Mean OH concentration

On this page we track the evolution of the mean OH concentration in GEOS-Chem. This value is an indicator of how "hot" the chemistry is. Please also see the related topic about the methyl chloroform lifetime in GEOS-Chem.

Evolution of mean OH in GEOS-Chem

Plot of mean OH evolution

Here is a plot of the mean OH concentration from GEOS-Chem 1-year benchmark simulations through version 12.8.0 (released 04 May 2020). The mean OH is an indicator how the chemistry mechanism is performing. Typical values are 10–12 x 10⁵ molecules cm^-1.

--Melissa Sulprizio (talk) 02:17, 13 August 2023 (UTC)

Mean OH in GEOS-Chem 12

The following table chronicles the evolution of the mean OH value from several different GEOS-Chem simulations. All benchmark simulations were conducted at 4° x 5° resolution unless noted otherwise.

Benchmark	Met Fields & Year	Mean OH [105 molec cm-3]	Change from prev. version [105 molec cm-3]	Important updates in this benchmark simulation	References
12.8.0	GEOS-FP 2016	10.613	+0.108 (+1.02%)	Updates introduced in 12.8.0: Isoprene chemistry Wet deposition parameterization Ozone deposition to the ocean Use online DustDead, MEGAN, SeaSalt, and SoilNOx emissions for benchmark simulations Updates introduced in 12.7.0: Small alkyl nitrate chemistry Methanol as part of standard chemical mechanism Update to Yuan processed MODIS LAI product (covering years 2005-2016) Latitudinally and monthly resolved fixed surface concentrations for long-lived organohalogen species (1750-2014) and methane Fix incorrect uptake coefficient for N2O5 in heterogeneous chemistry
12.6.0	GEOS-FP 2016	10.505	-0.797 (-7.05%)	Updates introduced in 12.6.0: Combined heterogeneous chemistry updates HNO3 cold-temperature deposition Quick fix for aerosol pH calculation when dry Remove isoprene in VBS (leaving aqueous) Updated aerosol hygroscopicity and optics Add EDGAR BCPI and BCPO emissions for remaining sectors to DICE-Africa Updates introduced in 12.5.0: Retire obsolete emission inventories Updated offline biogenic emissions generated with GEOS-Chem 12.3.0 Updated volcano emissions to include eruptive emissions through April 2018 Scale DICE-Africa emissions to address errors in inventory Bug fix for C3H8 anthropogenic emissions Separate anthropogenic PM2.5 dust source from the DustDead extension Corrections for CFCs in the chemistry mechanism Fix typo in CLD_PARAMS routine in gckpp_HetRates.F90 Bug fix: make sure stratospheric BrY concentrations are read properly each month
12.4.0	GEOS-FP 2016	11.302	-.346 (-2.97%)	Updates introduced in 12.4.0: Grid-independent lightning NOx emissions (3-hourly) Grid-independent biogenic emissions (hourly) Grid-independent sea salt emissions (hourly) Grid-independent soil NOx emissions (hourly) Updated volcano emissions (1978-2019) Updates introduced in 12.3.0: Update ISORROPIA from v2.0 to v2.2, in order to remove persistent noise in output Updated PFT file for MEGAN Read in and regrid existing MODIS LAI and OLSON data via HEMCO Updates introduced in 12.2.0: Retire BRAVO emissions and use CEDS for Mexico instead Update mask file applied to NEI2011 emissions Updates introduced in 12.1.0: Budget diagnostics Anthropogenic PM2.5 dust source GEOS-Chem restart file updates Add missing RCO sector to CEDS emissions entries Include CEDS ship emissions as default global ship emissions inventory Allow for SZA to 98 degrees when getting photolysis rates
12.0.0	GEOS-FP 2016	11.648	+0.116 (+0.101%)	Updates introduced in 12.0.0 Turn off TRASH emissions by default to avoid double counting Add entries to HEMCO_Config.rc for SOAP and pFe in CEDS inventory Bug fix for liquid water content in gckpp_HetRates.F90 Bug fix for CH4 boundary conditions Fixed typo in call to GAMMA_HOBr_AER Correct issues when specifying DICE-Africa emissions: Avoid double-counting between DICE-Africa and other inventories Use unique names for DICE-Africa entries in the HEMCO_Config.rc file Add missing Criegee intermediate reaction Bug fix for ARCTAS_SHIP in HEMCO_Config.rc files Bug fix in FlexChem: do not zero out ACTA, EOH, HCOOH concentrations Add GFED4.1 data for 2015 and 2016; Use GFED4.1 2016 in benchmarks

Mean OH in GEOS-Chem v11

The following table chronicles the evolution of the mean OH value from several different GEOS-Chem simulations. All benchmark simulations were conducted at 4° x 5° resolution unless noted otherwise.

