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iHESP Data Release - Phase 2

We are pleased to present the second increment of data from iHESP’s high-resolution, fully-coupled climate simulations. The first increment contained data from year 21 through 330 of the pre-industrial control simulation forced by perpetual 1850 conditions, and data from the 1950-control and the accompanying transient climate simulations that follow the HighResMIP protocol.

The second release consists of:

  • The remainder of the 1850 pre-industrial control climate simulation, for a total of 500 simulation years
  • 250 years of transient (historical and future) climate simulation for the 1850-2100 period. The future (2005-2100) period of the simulation uses the RCP8.5 scenario. 

All simulations were conducted with two different model resolutions: 1) high-resolution configuration that has 25 km for atmosphere and land model and 10 km for ocean and sea-ice model, and 2) low-resolution configuration that has 100 km for atmosphere, land, ocean and sea-ice model. The released datasets include high-resolution data for a comprehensive list of climate variables designed to study future climate change and its impact on society, environment, and economy simulations. The low-resolution equivalents will be made available soon. 

The datasets are available for download from this page. The total data volume is enormous, on the order of 500 TB. Due to storage space constraints, the released data sets will be for monthly means of, for example, three-dimensional ocean temperature, atmospheric winds, and precipitation. Some higher frequency (6-hourly or daily-mean) data sets will also be available upon request.

The iHESP data release represents our response and contribution to the call for the 2030 sustainable development goals by the UN, and the UN decade of Ocean Science and Sustainable Development 2021-2030 [1].

HIGHLIGHTS FROM IHESP HIGH-RESOLUTION CLIMATE SIMULATIONS

One of the key benefits of high-resolution climate modeling is its ability to directly simulate small-scale weather extremes, such as tropical cyclones, and mesoscale ocean features, such as ocean eddies, and thus improve our ability to project their potential changes in a future warming climate. Some preliminary analyses of iHESP high-resolution simulations show that model skill in simulating and projecting future changes in these small-scale phenomena is drastically improved over the standard low-resolution climate models currently used by the IPCC assessment reports.  For example, the observed number of tropical cyclones over the globe, averaged over the 1950-2018 period, is about 82 per year. The high-resolution iHESP model simulates 85 tropical cyclones per year during the same period, but the standard low-resolution model only simulates 23 tropical cyclones per year.  Interactions between tropical cyclones and upper ocean processes are also significantly improved in the high-resolution model simulation.  As an example, figure 1 shows the sea-surface temperature field from September 21, 2018 as represented in (top) high- and (bottom) low-resolution simulations. Right panels show a blow-up of the western North Atlantic region, with a cyclone track visible east of the Bahamas in the high-resolution run (top right), but not in the low-resolution run (bottom right). 

These simulations provide a tremendously rich resource that can facilitate exploration of the sensitivity to resolution of a wide array of atmospheric and oceanic phenomena and of poorly understood linkages between weather and climate. Climate simulations at such a high-resolution remain very resource-intensive, frontier activities that can only be performed occasionally on the most advanced high-performance computing systems by relatively large teams of scientists and software engineers. Consequently, the value of such simulation datasets for the broader climate science community is hard to overstate. We expect that the iHESP database will serve as a foundation for new science in the years to come, clarifying our vision of what the future might hold.

data-release2 

Figure 1: Comparison of high- vs low-resolution CESM simulated sea-surface temperature on September 21, 2018 (from Yeager et al. 2021 [2])

   

[1] https://en.unesco.org/ocean-decade

[2] Yeager, S.G., P. Chang, G. Danabasoglu, J. Edwards, N. Rosenbloom, Q. Zhang, D. Fu, X. Liu, F. Castruccio, 2021: Bringing the Future into Focus: Benefits and Challenges of High-Resolution Global Climate Change Simulations, Computing in Science & Engineering, doi:10.1109/MCSE.2021.3068244.