Soluble MICB in Plasma and Urine Explains Population Expansions of NKG2D⁺CD4 T Cells Inpatients with Juvenile-Onset Systemic Lupus Erythematosus

Abnormal NKG2D ligand expression has been implicated in the initiation and maintenance of various auto-inflammatory disorders including systemic lupus erythematosus (SLE). This study’s goal was to identify the cellular contexts providing NKG2D ligands for stimulation of the immunosuppressive NKG2D+CD4 T cell subset that has been implicated in modulating juvenile-onset SLE disease activity. Although previous observations with NKG2D+CD4 T cells in healthy individuals pointed towards peripheral B cell and myeloid cell compartments as possible sites of enhanced NKG2DL presence, we found no evidence for a disease-associated increase of NKG2DL-positivity among juvenile-onset SLE B cells and monocytes. However, juvenile-onset SLE patient plasma and matched urine samples were positive by ELISA for the soluble form of the NKG2D ligands MICA and MICB, suggesting that kidney and/or peripheral blood may constitute the NKG2DL positive microenvironments driving NKG2D+CD4 T cell population expansions in this disease.

DNA immunoadsorption for childhood-onset systemic lupus erythematosus

We present a retrospective review of DNA immunoadsorption (DNA-IA) therapy on clinical symptoms as well as indicators in pediatric cases with systemic lupus erythematosus (SLE), and follow up the short-term curative effects. 16 SLE cases were treated by DNA-IA for 3 times every other day. We observed the changes on clinical manifestations and immunological indicators, in order to compare the alteration of these indicators including clinical manifestations, Systemic Lupus Erythematosus Disease Active Index (SLEDAI) scores, 24 hurinary protein excretion, autoantibodies, serum IgG and complement C3. 13 cases were followed up regularly, within 3 months after DNA-IA therapy, 12 cases of clinical manifestations improved (92.3%). SLEDAI scores in 10 cases decreased from (16.20 ± 12.54) to less than 5 (76.9%), 8 cases of ANA, anti-DNA antibodies were negative (61.5%), 13 cases with IgG level in serum recovered to normal (10.39 ± 4.38) g/L, C3 level rose to normal (1.06 ± 0.23) g/L. 3 to 6 months after IA, clinical manifestations and laboratory examinations in all cases got maximum improved. 9 months after IA, SLEDAI score in 2 cases (15.4%) rose to more than 5, anti-DNA antibody in 2 cases (15.4%) became positive, and 1case (7.7%) with serum C3 decreased again. 2 cases died from multiple organs dysfunction within 3 to 6 months after IA. No serious complications were found during DNA-IA. We recommend that DNA immunoadsorption is a safe and effective therapy for active childhood-onset SLE, which could improve clinical symptoms, eliminate ANA and anti-DNA antibodies. Combining with corticosteroids and immunosuppressive drugs, DNA-IA could significantly reduce the activity of disease and protect vital organs function in the short term.

Chinese Systemic Lupus Erythematosus Treatment and Research Group Registry IX： Clinical Features and Survival of Childhood-Onset Systemic Lupus Erythematosus in China

