Applicability Assessment of GPCC and CRU Precipitation Products in China during 1901 to 2013
-
摘要: 利用1901~2013年中国大陆地区的气象台站实测降水资料,对东英吉利(East Anglia)大学气候研究中心(Climatic Research Unit,CRU)和全球降水气候中心(Global Precipitation Climatology Centre,GPCC)的降水资料分别从季节、年际和年代际尺度上进行了评估。结果表明:1961~2013年CRU与GPCC降水资料均能较准确地描述中国大陆地区的降水特征,且在东部较西部地区、夏季较冬季与站点实测降水情况更为一致。将中国大陆划分为不同区域并在其季节、年际和年代际时间尺度上通过比较降水偏差绝对值的百分比、均方根误差和相关系数等统计量后发现:CRU在青藏高原和其它较大的山脉附近与站点实测降水的差别较大,且年均降水趋势在西北一带的阿尔金山脉、黄土高原、东南地区和长江下游地区,比实测降水的年均趋势小、甚至出现趋势相反的情况。此外,CRU降水的年代际变化趋势也偏小。而GPCC数据不论是降水量还是降水趋势都更接近实际情况。在1901~1961年,通过与65个长期气象观测站点的降水时间序列比较发现,CRU在110°E以西地区与站点观测的降水资料间的差别较大,而GPCC与站点观测资料的吻合较好。最后,利用1961~2013年两套降水资料和站点实测资料分别计算了标准化降水指数(SPI),简单分析了中国大陆地区的干旱变化,发现GPCC对旱涝的时空变化特征的描述比CRU更接近站点实际观测;并且CRU也没有反映出1997年夏季中国地区出现的严重干旱情况,而GPCC较为准确地反映出了这一干旱事件特征。因此,本文的研究结果认为,就中国大陆地区长时期降水资料而言,GPCC的适用性优于CRU。Abstract: Two gridded precipitation datasets from the Climatic Research Unit (CRU) and the Global Precipitation Climatology Centre (GPCC) are evaluated using the station-observed precipitation over China for the period of 1901-2013 at the seasonal, annual, and interdecadal time scales, respectively. The main results are:Firstly, for the period of 1961-2013, both CRU and GPCC products are able to describe the temporal-spatial variation of precipitation in China, and both show a better performance in eastern China than in western China and in summer than in winter. On the annual and seasonal time scales, comprehensive comparisons are also performed through analyzing the percentages of absolute deviation, the root-mean-square errors, and the correlation coefficients between two products with the station observations. It is found that the CRU data shows large biases in the Tibetan Plateau and some other areas of large mountains, and the annual precipitation trend derived from CRU data is also smaller than that from station observations over areas such as the Altun Shan Mai, the Loess Plateau, southeastern China, and the lower reaches of the Yangtze River basin, while GPCC data is relatively more consistent with the station observations in both precipitation amount and trend. Secondly, for the period of 1901-1961, in-situ observed precipitation at 65 stations are used to compare with CRU and GPCC products. It is found that CRU shows large deficiencies to the west of 110°E in the arid and simi-arid regions in China, while GPCC agrees well with observations. Finally, the two gridded datasets and station observations for the period of 1961-2013 are used to compute the standardized precipitation index (SPI), which is then used to describe the degree of aridity in China. The results show that the GPCC is closer to the observations than CRU in terms of the dry and wet events variations in China. For instance, GPCC can capture the severe drought in the summer of 1997, but CRU cannot. In summary, this study suggests that GPCC is a better choices compared to CRU for studying the long-term precipitation trend in China.
