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This page contains information about the Radon-Lead-Beryllium simulation in GEOS-Chem.
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__FORCETOC__
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'''''[[Tagged O3 simulation|Previous]] | [[Guide to GEOS-Chem simulations|Next]] | [[Guide to GEOS-Chem simulations]]'''''
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#[[GEOS-Chem chemistry mechanisms|Simulations using KPP-built mechanisms (carbon, fullchem, Hg)]]
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#[[Aerosol-only simulation]]
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#[[CH4 simulation]]
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#[[CO2 simulation]]
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#[[Metals simulation]]
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#[[Mercury|Hg simulation]]
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#[[POPs simulation]]
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#[[Tagged CO simulation]]
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#[[Tagged O3 simulation]]
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#<span style="color:blue">'''TransportTracers simulation'''</span>
  
== Overview ==
 
  
The Rn-Pb-Be simulation in GEOS-Chem was based on that of the old Harvard/GISS CTM model.  The current simulation follows ''Liu et al'' [2001].
+
This page contains information about the TransportTracers (formerly Rn-Pb-Be) simulation in GEOS-Chem.
  
The standard Rn-Pb-Be simulation uses the following tracers:
+
== Overview ==
  
#Rn<sup>222</sup>, which is emitted naturally from soils
+
The Rn-Pb-Be simulation in GEOS-Chem was based on that of the old Harvard/GISS CTM model. The current simulation follows [http://acmg.seas.harvard.edu/publications/2001/liu2001.pdf Liu et al (2001)]. 
#Pb<sup>210</sup>, which is the primary decay product of Rn<sup>222</sup>
+
#Be<sup>7</sup>, which is produced by cosmic rays in the stratosphere and upper atmosphere
+
  
This simulation is most frequently used to validate the convection and advection processes in GEOS-Chem.
+
In [[GEOS-Chem 12#12.2.0|GEOS-Chem 12.2.0]] the Rn-Pb-Be simulation was extended to include additional passive species for benchmarking purposes and for diagnosing transport in GEOS-Chem. At this time the simulation was renamed to the '''''TransportTracer simulation'''''.  
  
<div style="color: #aa0000; background: #eeeeee;border: 3px solid red; padding: 1em; margin: auto; width: 90%; "> '''<p>Prior to [[GEOS-Chem v9-02]], the Rn-Pb-Be simulation was not compatible with the [[Boundary_layer_mixing#VDIFF|non-local PBL mixing scheme]]. If you are running the Rn-Pb-Be simulation with any version of GEOS-Chem prior to v9-02, you must select [[Boundary_layer_mixing#TURBDAY|the TURBDAY PBL mixing scheme]] for the Rn-Pb-Be simulation. [[#Non-local PBL mixing|See below]] for more information.</p><p>&mdash; Bob Yantosca, 28 May 2014</p>'''</div>
+
In [[GEOS-Chem 14.2.0]] the TransportTracers simulation was further modified so that species names and definitions are now consistent with GMAO's tracer gridded component (aka TR_GridComp). This will facilitate comparison of transport within GEOS-Chem, GCHP, and GEOS.
  
=== Sources ===
+
=== List of species ===
  
{| border=1 cellspacing=0 cellpadding=5  
+
The transport tracers are summarized below.
 +
 
 +
{| border=1 cellspacing=0 cellpadding=5
 
|-bgcolor="#CCCCCC"
 
|-bgcolor="#CCCCCC"
!width="100px"|Species
+
!width="100px"|Species name
!width="750px"|Chemical source
+
!width="200px"|Description
 +
!width="300px"|Source
 +
!width="300px"|Sink
 +
!width="300px"|Purpose
  
 
|-valign="top"
 
|-valign="top"
|Rn<sup>222</sup>
+
|Rn222
|The source of Rn<sup>222</sup> is determined as follows (cf. ''Jacob et al'' [1997]):
+
|Radon-222 isotope
 +
|
 +
*Emitted naturally from soils based on [https://acp.copernicus.org/articles/21/1861/2021/ Zhang et al., 2021].
 +
|
 +
*Half-life of 3.83 days (Liu at al., 2001).
 +
**Decays into Pb<sup>210</sup> according to the exponential law:
 +
::<tt>EXP( -&Delta;T * 2.097d-6  )</tt>
 +
|Used to evaluate convection over land and strat-trop exchange
  
{| border=1 cellspacing=0 cellpadding=5
+
|-valign="top"
|-valign="top" bgcolor="#CCFFFF"
+
|Pb210
!width="100px"|Latitudes
+
|Lead-210 isotope
!width="500px"|Rn<sup>222</sup> Emission
+
|
 +
*Radioactive decay from Rn<sup>222</sup> according to the exponential law:
 +
::<tt>EXP( -&Delta;T * 2.097d-6  )</tt>
 +
::Where &Delta;T is the emission timestep in seconds.
 +
|
 +
*Half-life of 22.3 years (Liu et al., 2001).
 +
**Decays according to the exponential law:
 +
::<tt>EXP( -&Delta;T * 9.725d-10 )</tt>
 +
*Wet deposition
 +
*Dry deposition
 +
|Used to evaluate wet scavenging and transport
  
 
|-valign="top"
 
|-valign="top"
| 90&deg;N - 70&deg;N
+
|Pb210s
 +
|Lead-210 isotope stratospheric-source tracer
 
|
 
|
*Everywhere: <tt>0.0 atoms/cm2/s</tt>
+
*Same as Pb210 (restricted to the stratosphere)
 +
|
 +
*Same as Pb210
 +
|Used to evaluate strat-trop exchange
  
 
|-valign="top"
 
|-valign="top"
|70&deg;N - 60&deg;N
+
|Be7
 +
|Beryllium-7 isotope
 
|
 
|
*Everywhere: <tt>0.005 atoms/cm2/s</tt>
+
*Produced by cosmic rays as described in [https://link.springer.com/chapter/10.1007/978-3-642-46079-1_7 Lal and B. Peters, 1967]
*Reduce emissions by a factor of 3 where surface temperature < 0&deg; C
+
*Plus the following modifications from Liu et al. (2001):
 +
#Replace data at (0 hPa altitude, 70&deg;S latitude) following Koch (1996):
 +
#*old value = <tt>3000 disintegrations/g air/s</tt>
 +
#*new value = <tt>1900 disintegrations/g air/s</tt>
 +
#The original Lal & Peters data ended at 70&deg;S
 +
#*Copy the data values at 70&deg;S to 80&deg;S and 90&deg;S at all levels
 +
|
 +
*Half-life of 53.3 days (Liu et al., 2001).
 +
**Decays according to the exponential law:
 +
::<tt>EXP( -&Delta;T * 1.506d-7  )</tt>
 +
*Wet deposition
 +
*Dry deposition
 +
|Used to evaluate wet scavenging and strat-trop exchange
  
 
|-valign="top"
 
|-valign="top"
|60&deg;N - 60&deg;S
+
|Be7s
 +
|Beryllium-7 isotope stratospheric source tracer
 