Background： Approximately 15-20% cases of systemic lupus erythematosus （SLE） are diagnosed in children. There have been a Few studies reporting the epidemiological data of pediatric-onset SLE （cSLE） in China, neither comparing the differences between cSLE and adult-onset SLE （aSLE）. The aim of this study was to describe the impact of age of onset on clinical features and survival in cSLE patients in China based on the Chinese SLE Treatment and Research group （CSTAR） database. Methods： We made a prospective study of 225 cSLE patients （aged 〈16 years） and 1759 patients aged 16-50 years based on CSTAR registry. We analyzed initial symptoms, clinical presentations, SLE disease activity, damages, and outcomes ofcSLE, as well as compared with aSLE patients. Results： The mean age ofcSLE patients was 12.16 ± 2.92 years, with 187 （83.1%） females. Fever （P 〈 0.001） as well as mucocutaneous （P 〈 0.001 ） and renal （P = 0.006） disorders were found to be significantly more frequent in cSLE patients as initial symptoms, while muscle and joint lesions were significantly less common compared to aSLE subjects （P 〈 0.001 ）. The eSLE patients were found to present more fi＇equently with malar rash （P = 0.001; odds ratio {OR], 0.624; 95% confidence interval [CI ], 0.470 0.829） but less tYequently with arthritis （P 〈 0.001 ; OR, 2.013; 95% CI, 1.512-2.679） and serositis （P = 0.030; OR, 1.629; 95% CI, 1.053 2.520）. There was no significant difl＇erence in SLE disease activity index scores between cSLE and aSLE groups （P = 0.478）. Cox regression indicated that childhood onset was the risk factor for organ damage in lupus patients （hazard ratio 0.335 [0.170 0.658], P = 0.001）. The survival curves between the cSLE and aSLE groups had no significant difference as determined by the log-rank test （0.557, P = 0.455）. Conclusions： cSLE in China has different clinical features and more inflammation than aSLE patients. Damage may be less in children and there is no difl＇erence in 5- year survival between cSLE and aSLE groups.

Characterization of microbiota in systemic-onset juvenile idiopathic arthritis with different disease severities

BACKGROUND Systemic-onset juvenile idiopathic arthritis (SoJIA) is one of most serious subtypes of juvenile idiopathic arthritis. Although the pathogenesis of SoJIA remains unclear, several studies have suggested a correlation between gut dysbiosis and JIA. Further understanding of the intestinal microbiome may help to establish alternative ways to treat, or even prevent, the disease. AIM To explore alterations in fecal microbiota profiles in SoJIA patients and to evaluate the correlations between microbiota and clinical parameters. METHODS We conducted an observational single-center study at the Pediatric Department of Peking Union Medical College Hospital. Children who were diagnosed with SoJIA at our institution and followed for a minimum period of six months after diagnosis were recruited for the study. Healthy children were recruited as a control group (HS group) during the same period. Clinical data and stool samples were collected from SoJIA patients when they visited the hospital. RESULTS The SoJIA group included 17 active and 15 inactive consecutively recruited children;the control group consisted of 32 children. Firmicutes and Bacteroidetes were the two most abundant phyla among the total sample of SoJIA children and controls. There was a significant difference among the three groups in observed species, which was the highest in the Active-SoJIA group, followed by the Inactive-SoJIA group and then HS group (Active-SoJIA vs HS: P = 0.000;and Inactive-SoJIA vs HS: P = 0.005). We observed a lower Firmicutes/Bacteroidetes ratio in SoJIA patients (3.28 ± 4.47 in Active-SoJIA, 5.36 ± 8.39 in Inactive-SoJIA,and 5.67 ± 3.92 in HS). We also observed decreased abundances of Ruminococcaceae (14.9% in Active-SoJIA, 17.3% in Inactive-SoJIA, and 22.8% in HS;Active-SoJIA vs HS: P = 0.005) and Faecalibacterium (5.1% in Active-SoJIA, 9.9% in Inactive-SoJIA, and 13.0% in HS;Active-SoJIA vs HS: P = 0.000) in SoJIA compared with HS. By contrast, the abundance of Bacteroidaceae was the highest in the Active-SoJIA group, followed by the Inactive-SoJIA and HS groups (16.5% in Active-SoJIA, 12.8% in Inactive-SoJIA, and 9.7% in HS;Active-SoJIA vs HS: P = 0.03). The Spearman correlation analysis revealed a negative correlation between Proteobacteria or Enterobacteriaceae and juvenile arthritis disease activity score on 27 joints (JADAS-27). CONCLUSION The composition of the intestinal microbiota is different in SoJIA patients compared with healthy children. The dysbiosis presents partial restoration in inactive status patients.