-
图 1 长期仪器记录的气候数据库中65个气象台站的分布和地形高度(单位:m)。黑线矩形框将全国分为7个区域:西北地区(NW:35.75°N~49.25°N,73.75°E~108.75°E)、西南地区(SW:21.25°N~35.75°N,97.75°E~108.75°E)、东北地区(NE:42.25°N~53.75°N,108.75°E~135.25°E)、华北地区(NC:35.25°N~42.25°N,108.75°E~128.75°E)、长江流域(YZ:27.75°N~35.25°N,108.75°E~123.25°E)、华南地区(SE:18.25°N~27.75°N,108.75°E~120.25°E)、青藏高原地区(TIBET:26.75°N~35.75°N,77.25 °E~97.75°E)
Figure 1. Locations of 65 rain gauge stations for long-term observations in the climatic database of China and their elevations (m). The black boxes indicate the seven subregions of China: Northwest China (NW: 35.75°N-49.25°N, 73.75°E-108.75°E), Southwest China (SW: 21.25°N-35.75°N, 97.75°E-108.75°E), Northeast China (NE: 42.25°N-53.75°N, 108.75°E-135.25°E), North China (NC: 35.25°N-42.25°N, 108.75°E-128.75°E), the Yangtze River valley (YZ: 27.75°N-35.25°N, 108.75°E-123.25°E), Southeast China (SE: 18.25°N-27.75°N, 108.75°E-120.25°E), and Qinghai-Tibet Plateau (TIBET: 26.75°N-35.75°N, 77.25°E-97.75°E)
图 2 多年平均(1961~2013年)的(a、c、e)CRU与CN05.1和(b、d、f)CPCC与CN05.1降水量的偏差(单位:mm/d,黑点表示通过99%的显著性检验):(a、b)年均;(c、d)夏季平均;(e、f)冬季平均
Figure 2. Spatial distributions of long-term (1961-2013) mean precipitation differences (mm/d) (a, c, e) between CRU (Climatic Research Unit) and CN05.1 data and (b, d, f) between GPCC (Global Precipitation Climatology Centre) and CN05.1 data in China: (a, b) Annual; (c, d) summer; (e, f) winter. The black dotted areas indicate the differences pass the 99% confidence level
图 3 CN05.1(左)、CRU(中)和GPCC(右)三套降水数据在1961~2013年线性趋势(单位:mm/a,黑点表示通过95%置信检验):(a、b、c)年均降水;(d、e、f)夏季平均降水;(g、h、i)冬季平均降水
Figure 3. Linear trends of annual mean precipitation (mm/a) during 1961-2013 from CN05.1 (left colum), CRU (middle column), and GPCC (right column) data: (a, b, c) Annual; (d, e, f) summer; (g, h, i) winter. The black dots indicate the trends pass the 95% confidence level test
图 4 1961~2013年CN05.1、CRU、GPCC三套数据年降水量在不同地区和不同年代的线性趋势(单位:mm/a):(a)1961~1970年;(b)1971~1980年;(c)1981~1990年;(d)1991~2000年;(e)2001~2013年
Figure 4. Annual precipitation trends (mm/a) from CN05.1, CRU, and GPCC data over different regions in each decade for 1961-2013: (a) 1961-1970; (b) 1971-1980; (c) 1981-1990; (d) 1991-2000; (e) 2001-2013
图 6 华北地区5个站点年均降水量距平(单位:mm/d)的时间序列:(a)呼和浩特(13号站);(b)榆林(15号站);(c)太原(16号站);(d)沈阳(19号站);(e)北京(20号站)。图的左上角标明三类降水资料的多年年均降水量
Figure 6. Time series of annual mean precipitation anomaly (mm/d) at five stations in Northeast China: (a) Huhehaote station (No.13); (b) Yulin station (No.15); (c) Taiyuan station (No.16); (d) Shenyang station (No.19); (e) Beijing station (No.20). The long term annual mean precipitation derived from the three datasets are also shown in the upper left cornor of each panel
图 7 1961~2013年(时间尺度为3月)(a)CN05.1月平均降水计算的SPI的线性趋势分布以及(b)CRU计算的SPI线性趋势、(c)GPCC计算的SPI线性趋势分别与CN05.1的计算的SPI线性趋势的偏差的空间分布
