Inclusion of ash and SO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; emissions from volcanic eruptions in WRF-Chem: development and some applications

Stuefer, Martin; Freitas, Saulo R.; Grell, Georg; Webley, P. W.; Peckham, Steven E.; McKeen, S. A.; Egan, Sean D.

doi:10.5194/gmd-6-457-2013

Cited by 55 publications

(59 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The new error covariance matrix

B^{new}

represents the uncertainty of u b ,new that should be smaller than

B_{k}

. The vertical distribution could be based on explicit assumptions, such as uniform‐distributed [ Dacre et al , ], umbrella‐shaped [ Stuefer et al , ; Webley et al , ], Poisson‐distributed, exponentially distributed plume [ Searcy et al , ], or based on characteristics of the current eruption type.…”

Section: Assimilation Methodologymentioning

confidence: 99%

Estimation of volcanic ash emissions through assimilating satellite data and ground‐based observations

et al. 2016

View full text Add to dashboard Cite

In this paper, we reconstruct the vertical profile of volcanic ash emissions by assimilating satellite data and ground‐based observations using a modified trajectory‐based 4D‐Var (Trj4DVar) approach. In our previous work, we found that the lack of vertical resolution in satellite ash column data can result in a poor estimation of the injection layer where the ash is emitted into the atmosphere. The injection layer is crucial for the forecast of volcanic ash clouds. To improve estimation, Trj4DVar was implemented, and it has shown increased performance in twin experiments using synthetic observations. However, there are some cases with real satellite data where Trj4DVar has difficulty in obtaining an accurate estimation of the injection layer. To remedy this, we propose a modification of Trj4DVar, test it with synthetic twin experiments, and evaluate real data performance. The results show that the modified Trj4DVar is able to accurately estimate the injection height (location of the maximal emission rate) by incorporating the plume height (top of the ash plume) and mass eruption rate data obtained from ground‐based observations near the source into the assimilation system. This will produce more accurate emission estimations and more reliable forecasts of volcanic ash clouds. Also provided are two strategies on the preprocessing and proper use of satellite data.

show abstract

“…The new error covariance matrix

B^{new}

represents the uncertainty of u b ,new that should be smaller than

B_{k}

Section: Assimilation Methodologymentioning

confidence: 99%

Estimation of volcanic ash emissions through assimilating satellite data and ground‐based observations

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Resolving more meso-scale circulations, and improved representation of topography can be particularly advantageous, as they can cause large gradients in CO 2 (de Wekker et al, 2005;van der Molen and Dolman, 2007). While WRF-Chem is used for a variety of atmospheric transport studies (among others: Tie et al, 2009;de Foy et al, 2011;Lee et al, 2011;Stuefer et al, 2013), more general air quality studies have shown that an ensemble of models can forecast air pollution situations more accurately than a single model (Galmarini et al, 2004(Galmarini et al, , 2013. While in our research we focused on the transport of CO 2 and 14 CO 2 , other chemically active tracers (e.g.…”

Section: Discussionmentioning

confidence: 99%

Simulating the integrated summertime Δ<sup>14</sup>CO<sub>2</sub> signature from anthropogenic emissions over Western Europe

et al. 2014

View full text Add to dashboard Cite

Abstract. Radiocarbon dioxide ( 14 CO 2 , reported in 14 CO 2 ) can be used to determine the fossil fuel CO 2 addition to the atmosphere, since fossil fuel CO 2 no longer contains any 14 C. After the release of CO 2 at the source, atmospheric transport causes dilution of strong local signals into the background and detectable gradients of 14 CO 2 only remain in areas with high fossil fuel emissions. This fossil fuel signal can moreover be partially masked by the enriching effect that anthropogenic emissions of 14 CO 2 from the nuclear industry have on the atmospheric 14 CO 2 signature. In this paper, we investigate the regional gradients in 14 CO 2 over the European continent and quantify the effect of the emissions from nuclear industry. We simulate the emissions and transport of fossil fuel CO 2 and nuclear 14 CO 2 for Western Europe using the Weather Research and Forecast model (WRF-Chem) for a period covering 6 summer months in 2008. We evaluate the expected CO 2 gradients and the resulting 14 CO 2 in simulated integrated air samples over this period, as well as in simulated plant samples.We find that the average gradients of fossil fuel CO 2 in the lower 1200 m of the atmosphere are close to 15 ppm at a 12 km × 12 km horizontal resolution. The nuclear influence on 14 CO 2 signatures varies considerably over the domain and for large areas in France and the UK it can range from 20 to more than 500 % of the influence of fossil fuel emissions. Our simulations suggest that the resulting gradients in 14 CO 2 are well captured in plant samples, but due to their time-varying uptake of CO 2 , their signature can be different with over 3 ‰ from the atmospheric samples in some regions. We conclude that the framework presented will be well-suited for the interpretation of actual air and plant 14 CO 2 samples.

