Errors and improvements in the use of archived meteorological  data for chemical transport modeling: an analysis using GEOS-Chem v11-01 driven by GEOS-5 meteorology

Yu, Karen; Keller, Christoph A.; Jacob, Daniel J.; Molod, Andrea; Eastham, Sebastian D.; Long, M. S.

doi:10.5194/gmd-11-305-2018

Cited by 65 publications

(88 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, Pai et al (2019) indicate that GEOS-Chem does not generally underestimate OA in the upper troposphere, although their comparisons with data are limited to below 10 km. The study by Yu et al (2018) indicates that intensification of simulated convection in the Asian monsoon region would raise aerosol concentrations (and SR values) in the simulated ATAL, similar to that achieved in limiting SO 2 scavenging (ModSim). Assuming lower lidar ratios to convert modeled extinction coefficient to SR does not solve the problem; the peak in simulated SR is intensified, but the vertical distribution (i.e., the shape) remains unaffected.…”

Section: 1029/2019jd031506mentioning

confidence: 71%

“…Yu et al () demonstrated that remapping of meteorological data from the native cubed‐sphere grid of the parent GCM (GEOS‐5) to an equivalent‐resolution latitude‐longitude grid, and 3‐hr‐averaging of the fields, led to vertical transport errors of 20% in offline CTM (GEOS‐Chem) simulations of a surface‐source tracer, 222 Rn, compared to online 222 Rn simulations (their Figure 2). Yu et al () attributed this error, in part, to a loss of transient organized vertical motions. Further degradation of the spatial resolution of the meteorological data to 2° × 2.5° (as used in our study) led to 222 Rn concentrations biased 40% low in the upper troposphere, relative to online 222 Rn simulations (their Figure 3), due to further weakening of vertical transport via spatial averaging.…”

Section: Sensitivity To Wet Scavenging Efficiency Of So2mentioning

confidence: 99%

See 1 more Smart Citation

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

et al. 2020

View full text Add to dashboard Cite

The Asian Tropopause Aerosol Layer (ATAL) represents an accumulation of aerosol in the upper troposphere and lower stratosphere associated with the Asian Summer Monsoon. Here we simulate the ATAL for summer 2013 with the GEOS‐Chem chemical transport model and explore the likely composition of ATAL aerosols and the relative contributions of regional anthropogenic sources versus those from farther afield. The model indicates significant contributions from organic aerosol, nitrate, sulfate, and ammonium aerosol, with regional anthropogenic precursor sources dominant. The model underestimates aerosol backscatter in the ATAL during summer 2013, compared with Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite instrument. Tests of a more physically based treatment of wet scavenging of SO2 in convective updrafts raise sulfate, eliminating the low bias with respect to CALIPSO backscatter in the ATAL, but lead to an unacceptable high bias of sulfate compared with in situ observations from aircraft over the United States. Source apportionment of the model results indicate the dominance of regional anthropogenic emissions from China and the Indian subcontinent to aerosol concentrations in the ATAL; ~60% of sulfate in the ATAL region in August 2013 is attributable to anthropogenic sources of SO2 from China (~30%) and from the Indian subcontinent (~30%), twice as much as in previously published estimates. Nitrate aerosol is found to be a dominant component of aerosol composition on the southern flank of the Asian Summer Monsoon anticyclone. Lightning sources of NOx are found to make a significant (10–15%) contribution to nitrate in the ATAL for the case studied.

show abstract

Section: 1029/2019jd031506mentioning

confidence: 71%

Section: Sensitivity To Wet Scavenging Efficiency Of So2mentioning

confidence: 99%

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

et al. 2020

View full text Add to dashboard Cite

show abstract

“…A comparison of modeled versus observed PBL:FT VOC concentration ratios over the southeastern US suggests that inadequate PBL ventilation in the model may play a role in driving the observed FT biases. Recent work has sought to improve CTM transport performance through improved spatial resolution (e.g., (Zhuang et al, 2018;Yu et al, 2016)), through use of a cubed-sphere rather than regular Cartesian grid (e.g., (Eastham et al, 2018;Yu et al, 2018)), and by integration into Atmos. Chem.…”

Section: Discussionmentioning

confidence: 99%

On the sources and sinks of atmospheric VOCs: An integrated analysis of recent aircraft campaigns over North America