Figure 7. (a) Linear trends of SPI (Standardized Precipitation Index) at 3-month time scale in China from 1961 to 2013 based on CN05.1 data, and differences in the SPI trends between (b) CRU and CN05.1 data, (c) GPCC and CN05.1 data
表 1 区域加权平均的各统计量:CN05.1的年均降水量、CN05.1分别与CRU和GPCC的降水偏差、降水偏差绝对值的百分比、均方根误差和相关系数
Table 1. Statistics of area-weighted averages: CN05.1 annual precipitation, precipitation deviations, percentages of absolute deviation, root-mean-square errors and correlation coefficients between CN05.1 and the two products of CRU and GPCC
CN05.1年降水量/mm d-1 与CN05.1的降水偏差/ mm d-1 与CN05.1的降水偏差绝对值的百分比 与CN05.1的均方根误差/ mm d-1 与CN05.1的相关系数 CRU GPC CRU GPC CRU GPC CRU GPC 西北地区 0.48 -0.08 -0.12 40.34% 31.89% 0.18 0.15 0.68 0.80 西南地区 2.74 -0.23 -0.12 15.15% 11.01% 0.45 0.33 0.70 0.87 东北地区 1.28 -0.04 -0.06 11.28% 9.67% 0.18 0.14 0.79 0.88 华北地区 1.52 -0.06 -0.03 11.99% 8.72% 0.22 0.16 0.82 0.92 长江流域 3.22 -0.14 -0.03 9.53% 6.61% 0.39 0.26 0.82 0.94 华南地区 4.55 -0.07 -0.13 8.57% 6.86% 0.50 0.37 0.85 0.94 青藏高原地区 1.07 0.29 0.24 67.79% 59.97% 0.65 0.61 0.55 0.62 全国 1.72 -0.04 -0.04 28.84% 23.28% 0.35 0.28 0.72 0.83 表 2 CN05.1、CRU、GPCC三套降水数据的区域面积加权平均的年均降水线性回归系数
Table 2. The area-weighted average of the annual precipitation's linear regression coefficients from CN05.1, CRU, and GPCC data
区域面积加权平均的年均降水线性回归系数 CN05.1 CRU GPCC 西北地区 0.52 0.38 0.57 西南地区 -0.99 -0.71 -0.80 东北地区 0.25* 0.26* 0.24* 华北地区 -0.22* -0.50 -0.66 长江流域 0.60* 0.41* 0.40* 华南地区 1.71 1.20 0.97* 青藏高原地区 0.71 0.66 0.58 全国 0.30 0.22 0.22 *表示通过95%的显著性检验 -
[1] 白虎志, 谢金南, 王宝灵, 等. 1999. 1997年甘肃省特大干旱事件的诊断分析[J].高原气象, 18 (1): 55-62. doi: 10.3321/j.issn:1000-0534.1999.01.007Bai Zhihu, Xie Jinnan, Wang Baoling, et al. 1999. Diagnosis analysis of serious drought event of 1997 in Gansu [J]. Plateau Meteorology, 18 (1): 55-62, doi: 10.3321/j.issn:1000-0534.1999.01.007. [2] Becker A, Finger P, Meyer-Christoffer A, et al. 2013. A description of the global land-surface precipitation data products of the Global Precipitation Climatology Centre with sample applications including centennial (trend) analysis from 1901-present [J]. Earth System Science Data Discussions, 5(2): 921-998, doi: 10.5194/essdd-5-921-2012. [3] 蔡榕硕, 谭红建, 黄荣辉. 2012.中国东部夏季降水年际变化与东中国海及邻近海域海温异常的关系[J].大气科学, 36 (1): 35-46. doi: 10.3878/j.issn.1006-9895.2012.01.04Cai Rongshuo, Tan Hongjian, Huang Ronghui. 2012. The relationship between interannual variations of summer precipitation in eastern China and the SST anomalies in the East China Sea and its adjacent seas [J]. Chinese Journal of Atmospheric Sciences (in Chinese), 36 (1): 35-46, doi: 10.3878/j.issn.1006-9895.2012.01.04. [4] 高荣, 董文杰, 韦志刚. 2008.西北干旱区感热异常对中国夏季降水影响的模拟[J].高原气象, 27 (2): 320-324. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200802011.htmGao Rong, Dong Wenjie, Wei Zhigang. 