Anomaly In China Research Articles

Spatial and temporal analysis of daily terrestrial water storage anomalies in China

Spatial and temporal analysis of daily terrestrial water storage anomalies in China

Features of subseasonal concurrent variations between subtropical and polar front jets and their association with temperature anomalies in China

Subseasonal variability of atmospheric circulation in mid-high latitudes is highly correlated to the upper-level jet streams, acting as a major contributor to the global or regional persistent climate anomalies. In this study, the features of subseasonal concurrent variations (SCVs) between East Asian Polar Front Jet (EAPJ) and Subtropical Jet (EASJ), and corresponding atmospheric circulation and temperature anomalies in China are investigated by using the observational data and NCEP/NCAR reanalysis datasets. Results show that the main variability modes of the winter upper-level wind fields on subseasonal time scales are characterized by the meridional shift in opposite directions and out-of-phase variations in the intensity of the EASJ and EAPJ. These concurrent variations between the two jets have a significant oscillation cycle with a period of 10–25 days. Accompanied by the location (intensity) SCV of the two jets, the mid-latitude circulation systems show significant zonal shifts (local intensity changes), resulting in alternations of the atmospheric circulation between zonal and meridional types. The typical meridional circulation is characterized by a strong East Asian trough and its upstream strong high-pressure ridges. Meanwhile, gradient force between Siberian high and the Aleutian low is anomalously strong. As a result, the SCVs between two jets can cause widespread and persistent low temperature anomalies over China, usually lasting more than three days. In the case of the location SCV of the two jets, the low temperature anomalies concentrate in northern China, particularly in north of 40°N. In the case of the intensity SCV of the two jets, the low temperature anomalies occur in most parts of China, notably in south of 40°N. These results are helpful to improve the prediction of atmospheric circulation and temperature anomalies in East Asia during winter.

A Study on the Nonsurgical Correction Treatment Age Window and Long-Term Follow-Up of Infants With Congenital Ear Anomalies in China.

To evaluate the efficacy of ear molding across various initial ages and analyze challenges encountered by infants beyond the optimal treatment age window. A retrospective review of 331 infants (527 ears) treated with EarWell was conducted over 5 years from January 2017 to March 2022 at a single center. The treatment duration of the ear molding, success rate, recurrence rate, and complication rate were analyzed among the 3 age groups. Concentrate on evaluating treatment outcomes for infants with an initial age exceeding 42 days. The mean age at initial treatment was 25±28 days. In addition, it includes a child with cryptotia who is 3.5 years old (1278d). The mean duration of treatment was 7±5 weeks. In the long-term follow-up, the overall treatment success rate was 92%, with 467 ears (88.6%) showing improvement without recurrence, 30 ears (5.7%) experiencing varying degrees of recurrence, and 30 ears (5.7%) showing no improvement or complete recurrence. A total of 20 infants (3%) developed mild skin complications during treatment. Ear molding is a safe and effective option for the treatment of congenital ear anomalies, with a low recurrence rate during long-term follow-up. For infants with congenital auricular anomalies aged over 42 days, ear molding remains a viable option. Treatment success may be influenced by the age at treatment, the subtype of anomalies, and relies on the assessment of a specialized otologist, expert procedural techniques, as well as thorough understanding and cooperation from parents.

3-D Changes of Tropospheric O3 in Central and Eastern China Induced by Tropical Cyclones over the Northwest Pacific: Recent-Year Characterization with Multi-Source Observations

In this study, the multi-year data of meteorology and O3 from remote sensing and ground observations are applied to characterize the 3-D changes of O3 in the troposphere over central and eastern China (CEC) induced by the tropical cyclones (TCs) in the tropical and subtropical ocean regions over Northwest Pacific. The CEC-regional average of near-surface O3 levels is significantly elevated with 6.0 ppb in the large coverage by the TCs in the subtropical ocean, while the TCs in the tropical ocean alter near-surface O3 weakly, indicating the latitudinal-located TCs in the subtropical offshore ocean could largely influence the O3 variations over CEC. The sub-seasonal change with the positive and negative anomalies of near-surface O3 is induced by the tropical TCs from June to July and from August to October. The peripheral circulation of TCs in the subtropical offshore ocean persistently enhances the O3 concentrations over CEC during the season of East Asian summer monsoons. The positive O3 anomalies maintain from the entire troposphere to the lower stratosphere over CEC in the peripheries of subtropical TCs, while the tropical TCs cause the positive O3 anomalies merely in the lower troposphere. The O3 transport and accumulation, photochemical production and stratospheric intrusion are climatologically confirmed as the major meteorological mechanisms of TCs affecting the O3 variations. This study reveals that the downward transport of stratospheric O3 of TCs in the subtropical ocean exerts a large impact on the atmospheric environment over CEC, while the regional O3 transport and photochemical productions dominate the lower troposphere over CEC with less impact of stratospheric intrusion from the TCs in the tropical ocean region. These results present the climatology of tropospheric O3 anomalies in China induced by the TCs over the Northwest Pacific with enhancing our comprehension of the meteorological impact on O3 variations over the East Asian monsoon region.