|
 
|
*Over land: <tt>1 atom/cm2/s</tt>
+
*Same as Be7 (restricted to the stratosphere)
*Over oceans: <tt>0.005 atoms/cm2/s</tt>
+
|
*Reduce emissions by a factor of 3 where surface temperature < 0&deg; C
+
*Same as Be7
 +
|Used to evaluate strat-trop exchange
  
 
|-valign="top"
 
|-valign="top"
|60&deg;S - 70&deg;S
+
|Be10
 +
|Beryllium-10 isotope
 
|
 
|
*Everywhere: <tt>0.005 atoms/cm2/s</tt>
+
*Be<sup>10</sup> has an identical source distribution as Be<sup>7</sup> following Koch and Rind (1998).
*Reduce emissions by a factor of 3 where surface temperature < 0&deg; C
+
|
 +
*Half-life of 5.84e8 days (Koch and Rind, 1998).
 +
**Decays according to the exponential law:
 +
::<tt>EXP( -&Delta;T * 1.506d-7  )</tt>
 +
*Wet deposition
 +
*Dry deposition
 +
|Used to evaluate wet scavenging and strat-trop exchange
  
 
|-valign="top"
 
|-valign="top"
| 70&deg;S - 90&deg;S
+
|Be10s
 +
|Beryllium-10 isotope stratospheric source tracer
 +
|
 +
*Same as Be10 (restricted to the stratosphere)
 
|
 
|
*Everywhere: <tt>0.0 atoms/cm2/s</tt>
+
*Same as Be10
|}
+
|Used to evaluate strat-trop exchange
  
 
|-valign="top"
 
|-valign="top"
|Pb<sup>210</sup>
+
|PassiveTracer
|Radioactive decay from Rn<sup>222</sup> according to the exponential law:
+
|Passive tracer with initial concentration of 100 ppb
*<tt>EXP( -&Delta;T * 2.097d-6  )</tt>
+
|
Where &Delta;T is the emission timestep in seconds.
+
*None
 +
|
 +
*None
 +
|Used to evaluate mass conservation in transport
  
 
|-valign="top"
 
|-valign="top"
|Be<sup>7</sup>
+
|SF6
|The source of Be<sup>7</sup> is taken from the following reference:
+
|Sulfur hexafluoride
*Lal, D., and B. Peters, ''Cosmic ray produced radioactivity on the Earth''. <u>Handbuch der Physik</u>, '''46'''/2, 551-612, edited by K. Sitte, Springer-Verlag, New York, 1967.
+
|
 +
*Anthropogenic emissions from EDGAR v4.2
 +
|
 +
*None
 +
|Used to evaluate inter-hemispheric transport of anthropogenic emissions
  
with the following modifications (cf. ''Liu et al'' [2001]):
+
|-valign="top"
#Replace data at (0 hPa altitude, 70&deg;S latitude) following ''Koch'' [1996]:
+
|CH3I
#*old value = <tt>3000 disintegrations/g air/s</tt>
+
|Methyl iodide
#*new value = <tt>1900 disintegrations/g air/s</tt>
+
|
#The original Lal & Peters data ended at 70&deg;S
+
*Emissions over the oceans of 1 molec/cm2/s
#*Copy the data values at 70&deg;S to 80&deg;S and 90&deg;S at all levels
+
|
 +
*5-day e-folding lifetime
 +
|Used to evaluate marine convection
  
|}
+
|-valign="top"
 +
|CO_25
 +
|Anthropogenic CO 25-day tracer
 +
|
 +
*Emissions from CEDS v2
 +
|
 +
*25-day e-folding lifetime
 +
|
  
--[[User:Bmy|Bob Y.]] ([[User talk:Bmy|talk]]) 19:26, 15 June 2015 (UTC)
+
|-valign="top"
 +
|CO_50
 +
|Anthropogenic CO 50-day tracer
 +
|
 +
*Emissions from CEDS v2
 +
|
 +
*50-day e-folding lifetime
 +
|
  
=== Sinks ===
+
|-valign="top"
 +
|e90
 +
|Constant burden 90-day tracer
 +
|
 +
*Emitted globally at the surface such that the mixing ratio is maintained at 100 ppbv
 +
|
 +
*90-day e-folding lifetime
 +
|
  
The table below shows the sinks for Rn<sup>222</sup>, Pb<sup>210</sup>, and Be<sup>7</sup>.  In the equations below, &Delta;T is the emission timestep in seconds.
+
|-valign="top"
 +
|e90_n
 +
|Constant burden Northern Hemisphere 90-day tracer
 +
|
 +
*Emitted at the surface such that the mixing ratio is maintained at 100 ppbv. Emissions source is restricted to 40N - 90N.
 +
|
 +
*90-day e-folding lifetime
 +
|
  
{| border=1 cellspacing=0 cellpadding=5
+
|-valign="top"
|-bgcolor="#CCCCCC"
+
|e90_s
!width="100px"|Species
+
|Constant burden Southern Hemisphere 90-day tracer
!width="525px"|Chemical sink
+
|
!width="100px"|Drydep sink?
+
*Emitted at the surface such that the mixing ratio is maintained at 100 ppbv. Emissions source is restricted to 90S - 40S.
!width="100px"|Wetdep sink?
+
|
 +
*90-day e-folding lifetime
 +
|
  
 
|-valign="top"
 
|-valign="top"
|Rn<sup>222</sup>
+
|aoa
|Decays into Pb<sup>210</sup> according to the exponential law:
+
|Age of air uniform source tracer
*<tt>EXP( -&Delta;T * 2.097d-6  )</tt>
+
|
|no
+
*Increases by a value of 1 each emissions timestep
|no
+
|
 +
*Sink at the surface
 +
|Used for evaluating residual circulation and mixing
  
 
|-valign="top"
 
|-valign="top"
|Pb<sup>210</sup>
+
|aoa_bl
|Decays according to the exponential law:
+
|Age of air uniform source tracer with sink restricted to the boundary layer
*<tt>EXP( -&Delta;T * 9.725d-10 )</tt>
+
|
|yes
+
*Increases by a value of 1 each emissions timestep
|yes
+
|
 +
*Sink in the boundary layer
 +
|Used for evaluating residual circulation and mixing
  
 
|-valign="top"
 
|-valign="top"
|Be<sup>7</sup>
+
|aoa_nh
|Decays according to the exponential law:
+
|Age of air uniform source tracer with sink restricted to a zone in the Northern Hemisphere
*<tt>EXP( -&Delta;T * 1.506d-7  )</tt>
+
|
|yes
+
*Increases by a value of 1 each emissions timestep
|yes
+
|
 +
*Sink at 30N - 50N
 +
|Used for evaluating residual circulation and mixing
  
|}
+
|-valign="top"
 +
|nh_5
 +
|Northern Hemisphere 5-day tracer
 +
|
 +
*Constant source of 100 ppbv at latitudes 30N - 50N
 +
|
 +
*5-day e-folding lifetime
 +
|
  
