Guoyu Ren

• PhD
• Chair Professor at China University of Geosciences/National Climate Center

Precipitation is one of the crucial climatic variables that has significant impact on the natural and human systems, with several important sectors of the Earth's system responding to its spatiotemporal variability. Consequently, various studies are conducted on global and regional scales to evaluate changes and trends in precipitation, with more e...

An enhanced extreme precipitation (EXP) in or near cities compared to rural areas has been widely observed and verified in individual urban sites. However, at a sufficiently large region, the robustness of evidence for the urbanization contribution to the estimate of EXP trends is still lacking. Here, we present clear evidence from observational re...

The Yangtze River Basin has always been one of China's most densely populated regions and one of the most active in agricultural activities. Although previous studies have examined extreme climate events in the Yangtze River Basin, the main factors influencing the long-term changes in the region’s key agricultural frost days (FD) and summer days (S...

This article examines the impact of urbanization on extreme temperature trends as estimated from 658 national ground meteorological observation stations in the Yangtze River Basin over the past 60 years. The main findings include: ①The annual mean, maximum, and minimum temperatures all display a significant upward trend, accompanied by a decline in...

Recently, the extreme droughts and floods in the East Asian monsoon region have shown new characteristics. However, the observational data series from instrumental records are too short to meet the needs of research on multi-decadal to centennial scale precipitation or drought/flood variability. It is thus important to reconstruct the past multi-ce...

Snow cover days (SCD) have increased significantly in winter on the Western Kunlun Mountains and Eastern Pamir Plateau (hereafter referred to as KMPP for short), however the causes have not been well understood so far. Here, we use remote sensing data to analyze the abnormal increase in SCD on the KMPP and explore its causes from the perspective of...

This is an introduction to the collection of Climatic Change "Historical and Recent Change in Extreme Climate over East Asia". The articles in the collection can be accessed at: https://link.springer.com/collections/hehacjebcg.

Daily meteorological observation data of the early period (pre-1950) were critically important for investigating the long-term trends and multi-decadal scale variability of extreme climate events. The high-resolution surface air temperature (SAT) data for time period before 1950 are lacking in China. We extended the SAT observations of China back t...

人们十分关心，在全球变暖的背景下，全球和区域极端天气事件是不是增多了？本书通过作者团队近二十余年的研究，告诉读者，学术界和公众对这个问题都有认知上的偏差。观测事实是，自从20世纪中期以来，至少在中国大陆地区，极端天气气候事件频次，有增有减，以减少为多。作者对主要类型极端天气气候事件变化的原因，以及人们形成认知偏差的原因，给出了简明解释。 People are very concerned about whether there has been an increase in global and regional extreme weather events in the context of global warming. This book is written based on nea...

This is the preface of our recently published book Atlas of Snowfall and Snow Cover in China, which presents a brief introduction to the background and contents of the book. The atlas was compiled with the support of the Ministry of Science and Technology of China (2018YFA0605603), and published by China Meteorological Press in Beijing in 2024.

Urbanization has caused additional warming in the surface air temperature records of most meteorological stations in China, leading to a positive bias in the air temperature observation trends. However, previous studies have shown that urbanization in northern Xinjiang may have caused a cooling trend in the air temperature data series at national s...

The cryosphere is one of the important components of the Earth's climate system, and snowfall and snow cover are the key geophysical processes in the cryosphere, which have important effects on the formation of glaciers and the change and variability of the climate system. In addition, snowfall and snow cover are not only valuable climate resources...

Separating existing historical precipitation data into solid and liquid precipitation remains a challenge in the study of climate change, extreme precipitation, and hydrological modelling. Based on historical daily air temperature and precipitation data, as well as visual observations of precipitation phase (weather phenomena records) in China main...

Understanding the characteristics of minute‐scale short‐duration intense rainfall and its possible link with urbanization is valuable for addressing urban climate change and evaluating biases in high‐resolution historical precipitation data series. This study analyses the long‐term trends of rainy‐season minute‐scale intense rainfall events at diff...

