Annual Precipitation In China Research Articles

Performance of regional climate model RegCM4 with a hydrostatic or non‐hydrostatic dynamic core at simulating precipitation extremes in China

AbstractIn this study, we investigated the performance of RegCM4 with a hydrostatic or non‐hydrostatic dynamic core and different land surface models at simulating the mean and extreme precipitation during 1991–1999 in China and the Beijing–Tianjin–Hebei urban agglomeration (JJJ) in northern China. The resolutions were 12 km with the whole of China included and 3 km nested over the JJJ region. The observed daily precipitation data comprised the CN05.1 data set from China Meteorological Administration. First, RegCM4 with a hydrostatic dynamic core forced by the Max Planck Institute Earth System Model (MPI‐ESM1.2‐HR) that participated in CMIP6 was used to simulate the east Asia area at a resolution of 12 km. Next, the RegCM4 results with 12 km resolution forced RegCM4 with a non‐hydrostatic dynamic core (RegCM4‐NH) to run over the JJJ region with a 3 km convection‐permitting scale through one‐way nesting. The results showed that RegCM4 with a hydrostatic and non‐hydrostatic core could obtain more detailed seasonal and annual precipitation in China and the JJJ region relative to MPI‐ESM1.2‐HR although their performance varied over different regions. RegCM4 with the community land surface model 4.5 (CLM4.5) generally performed better at simulating the mean and extreme precipitation over the four subregions of China than that with the Biosphere–Atmosphere Transfer Scheme because of more detailed descriptions of land surface processes of CLM4.5. RegCM4‐NH with convection‐permitting resolution improved the simulations of heavy precipitation extremes over JJJ compared with RegCM4 with a hydrostatic core and resolution of 12 km. In addition, RegCM4‐NH with CLM4.5 performed better at simulating heavy precipitation extremes over JJJ compared with all other simulations, with higher correlation coefficients and larger relative root mean squared errors.

Spatio-temporal variation of annual precipitation in China and its response to ENSO

Abstract The results showed that the precipitation in the study area was mainly in a downward trend before the mid-1930s, and then turned upward. In the 1950s, the precipitation generally showed a distribution of rising in the west and falling in the east, and this trend continued until the early 21st century. By 2007, except for the central part of the Continental Basin, the overall trend was mainly upward. In this study, 65 El Niño Southern Oscillation (ENSO) events were identified, including 24 El Niño events and 41 La Niña events. The precipitation was generally less when ENSO occurred. However, there were differences in the type and intensity of the event. For example, El Niño had a greater impact on precipitation than La Niña did, and extremely strong or strong El Niño/La Niña events had a more significant impact than moderate, weak, or extremely weak ones. The correlation between precipitation and El Niño or La Niña events had some similarities and differences. For example, precipitation was mainly negatively correlated with El Niño and La Niña at the same time, and both correlations were proportional to intensity, but the correlation between precipitation and El Niño was significantly stronger than that of La Niña.

Observed changes in temperature and precipitation over Asia, 1901-2020

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 stations in Asia since 1901 and systematic-bias-adjusted data from stations in China after 1950, we analyzed the long-term trends of surface air temperature (SAT) and precipitation in Asia and China from 1901-2020. The results showed that (1) in the 120 yr between 1901 and 2020, the annual mean SAT rose significantly at rates of 0.13 ± 0.01 and 0.14 ± 0.03°C decade-1 in Asia and China, respectively. The year 2020 in Asia may have been the warmest year since the beginning of the 20th century. (2) Since 1901, in both Asia and China, the annual mean minimum temperature increased more than twice as fast as the maximum temperature, and the diurnal temperature range (DTR) dropped significantly. (3) From 1901-2019, the annual precipitation anomaly percentage in Asia showed a significant increasing trend at an average rate of 0.52 ± 0.10% decade-1, and the increase was more obvious in high latitudes than in low to mid-latitudes. (4) Since 1901, there has been no significant change in annual precipitation in China, but there was a weak and non-significant decrease in the first half of the 20th century and a significant increase after the mid 20th century. The results presented in this paper can help us understand the spatio-temporal patterns and causes of climate change in the Asian continent and Chinese mainland.