--[[User:Bmy|Bob Y.]] ([[User talk:Bmy|talk]]) 18:48, 15 June 2015 (UTC)
+
|-valign="top"
 +
|nh_50
 +
|Northern Hemisphere 50-day tracer
 +
|
 +
*Constant source of 100 ppbv at latitudes 30N - 50N
 +
|
 +
*50-day e-folding lifetime
 +
|
  
== Dry deposition ==
+
|-valign="top"
 +
|st80_25
 +
|Stratospheric source 25-day tracer
 +
|
 +
*Constant source of 200 ppbv above 80 hPa
 +
|
 +
*25-day e-folding lifetime
 +
|
  
The following dry deposition updates were recently made to the GEOS-Chem Rn-Pb-Be simulation:
 
 
=== GEOS-Chem v10-01 ===
 
 
In [[GEOS-Chem v10-01]] and higher versions, dry deposition of advected tracers was centralized into the module <tt>GeosCore/mixing_mod.F90</tt>.  This has the following implications for the GEOS-Chem Rn-Pb-Be simulation:
 
 
#Routine <tt>DRYFLXRnPbBe</tt>&mdash;which is where dry deposition losses had been applied to Pb<sup>210</sup> and Be<sup>7</sup> in prior GEOS-Chem versions&mdash;has now been removed from module <tt>GeosCore/drydep_mod.F</tt>.  This routine has been rendered obsolete.
 
#Routine  <tt>DO_TEND</tt> in module <tt>GeosCore/mixing_mod.F90</tt> now computes the ND44 diagnostic (i.e. archival of Pb<sup>210</sup> and Be<sup>7</sup> dry deposition fluxes.  This diagnostic was formerly updated in routine <tt>DRYFLXRnPbBe</tt>, which has since been removed.
 
#<span style="color:red">'''IMPORTANT!!! GEOS-Chem v10-01 now archives the ND44 dry deposition fluxes (i.e. GAMAP category <tt>DRYD-FLX</tt>) as <tt>molec/cm2/s</tt> for ALL simulations.  (In prior GEOS-Chem versions, the ND44 drydep fluxes had units of <tt>kg/s</tt>.)  Therefore, when using output from the GEOS-Chem v10-01 Rn-Pb-Be simulation, make sure to adjust your data analysis programs to expect dry deposition fluxes in <tt>molec/cm2/s</tt>.'''</span>
 
#*Also note: For the Rn-Pb-Be simulation, <tt>molec/cm2/s</tt> really means <tt>atoms/cm2/s</tt>.  GEOS-Chem uses the same unit string <tt>molec/cm2/s</tt> regardless of whether a species is an element or a molecule.
 
 
--[[User:Bmy|Bob Y.]] ([[User talk:Bmy|talk]]) 20:34, 15 June 2015 (UTC)
 
 
== Non-local PBL mixing ==
 
 
=== GEOS-Chem v9-02 ===
 
 
<span style="color:green">'''''This update was tested in the 1-month benchmark simulation [[GEOS-Chem_v9-02_benchmark_history#v9-02o|v9-02o]] and approved on 03 Sep 2013.'''''</span>
 
 
Capability to use the [[Boundary_layer_mixing#VDIFF|non-local PBL mixing scheme]] was added in [[GEOS-Chem v9-02]]. Code updates were provided by [mailto:jlin5@pku.edu.cn Jintai Lin].
 
 
Karen Yu evaluated the non-local PBL mixing scheme in the Rn-Pb-Be simulation using [[GEOS-5]] and [[GEOS-FP]] met fields. Please see [http://wiki.seas.harvard.edu/geos-chem/images/RnPbBe_nonlocalPBL.pdf these plots] comparing the simulation with and without the non-local PBL mixing scheme.
 
 
--[[User:Bmy|Bob Yantosca]] ([[User talk:Bmy|talk]]) 16:43, 8 January 2016 (UTC)
 
 
=== GEOS-Chem v9-01-03 and earlier ===
 
 
Helen Amos discovered that the Rn-Pb-Be simulation was not compatible with non-local PBL mixing. In [[GEOS-Chem v9-01-03]] and earlier, You must use the [[Boundary_layer_mixing#TURBDAY|TURBDAY PBL mixing scheme]]. In the Chemistry Menu of input.geos:
 
 
Turn on PBL Mixing?    : T
 
  => Use non-local PBL?  : F
 
 
--[[User:Melissa Payer|Melissa Sulprizio]] 17:56, 5 August 2013 (EDT)
 
 
== Validation ==
 
 
The information was computed from 1-year Rn-Pb-Be benchmark simulations.
 
 
=== 1-year benchmark simulations ===
 
 
==== Benchmark plots ====
 
 
{| border=1 cellspacing=0 cellpadding=5
 
|- bgcolor="#CCCCCC"
 
!width="100px"|Version
 
!width="900px"|Link
 
|-
 
|'''[[GEOS-Chem v9-01-02|v9-01-02]]<br>w/ GEOS-5'''
 
|<tt>http://wiki.seas.harvard.edu/geos-chem/index.php/Rn-Pb-Be_simulation#Comparison_plots</tt>
 
|-
 
|'''[[GEOS-Chem v9-01-03 benchmark history#v9-01-03e_2|v9-01-03e]]<br>w/ GEOS-5'''
 
|<tt>http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v9-01-03/v9-01-03e/geos5/2005/RnPbBe/output/pdf/</tt>
 
|-
 
|'''[[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]]<br>w/ GEOS-5'''
 
|<tt>http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v9-02/v9-02r/geos5/RnPbBe/output/pdf/</tt>
 
|-
 
|'''[[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]]<br>w/ GEOS-FP'''
 
|<tt>http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v9-02/v9-02r/geosfp/RnPbBe/output/pdf/</tt>
 
|-
 
|'''[[GEOS-Chem_v10-01 benchmark_history#v10-01-public-release|v10-01]]<br>w/ GEOS-FP'''
 
|<tt>http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v10-01/v10-01-public-release/RnPbBe/output/</tt>
 
|-
 
|'''[[GEOS-Chem_v11-01 benchmark_history#v11-01b|v11-01b]]<br>w/ GEOS-FP'''
 
|<tt>http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01b/RnPbBe/output/</tt>
 
|-
 
|'''[[GEOS-Chem_v11-01 benchmark_history#v11-01d|v11-01d]]<br>w/ GEOS-FP'''
 
|<tt>http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01d/RnPbBe/output/</tt>
 
 
|}
 
|}
 
--[[User:Melissa Payer|Melissa Sulprizio]] ([[User talk:Melissa Payer|talk]]) 20:22, 30 October 2015 (UTC)
 
 
==== Budget of Pb210 ====
 
 
In this table we plot the budgets of Pb<sup>210</sup> obtained from 1-year benchmark simulations at 4&deg; x 5&deg; resolution done with various GEOS-Chem versions. 
 