The reversal of surface air temperature anomalies in China between early and late winter 2021/2022: Observations and predictions

During winter of 2021/2022, the temperature in China is characterized by a warm-to-cold transition, and the average temperature anomaly in February 2022 is −1.6 °C, the coldest February in 2013–2022. We revealed the circulation regimes and physical mechanisms associated with this reversal event and demonstrated the advantage of a regional model downscaling over the use of the global model alone in predicting. In early winter, the warm anomalies are mainly related to an anomalous anticyclonic system downstream of a PNA-like (Pacific–North America) Rossby-wave train induced by La Niña. In late winter, due to the circulation response to the central Pacific warming and negative tropical Indian Ocean Dipole (TIOD), two ‘−＋−’ Rossby-wave trains from high latitudes and the tropical Indian Ocean jointly lead to an anomalous cyclonic system in China. Meanwhile, an anticyclonic blocking system on the northern side of Baikal brings strong and cold air to China. These two systems together cause a significant drop in surface air temperature anomaly in China during the late winter. The Beijing Climate Center climate system model (BCC_CSM1.1 m) can essentially predict this temperature reversal in China about five months in advance. However, the reversal amplitude is weaker due to warm deviations over the tropical Pacific Ocean and equatorial Indian Ocean. Using dynamic downscaling, a regional Climate–Weather Research and Forecasting (CWRF) model correctly predicts the cold SAT anomalies in late winter 2021/2022. The regional model depicts more realistic circulation patterns in East Asia; the anomalous cyclonic system in Inner Mongolia accompanied by the northerly anomalies contribute to a lower-than-normal SAT over China. This study reveals the cooperative effect of wave trains from high latitudes and the tropics on the subseasonal temperature reversal and demonstrates a possible solution to improve the forecast skill by dynamic downscaling according to precise characterization of local surface information.

Heterogeneity of Orofacial Clefts and Associated Anomalies in China.

Despite the large number of affected individuals in China, information on the descriptive epidemiology of orofacial clefts in the Chinese population remains limited. Therefore, the authors aimed to report a detailed clinical classification of orofacial clefts, including microform cleft lip (CL), and associated malformations in patients from a major cleft surgical unit in China. The authors reviewed the medical records of 718 patients who underwent primary cleft repair surgery at their center between December 2016 and April 2023. The sex distribution varied with cleft type and extent, and males had a higher proportion of clefts with increased severity than females. In patients with a unilateral CL, the ratio of left-to-right-sided clefts was 1.85:1. The frequency of associated congenital malformations in patients with microform CL only, overt CL only, CL and palate, and cleft palate only was 8.0%, 7.6%, 14.9%, and 30.9%, respectively. A total of 98 malformations were observed in 69 patients with congenital anomalies of unknown origin. Among these, cardiovascular anomalies were the most common, identified in 27 patients (39.1%), followed by head and neck and musculoskeletal anomalies. The high risk of heart defects highlights the importance of routine echocardiography. Microform CL exhibited increased prevalence and a similar frequency of associated malformations with overt CL, suggesting that this mild phenotype requires further attention by clinicians.

Mispricing and anomalies in China

This study examines arbitrage asymmetry effect on six well-known anomalies in China’s stock market. Using a comprehensive mispricing index constructed based on four popular mispricing measures, we show that anomalies are much more pronounced among overpriced stocks, but weaker or even reversed among underpriced stocks. Results also hold after controlling for several existing mispricing proxies and are stronger among stocks with high arbitrage costs. Our finding suggests that arbitrage costs that mostly result from short-sale constraints hinder correction of overpricing and increase the inefficiency of the stock market.