The present study aims to detect the variation of precipitation extreme events in the northern part of the Korean Peninsula during 1961–2020, as well as to investigate its possible causes, based on daily precipitation data from 37 representative stations. Nonparametric tests such as Mann‐Kendall and Kendall‐tau were used to detect statistical chara...

The intensity and direction of elevation-dependent warming (EDW) could vary in different parts of the mountain, while less attention is paid to the local EDW effect. The Tibetan Plateau (TP) and the T'ai-hang & Lvliang Mountains in Shanxi Province of China (TLMsx) were taken as cases to examine the relationship between EDW and the long-term trend o...

Seasonal cycle is the crucial intra-annual climate pattern, which is important for global and regional agricultural practice. The global land surface has witnessed a significant increase in air temperature over nearly half a century. As a result, various seasonal indicators associated with surface air temperature, such as the lengths, start dates a...

Land desertification is a major ecological challenge facing the world, profoundly affecting human life and sustainable development. As one of the countries with the most severe desertification issues across the world, China has a population of 580 million living on 6.6 million square kilometers of dry land. The climate in northern China has changed...

Plain Language Summary Human influences have been identified in the observed warming quantified by surface air temperature (SAT), but SAT alone is inadequate as a metric for human thermal comfort. Here we focus on human‐perceived temperature (HPT), which describes the “feels‐like” equivalent temperature by considering the joint effects of temperatu...

Using terms with the same meaning is a precondition of academic exchange and coordinated international actions to cope with the global climate issue. However, the understanding and usage of some terms in the climate change field are incompatible among researchers, policymakers, and publics. In particular, the Intergovernmental Panel on Climate Chan...

In the past century, local-scale warming caused by a strengthening urban heat island effect has brought inevitable systematic bias to observational data from surface weather stations located in or near urban areas. In this study, the land use situation around U.S. Climate Reference Network (USCRN) stations was used as a reference for rural station...

In recent years, several rare extreme weather and climate events that have occurred in China have attracted widespread attention from the public. The "7.20" extremely heavy rainstorm in Zhengzhou in 2021, the abnormal high temperature and heat wave in the Yangtze River basin in the summer of 2022, and the "7.31" extremely intense rainstorm in Beiji...

Based on the daily ground surface air temperature, ground surface temperature (0-cm soil temperature) and precipitation data of 17 national meteorological stations in Shijiazhuang area, Hebei province, China, from 1972 to 2021, variation characteristics of ground-air temperature difference and the relationship between ground-air temperature differe...

With increased global warming, heatwaves are expected to become more intense, frequent, and persistent. Although the spatiotemporal characteristics of heatwaves have been extensively studied, the vast majority of these studies have solely used near-surface air temperatures, particularly daily maximum temperatures (Tmax), to identify heatwaves. Give...

The near-surface air temperature lapse rate (SATLR) is a result of surface energy balance, and the long-term trend of SATLR is linked to elevation-dependent warming (EDW). The long-term trend of SATLR in China’s mainland was examined in the present study. It was found that the regional average values of annual, autumn, and winter SATLR anomalies in...

Plain Language Summary The canopy urban heat island (CUHI) phenomenon can affect human health and the ecological environment, and its multi‐timescale variability brings great uncertainty to the study of urban climates worldwide. In this study, taking the megacity of Beijing as an example, a novel short‐time Fourier transform (STFT) method was used...

The construction and analysis of daily temperature data series in long enough a time period is important to understand decadal to multi-decadal variability and changing trends in extreme temperature events. This paper reports a new analysis of extreme temperature indices over the last 140 yr in Wuhan, China, with an emphasis on changes in extreme h...

In the present paper, we made an investigation of extreme rainfall events for 1860―1909 in the Korean Peninsula, and the possible atmospheric circulation state by comparing recent rainfall variability with atmospheric circulation indices. Major historical rainfall records and flood damage records since the mid-19th century and modern rainfall and g...