 
{| border=1 cellspacing=0 cellpadding=5
 
|- bgcolor="#CCCCCC"
 
!width="75px" rowspan="3"|Version
 
!width="75px" rowspan="3"|Met Field
 
!width="75px" rowspan="3"|Year
 
!width="100px" rowspan="3"|Tropospheric burden [g]
 
!width="100px" rowspan="3"|Tropospheric lifetime against deposition [days]
 
!width="150px" colspan="2"|Sources [g day -1]
 
!width="375px" colspan="5"|Sinks [g day-1]
 
 
|-bgcolor="#CCCCCC"
 
!width="75px" rowspan="2"|From Stratosphere
 
!width="75px" rowspan="2"|From Troposphere
 
!width="75px" rowspan="2"|Dry Deposition
 
!width="225px" colspan="3"|Wet Deposition
 
!width="75px" rowspan="2"|Radioactive decay
 
 
|-bgcolor="#CCCCCC"
 
!width="100px"|Total
 
!width="100px"|Stratiform
 
!width="100px"|Convective
 
 
|-
 
|[[GEOS-Chem v8-03-02|v8-03-02]]
 
|GEOS-5
 
|2005
 
|298.318
 
|9.01288
 
|0.129642
 
|32.9831
 
|3.21013
 
|29.8775
 
|21.3283
 
|8.54923
 
|0.0266710
 
 
|-
 
|[[GEOS-Chem v9-01-01|v9-01-01]]
 
|GEOS-5
 
|2005
 
|316.253
 
|9.55568
 
|0.129852
 
|32.9831
 
|3.66397
 
|29.4223
 
|19.4090
 
|10.0134
 
|0.0251665
 
 
|-
 
|[[GEOS-Chem v9-01-02|v9-01-02]]
 
|GEOS-5
 
|2005
 
|317.884
 
|9.60957
 
|0.121441
 
|32.9831
 
|3.49208
 
|29.5857
 
|19.5148
 
|10.0709
 
|0.0268078
 
 
|-
 
|[[GEOS-Chem v9-01-03 benchmark history#v9-01-03e_2|v9-01-03e]]
 
|GEOS-5
 
|2005
 
|314.790
 
|9.51050
 
|0.128670
 
|32.9831
 
|3.48612
 
|29.5991
 
|20.8285
 
|8.77061
 
|0.0265495
 
 
|-
 
|[[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]]
 
|GEOS-5
 
|2012/2013
 
|305.699
 
|9.25835
 
|0.419521
 
|32.6109
 
|3.42747
 
|29.5772
 
|20.2059
 
|9.37127
 
|0.0257354
 
 
|-
 
|[[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]]
 
|GEOS-FP
 
|2012/2013
 
|247.630
 
|7.71356
 
|0.143133
 
|31.9904
 
|3.15887
 
|28.9538
 
|22.5351
 
|6.41867
 
|0.0208565
 
 
|-
 
|[[GEOS-Chem_v10-01 benchmark_history#v10-01-public-release|v10-01]]
 
|GEOS-FP
 
|2013
 
|250.912
 
|7.77516
 
|0.0832825
 
|32.2152
 
|3.51910
 
|28.7582
 
|22.0207
 
|6.73749
 
|0.0211769
 
 
|-
 
|[[GEOS-Chem_v11-01 benchmark_history#v11-01b|v11-01b]]
 
|GEOS-FP
 
|2013
 
|212.655
 
|6.60214
 
|0.228550
 
|31.9528
 
|3.49478
 
|28.6686
 
|22.0420
 
|6.62657
 
|0.0179612
 
 
|-
 
|[[GEOS-Chem_v11-01 benchmark_history#v11-01d|v11-01d]]
 
|GEOS-FP
 
|2013
 
|210.371
 
|6.54296
 
|0.225956
 
|31.9538
 
|3.41587
 
|28.7451
 
|21.9070
 
|6.83813
 
|0.0177696
 
 
|}
 
 
NOTES:
 
*The simulations that utilized GEOS-5 met fields were done for year 2005, with a 4-year spinup. (Computed by [mailto:hongyu.liu-1@nasa.gov Hongyu Liu])
 
*The benchmark simulations for [[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]] were done for June 2012&ndash;May 2013, with a 2-month spinup. This was due to data availability of the [[GEOS-FP]] met fields at the time of the simulation. (Completed by [mailto:kyu@seas.harvard.edu Karen Yu])
 
*The simulations for [[GEOS-Chem v10-01]] and later versions utilized GEOS-FP met fields for the year 2013, with a 4-year spinup. (Completed by the [[GEOS-Chem Support Team]])
 
*'''''<span style="color:darkorange">Hongyu Liu and Bo Zhang are investigating the low Pb tropospheric lifetime against deposition observed in v11-01b using GEOS-FP. A quick fix was tested in v11-01d, but subsequently removed because of the high impact on aerosols. For more information, see [[Wet_deposition#Low_tropospheric_210Pb_lifetime_against_deposition_in_v11-01b|this discussion on the ''Wet deposition'' wiki page]].</span>
 
 
--[[User:Melissa Payer|Melissa Sulprizio]] ([[User talk:Melissa Payer|talk]]) 15:55, 4 December 2015 (UTC)
 
 
==== Budget of Be7 ====
 
 
In this table we plot the budgets of Be<sup>7</sup> obtained from 1-year benchmark simulations at 4&deg; x 5&deg; resolution done with various GEOS-Chem versions.
 
 
{| border=1 cellspacing=0 cellpadding=5
 
|- bgcolor="#CCCCCC"
 
!width="150px" rowspan="3"|Version
 
!width="75px" rowspan="3"|Met Field
 
!width="75px" rowspan="3"|Year
 
!width="100px" rowspan="3"|Tropospheric burden [g]
 
!width="100px" rowspan="3"|Tropospheric lifetime against deposition [days]
 
!width="150px" colspan="2"|Sources [g day -1]
 
!width="375px" colspan="5"|Sinks [g day-1]
 
 
|-bgcolor="#CCCCCC"
 
!width="75px" rowspan="2"|From Stratosphere
 
!width="75px" rowspan="2"|From Troposphere
 
!width="75px" rowspan="2"|Dry Deposition
 
!width="225px" colspan="3"|Wet Deposition
 
!width="75px" rowspan="2"|Radioactive decay
 
 
|-bgcolor="#CCCCCC"
 
