Lixia Zhang

Institute of Atmospheric Physics · LASG

Understanding global monsoon (GM) variability and projecting its future changes relies heavily on climate models. However, climate models generally show pronounced biases in GM simulations, and the reasons for this remain unclear. Here, we evaluate the performance of 20 pairs of climate models that participated in both the Coupled Model Intercompar...

The precipitation changes in arid and semi-arid Central Asia have great impacts on the local fragile ecosystem. The summer precipitation in Central Asia shows obvious interannual variations, but the corresponding crucial moisture transporting processes remain unclear. Therefore, this study employs the Lagrangian model FLEXPART to achieve this goal....

Globally, 2023 was the warmest observed year on record since at least 1850 and, according to proxy evidence, possibly of the past 100 000 years. As in recent years, the record warmth has again been accompanied with yet more extreme weather and climate events throughout the world. Here, we provide an overview of those of 2023, with details and key b...

The Yangtze River Valley (YRV) experienced an unprecedented heatwave in midsummer of 2022. Still, the detailed physical processes involved in the influence of abnormal large-scale atmospheric circulation on the heatwave remain unexplored. Here, we show that the positive meridional gradient of anomalous atmospheric moisture at the middle-lower tropo...

The modern East Asian summer monsoon (EASM) features an extension from tropical to subtropical areas. However, the fundamental process that determines the northward extension of EASM in the geological history remains unclear. Here, we showed evidence from proxy data, climate modeling, and theoretical solutions that the northward extension of EASM t...

In the latter half of the twentieth century, a significant climate phenomenon “diurnal asymmetric warming” emerged, wherein global land surface temperatures increased more rapidly during the night than during the day. However, recent episodes of global brightening and regional droughts and heatwaves have brought notable alterations to this asymmetr...

Extreme weather events and their consequential impacts have been a key feature of the climate in recent years in many parts of the world, with many partly attributed to ongoing global-scale warming. The past year, 2022, has been no exception, with further records being broken. The year was marked by unprecedented heatwaves and droughts with highly...

The Yangtze River Valley (YRV) experienced an unprecedented heatwave in midsummer of 2022, but the detailed physical processes involved in the influence of anomalous large-scale atmospheric circulation on the heatwave remain unknown. Here, we show that the positive meridional gradient of anomalous atmospheric moisture at the middle-lower tropospher...

During summer 2021, Western North America (WNA) experienced an unprecedented heatwave with record-breaking high temperatures associated with a strong anomalous high-pressure system, i.e., a heat dome. Here, we use a flow analog method and find that the heat dome over the WNA can explain half of the magnitude of the anomalous temperature. The intens...

Both the attribution of historical change and future projections of droughts rely heavily on climate modeling. However, reasonable drought simulations have remained a challenge, and the related performances of the current state-of-the-art Coupled Model Intercomparison Project phase 6 (CMIP6) models remain unknown. Here, both the strengths and weakn...

In the summer (July and August) of 2022, unprecedented heat wave occurred along the Yangtze River Valley (YRV) over East Asia while unprecedented flood occurred over western South Asia (WSA), which are located on the eastern and western sides of Tibetan Plateau (TP). Here, by analyzing the interannual variability based on observational and reanalys...

Droughts are one of the climate extremes that occur frequently in drylands, constraining the terrestrial carbon uptake and water cycle processes. Studies about the long-term changes in the effect of drought stress on dryland ecosystems under global warming are still insufficient so far. Here we comprehensively investigate long-term changes in droug...

The Afro-Asian summer monsoon (AfroASM) sustains billions of people living in many developing countries covering West Africa and Asia, vulnerable to climate change. Future increase in AfroASM precipitation has been projected by current state-of-the-art climate models, but large inter-model spread exists. Here we show that the projection spread is r...

The year 2021 was recorded as the 6th warmest since 1880. In addition to large-scale warming, 2021 will be remembered for its unprecedented climate extremes. Here, a review of selected high-impact climate extremes in 2021, with a focus on China, along with an extension to extreme events in North America and Europe is presented. Nine extreme events...

Central Asia (CA; 35°–55°N, 55°–90°E) has been experiencing a significant warming trend during the past five decades, which has been accompanied by intensified local hydrological changes. Accurate identification of variations in hydroclimatic conditions and understanding the driving mechanisms are of great importance for water resource management....

