Unveiling global sub-daily precipitation extremes: Insights and development of the INTENSE Project 

Precipitation extremes result in flooding and droughts, causing substantial damages and loss of life. Understanding the variability of precipitation extremes with climate change is challenging, as we do no fully understand processes causing extreme precipitation under current climate variability. The INTENSE project focuses on understanding of the nature and drivers of global sub-daily precipitation extremes and change on societally relevant timescales. As part of this a Global sub-daily precipitation dataset has been collected, containing hourly rainfall data from approximately 25,000 rain gauges across over 200 territories, from a wide range of sources. This has been quality controlled using a rule-based open-source methodology, combining a number of checks against neighbouring gauges, known biases and errors, and thresholds based on the Expert Team on Climate Change Detection and Indices (ETCCDI) Climate Change Indices.   A set of global hydroclimatic indices have been produced, characterising key aspects of shorter duration precipitation variability, including intensity, duration and frequency properties. An analysis of the indices, trends and corresponding climatology is carried out, providing information on various sub-daily precipitation characteristics (including extremes) across large parts of the world. These indices are publicly available for as many gauges as possible, alongside a gridded dataset that also incorporates indices calculated for additional restricted-access gauge records. To progress further with this work, updates to the dataset are required, with work ongoing to update resources for 2016 onwards, and attempts to automate the process where open-source datasets are available. Any collaborations, information, suggested contacts and relevant resources for developing the dataset are welcomed.