!width="75px"|Total
 
!width="75px"|Stratiform
 
!width="75px"|Convective
 
 
|-
 
|[[GEOS-Chem v8-03-02|v8-03-02]]
 
|GEOS-5
 
|2005
 
|4.31961
 
|33.9930
 
|0.0504585
 
|0.132552
 
|0.00808056
 
|0.118666
 
|0.0846774
 
|0.0339885
 
|0.0562636
 
 
|-
 
|[[GEOS-Chem v9-01-01|v9-01-01]]
 
|GEOS-5
 
|2005
 
|4.39407
 
|34.8514
 
|0.0504328
 
|0.132552
 
|0.00969345
 
|0.116060
 
|0.0767926
 
|0.0392671
 
|0.0572312
 
 
|-
 
|[[GEOS-Chem v9-01-02|v9-01-02]]
 
|GEOS-5
 
|2005
 
|4.39653
 
|34.8814
 
|0.0504253
 
|0.132552
 
|0.00936374
 
|0.116350
 
|0.0769681
 
|0.0393817
 
|0.0572633
 
 
|-
 
|[[GEOS-Chem v9-01-03 benchmark history#v9-01-03e_2|v9-01-03e]]
 
|GEOS-5
 
|2005
 
|4.37787
 
|34.6750
 
|0.0504472
 
|0.132552
 
|0.00882144
 
|0.117156
 
|0.0858211
 
|0.0393817
 
|0.0570217
 
 
|-
 
|[[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]]
 
|GEOS-5
 
|2012/2013
 
|3.49564
 
|27.5376
 
|0.0674867
 
|0.104750
 
|0.00881422
 
|0.117906
 
|0.0844566
 
|0.0334494
 
|0.0455165
 
 
|-
 
|[[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]]
 
|GEOS-FP
 
|2012/2013
 
|3.41039
 
|25.9787
 
|0.0630964
 
|0.112349
 
|0.00782526
 
|0.123206
 
|0.1093560
 
|0.0138500
 
|0.0444134
 
 
|-
 
|[[GEOS-Chem_v10-01 benchmark_history#v10-01-public-release|v10-01]]
 
|GEOS-FP
 
|2013
 
|3.98942
 
|30.1194
 
|0.0512072
 
|0.132977
 
|0.00794288
 
|0.124298
 
|0.1101450
 
|0.0141529
 
|0.0519433
 
 
|-
 
|[[GEOS-Chem_v11-01 benchmark_history#v11-01b|v11-01b]]
 
|GEOS-FP
 
|2013
 
|3.33530
 
|23.3408
 
|0.0530463
 
|0.132914
 
|0.00698390
 
|0.135539
 
|0.1228950
 
|0.0126441
 
|0.0434378
 
 
|-
 
|[[GEOS-Chem_v11-01 benchmark_history#v11-01d|v11-01d]]
 
|GEOS-FP
 
|2013
 
|3.32564
 
|23.2523
 
|0.0530363
 
|0.132914
 
|0.00664940
 
|0.135989
 
|0.122347
 
|0.0136424
 
|0.0433123
 
 
|}
 
 
NOTES:
 
*The simulations that utilized GEOS-5 met fields were done for year 2005, with a 4-year spinup. (Computed by [mailto:hongyu.liu-1@nasa.gov Hongyu Liu])
 
*The benchmark simulations for [[GEOS-Chem v9-02 benchmark history#v9-02r|v9-02r]] were done for June 2012&ndash;May 2013, with a 2-month spinup. This was due to data availability of the [[GEOS-FP]] met fields at the time of the simulation. (Completed by [mailto:kyu@seas.harvard.edu Karen Yu])
 
*The simulations for [[GEOS-Chem v10-01]] and later versions utilized GEOS-FP met fields for the year 2013, with a 4-year spinup. (Completed by the [[GEOS-Chem Support Team]])
 
 
--[[User:Melissa Payer|Melissa Sulprizio]] ([[User talk:Melissa Payer|talk]]) 15:55, 4 December 2015 (UTC)
 
 
=== GEOS-5 vs. MERRA ===
 
 
As demonstrated by Liu et al. (2001), the Rn-Pb-Be simulation is a valuable tool for testing aerosol wet scavenging in the model. Here the Rn-Pb-Be simulation is used to benchmark the differences between several configurations for the current implementation of aerosol wet scavenging in v9-01-02.
 
 
[mailto:hamos@fas.harvard.edu Helen Amos] ran 4 different 1-year Rn-Pb-Be simulations to look at how Pb<sup>210</sup> wet deposition is affected by [[GEOS-5]] and [[MERRA]] meteorology:
 
 
<blockquote>
 
;'''Run 1: GEOS-5 std''': Simulation with the standard [[GEOS-Chem v9-01-02]] code, using with GEOS-5 met fields
 
;'''Run 2: MERRA std''': Simulation with the standard GEOS-Chem v9-01-02 code, using with MERRA met fields.  This simulation is intended to give the user a sense of the differences to expect between using MERRA and GEOS-5 meteorological fields.
 
;'''Run 3: MERRA met GEOS-5 wet dep''': This simulation was run using GEOS-Chem v9-01-02 with MERRA meteorological fields and the GEOS-5 wet deposition algorithms (in <tt>wetscav_mod.F</tt> and <tt>convection_mod.F</tt>). Additional fields were archived for MERRA that were not archived for GEOS-5. These additional fields for MERRA were used to update the wet scavenging algorithms (e.g. precipitation production in MAKE_QQ) in v9-01-01.  This simulation is intended to discriminate between the effects of (a) meteorological fields and (b) changes made to the wet deposition algorithms for MERRA. 
 
;'''Run 4: GEOS-5 w/ Wang et al. (2011) aerosol washout''': This simulation was run using v9-01-02 with GEOS-5 fields and aerosol washout updated according to Wang et al. (2011, ACPD). This simulation is intended as a preview for what to expect when the Wang et al. (2011) updates go into the standard code in v9-01-03.
 
</blockquote>
 
 
All simulations were performed using [[GEOS-Chem v9-01-02]] at 4&deg; x 5&deg; resolution for the year 2009.
 
 
==== Comparison plots ====
 
 
Helen Amos also prepared the following comparison plots from these simulations.  All results shown are for [[GEOS-Chem v9-01-02]] at 4&deg; x 5&deg; resolution for the year 2009.  Monthly averages for January and July plotted separately.
 
 
{| border=1 cellspacing=0 cellpadding=5
 
|-bgcolor="#cccccc"
 
!Comparison
 
!width="75px"|
 
!width="75px"|
 
|-
 
|GEOS-5 standard simulation (Run 1) vs. MERRA standard simulation (Run 2)
 
|[[Media:f1_f2_jan_small.png|January]]
 
|[[Media:f1_f2_jul_small.png|July]]
 
|-
 
|GEOS-5 standard simulation (Run 1) vs. MERRA simulation w/ GEOS-5 wetdep algorithms (Run 3)
 
|[[Media:f1_f3_jan_small.png|January]]
 
|[[Media:f1_f3_jul_small.png|July]]
 
|-
 
|GEOS-5 standard simulation (Run 1) vs. GEOS-5 simulation w/ Wang et al (2011) aerosol washout (Run 4)
 
|[[Media:f1_f4_jan_small.png|January]]
 
|[[Media:f1_f4_jul_small.png|July]]
 
|}
 
 
--[[User:Bmy|Bob Y.]] 13:37, 29 November 2011 (EST)
 
 
==== Comparison budgets ====
 
 
Helen Amos also prepared the budgets from each of her 4 simulations.  These are compared to the original Rn-Pb-Be simulation as described in Liu et al. (2001).
 