Sub-seasonal Prediction of the South China Sea Summer Monsoon Onset in the NCEP Climate Forecast System Version 2

This study depicts the sub-seasonal prediction of the South China Sea summer monsoon onset(SCSSMO)and investigates the associated oceanic and atmospheric processes,utilizing the hindcasts of the National Centers for Environmental Prediction(NCEP)Climate Forecast System version 2(CFSv2).Typically,the SCSSMO is accompanied by an eastward retreat of the western North Pacific subtropical high(WNPSH),development of the cross-equatorial flow,and an increase in the east-west sea surface temperature(SST)gradient.These features are favorable for the onset of westerlies and strengthening of convection and precipitation over the South China Sea(SCS).A more vigorous SCSSMO process shows a higher predictability,and vice versa.The NCEP CFSv2 can successfully predict the onset date and evolution of the monsoon about 4 pentads(20 days)in advance(within 1–2 pentads)for more forceful(less vigorous)SCSSMO processes.On the other hand,the climatological SCSSMO that occurs around the 27th pentad can be accurately predicted in one pentad,and the predicted SCSSMO occurs 1–2 pentads earlier than the observed with a weaker intensity at longer leadtimes.Warm SST biases appear over the western equatorial Pacific preceding the SCSSMO.These biases induce a weaker-thanobserved WNPSH as a Gill-type response,leading to weakened low-level easterlies over the SCS and hence an earlier and less vigorous SCSSMO.In addition,after the SCSSMO,remarkable warm biases over the eastern Indian Ocean and the SCS and cold biases over the WNP induce weaker-than-observed westerlies over the SCS,thus also contributing to the less vigorous SCSSMO.

A Single-Center Experience of Systemic Onset Juvenile Idiopathic Arthritis at a Tertiary Hospital in Jeddah, Saudi Arabia

Background and Objective: Systemic-onset juvenile idiopathic arthritis (JIA) is a major and prevalent subset of arthritis among children and it has a broad spectrum of clinical presentation, course and prognosis. This study described the clinical presentation of systemic-onset JIA in a Saudi-based cohort. Methods: A retrospective chart review was performed of the medical records of children with systemic-onset JIA who were followed up at King Abdul Aziz University Hospital, Jeddah, between January 1997 and December 2013. Patients’ files were reviewed for demographic, clinical, and paraclinical data, which were analyzed using the statistical Package for the Social Sciences. Results: We included 20 patients of both genders (8 boys and 12 girls). The mean age of disease onset was 7 (4.5) years. The most common presenting symptoms were fever (100%), arthritis (100%), and rash (55%). Hepatomegaly (5%), abdominal (5%) and pulmonary manifestations (3%) were less frequent manifestations. Most patients had high white blood cell counts (50%), elevated erythrocyte sedimentation rates (80%) and C-reactive protein levels (90%). The interval between onset of symptoms and diagnosis was 9.4 (12.5) weeks. Patients were treated with non-steroidal anti-inflammatory drugs, methotrexate, steroids, anti-tumor necrosis agents, and disease-modifying anti-rheumatic drugs. Bone marrow biopsy was conducted to exclude malignancy in 20% of the patients. Conclusion: Saudi children with systemic-onset JIA present with prolonged fever and arthritis (mainly oligoarticular rather than polyarticular). Physicians should be aware of the presentation of systemic-onset JIA in our setting in order to make prompt diagnosis and treatment decisions as early as possible. Carful follow-up of febrile patients is paramount to reaching the diagnosis early and initiating treatment.

