LOCA Derived Data
https://scenarios.globalchange.gov/loca-viewer/
National Climate Assessment Technical Support Unit
Original Release: March 2019
Last Updated: August 2019
*Note: Data for tmax5day, tmin5day, and tmin-max5day were updated August 2019*

The accompanying files contain data derived from the Coupled Model Intercomparison Project Phase 5 (CMIP5), downscaled using Localized Constructed Analogs (LOCA), for a subset of climate variables. LOCA uses statistical techniques to correct global climate model data for biases and downscale those data to a 1/16th degree spatial resolution.

See LOCA_variablelist.txt for a full descriptive list of LOCA derived climate variables.

Data are available in CSV (.csv) or netCDF (.nc) format. Note that data for all future time periods are given as the CHANGE relative to the historical climate. Also note that maps shown on the LOCA Viewer may not be displayed using the same units contained in these data files.

CSV files contain the following columns:
1. Longitude (decimal degrees)
2. Latitude (decimal degrees)
3. Historical Climate: Weighted multi-model mean for 1976-2005
4. Lower Emissions, Early 21st: Weighted multi-model mean change for 2016-2045 (compared to 1976-2005), under the RCP4.5 scenario
5. Lower Emissions, Mid 21st: Weighted multi-model mean change for 2036-2065 (compared to 1976-2005), under the RCP4.5 scenario
6. Lower Emissions, Late 21st: Weighted multi-model mean change for 2070-2099 (compared to 1976-2005), under the RCP4.5 scenario
7. Higher Emissions, Early 21st: Weighted multi-model mean change for 2016-2045 (compared to 1976-2005), under the RCP8.5 scenario
8. Higher Emissions, Mid 21st: Weighted multi-model mean change for 2036-2065 (compared to 1976-2005), under the RCP8.5 scenario
9. Higher Emissions, Late 21st: Weighted multi-model mean change for 2070-2099 (compared to 1976-2005), under the RCP8.5 scenario
10. Upper Bound, Early 21st: Mean change for 2016-2045 (compared to 1976-2005) from the three warmest or wettest models, under the RCP8.5 scenario
11. Upper Bound, Mid 21st: Mean change for 2036-2065 (compared to 1976-2005) from the three warmest or wettest models, under the RCP8.5 scenario
12. Upper Bound, Late 21st: Mean change for 2070-2099 (compared to 1976-2005) from the three warmest or wettest models, under the RCP8.5 scenario

Missing value/grid point over water, value = -999

For freeze-related/growing season variables:
No freeze (or other relevant threshold) occurrence, value = 999

Multi-model mean values are weighted averages, using the following 32 CMIP5 model ensemble:
ACCESS1-0, ACCESS1-3, bcc-csm1-1, bcc-csm1-1-m, CanESM2, CCSM4, CESM1-BGC, CESM1-CAM5, CMCC-CM, CMCC-CMS, CNRM-CM5, CSIRO-Mk3-6-0, EC EARTH, FGOALS-g2, GFDL-CM3, GFDL-ESM2G, GFDL-ESM2M, GISS-E2-H-p1, GISS-E2-R-p1, HadGEM2-AO, HadGEM2-CC, HadGEM2-ES, inmcm4, IPSL-CM5A-LR, IPSL-CM5A-MR, MIROC5, MIROC-ESM-CHEM, MIROC-ESM, MPI-ESM-LR, MPI-ESM-MR, MRI-CGCM3, NorESM1-M.

Ensemble averages for each grid cell were calculated using a vector of model weights, using the weighting strategy of Sanderson et al. (2017):
Sanderson, B. M., Wehner, M., and Knutti, R.: Skill and independence weighting for multi-model assessments, Geosci. Model Dev., 10, 2379-2395, https://doi.org/10.5194/gmd-10-2379-2017, 2017.

The "Upper Bound" product for temperature-related variables consists of averages from the three warmest models. The three models are consistent across all temperature variables and were determined as those producing the largest daily average temperature increase for 2070–2099 compared to 1976–2005 under the RCP8.5 scenario.
The "Upper Bound" product for precipitation-related variables consists of averages from the three wettest models. The three models are consistent across all precipitation variables and were determined as those producing the highest single day precipitation increase for 2070–2099 compared to 1976–2005 under the RCP8.5 scenario.

More information on CMIP5 can be found at: https://cmip.llnl.gov/cmip5/
More information on the LOCA dataset can be found at: http://loca.ucsd.edu/

LOCA dataset citations:
Pierce, D.W., D.R. Cayan, and B.L. Thrasher, 2014: Statistical downscaling using Localized Constructed Analogs (LOCA), J. Hydrometeorology, 15, 2558-2585. doi:10.1175/JHM-D-14-0082.1
Pierce, D.W., D.R. Cayan, E.P. Maurer, J.T. Abatzoglou, and K.C. Hegewisch, 2015: Improved bias correction techniques for hydrological simulations of climate change. J. Hydrometeorology, 16, 2421-2442. doi:10.1175/JHM-D-14-0236.1

For additional information on this derived dataset, please contact:
Laura Stevens
Research Scientist, National Climate Assessment
North Carolina State University
North Carolina Institute for Climate Studies
151 Patton Ave, Asheville, NC 28801
laura.stevens@noaa.gov
(828) 257-3006