 
{| border=1 cellspacing=0 cellpadding=5
 
|- bgcolor="#CCCCCC"
 
!width="300px" rowspan="3"|Version
 
!width="100px" rowspan="3"|Tropospheric burden [g]
 
!width="100px" rowspan="3"|Tropospheric lifetime against deposition [days]
 
!width="75px" colspan="1"|Sources [g day -1]
 
!width="375px" colspan="5"|Sinks [g day-1]
 
 
|-bgcolor="#CCCCCC"
 
!width="75px" rowspan="2"|Strat + Trop
 
!width="75px" rowspan="2"|Dry Deposition
 
!width="150px" colspan="2"|Wet Deposition
 
!width="75px" rowspan="2"|Radioactive decay
 
 
|-bgcolor="#CCCCCC"
 
 
!width="75px"|Stratiform
 
!width="75px"|Convective
 
 
|-
 
|Liu et al. (2001)
 
|299
 
|9
 
|34
 
|3.8
 
|21
 
|9.6
 
|0.03
 
 
|-
 
|'''Run 1'''<br>v9-01-02 w/ GEOS-5 std
 
|324.42
 
|9.80
 
|33.11
 
|3.37
 
|18.57
 
|11.14
 
|0.03
 
 
|-
 
|'''Run 2'''<br>v9-01-02 w/ MERRA std
 
|299.74
 
|9.05
 
|33.13
 
|3.37
 
|19.22
 
|10.54
 
|0.03
 
 
|-
 
|'''Run 3'''<br>v9-01-02 w/ MERRA met + GEOS-5 wetdep
 
|334.35
 
|9.93
 
|33.68
 
|3.37
 
|18.93
 
|11.37
 
|0.00
 
 
|-
 
|'''Run 4'''<br>v9-01-02 w/ GEOS-5 met + Wang washout**
 
|339.11
 
|10.26
 
|33.11
 
|3.68
 
|17.17
 
|12.21
 
|0.03
 
 
|}
 
 
--[[User:Bmy|Bob Y.]] 13:57, 29 November 2011 (EST)
 
 
--[[User:Helen Amos|Helen Amos]] 17:56, 12 September 2012 (EST), the labels for "convective" and "stratiform" were switched. Error corrected now. Thanks to Patrick Kim for pointing it out!
 
 
<nowiki>**</nowiki>Note: In Run 4, a condensed water content value of 1.5d-6 cm<sup>3</sup> H20/cm<sup>3</sup> air was used in the calculation of F' in <tt>wetscav_mod.F</tt>. Qiaoqiao Wang updated this value to 1.0d-6 cm<sup>3</sup> H20/cm<sup>3</sup> as described in [http://acmg.seas.harvard.edu/publications/wang_qiaoqiao2011.pdf Wang et al. <nowiki>[2011]</nowiki>]. The use of 1.0d-6 increases the fraction of precipitating area, resulting in a slightly shorter lifetime of Pb210, as seen in the [[Rn-Pb-Be_simulation#Budget_of_Pb210_from_1-year_benchmark_simulations|budget of Pb210]] from the 1-year Rn-Pb-Be benchmark simulation for [[GEOS-Chem_v9-01-03_benchmark_history#v9-01-03e_2|v9-01-03e]].
 
 
--[[User:Melissa Payer|Melissa Sulprizio]] ([[User talk:Melissa Payer|talk]]) 15:55, 4 December 2015 (UTC)
 
  
 
== References ==
 
== References ==
  
#Liu, H., D. Jacob, I. Bey, and R.M. Yantosca, ''Constraints from 210Pb and 7Be on wet deposition and transport in a global three-dimensional chemical tracer model driven by assimilated meteorological fields'', <u>J. Geophys. Res</u>, '''106''', D11, 12,109-12,128, 2001.
+
#Liu, H., D. Jacob, I. Bey, and R.M. Yantosca, ''Constraints from <sup>210</sup>Pb and <sup>7</sup>Be on wet deposition and transport in a global three-dimensional chemical tracer model driven by assimilated meteorological fields'', <u>J. Geophys. Res</u>, '''106''', D11, 12109-12128, 2001.
#Jacob et al., ''Evaluation and intercomparison of global atmospheric transport models using Rn-222 and other short-lived tracers'', <u>J. Geophys. Res</u>, '''102''', 5953-5970, 1997.
+
#Jacob et al., ''Evaluation and intercomparison of global atmospheric transport models using <sup>222</sup>Rn and other short-lived tracers'', <u>J. Geophys. Res</u>, '''102''', 5953-5970, 1997.
#Koch, D. <u>J. Geophys. Res</u>, '''101''', D13, 18651, 1996.
+
#Koch, D.M., D.J. Jacob, and W.C. Graustein, ''Vertical transport of tropospheric aerosols as indicated by <sup>7</sup>Be and <sup>210</sup>Pb in a chemical tracer model'', <u>J. Geophys. Res</u>, '''101''', D13, 18651-18666, 1996.
#Lal, D., and B. Peters, ''Cosmic ray produced radioactivity on the Earth''. <u>Handbuch der Physik</u>, '''46/2''', 551-612, edited by K. Sitte, Springer-Verlag, New York, 1967.  
+
#Koch, D., and D. Rind, ''Beryllium 10/beryllium 7 as a tracer of stratospheric transport'', <u>J. Geophys. Res.</u>, '''103''', D4, 3907-3917, 1998.
 
+
#Lal, D., and B. Peters, ''Cosmic ray produced radioactivity on the Earth''. <u>Handbuch der Physik</u>, '''46/2''', 551-612, edited by K. Sitte, Springer-Verlag, New York, 1967.
== Previous issues that are now resolved ==
+
 
+
=== Incorrect Rn values caused by bug in convection_mod.f ===
+
 
+
[[GEOS-Chem_v8-03-02#TINY_parameter_in_convection_mod.f|The bug in convection_mod.f described here]] can cause incorrect values of Rn in [[GEOS-Chem v8-03-01]] and prior versions.  This was fixed in [[GEOS-Chem v8-03-02]].
+
 
+
--[[User:Bmy|Bob Y.]] 16:17, 19 May 2011 (EDT)
+
 
+
=== Bug for ND44 diagnostic in diag3.f ===
+
 
+
<span style="color:green">'''''NOTE: This bug was issued as a post-release patch ("v9-01-01-Patch-diags") in [[GEOS-Chem v9-01-01]] and was approved on 07 Jun 2011.'''''</span>
+
 
+
In the ND44 diagnostic section of <tt>diag3.f</tt>, the following lines are present twice (once for drydep fluxes and again for drydep velocities).  This is a special-case for some tracers in the Caltech isoprene scheme:
+
 
+
              ! Special case for tracers with several dry dep. tracers
+
              ! E.g. ISOPN: ISOPND and ISOPNB.
+
              ! We handle both tracers at the same time so we need to
+
              ! skip the second tracer. (ccc, 2/3/10)
+
              !IF ( MMB /= NN ) CYCLE
+
              IF ( MMB /= NN                .OR.
+
    &              DEPNAME( N ) == 'ISOPNB' .OR.
+
    &              DEPNAME( N ) == 'MVKN'       ) CYCLE
+
 
