LOCA Viewer

GRAPHICS INFORMATION

The Localized Constructed Analogs (LOCA) data set (http://loca.ucsd.edu/) uses statistical techniques to correct global climate model data for biases and downscale those data to a 1/16th degree spatial resolution. The scenarios products are described below.

Maps are presented for one historical and three future scenario products:

  • “Historical Climate” product — Averages from 32 model simulations of the 1976–2005 climate.
  • “Lower Emissions” product — Averages from 32 model simulations under the Representative Concentration Pathway (RCP) 4.5 scenario.
  • “Higher Emissions” product — Averages from 32 model simulations under the RCP8.5 scenario.
  • “Upper Bound” product, temperature-derived variables — Averages from the warmest three models (for the continental United States and adjacent portions of Canada and Mexico) at the end of the 21st century under the RCP8.5 scenario. The three models are consistent across all variables and were determined as those producing the largest daily average temperature increase for 2070–2099 compared to 1976–2005.
  • “Upper Bound” product, precipitation-derived variables — Averages from the wettest three models (for the continental United States and adjacent portions of Canada and Mexico) at the end of the 21st century under the RCP8.5 scenario. The three models are consistent across all variables and were determined as those producing the highest single day precipitation increase for 2070–2099 compared to 1976–2005.

The “Historical Climate”, “Lower Emissions”, and “Higher Emissions” maps use model-weighted averaging based on model performance in simulating the current climatology. The “Upper Bound” maps use equal model weighting.

File naming convention is given below:

  • Climatology (wclm) — Simulation of the Historical Climate (1976–2005 average)
  • Lo, Early 21st (wrcp45-1) — Lower Emissions simulated change for 2016–2045, compared to 1976–2005
  • Lo, Mid 21st (wrcp45-2) — Lower Emissions simulated change for 2036–2065, compared to 1976–2005
  • Lo, Late 21st (wrcp45-3) — Lower Emissions simulated change for 2070–2099, compared to 1976–2005
  • Hi, Early 21st (wrcp85-1) — Higher Emissions simulated change for 2016–2045, compared to 1976–2005
  • Hi, Mid 21st (wrcp85-2) — Higher Emissions simulated change for 2036–2065, compared to 1976–2005
  • Hi, Late 21st (wrcp85-3) — Higher Emissions simulated change for 2070–2099, compared to 1976–2005
  • Top, Early 21st (top3-1) — Upper Bound simulated change for 2016–2045, compared to 1976–2005
  • Top, Mid 21st (top3-2) — Upper Bound simulated change for 2036–2065, compared to 1976–2005
  • Top, Late 21st (top3-3) — Upper Bound simulated change for 2070–2099, compared to 1976–2005

The map values for the simulated changes for the future are simply the difference between the future period and the reference period in the specified units, except for the indices derived from precipitation, which are in percent change.

There are two additional sets of products, representing a pilot analysis to produce scenarios products for urban areas. These were produced for Los Angeles County and the Chicago Metropolitan Statistical Area and represent averages over these respective areas. The products are graphs depicting the multi-model mean and 5-95th percentile model distributions for the derived climate variables. File naming convention for the city products is:

  • ChicagoMSA_ — Lower Emissions (RCP4.5) and Higher Emissions (RCP8.5) simulated values for 1976–2005, 2016–2045, 2036–2065, and 2070–2099 averaged across all grid points in the Chicago Metropolitan Statistical Area
  • LAcounty_ — Lower Emissions (RCP4.5) and Higher Emissions (RCP8.5) simulated values for 1976–2005, 2016–2045, 2036–2065, and 2070–2099 averaged across all grid points in Los Angeles County