TransportTracers simulation

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1. Simulations using KPP-built mechanisms
2. Aerosol-only simulation
3. CH4 simulation
4. CO2 simulation
5. Hg simulation
6. POPs simulation
7. Tagged CO simulation
8. Tagged O3 simulation
9. TransportTracers simulation

This page contains information about the Radon-Lead-Beryllium (and optional passive species) 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 Bold 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	Emitted naturally from soils based on Zhang et al., 2021.	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): 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 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

1-year benchmark simulations

Benchmark overview

1-year Rn-Pb-Be benchmark simulations are completed at the request of the Transport Working Group or whenever an update is introduced into the code that will impact transport and/or wet deposition. Each of these benchmarks involve a 4-year spinup period, followed by the 1-year run used for evaluation.

Benchmark plots

Version	Link
12.8.0 w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/GC_12/12.8.0/
12.2.0 w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/GC_12/12.2.0/TransportTracers/output/
v11-02e w/ GEOS-FP (2016 met)	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-02/v11-02e/RnPbBePasv-Run2/NLPBL/output/
v11-02e w/ GEOS-FP (72 levels)	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-02/v11-02e/RnPbBePasv-Run1/NLPBL/output/
v11-02e w/ GEOS-FP (2013 met)	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-02/v11-02e/RnPbBePasv-Run0/NLPBL/output/
v11-02b w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-02/v11-02b/RnPbBePasv/RnPbBePasv_VDIFF/output/
v11-01i w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01i/RnPbBePasv/RnPbBePasv_VDIFF/output/
v11-01h w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01h/RnPbBePasv/RnPbBePasv_VDIFF/output/
v11-01f w/ MERRA-2	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01f/MERRA2/RnPbBe/RnPbBePasv_VDIFF/output/
v11-01f w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01f/GEOSFP/RnPbBe/RnPbBePasv_VDIFF/output/
v11-01d w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01d/RnPbBe/RnPbBePasv_VDIFF/output/
v11-01b w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v11-01/v11-01b/RnPbBe/output/
v10-01 w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v10-01/v10-01-public-release/RnPbBe/output/
v9-02r w/ GEOS-FP	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v9-02/v9-02r/geosfp/RnPbBe/output/pdf/
v9-02r w/ GEOS-5	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v9-02/v9-02r/geos5/RnPbBe/output/pdf/
v9-01-03e w/ GEOS-5	http://ftp.as.harvard.edu/gcgrid/geos-chem/1yr_benchmarks/v9-01-03/v9-01-03e/geos5/2005/RnPbBe/output/pdf/
v9-01-02 w/ GEOS-5	http://wiki.seas.harvard.edu/geos-chem/index.php/Rn-Pb-Be_simulation#Comparison_plots

Budget of Pb210

In this table we plot the budgets of Pb²¹⁰ obtained from 1-year benchmark simulations at 4° x 5° resolution done with various GEOS-Chem versions.

