干旱区生态环境知识资源中心(Arid): Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems

Arid

DOI	10.5194/acp-20-12223-2020
	Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems
	Shah, Viral; Jacob, Daniel J.; Moch, Jonathan M.; Wang, Xuan; Zhai, Shixian
通讯作者	Shah, V
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
ISSN	1680-7316
EISSN	1680-7324
出版年	2020
卷号	20 期号:20 页码:12223-12245
英文摘要	Cloud water acidity affects the atmospheric chemistry of sulfate and organic aerosol formation, halogen radical cycling, and trace metal speciation. Precipitation acidity including post-depositional inputs adversely affects soil and freshwater ecosystems. Here, we use the GEOS-Chem model of atmospheric chemistry to simulate the global distributions of cloud water and precipitation acidity as well as the total acid inputs to ecosystems from wet deposition. The model accounts for strong acids (H2SO4, HNO3, and HCl), weak acids (HCOOH, CH3COOH, CO2, and SO2), and weak bases (NH3 as well as dust and sea salt aerosol alkalinity). We compile a global data set of cloud water pH measurements for comparison with the model. The global mean observed cloud water pH is 5.2 +/- 0.9, compared to 5.0 +/- 0.8 in the model, with a range from 3 to 8 depending on the region. The lowest values are over East Asia, and the highest values are over deserts. Cloud water pH over East Asia is low because of large acid inputs (H2SO4 and HNO3), despite NH3 and dust neutralizing 70 % of these inputs. Cloud water pH is typically 4-5 over the US and Europe. Carboxylic acids account for less than 25 % of cloud water H+ in the Northern Hemisphere on an annual basis but 25 %-50 % in the Southern Hemisphere and over 50 % in the southern tropical continents, where they push the cloud water pH below 4.5. Anthropogenic emissions of SO2 and NOx (precursors of H2SO4 and HNO3) are decreasing at northern midlatitudes, but the effect on cloud water pH is strongly buffered by NH4+ and carboxylic acids. The global mean precipitation pH is 5.5 in GEOS-Chem, which is higher than the cloud water pH because of dilution and below-cloud scavenging of NH3 and dust. GEOS-Chem successfully reproduces the annual mean precipitation pH observations in North America, Europe, and eastern Asia. Carboxylic acids, which are undetected in routine observations due to biodegradation, lower the annual mean precipitation pH in these areas by 0.2 units. The acid wet deposition flux to terrestrial ecosystems taking into account the acidifying potential of NO3- and NH4+ in N-saturated ecosystems exceeds 50 meq m(-2 )a(-1) in East Asia and the Americas, which would affect sensitive ecosystems. NH4+ is the dominant acidifying species in wet deposition, contributing 41 % of the global acid flux to continents under N-saturated conditions.
类型	Article
语种	英语
开放获取类型	gold, Green Submitted
收录类别	SCI-E
WOS记录号	WOS:000582673900003
WOS关键词	CHEMICAL-TRANSPORT MODEL ; SEA-SALT AEROSOLS ; 2011 E-PEACE ; WET DEPOSITION ; ORGANIC-ACIDS ; UNITED-STATES ; AQUEOUS-PHASE ; AIR-QUALITY ; FOG WATER ; ANTHROPOGENIC EMISSIONS
WOS类目	Environmental Sciences ; Meteorology & Atmospheric Sciences
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/327143
作者单位	[Shah, Viral; Jacob, Daniel J.; Wang, Xuan; Zhai, Shixian] Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Cambridge, MA 02138 USA; [Jacob, Daniel J.; Moch, Jonathan M.] Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St, Cambridge, MA 02138 USA; [Wang, Xuan] City Univ Hong Kong, Sch Energy & Environm, Hong Kong, Peoples R China
推荐引用方式 GB/T 7714	Shah, Viral,Jacob, Daniel J.,Moch, Jonathan M.,et al. Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems[J],2020,20(20):12223-12245.
APA	Shah, Viral,Jacob, Daniel J.,Moch, Jonathan M.,Wang, Xuan,&Zhai, Shixian.(2020).Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(20),12223-12245.
MLA	Shah, Viral,et al."Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.20(2020):12223-12245.