CCMVal

Overview of the New Lifetime Reference Simulations

in Support of SPARC Assessment

On behalf of the Lifetime Evaluation Activity for SPARC

SPARC

WCRP


General questions regarding the specifications of the simulations and external forcings can be directed to Martyn Chipperfield.
Please directly contact the appropriate scientists for questions regarding specific data sets (see below).

(A) Summary of the new SPARC Lifetime reference simulations
(B) SPARC Reference Simulation REF-C1: Reproducing the past: Forcings for a transient model simulation 1960 to 2006.
(C) SPARC Timeslice Simulation 2000: Forcings for a timeslice model simulation for 2000 conditions
(D) SPARC Timeslice Simulation 2100: Forcings for a timeslice model simulation for 2100 conditions


(A) Summary of CCMVal simulations in support of the SPARC Lifetimes Report


CCMs should perform 3 simulations. The timeslice run (REF-C1) is setup exactly the same way as the CCMVal-2 run REF-B2, with the addition of specified tropospheric OH and extra diagnostics/tracers. Groups should be able to reuse forcing datafiles prepared for CCMVal-2 in many cases.


(B) Reproducing the past: Observed forcings for REF-C1 (Core time period 1960 to 2006)


B1. Greenhouse Gases (CO2, CH4, N2O) in REF-C1

Greenhouse Gases (N2O, CH4, and CO2) from 1950 and 2006. The file gives surface volume mixing ratios of CH4 (ppbv), N2O (ppbv) and CO2 (ppmv) from IPCC [2001]. CH4 has been altered starting on 2002.49 using data from the NOAA Cooperative Global Air Samling Netwook to account for the observed lower growth rates of CH4 in recent years.


   
DOWNLOAD --->    Monthly mean data set (1850 - 2006)

    (Contact for questions: Doug Kinnison)


B2.   Halogens in REF-C1


Surface mixing ratios of Ozone Depleting Substances
(CFC-11, CFC-12, CFC-113, CFC-114, CFC-115, CCl4, CH3CCl3, HCFC-22, HCFC-141b, HCFC-142b, Halon1211, Halon1202, Halon1301, Halon2402, CH3Br and CH3Cl) in REF-C1 are taken from Table 5A-3 of WMO [2011]. The mixing ratios are calculated by a box model using yearly emissions and are given for the middle of the month. The time series does not contain a yearly variation in mixing ratios. Through 2008 the values are as much as possible forced to equal global estimates calculated from observations (for details see Chapter 5 of WMO [2011]). For models that do not wish to represent all the brominated and chlorinated species in Table 5A-3 of WMO [2011], the halogen content of species that are considered should be adjusted such that model inputs for total chlorine and total bromine match the time series of total chlorine and bromine given in this table.
We also provide time series of HFCs (i.e. non ODSs) from 1979 to 2050. All HFCs, except HFC-23, are created based on the High Scenario A1 provided by Guus Velders. HFC-23 is taken from Miller et al., (ACP 2010) and covers the time period from 1978 to 2009.


    DOWNLOAD ---> Monthly ODS data set (1951 to 2100) based on WMO (2011), Table 5A-3

    DOWNLOAD ---> Monthly HFC data set (1978 to 2050)
    (Contact for questions: Qing Liang)


Emission Fluxes of Additional ODS
(CFC-11, CFC-12, CH3CCl3, HCFC-22). The emission fluxes for the additional (uncoupled) chlorine tracers are provided in the NetCDF files below, along with a ReadMe file (pdf). There are two separate files for 1951-1995 and 1996-2010 because the geographical fractionation for CFC-11 and CFC-12 change between the two files. *** We will soon receive new emissions for the period 2002-2010 (based on results in SPARC Report Chapter 4) and when we do so we will update the emissions files. The current file can still be used for the 2000 timeslice run and to start the transient run. *** For the 2100 timeslice run (T2100) these emission fluxes should be set to zero.


    DOWNLOAD ---> ODS Emissions 1951-1995

    DOWNLOAD ---> ODS Emissions 1996-2010
    DOWNLOAD ---> ReadMe File
    (Contact for questions: Qing Liang)


B3.   Sea Surface Temperatures and Sea Ice Concentrations in REF-C1


Sea surface temperatures and sea ice concentrations in REF-C1 are prescribed as monthly mean
boundary conditions
following the global sea ice concentration and sea surface temperature (HadISST1) data set provided by the UK Met Office Hadley Centre [Rayner et al., 2003]. This data set is based on blended satellite and in situ observations. To prepare the data for use in forcing a model, and in particular to correct for the loss of variance due to time-interpolation of monthly mean data, it is recommended that each group follows the procedures described on the C20C project web (see http://grads.iges.org/c20c/c20c_forcing/karling_instruct.html). This describes how to apply the AMIP II variance correction method (see http://www-pcmdi.llnl.gov/projects/amip/AMIP2EXPDSN/BCS/amip2bcs.php for details) to the HadISST1 data.