Precipitation changes over the Tibetan Plateau (TP), “Asian Water Tower”, greatly affect water resources of the surrounding countries. A dipole pattern in summer precipitation trend over the TP is observed for 1961–2013, increasing over the north TP (NTP) and decreasing over the south TP (STP). Since the TP is one of the most vulnerable regions to...

The observational records have shown a strengthening of the Pacific Walker circulation (PWC) since 1979. However, whether the observed change is forced by external forcing or internal variability remains inconclusive, a solid answer to more societal relevantly question of how the PWC will change in the near future is still a challenge. Here we perf...

Despite local emission reductions, severe haze events remain a serious issue in Beijing. Previous studies have suggested that both greenhouse gas increases and aerosol decreases are likely to increase the frequency of weather patterns conducive to haze events. However, the combined effect of atmospheric circulation changes and aerosol and precursor...

The summer of 2020 recorded a record-breaking flood due to excessive mei-yu rain falling over the Yangtze River Valley (YRV). Using the Lagrangian model FLEXPART, this paper investigates moisture sources and transport processes behind this extreme event. Based on climate data from 1979 to 2019, the air-particle (an infinitesimally small air parcel)...

Highly unusual amounts of rainfall were seen in the 2020 summer in many parts of China, Japan, and South Korea. At the intercontinental scale, case studies have attributed this exceptional event to a displacement of the climatological western North Pacific subtropical anticyclone, potentially associated Indian Ocean sea surface temperature patterns...

Southeast Asian monsoon region is regularly stricken by drought, but less attention is paid due to its slow-onset and less visual impact. This study investigated the observed drought changes over Southeast Asian monsoon region and impacts of anthropogenic forcing using the Coupled Model Intercomparison Project Phase 6 models. We revealed an increas...

Every summer in eastern Asia, the combined effects of complex topography, multiple potential moisture sources and a mixture of sub-tropical and mid-latitude dynamics produces an environment, in which subtle differences in spatial patterns of atmospheric circulation can profoundly affect the geographic distribution of rainfall. Understanding and qua...

Air pollution is a major issue in China and one of the largest threats to public health. We investigated future changes in atmospheric circulation patterns associated with haze events in the Beijing region and the severity of haze events during these circulation conditions from 2015 to 2049 under two different aerosol scenarios: a maximum technical...

Despite local emission reductions, severe haze events remain a serious issue in Beijing. Previous studies have suggested that both greenhouse gas increases and aerosol decreases are likely to increase the frequency of weather patterns conducive to haze events. However, the combined effect of atmospheric circulation changes and aerosol and precursor...

The Asian subtropical westerly jet (AWJ) exerts crucial influences on Eurasian continent weather and climate. This paper analyzes the advantages and limitations of CRA-40, which is China’s first generation 40-yr (1979–2018) global atmosphere and land reanalysis product, in describing the characteristics of AWJ, compared with the ECMWF Reanalysis ve...

China Meteorological Administration (CMA) recently released its 40-yr (1979–2018) global Chinese reanalysis (CRA-40) dataset. To assess performance of the CRA-40 data in quantifying the regional water cycle, contributions of local and remote atmospheric moisture fluxes to precipitation in East China derived from CRA-40 are compared with those deriv...

Air pollution is a major issue in China and one of the largest threats to public health. We investigated future changes in atmospheric circulation patterns associated with haze events in the Beijing region, and the severity of haze events during these circulation conditions, from 2016 to 2049 under two different aerosol scenarios: a maximum technic...

This paper introduces the Flexible Global Ocean–Atmosphere–Land System Model: Grid-Point Version 3 (FGOALS-g3) and evaluates its basic performance based on some of its participation in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) experiments. Our results show that many significant improvements have been achieved by FGOALS-g3...

Changes in global land monsoon (GLM) precipitation determine the local water resource, affecting two thirds of global population. The future changes in GLM summer precipitation and the sources of projection uncertainty under four scenarios are investigated using the Coupled Model Intercomparison Project Phase 6 (CMIP6) models. The GLM summer precip...

Identifying the origin of moisture is a key process in revealing the formation mechanisms of precipitation, but the moisture sources for Central Asia have not been well documented in previous studies. In this work, we employ the Lagrangian model FLEXPART over 2011-2019 to address this question. Multiple observational products indicate that the time...

