Model evaluation of CO2 and SF6 in the extratropical UT/LS region

Bönisch, Harald; Hoor, Peter; Gurk, C.; Feng, Wuhu; Chipperfield, Martyn P.; Engel, Andreas; Bregman, B.

doi:10.1029/2007jd008829

Cited by 28 publications

(24 citation statements)

References 70 publications

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“…Diurnal variability in the BL height is determined using the parameterization of Vogelezang and Holtslag (1996). We use the first-order moments scheme with an iterative time step to prevent too much mass being transported out of any particular grid cell according to the preservation of the Courant-Friedrichs-Lewy (CFL) criterion (Bregman et al, 2003), which is especially relevant when reducing the size of grid cells as done here.…”

Section: Description Of Tm5-mpmentioning

confidence: 99%

The high-resolution version of TM5-MP for optimized satellite retrievals: description and validation

et al. 2017

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Abstract. We provide a comprehensive description of the high-resolution version of the TM5-MP global chemistry transport model, which is to be employed for deriving highly resolved vertical profiles of nitrogen dioxide (NO2), formaldehyde (CH2O), and sulfur dioxide (SO2) for use in satellite retrievals from platforms such as the Ozone Monitoring Instrument (OMI) and the Sentinel-5 Precursor, and the TROPOspheric Monitoring Instrument (tropOMI). Comparing simulations conducted at horizontal resolutions of 3°  ×  2° and 1°  ×  1° reveals differences of ±20 % exist in the global seasonal distribution of 222Rn, being larger near specific coastal locations and tropical oceans. For tropospheric ozone (O3), analysis of the chemical budget terms shows that the impact on globally integrated photolysis rates is rather low, in spite of the higher spatial variability of meteorological data fields from ERA-Interim at 1°  ×  1°. Surface concentrations of O3 in high-NOx regions decrease between 5 and 10 % at 1°  ×  1° due to a reduction in NOx recycling terms and an increase in the associated titration term of O3 by NO. At 1°  ×  1°, the net global stratosphere–troposphere exchange of O3 decreases by ∼  7 %, with an associated shift in the hemispheric gradient. By comparing NO, NO2, HNO3 and peroxy-acetyl-nitrate (PAN) profiles against measurement composites, we show that TM5-MP captures the vertical distribution of NOx and long-lived NOx reservoirs at background locations, again with modest changes at 1°  ×  1°. Comparing monthly mean distributions in lightning NOx and applying ERA-Interim convective mass fluxes, we show that the vertical re-distribution of lightning NOx changes with enhanced release of NOx in the upper troposphere. We show that surface mixing ratios in both NO and NO2 are generally underestimated in both low- and high-NOx scenarios. For Europe, a negative bias exists for [NO] at the surface across the whole domain, with lower biases at 1°  ×  1° at only ∼  20 % of sites. For NO2, biases are more variable, with lower (higher) biases at 1°  ×  1° occurring at ∼  35 % ( ∼  20 %) of sites, with the remainder showing little change. For CH2O, the impact of higher resolution on the chemical budget terms is rather modest, with changes of less than 5 %. The simulated vertical distribution of CH2O agrees reasonably well with measurements in pristine locations, although column-integrated values are generally underestimated relative to satellite measurements in polluted regions. For SO2, the performance at 1°  ×  1° is principally governed by the quality of the emission inventory, with limited improvements in the site-specific biases, with most showing no significant improvement. For the vertical column, improvements near strong source regions occur which reduce the biases in the integrated column. For remote regions missing biogenic source terms are inferred.

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Section: Description Of Tm5-mpmentioning

confidence: 99%

The high-resolution version of TM5-MP for optimized satellite retrievals: description and validation

et al. 2017

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“…By using a seasonally varying a priori retrieval the seasonality might be slightly higher because the amplitude of CO 2 is better retrieved (Barthlott et al, 2015). Furthermore, in the tropopause and the lower stratosphere, the phase of the CO 2 seasonality is shifted by several months (Bönisch et al, 2008(Bönisch et al, , 2009Gurk et al, 2008). However, this has only a minor influence on the observed dampening of the amplitude of the FTIR seasonality compared to the vertical mixing, since the stratosphere contains only about 10 % of the abundance of atmospheric air molecules.…”

Section: Discussionmentioning

confidence: 99%

Intercomparison of in situ NDIR and column FTIR measurements of CO2 at Jungfraujoch