    DOWNLOAD Hadley Centre Sea Ice and SST data set (HadISST) --->   http://www.hadobs.org/: Follow the link "Marine Data" and "HadISST -     Globally complete sea-ice and sea-surface temperature".


B4.   Solar Cycle in REF-C1


Solar Irradiance Data
for the REF-C1 simulations are specified at the SOLARIS website:
 
To account for the highly variable and wavelength-dependent changes in solar irradiance, daily spectrally resolved solar irradiance data from 1 Jan 1950 to 31 Dec 2006 (in W/m2/nm) are provided. The data are derived with the method described in Lean et al. [2005] and are available with the following spectral resolution: 1 nm bins from 0 to 750 nm; 5 nm bins from 750 to 5000 nm; 10 nm bins from 5000 to 10000 nm; 50 nm bins from 10000 to 100000 nm. Each modeling group is required to integrate these data over the individual wavelength intervals (a) in their radiation scheme (to adjust the shortwave heating rates) and (b) in their chemistry scheme (to adjust the photolysis rates). It is recommended to use the provided solar flux data directly (integrated over the respective intervals in the radiation and chemistry schemes), rather than a parameterization with the F10.7 cm radio flux previously used. Additional information as well as the data can be found on the SOLARIS website.


    GO TO ---> 
SOLARIS website to download the data
    (Contact for questions: Katja Matthes)


B5.   Assimilated Quasi-Biennial Oscillation (QBO)  in REF-C1

The QBO is generally described by zonal wind profiles measured at the equator. The QBO is an internal mode of variability of the atmosphere that dominates the interannual variability in wind in the tropical stratosphere and contributes to the variability in the extratropical dynamics. It is recognized that the QBO is important for understanding interannual variability in ozone and other constituents of the middle atmosphere, in the tropics and extratropics. Currently only a few atmospheric GCMs or CCMs simulate a realistic QBO and hence QBO related influences. Simulated QBOs are generally independent of observed time series because their phase evolutions are not bound by external boundary conditions. Realistic simulated QBOs, however, have similar periods, amplitudes and composite structures in observations. The assimilation of the QBO, for example by a relaxation of zonal winds in the QBO domain ("nudging"), hence may be useful for two reasons: First to obtain a QBO in GCMs that do not simulate the QBO internally, so that for example QBO effects on the general circulation are present; and second to synchronize the QBO simulated in a GCM with a given QBO time series, so that simulated QBO effects, for example on ozone, can be compared to observed signals.


GO TO --->  QBO website to download the data

(Contact for questions:
Marco Giorgetta
)


B6.   Surface Sulphate Area Densities (SADs) in REF-C1


Surface Sulphate Area Densitites (SADs)
from observations are considered in REF-C1. A monthly zonal mean time series for SADs from 1979 to 2004 was created using data from the SAGE I, SAGE II, SAM II, and SME instruments (units square microns per cubic centimeter). This time series was published in SPARC [2006]. In addition, uncertainties of the SAGE II data set are described in detail in Thomason et al. [2007]. The altitude and latitude range of this data set is 12 - 40 km and 80°S – 80°N respectively. The SPARC SAD data set does have data gaps, which occur mainly in lower tropical altitudes (below 16 km) and during the El Chichón period. Above 26 km there are large data gaps in the mid-to-high latitude region. There are also missing data at all altitudes in the high latitude polar regions. The NCAR group modified this new SPARC SAD data set for CCM applications by filling the missing data using a linear interpolation approach in altitude and latitude. Large gaps of data above 26 km were filled with background values of 0.01 square microns per cubic centimeter. The gaps in the upper troposphere, tropical latitudes, between 1982 and 1984 were not filled. Missing values are indicated with values lower and equal 0.

For the period between 1950-1962, 1968-1979, and 2005-2100, monthly means of a five-year period 1998 to 2002 with background aerosols were adopted. Further, the Agung eruption in 1963 was implemented (by Andrea Stenke). As a remedy we follow the method described in Dameris et al. [2005]. The well documented years following the eruption of Mt. Pinatubo (1991–1994) have been adopted and associated with the period 1963–1966 with modifications based on published results to account for differences in total mass of sulfate aerosols in the stratosphere, in maximum height of the eruption plumes, and in the volcanoes’ geographical location. Above the maximum vertical extent of Agung’s eruption plume the annual mean of 1979 has been incorporated. For the new CCMVal simulations, we recommend using the new modified SPARC SAD time series described above, in particular for those models that have a heterogeneous chemistry halogen activation approach based solely on the occurrence of super cooled ternary (STS) PSCs.

