applications of netcdf: the ncar cesm, and cmip5
TRANSCRIPT
Applications of netCDF:The NCAR CESM,
and CMIP5
2012 Unidata netCDF workshopGary Strand
NCAR/NESL/CGD
ATMOSPHERE
SEA ICE
BIOGEOCHEMICALCYCLES
SULFATEAEROSOLS
2010-onward
INTERACTIVEVEGETATION
CARBON/NITROGENCYCLE
DUST/SEA SPRAY/MINERAL AEROSOLS
SOLAR FORCINGVOLCANICAEROSOLS
ICE SHEET
OCEAN
SULFATEAEROSOLS
OCEAN
2000-2008
SOLAR FORCINGVOLCANICAEROSOLS
CARBONCYCLE
DUST/SEA SPRAY/MINERAL AEROSOLS
VEGETATION
ATMOSPHERE
SEA ICE
1990s
SULFATEAEROSOLS
ATMOSPHERE/LAND SURFACE/VEGETATION
OCEAN
SEA ICE
1970s-1980sATMOSPHERE/LAND SURFACE/VEGETATION
OCEAN
SEA ICE
Mid-1960s
ATMOSPHERE/LAND SURFACE
OCEAN
The Development of Climate ModelsPast, Present, and Future
SchematicallyProcesses
Grid
http://www.bom.gov.au/info/GreenhouseEffectAndClimateChange.pdf
Copyright © University Corporation for Atmospheric Research. Illustration by Paul Grabhorn.
What is “CESM”?
CommunityEarthSystemModel
CESM belongs to an elite category of computer-based simulations known as earth system models. Such models use mathematical formulas to recreate the chemical and physical processes that drive Earth’s climate. Extraordinarily sophisticated, they incorporate phenomena ranging from the effect that volcanic eruptions have on temperature patterns to the impact of shifting sea ice on sunlight in the atmosphere. What emerges from trillions of computer calculations is a picture of the world’s climate in all its complexity.
A CESM schematic
Courtesy Caitlin Alexander, ClimateSight
A brief history of the IPCC & data1990 - First Assessment (FAR)
5 modeling groups, 8 models, 7 simulations
2013 - Fifth Assessment (AR5)26 modeling groups, 59 models, 96 simulation types (decadal prediction and long-term)
1995 - Second Assessment (SAR)8 modeling groups, 10 models, 6 “IS92a” simulations
2001 - Third Assessment (TAR)7 modeling groups, 8 models, 6 “SRES” simulations
2007 - Fourth Assessment (AR4)16 modeling groups, 24 models, 12 simulation types
CMIP5 experimental designThe second large-scale coordination of climate modeling efforts, data analysis, data management and data dissemination by the global climate modeling community: 20+ global coupled climate models from many modeling centers located around the world.
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additional predictions Initialized in
‘01, ’02, ’03 … ’09
prediction with 2010 Pinatubo-
like eruption
alternative initialization strategies
AMIP
30-year hindcast and prediction ensembles: initialized 1960, 1980 &
2005
10-year hindcast & prediction ensembles:initialized 1960, 1965, …,
2005
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5%60-*!:7!D2)*.3(%2!/0..3-4!#$!?@ABC!1*2313&!,-*1%2(%#'!*+,*-%.*'(/7!!
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! T
Control, AMIP, &
20 C
RCP4.5, RCP8.5
ensembles: AMIP &
20 C
Radiation code sees 1XCO2 (1% or RCP4.5)
aqua
planet
Mid
-Hol
ocen
e &
LGM
last
m
illenn
ium
E-driven RCP8.5
E-driven 20 C
1%/yr CO2 (140 yrs) abrupt 4XCO2 (150 yrs)
fixed SST with 1x & 4xCO2 E-driven control with C-
cycle
CMIP5 Long-term Experiments
Carbon cycle sees 1XCO2 (1% or RCP4.5)
A visualization
A visualization II
Ensembles
286.5
287.0
287.5
288.0
288.5
289.0
800 825 850 875 900 925 950 975 1000 1025 1050 1075 1100 1125 1150 1175 1200
The NCAR CMIP5 model“Community Earth System Model”, version 1
• Fully-coupled global climate model• Different resolutions and components, depending on experiment
used for CMIP5used for CMIP5 under developmentunder development2x1 1x1 0.5x1 0.25x0.1
atmosphereatmosphere
land surface
ocean
144x96x26 288x192x26 576x384x32 1152x768x32
(280 km x 200 km) (140 km x 100 km) (70 km x 50 km) (35 km x 25 km)
144x96x15 288x192x15 576x384x15 1152x768x15
384x320x60 384x320x60 384x320x60 3600x2400x60
sea ice 384x320 384x320 384x320 3600x2400
The NCAR CMIP5 modelsFV 2° FV 1°
FV ½° FV ¼°
0
500
1,000
1,500
2,000
2,500
Jan-
04
Jul-
04
Jan-
05
Jul-
05
Jan-
06
Jul-
06
Jan-
07
Jul-
07
Jan-
08
Jul-
08
Jan-
09
Jul-
09
Jan-
10
Jul-
10
Jan-
11
Jul-
11
Jan-
12
Jul-
12
Archived CESM model data volume (TB)
NCAR’s climate model data
1960s - 1990sSelf-designed self-implemented binary formats
1990s-2000snetCDF-3 for model output, some input
todayall netCDF, all the time
A bit of history...