Version	Met Field	Year	Tropospheric burden [g]	Tropospheric lifetime against deposition [days]	Sources [g day -1]		Sinks [g day-1]
					From Stratosphere	From Troposphere	Dry Deposition	Wet Deposition			Radioactive decay
								Total	Stratiform	Convective
12.8.0 (with Luo2019 wetdep)	GEOS-FP (72L)	2016	105.1827	3.2461	0.2690	32.1142	2.3068	30.0303	25.4236	4.6067	0.0088608
12.8.0	GEOS-FP (72L)	2016	211.6465	6.5363	0.2690	32.1142	3.9521	28.4142	19.9437	8.4705	0.0178018
12.2.0	GEOS-FP (72L)	2016	218.330	6.71344	0.236801	32.2602	3.95678	28.5218	20.0439	8.47787	0.0183735
v11-02e	GEOS-FP (72L)	2016	217.941	6.71192	0.224000	32.2206	3.94971	28.4770	20.0147	8.46232	0.0183407
v11-02e	GEOS-FP (72L)	2013	229.338	7.10583	0.219856	32.0661	3.90212	28.3646	19.9166	8.44793	0.0192987
v11-02e	GEOS-FP	2013	229.338	7.10583	0.219864	32.0661	3.90212	28.3646	19.9166	8.44793	0.0192987
v11-02b	GEOS-FP	2013	229.061	7.09725	0.219669	32.0661	3.93661	28.3299	19.8931	8.43679	0.0192754
v11-01i	GEOS-FP	2013	229.335	7.10581	0.219894	32.0656	3.90206	28.3642	19.9163	8.44786	0.0192984
v11-01h	GEOS-FP	2013	205.551	6.37603	0.200768	32.0656	3.32588	28.9232	22.2968	6.62642	0.0173020
v11-01f	MERRA-2	2013	199.426	6.20202	0.237400	31.9437	3.26365	28.9007	21.7525	7.14814	0.0167875
v11-01f	GEOS-FP	2013	204.931	6.37746	0.225323	31.9356	3.32210	28.8216	22.2060	6.61553	0.0172499
v11-01d	GEOS-FP	2013	210.371	6.54296	0.225956	31.9538	3.41587	28.7451	21.9070	6.83813	0.0177696
v11-01b	GEOS-FP	2013	212.655	6.60214	0.228550	31.9528	3.49478	28.6686	22.0420	6.62657	0.0179612
v10-01	GEOS-FP	2013	250.912	7.77516	0.0832825	32.2152	3.51910	28.7582	22.0207	6.73749	0.0211769
v9-02r	GEOS-FP	2012/2013	247.630	7.71356	0.143133	31.9904	3.15887	28.9538	22.5351	6.41867	0.0208565
v9-02r	GEOS-5	2012/2013	305.699	9.25835	0.419521	32.6109	3.42747	29.5772	20.2059	9.37127	0.0257354
v9-01-03e	GEOS-5	2005	314.790	9.51050	0.128670	32.9831	3.48612	29.5991	20.8285	8.77061	0.0265495
v9-01-02	GEOS-5	2005	317.884	9.60957	0.121441	32.9831	3.49208	29.5857	19.5148	10.0709	0.0268078
v9-01-01	GEOS-5	2005	316.253	9.55568	0.129852	32.9831	3.66397	29.4223	19.4090	10.0134	0.0251665
v8-03-02	GEOS-5	2005	298.318	9.01288	0.129642	32.9831	3.21013	29.8775	21.3283	8.54923	0.0266710

NOTES:

• Bolded text denotes change in meteorology product and/or meteorology year.
• The simulations that utilized GEOS-5 met fields were done for year 2005, with a 4-year spinup. (Computed by Hongyu Liu)
• The benchmark simulations for v9-02r were done for June 2012–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 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. The results reported here are for simulations using the non-local PBL mixing (VDIFF) scheme. (Completed by the GEOS-Chem Support Team)
• The simulations for GEOS-Chem 12.2.0 and later versions utilized GEOS-FP met fields for the year 2016, with a 10-year spinup. The results reported here are for simulations using the non-local PBL mixing (VDIFF) scheme. (Completed by the GEOS-Chem Support Team)
• 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 this discussion on the Wet deposition wiki page.

Budget of Be7

In this table we plot the budgets of Be⁷ obtained from 1-year benchmark simulations at 4° x 5° resolution done with various GEOS-Chem versions.