   
DOWNLOAD --->
SAD data set 1950 to 2100 (14.6 MB)
(Contact for questions:
Simone Tilmes and Doug Kinnison)


B7.   Heating rates from volcanic aerosol in REF-C1

 

Stratospheric warming and tropospheric-surface cooling due to volcanic eruptions are either calculated on line by using aerosol data or by prescribing heating rates and surface forcing. For those models that don’t calculate this effect online, pre-calculated zonal mean aerosol heating rates (K/day) and net surface radiative forcing (W/m2) monthly means from January 1950 to December 1999 for all-sky condition are available on the CCMVal website. They were calculated using volcanic aerosol parameters from Sato et al. [1993], Hansen et al. [2002] and GISS ModelE radiative routines and climatology [Schmidt et al., 2006; G. Stenchikov and L. Oman, pers. communication, 2007]. In addition to the larger eruption (Agung, 1963; El Chichón, 1982; Pinatubo, 1991) smaller ones like Fernandina (1968 in Galapagos) and Fuego (1974 in Guatemala) are included. Surface radiative forcing is negative corresponding to cooling caused by volcanic aerosols. The right way to use these data sets to mimic effect of volcanic eruptions would be to apply heating rates to the atmosphere and cooling flux to the surface. Heating rates and surface forcing would characterize the entire volcanic effect that is: stratospheric warming and tropospheric-surface cooling. If the focus is on stratospheric processes only aerosol heating rates could be used without causing any problem.


   
DOWNLOAD --->    hrates_readascii.f, hrates.ascii, sfc_forcing.ascii
   
(Contact for questions: Gera Stenchikov)


B8.   Ozone and Aerosol Precursors in REF-C1

Emissions of ozone and aerosol precursors (CO, NMVOC, NOx and SO2) are averaged over the years 1998 to 2000 and are taken from an extended data set of the REanalysis of the TROpospheric chemical composition (RETRO) project [Schultz et al., 2007, see http://retro.enes.org]. The RETRO emissions inventory is a comprehensive global gridded data set for anthropogenic and wildfire emissions over the past 40 years. The data set comprises a high level of detail in the speciation of NMVOC compounds. The data originates from a large variety of sources, including the TNO TEAM inventory, information on burnt area statistics, the regional fire model Reg-FIRM, and satellite data. In case of SO2, RETRO only provides biomass burning related emissions. Therefore, this data is combined with an interpolated version of EDGAR-HYDE 1.3 [Van Aardenne et al., 2001] and EDGAR 32FT2000 [Olivier et al., 2005; Van Aardenne et al., 2005]. For the spin-up period from 1950 to 1959 we recommend using the 1960 values from this data set. The data set will be extended through 2006 by using trend estimates and will be harmonized so that regional totals are the same as in RETRO for the year 2000.


    GO TO --->  Ozone and aerosol precursor website to download the data
   
(Contact for questions: Andreas Baumgärnter)


B9.   Tropospheric OH

Tropospheric OH 

Models which do not calculate their own realistic values of tropospheric OH should read in the reference fields supplied here.

    This approach was used in the recent TransCom CH4 intercomparison study (Patra et al., 2011).
    GO TO --->  OH data
(Contact for questions: Martyn Chipperfield )




(C) Timeslice run 2000

 


C1.   Other Forcings in T2000


Use values for 2000 from forcing files for REF-C1.

 


C2.   Halogens in T2000


Surface mixing ratios of Ozone Depleting Substances
(CFCs, HCFCs, HFCs etc). Use values for January 2000 from forcing files for REF-C1 (above).


Emission Fluxes of Additional ODS
(CFC-11, CFC-12, CH3CCl3, HCFC-22). Use values for 2000 (see REF-C1 forcings above).


(D) Timeslice Run 2100




D1.   Other Forcings in T2100


The T2100 runs should be initialised using output from your CCMVal-2 REF B-2 run for 2100.
The run should then use the 2100 GHG/SST forcings for CCMVal-2 B-2 perpetually.

 


D2. Halogens in T2100


Surface mixing ratios of Ozone Depleting Substances (CFCs, HCFCs, HFCs etc). Use values for January 2100 from forcing files for REF-C1 (above).

The additional emission-based ODS tracers (CFC-11, CFC-12, CH3CCl3, HCFC-22) should be initialised using the January 2100 output from the CCMVal REF B-2 run (i.e. the same distribution as the surface vmr tracers) EXCEPT for CH3CCl3 will be be zero by this time. CH3CCl3 should be initialised using the January 2000 values used in the T2100 timeslice run. The Emission fluxes of these additional ODS tracers should be set to zero (see section B2). These tracers will then behave as time-decaying tracers.



Last modified:  September 1, 2011
by Martyn Chipperfield