California Applications Program / California Climate Change Center

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Scenarios -- Simulation Data and Information


Please click here for graphics comparing the global climate models being used for Scenarios

Please click here if you are interested in the downscaled data for ArcGIS

Three time periods and three types of data are being provided for the Assessment:
Time periods:
Types:

Downscaled Data

In the downscaled directory, you will be able to choose from two types of downscaling. The two types of downscaling are called a Bias Correction and Spatial Donwscaling (BCSD) and a Constructed Analogues (CA) downscaling. Ed Maurer and Hugo Hidalgo have a paper in press comparing these two methods:
Maurer, E.P., and H.G. Hidalgo, 2008: Utility of daily vs. monthly large-scale climate data: an intercomparison of two statistical downscaling methods, Hydrology and Earth System Science, 12, 551-563. (click here for article)
The analog method is described in:
Hugo G. Hidalgo, Michael D. Dettinger and Daniel R. Cayan, 2008: Downscaling with Constructed Analogues: Daily Precipitation and Temperature Fields over the United States, CEC Report CEC-500-2007-123, January 2008.
(download the report by clicking on the pdf file above or linking to the CEC report here)

A publication examining streamflow in California based on these results:

Maurer, E.P., H.G. Hidalgo, T. Das, M.D. Dettinger and D.R. Cayan, 2010: The utility of daily large-scale climate data in the assessment of climate change impacts on daily streamflow in California. Hydrol. Earth Syst. Sci., 14, 1125-1138, doi:10.5194/hess-14-1125-2010. (Click here for the article)

If you used BCSD data for the previous CAT report (2006), please note the values have changed. Here is a note from Ed about this:
...... The veg and snowband files are identical ..... 3 or 4 of the soil parameters for the American River basin (have changed) ....... Also, I did the additional calibration on the American after the last governor's study, so for that basin I would expect some changes with the new runs even for the two simulations we are repeating. Incidentally, I have also made improvements to the BCSD code over the past two years, so my downscaling for these same model runs will differ from last time as well. I don't know by how much, but it will not be identical.



Observed Data

We are also providing "observed" data on the VIC grid (1/8th degree). This data is described in:

Maurer, E.P., A.W. Wood, J.C. Adam, D.P. Lettenmaier, and B. Nijssen, 2002, A Long-Term Hydrologically-Based Data Set of Land Surface Fluxes and States for the Conterminous United States, J. Climate 15(22), 3237-3251

These input files can be found in the directory:

http://tenaya.ucsd.edu/wawona-t/vic_simulations_historical
The yearly files are in netCDF format. The files cover Jaunaury 1, 1949, through July 31, 2000.





Please click here for a file that contains the elevation of the downscaled 1/8th degree grid cells. This file is an ascii (text) file with columns of data for: latitude, longitude and elevation (in meters).




County information
David Lobell (dlobell@stanford.edu) has taken the listing of latitude and longitude for each of the downscaling methods and provided an additional columns containing the name of the county that is closest to the grid cell center (he found most centers to be inside a county but some are in the ocean). He also provides columns with the state names and FIPS (Federal Information Processing Standards) numbers for the state, county and location. David notes that ideally this file would also have elevation. If you have the ability to provide this please do and pass along to Mary (mtyree@ucsd.edu) and we will repost the files here. The files are csv (comma-seperated values). If you need these in another format please let Mary know. Thanks David!
Please click here for BCSD latitude, longitude, county file.
Please click here for CA latitude, longitude, county file.


Once you have chosen a particular downscaling method, you would next select which climate change scenario you wish to view. You have two options:
  • sresa2
  • sresb1

Once you have chosen which scenario to look at, you choose what time scale of output data you wish to use. Again, you have two options:

  • daily
  • monthly

Once you have chosen this, you can select which model you wish to look at.



**** Please note ****
  • The analog downscaling method requires daily data. Three of the 6 global models do not provide the daily data required. The three models that DO have data via the analog downscaling are: CNRM CM3, GFDL CM2.1 and NCAR PCM1.
  • A difference in the soil parameter sets used affected the Constructed Analog (CA) VIC simulations (fluxfiles; inputfiles not affected) for 67 grid points. The VIC model is being re-run and the updated files will be available in a special directory. Please check back here for the link when the data is ready. Please click here to see a list of the grid cells to be updated


Here you have 6 options:
  • cnrmcm3 (CNRM CM3)
  • gfdlcm21 (GFDL CM2.1)
  • miroc32med (CCSR MIROC 3.2 medium resolution)
  • mpiecham5 (MPI-OM ECHAM5)
  • ncarccsm3 (NCAR CCSM3.0)
  • ncarpcm1 (NCAR PCM1)