Differences in Precipitation and Related Wind Dynamics and Moisture and Heat Features in Separate Areas of the South China Sea before and after Summer Monsoon Onset

Using surface and balloon-sounding measurements, satellite retrievals, and ERA5 reanalysis during 2011–20, this study compares the precipitation and related wind dynamics, moisture and heat features in different areas of the South China Sea(SCS) before and after SCS summer monsoon onset(SCSSMO). The rainy sea around Dongsha(hereafter simply referred to as Dongsha) near the north coast, and the rainless sea around Xisha(hereafter simply referred to as Xisha) in the western SCS, are selected as two typical research subregions. It is found that Dongsha, rather than Xisha, has an earlier and greater increase in precipitation after SCSSMO under the combined effect of strong low-level southwesterly winds, coastal terrain blocking and lifting, and northern cold air. When the 950-h Pa southwesterly winds enhance and advance northward, accompanied by strengthened moisture flux, there is a strong convergence of wind and moisture in Dongsha due to a sudden deceleration and rear-end collision of wind by coastal terrain blocking. Moist and warm advection over Dongsha enhances early and deepens up to 200 h Pa in association with the strengthened upward motion after SCSSMO, thereby providing ample moisture and heat to form strong precipitation. However, when the 950-h Pa southwesterly winds weaken and retreat southward, Xisha is located in a wind-break area where strong convergence and upward motion centers move in. The vertical moistening and heating by advection in Xisha enhance later and appear far weaker compared to that in Dongsha, consistent with later and weaker precipitation.

Clinical characteristics of patients with early-and late-onset optic neuromyelitis optica spectrum disease

Objective:To analyze the different clinical features of patients with early-onset(EO-NMOSDs)and late-onset neuromyelitis optica spectrum diseases(LO-NMOSDs).Methods:A total of 51patients with neuromyelitis optica spectrum disease who were diagnosed in our hospital for the first time from January 2015 to December 2022 were included in the First Affiliated Hospital of Hainan Medical College and divided into 22 cases in the EO-NMOSDs group and 29 cases in the LO-NMOSDs group according to whether the age of onset was 50 years old.The basic data,Extended Disability Status Scale(EDSS)score,blood and cerebrospinal fluid test indicators of the two groups were statistically analyzed.Results:There were no significant differences in demographic characteristics,clinical features and serum AQP-4 antibody positivity rate between the two groups(all P>0.05),and there were significant differences in triglycerides(TG),low-density lipoprotein(LDL),apolipoprotein A(APOA),apolipoprotein B(APOB)and lipoprotein a(P=0.010,P=0.048,P=0.014,P=0.061,P=0.001,respectively),and cerebrospinal fluid LDH,There were significant differences between microprotein quantification and EDSS score(P=0.018,P=0.034,P=0.025,respectively),and the level of microprotein quantification in cerebrospinal fluid of LO-NMOSDs had a certain correlation with the degree of disability(r=0.52,P<0.03).Conclusion:LO-NMOSDs and EO-NMOSDs group patients have similar demographic characteristics,serum AQP-4 antibody positive rate and clinical features,but compared with EO-NMOSDs,patients in LO-NMOSDs group are prone to abnormal lipid metabolism,higher trace proteins in cerebrospinal fluid and more likely to be disabled,and among LO-NMOSDs,the higher the trace protein in the cerebrospinal fluid,the more severe the disability status of patients.

A Comparison between Late Preterm and Term Infants with Respiratory Distress Syndrome, Early-Onset Sepsis, and Neonatal Jaundice in Ecuadorian Newborns

