Abstract: As an ecological sensitivity region with the highest altitude, the Tibetan Plateau has been a hotspot in the study of long term trend and change of climate. The extreme weather events are related to the regional climate change and need to be analyzed deeply. In this study, based on the daily observed temperature and precipitation at 99 meteorological stations over the Tibetan Plateau during 1960 – 2012, a series of climate extreme indices are calculated. Firstly, the original meteorological observations are processed with quality control method. Then fifteen temperature extreme indices and eight precipitation extreme indices are computed by the R package RClimDex. There are ten indices determined by the absolute observed value and thirty indices determined by the threshold approach. This dataset will be useful for the research on extreme events occurring probability and the developing trend in the future. Combing use with regional statistical data, the climate extremes dataset can also reveal the impacts of climate extremes on agricultural and livestock production.
首先，校检各站点气象数据的txt文件，检测是否存在不符合逻辑的异常值，包括：（1）日最高温度Tmax小于日最低温度Tmin；（2）降水量Prcp小于0 mm。采用RClimDex1.0软件加载预处理得到的气象观测站点数据，运行质量控制功能模块，软件会自动识别–99.9为NA，并用NA替换异常值。其次，为了检测出气温和降水时间序列中的离群值，定义不超过或不小于青藏高原每日气候时间序列平均值3倍标准差范围为合理值范围，其离群值范围表达为[-∞, Mean – 3*Std] U [Mean+3*Std, +∞]。若原始气温及降水数据处于离群值范围[-∞, Mean – 3*Std]U[ Mean+3*Std, +∞]内，需再次对质量控制结果文件中的记录进行校检与筛选，剔除不合理的记录或将其设置为缺测值，确保数据质量得到严格控制；若无异常离群值，则可计算极端气候指数。
Zwiers F, Alexander L, Hegerl G, et al. Climate Extremes: Challenges in Estimating and Understanding Recent Changes in the Frequency and Intensity of Extreme Climate and Weather Events[M]// Ghassem R, James W. Climate Science for Serving Society. Netherlands: Springer, 2013.
Zhou B, Xu Y, Wu J, et al. Changes in temperature and precipitation extreme indices over China: analysis of a high‐resolution grid dataset[J]. International Journal of Climatology, 2016, 36(3): 1051–1066.