Temporal and spatial variations of annual precipitation and meteorological drought in China during 1951-2018

Exploring the temporal and spatial variations of precipitation and drought is an important topic in hydro-logy. Based on the precipitation data of 619 meteorological stations in China from 1951 to 2018, we used anomaly percentage method and Morlet wavelet analysis to analyze the temporal and spatial variations of annual precipitation and drought. The results showed that annual precipitation in China showed a stepwise decreasing trend from southeast to northwest during the study period, and that the intensity of annual precipitation change was on the contrary. The precipitation near the boundary of the second and third steps showed a downward trend, and the abrupt change of precipitation occurred mainly in the 1960s and 1970s. The rest region was on the rise, with substantial changes in the 1990s. The main period of precipitation was short in the regions with temperate continental climate and temperate monsoon climate. From 1960s to 2010s, the area of arid land in China had decreased, while that of the semi-arid area and semi-humid area had increased gradually, especially in the recent decade. An aridity boundary was found between 30° N and 40° N, with drought frequency in its north being much more than the south. On the whole, the frequency and scope of drought events showed a decreasing trend and its interdecadal shift direction was from the central part of northwest China to the southern part of North China and then to the northern part of North China.

Quantitative response relationships between annual precipitation in China from 1951 to 2018 and its influencing factors

Abstract Continuous changes in the global climate have exacerbated the uneven spatial distribution of water resources. The quantitative response relationships between precipitation and its influencing factors are an important research topic. In this study, the responses of precipitation to its influencing factors were quantified by analysing the large-spatial-scale data such as the monthly precipitation data of 619 meteorological stations in China from 1951 to 2018, the CMIP6 data, and the AMO through empirical orthogonal function decomposition, partial redundancy analysis, and ensemble empirical mode decomposition. As shown by the results, the overall response relationships between precipitation in China and the AMO and MEI were relatively strong, and the PDO and AGG affected precipitation in western China. The precipitation in the area north of 25 °N had strong response relationships with the SR and AO. AP affected the precipitation in Northeast China, while WS affected the precipitation in North China and western China. RH affected the precipitation in the regions south of 25 °N. The response relationship between precipitation and CO2 was weakest. The total contribution rate of the influencing factors to the annual precipitation was higher in the west and lower in the east. In the regions west of 100 °E, the total contribution rate of the influencing factors to annual precipitation increased from south to north. In the regions east of 100 °E, the total contribution rate of the influencing factors to the annual precipitation decreased from north and south to the central area, AO and AP contributed little to the annual precipitation across China.

On the Stationarity of Annual Precipitation over China (1959–2018)

AbstractStationarity is an assumption that permeates training and practice in water-resource engineering. However, with global change, the validity of stationarity as well as uncertainty of nonstationarity in water-resource planning are being questioned; thus, it is critical to evaluate the stationarity of climate variables, especially precipitation. Based on the continuous observation data of precipitation from 1427 stations across China, 593 efficient grid cells (1° × 1°) are constructed, and the annual precipitation stationarities from 1959 to 2018 are analyzed. The evaluated autocorrelation stationarity indicates that 92.24%–96.12% of the grid cells for an autocorrelation coefficient of lag 1–8 years of precipitation are indistinguishable from 0 [90% confidence level (CL)]. The mean stationarity indicates that 97.47% of the grid cells have a stable mean for 30 years (90% CL); beyond the confidence limits, they are mainly located in the northwest of China, where annual precipitation is less, and the average exceeding range is ±3.78 mm. The long-term observation of annual precipitation in Beijing (1819–2018) and Shanghai (1879–2018) also yields autocorrelation and mean stationarities. There is no significant difference in the annual precipitations between the past 20 years (1999–2018) and the past 60 years (1959–2018) over China. Therefore, the annual precipitation in China exhibits a weak stationary behavior that is indistinguishable from the stationary stochastic process. The average variation in precipitation is ±9.55% between 30 successive years and 16.53% between 10 successive years. Therefore, it is valuable and feasible to utilize the historical data of annual precipitation as the basis of water-resources application.

Gradation of the significance level of trends in precipitation over China

AbstractHow to accurately detect and estimate the significance level of trends in hydroclimate time series is a challenge. Building on correlation analysis, we propose an approach for evaluating and grading the significance level of trend in a series, and apply it to evaluate the changes in annual precipitation in China. The approach involved first formulating the relationship between the correlation coefficient and trend's slope. Four correlation coefficient thresholds are then determined by considering the influence of significance levels and data length, and the significance of trends is graded as five levels: no, weak, moderate, strong and dramatic. A larger correlation coefficient reflects a larger slope of trend and its higher significance level. Results of Monte-Carlo experiments indicated that the correlation coefficient-based approach not only reflects the magnitude of a trend, but also considers the influence of dispersion degree and mean value of the original series. Compared with the Mann–Kendall test used commonly, the proposed approach gave more accurate and specific gradation of the significance level of trends in annual precipitation over China. We find that the precipitation trends over China are not uniform, and the effects of global climate change on precipitation are not strong and limited to some regions.