Background: To examine the differences in prevalence of respiratory distress syndrome, early-onset sepsis and jaundice, between late preterm infants versus term infants in Ecuadorian newborns. Methods: Study design: Epidemiological, observational, and cross-sectional, with two cohorts of patients. Settings: IESS Quito Sur Hospital at Quito, Ecuador, from February to April of 2020. Participants: This study included 204 newborns, 102 preterm infants, 102 term infants. Results: There are significant differences between late preterm infants and term infants, with a p-value of 0.000 in the prevalence of early sepsis, 70.59% vs. 35.29%. In respiratory distress syndrome between late and term premature infants, significant differences were observed with a p-value of 0.000, the proportion being 55.58% vs. 24.51% respectively. The prevalence of jaundice is higher in term infants with a p value of 0.002, 72.55%, versus 51.96% in late preterm infants, and the mean value of bilirubins in mg/dL was higher in term infants 14.32 versus 12.33 in late preterm infants;this difference is statistically significant with a p value of 0.004. Admission to the NICU is more frequent in late preterm infants with a p-value of 0.000, being 42.16% for late preterm infants vs. 7.84% in term infants;the mean of the hospital days with p-value 0.005, was higher in late preterm infants 4.97 days vs. 3.55 days for term newborns. Conclusion: Due to the conditions of their immaturity, late preterm infants are 2.86 times more likely to present early sepsis than full-term newborns. It is shown that late preterm infants are 2.69 times more likely to have respiratory distress syndrome compared to term infants, therefore, late preterm infants have a longer hospital stay of 4.97 days versus 3.55 days in term infants. Jaundice and mean bilirubin levels are higher in term infants due to blood group incompatibility and insufficient breastfeeding.

Prognostic value of C-reactive protein levels within 6 hours after the onset of acute anterior myocardial infarction with primary PCI

Background Increased levels of inflammatory markers have been documented in various settings of coronary artery disease. The vulnerability of coronary lesions in acute myocardial infarction(AMI) at the time of onset may be related to serum levels of C reactive protein(CRP) on admission, before CRP levels are affected by myocardial damage.Objective This study assessed the predictive value of CRP levels within six hours after the onset of acute anterior myocardial infarction with primary percutaneous coronary intervention(PCI).Methods The plasma CRP of 76 patients with first acute anterior myocardial infarction was measured within 6 hours after onset. They were divided into 2 groups: group 1( n =20) with elevated CRP( ≥0.3mg/dl ) on admission within 6 hours after onset and group 2( n =56) with normal CRP( <0.3mg/dl ) within 6 hours after onset. All patients were treated by primary PCI. The primary combined end points, including death due to cardiac causes, re MI related to the infarction artery(RIA) and repeat intervention of the RIA, and the restenosis rate were assessed in relation to CRP levels within 6 hours after onset. Left ventricular end diastolic volume index(EDVI),end systolic volume index(ESVI),and ejection fraction(EF) on admission and 6 month after the onset were assessed by left ventriculography. Changes in EDVI(ΔEDVI),ESVI(ΔESVI), and EF(ΔEF) were obtained by subtracting respective on admission values from corresponding 6 month follow up values. Results There were no significant differences in baseline characteristics between the two groups. The primary combined end points were significantly more frequent in group 1(20%) than those in group 2( 1.79% , P <0.01 ).In addition, restenosis rates were significantly higher in group 1 than in group 2(41.18% vs 16.07%, P<0.05). Group 1 showed greater increases in left ventricular volume and less improvement in EF compared with group 2(ΔEDVI 6.31 ±2.17 vs 3.29 ±9.46ml/m 2 , ΔESVI 5.92 ±2.31 vs 3.86 ±1.08ml/m 2 , ΔEF 1.92 ±0.47 vs 4.79 ±1.73% , P <0.05 , respectively).Conclusions CRP levels within 6 hours after the onset of AMI might predict adverse outcome after primary PCI and progressive ventricular remodeling within 6 month of AMI.

Onset功能对腔内心电图诊断成功率的影响分析

目的:探讨与分析Onset功能对腔内心电图诊断成功率的影响。方法:2016年6月至2018年6月本院收治的起搏器植入患者77例作为研究对象,在植入后第12个月(±14d),采集所有患者的腔内心电图并分为两份,一份隐去Onset的信息(A图),另一份保持原样(B图),由腔内心电图判别小组进行诊断效果判定。结果:77例患者中共记录了495个EGM,起搏器诊断室性心动过速281个,房性心动过速反应200个,非持续性VT 14个。A图中有370个(74.75%)判别为正确的心律失常事件;根据B图判定,起搏器腔内心电图诊断正确率达79.39%,假阳性率20.61%。结论:Onset功能能提高起搏器植入术患者腔内心电图对于心律失常的诊断成功率,能反映患者的心功能状况,有很好的临床应用价值。