Using the drought and flood grades, the historical co‐drought probabilities of the water source area (i.e., the Upper Hanjiang River or UH) and the receiving area (i.e., North China or NC) of the Middle Route of the South‐to‐North Water Diversion project from 1470 to 2017 were analyzed. It was found that there is relatively high possibility for co‐...

Applying surface air temperature (2-m) data observed from automatic weather stations from September 2017 to August 2019 and the long-term surface air temperature data from 1960 to 2019, we analyzed spatial and temporal characteristics of urban heat island intensity (UHII) in Xiamen city, southern China, and urbanization effect on trends of surface...

This article is completed on the basis of the survey of changes in the observational environment of the Hexi Corridor and North Xinjiang meteorological stations in 2021 summer, and it is expected to provide a reference for understanding changes in meteorological observation environment and the representativeness of stations in the Northwest China a...

Tornadoes are the most destructive meso-small-scale strong convective weather on Earth. At present, however, the temporal change of tornadoes in a subcontinental region like mainland China is still controversial. Here, we report an analysis of the spatial-temporal pattern and long-term trend of tornadoes in mainland China from 1961 to 2013 based on...

The reliability of climate change detection and research is significantly impacted by the inhomogeneity of surface climate observation data. However, there is an ongoing debate regarding whether comprehensive homogenization has been performed in large-scale homogenized data sets. In this study, we examined the homogeneity of the original maximum an...

This collection includes extended abstracts of 198 papers submitted to, and presented on, the "Seventh Symposium on Monitoring and Detection of Regional Climate Change" held in Urumqi, 9-12, 2023.

This is a Chinese monograph on climate change monitoring and detection technology, methods and principles. Its main contents include: interpretation and discrimination of commonly used scientific and technical terms related to climate change; basic procedures of climate change monitoring services and detection research; global and national referenc...

This is a brief review of studies on urban climatology and urban climate change conducted by our group over the last 20 years, presented at a forum organized by Journal of Meteorological Research (JMR) on 18, Aug. 2023. Concept of urban climate change was put forward in 2015, but the studies of anthropogenic urban climate change, which is the major...

The "Seventh Symposium on Monitoring and Detection of Regional Climate Change", co-sponsored by China University of Geosciences (Wuhan), National Climate Center, Climate Change and Low-Carbon Development Committee of the Chinese Meteorological Society, and Xinjiang Meteorological Bureau, undertaken by Xinjiang Climate Center and Xinjiang Meteorolog...

The magnitude of long-term surface climate warming over some regions, such as the Chinese mainland, is still uncertain due to the lack of observational data early in the 20th century. In this study, the monthly data series of the average, maximum, and minimum temperatures in the Chinese mainland during 1901-2020 were constructed based on the daily...

Globally, marine heatwaves (MHWs) are becoming more common, more intense, and longer-lasting. They could have a large ecological and societal impact when compounded by low oxygen concentrations or high acidity. Here, using a high-resolution satellite product and reanalysis datasets, we investigated the characteristics of the MHW at northern Yellow...

The heating and cooling energy consumption levels of urban buildings account for a large and rapidly growing proportion of the total end-use energy consumption of society. The urban heat island (UHI) effect is an important factor influencing the spatiotemporal variations in the heating and cooling energy consumption levels of buildings. However, th...

The land surface air temperature in Asia is increasing significantly since the 1950s. However, the current understanding of Asian warming since 1901 in observations and simulations is still poor. Based on a newly developed observation dataset with 2,658 stations and Coupled Model Intercomparison Project Phase 5/6 (CMIP5/6) output data in Asia, here...

Extreme precipitation in monsoon region of China can cause a variety of weather and climate disasters, and its long-term change has a significant impact on human life and social production. However, due to the lack of high-resolution precipitation data in the early 20th century, the variation characteristics and causes or mechanisms of extreme prec...