+
However, these lines will cause the drydep fluxes and velocities for Be7 to be skipped.  The fix is to bracket these lines with an IF statement so that they will only execute for a full-chemistry simulation:
+
 
+
            IF ( ITS_A_FULLCHEM_SIM() ) THEN
+
              ! Special case for tracers with several dry dep. tracers
+
              ! E.g. ISOPN: ISOPND and ISOPNB.
+
              ! We handle both tracers at the same time so we need to
+
              ! skip the second tracer. (ccc, 2/3/10)
+
              !IF ( MMB /= NN ) CYCLE
+
              IF ( MMB /= NN                .OR.
+
    &              DEPNAME( N ) == 'ISOPNB' .OR.
+
    &              DEPNAME( N ) == 'MVKN'      ) CYCLE
+
            ENDIF
+
 
+
--[[User:Bmy|Bob Y.]] 11:57, 7 July 2011 (EDT)
+
 
+
=== Out-of-bounds errors in ND01, ND02 diagnostics ===
+
 
+
<span style="color:green">'''''This issue was fixed in [[GEOS-Chem v9-01-02]], just prior to its release.'''''</span>
+
 
+
In <tt>RnPbBe_mod.F</tt>, the ND01 (Source of Rn, Pb, Be) and ND02 (Decay of Rn, Pb, Be) diagnostics had [[Common GEOS-Chem error messages#Array-out-of-bounds|array-out-of-bounds errors]] if you requested less than 47 levels. 
+
 
+
For example, if you specified these settings in your <tt>input.geos</tt> file (assuming a GEOS-5 or MERRA simulation  w/ 47 levels):
+
 
+
ND01: Rn/Pb/Be source  : 47  all
+
ND02: Rn/Pb/Be decay    : 47  all
+
 
+
then your run would work just fine.  However, if you tried this:
+
 
+
ND01: Rn/Pb/Be source  :  1  all
+
ND02: Rn/Pb/Be decay    :  1  all
+
 
+
then your run would crash.  In some instances, the error masked itself as an I/O error (i.e. "file not found").  This is because an out-of-bounds was probably corrupting the variables that were used to check if all of the data had been read from a particular met field file.
+
 
+
To prevent this from happening, we now test whether the L index is smaller or equal to LD01 (the vertical extent of the AD01 array) or LD02 (the vertical extent of the AD02 array).  We have now modified all of the IF statements where the ND01 or ND02 diagnostics are invoked. 
+
 
+
For example, we took the existing block of code:
+
 
+
      ! ND01 diag: 7Be emission [kg/s]
+
      IF ( ND01 > 0 ) THEN
+
        AD01(I,J,L,3) = AD01(I,J,L,3) + ( ADD_Be / DTSRCE )
+
      ENDIF
+
 
+
and add an additional test on L:
+
 
+
      ! ND01 diag: 7Be emission [kg/s]
+
      IF ( ND01 > 0 .and. L <= LD01 ) THEN
+
        AD01(I,J,L,3) = AD01(I,J,L,3) + ( ADD_Be / DTSRCE )
+
      ENDIF
+
 
+
etc.
+
 
+
We will add this fix into [[GEOS-Chem v9-01-02]], since it does not affect the full-chemistry simulation.
+
 
+
--[[User:Bmy|Bob Y.]] 11:08, 28 November 2011 (EST)
+
 
+
=== Missing drydep diagnostics caused by tracer name error  ===
+
 
+
<span style="color:green">'''''This update was tested in the 1-month benchmark simulation [[GEOS-Chem_v9-01-03_benchmark_history#v9-01-03g|v9-01-03g]] and approved on 27 Feb 2012.'''''</span>
+
 
+
Please use the following tracer names in <tt>input.geos</tt> when setting up a Rn-Pb-Be simulation:
+
 
+
%%% TRACER MENU %%%    :
+
Type of simulation      : 1
+
Number of Tracers      : 3                     
+
Tracer Entries -------> : TR#  Name  g/mole  Tracer Members; () = emitted
+
Tracer #1              :  1  Rn    222.0 
+
Tracer #2              :  2  Pb    210.0
+
Tracer #3              :  3  Be7      7.0
+
 
+
If you use alternate spellings for the Rn and Pb tracers, such as:
+
 
+
Tracer #1              :  1  Rn222  222.0 
+
Tracer #2              :  2  Pb210  210.0
+
 
+
Then this may cause the dry deposition fluxes and frequencies for Pb<sup>210</sup> not to be printed out.
+
 
+
A fix is forthcoming in [[GEOS-Chem v9-01-03]].
+
 
+
--[[User:Bmy|Bob Y.]] 11:57, 7 July 2011 (EDT)
+
 
+
== Outstanding issues ==
+
 
+
=== Typo in HEMCO extension module hcox_gc_RnPbBe_mod.F90 ===
+
 
+
<span style="color:darkorange">'''''This issue will be fixed in [[GEOS-Chem v11-01#v11-01f|v11-01f]].'''''</span>
+
 
+
'''''[[User:Mje|Mat Evans]] wrote:'''''
+
 
+
<blockquote>
+
We’ve just installed fort 16.0.1 (upgrading from 13.0.1).
+
 
+
A bug come up in the compilation of the code for <tt>HEMCO/Extensions/hcox_gc_RnPbBe_mod.F</tt> where there is essentially a data statement so that 54_hp wouldn’t compile as it was an integer but 54.0_hp would.
+
</blockquote>
+
 
+
In module <tt>HEMCO/Extensions/hcox_gc_RnPbBe_mod.F90</tt>, we have replaced the text in <span style="color:red">RED</span>:
+
 
+
    BESOU(:,22) = (/    25.5_hp,     26.5_hp,     32.0_hp,   40.5_hp,    &
+
                          <span style="color:red">54_hp</span>,    67.5_hp,    69.5_hp,    69.5_hp,    &
+
                        69.5_hp,    69.5_hp  /)
+
 
+
with the text in <span style="color:green">RED</span>:
+
  
    BESOU(:,22) = (/    25.5_hp,    26.5_hp,    32.0_hp,    40.5_hp,    &
 
                        <span style="color:green">54.0_hp</span>,    67.5_hp,    69.5_hp,    69.5_hp,    &
 
                        69.5_hp,    69.5_hp  /)
 
  
--[[User:Bmy|Bob Yantosca]] ([[User talk:Bmy|talk]]) 16:53, 8 January 2016 (UTC)
+
----
 +
'''''[[Tagged O3 simulation|Previous]] | [[Guide to GEOS-Chem simulations|Next]] | [[Guide to GEOS-Chem simulations]]'''''

Latest revision as of 16:08, 21 May 2024

Previous | Next | Guide to GEOS-Chem simulations

  1. Simulations using KPP-built mechanisms (carbon, fullchem, Hg)
  2. Aerosol-only simulation
  3. CH4 simulation
  4. CO2 simulation
  5. Metals simulation
  6. Hg simulation
  7. POPs simulation
  8. Tagged CO simulation
  9. Tagged O3 simulation
  10. TransportTracers simulation


This page contains information about the TransportTracers (formerly Rn-Pb-Be) simulation in GEOS-Chem.