On the Onset of the South China Sea Summer Monsoon in 1998

Through analyzing the NCEP/NCAR reanalysis data, the satellite observational data and the ATLAS-2 mooring buoy observational data, it is shown that May 21 is the onset date of the South China Sea summer monsoon in 1998. There were abrupt variations in the general circulation pattern at the lower troposphere and the upper troposphere, in upper jet stream location and in the convection and rainfall over the South China Sea region corresponding to the outbreak of the South China Sea summer monsoon. It is also indicated that there was rainfall in the southern China coastal region before onset of summer monsoon, but it resulted from the (cold) front activity and cannot be regarded as the sign of summer monsoon outbreak in the South China Sea. Key words Onset - South China Sea summer monsoon - General circulation pattern, Jet stream - Convection This work was supported by the State Key Project for Research—“ The South China Sea Monsoon Experiment”, CAS (KZ951-B1-408) and CNSF (49823002).

Characteristics of the Onset of the Asian Summer Monsoon and the Importance of Asian-Australian "Land Bridge"

Based on summarizing previous achievements and characteristics of Asian summer monsoon and the role using data as long and new as possible, the onset of Asian-Australian ＂land bridge＂ in the onset of summer monsoon are further discussed. In particular, the earliest onset area of Asian summer monsoon is comparatively analyzed, and the sudden and progressive characteristics of the onset of summer monsoon in different regions are discussed, Furthermore, the relationships among such critical events during the onset of Asian summer monsoon as the splitting of subtropical high belt over the Bay of Bengal （BOB）, the initiation of convection over Indo-China Peninsula, the westward advance, reestablishment of South Asian High, and the rapid northward progression of convection originated from Sumatra in early summer are studied. The important impact of the proper collocation of she latent heating over Indo-China Peninsula and the sensible heating over Indian Peninsula on the splitting of the subtropical high belt, the deepening of BOB trough, the activating of Sri Lanka vortex （twin vortexes in the Northern and Southern Hemispheres）, and the subsequent onset of South China Sea summer monsoon are emphasized.

Mechanism of Thermal Features over the Indo-China Peninsula and Possible Effects on the Onset of the South China Sea Monsoon

The thermal characteristics during the South China Sea (SCS) summer monsoon onset period near the Indo-China Peninsula are analyzed by using the South China Sea Monsoon Experiment (SCSMEX) reanalysis data from 1 May to 31 August 1998 and the NCEP/ NCAR pentad-mean reanalysis data from January 1980 to December 1995. The possible relationships between the anomaly of thermal features near the Indo-China Peninsula and the SCS monsoon onset are investigated, and the mechanism causing the SCS summer monsoon onset is also discussed. Results from the 1998 SCSMEX reanalysis data show that there exists a strong persistent surface sensible heating near the Indo-China Peninsula prior to the SCS monsoon onset, which has apparent low frequency oscillation features. This sensible healing leads lo a warmer center in the lower atmosphere near the Indo-China Peninsula and strong local horizontal temperature and geopotential height gradients which are favorable to strengthening the southwest wind over the Indo-China Peninsula. It is also found that stronger convergent winds at lower levels and stronger divergent winds at high levels appear, which provide a favorable configuration for the development of vertical motion, enhancement of precipitation, and onset of the SCS monsoon. These results can be verified by analysis of the multi-year mean data. Additionally, it is found that the temperature at 850 hPa increases more rapidly over the Indo-China Peninsula than the South China Sea prior to the SCS monsoon onset, which leads to a strengthening of the temperature difference between the Indo-China Peninsula and the South China Sea. Moreover, results from the analysis of the longitudinal temperature and geopotential height differences show that the eastern retreat of the subtropical high over the Indo-China Peninsula during the period of SCS monsoon onset is associated with the temperature increase over the Indo-China Peninsula and the eastern extension of low trough over the Bay of Bengal.