CESM output data arrangement
CMIP5 arrangementt0 t1 t2 ... tmf
1:
f2
: t0 t1 t2 ... tm
...
t0 t1 t2 ... tmfn
:
t0f1f2
...
fn
tmf1f2
...
fn
...
t1f1f2
...
fn
t2f1f2
...
fn
NCAR CMIP5 simulationsCMIP5 type Description #
piControl pre-industrial control 8
1% CO2 increase 1 percent per year CO2 5
historical Simulate 20th century climate and variations 18
historical variations Single forcing runs, etc. 38
paleoclimate Past climate (LGM, mid-Holocene, past 1000 years) 5
RCPs RCPs 2.6, 4.5, 6.0, 8.5 50
Decadal predictions Predictions (hindcast and forecast) 400
ESM Earth System Model (BGC, carbon cycle, &c) 16
Other Sensitivity and “idealized” Earths 17
Totals 557
IPCC AR5 variable counts1 hour 3 hour 6 hour daily month annual totals
aerosol
atmosphere
land
land ice
ocean
biogeochemistry
0 0 0 0 81 0 81
75 101 9 86 184 0 455
0 3 0 2 59 0 64
0 0 0 2 13 0 15
0 1 0 3 116 0 120
0 0 0 0 88 71 159
sea ice
totals
0 0 0 4 47 0 51
75 105 9 97 588 71 945
Data requirements
• Specific model fields, unchanged as well as derived• From atmosphere, land surface, ocean and sea ice,
aerosols, cloud feedbacks, and more• Monthly averages, daily and sub-daily, annual averages,
climatologies• Single model field per netCDF-3 file, all time samples• File sizes must be < 4 GB• Considerable amount of metadata required• Defined horizontal and vertical resolutions• Stringent data and metadata conventions, CF-compliant
Rather detailed (167 page PDF), including:
Metadata requirements
float TS(time, lat, lon) ; TS:units = "K" ; TS:long_name = "Surface temperature (radiative)" ; TS:cell_method = "time: mean" ;
float ts(time, lat, lon) ; ts:standard_name = "surface_temperature" ; ts:long_name = "Surface Temperature" ; ts:comment = "\"\"skin\"\" temperature (i.e., SST for open ocean)" ; ts:units = "K" ; ts:original_name = "TS" ; ts:cell_methods = "time: mean (interval: 30 days)" ; ts:cell_measures = "area: areacella" ; ts:history = "2011-07-22T00:05:32Z altered by CMOR: replaced missing value flag (-1e+32) with standard missing value (1e+20)." ; ts:missing_value = 1.e+20f ; ts:_FillValue = 1.e+20f ; ts:associated_files = "baseURL: http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation gridspecFile: gridspec_atmos_fx_CCSM4_historical_r0i0p0.nc areacella: areacella_fx_CCSM4_historical_r0i0p0.nc" ;
Standard model output for specific variable
As required by CMIP5
Metadata requirements :Conventions = "CF-1.0" ; :source = "CAM" ; :case = "b40.20th.track1.1deg.006" ; :title = "UNSET" ; :logname = "mai" ; :host = "be0809en.ucar.ed" ; :Version = "$Name$" ; :revision_Id = "$Id$" ; :initial_file = "b40.1850.track1.1deg.006.cam2.i.0893-01-01-00000.nc" ; :topography_file = "/fis/cgd/cseg/csm/inputdata/atm/cam/topo/USGS-gtopo30_0.9x1.25_remap_c051027.nc" ; :nco_openmp_thread_number = 1 ;