Benchmark	Met Fields & Year	Mean OH [105 molec cm-3]	Change from prev. version [105 molec cm-3]	Important updates in this benchmark simulation	References
v11-02f-Run0	GEOS-FP 2016	11.532	-0.009 (-0.077%)	Updates introduced in v11-02f: Update HEMCO from v2.1.001 to v2.1.005 Use global 0.25x0.25 files for MEGAN input and MODIS LAI Update lightning BETA values and OTD/LIS files for consistency with latest met fields CEDS global anthropogenic emissions (1950-2014) EDGAR v4.3.1 emissions Historical Canadian emissions Global ethane emissions Inefficient combustion emissions in Africa (DICE-Africa inventory) Trash burning emissions Update GFED4 emission factors Retire GFED3 biomass burning emissions Ammonia emissions from Arctic seabirds Restore use of prod/loss rates from GMI in the mesosphere for UCX-based simulations Fix bug in units of UCX prod/loss rates Add fix for UCX mesospheric NOy routine Fix Henry's Law parameters for HCl Fix for N2O5 uptake Add fix for organic nitrate chemistry	GEOS-Chem v11-02
v11-02e-Run1	GEOS-FP 2016	11.541	-0.145 (-1.24%)	Same as v11-02e-Run0, but Use GEOS-FP 2016 meteorology instead of GEOS-FP 2013 meteorology	GEOS-Chem v11-02
v11-02e-Run0	GEOS-FP 2016	11.686	-0.171 (-1.44%)	Updates introduced in v11-02e: Monthly mean surface methane distributions UCX updates, including: Remove initial stratospheric 2D mixing ratio option UCX stratospheric water boundary condition update Remove UCX=y as compile switch and use Input_Opt%LUCX instead Use monthly mean stratospheric prod/loss rates from UCX simulation for all species Update density of BC to 1.8 and add absorption enhancement factor in input.geos Metal catalyzed oxidation of SO2 as a switch (on by default) SOA updates and bug fixes, including: Remove MONX from chemical mechanisms Add MTPO as a species in full-chemistry simulations Updating SOAP and SOAS entries in HEMCO to follow MTPA+LIMO+MTPO rather than MONX Use simple SOA in calculation of PM2.5, AOD, and aerosol mass by default Always use SOA formation from aqueous isoprene uptake (remove switch from input.geos) Fixes for isoprene SOA for consistency with Marais et al. (2016) Fix dust rainout settings to match BCPO Fixes in gckpp_HetRates.F90 for halogen chemistry *Add bug fix in sulfate_mod.F involving reorder IF statements for Fahey and Seinfeld decision algorithm Sync GEOS-FP files on Harvard ftp with files at Dalhousie	GEOS-Chem v11-02
v11-02d-Run2	GEOS-FP 2013	11.857	0.195 (1.672%)	Everything in v11-02d-Run0, plus: Now fixes a bug in CHEM_SO2 that caused too much sulfate production Fix bug impacting dust radius obtained in RDUST_ONLINE for UCX simulations Add fix for IPMN reactions contributing to high P(Ox) and L(Ox)	GEOS-Chem v11-02
v11-02d-Run0	GEOS-FP 2013	11.662	0.066 (0.569%)	Updates introduced in v11-02d: Halogen chemistry updates Sulfur oxidation by reactive halogens Add bug fixes for GLYX, MGLY, IEPOX, and IMAE heterogeneous chemistry	GEOS-Chem v11-02
v11-02c-Run0	GEOS-FP 2013	11.596	-0.233 (-1.970%)	Updates introduced in v11-02c: Enhance default GEOS-Chem simple SOA Updates to isoprene and monoterpene chemistry Add aqueous isoprene uptake to SOA scheme Carbon balance (fix C creation) Fix bugs for EOH and MGLY following implementation of PAN updates in v11-02a Update HEMCO from v2.0.004 to v2.1.001	GEOS-Chem v11-02
v11-02a-Run1	GEOS-FP 2013	11.829	.079 (0.672%)	Same as in v11-02a-Run0, but: Partitioning of NOx biomass burning emissions directly to PAN and HNO3 has been removed	GEOS-Chem v11-02
