Australian weather types, 1979-2015

This is a dataset of the weather systems present over Australia during the period 1979-2015, detected using ERA-Interim. The weather types are described in detail in Pepler et al. (2020), and used for assessing the influence of weather systems on rainfall changes in Pepler et al. (2021). Data is provided for all of Australia, but the weather types used are most useful for areas south of 25S. <br> There is one netCDF file for each year, which contains 60hourly weather type information on a 0.75 degree grid. Each grid cell has a number from 0 to 10, indicating the type of weather present at that location and time: Cyclone Only (1), Front Only (2), Thunderstorm Only (3), Cyclone-Front (4), Cyclone-Thunderstorm (5), Front-Thunderstorm (6), Triple Storm (7), High (8), Warm front (9), Unconfirmed front/cyclone (10), Undefined (0) <br> Cyclones are identified using a combination of the Murray and Simmonds (1991) and Wernli and Schwierz (2006) methods; cold fronts using a combination of the Simmonds et al. (2012) wind-based method and Berry et al. (2011) thermal front parameter method, with a 3 degree rgion of influence; and thunderstorms using the Dowdy (2020) dataset of calibrated thunderstorm environments for Australia. These three datasets are combined into 7 combined weather types to look at interactions and compounding effects. In addition to netCDF files, we provide CSVs of the monthly contribution of each weather type to rainfall for 15 regions of Australia (https://www.climatechangeinaustralia.gov.au/en/overview/methodology/nrm-regions), derived by combining the 6-hourly weather types data with a daily 0.05 dataset of gridded rainfall over Australia (AGCDv1, Jones et al. 2009). Similar CSVs can be generated for custom regions of Australia on request wuth the provision of an appropriate shapefile or netCDF mask. <br> This dataset was developed as part of the Victorian Water and Climate Initiative and supported by funding from the Victorian Department of Environment, Land, Water and Planning. For more information about VicWaCI see https://www.water.vic.gov.au/climate-change/climate-and-water-resources-research/the-victorian-water-and-climate-initiative <br> References: Pepler, A. S., A. J. Dowdy, P. van Rensch, I. Rudeva, J. L. Catto, and P. Hope, 2020: The contributions of fronts, lows and thunderstorms to southern Australian rainfall. <em>Clim. Dyn.</em>, <strong>55</strong>, 1489–1505, https://doi.org/10.1007/s00382-020-05338-8. Pepler, A. S., A. J. Dowdy, and P. Hope, 2021: The differing role of weather systems in southern Australian rainfall between 1979 – 1996 and 1997 – 2015. <em>Clim. Dyn.</em>, 2289–2302, https://doi.org/10.1007/s00382-020-05588-6.

本数据集收录了1979-2015年间澳大利亚上空的天气系统，数据基于ERA-Interim再分析资料识别得到。天气类型的详细说明参见Pepler等人（2020）的研究，该数据集同时被用于Pepler等人（2021）中评估天气系统对澳大利亚降雨变化的影响。数据集覆盖澳大利亚全域，但所使用的天气类型对南纬25°以南区域的适用性最佳。
数据集按年份分存为单个netCDF（网络通用数据格式）文件，每个文件包含0.75°分辨率网格上的逐6小时天气类型信息。每个网格格点均配有0至10的数值，用于表征对应位置和时刻的天气类型：仅气旋（1）、仅锋面（2）、仅雷暴（3）、气旋-锋面复合（4）、气旋-雷暴复合（5）、锋面-雷暴复合（6）、三重风暴（7）、高压（8）、暖锋（9）、未确认锋面/气旋（10）、未定义（0）。
气旋识别综合采用了Murray与Simmonds（1991）以及Wernli与Schwierz（2006）的方法；冷锋识别则结合了Simmonds等人（2012）基于风场的方法与Berry等人（2011）的热锋参数法，影响区域设定为3°；雷暴识别则采用了Dowdy（2020）针对澳大利亚校准后的雷暴环境数据集。上述三类识别结果被整合为7种复合天气类型，用于分析天气系统间的相互作用及叠加效应。
除netCDF文件外，本数据集还提供澳大利亚15个区域（https://www.climatechangeinaustralia.gov.au/en/overview/methodology/nrm-regions）各天气类型对降雨的月贡献量CSV（逗号分隔值）文件，该数据通过将逐6小时天气类型数据与澳大利亚逐日0.05°分辨率网格化降雨数据集（AGCDv1，Jones等人2009）结合计算得到。若用户提供合适的shapefile（矢量形状文件）或netCDF掩膜文件，可按需为自定义澳大利亚区域生成同类CSV文件。
本数据集作为维多利亚州水与气候倡议（Victorian Water and Climate Initiative, VicWaCI）的一部分开发完成，并由维多利亚州环境、土地、水与规划部提供资助。有关VicWaCI的更多详情可访问：https://www.water.vic.gov.au/climate-change/climate-and-water-resources-research/the-victorian-water-and-climate-initiative
参考文献：
1. Pepler A S, Dowdy A J, van Rensch P, Rudeva I, Catto J L, Hope P. 2020: Contributions of fronts, lows and thunderstorms to southern Australian rainfall. *Climatic Dynamics*, **55**: 1489–1505. https://doi.org/10.1007/s00382-020-05338-8
2. Pepler A S, Dowdy A J, Hope P. 2021: Differing roles of weather systems in southern Australian rainfall during 1979–1996 and 1997–2015. *Climatic Dynamics*, 2289–2302. https://doi.org/10.1007/s00382-020-05588-6