Lauer Axel, Eyring Veronika, Corbett James J, Wang Chengfeng, Winebrake James J
International Pacific Research Center, University of Hawaii, 1680 East-West Road, Honolull, Hawaii 96822, USA.
Environ Sci Technol. 2009 Aug 1;43(15):5592-8. doi: 10.1021/es900922h.
We apply the global climate model ECHAM5/MESSy1-MADE with detailed aerosol and cloud microphysics to study the impact of shipping on tropospheric aerosol burdens, clouds, and the radiation budget for four near-future ship emission policy scenarios for the year 2012. We compare a "No Control" scenario with global sulfur limits and regionally applied reductions. We show that, if no control measures are taken, near surface sulfate increases by about 10-20% over the main transoceanic shipping routes from 2002 to 2012. A reduction of the maximum fuel sulfur (S) content allowed within 200 nautical miles of coastal areas ("global emission control areas") to 0.5% or 0.1% (5000 or 1000 ppm S, respectively) results in a distinctive reduction in near surface sulfate from shipping in coastal regions compared with the year 2002. The model results also show that if emissions of nitrogen oxides (NO(x)) remain unabated, a reduction of the fuel sulfur content favors a strong increase in aerosol nitrate (NO3) which could counteract up to 20% of the decrease in sulfate mass achieved by sulfur emission reductions. The most important impact of shipping on the radiation budget is related to the modification of low maritime stratus clouds resulting in an increased reflectivity and enhanced shortwave cloud forcing. The direct aerosol effect from shipping is small. Our study shows that one can expect a less negative (less cooling) radiative forcing due to reductions in the current fuel sulfur content of ocean-going ships. The global annual average net cloud forcings due to shipping (year 2012) are in the range of -0.27 to -0.58 W/m2 with regional cooling occurring most over the remote oceans.
我们应用全球气候模型ECHAM5/MESSy1-MADE并结合详细的气溶胶和云微物理学，来研究2012年四种近期船舶排放政策情景下航运对对流层气溶胶负荷、云以及辐射收支的影响。我们将一种“无控制”情景与全球硫排放限制及区域减排措施进行了比较。我们发现，如果不采取控制措施，从2002年到2012年，主要跨洋航线附近的近地表硫酸盐含量将增加约10%-20%。将沿海地区200海里范围内（“全球排放控制区”）允许的最大燃料硫（S）含量降至0.5%或0.1%（分别为5000或1000 ppm S），与2002年相比，沿海地区航运产生的近地表硫酸盐含量将显著降低。模型结果还表明，如果氮氧化物（NO(x)）排放量不减少，燃料硫含量的降低会促使气溶胶硝酸盐（NO3）大幅增加，这可能抵消硫排放减少所带来的硫酸盐质量下降的20%。航运对辐射收支的最重要影响与低海平积云的变化有关，这会导致反射率增加和短波云强迫增强。航运产生的直接气溶胶效应较小。我们的研究表明，由于远洋船舶当前燃料硫含量的降低，预计辐射强迫的负效应（降温效应）会减小。2012年航运造成的全球年平均净云强迫在-0.27至-0.58 W/m²范围内，偏远海洋区域的降温最为明显。