Finding Anomalies in China

Finding Anomalies in China

The Summertime Circulation Types over Eurasia and Their Connections with the North Atlantic Oscillation Modulated by North Atlantic SST

ERA5 monthly averaged reanalysis data during 1979–2020 are used to analyze the anomalous characteristics of summertime circulation types over Eurasia and their connections with the North Atlantic Oscillation (NAO) modulated by North Atlantic sea surface temperature (SST). A circulation index (CI) is defined to describe the anomalous characteristics of summertime circulation types over the Eurasian mid-high latitude and classify the anomalous circulation into a double-ridge type (DR-type) and double-trough type (DT-type). The results show that these anomalous circulation types are closely related to the variation of the western Pacific subtropical high (WPSH), East Asian subtropical jet (EASJ), South Asia high (SAH) and summer precipitation anomalies in China. There is a significant negative correlation between summer NAO and circulation types over Eurasia. The positive CI is favorable for the southward movement of the EASJ and two positive height anomalies over the Ural Mountains and the Sea of Okhotsk, respectively. Accompanied by moisture convergence and a strong ascending motion over the middle and lower reaches of the Yangtze River Valley (MLYRV), the summer rainfall will be above normal. These patterns are reversed in positive NAO-index years. The connection between the NAO and circulation types over Eurasia is modulated by a tri-pole SST anomaly pattern over the North Atlantic, which may induce the NAO-like atmospheric circulation and strengthen the impacts of the NAO on Eurasian circulation types. A wave train from the North Atlantic to East Asia, which is aroused by the tri-pole SST anomaly pattern, is the potential mechanism for linking summer NAO and circulation types over Eurasia.

Variation patterns and driving factors of regional atmospheric CO2 anomalies in China.

Atmospheric CO2 anomaly (△XCO2) is essential in evaluating regional carbon balance. However, it is difficult to understand △XCO2 variation characteristics due to regional differences. This paper explored the inter-annual and inter-monthly variation patterns of △XCO2 in different regions of China based on satellite observations. The relation model between regional △XCO2 and anthropogenic emissions, gross primary productivity (GPP), wind speed, upwind region's emission, and upwind region's CO2 concentration was established. Results show that the annual average △XCO2 in the northwest and southeast regions is stable at around 0 and 1-2ppm, respectively. Some municipalities directly under the central government and the southern coastal areas showed relatively intense inter-annual fluctuations. Four inter-monthly △XCO2 variation patterns were observed: the northern region has a stable change, the northeast region has the lowest in summer, the southwest region has the highest in summer, and the central region has no obvious change rule. Furthermore, △XCO2 in most areas can be explained by the emission-absorption-transportation model. Significant positive △XCO2 in the southern coastal region in summer may be related to the stable GPP seasonal variation and increased power generation. In the southwestern plateau region, it may be related to the low wind speed and increased soil emission with rising temperature. The stability of the plateau carbon sink and inter-regional cooperation cannot be ignored for improving regional atmospheric environments.

Goodbye to Shell Games: Revisiting Factor Models in China

We show that the estimated shell value of reverse mergers dramatically drops in the out-of-sample periods of Liu et al. (2019, Journal of Financial Economics), which is related to Chinese IPO policy change and system reforms. This structural break is due to the fact that fewer firms choose to go public through a reverse merger. Thus, we document that the shell contamination is considerably mitigated and reconstruct factor models by flexibly eliminating the smallest 30% of stocks. Compared with other popular factor models in the finance literature, our revised CH3/4 model not only has the smallest model specification errors but also helps effectively explain the 25 Fama–French portfolios and most of reported stock anomalies in China.

RETRACTED ARTICLE: Climate abnormal circulation based on monitoring system and marine logistics transportation management

Large scale anomalous circulation is one of the main causes of extreme climate in East Asia. Data mining and statistical analysis of climate reanalysis data are important research methods to understand the characteristics of atmospheric circulation and the occurrence of extreme climate. In this paper, we first use SOM to distinguish the anomalous general circulation models in East Asia from 1979 to 2020. According to the results, we establish the response relationship and monitoring system between various models and climatic factors, and analyze the trend and dynamic mechanism of temperature anomalies in China. Secondly, the atmospheric circulation anomaly model is related to the extreme temperature and precipitation events in East Asia, and studies the climate anomaly characteristics under the complex effects of atmospheric circulation anomaly and monsoon system. The following analysis follows all the basic characteristics of land logistics of marine logistics, but due to the high risk of transportation, transportation time is long, so freight management is different. The existing marine logistics transportation management system has many deficiencies in information exchange, cargo management and transportation. The proposal and application of blockchain technology can effectively supplement it. The consensus mechanism is the core of blockchain technology. The decentralized credit structure and the nonoperability of the consensus mechanism of blockchain can effectively overcome the risk of freedom of contract, optimize the maritime logistics and transportation management model, improve the rationality of the sense of responsibility, ensure the transaction efficiency and transportation safety, and comply with the flexible trend of modern maritime trade. This paper introduces the monitoring system and applies it to the management of climate abnormal circulation and marine logistics transportation, which can effectively improve the management of climate abnormal circulation and marine logistics transportation.