Overview

The Rn-Pb-Be simulation in GEOS-Chem was based on that of the old Harvard/GISS CTM model. The current simulation follows Liu et al (2001).

In GEOS-Chem 12.2.0 the Rn-Pb-Be simulation was extended to include additional passive species for benchmarking purposes and for diagnosing transport in GEOS-Chem. At this time the simulation was renamed to the TransportTracer simulation.

In GEOS-Chem 14.2.0 the TransportTracers simulation was further modified so that species names and definitions are now consistent with GMAO's tracer gridded component (aka TR_GridComp). This will facilitate comparison of transport within GEOS-Chem, GCHP, and GEOS.

List of species

The transport tracers are summarized below.

Species name Description Source Sink Purpose
Rn222 Radon-222 isotope
  • Half-life of 3.83 days (Liu at al., 2001).
    • Decays into Pb210 according to the exponential law:
EXP( -ΔT * 2.097d-6 )
Used to evaluate convection over land and strat-trop exchange
Pb210 Lead-210 isotope
  • Radioactive decay from Rn222 according to the exponential law:
EXP( -ΔT * 2.097d-6 )
Where ΔT is the emission timestep in seconds.
  • Half-life of 22.3 years (Liu et al., 2001).
    • Decays according to the exponential law:
EXP( -ΔT * 9.725d-10 )
  • Wet deposition
  • Dry deposition
Used to evaluate wet scavenging and transport
Pb210s Lead-210 isotope stratospheric-source tracer
  • Same as Pb210 (restricted to the stratosphere)
  • Same as Pb210
Used to evaluate strat-trop exchange
Be7 Beryllium-7 isotope
  • Produced by cosmic rays as described in Lal and B. Peters, 1967
  • Plus the following modifications from Liu et al. (2001):
  1. Replace data at (0 hPa altitude, 70°S latitude) following Koch (1996):
    • old value = 3000 disintegrations/g air/s
    • new value = 1900 disintegrations/g air/s
  2. The original Lal & Peters data ended at 70°S
    • Copy the data values at 70°S to 80°S and 90°S at all levels
  • Half-life of 53.3 days (Liu et al., 2001).
    • Decays according to the exponential law:
EXP( -ΔT * 1.506d-7 )
  • Wet deposition
  • Dry deposition
Used to evaluate wet scavenging and strat-trop exchange
Be7s Beryllium-7 isotope stratospheric source tracer
  • Same as Be7 (restricted to the stratosphere)
  • Same as Be7
Used to evaluate strat-trop exchange
Be10 Beryllium-10 isotope
  • Be10 has an identical source distribution as Be7 following Koch and Rind (1998).
  • Half-life of 5.84e8 days (Koch and Rind, 1998).
    • Decays according to the exponential law:
EXP( -ΔT * 1.506d-7 )
  • Wet deposition
  • Dry deposition
Used to evaluate wet scavenging and strat-trop exchange
Be10s Beryllium-10 isotope stratospheric source tracer
  • Same as Be10 (restricted to the stratosphere)
  • Same as Be10
Used to evaluate strat-trop exchange
PassiveTracer Passive tracer with initial concentration of 100 ppb
  • None
  • None
Used to evaluate mass conservation in transport
SF6 Sulfur hexafluoride
  • Anthropogenic emissions from EDGAR v4.2
  • None
Used to evaluate inter-hemispheric transport of anthropogenic emissions
CH3I Methyl iodide
  • Emissions over the oceans of 1 molec/cm2/s
  • 5-day e-folding lifetime
Used to evaluate marine convection
CO_25 Anthropogenic CO 25-day tracer
  • Emissions from CEDS v2
  • 25-day e-folding lifetime
CO_50 Anthropogenic CO 50-day tracer
  • Emissions from CEDS v2
  • 50-day e-folding lifetime
e90 Constant burden 90-day tracer
  • Emitted globally at the surface such that the mixing ratio is maintained at 100 ppbv
  • 90-day e-folding lifetime
e90_n Constant burden Northern Hemisphere 90-day tracer
  • Emitted at the surface such that the mixing ratio is maintained at 100 ppbv. Emissions source is restricted to 40N - 90N.
  • 90-day e-folding lifetime
e90_s Constant burden Southern Hemisphere 90-day tracer
  • Emitted at the surface such that the mixing ratio is maintained at 100 ppbv. Emissions source is restricted to 90S - 40S.
  • 90-day e-folding lifetime
aoa Age of air uniform source tracer
  • Increases by a value of 1 each emissions timestep
  • Sink at the surface
Used for evaluating residual circulation and mixing
aoa_bl Age of air uniform source tracer with sink restricted to the boundary layer
  • Increases by a value of 1 each emissions timestep
  • Sink in the boundary layer
Used for evaluating residual circulation and mixing
aoa_nh Age of air uniform source tracer with sink restricted to a zone in the Northern Hemisphere
  • Increases by a value of 1 each emissions timestep
  • Sink at 30N - 50N
Used for evaluating residual circulation and mixing
nh_5 Northern Hemisphere 5-day tracer
  • Constant source of 100 ppbv at latitudes 30N - 50N
  • 5-day e-folding lifetime
nh_50 Northern Hemisphere 50-day tracer
  • Constant source of 100 ppbv at latitudes 30N - 50N
  • 50-day e-folding lifetime
st80_25 Stratospheric source 25-day tracer
  • Constant source of 200 ppbv above 80 hPa
  • 25-day e-folding lifetime

References

  1. Liu, H., D. Jacob, I. Bey, and R.M. Yantosca, Constraints from 210Pb and 7Be on wet deposition and transport in a global three-dimensional chemical tracer model driven by assimilated meteorological fields, J. Geophys. Res, 106, D11, 12109-12128, 2001.
  2. Jacob et al., Evaluation and intercomparison of global atmospheric transport models using 222Rn and other short-lived tracers, J. Geophys. Res, 102, 5953-5970, 1997.
  3. Koch, D.M., D.J. Jacob, and W.C. Graustein, Vertical transport of tropospheric aerosols as indicated by 7Be and 210Pb in a chemical tracer model, J. Geophys. Res, 101, D13, 18651-18666, 1996.
  4. Koch, D., and D. Rind, Beryllium 10/beryllium 7 as a tracer of stratospheric transport, J. Geophys. Res., 103, D4, 3907-3917, 1998.
  5. Lal, D., and B. Peters, Cosmic ray produced radioactivity on the Earth. Handbuch der Physik, 46/2, 551-612, edited by K. Sitte, Springer-Verlag, New York, 1967.



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