2008. Numerical simulation of the impact of abnormity of sensible heat flux in northwest arid zone on precipitation in China [J]. Plateau Meteorology (in Chinese), 27 (2): 320-324. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200802011.htm [5] 韩振宇, 周天军. 2012. APHRODITE高分辨率逐日降水资料在中国大陆地区的适用性[J].大气科学, 36 (2): 361-373. Han Zhenyu, Zhou Tianjun. 2012. Assessing the quality of APHRODITE high-resolution daily precipitation dataset over contiguous China [J]. Chinese Journal of Atmospheric Sciences (in Chinese), 36 (2): 361-373, doi: 10.3878/j.issn. 1006-9895.2011.11043. [6] Harris I, Jones P D, Osborn T J, et al. 2014. Updated high-resolution grids of monthly climatic observations-the CRU TS3.10 dataset [J]. International Journal of Climatology, 34 (3): 623-642, doi: 10.1002/joc.3711. [7] IPCC. 2013. Climate Change 2013: The Scientific Basis [M]. Stocker T F, Qin D, Plattner G-K, et al., Eds. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press, 44. [8] 金炜昕, 李维京, 孙丞虎, 等. 2015.夏季中国中东部不同历时降水时空分布特征[J].气候与环境研究, 20 (4): 465-476. doi: 10.3878/j.issn.1006-9585.2015.14268Jin Weixin, Li Weijing, Sun Chenghu, et al. 2015. Spatiotemporal characteristics of summer precipitation with different durations in central East China [J]. Climatic and Environmental Research (in Chinese), 20 (4): 465-476, doi: 10.3878/j.issn.1006-9585.2015.14268. [9] 姜贵祥, 孙旭光. 2016.格点降水资料在中国东部夏季降水变率研究中的适用性[J].气象科学, 36 (4): 448-456. doi: 10.3969/2015jms.0021Jiang Guixiang, Sun Xuguang. 2016. Application of grid precipitation datasets in summer precipitation variability over East China [J]. Journal of the Meteorological Sciences (in Chinese), 36 (4): 448-456, doi: 10.3969/2015jms.0021. [10] Kaiser D P. 1991. Two Long-Term Instrumental Climatic Data bases of the People's Republic of China [J]. Environmental Policy Collection, doi: 10.3334/CDIAC/cli.ndp039. [11] 李聪, 肖子牛, 张晓玲. 2012.近60年中国不同区域降水的气候变化特征[J].气象, 38 (4): 419-424. doi: 10.7519/j.issn.1000-0526.2012.4.005Li Cong, Xiao Ziniu, Zhang Xiaoling. 2012. Climatic characteristics of precipitation in various regions of China for the past 60 years [J]. Meteorological Monthly, 38 (4): 419-424, doi: 10.7519/j.issn.1000-0526.2012.4.005. [12] 李崇银, 朱锦红, 孙照渤. 2002.年代际气候变化研究[J].气候与环境研究, 7 (2): 209-219. doi: 10.3969/j.issn.1006-9585.2002.02.008Li Congyin, Zhu Jinhong, Sun Zhaobo. 2002. The study interdecadel climate variation[J]. Climatic and Environmental Research, 7 (2): 209-219, doi: 10.3969/j.issn.1006-9585.2002.02.008. [13] 吕俊梅, 琚建华, 江剑民. 2009.近一百年中国东部区域降水的年代际跃变[J].大气科学, 33 (3): 524-536. doi: 10.3878/j.issn.1006-9895.2009.03.10Lü Junmei, Ju Jianhua, Jiang Jianmin. 2009. Interdecadal regime shifts of regional precipitation over eastern China during the last 100 years [J]. Chinese Journal of Atmospheric Sciences (in Chinese), 33 (3): 524-536, doi: 10.3878/j.issn. 1006-9895.2009.03.10. [14] 吕俊梅, 祝从文, 琚建华, 等. 2014.