Unsupervised PM2.5 anomalies in China induced by the COVID-19 epidemic

To stop the spread of COVID-19 (2019 novel coronavirus), China placed lockdown on social activities across China since mid-January 2020. The government actions significantly affected emissions of atmospheric pollutants and unintentionally created a nationwide emission reduction scenario. In order to assess the impacts of COVID-19 on fine particular matter (PM2.5) levels, we developed a “conditional variational autoencoder” (CVAE) algorithm based on the deep learning to discern unsupervised PM2.5 anomalies in Chines cities during the COVID-19 epidemic. We show that the timeline of changes in number of cities with unsupervised PM2.5 anomalies is consistent with the timeline of WHO's response to COVID-19. Using unsupervised PM2.5 anomaly as a time node, we examine changes in PM2.5 before and after the time node to assess the response of PM2.5 to the COVID-19 lockdown. The rate of decrease of PM2.5 around the time node in northern China is 3.5 times faster than southern China, and decreasing PM2.5 levels in southern China is 3.5 times of that in northern China. Results were also compared with anomalous PM2.5 occurring in Chinese's Spring Festival from 2017 to 2019, PM2.5 anomalies during around Chinese New Year in 2020 differ significantly from 2017 to 2019. We demonstrate that this method could be used to detect the response of air quality to sudden changes in social activities.

Understanding the cold biases of CMIP5 models over China with weather regimes

Most models in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) underestimate the surface air temperature over China in both winter and summer. Understanding the weather regime in association with the simulated temperature variability is of high interest to get insight into those biases. Based on the weather regime method, we investigated the contributions of large-scale dynamics and non-dynamical processes to temperature biases and inter-model spread. The weather regimes associated with the observational temperature patterns were obtained through a k-means clustering algorithm applied to daily 500 hPa geopotential height anomalies. Here we identified the clustering number of weather regimes using the classifiability and reproducibility indices which can provide the optimal clustering number to obtain objective clustering. Both indices suggested the weather regimes in East Asia can be classified as four clusters in winter (December–January–February) and three in summer (June–July–August). The results indicated that the first and second weather regimes were related to the cold temperature anomalies in China during winter, and the three weather regimes could not effectively classify the temperature patterns during summer. The ensemble mean of 23 CMIP5 models overestimated the occurrence frequencies of the second weather regime, which corresponds to a weaker high latitude westerly jet over East Asia during winter. The 500 hPa geopotential height anomalies and the inter-model spread over the Tibetan Plateau may be associated with the limited ability of the CMIP5 models in simulating the thermal effects of plateau in summer. We also found that the non-dynamical processes had major contribution to the ensemble-mean biases, and the large-scale dynamics played a minor role. The non-dynamical processes substantially affected the inter-model spread, especially over the Tibetan Plateau and the Sichuan Basin, during both winter and summer. The results suggested that improving the simulation of regional processes may help to improve model performance. The use of multi-model mean is recommended since it performs better than most of individual models.

Hydroclimatic anomalies in China during the post-Laki years and the role of concurring El Niño

Arctic is warming at an alarming speed causing accelerated melting of Greenland and rising of sea level, and geoengineering by injecting aerosol into stratosphere (SAI) has been proposed as a backup approach to mitigate warming. However, studies suggest that SAI implementation may have adverse impacts on global especially monsoon precipitation, and Northern Hemisphere high-latitude injections may have disproportionally high effects than tropical injections. The 1783–1784 CE Laki eruption in Iceland provides an analogy to study the climatic and the subsequent socioecological responses to Arctic SAI, and China possesses a rich legacy of documents recording climatic disasters and describing their direct impacts on agriculture and society. Using the most recent summer precipitation reconstructions and the documentary data, this study presents a systemic analysis of the hydroclimatic anomalies as well as the societal and ecological consequences in China following the 1783–1784 CE Laki eruption. The results from multi-proxies show severe drought conditions in eastern China during the post-Laki years, accompanied by large scale locust breakout, famine and human pestilence. The drought and associated disasters first emerged in the North China Plain in 1784 CE, intensified and expanded to the middle and lower reaches of the Yangtze River in 1785 CE. The drought and famine stresses in China are part of the very unsettled climate conditions experienced across the Northern Hemispheric world during the 1780s. By isolating the ENSO-induced precipitation from the reconstructed summer precipitation changes, our results indicate that the Laki eruption did cause severe drought in monsoon China during the next three years. The drought responses in the 1783–1784 were largely counter-balanced by the wetting induced by the concurring strong El Niño event. The results help to enhance our understanding of the hydroclimate consequence of NH high latitude volcanic eruption in China, and the potential role climate internal variation such as ENSO may play in modifying volcanic-induced perturbation.

