%0 Online Multimedia %A Mackie, Shona %A Seppala, Annika %A Smith, Inga %D 2020 %T Climate Data and Computing are Hotting Up! %U https://eresearchnz.figshare.com/articles/presentation/Climate_Data_and_Computing_are_Hotting_Up_/11929563 %R 10.6084/m9.figshare.11929563.v1 %2 https://eresearchnz.figshare.com/ndownloader/files/21897837 %K NeSI %K eResearch %K eResearch NZ 2020 %X Understanding our climate and how it changes in future is a topic of increasingly urgent research, with heightened levels of public and political support worldwide. Climate models, however, are necessarily big. In theory, they represent all physical processes from the top of the atmosphere to the bottom of the ocean, over land, water and sea ice, in 3-dimensional grid cells with a resolution of 1 degree or finer. The interaction and evolution of these processes is modelled with a temporal resolution of more than a single timestep per hour, and typically we need to run for at least 100 years. Furthermore, uncertainties and internal variability in the climate system mean that we run an ensemble rather than a single model run. The structure of climate models means they can usually be parallelized to a point, but they are not generally suitable for the distributed computing solutions that can be implemented in other fields. As well as being expensive to run, climate models produce a lot of data (PB scale). The idea is to capture the state of the whole world in a 3-dimensional mesh with a temporal resolution fine enough to see how it changes, and a spatial resolution fine enough to examine any physical process anywhere on Earth that might impact on climate. For example, one model component (atmosphere, ocean etc) can be made of 1.2 million grid points. Saving just one parameter daily for 100 years = 44 billion data points. 30 parameters from 6 ensemble simulations amounts to 8 trillion data points, just from one model component. These data have to be accessible so that we can do processing and monitoring of climate model runs while they are underway, and need to be securely archived in a way that makes them accessible for long term use, and shareable with collaborators both present and future, here in Aotearoa and abroad. Running a climate model is just the beginning of climate research, analysis of the data requires tools capable of accessing and handling large data volumes that are generally stored on remote servers, sometimes overseas, at a speed that makes interrogation and analysis practical.