:institution = "NCAR (National Center for Atmospheric Research) Boulder, CO, USA" ; :institute_id = "NCAR" ; :experiment_id = "historical" ; :source = "CCSM4 (repository tag: ccsm4_0_beta43 compset: B20TRCN)" ; :model_id = "CCSM4" ; :forcing = "Sl GHG Vl SS Ds SD BC MD OC Oz AA LU" ; :parent_experiment_id = "piControl" ; :parent_experiment_rip = "r1i1p1" ; :branch_time = 937. ; :contact = "[email protected]" ; :references = "Gent P. R., et.al. 2011: The Community Climate System Model version 4. J. Climate, doi: 10.1175/2011JCLI4083.1" ; :initialization_method = 1 ; :physics_version = 1 ; :tracking_id = "d33ccf77-a73c-4f55-8f02-3a0734d51151" ; :acknowledgements = "The CESM project is supported by the National Science Foundation and the Office of Science (BER) of the U.S. Department of Energy.\n", "NCAR is sponsored by the National Science Foundation.\n", "Computing resources were provided by the Climate Simulation Laboratory at the NCAR Computational and Information Systems Laboratory (CISL),\n", "sponsored by the National Science Foundation and other agencies." ; :resolution = "f09_g16 (0.9x1.25_gx1v6)" ; :forcing_note = "Additional information on the external forcings used in this experiment can be found at\n", "http://www.cesm.ucar.edu/CMIP5/forcing_information" ; :product = "output" ; :experiment = "historical" ; :frequency = "mon" ; :creation_date = "2011-07-22T00:05:32Z" ; :history = "2011-07-22T00:05:32Z CMOR rewrote data to comply with CF standards and CMIP5 requirements." ; :Conventions = "CF-1.4" ; :project_id = "CMIP5" ; :table_id = "Table Amon (27 April 2011) a5a1c518f52ae340313ba0aada03f862" ; :title = "CCSM4 model output prepared for CMIP5 historical" ; :parent_experiment = "pre-industrial control" ; :modeling_realm = "atmos" ; :realization = 1 ; :cmor_version = "2.7.1" ;
Standard model global attributes
As required by CMIP5
CESM to CMIP5 workflow
time 1
field 1
field 2
field 3
...
field n
time 2
field 1
field 2
field 3
...
field n
time m
field 1
field 2
field 3
...
field n
...
CESM
HPC
GLADE
HPSS
ESG
publish
publish
publish
time 1 time 2 ... time m
time 1 time 2 ... time m
time 1 time 2 ... time m
field 1
field 2
field n
time 1 time 2 ... time mfield 3
DAV HPSS
proc
GLADE
time 1 time 2 ... time m
time 1 time 2 ... time m
field 1+2
field 3
field x
time 1 time 2 ... time m
CMOR
DAVGLADE
0
2,000
4,000
6,000
8,000
10,000
BC
CR
CA
WC
R
CC
CM
A
CN
RM
CSI
RO EC
GFD
L
GIS
S
IAP
ING
V
INM
CM
3
IPSL
MET
RI
MIR
OC
3
MIU
B
MPI
MR
I
NC
AR
Nor
Clim
U R
eadi
ng
UK
MO
CMIP3 data volumes by group (GB)
IPCC AR4 distribution
Modeling centers (16) Users (1000s)Gateway (1)
CMIP5 data volumes by group (TB)
0
50
100
150
200
250
300
350
400
BC
C
BN
U
CC
Cm
a
CM
CC
CN
RM
-CER
FAC
S
CSI
RO
-BO
M
CSI
RO
-QC
CC
E
FIO
ICH
EC
INM
IPSL
LASG
-CES
S
LASG
-IA
P
MIR
OC
MO
HC
MPI
-M
MR
I
NA
SA-G
ISS
NA
SA-G
MA
O
NC
C
NIC
AM
NO
AA
-GFD
L
NO
AA
-NC
EP
NSF
-DO
E-N
CA
R
IPCC AR5 distribution
Modeling centers (24)Gateways (9)Nodes (14)
Users (1000s)
Some lessons
•Know your data - very well•Exploit the pre-existing standards for your data AND metadata!
•Metadata - the more, the better•Publish your data - earn the credit•Make the lives of those who use your data easier - and that will make your life easier too
Some useful referencesCESM website:http://www.cesm.ucar.edu
CMIP5 website:http://cmip.llnl.gov
NetCDF Climate and Forecast (CF) Metadata Convention:http://cf-pcmdi.llnl.gov
NetCDF Operators (NCO):http://nco.sourceforge.net
Climate Data Operators (CDO):http://www.mpimet.mpg.de/fileadmin/software/cdo