v11-02a-Run0	GEOS-FP 2013	11.750	-0.251 (-2.09%)	Updates introduced in v11-02a: Update chemistry rate constants based on JPL Publication 15-10 Fixes to correct ALK4 lumping issue PAN updates, including: Updates to emissions, deposition, species, chemistry Ocean+biogenic ALD2 emissions from Millet al. [2010] Vertically distributed biomass burning emissions have been removed Monthly mean NEI2011 emissions Bug fixes in the GEOS-Chem sulfate module: Fix error in production of SO4s and NITs in SEASALT_CHEM Fix bug in CHEM_NIT Fix for sulfate production in HET_DROP_CHEM Fix bugs in sulfate chemistry routines Fix bug in dry deposition aerodynamic resistance Bug fix in cos(SZA) for start of timestep Include TOA pressure when calculating dry pressure edges	GEOS-Chem v11-02
v11-01-public-release-Run0	GEOS-FP 2013	12.001	-0.003 (-0.025%)	Updates introduced in v11-01 public release: Bug fix: MAP_A2A now applies periodic boundary conditions only to global data sets during regridding Ocean grid boxes now use the timezone of the nearest land mass for computing emissions	GEOS-Chem v11-01
v11-01k-Run0	GEOS-FP 2013	12.004	-0.065 (-.538%)	Updates introduced in v11-01h: Fix to remove moisture signature in dry mixing ratio Updates introduced in v11-01i: Fix bug in GEOS-FP/MERRA/MERRA-2 re-evaporation calculation Updates introduced in v11-01j: Update to HEMCO v2.0.003, includes: Bug fix for PARANOX extension Fix for ocean overlap in timezones mask file 0.1° x 0.1° CAC emissions Replace RETRO C3H8 emissions with emissions from Xiao 2008, includes: Overwrite Xiao C2H6 and C3H8 with MIX and NEI2011 regional inventories Correct bug in units of EDGAR v4.2 SO2 emissions Prevent biofuel emissions from being double counted in EDGAR v4.2 Set ACTA and HCOOH to active Fix for mesospheric NOx chemistry Fix molecular weight of N2O5 Updates introduced in v11-01k: Lightning update based on Travis et al. (2016, ACP) and Zhang et al. (2014, ACP)	GEOS-Chem v11-01
v11-01g-Run0	GEOS-FP 2013	12.069	0.025 (0.207%)	Updates introduced in v11-01g: FlexChem	GEOS-Chem v11-01
v11-01f-geosfp-Run0	GEOS-FP 2013	12.044	0.033 (0.275%)	Updates introduced in v11-01e: Update HEMCO from version 1.1.005 to version 1.1.016 Updates introduced in v11-01f: New EMEP mask to prevent zero emissions at 30N Optimal timestep settings Bug fixes in globchem.dat for: MOBA + OH --> MOBAOO ISNOOA + NO2 --> PMN	GEOS-Chem v11-01
v11-01d-Run1	GEOS-FP 2013	12.011	0.011 (0.0916%)	Updates introduced in v11-01c: Bug fix for sea salt alkalinity in sulfate_mod.F Bug fixes for the ND21 diagnostic Bug fix for monoterpenes in ND46 diagnostic Updates introduced in v11-01d: CO2 direct effect on isoprene emissions Criegee intermediates Update biomass burning emissions to GFED4.1 Fix for reading hourly NEI2011 emissions	GEOS-Chem v11-01
v11-01b-Run0	GEOS-FP 2013	12.000	0.277 (2.30%)	Updates introduced in v11-01a: Correctly incorporate moisture into air quantities and tracer unit conversions Use tracer units [kg/kg total air] in convection and advection and [v/v dry air] where previously [v/v] Update water vapor saturation formula (Nordquist, 1973) Fix bug in DO_MERRA_CONVECTION affecting mass conservation Reset negative tracer concentrations within advection to small positive values at poles Updates introduced in v11-01b: Update DMS climatology to Lana Impaction scavenging for hydrophobic BC Homogeneous IN removal Density of OA update Improved dust size distribution scheme Now treat DST2-DST4 as coarse mode in wet scavenging Update of PMN + O3 reaction products in globchem.dat file Bug fix for black carbon in ucx_mod.F	GEOS-Chem v11-01

