Materials Science City University of Hong Kong

In this study, using the ECMWF reanalysis data, the possible linkage between the Pacific-North American teleconnection pattern （PNA） and the North Atlantic Oscillation （NAO） during boreal winter （December- February） is investigated. The PNA and the NAO pattern are obtained by performing Rotated Empirical Orthogonal Function （REOF） analysis on an anomalous daily mean 300-hPa geopotential height field. The composite daily NAO indices show that the NAO indices are prone to be negative （positive） when the contemporary PNA indices are extremely positive （negative）. The correlation coefficients between the daily PNA and NAO indices also confirm that, indeed, there is a significant anti-correlation between the PNA and NAO indices. The correlation peaks at a lag of 0 days （meaning contemporary correlation）, and its value is 0.202. Analyses of a newly defined Rossby wave breaking index and diagnostics of the stream function tendency equation indicate that the anti-correlation between PNA and NAO may be caused by the anomalous Rossby wave breaking events associated with the PNA pattern.

关键词： Pacific-North American teleconnection pattern (PNA) North Atlantic Oscillation (NAO) wave breaking

Prediction of the Asian-Australian Monsoon Interannual Variations with the Grid-Point atmospheric Model of iap LASG(GAMIL)

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Advances in atmospheric sciences 2008年第3期25卷 387-394页

作者：吴志伟李建平 State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric Physics(IAP) State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric Physics(IAP)Chinese Academy of Sciences100029

Seasonal prediction of Asian-Australian monsoon （A-AM） precipitation is one of the most important and challenging tasks in climate prediction. In this paper, we evaluate the performance of Grid atmospheric Model of iap LASG （GAMIL） on retrospective prediction of the A-AM interannual variation （IAV）, and determine to what extent GAMIL can capture the two major observed modes of A-AM rainfall IAV for the period 1979-2003. The first mode is associated with the turnabout of warming （cooling） in the Nifio 3.4 region, whereas the second mode leads the warming/cooling by about one year, signaling precursory conditions for ENSO. We show that the GAMIL one-month lead prediction of the seasonal precipitation anomalies is primarily able to capture major features of the two observed leading modes of the IAV, with the first mode better predicted than the second. It also depicts the relationship between the first mode and ENSO rather well. On the other hand, the GAMIL has deficiencies in capturing the relationship between the second mode and ENSO. We conclude：（1） successful reproduction of the E1 Nifio-excited monsoon-ocean interaction and E1 Nifio forcing may be critical for the seasonal prediction of the A-AM rainfall IAV with the GAMIL; （2） more efforts are needed to improve the simulation not only in the Nifio 3.4 region but also in the joining area of Asia and the Indian-Pacific Ocean; （3） the selection of a one-tier system may improve the ultimate prediction of the A-AM rainfall IAV. These results offer some references for improvement of the GAMIL and associated seasonal prediction skill.

关键词： Asian-Australian monsoon interannual variation ENSO atmospheric general circulation model GAMIL

Influence of South China Sea SST and the ENSO on Winter Rainfall over South China

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Advances in atmospheric sciences 2010年第4期27卷 832-844页

作者：周连童 Chi-Yung TAM 周文 Johnny C. L. CHAN Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of Sciences cityu-iap laboratory for atmospheric sciences City University of Hong Kong Guy Carpenter Asia-Pacific Climate Impact Centre School of Energy and EnvironmentCity University of Hong Kong

The present study investigates the influence of South China Sea （SCS） SST and ENSO on winter （January-February-March; JFM） rainfall over South China and its dynamic processes by using station observations for the period 1951-2003, Met Office Hadley Center SST data for the period 1900-2008, and ERA-40 reanalysis data for the period 1958-2002. It is found that JFM rainfall over South China has a sig- nificant correlation with Nio-3 and SCS SST. Analyses show that in El Nio or positive SCS SST anomaly years, southwesterly anomalies at 700 hPa dominate over the South China Sea, which in turn transports more moisture into South China and favors increased rainfall. A partial regression analysis indicates that the independent ENSO influence on winter rainfall occurs mainly over South China, whereas SCS SST has a larger independent influence on winter rainfall in northern part of South China. The temperature over South China shows an obvious decrease at 300 hPa and an increase near the surface, with the former induced by Nio-3 and the latter SCS SST anomalies. This enhances the convective instability and weakens the potential vorticity （PV）, which explains the strengthening of ascending motion and the increase of JFM rainfall over South China.