Once you have chosen which model to look at, you can choose what type of data you need. Here you have 4-5 options:

  • fluxfiles
  • inputfiles
  • petfiles
  • streamflow
  • tarfiles

fluxfiles
In the fluxfiles, you will find the output from the VIC simulation. VIC is the Variable Infiltration Capacity (VIC) Macroscale Hydrologic Model. To read more about this, please see the web page:
http://www.hydro.washington.edu/Lettenmaier/Models/VIC/VIChome.html
The fluxfiles will provide data from 1950 through 2099 (daily or monthly, depending on which directory you are in). The fluxfiles are arranged so there is one file per 'grid point' in our domain. The data is on an eighth degree grid (data is approx every 12km). The filenames will have the format 'fluxes_' followed by the latitude and longitude of the center of the grid square. For example, the file 'fluxes_35.4375_-120.4375' will have data for the grid square centered at 35.4375N and 120.4375W. The flux files are ascii (text) files with columns of information. These columns contain the variables (and units):
  • 1: year
  • 2: month
  • 3: day (if you are looking a daily data file)
  • 4: precipitation (mm/day)
  • 5: actual evapotranspiration (mm/day)
  • 6: runoff (mm/day)
  • 7: baseflow (mm/day)
  • 8: air temperature (deg C)
  • 9: soil moisture at top layer (mm)
  • 10: soil moisture at middle layer (mm)
  • 11: soil moisture at bottom layer (mm)
  • 12: net radiation at the surface, includes long and shortwave (W/m2)
  • 13: relative humidity (%)
  • 14: snow water equivalence (mm)
  • 15: 10m wind speed (m/s)
  • 16: fractional moisture in the entire soil column (fraction) (of porosity, 1=saturation)

Please note the VIC simulations use climatological wind speed (m/s). The climatological wind speed is an average for the period 1950 through 1999. The daily data for 1950-1999 is taken from Maurer et al. (2002). Maurer et al. (2002) derived the 10-m wind speed from daily 10-m wind fields of NCAR/NCEP Reanalysis (re-gridded to 1/8 degree resolution using linear interpolation). Please click here to see Maurer et al. (2002) for more information.

inputfiles
In the inputfiles, you will find the data used to drive the VIC simulation.
The inputfiles are only available daily and they provide data from 1950 through 2099. The inputfiles are in a format similar to the fluxfiles however the filename begins with 'data_'. These files are also ascii (text) with columns of information. These columns contain the variables (and units):

The BCSD files provide (ascii, text) columns of information:
  • 1: year
  • 2: month
  • 3: day
  • 4: precipitation (mm/day)
  • 5: maximum temperature (deg C)
  • 6: minimum temperature (deg C)
  • 7: 10m windspeed -- climatological (m/s)

The CA files provide (ascii, text) columns of information:

  • 1: precipitation (mm/day)
  • 2: maximum temperature (deg C)
  • 3: minimum temperature (deg C)
  • 4: 10m windspeed -- climatological (m/s)

petfiles
In the petfiles, you will find the potential evapotranspiration data
tarfiles

Several users will desire the entire array. These files will be provided by latitude and will be in the 'tarfiles' subdirectory. The files that start with 'data_' are gzipped tar files for the input data. The files that start with 'flux_' are gzipped tar files for the output (VIC model) data. Please note the CA downscaling provides data for latitudes in the range of 25N to 44N. The BCSD downscaling provides data for latitudes in the range of 31N to 43N. Below is a table detailing the progress in making the gzipped tar files.

MODEL
SRESA2
SRESB1
analog
bcsd
analog
bcsd
cnrmcm3
data ok
data ok
data ok
data ok
flux ok
flux ok
flux ok
flux ok
gfdlcm21
data ok
data ok
data ok
data ok
flux ok
flux ok
flux ok
flux ok
miroc32med
not avail
data ok
not avail
data ok
flux ok
flux ok
mpiecham5
not avail
data ok
not avail
data ok
flux ok
flux ok
ncarccsm3
not avail
data ok
not avail
data ok
flux ok
flux ok
ncarpcm1
data ok
data ok
data ok
data ok
flux ok
flux ok
flux ok
flux ok

ok ==> gzipped tar files are available
tbc ==> gzipped tar files are 'to be completed'


Soil depths

Tapash Das has provided us with a file of the depths of the 3 soil layers. To ascii this ascii data file please click here. The file has 5 columns: longitude, latitude, top soil layer depth, middle soil layer depth and bottom soil layer depth. These depths are graphically shown below. Over our region, the first two layers have the same depths (10cm and 30cm). The third layer varies.

Top
Middle
Bottom

streamflow
In the streamflow files, you will find data for particular streams.