Asia is the largest continent in the world and home to 4.7 billion people. Climate change on this continent, therefore, attracts a significant amount of attention from scientists and policy-makers. However, observational studies of long-term climate change over the continent as a whole are lacking. Using updated, homogenized observational data from...

ABSTRACT: To better understand the characteristics of long-term change and variability in regional extreme precipitation and to examine possible regional responses to global climate warming, we analyzed temporal and spatial patterns of precipitation and extreme precipitation index changes in the Yangtze River Basin (YRB) over the last 120 yr. Based...

Increasing of evidence suggests that rapid urbanization modifies precipitation and increases atmospheric instability in urban areas mainly due to urban heat island (UHI)-induced thermal effects and urban building-induced dynamic effects. However, few studies focus on the impact of urbanization on the diurnal variations in urban rainfall in terms of...

Based on the daily observational data of air temperature and the soil temperature at a depth of 0–320 cm at the Shijiazhuang urban meteorological station and two nearby rural stations from 2009 to 2012, urban heat island (UHI) effect from the canopy to the surface and deep layers of soil at Shijiazhuang urban station were compared and analyzed. The...

A Lagrangian model—the Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT)—is used to quantify changes in moisture sources and paths for precipitation over North China’s Henan Province associated with tropical cyclone (TC) over the western North Pacific (WNP) during July–August of 1979–2021. During TC-active periods, an anomalou...

adw: Angular Distance Weighting Interpolation The irregularly-spaced data are interpolated onto regular latitude-longitude grids by weighting each station according to its distance and angle from the center of a search radius.

Examining large-scale characteristics of the difference between ground surface temperature (GST) and surface air temperature (SAT) and its long-term trend will help understand land surface energy exchange and the effect of land-atmosphere interaction on climate change and variability. Based on a homogenized monthly dataset of GST and SAT from 1961...

Based on the records of drought and flood in Chinese historical documents and precipitation data during the instrumental period, and by using the five-grade classification method, this study reconstructs the drought and flood grades in the Hanjiang River Basin from 1426–2017 and analyzes their spatial and temporal variation characteristics. The res...

Extreme weather events, such as extreme cold events (ECEs), are occurring more frequently due to climate change and variability. The ECEs have severe impacts on people’s lives and the economy. In this study, we used observational data for the period 1978-2020 from three national meteorological stations and forty-nine automatic weather stations loca...

Much attention has been paid to extreme temperature changes since 1961 because of the absence of data in the early 20th century. Based on the sub-daily meteorological records prior to 1950 and modern daily meteorological records from 1951 to 2020, we established a daily maximum/minimum temperature series that was processed for data quality control,...

Changes in the thermal comfort condition of the living environment of human beings are one of the main concerns related to global warming. While previous studies largely focused on mean temperature and warm/cold extremes, changes in thermal comfort conditions (both comfort and discomfort conditions) have not been adequately revealed. Based on clima...

Extremes in sea surface temperature (SST) have the potential to threaten marine biodiversity, ecosystem functions, and regional services. Using the OISST v2 data, we analyzed the spatial and temporal variability of marine hot and cold events in the China Seas during 1982–2020. Results showed that in majority of the China Seas, frequency of Hot Days...

Using multisource sea ice fusion data, the spatiotemporal characteristics of sea ice cover were analyzed for the marginal seas of East Asia for the period 2005–2021. The results show that there were obvious differences in the beginning and end dates of the sea ice in the different sea areas. The northern Sea of Japan had the longest ice period, and...

Based on different reanalysis datasets, reconstructions of East Asia landfall tropical cyclones (TCs) were compared with observations. The 20th-century reanalysis version 3 dataset (20CRv3) received the most approval in this assessment. It performed better in terms of annual frequency. The fifth generation of atmospheric reanalysis dataset (ERA5) a...

Heatwaves describe prolonged periods of excessive heat. The increasing trend in heatwave frequency, duration, and magnitude in a warmer future has been extensively investigated. However, the vast majority of traditional studies on heatwaves consider only the role of air temperature, which is inadequate as a metric for human heat stress. While repor...