关键词： ENSO South China Sea SST rainfall convective instability potential vorticity

EXPERIMENTS OF SEA ICE SIMULATION

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Journal of Hydrodynamics 2005年第6期17卷 686-692页

作者： LIU Xi-ying State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics （LASG） Institute of Atmospheric Physics （IAP） Chinese Academy of Sciences Beijing 100029 China

As a substitute for the original displaced pole grids, a simple rotated spherical coordinate system was intro duced into the Community Sea Ice Model version 4（CSIM4）, which is a component of the Community Climate System Model（CCSM） of the American National Center of atmospheric Researeh（NCAR）, to deal with the ＂pole problems＂. In the new coordinates, both the geographical North Pole and South Pole lie in the model equator and grid sizes near the polar region are more uniform. With reanalysis dataset of American National Centers for Environment Prediction （NCEP） and Levitus dataset without considering sub-mixed layer heat flux, the model was integrated for 100 years with thermodynamics *** involved only in the former 49 years and both dynamic and thermodynamic processes involved in the left time. Inner consistency of model results was checked with no contradiction found. The results of last 10 years＇ model output were analyzed and it is shown that the simulated sea ice seasonal variation is rational whereas sea ice extent in the Barcnts Sea in winter is larger than that of observation, Numerical experiment on influence of sub-mixed layer heat flux was also carried out and it is shown that the sub-mixed layer heat flux can modulate seasonal variation of sea ice greatly. As a model component, the sea ice model with rotated spherical coordinates was coupled with other models （the oceanic general cir culation model is the LASG/iap Climate System Ocean Model （LICOM） with reduced grid, other models are components of NCAR CCSM2） forming a climate system model and its preliminary results were also given briefly.

关键词： sea ice numerical simulation climate system model

Relationships between the North Pacific Oscillation and the typhoon/hurricane frequencies

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Science China Earth sciences 2007年第9期50卷 1409-1416页

作者： WANG HuiJun SUN JianQi FAN Ke Institute of atmospheric Physics (iap) Chinese Academy of Sciences Beijing 100029 China Institute of Atmospheric Physics (IAP) Chinese Academy of Sciences Beijing 100029 China Institute of Atmospheric Physics (IAP) Chinese Academy of Sciences Beijing 100029 China

Relationships between the North Pacific Oscillation (NPO) and the typhoon as well as hurricane fre-quencies are documented. The correlation between NPO index in June-July-August-September and the annual typhoon number in the western North Pacific is 0.37 for the period of 1949―1998. The NPO is correlated with the annual hurricane number in the tropical Atlantic at -0.28 for the same period. The variability of NPO is found to be concurrent with the changes of the magnitude of vertical zonal wind shear, sea-level pressure patterns, as well as the sea surface temperature, which are physically asso- ciated with the typhoons and hurricanes genesis. The NPO associated atmospheric circulation vari- ability is analyzed to explain how NPO is linked with variability of the tropical atmospheric circulation in the western Pacific and the tropical Atlantic, via the atmospheric teleconnection.

关键词： Western North Pacific Typhoon, tropical Atlantic hurricane, North Pacific oscillation, typhoon/hurricane frequency

Coupled Model Simulations of Climate Changes in the 20th Century and Beyond

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Advances in atmospheric sciences 2008年第4期25卷 641-654页

作者：俞永强智海王斌万慧李超刘海龙李薇郑伟鹏周天军 State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric Physics(IAP)Chinese Academy of Sciences

Several scenario experiments of the IPCC 4th Assessment Report （AR4） are performed by version g1.0 of a Flexible coupled Ocean-Atmosphere-Land System Model （FGOALS） developed at the Institute of atmospheric Physics, Chinese Academy of sciences （iap/CAS）, including the ＂Climate of the 20th century experiment＂, ＂CO2 1% increase per year to doubling experiment＂ and two separate IPCC greenhouse gases emission scenarios AIB and B1 experiments. To distinguish between the different impacts of natural variations and human activities on the climate change, three-member ensemble runs are performed for each scenario experiment. The coupled model simulations show：（1） from 1900 to 2000, the global mean temper- ature increases about 0.5℃ and the major increase occurs during the later half of the 20th century, which is in consistent with the observations that highlights the coupled model＇s ability to reproduce the climate changes since the industrial revolution; （2） the global mean surface air temperature increases about 1.6℃ in the CO2 doubling experiment and 1.5℃ and 2.4℃ in the A1B and B1 scenarios, respectively. The global warming is indicated by not only the changes of the surface temperature and precipitation but also the temperature increase in the deep ocean. The thermal expansion of the sea water would induce the rise of the global mean sea level. Both the control run and the 20th century climate change run are carried out again with version g1.1 of FGOALS, in which the cold biases in the high latitudes were removed. They are then compared with those from version g1.0 of FGOALS in order to distinguish the effect of the model biases on the simulation of global warming.