--Bob Yantosca (talk) 18:12, 29 March 2018 (UTC)

Mean OH in GEOS-Chem v10

The following table chronicles the evolution of the mean OH value from several different GEOS-Chem simulations. All benchmark simulations were conducted at 4° x 5° resolution unless noted otherwise.

Benchmark	Met Fields & Year	Mean OH [105 molec cm-3]	Change from prev. version [105 molec cm-3]	Important updates in this benchmark simulation	References
v10-01i-Run0	GEOS-FP 2013	11.125	0.033 (0.298%)	HEMCO emissions component fixes: Bug fixes for the PARANOX HEMCO extension Reprocessed AEIC emissions	v10-01 page HEMCO page Ship emissions page Aircraft emissions page
v10-01h-Run0	GEOS-FP 2013	11.092	-0.751 (-6.341%)	HEMCO emissions component updates: Updates to MEGAN2.1 biogenic emissions Updates to ship NOx chemistry EDGAR v4.2 anthropogenic emissions MIX Asian anthropogenic emissions NEI2011 anthropogenic emissions Reprocessed EMEP emissions for 1990-2012 Updated OTD/LIS factors for GEOS-FP GFED4 biomass burning emissions	v10-01 page HEMCO page MEGAN2.1 page Ship emissions page EDGAR v4.2 page MIX web page NEI2011 page EMEP page Lightning NOx page GFED4 page
v10-01e-Run1	GEOS-FP 2013	11.843	-0.042 (-0.353%)	HEMCO emissions component	v10-01 page HEMCO page
v10-01c-Run1	GEOS-FP 2013	11.885	-0.665 (-5.299%)	UCX chemistry mechanism	v10-01 page UCX page
v10-01c-Run0	GEOS-FP 2013	12.550	-0.139 (-1.095%)	FAST-JX v7.0 photolysis mechanism	v10-01 page FAST-JX page

--Bob Yantosca (talk) 18:12, 29 March 2018 (UTC)

Mean OH in GEOS-Chem v9

The following table chronicles the evolution of the mean OH value from several different GEOS-Chem simulations. All benchmark simulations were conducted at 4° x 5° resolution unless noted otherwise.