The Summer Monsoon Onset over the Tropical Eastern Indian Ocean: The Earliest Onset Process of the Asian Summer Monsoon

The onset process of the tropical eastern Indian Ocean （TEIO） summer monsoon （TEIOSM） and its relationship with the cross-equatorial flows are investigated via climatological analysis. Climatologically, results indicate that the earliest onset process of the Asian summer monsoon occurs over the TEIO at pentad 22 （April 15-20）. Unlike the abrupt onset of the South China Sea （SCS） summer monsoon, the TEIOSM onset process displays a stepwise advance. Moreover, a close relationship between the TEIOSM development and the northward push of the cross-equatorial flows over 80^-90~E is revealed. A difference vorticity center, together with the counterpart over the southern Indian Ocean, constitutes a pair of difference cyclonic vortices, which strengthens the southwesterly wind over the TEIO and the northerly wind to the west of the Indian Peninsula from the end of March to late May. Therefore, the occurrence of the southwesterly wind over the TEIO is earlier than its counterpart over the tropical western Indian Ocean, and the cross-equatorial flows emerge firstly over the TEIO rather than over the Somali area. The former increases in intensity during its northward propagation, which provides a precondition for the TEIOSM onset and its northward advance.

The Role of Changes in the Annual Cycle in Earlier Onset of Climatic Spring in Northern China

Climatic changes in the onset of spring in northern China associated with changes in the annual cycle and with a recent warming trend were quantified using a recently developed adaptive data analysis tool, the Ensemble Empirical Mode Decomposition. The study was based on a homogenized daily surface air temperature （SAT） dataset for the period 1955–2003. The annual cycle here is referred to as a refined modulated annual cycle （MAC）. The results show that spring at Beijing has arrived significantly earlier by about 2.98 d （10 yr）-1, of which about 1.85 d （10 yr）-1 is due to changes in the annual cycle and 1.13 d （10 yr）-1 due to the long-term warming trend. Variations in the MAC component explain about 92.5% of the total variance in the Beijing daily SAT series and could cause as much as a 20-day shift in the onset of spring from one year to another. The onset of spring has been advancing all over northern China, but more significant in the east than in the west part of the region. These differences are somehow unexplainable by the zonal pattern of the warming trend over the whole region, but can be explained by opposite changes in the spring phase of the MAC, i.e. advancing in the east while delaying in the west. In the east of northern China, the change in the spring phase of MAC explains 40%–60% of the spring onset trend and is attributable to a weakening Asian winter monsoon. The average sea level pressure in Siberia （55°–80°N, 50°–110°E）, an index of the strength of the winter monsoon, could serve as a potential short-term predictor for the onset of spring in the east of northern China.

Asian Summer Monsoon Onset in Simulations and CMIP5 Projections Using Four Chinese Climate Models

The reproducibility and future changes of the onset of the Asian summer monsoon were analyzed based on the simulations and projections under the Representative Concentration Pathways （RCP） scenario in which anthropogenic emissions continue to rise throughout the 21 st century （i.e. RCP8.5） by all realizations from four Chinese models that participated in the Coupled Model Intercomparison Project Phase 5 （CMIP5）. Delayed onset of the monsoon over the Arabian Sea was evident in all simulations for present-day climate, which was associated with a too weak simulation of the low-level Somali jet in May. A consistent advanced onset of the monsoon was found only over the Arabian Sea in the projections, where the advanced onset of the monsoon was accompanied by an increase of rainfall and an anomalous anticyclone over the northern Indian Ocean. In all the models except FGOALS-g2, the enhanced low-level Somali jet transported more water vapor to the Arabian Sea, whereas in FGOALS-g2 the enhanced rainfall was determined more by the increased wind convergence. Furthermore, and again in all models except FGOALS-g2, the equatorial SST warming, with maximum increase over the eastern Pacific, enhanced convection in the central West Pacific and reduced convection over the eastern Indian Ocean and Maritime Continent region, which drove the anomalous anticyclonic circulation over the western Indian Ocean. In contrast, in FGOALS-g2, there was minimal （near-zero） warming of projected SST in the central equatorial Pacific, with decreased convection in the central West Pacific and enhanced convection over the Maritime Continent. The broader-scale differences among the models across the Pacific were related to both the differences in the projected SST pattern and in the present-day simulations.