Diversity of the Coupling Wheels in the East Asian Summer Monsoon on the Interannual Time Scale: Challenge of Summer Rainfall Forecasting in China

Two types of three-dimensional circulation of the East Asian summer monsoon (EASM) act as the coupling wheels determining the seasonal rainfall anomalies in China during 1979–2015. The first coupling mode features the interaction between the Mongolian cyclone over North Asia and the South Asian high (SAH) anomalies over the Tibetan Plateau at 200 hPa. The second mode presents the coupling between the anomalous low-level western Pacific anticyclone and upper-level SAH via the meridional flow over Southeast Asia. These two modes are responsible for the summer rainfall anomalies over China in 24 and 7 out of 37 years, respectively. However, the dominant SST anomalies in the tropical Pacific, the Indian Ocean, and the North Atlantic Ocean fail to account for the first coupling wheel’s interannual variability, illustrating the challenges in forecasting summer rainfall over China.

Fundamental anomalies and the size puzzle in China: A data mining approach

The paper documents the profitable fundamental-based anomalies in China's A-share market and proposes the fundamental-related size puzzle which is converse to prior literature on the US stock market: these anomalies are systematically more pronounced among big stocks than among small stocks. Using the bootstrap approach to control for data mining, the fundamental-related size puzzle strengthens. Further evidence points to the widely perceived view about China's A-share market that for small stocks subject to severe shell-value fluctuations due to IPO constraints, fundamental information is less relevant and hardly incorporated into prices even upon earnings arrival.

Features and Possible Causes of the Extreme Precipitation Anomaly in China During Winter 2019/2020

In this paper, the features and possible causes of extreme precipitation in the winter of 2019/2020 in China are investigated based on the observational station daily dataset provided by the China Meteorological Administration and the ECMWF ERA5 reanalysis dataset. Record-breaking precipitations are found in most areas of China in the winter of 2019/2020, particularly for the north of China. The magnitude of precipitation in south (north) of China in 2019/2020 increase 0.39mm/day (0.15mm/day), about 39.0% (105.5%) compared with the climatological mean. Moisture budget analysis shows that contributions of atmospheric circulation anomaly on horizontal moisture advection and total moisture flux convergence are primarily responsible for the positive anomalies of precipitation in China. Further analysis suggests that the weakened East Asian Trough and the anti-cyclone circulation anomaly over the Sea of Japan favor the transportation of low-level warm and humid airflow from the Northwest Pacific and the East China Sea to the north of China. Meanwhile, the westward movement of the Subtropical High and the Southern Branch Trough anomalies transport low-level warm and humid air from the Bay of Bengal and the South China Sea to south of China. The warm moist air flows northeastward from the East China Sea, Bay of Bengal and the South China Sea while the climatological cold wind flows southeastward, which causes the increase of local precipitation in the winter of 2019/2020. In consideration of the fact that stratospheric polar vortex anomaly has a process of downward propagation to the troposphere, it is of great significance to study the changes of the stratosphere and the relationships between stratosphere and troposphere.

Variations in the annual cycle of the East Asian monsoon and its phase-induced interseasonal rainfall anomalies in China

The East Asian monsoon (EAM) exhibits a robust annual cycle with significant interannual variability. Here, the authors find that the EAM annual cycle can be decomposed into the equinoctial and sol...

Evaluating the accrual anomaly in the Chinese stock market with the decomposition method

ABSTRACT We evaluate the explanations for accrual anomaly in the Chinese stock market using the decomposition method. The results show that institutional ownership best explains the accrual anomaly with an explanatory power of about 46%, equity growth (EG) explains 12% of the anomaly, and the residual fraction of around 32% is unexplained by any candidate explanations. Our findings indicate that the naïve investor fixation hypothesis is favored to explain the accrual anomaly in China, and the existing explanations cannot fully explain the anomaly.