关键词： greenhouse effect coupled GCM human activity

Apolipoprotein E elicits targetdirected miRNA degradation to maintain neuronal integrity

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Neural Regeneration Research 2025年第9期20卷 2577-2578页

作者： Jiazi Tan Chin-Tong Ong Temasek Life sciences laboratory National University of SingaporeSingapore Department of Biological sciences National University of SingaporeSingapore

Apolipoprotein E has diverse functions in neurons:Apolipoprotein E(ApoE)is a glycoprotein that primarily regulates lipid metabolism and transport in the central nervous *** are three predominant human ApoE protein isoforms with cysteine and arginine substitutions at amino acid positions 112 and 158 that impact their lipidation and related functions(Flowers and Rebeck,2020).ApoE2 is characterized by Cys112 and Cys158,ApoE3 by Cys112 and Arg158,whereas ApoE4 contains Arg112 and Arg158.

关键词： metabolism glycoprotein maintain

The Persistence and Zonal Scale of atmospheric Dipolar Modes

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Advances in atmospheric sciences 2024年第3期41卷 478-492页

作者： Jie SONG State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric Physics(IAP)Chinese Academy of SciencesBeijing 100029China

This study investigates the relationship between the persistence and the zonal scale of atmospheric dipolar modes(DMs). Results from the daily data of ERA5 and the long-term output of an idealized atmospheric model show that the atmospheric DMs with a broader(narrower) zonal scale dipolar structure possess a longer(shorter) persistence. A detailed vorticity budget analysis indicates that the persistence of a hemispheric-scale DM(1/1 DM) and a regional or sectoral DM(1/8 DM) in the model both largely rely on the persistence of the nonlinear eddy forcing. Linear terms can indirectly reduce the persistence of the anomalous nonlinear eddy forcing in a 1/8 DM by modifying the baroclinicity via the arousal of anomalous vertical motions. Therefore, the atmospheric DMs with a broader(narrower) zonal scale possess a longer(shorter) persistence because the effects of the linear terms are less(more) pronounced when the atmospheric DMs have better(worse) zonal symmetry. Further analyses show that the positive eddy feedback effect is weak or even absent in a 1/8DM and the high-frequency eddy forcing acts more like a concomitant phenomenon rather than a leading driving factor for a 1/8 DM. Thus, the hemispheric-scale DM and the regional or sectoral DMs are different, not only in their persistence but also in their dynamics.

关键词： NAM NAO eddy feedback persistence linear term

Sensitivity of the Upper Ocean Temperature and Circulation in the Equatorial Pacific to Solar Radiation Penetration Due to Phytoplankton

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Advances in atmospheric sciences 2007年第5期24卷 765-780页

作者：林鹏飞刘海龙张学洪 State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics(LASG) Institute of atmospheric Physics(iap) Chinese Academy of Sciences(CAS)Beijing 100029 Graduate University of the Chinese Academy of SciencesBeijing 100039 State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics(LASG) Institute of atmospheric Physics(iap) Chinese Academy of Sciences(CAS)Beijing 100029

Solar radiation penetration in the upper ocean is strongly modulated by phytoplankton, which impacts the upper ocean temperature structure, especially in the regions abundant with phytoplankton. In the paper, a new solar radiation penetration scheme, based on the concentration of chlorophyll-a, was introduced into the LASG/iap （State Key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics/Institute of atmospheric Physics） Climate system Ocean Model （LICOM）. By comparing the simulations using this new scheme with those using the old scheme that included the constant e-folding attenuation depths in LICOM, it was found that the sea surface temperature （SST） and circulation in the central and eastern equatorial Pacific were both sensitive to the amount of phytoplankton present. Distinct from other regions, the increase of chlorophyll-a concentration would lead to SST decrease in the central and eastern equatorial Pacific. The higher chlorophyll-a concentration at the equator in comparison to the off-equator regions can enlarge the subsurface temperature gradient, which in turn strengthens the upper current near the equator and induces an enhancing upwelling. The enhancing upwelling can then lead to a decrease in the SST in the central and eastern equatorial Pacific. The results of these two sensitive experiments testify to the fact that the meridional gradient in the chlorophyll-a concentration can result in an enhancement in the upper current and a decrease in the SST, along with the observation that a high chlorophyll-a concentration at the equator is one of the predominant reasons leading to a decrease in the SST. This study points out that these results can be qualitatively different simply because of the choice of the solar radiation penetration schemes for comparison. This can help explain previously reported contradictory conclusions.

关键词： SST solar radiation penetration equatorial Pacific upwelling Chlorophyll-a