Changes in monsoon precipitation have profound social and economic impacts as more than two-thirds of the world’s population lives in monsoon regions. Observations show a significant reduction in global land monsoon precipitation during the second half of the 20th century. Understanding the cause of this change, especially possible anthropogenic or...

This paper reviews the current knowledge on detection, attribution and projection of global and regional monsoons (South Asian, East Asian, Australian, South American, North American, and African) under climate change. Monsoon rainfall has profound economic and societal impacts for more than two-thirds of the global population. Here we provide a r...

A stronger than global mean warming trend is projected over Central Asia in the coming century. Based on the historical simulations and projections under four combined scenarios of the Shared Socioeconomic Pathways and the Representative Concentration Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) provided by 15 models from the Sixth Phase of...

The Indian summer monsoon (ISM) rainfall affects a large population in South Asia. Observations show a decline in ISM rainfall from 1950-1999 and a recovery from 1999-2013. While the decline has been attributed to global warming, aerosol effects, deforestation, and a negative-to-positive phase transition of the Interdecadal Pacific Oscillation (IPO...

Abstract The global land monsoon region has the highest land cloud amount in the world affecting two thirds of the world's population. Understanding the characteristics of cloud‐radiation relies heavily on satellite data set, while few studies have addressed the advantages and weaknesses of current existing satellite data sets in estimating the clo...

Arid Central Asia is highly vulnerable to extreme climate events. Information on potential future changes in extreme climate events in Central Asia is limited. In this study, the performances of models from the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating climatological extremes in Central Asia are first evaluated, and a bias...

The Tibetan Plateau is known as the “Asian Water Tower”. In the past 50 years, global warming has accelerated the water cycle over the Asian Water Tower. The current understanding on the key processes of water vapor transport over the Asian Water Tower and the behind mechanisms are reviewed in this paper, via the climatology, long-term trend, and i...

The ecosystem and societal development in arid Central Asia are highly vulnerable to climate change. During the past five decades, significant warming occurs in Central Asia, but whether the influence of anthropogenic forcing is detectable remains unclear. Therefore, we employ the optimal fingerprinting method to address the question in this study....

The Northeast Farming Region (NFR) of China is a critically important area of maize cultivation accounting for ~30% of national production. It is predominantly rain fed, meaning that adverse climate conditions such as drought can significantly affect productivity. Forewarning of such events, to improve contingency planning, could therefore be highl...

The mechanisms of short-lived precipitation extremes in boreal summer over the middle–lower reaches of the Yangtze River Basin (MLYRB) during 1961–2014 are explored using gridded observational and reanalysis datasets. Daily precipitation extremes are defined by the 75th and 95th percentiles and identified for selected regions in the MLYRB. Moisture...

Any skillful prediction is of great benefit to North China, a region that is densely populated and greatly impacted by droughts. This paper reports potential predictability of North China summer drought 1 month ahead based on hindcasts for 1961–2005 from the “ENSEMBLES” project. Correlation scores of the standardized precipitation–evapotranspiratio...

An integrated picture of the future changes in the water cycle is provided focusing on the global land monsoon (GLM) region, based on multimodel projections under the representative concentration pathway 8.5 (RCP8.5) from phase 5 of the Coupled Model Intercomparison Project (CMIP5). We investigate the reservoirs (e.g., precipitable water, soil mois...

This paper reports a consistent seesaw relationship between interdecadal precipitation variability over North China and the Southwest United States, which can be found in observations and simulations with several models. Idealized model simulations suggest the seesaw could be mainly driven by the interdecadal Pacific oscillation (IPO), through a la...

The Paris Agreement set a goal to keep global warming well below 2 °C and pursue efforts to limit it to 1.5 °C. Understanding how 0.5 °C less warming reduces impacts and risks is key for climate policies. Here, we show that both areal and population exposures to dangerous extreme precipitation events (e.g., once in 10- and 20-year events) would inc...

The sensitivity of the representation of the global monsoon annual cycle to horizontal resolution is compared in three AGCMs: the Met Office Unified Model-Global Atmosphere 3.0; the Meteorological Research Institute AGCM3; and the Global High Resolution AGCM from the Geophysical Fluid Dynamics Laboratory. For each model, we use two horizontal resol...