Version	Met Field	Year	Tropospheric burden [g]	Tropospheric lifetime against deposition [days]	Sources [g day -1]		Sinks [g day-1]
					From Stratosphere	From Troposphere	Dry Deposition	Wet Deposition			Radioactive decay
								Total	Stratiform	Convective
12.8.0 (with Luo2019 wetdep)	GEOS-FP (72L)	2016	1.1882	9.5228	0.2882	0.1149	0.0052	0.1188	0.1029	0.0159	0.0154770
12.8.0	GEOS-FP (72L)	2016	2.8927	20.5842	0.2882	0.1149	0.0095	0.1305	0.1047	0.0258	0.0376572
12.2.0	GEOS-FP (72L)	2016	3.55540	24.5959	0.0541444	0.136303	0.00952537	0.134645	0.108871	0.0257736	0.0462768
v11-02e	GEOS-FP (72L)	2016	3.56036	24.6000	0.0543652	0.136303	0.00955045	0.134776	0.108970	0.0258063	0.0463413
v11-02e	GEOS-FP (72L)	2013	3.50286	24.9516	0.0529614	0.132687	0.0102709	0.129784	0.103733	0.0260514	0.0455928
v11-02e	GEOS-FP	2013	3.51047	24.9816	0.0531919	0.132687	0.0102796	0.129907	0.103831	0.0260759	0.0456918
v11-02b	GEOS-FP	2013	3.51002	24.9773	0.0531920	0.132688	0.0103364	0.129856	0.103796	0.0260605	0.0456861
v11-01i	GEOS-FP	2013	3.51044	24.9815	0.0531920	0.132685	0.0102795	0.129907	0.103831	0.0260760	0.0456914
v11-01h	GEOS-FP	2013	3.27337	22.7988	0.0531059	0.132685	0.00626941	0.136914	0.124153	0.0127610	0.0426082
v11-01f	MERRA-2	2013	3.12435	21.2728	0.0538848	0.133202	0.00650753	0.139910	0.124784	0.0151255	0.0406699
v11-01f	GEOS-FP	2013	3.27720	22.8066	0.0531204	0.132842	0.00628201	0.137021	0.124239	0.0127822	0.0426591
v11-01d	GEOS-FP	2013	3.32564	23.2523	0.0530363	0.132914	0.00664940	0.135989	0.122347	0.0136424	0.0433123
v11-01b	GEOS-FP	2013	3.33530	23.3408	0.0530463	0.132914	0.00698390	0.135539	0.1228950	0.0126441	0.0434378
v10-01	GEOS-FP	2013	3.98942	30.1194	0.0512072	0.132977	0.00794288	0.124298	0.1101450	0.0141529	0.0519433
v9-02r	GEOS-FP	2012/2013	3.41039	25.9787	0.0630964	0.112349	0.00782526	0.123206	0.1093560	0.0138500	0.0444134
v9-02r	GEOS-5	2012/2013	3.49564	27.5376	0.0674867	0.104750	0.00881422	0.117906	0.0844566	0.0334494	0.0455165
v9-01-03e	GEOS-5	2005	4.37787	34.6750	0.0504472	0.132552	0.00882144	0.117156	0.0858211	0.0393817	0.0570217
v9-01-02	GEOS-5	2005	4.39653	34.8814	0.0504253	0.132552	0.00936374	0.116350	0.0769681	0.0393817	0.0572633
v9-01-01	GEOS-5	2005	4.39407	34.8514	0.0504328	0.132552	0.00969345	0.116060	0.0767926	0.0392671	0.0572312
v8-03-02	GEOS-5	2005	4.31961	33.9930	0.0504585	0.132552	0.00808056	0.118666	0.0846774	0.0339885	0.0562636

NOTES:

• Bolded text denotes change in meteorology product and/or meteorology year.
• The simulations that utilized GEOS-5 met fields were done for year 2005, with a 4-year spinup. (Computed by Hongyu Liu)
• The benchmark simulations for v9-02r were done for June 2012–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 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. The results reported here are for simulations using the non-local PBL mixing (VDIFF) scheme. (Completed by the GEOS-Chem Support Team)
• The simulations for GEOS-Chem 12.2.0 and later versions utilized GEOS-FP met fields for the year 2016, with a 10-year spinup. The results reported here are for simulations using the non-local PBL mixing (VDIFF) scheme. (Completed by the GEOS-Chem Support Team)

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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