Benchmark	Met Fields & Year	Mean OH [105 molec cm-3]	Change from prev. version [105 molec cm-3]	Important updates in this benchmark simulation	References
v9-02r-geosfp-Run1	GEOS-FP 2013	12.689	0.300 (2.421%)	*Global simulations with GEOS-FP data product from GMAO Anthropogenic emissions scaled to 2010 (latest year available) 2011 GFED3 emissions (latest year available) Olson 2001 land map	v9-02 page GEOS-FP page Olson land map page
v9-02r-geosfp-Run0	GEOS-FP 2013	12.389	-0.537 (-4.154%)	Global simulations with GEOS-FP data product from GMAO Anthropogenic and biomass burning emissions scaled to 2005 (same as v9-02r-geos5-Run0)	v9-02 page GEOS-FP page
v9-02r-geos5-Run0	GEOS-5.1.0 2005	12.926	0.356 (2.832%)	AEIC aircraft emissions inventory Cloud water pH for sulfate formation Update jv_spec.dat and jv_spec_aod.dat with better representation of OC growth with RH and correction to sulfate optics Bug fix in CAC NH3 emissions	v9-02 page Aircraft emiss page Sulfate aerosols page Aerosol optical properties page
v9-02l-Run0	GEOS-5.1.0 2005	12.570	0.332 (2.713%)	Updated NH3 seasonal scaling factors over the US Updated Canadian NH3 inventory Fix diurnal NOx scale factors and fix double counting of biofuels over Mexico, Canada, and Europe Bug fix for 3-hourly GFED3 emissions Bug fix for anthropogenic scaling factors for years 2006 and later Correct additional bugs in ship emissions w/ non-local PBL mixing Bug fix for ship CO emissions	v9-02 page Anthro emiss page Ship emiss page
v9-02j-Run0	GEOS-5.1.0 2005	12.238	-0.234 (-1.876%)	Removal of NOx and Ox partitioning Inhibition of N2O5 uptake by nitrate aerosol Improved HO2 uptake by aerosol	v9-02 page Fullchem sim page
v9-02g-Run0	GEOS-5.1.0 2005	12.472	0.969 (8.424%)	Standardize Paulot isoprene scheme Fix RO2+HO2 rate constant	v9-02 page Isoprene scheme page
v9-02f-Run0	GEOS-5.1.0 2005	11.503	0.079 (0.692%)	Inorganic chemistry updates Methyl peroxy nitrate (MPN) chemistry	v9-02 page JPL 10-6 doc MPN chem page
v9-02b-Run0	GEOS-5.1.0 2005	11.424	0.068 (0.599%)	New soil NOx emission module	v9-02 page Soil NOx page
v9-01-03r-Run1	GEOS-5.1.0 2005	11.356	-0.502 (-4.233%)	Bromine chemistry mechanism	v9-01-03 page Bromine chem page
v9-01-03r-Run0	GEOS-5.1.0 2005	11.858	-0.077 (-0.645%)	New implementation of linearized stratospheric chemistry Bug fix for too-low RETRO C2H6 emissions PARANOX plume model for ship emissions	v9-01-03 page Strat chem page Ship emissions page RETRO page
v9-01-03e-Run0	GEOS-5.1.0 2005	11.935	-0.397 (-3.219%)	Improved snow scavenging and washout parameterization	v9-01-03 page
v9-01-02-Run1	GEOS-5.1.0 2005	12.332	+0.099 (+0.809%)	RETRO anthropogenic VOC emissions GFED3 monthly biomass burning emissions	v9-01-02 page
v9-01-02-Run0	GEOS-5.1.0 2005	12.233	-0.009 (-0.074%)	APM aerosol microphysics Various fixes to correct several identified issues	v9-01-02 page
v9-01-01-Run1	GEOS-5.1.0 2005	12.242	+0.377 (+3.177%)	Updated lighting parameterization	v9-01-01 page
v9-01-01-Run0	GEOS-5.1.0 2005	11.865	+0.798 (+7.2%)	ICOADS ship emissions Bug fixes for ship emissions Bug fixes for EPA/NEI05 biofuels Updates for wet scavenging algorithm Several post-release patches to correct various issues	v9-01-01 page Wet deposition page Ship emissions page

--Bob Yantosca (talk) 18:12, 29 March 2018 (UTC)

Mean OH in GEOS-Chem v8

The following table chronicles the evolution of the mean OH value from several different GEOS-Chem simulations. All benchmark simulations were conducted at 4° x 5° resolution unless noted otherwise.

Benchmark	Met Fields & Year	Mean OH [105 molec cm-3]	Change from prev. version [105 molec cm-3]	Important updates in this benchmark simulation	References
v8-02-04-Run2	GEOS-5.1.0 2005	11.067	+0.019 (+0.17%)	Linoz stratospheric ozone chemistry used instead of SYNOZ scheme	Linoz wiki page Talk:v8-02-04 page
v8-02-04-Run1	GEOS-5.1.0 2005	11.048	+0.598 (+5.72%)	MEGAN hybrid model with MODIS-derived LAI	MEGAN wiki page Talk:v8-02-04 page
v8-02-04-Run0	GEOS-5.1.0 2005	10.450	-1.362 (-11.53%)	MEGAN hybrid model with AVHRR-derived LAI EPA/NEI2005 emissions Non-local PBL mixing scheme	MEGAN wiki page NEI2005 wiki page Talk:v8-02-04 page Lin et al 2009
v8-02-01-Run0	GEOS-5.1.0 2005	11.812	+0.713 (+6.42%)	Updated chemical mechanism: globchem.dat Updated photolysis rxn rates: jv_spec.dat, ratj.d NOTE: there was a bug in near IR photolysis of HNO4 and HCHO in the jv_spec.dat and ratj.d files. This was finally resolved in v8-02-04. We recommend all users of v8-02-01, v8-02-02, and v8-02-03 to use these updated jv_spec.dat and ratj.d files.	Chemistry mechanism document FAST-J wiki page
v8-01-04-Run2	GEOS-5.1.0 2005	11.099	+0.805 (+7.82%)	Updated to the newer GEOS-5.1.0 met data product Switched to Hongyu Liu's regridding algorithm for optical depth	GEOS-5 met field reprocessing wiki page GEOS-5 issues wiki page
v8-01-04-Run1	GEOS-5.0.1 2005	10.294	-0.395 (-3.69%)	Various emissions updates with regional overwrites Aaron van Donkelaar et al scale factors for 2005 Switched from linear to random cloud overlap in FAST-J	Anthropogenic emissions in v8-01-04 FAST-J wiki page
v8-01-04-Run0	GEOS-5.0.1 2005	10.689	-1.351 (-11.22%)	New MEGAN annual emission factors for isoprene New TPCORE Quick fix for optical depths	Biogenic emissions wiki page GEOS-5 issues wiki page
v8-01-01-Run1	GEOS-5.0.1 2005	12.040	+0.034 (+0.28%)	Switched aerosol thermodynamical equilibrium scheme from ISORROPIA I to RPMARES	ATE wiki page
v8-01-01-Run0	GEOS-5.0.1 2005	12.006	-0.141 (-1.16%)	First simulation with GEOS-5 met data	GEOS-5 issues wiki page