In a globally warming world, subtropical regions are generally expected to become drier while the tropics and mid–high latitudes become wetter. In line with this, Southwest China, close to 25°N, is expected to become increasingly prone to drought if annual mean precipitation decreases. However, despite this trend, changes in the temporal distributi...

The ecosystem and societal development over arid Central Asia, the core connecting region of the Silk Road Economic Belt, are highly sensitive to climate change. The results derived from multiobservational datasets show that summer precipitation over Central Asia has significantly increased by 20.78% from 1961 to 2013. It remains unclear whether an...

Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a central focus of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmos...

The East Asian Summer Monsoon (EASM), which has profound societal and economic impacts in China, has exhibited multiple time-scale variabilities. Climate models play an irreplaceable role in understanding the past changes and predicting/projecting the future changes in the EASM. However, current state of the climate models still shows evident biase...

Persistent drought is a major meteorological disaster causing vast agricultural damage and long-term regional water crises. Over north China, this type of drought tends to begin in spring and to persist until summer with severe societal impacts. This paper aims to identify the large-scale dynamic drivers of the prolonged spring-summer drought (PSSD...

Extreme high-temperature events have large socioeconomic and human health impacts. East Asia is a populous region, and it is crucial to assess the changes in extreme high-temperature events in this region under different climate change scenarios. The Community Earth System Model low-warming experiment data were applied to investigate the changes in...

The Coupled Model Intercomparison Project (CMIP) is an international community-based infrastructure that supports climate model intercomparison, climate variability, climate prediction, and climate projection. Improving the performance of climate models over East Asia and the western North Pacific has been a challenge for the climate-modeling commu...

The Tibetan Plateau (TP) plays an essential role in the global hydrological cycle. Unlike the well-recognized surface warming, changes in precipitation over the TP and the underlying mechanisms remain ambiguous. A significant increase in the amount of precipitation over the southeastern TP in May over 1979–2014 (13.46% decade−1 of the climatology)...

The frequency of extreme summer drought has been increasing in North China during the past sixty years, which has caused serious water shortages. It remains unclear whether anthropogenic forcing has contributed to the increasing extreme droughts. Using the National Centers for Environmental Prediction and the National Center for Atmospheric Researc...

Global warming increases the moisture holding capacity of the atmosphere and consequently the potential risks of extreme rainfall. Here we show that maximum hourly summer rainfall intensity has increased by about 11.2% on average, using continuous hourly gauge records for 1971–2013 from 721 weather stations in China. The corresponding event accumul...

Climate models tend to overestimate percentage of the contribution (to total precipitation) and frequency of light rainfall while underestimate the heavy rainfall. This article investigates the added value of high resolution of atmospheric general circulation models (AGCMs) in simulating the characteristics of global precipitation, in particular ex...

Drought affects virtually every region of the world, and potential shifts in its character in a changing climate are a major concern. This article presents a synthesis of current understanding of meteorological drought, with a focus on the large-scale controls on precipitation afforded by sea surface temperature (SST) anomalies, land surface feedba...

A summary of the development of observational metrics for gauging model performance over the East Asian–western Pacific domain is presented. The proposed metrics focus on the multi-scale features of the East Asian summer monsoon (EASM), ranging from diurnal cycle to intraseasonal, interannual, and interdecadal variability, as well as the distributi...

During 1979-2004, the East Asian summer precipitation has experienced another significant decadal shift around the early 1990s. Based on three radiosonde temperature datasets and four reanalysis datasets, this paper examines the decadal change of the East Asian summer tropospheric temperature around the early 1990s. The results show that the meridi...

East Asia is greatly impacted by drought. North and southwest China are the regions with the highest drought frequency and maximum duration. At the interannual time scale, drought in the eastern part of East Asia is mainly dominated by two teleconnection patterns (i.e., the Pacific-Japan and Silk Road teleconnections). The former is forced by SST a...

The performance of Version 2 of the Flexible Global Ocean-Atmosphere-Land System model (FGOALS-s2) in simulating global monsoon precipitation (GMP) was evaluated. Compared with FGOALS-s1, higher skill in simulating the annual modes of climatological tropical precipitation and interannual variations of GMP are seen in FGOALS-s2. The simulated domain...