et al. 2016

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Abstract. We compare two CO2 time series measured at the High Alpine Research Station Jungfraujoch, Switzerland (3580 m a.s.l.), in the period from 2005 to 2013 with an in situ surface measurement system using a nondispersive infrared analyzer (NDIR) and a ground-based remote sensing system using solar absorption Fourier transform infrared (FTIR) spectrometry. Although the two data sets show an absolute shift of about 13 ppm, the slopes of the annual CO2 increase are in good agreement within their uncertainties. They are 2.04 ± 0.07 and 1.97 ± 0.05 ppm yr−1 for the FTIR and the NDIR systems, respectively. The seasonality of the FTIR and the NDIR systems is 4.46 ± 1.11 and 10.10 ± 0.73 ppm, respectively. The difference is caused by a dampening of the CO2 signal with increasing altitude due to mixing processes. Whereas the minima of both data series occur in the middle of August, the maxima of the two data sets differ by about 10 weeks; the maximum of the FTIR measurements is in the middle of January, and the maximum of the NDIR measurements is found at the end of March. Sensitivity analyses revealed that the air masses measured by the NDIR system at the surface of Jungfraujoch are mainly influenced by central Europe, whereas the air masses measured by the FTIR system in the column above Jungfraujoch are influenced by regions as far west as the Caribbean and the USA.The correlation between the hourly averaged CO2 values of the NDIR system and the individual FTIR CO2 measurements is 0.820, which is very encouraging given the largely different sampling volumes. Further correlation analyses showed, that the correlation is mainly driven by the annual CO2 increase and to a lesser degree by the seasonality. Both systems are suitable to monitor the long-term CO2 increase, because this signal is represented in the whole atmosphere due to mixing.

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“…The model also has the option of using the secondorder moments scheme (Prather, 1986), but this has not been used in the evaluation presented in this paper. The second-order moments scheme has recently been shown to improve the transport in the upper troposphere and lower stratosphere (UTLS) when applied in TM5 (Bönisch et al, 2008), but at increased computational expense. Both deep and shallow cumulus convection is evaluated according to the Tiedtke scheme (1989).…”

Section: Tracer Transportmentioning

confidence: 99%

The global chemistry transport model TM5: description and evaluation of the tropospheric chemistry version 3.0

Huijnen¹,

Williams²,

Weele³

et al. 2010

Preprint

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We present a comprehensive description and benchmark evaluation of the tropospheric chemistry version of the global chemistry transport model TM5 (Tracer Model 5, version TM5-chem-v3.0). A full description is given concerning the photochemical mechanism, the interaction with aerosol, the treatment of the stratosphere, the wet and dry deposition parameterizations, and the applied emissions. We evaluate the model against a suite of ground-based, satellite, and aircraft measurements of components critical for understanding global photochemistry for the year 2006. The model exhibits a realistic oxidative capacity at a global scale. The methane lifetime is ~8.9 years with an associated lifetime of methyl chloroform of 5.86 years, which is similar to that derived using an optimized hydroxyl radical field. The seasonal cycle in observed carbon monoxide (CO) is well simulated at different regions across the globe. In the Northern Hemisphere CO concentrations are underestimated by about 20 ppbv in spring and 10 ppbv in summer, which is related to missing chemistry and underestimated emissions from higher hydrocarbons, as well as to uncertainties in the seasonal variation of CO emissions. The model also captures the spatial and seasonal variation in formaldehyde tropospheric columns as observed by SCIAMACHY. Positive model biases over the Amazon and eastern United States point to uncertainties in the isoprene emissions as well as its chemical breakdown. Simulated tropospheric nitrogen dioxide columns correspond well to observations from the Ozone Monitoring Instrument in terms of its seasonal and spatial variability (with a global spatial correlation coefficient of 0.89), but TM5 fields are lower by 25–40%. This is consistent with earlier studies pointing to a high bias of 0–30% in the OMI retrievals, but uncertainties in the emission inventories have probably also contributed to the discrepancy. TM5 tropospheric nitrogen dioxide profiles are in good agreement (within ~0.1 ppbv) with in situ aircraft observations from the INTEX-B campaign over (the Gulf of) Mexico. The model reproduces the spatial and seasonal variation in background surface ozone concentrations and tropospheric ozone profiles from the World Ozone and Ultraviolet Radiation Data Centre to within 10 ppbv, but at several tropical stations the model tends to underestimate ozone in the free troposphere. The presented model results benchmark the TM5 tropospheric chemistry version, which is currently in use in several international cooperation activities, and upon which future model improvements will take place

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Model evaluation of CO₂ and SF₆ in the extratropical UT/LS region

Cited by 28 publications

References 70 publications

The high-resolution version of TM5-MP for optimized satellite retrievals: description and validation

The high-resolution version of TM5-MP for optimized satellite retrievals: description and validation

Intercomparison of in situ NDIR and column FTIR measurements of CO<sub>2</sub> at Jungfraujoch

The global chemistry transport model TM5: description and evaluation of the tropospheric chemistry version 3.0

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Model evaluation of CO2 and SF6 in the extratropical UT/LS region

Cited by 28 publications

References 70 publications

The high-resolution version of TM5-MP for optimized satellite retrievals: description and validation

The high-resolution version of TM5-MP for optimized satellite retrievals: description and validation

Intercomparison of in situ NDIR and column FTIR measurements of CO&lt;sub&gt;2&lt;/sub&gt; at Jungfraujoch

The global chemistry transport model TM5: description and evaluation of the tropospheric chemistry version 3.0

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Model evaluation of CO₂ and SF₆ in the extratropical UT/LS region

Intercomparison of in situ NDIR and column FTIR measurements of CO<sub>2</sub> at Jungfraujoch