近百年中国东部夏季降水年代际变化特征及其原因[J].大气科学, 38 (4): 782-794. doi: 10.3878/j.issn.1006-9895.1401.13227Lü Junmei, Zhu Congwen, Ju Jianhua, et al. 2014. Interdecadal variability in summer precipitation over East China during the past 100 years and its possible causes [J]. Chinese Journal of Atmospheric Sciences (in Chinese), 38 (4):782-794, doi: 10.3878/j.issn.1006-9895.1401.13227. [15] 吕少宁, 文军, 刘蓉. 2011.中国大陆地区不同降水资料的适用性及其应用潜力[J].高原气象, 30 (3): 628-640. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX201103010.htmLü Shaoning, Wen Jun, Liu Rong. 2011. Applicability and potential of the different precipitation data in mainland China [J]. Plateau Meteorology, 30 (3): 628-640. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX201103010.htm [16] 马柱国. 2007.华北干旱化趋势及转折性变化与太平洋年代际振荡的关系[J].科学通报, 52 (10): 1199-1206. doi: 10.3321/j.issn:0023-074X.2007.10.018Ma Zhuguo. 2007. The interdecadal trend and shift of dry/wet over the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO) [J]. Chinese Science Bulletin, 52 (15): 2130-2139, doi: 10.3321/j.issn:0023-074X.2007.10.018. [17] Ma L J, Zhang T J, Frauenfeld O W, et al. 2009. Evaluation of precipitation from the ERA-40, NCEP-1, and NCEP-2 reanalyses and CMAP-1, CMAP-2, and GPCP-2 with ground-based measurements in China [J]. J.Geophys. Res.:, 114 (D9): D09105, doi: 10.1029/2008JD011178. [18] Ma S M, Zhou T J, Dai A G, et al. 2015. Observed changes in the distributions of daily precipitation frequency and amount over China from 1960 to 2013 [J]. J. Climate, 28: 6960-6978, doi: 10.1175/JCLI-D-15-0011.1. [19] McKee T B, Doesken N J, Kleist J. 1995. Drought monitoring with multiple time scales [C]//Proceedings of the Ninth Conference on Applied Climatology. Dallas TX: American Meteorological Society, 233-236. [20] New M, Hulme M, Jones P. 2000. Representing twentieth-century space-time climate variability. Part Ⅱ: Development of 1901-96 monthly grids of terrestrial surface climate [J]. J. Climate, 13: 2217-2238, doi:10.1175/1520-0442(2000)013<2217:RTCSTC>2.0.CO;2. [21] 施雅风, 沈永平, 胡汝骥. 2002.西北气候由暖干向暖湿转型的信号、影响和前景初步探讨[J].冰川冻土, 24 (3): 219-226. doi: 10.3969/j.issn.1000-0240.2002.03.001Shi Yafeng, Shen Yongping, Hu Ruji. 2002. Preliminary study on signal, impact and foreground of climatic shift from warm-dry to warm-humid in Northwest China [J]. Journal of Glaciology and Geocryology (in Chinese), 24 (3):219-226, doi: 10.3969/j.issn.1000-0240.2002.03.001. [22] 施雅风, 沈永平, 李栋梁, 等. 2003.中国西北气候由暖干向暖湿转型的特征和趋势探讨[J].第四纪研究, 23 (2): 152-164. doi: 10.3321/j.issn:1001-7410.2003.02.005Shi Yafeng, Shen Yongping, Li Dongliang, et al. 2003. Disscussion on the present climate change from warm-dry to warm-wet in Northwest China [J]. Quaternary Sciences (in Chinese), 23 (2): 152-164, doi: 10.3321/j.issn:1001-7410. 