show abstract

“…Different dust schemes will produce different dust emission fluxes over arid and semi-arid regions (Zhao et al, 2010;Su and Fung, 2015). Several factors, such as potential source regions, threshold friction velocity, size distribution, and other surface and soil-related parameters used in equations, can be the primary causes for the inconsistency, and the differences in simulated dust emissions will affect the characteristics of spatial-temporal variations of atmospheric aerosol particles.…”

Section: Dust Schemementioning

confidence: 99%

MICS-Asia III: multi-model comparison and evaluation of aerosol over East Asia

et al. 2019

View full text Add to dashboard Cite

Abstract. A total of 14 chemical transport models (CTMs) participated in the first topic of the Model Inter-Comparison Study for Asia (MICS-Asia) phase III. These model results are compared with each other and an extensive set of measurements, aiming to evaluate the current CTMs' ability in simulating aerosol concentrations, to document the similarities and differences among model performance, and to reveal the characteristics of aerosol components in large cities over East Asia. In general, these CTMs can well reproduce the spatial–temporal distributions of aerosols in East Asia during the year 2010. The multi-model ensemble mean (MMEM) shows better performance than most single-model predictions, with correlation coefficients (between MMEM and measurements) ranging from 0.65 (nitrate, NO3-) to 0.83 (PM2.5). The concentrations of black carbon (BC), sulfate (SO42-), and PM10 are underestimated by MMEM, with normalized mean biases (NMBs) of −17.0 %, −19.1 %, and −32.6 %, respectively. Positive biases are simulated for NO3- (NMB = 4.9 %), ammonium (NH4+) (NMB = 14.0 %), and PM2.5 (NMB = 4.4 %). In comparison with the statistics calculated from MICS-Asia phase II, frequent updates of chemical mechanisms in CTMs during recent years make the intermodel variability of simulated aerosol concentrations smaller, and better performance can be found in reproducing the temporal variations of observations. However, a large variation (about a factor of 2) in the ratios of SNA (sulfate, nitrate, and ammonium) to PM2.5 is calculated among participant models. A more intense secondary formation of SO42- is simulated by Community Multi-scale Air Quality (CMAQ) models, because of the higher SOR (sulfur oxidation ratio) than other models (0.51 versus 0.39). The NOR (nitric oxidation ratio) calculated by all CTMs has larger values (∼0.20) than the observations, indicating that overmuch NO3- is simulated by current models. NH3-limited condition (the mole ratio of ammonium to sulfate and nitrate is smaller than 1) can be successfully reproduced by all participant models, which indicates that a small reduction in ammonia may improve the air quality. A large coefficient of variation (CV > 1.0) is calculated for simulated coarse particles, especially over arid and semi-arid regions, which means that current CTMs have difficulty producing similar dust emissions by using different dust schemes. According to the simulation results of MMEM in six large Asian cities, different air-pollution control plans should be taken due to their different major air pollutants in different seasons. The MICS-Asia project gives an opportunity to discuss the similarities and differences of simulation results among CTMs in East Asian applications. In order to acquire a better understanding of aerosol properties and their impacts, more experiments should be designed to reduce the diversities among air quality models.

show abstract

Inclusion of ash and SO<sub>2</sub> emissions from volcanic eruptions in WRF-Chem: development and some applications

Cited by 55 publications

References 47 publications

Estimation of volcanic ash emissions through assimilating satellite data and ground‐based observations

Estimation of volcanic ash emissions through assimilating satellite data and ground‐based observations

Simulating the integrated summertime Δ<sup>14</sup>CO<sub>2</sub> signature from anthropogenic emissions over Western Europe

MICS-Asia III: multi-model comparison and evaluation of aerosol over East Asia

Contact Info

Product

Resources

About

Inclusion of ash and SO&lt;sub&gt;2&lt;/sub&gt; emissions from volcanic eruptions in WRF-Chem: development and some applications

Cited by 55 publications

References 47 publications

Estimation of volcanic ash emissions through assimilating satellite data and ground‐based observations

Estimation of volcanic ash emissions through assimilating satellite data and ground‐based observations

Simulating the integrated summertime Δ&lt;sup&gt;14&lt;/sup&gt;CO&lt;sub&gt;2&lt;/sub&gt; signature from anthropogenic emissions over Western Europe

MICS-Asia III: multi-model comparison and evaluation of aerosol over East Asia

Contact Info

Product

Resources

About

Inclusion of ash and SO<sub>2</sub> emissions from volcanic eruptions in WRF-Chem: development and some applications

Simulating the integrated summertime Δ<sup>14</sup>CO<sub>2</sub> signature from anthropogenic emissions over Western Europe