***** 17 June 2008 *****

Replacement streamflow and fluxes files available

The streamflow routing for the CA (Constructed Analog) downscaling had errors for the rivers:

  • American River at Folsom Dam
  • Kings river

The soil files were updated for 67 grids -- these grids had information that differed from that used for the BCSD streamflow.

67 grids were re-run to update the files.

Updated files for fluxes and streamflow can be found in the rerun_soilparams subdirectory. For example, for the updated streamflow for the CA SRESA2 CNRM CM3 daily data, you would look at:
http://tenaya.ucsd.edu/wawona-t/ipcc4/downscaled/analog/sresa2/daily/cnrmcm3/rerun_soilparams/streamflow/

If you have any questions, please contact Mary Tyree: mtyree@ucsd.edu

**********************************

The streamflow files are available daily and monthly. These files have data for 1950 through 2099. The streamflow files are for select rivers (listed below) and the ascii (text) format in columns is year, month, day and streamflow in cfs. The rivers to choose from are:

Abbr
Name
Lat
Lon
VIC Lat
VIC Lon
SMITH Smith River at Jed Smith SP 41.7917 -124.0750 41.8125 -124.0625
SACDL Sacramento River at Delta 40.9397 -122.4161 40.9375 -122.4375
TRINI Trinity River at Trinity Reservoir 40.8010 -122.7620 40.8125 -122.8125
SHAST Sacramento River at Shasta Dam 40.7170 -122.4170 40.6875 -122.4375
SAC_B Sacramento River at Bend Bridge 40.2890 -122.1860 40.3125 -122.1875
OROVI Feather River at Oroville 39.5220 -121.5470 39.5625 -121.4375
SMART Yuba River at Smartville 39.2350 -121.2730 39.1875 -121.3125
NF_AM North Fork American River at North Fork Dam 39.1883 -120.7583 39.1875 -120.8125
FOL_I American River at Folsom Dam 38.6830 -121.1830 38.6875 -121.1875
CONSU Cosumnes River at Michigan Bar 38.5000 -121.0440 38.3125 -121.3125
PRD_C Mokelumne River at Pardee 38.3130 -120.7190 38.3125 -120.8125
N_HOG Calaveras River at New Hogan 38.1550 -120.8140 38.1875 -120.8125
N_MEL Stanislaus River at New Melones Dam 37.8520 -120.6370 37.9375 -120.5625
MERPH Merced River at Pohono Bridge 37.7167 -119.6650 37.9375 -119.5625
DPR_I Tuolumne River at New Don Pedro 37.6660 -120.4410 37.6875 -120.4375
LK_MC Merced River at Lake McClure 37.5220 -120.3000 37.5625 -120.3125
MILLE San Joaquin River at Millerton Lake 36.9840 -119.7230 36.9375 -119.6875
KINGS Kings River - Pine Flat Dam 36.8310 -119.3350 37.1875 -119.4375


Global Data
The following variables are availble on the global grid at the monthly time step:

Note: No uas for NCAR CCSM3. No vas for NCAR CCSM3. No uas for NCAR PCM1. No vas for NCAR PCM1. No rlus for NCAR PCM1. These variables may be available for a shorter time step.

By clicking on one of the time period links above, you will be taken to the home data directory for that frequency of simulation data. Subdirectories under each time frequency exist for the three simulations we will consider for the Assessment: 20C3M (historical simulation), SRESA2 (climate change simulation) and SRESB1 (climate change simulation). As an example, the monthly data for these three would be found in:

These are the same simulations that were used for the first biennial CAT Report.

By clicking on one of the simulation subdirectories listed above, you will be taken to the home data directory for that simulation. Here subdirectories are listed for each of the models under consideration for the Assessment (listed by modeling group and model name): CNRM CM3, GFDL CM2.1, CCSR MIROC3.2 (medium resolution), MPI ECHAM5, NCAR CCSM3 and NCAR PCM1. As an example, the monthly data for 20C3M for each of these 6 models would be found in:

The GFDL CM2.1 and NCAR PCM1 models were used for the first biennial CAT Report.

For most of the models, several simulations were made for the various scenarios. The particular runs chosen for this work are:

Model 20C3M SRESA2 SRESB1
CNRM CM3
run 1
run 1
run 1
GFDL CM2.1
run 2
run 1
run 1
CCSR MIROC3.2 (med)
run 1
run 1
run 1
MPI ECHAM5
run 4
run 1
run 1
NCAR CCSM3
run 5
run 5
run 5
NCAR PCM1
run 2
run 1
run 2


Please contact Mary Tyree with any questions:
mtyree@ucsd.edu
(858)822-1625