Chen¹,

Millet²,

Singh³

et al. 2019

Preprint

View full text Add to dashboard Cite

Abstract. We apply a high-resolution chemical transport model (GEOS-Chem CTM) with updated treatment of volatile organic compounds (VOCs) and a comprehensive suite of airborne datasets over North America to i) characterize the VOC budget, and ii) test the ability of current models to capture the distribution and reactivity of atmospheric VOCs, over this region. Biogenic emissions dominate the North American VOC budget in the model, accounting for 70&#8201;% and 95&#8201;% of annually emitted VOC-carbon and reactivity, respectively. Based on current inventories anthropogenic emissions have declined to the point where biogenic emissions are the dominant summertime source of VOC reactivity even in most major North American cities. Methane oxidation is a 2&#215; larger source of non-methane VOCs (via production of formaldehyde and methyl hydroperoxide) over North America in the model than are anthropogenic emissions. However, anthropogenic VOCs account for over half the ambient VOC loading over the majority of the region owing to their longer aggregate lifetime. Fires can be a significant VOC source episodically but are small on average. In the planetary boundary layer (PBL), the model exhibits skill in capturing observed variability in total VOC-abundance (R2&#8201;=&#8201;0.36) and reactivity (R2&#8201;=&#8201;0.54). The same is not true in the free troposphere (FT), where skill is low and there is a persistent low model bias (~&#8201;60&#8201;%), with most (27 of 34) model VOCs underestimated by more than a factor of 2. A comparison of PBL&#8201;:&#8201;FT concentration ratios over the southeastern US points to a misrepresentation of PBL ventilation as a contributor to these model FT biases. We also find that a relatively small number of VOCs (acetone, methanol, ethane, acetaldehyde, formaldehyde, isoprene&#8201;+&#8201;oxidation products, methyl hydroperoxide) drive a large fraction of total ambient VOC reactivity and associated model biases; research to improve understanding of their budgets is thus warranted. A source tracer analysis suggests a current overestimate of biogenic sources for hydroxyacetone, methyl ethyl ketone and glyoxal, an underestimate of biogenic formic acid sources, and an underestimate of peroxyacetic acid production across biogenic and anthropogenic precursors. Future work to improve model representations of vertical transport and to address the VOC biases discussed are needed to advance predictions of ozone and SOA formation.

show abstract

“…GEOS-Chem mercury simulations using this meteorological data have been extensively compared to wet deposition and concentration measurements over the region of interest. 8,57,58 Yu et al 63 have recently reported that the use of offline meteorological archives to drive chemical transport simulations such as GEOS-Chem may lead to vertical transport errors that bias surface concentrations of chemical tracers high, and upper troposphere concentrations low. Consequently, these simulations may underestimate the extent of global mercury transport and its contribution to Great Lakes mercury deposition.…”

Section: Meteorologymentioning

confidence: 99%

Understanding factors influencing the detection of mercury policies in modelled Laurentian Great Lakes wet deposition

Giang

Song

Muntean

et al. 2018

Environ. Sci.: Processes Impacts

View full text Add to dashboard Cite

We used chemical transport modelling to better understand the extent to which policy-related anthropogenic mercury emissions changes (a policy signal) can be statistically detected in wet deposition measurements in the Great Lakes region on the subdecadal scale, given sources of noise. In our modelling experiment, we consider hypothetical regional (North American) and global (rest of the world) policy changes, consistent with existing policy efforts (Δglobal = -18%; Δregional = -30%) that divide an eight-year period. The magnitude of statistically significant (p < 0.1) pre- and post-policy period wet deposition differences, holding all else constant except for the policy change, ranges from -0.3 to -2.0% for the regional policy and -0.8 to -2.7% for the global policy. We then introduce sources of noise-trends and variability in factors that are exogenous to the policy action-and evaluate the extent to which the policy signals can still be detected. For instance, technology-related variability in emissions magnitude and speciation can shift the magnitude of differences between periods, in some cases dampening the policy effect. We have found that the interannual variability in meteorology has the largest effect of the sources of noise considered, driving deposition differences between periods to ±20%, exceeding the magnitude of the policy signal. However, our simulations suggest that gaseous elemental mercury concentration may be more robust to this meteorological variability in this region, and a stronger indicator of local/regional emissions changes. These results highlight the potential challenges of detecting statistically significant policy-related changes in Great Lakes wet deposition within the subdecadal scale.

show abstract

Errors and improvements in the use of archived meteorological data for chemical transport modeling: an analysis using GEOS-Chem v11-01 driven by GEOS-5 meteorology

Cited by 65 publications

References 49 publications

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

On the sources and sinks of atmospheric VOCs: An integrated analysis of recent aircraft campaigns over North America

Understanding factors influencing the detection of mercury policies in modelled Laurentian Great Lakes wet deposition

Contact Info

Product

Resources

About