2003.02.005. [23] Schneider U, Becker A, Finger P, et al. 2014. GPCC's new land surface precipitation climatology based on quality-controlled in situ data and its role in quantifying the global water cycle [J]. Theor. Appl. Climatol., 115:15-40, doi: 10.1007/s00704-013-0860-x. [24] Sun Q H, Miao C Y, Duan Q Y, et al. 2014. Would the 'real' observed dataset stand up? A critical examination of eight observed gridded climate datasets for China [J]. Environmental Research Letters, 9(1): 015001, doi: 10.1088/1748-9326/9/1/015001. [25] Taylor K E. 2001. Summarizing multiple aspects of model performance in a single diagram [J]. J. Geophys. Res., 106 (D7): 7183-7192, doi: 10.1029/2000JD900719. [26] Trenberth K E, Dai A G, Rasmussen R M, et al. 2003. The changing character of precipitation [J]. Bulle. Amer. Meteor. Soc., 84: 1205-1217, doi: 10.1175/BAMS-84-9-1205. [27] Trenberth K E, Dai A G, Van Der Schrier G, et al. 2014. Global warming and changes in drought[J]. Nature Climate Change, 4: 17-22, doi: 10.1038/nclimate2067. [28] 王芬, 曹杰, 李腹广, 等. 2013.多套格点降水资料在云南及周边地区的对比[J].应用气象学报, 24 (4): 472-483. doi: 10.3969/j.issn.1001-7313.2013.04.010Wang Fen, Cao Jie, Li Fuguang, et al. 2013. Datasets and rain gauge precipitation over Yunnan and the surrounding areas [J]. Journal of Applied Meteorological Science(in Chinese), 24 (4): 472-483, doi: 10.3969/j.issn.1001-7313.2013.04.010. [29] 王英, 曹明奎, 陶波, 等. 2006.全球气候变化背景下中国降水量空间格局的变化特征[J].地理研究, 25 (6): 1031-1040. doi: 10.3321/j.issn:1000-0585.2006.06.010Wang Ying, Cao Mingkui, Tao Bo, et al. 2006. The characteristics of spatio-temporal patterns in precipitation in China under the background of global climate change [J]. Geographical Research (in Chinese), 25 (6): 1031-1040, doi: 10.3321/j.issn:1000-0585.2006.06.010. [30] 王绍武, 龚道溢, 叶瑾琳, 等. 2000. 1880年以来中国东部四季降水量序列及其变率[J].地理学报, 55 (3): 281-293. doi: 10.3321/j.issn:0375-5444.2000.03.004Wang Shaowu, Gong Daoyi, Ye Jinlin, et al. 2000. Seasonal precipitation series of eastern China since 1880 and the variability [J]. Acta Geographica Sinica (in Chinese), 55 (3): 281-293, doi: 10.3321/j.issn:0375-5444.2000.03.004. [31] 吴福婷, 符淙斌. 2013.全球变暖背景下不同空间尺度降水谱的变化[J].科学通报, 58 (8): 664-673. doi: 10.1007/s11434-013-5699-0Wu Futing, Fu Congbin. 2013. Change of precipitation intensity spectra at different spatial scales under warming conditions [J]. Chinese Science Bulletin (in Chinese), 58 (12): 1385-1394, doi: 10.1007/s11434-013-5699-0. [32] 吴佳, 高学杰. 2013.一套格点化的中国区域逐日观测资料及与其它资料的对比[J].地球物理学报, 56 (4): 1102-1111. doi: 10.6038/cjg20130406Wu Jia, Gao Xuejie. 2013. A gridded daily observation dataset over China region and comparison with the other datasets [J]. Chinese Journal of Geophysics (in Chinese), 56 (4): 1102-1111, doi: 10.6038/cjg20130406. [33] 吴娴, 黄伟, 陈发虎. 2014. 1951-2012年中国大陆0.025°×0.025°高分辨率月气温和降水量格点数据集的建立及其初步应用[J].