--Bob Yantosca (talk) 18:11, 29 March 2018 (UTC)

Additional information for GEOS-Chem v8

• Differences in isoprene between v8-02-04-Run1 and v8-02-04-Run0
• Differences between MODIS LAI and AVHRR LAI

--Bob Yantosca (talk) 19:12, 29 March 2018 (UTC)

Mean OH in GEOS-Chem v7

The following table chronicles the evolution of the mean OH value from several different GEOS-Chem simulations. All benchmark simulations were conducted at 4° x 5° resolution unless noted otherwise.

Benchmark	Met Fields & Year	Mean OH [105 molec cm-3]	Change from prev. version [105 molec cm-3]	Important updates in this benchmark simulation	References
v7-04-13-Run	GEOS-4 2005	12.147	-0.669 (-5.22%)	Updated non-near-land OTD/LIS local scaling for lightning	Lightning wiki page
v7-04-12-Run2	GEOS-4 2005	12.816	+1.053 (+8.95%)	Original non-near-land OTD/LIS local scaling	Lightning wiki page Hudman PDF v7-04-12 diff list
v7-04-12-Run1	GEOS-4 2005	11.763	-0.68 (-5.5%)	Ancient lightning scheme	Lightning wiki page Hudman PDF v7-04-12 diff list
v7-04-02-MEGAN	GEOS-4 2001	12.44	-0.11 (-0.87%)	First benchmark w/ MEGAN biogenic emissions	MEGAN wiki page Hudman PDF v7-04-02 diff list
v7-04-02-NOMEGAN	GEOS-4 2001	12.55	+0.01 (+0.08%)	Switched fossil fuel scale year from 1995 to 1998 Last benchmark w/ the older GEIA biogenic emissions	GEIA wiki page Hudman PDF v7-04-02 diff list
v7-04-02-Base	GEOS-4 2001	12.54	+0.67 (+5.6%)	43 tracer simulation (no secondary organic aerosols) Last 1-yr benchmark with fossil fuel scale year = 1995	Hudman PDF v7-04-02 diff list
v7-02-03-Run1	GEOS-4 2001	11.87	+1.39 (+13.26%)	Secondary organic aerosols (50 tracers) GEOS-4 met fields	SOA wiki page Hudman PDF
v7-02-03-Run0	GEOS-3 2001	10.48	---	Secondary organic aerosols (50 tracers) GEOS-3 2001	SOA wiki page Hudman PDF

--Bob Yantosca (talk) 18:11, 29 March 2018 (UTC)

Additional information for GEOS-Chem v7

• Rynda Hudman investigated the changes in CO and O3 among benchmark simulations from v7-02-03 thru v7-04-12.
• List of differences in benchmark simulations between v7-02-03 and v7-04-02.
• List of differences in benchmark simulations between v7-04-02 and v7-04-12.
• Changes in anthropogenic NOx and CO from 1-yr benchmarks with versions v7-02-03 and v7-02-04
• Jennifer Logan looked at some of the differences between GEOS-3 and GEOS-4 in 1-year benchmark simulations.

--Bob Yantosca (talk) 19:13, 29 March 2018 (UTC)