A marine heatwave (MHW) can significantly harm marine ecosystems and fisheries. Based on a remotely sensed sea surface temperature (SST) product, this study investigated MHWs behaviors in the South China Sea (SCS) throughout the warm season (May to September) from 1982 to 2020. The distributions of the three MHW indices used in this study showed si...

Previous studies largely focus on changes in mean climate state and climate extremes under a warmer climate, and little is known about changes in mild weather, which is a positive and pleasant condition and is highly related to human outdoor activities. Although changes in observed mild weather frequency over China and their drivers have been revea...

Instrumental data from the pre–Industrial Revolution period are important to ­understand climate change. In this paper, the observations made by the French missionary J. Amiot in present-day central Beijing during 1757–62 were processed and analyzed. The observations represent the earliest continuous dataset of meteorological records found in China...

Landfalling tropical cyclones (LTCs) is one of the most serious meteorological disasters in China due to the provided severe wind and heavy rainfall. Tropical cyclone–induced rainfall in China has been proved to decrease in recent decades. However, how landfalling tropical cyclone–induced extreme rainfall (LTCER) has changed across China, as well a...

Tropical cyclone (TC) translation distance, proportional to its duration and translation speed, basically determines the spatial extent of TC-impacted marine and terrestrial areas. Although a long-term slowdown of TCs has recently been reported, changes in translation distance of TCs over the western North Pacific (WNP) and their driving mechanisms...

Drought is a major natural disaster that has long-lasting effects on economic and social activities in northern China and has regional distinctions in duration, severity, and spatial extent. In this study, tree-ring chronologies and historical archives in the Yellow River Basin and its surrounding areas are collected to investigate the extreme drou...

The major droughts and floods in the Hanjiang River Basin, central China, have a significant impact on flood prevention and control in the middle reaches of the Yangtze River and water resources management in the areas of the South–North Water Diversion Middle Line Project. However, there is a lack of understanding of the multi-decadal to centennia...

South Asia is home to one of the fastest-growing populations in Asia, and human activities are leaving indelible marks on the land surface. Yet the likelihood of successive observed droughts in South Asia (SA) and its four subregions (R-1: semi-arid, R-2: arid, R-3: subtropical wet, and R-4: tropical wet and dry) remains poorly understood. Using th...

Urban ventilation planning (UVP) are critically important to sustainable and green urban development. However, the climatic-environmental effects and benefits of urban ventilation corridors have yet to be fully understood. In this study, high-resolution simulation tests were carried out for winter of 2018 and summer of 2019 using the weather resear...

Much attention has been given to the large-scale anthropogenic influence on extreme temperature changes. However, the possible effects of atmospheric factors and the role of the locally anthropogenic driver on the observed regional change in extreme temperatures have not been well understood. Datasets of the China Meteorological Administration (CMA...

In recent years, the change of extreme precipitation in Mainland China has received extensive attention, and related research has obtained a lot of results. However, the high-resolution precipitation data from the well-known datasets worldwide generally start around 1951 at present, lacking daily precipitation data in Mainland China in the early 20...

Climatic comfort, which refers to the comfort of the human body’s thermal sensations, is important for the human habitat. Although considerable efforts have been provided to examine changes in climatic comfort response to global warming from a partial perspective, the trajectory shift in past and future climatic comfort conditions in China mainland...

Studying the spatiotemporal variations of the urban heat island (UHI) effect and its cause is important towards understanding urban climate change, planning and green development, and disaster mitigation. In this paper, by using surface observations and reanalysis data with objective classification of synoptic weather patterns (SWPs), we analyze th...

Plain Language Summary Henan is one of the most populated provinces in China. Two catastrophic extreme precipitation events in July 2021 and August 1975 caused devastating catastrophes, such as flooding and urban waterlogging, which resulted in widespread impacts on agricultural production, human livelihood, and economic development. We used a clus...

