A mechanistic modeling system for estimating large-scale emissions and transport of pollen and co-allergens

Abstract

Allergic airway diseases represent a complex health problem which can be exacerbated by the synergistic action of pollen particles and air pollutants such as ozone. Understanding human exposures to aeroallergens requires accurate estimates of the spatial distribution of airborne pollen levels as well as of various air pollutants at different times. However, currently there are no established methods for estimating allergenic pollen emissions and concentrations over large geographic areas such as the United States. A mechanistic modeling system for describing pollen emissions and transport over extensive domains has been developed by adapting components of existing regional scale air quality models and vegetation databases. First, components of the Biogenic Emissions Inventory System (BEIS) were adapted to predict pollen emission patterns. Subsequently, the transport module of the Community Multiscale Air Quality (CMAQ) modeling system was modified to incorporate description of pollen transport. The combined model, CMAQ-pollen, allows for simultaneous prediction of multiple air pollutants and pollen levels in a single model simulation, and uses consistent assumptions related to the transport of multiple chemicals and pollen species. Application case studies for evaluating the combined modeling system included the simulation of birch and ragweed pollen levels for the year 2002, during their corresponding peak pollination periods (April for birch and September for ragweed). The model simulations were driven by previously evaluated meteorological model outputs and emissions inventories for the eastern United States for the simulation period. A semi-quantitative evaluation of CMAQ-pollen was performed using tree and ragweed pollen counts in Newark, NJ for the same time periods. The peak birch pollen concentrations were predicted to occur within two days of the peak measurements, while the temporal patterns closely followed the measured profiles of overall tree pollen. For the case of ragweed pollen, the model was able to capture the patterns observed during September 2002, but did not predict an early peak; this can be associated with a wider species pollination window and inadequate spatial information in current land cover databases. An additional sensitivity simulation was performed to comparatively evaluate the dispersion patterns predicted by CMAQ-pollen with those predicted by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, which is used extensively in aerobiological studies. The CMAQ estimated concentration plumes matched the equivalent pollen scenario modeled with HYSPLIT. The novel pollen modeling approach presented here allows simultaneous estimation of multiple airborne allergens and other air pollutants, and is being developed as a central component of an integrated population exposure modeling system, the Modeling Environment for Total Risk studies (MENTOR) for multiple, co-occurring contaminants that include aeroallergens and irritants.

MACC regional multi-model ensemble simulations of birch pollen dispersion in Europe

“…Development is also going on in Denmark with the regional ENVIRO-HIRLAM system (Mahura et al, 2009) applied for forecasting over northern Europe. Finally, combining the COSMO-ART and SILAM source terms, Efstathiou et al (2011) developed a regional-scale model for the USA and applied it to birch and ragweed.…”

A High-resolution Numerical Simulation and Evaluation of Oak Pollen Dispersion Using the CMAQ-pollen Model

“…최근에는 제한된 꽃가루 모니터링자료와 통계 모델의 한계를 보완하기 위해 꽃가루 수치모델링 방법 이 구체적으로 제안되었고 (Efstathiou et al, 2011;D'Amato et al, 2007;Sofiev et al, 2006) Zhang et al, 2013). 하지만 성공적인 수치모델링에 있어 꽃가루 배 출량 추정의 불확실성, 물리적 특성과 침적과정의 정 확한 고려, 식생입력자료의 한계 극복을 위해서 지속 적인 연구가 필요할 것이다.…”

“…Further efforts are needed to further understand the oak pollen release characteristics such as interannual variation of the oak pollen productivity and its spatio-temporal flowering timing. et al, 2011;Vogel et al, 2008;Sofiev et al, 2006 먼저 수종의 특성농도 c*항은 식 3과 같이 정의된다 (Efstathiou et al, 2011;Helbing et al, 2004).…”

Ragweed pollen production and dispersion modelling within a regional climate system, calibration and application over Europe

“…Presently a number of regional models, mostly designed for air quality prevision, incorporate release and dispersion dynamics of pollen (Helbig et al, 2004;Sofiev et al, 2006Sofiev et al, , 2013Skjøth, 2009;Efstathiou et al, 2011;Zink et al, 2012;Prank et al, 2013;Zhang et al, 2014). Methods for producing ragweed pollen emission suitable for input to regional scale models have been developed in recent studies (Skjøth et al, 2010;Šikoparija et al, 2012;Chapman et al, 2014).…”

“…Here const = 0.02 is assumed to be the maximal density (plant m −2 ) in the most suitable habitats (Efstathiou et al, 2011), H (x, y) taken as the crop and urban lands in CMIP5 land use classification (Hurtt et al, 2006). For countries with low-quality observations or with no available inventories, the detection probability is replaced by the average over neighbouring countries with reliable data.…”