Here, the performance of FGOALS-s2 and FGOALS-g2 in simulating the Asian monsoon, the western African monsoon and the global monsoon was evaluated. Generally speaking, both the models simulated the monsoon climatology reasonably well. The simulated major monsoon rainfall centers and corresponding atmospheric circulation are consistent with those in...

The development of coupled earth/climate system models in China over the past 20 years is reviewed, including a comparison with other international models that participated in the Coupled Model Intercomparison Project (CMIP) from phase 1 (CMIP1) to phase 4 (CMIP4). The Chinese contribution to CMIP is summarized, and the major achievements from CMIP...

An overview of Chinese contribution to Coupled Model Intercomparison Project-Phase 5 (CMIP5) is presented. The performances of five Chinese Climate/Earth System Models that participated in the CMIP5 project are assessed in the context of climate mean states, seasonal cycle, intraseasonal oscillation, interannual variability, interdecadal variabilit...

Using the reanalysis data and 20th century simulation of coupled model FGOALS_gl developed by LASG/IAP, we identified two distinct interannual modes of Northwestern Pacific Subtropical Anticyclone (NWPAC) by performing Empirical Orthogonal Function (EOF) analysis on 850 hPa wind field over the northwestern Pacific in summer. Based on the associated...

Based on four radiosonde data sets and three reanalysis data sets, the long‐term tropospheric temperature changes over China for the period 1958–2001, and the uncertainties are analyzed. The results from all data sets, except for HadAT2 and National Centers for Environmental Protection 20th Century Reanalysis data (NCEP‐20CR), show a significant wa...

Tropical cyclone genesis potential index (GPI) is a useful metric for gauging the performance of global climate models in the simulation of tropical cyclone (TC) genesis. The performance of LASG/IAP AGCM GAMIL2.0 in the simulation of GPI over the western North Pacific (WNP) is assessed in this paper. Since GPI depends on large scale environmental f...

By using 55-yr NCEP-NCARreanalysis data, two dominant interannual variabilitymodes of summer uppertropospheric (500-200 hPa) temperature over East Asia are identified. The first empirical orthogonal function (EOF1) mode in its positive sign features amonopole cooling anomaly, while the secondmode (EOF2) features ameridional dipolemode, with the pos...

The interannual variability of the boreal winter (DJF) Hadley Cell strength during 1979–2008 is investigated using NCEP/NCAR reanalysis data. The results of AMIP simulation of LASG/IAP AGCM GAMIL2.0 are compared against the reanalysis data. Both the reanalysis data and the simulation show that the interannual variability of the Hadley Cell strength...

Contributions of natural and anthropogenic forcing factors to the temperature change in the twentieth-century are evaluated with a climate system model named FGOALS_gl, which was developed by LASG/IAP. Two sets of numerical experiments were done. The first is an all-forcing in which both the natural forcing agents and the anthropogenic forcing agen...

To compare differences among the Medieval Warm Period (MWP), Little Ice Age (LIA), and 20th century global warming (20CW), six sets of transient and equilibrium simulations were generated using the climate system model FGOALS_gl. This model was developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Flui...

Changes of global land monsoon precipitation are assessed by using three sets of rain-gauge precipitation data for the period of 1901–2002 compiled by GPCC, CRU and Dai-dataset, respectively. The three datasets show consistent long-term changes of precipitation over the monsoon region with slightly different amplitudes. During 1901–2001, global lan...

Changes of global land monsoon precipitation are examined by using three sets of rain-gauge precipitation data for the period of 1901-2001 compiled by GPCC, CRU and Dai, respectively. The three datasets show consistent long-term changes of precipitation over the monsoon region with slightly different amplitudes. During 1901-2001, global land monsoo...

This paper evaluates the performance of a coupled general circulation model FGOALS−s1.1 developed by LASG/IAP in simulating the annual modes of tropical precipitation. To understand the impacts of air-sea coupling on the annual modes, the result of an off-line simulation of the atmospheric component of FGOALS−s1.1, i.e., LASG/IAP atmospheric genera...

1] This study reports the changes of global land monsoon coverage and monsoon rainfall accumulation. We showed that the combination of monsoon area and rainfall intensity change has led to an overall weakening trend of global land monsoon rainfall accumulation during the last 54 years. This decreasing tendency is mainly caused by the North African...