This study investigates future changes in daily precipitation extremes and the involved physics over the global land monsoon (GM) region using climate models from phase 6 of the Coupled Model Intercomparison Project (CMIP6). The daily precipitation extreme is identified by the cutoff scale, measuring the extreme tail of the precipitation distributi...

Drought is a major natural disaster that has long-lasting effects on economic and social activities in northern China and has regional distinctions in duration, severity, and spatial extent. In this study, tree-ring chronologies and historical archives in the Yellow River Basin and its surrounding areas were collected to investigate the dynamic pro...

Decrease in light precipitation (LP) frequency has been reported in many regions. However, reason for the decrease remains poorly understood. Here, we quantify urbanization effect on LP (< 3.0 mm day ⁻¹ ) trend in China over the period 1960–2018. We show that urbanization has significantly affected the decreasing LP trend. The urbanization effect b...

Under global warming, projected changes in precipitation have shown an asymmetrical shift from light to heavy precipitation over China. However, the role of urbanization in this shift remains unknown. Here, we show that increases in total rainy‐season (May‐September) precipitation over the Yangtze River Delta (YRD) urban agglomeration of East China...

The aim of the study is to estimate the trend in extreme temperature events in northern part of the Korean Peninsula during 1960–2019, as well as to conduct a comparison with the analysis results in other representative regions. All trends are examined based on quality-controlled daily maximum and minimum temperature data from 37 weather stations....

This is a topic collection of Climatic Change journal. It includes 15 articles and an extended introduction by the editors of the collection and the lead authors of the articles. The ISBN is: 978-94-024-2156-9. The articles can be also accessed at: https://link.springer.com/collections/hehacjebcg. We hope that these papers will help increase our...

Marine heatwaves (MHWs) are becoming more frequent and intense in many regions around the world. However, the MHWs over China's marginal seas and associated physical drivers are largely unknown. During August 2016, the Yellow Sea experienced the most intense MHW on record since 1982. Here, we used a set of high-resolution satellite data and reanaly...

The spatial distribution and temporal variation of the Urban Heat Island Intensity (UHII) are analyzed. We use the hourly surface air temperature (SAT) data from the observational networks of automatic weather stations during September 2012−August 2014 and January 2016−December 2017 over four cities, Changchun, Beijing, Wuhan and Guangzhou, and a p...

This study used the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to examine the moisture sources and pathways associated with warm-season precipitation over the Sichuan Basin (SCB), southwestern China, with emphasis on the long-term mean state and interannual variability. Four groups of moisture pathways were identified o...

The reanalysis datasets(CRA40) have now been developed in China Meteorological Administration. we aim to compare the differences in surface air temperature (SAT) between observational that has been adjusted for urbanization bias and reanalysis data (NCEPV1, NCEPV2, ERA5, CFSR, MERRA, JRA55, 20CRV3 and CRA40) over mainland China during 1961–2015. Th...

This is an extended editors’ commentary on the topical collection “Historical and recent change in extreme climate over East Asia”, which collects a total of 15 papers related to the change and variability of extreme climate events in East Asia over the last few hundreds years. The extreme climate events are broadly classified into three categories...

Soil moisture is an important variable of the climate system and is used to measure dry–wet change in hydro-climate. The warming trend has slowed in China over the past 20 years since 1998, and how the soil moisture changes in this period deserves our attention. With North China as a research region, this study uses the Global Land Data Assimilatio...

Whether the urban heat island (UHI) is affected by air pollution in urban areas has attracted much attention. By analyzing the observation data of automatic weather stations and environmental monitoring stations in Beijing from 2016 to 2018, we found a seasonally dependent interlink of the UHI intensity (UHII) and PM2.5 concentration in urban areas...

Previous studies indicated that numbers of meso‐micro scale severe convective weather exhibited a significant decrease over China's mainland in the past decades. However, the possible mechanism of the decrease has not been well understood. This paper analyzes the changes in frequency of thunderstorm and lightning days using an updated data set of d...