Interannual variability in the onset of the South China Sea summer monsoon from 1997 to 2014

Using observed and reanalysis datasets,the South China Sea summer monsoon（SCSSM） onset process is analyzed in each year from 1997 to 2014.Regional mean（5-20°N,110-120°E） 850 hPa zonal wind,precipitation,and SST are used as indices to describe SCSSM onset.Three distinct onset types are identified：among the 18 years studied,nine are normal onset years,which are characterized by a well-established westerly wind and associated precipitation over the South China Sea（SCS）;eight are intermittent onset years,in which monsoon precipitation does not occur continuously following the establishment of the westerly wind over the SCS;and one year,2014,is a delayed onset year,in which the western Pacific subtropical high dominates over the SCS after the seasonal transition and prevents the monsoon onset.A comparison of the first two types suggests that a positive SST gradient in the northern Indian Ocean and local SST warming in the SCS are two key factors in the normal SCSSM onset type.With regard to the influence of the El Nino-Southern Oscillation background,there are four late onset years（1997,1998,2007,and 2010） that coincide with El Nino events,but only two early-onset years（1999 and 2012） out of the six years featuring La Nina events.Further analysis suggests that the zonal thermal contrast across the Indian and western Pacific oceans modulates monsoon onset in La Nina years.

Seasonal Forecast of South China Sea Summer Monsoon Onset Disturbed by Cold Tongue La Niña in the Past Decade

It has been suggested that a warm(cold)ENSO event in winter is mostly followed by a late(early)onset of the South China Sea(SCS)summer monsoon(SCSSM)in spring.Our results show this positive relationship,which is mainly determined by their phase correlation,has been broken under recent rapid global warming since 2011,due to the disturbance of cold tongue(CT)La Niña events.Different from its canonical counterpart,a CT La Niña event is characterized by surface meridional wind divergences in the central-eastern equatorial Pacific,which can delay the SCSSM onset by enhanced convections in the warming Indian Ocean and the western subtropical Pacific.Owing to the increased Indian−western Pacific warming and the prevalent CT La Niña events,empirical seasonal forecasting of SCSSM onset based on ENSO may be challenged in the future.

Comparisons of Soil Moisture Datasets over the Tibetan Plateau and Application to the Simulation of Asia Summer Monsoon Onset

The influence of soil moisture on Asian monsoon simulation/prediction was less studied, partly due to a lack of available and reliable soil moisture datasets. In this study, we firstly compare several soil moisture datasets over the Tibetan Plateau, and find that the remote sensing products from the Advanced Microwave Scanning Radiometer for Earth Observing System （AMSR-E） can capture realistic temporal variations of soil moisture better than the two reanalyses （NCEP and ECMWF） during the pre-monsoon seasons. Using the AMSR-E soil moisture product, we investigate the impacts of soil moisture over the Tibetan Plateau on Asian summer monsoon onset based on a Spectral Atmospheric Model developed at IAP/LASG （SAMIL）. Comparison between results with and without the assimilation of remotely sensed soil moisture data demonstrates that with soil moisture assimilated into SAMIL, the land-sea thermal contrast during pre-monsoon seasons is more realistic. Accordingly, the simulation of summer monsoon onset dates over both the Bay of Bengal and South China Sea regions are more accurate with AMSR-E soil moisture assimilated. This study reveals that the application of the soil moisture remote sensing products in a numerical model could potentially improve prediction of the Asian summer monsoon onset.