Impacts of global warming of 1.5 °C and 2.0 °C on precipitation patterns in China by regional climate model (COSMO-CLM)

Regional precipitation patterns may change in a warmer climate, thereby increasing flood and drought risks. In this paper, annual, annual maximum, intense, heavy, moderate, light, and trace precipitation are employed as indicators to assess changes in precipitation patterns under two scenarios in which the global mean temperature increases by 1.5°C and 2.0°C relative to pre-industrial levels using the regional climate model COSMO-CLM (CCLM). The results show that annual precipitation in China will be approximately 2.5% higher under 1.5°C warming relative to the present-day baseline (1980–2009), although it will decrease by approximately 4.0% under an additional 0.5°C increase in global mean temperature. This trend is spatially consistent for regions with annual precipitation of 400–800mm, which has experienced a drying trend during the past half century; thus, limiting global warming to 1.5°C may mitigate these drying conditions. The annual maximum precipitation continues to increase from present day levels to the 2.0°C warming scenario. Relative to the baseline period, the frequency of trace and light precipitation days exhibits a negative trend, while that of moderate, heavy, and intense precipitation days has a positive trend under the 1.5°C warming scenario. For the 2.0°C warming world, the frequency of days is projected to decrease for all precipitation categories, although the intensity of intense precipitation increases. Spatially, a decrease in the number of precipitation days is expected to continue in central and northern China, where a drying trend has persisted over the past half century. Southeastern China, which already suffers greatly from flooding, is expected to face more heavy and intense precipitation with an additional 0.5°C increase in global mean temperature. Meanwhile, the intensity of intense precipitation is expected to increase in northern China, and the contribution of light and moderate precipitation to the annual precipitation is expected to decrease in southeastern China. Therefore, flood risk in northern China and drought risk in southern China should draw more attention for a global air temperature increase from 1.5°C to 2.0°C.

Global calibration of a novel, branched GDGT-based soil pH proxy

Recently, 6-methyl branched glycerol dialkyl glycerol tetraethers (brGDGTs) were separated from 5-methyl brGDGTs, which are used in brGDGT-based proxies. Here we analyzed brGDGTs in 27 soil samples along the 400mm isoline of mean annual precipitation in China by using tandem 2D liquid chromatography. The fractional abundance of 6-methyl brGDGTs showed a positive correlation with soil pH, while that of 5-methyl brGDGTs decreased with increasing soil pH. The abundance ratio of 6-/5-methyl brGDGTs, namely the isomerization of branched tetraethers (IBT), was calculated. The correlation of IBT with pH (pH=6.33−1.28×IBT; R2 0.89; root mean squared error, RMSE, 0.24) was much stronger than that of the traditionally used cyclization index of branched tetraethers (CBT) with pH (R2 0.52; RMSE 0.49) and comparable with that of CBT′ with pH (R2 0.88; RMSE 0.25). Compiling all available data from 319 soil samples resulted in a global calibration: pH=6.53−1.55×IBT (R2 0.72; RMSE 0.65), which has a better correlation than the CBT5ME-pH proxy (R2 0.63; RMSE 0.78), but a weaker correlation than the CBT′-pH proxy (R2 0.85; RMSE 0.52). Our result suggests that the IBT is a promising indicator for soil pH, particularly in cases when some compounds in the CBT′ index cannot be determined.

Sensitivity of precipitation over China to different cumulus parameterization schemes in RegCM4

The effect of different cumulus parameterization schemes (CPSs) on precipitation over China is investigated by using the International Centre for Theoretical Physics (ICTP) Regional Climate Model version 4.3 (RegCM-4.3) coupled with the land surface model BATS1e (Biosphere-Atmosphere Transfer Scheme version 1e). The ERA-interim data are utilized to drive a group of simulations over a 31-yr period from September 1982 to December 2012. Two typically sensitive regions, i.e., the eastern Tibetan Plateau (TP; 29°–38°N, 90°–100°E) and eastern China (EC; 26°–32°N, 110°–120°E), are focused on. The results show that all the CPSs have well reproduced the spatial distribution of annual precipitation in China. The simulation with the Emanuel scheme shows an overall overestimation of precipitation in China, different from the other three CPSs which only overestimate over northern and northwestern China but underestimate over southern China. Seasonally, the Tiedtke scheme shows the smallest overestimation in winter and summer, and the best simulation of the annual variance of precipitation. Interannual variations of precipitation among the four CPSs are generally simulated better in summer than in winter, and better for entire China than in the subregions of TP and EC. The precipitation trend is simulated better over EC than over TP, and better in summer than in winter. An overestimate (underestimate) of the East Asian summer monsoon index (EASMI) exists in the simulations with the Grell and the Emanuel (the Kuo and the Tiedtke) schemes. The smallest EASMI bias in the Tiedtke simulation could explain its small precipitation bias. A negative correlation between the EASMI and summer precipitation over the middle and lower reaches of Yangtze River is found in the Grell and the Emanuel simulations, but was missed by the simulations using the Kuo and the Tiedtke schemes.