兰州大学学报(自然科学版), 50 (2): 213-220. http://www.cnki.com.cn/Article/CJFDTOTAL-LDZK201402011.htmWu Xian, Huang Wei, Chen Fahu. 2014. Construction and application of monthly air temperature and precipitation gridded datasets with high resolution (0.025°×0.025°) over China during 1951-2012 [J]. Journal of Lanzhou University (Natural Sciences), 50 (2): 213-220. http://www.cnki.com.cn/Article/CJFDTOTAL-LDZK201402011.htm [34] Wang H J. 2001. The weakening of the Asian monsoon circulation after the end of 1970's [J]. Advances in Atmospheric Sciences, 18: 376-386, doi: 10.1007/BF02919316. [35] 叶柏生, 李翀, 杨大庆, 等. 2004.我国过去50 a来降水变化趋势及其对水资源的影响(Ⅰ):年系列[J].冰川冻土, 26 (5): 587-594. doi: 10.3969/j.issn.1000-0240.2004.05.013Ye Baisheng, Li Chong, Yang Daqing, et al. 2004. Variation trend of precipitation and its impact on water resources in China during last 50 Years (Ⅰ): annual variation [J]. Journal of Glaciology and Geocryology (in Chinese), 26 (5):587-594, doi: 10.3969/j.issn.1000-0240.2004.05.013. [36] 虞海燕, 刘树华, 赵娜, 等. 2011. 1951-2009年中国不同区域气温和降水量变化特征[J].气象与环境学报, 27 (4): 1-11. doi: 10.3969/j.issn.1673-503X.2011.04.001Yu Haiyan, Liu Shuhua, Zhao Na, et al. 2011. Characteristics of air temperature and precipitation in different regions of China from 1951 to 2009 [J]. Journal of Meteorology and Environment (in Chinese), 27 (4): 1-11, doi: 10.3969/j.issn.1673-503X.2011.04.001. [37] Yatagai A, Arakawa O, Kamiguchi K, et al. 2009. A 44-year daily gridded precipitation dataset for Asia based on a dense network of rain gauges[J]. SOLA, 5 (1): 137-140, doi: 10.2151/sola.2009-035. [38] 赵从兰, 刘厚赞, 谭志华. 1998. 1997年夏季华北特大干旱及其成因[J].大气科学学报, 21 (3): 440-445. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX803.019.htmZhao Conglan, Liu Houzan, Tan Zhihua. 1998. Exceptional summer drought in northern china in 1997 and its contributing factors [J]. Transactions of Atmospheric Sciences, 21 (3):440-445. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX803.019.htm [39] 张杰, 李栋梁, 王文. 2008.夏季风期间青藏高原地形对降水的影响[J].地理科学, 28 (2): 235-240. doi: 10.3969/j.issn.1000-0690.2008.02.019Zhang Jie, Li Dongliang, Wang Wen. 2008. Influence of terrain on precipitation in Qinghai-Tibet Plateau during summer monsoon [J]. Scientia Geographica Sinica (in Chinese), 28 (2):235-240, doi: 10.3969/j.issn.1000-0690.2008.02.019. [40] 卓嘎, 徐祥德, 陈联寿. 2002.青藏高原夏季降水的水汽分布特征[J].气象科学, 22 (1): 1-8. doi: 10.3969/j.issn.1009-0827.2002.01.001Zhuo Ga, Xu Xiangde, Chen Lianshou. 2002. Water feature of summer precipitation on Tibetan Plateau [J]. Scientia Meteorologica Sinica, 22 (1): 1-8, doi: 10.3969/j.issn.1009-0827.2002. 01.001. [41] Zhou B T, Xu Y, Wu J, et al. 2016. Changes in temperature and precipitation extreme indices over China: Analysis of a high-resolution grid dataset [J]. International Journal of Climatology, 36: 1051-1066, doi: 10.1002/joc.4400. -