Projected change in extreme rainfall events in China by the end of the 21st century using CMIP5 models

Projection of future climate changes and their regional impact is critical for long-term planning at the national and regional levels aimed at adaptation and mitigation. This study assesses the future changes in precipitation in China and the associated atmospheric circulation patterns using the Couple Model Intercomparison Project 5 Phase (CMIP5) simulations under the RCP4.5 and RCP8.5 scenarios. The results consistently indicate that the annual precipitation in China is projected to significantly increase at the end of the 21st century compared to the present-day levels. The number of days and the intensity of medium rain, large rain and heavy rain are obviously increased, while the number of trace rain days is projected to decrease over the entire area of China. Further analysis indicates that the significant increase of annual precipitation in Northwest China is primarily due to the increase of light rain and the increases in North and Northeast China are primarily due to the increase of medium rain. In the region of southern China, the increases of large rain and heavy rain play an important role in the increase of annual precipitation, while light rain events play a negative role. Analysis of the changes in atmospheric circulation indicates that the East Asian summer monsoon circulation is projected to be considerably stronger, and the local atmospheric stratification is projected to be more unstable, all of which provide a background benefit for the increase of precipitation and extreme rainfall events in China under global warming scenarios.

Development of China homogenized monthly precipitation dataset during 1900–2009

Based on the collection and processing of the China national-wide monthly station observational precipitation data in 1900–2009, the data series for each station has been tested for their homogeneity with the Standard Normalized Homogeneity Test (SNHT) method and the inhomogeneous parts of the series are adjusted or corrected. Based on the data, the precipitation anomalies during 1900–2009 and the climatology normals during 1971–2000 have been transformed into the grid boxes at 5°×5° and 2°×2° resolutions respectively. And two grid form datasets are constructed by combining the normal and anomalies. After that, the missing values for the 5°×5° grid dataset are interpolated by Empirical Orthogonal Function (EOF) techniques. With the datasets of different resolutions, the precipitation change series during 1900–2009 over Mainland China are built, and the annual and seasonal precipitation trends for the recent 110 years are analyzed. The result indicates that the annual precipitation shows a slight dryer trend during the past 110 years, notwithstanding lack of statistical confidence. It is worth noting that after the interpolation of the missing values, the annual precipitation amounts in the early 1900s become less, which increases the changing trend of the annual precipitation in China for the whole 110 years slightly (from −7.48 mm/100a to −6.48 mm/100a).

Trend of climate variability in China during the past decades

Trends in precipitation and mean air temperature in China are estimated, and trend analysis on statistical moments of residuals is further used to investigate climate variability at different timescales. Trends of statistical moments for residuals (i.e. detrended series of climate records) are estimated by using least-square method and Mann–Kendall test. Results show that upward trend is detected in annual mean air temperature but no linear trend for annual precipitation in China. Weak trend is found for variability of precipitation while no trend is found for that of air temperature for China as a whole. But some regional features of climate variability are observed. It is found that the northwest of China shows a significant increasing for precipitation variability, which is consistent with previous work, especially for monthly precipitation. No change is detected in monthly mean air temperature for all stations, while small decreasing and increasing trends are detected for variability of annual mean air temperature in northeast of China and southwest of China, respectively.

A Bias-Corrected Precipitation Climatology for China

Abstract This paper presents the results of bias corrections of Chinese standard precipitation gauge (CSPG) measurements for wind-induced undercatch, a trace amount of precipitation, and wetting loss. Long-term daily data of precipitation, temperature, and wind speed during 1951–98 at 710 meteorological stations in China were used for this analysis. It is found that wind-induced gauge undercatch is the greatest error in most regions, and wetting loss and a trace amount of precipitation are important in the low-precipitation regions in northwest China. Monthly correction factors ratio of corrected amount to measured amount of precipitation differ by location and by type of precipitation. Considerable interannual variation of the corrections exists in China due to the fluctuations of wind speed and frequency of precipitation. More importantly, annual precipitation has been increased by 8 to 740 mm with an overall mean of 130 mm at the 710 stations over China because of the bias corrections for the study period. This corresponds to 6%–62% increases (overall mean of 19% at the 710 stations over China) in gauge-measured yearly total precipitation over China. This important finding clearly suggests that annual precipitation in China is much higher than previously reported. The results of this study will be useful to hydrological and climatic studies in China.