scholarly journals Significant contrasts in aerosol acidity between China and the United States

2021 ◽  
Vol 21 (10) ◽  
pp. 8341-8356
Author(s):  
Bingqing Zhang ◽  
Huizhong Shen ◽  
Pengfei Liu ◽  
Hongyu Guo ◽  
Yongtao Hu ◽  
...  

Abstract. Aerosol acidity governs several key processes in aerosol physics and chemistry, thus affecting aerosol mass and composition and ultimately climate and human health. Previous studies have reported aerosol pH values separately in China and the United States (USA), implying different aerosol acidity between these two countries. However, there is debate about whether mass concentration or chemical composition is the more important driver of differences in aerosol acidity. A full picture of the pH difference and the underlying mechanisms responsible is hindered by the scarcity of simultaneous measurements of particle composition and gaseous species, especially in China. Here we conduct a comprehensive assessment of aerosol acidity in China and the USA using extended ground-level measurements and regional chemical transport model simulations. We show that aerosols in China are significantly less acidic than in the USA, with pH values 1–2 units higher. Based on a proposed multivariable Taylor series method and a series of sensitivity tests, we identify major factors leading to the pH difference. Compared to the USA, China has much higher aerosol mass concentrations (gas + particle, by a factor of 8.4 on average) and a higher fraction of total ammonia (gas + particle) in the aerosol composition. Our assessment shows that the differences in mass concentrations and chemical composition play equally important roles in driving the aerosol pH difference between China and the USA – increasing the aerosol mass concentrations (by a factor of 8.4) but keeping the relative component contributions the same in the USA as the level in China increases the aerosol pH by ∼ 1.0 units and further shifting the chemical composition from US conditions to China's that are richer in ammonia increases the aerosol pH by ∼ 0.9 units. Therefore, China being both more polluted than the USA and richer in ammonia explains the aerosol pH difference. The difference in aerosol acidity highlighted in the present study implies potential differences in formation mechanisms, physicochemical properties, and toxicity of aerosol particles in these two countries.

2020 ◽  
Author(s):  
Bingqing Zhang ◽  
Huizhong Shen ◽  
Pengfei Liu ◽  
Hongyu Guo ◽  
Yongtao Hu ◽  
...  

Abstract. Aerosol acidity governs several key processes in aerosol physics and chemistry, thus affecting aerosol mass and composition, and ultimately the climate and human health. Previous studies have reported the aerosol pH separately in China and the United States, implying a different aerosol acidity between these two countries. However, underlying mechanisms responsible for the pH difference are not fully understood, limited by the scarcity of simultaneous measurements of aerosol composition and gas species, especially in China. Here we conduct a comprehensive assessment of the aerosol acidity in China and the United States, using extended ground-level measurements and regional chemical transport model simulations. We show aerosol in China is significantly less acidic than that in the United States, with pH values 1–2 units higher. Based on a multivariable Taylor Series method and a series of sensitivity tests, we identify several major factors leading to the pH difference. Compared to the United States, aerosols in China are generally in total ammonia (TNH3 = NH4+ + NH3) rich conditions where particle phase ammonium (NH4+) concentrations are adequate enough to nearly neutralize major acidic inorganic anions such as sulfate, nitrate, and chloride, leading to a higher aerosol pH. Higher relative availability of the stronger acidic component, sulfate, compared with the weaker acidic component, total nitrate (TNO3 = NO3− + HNO3), also contributes to the lower aerosol pH in the United States. As a response to higher aerosol pH, the higher nitrate to sulfate molar ratios in China indicates a nitrate-rich condition, further leading to higher aerosol water uptake which will continually promote nitrate aerosol formation. Considering the historical emissions trends, the difference in aerosol acidity between these two countries is expected to continue as SO2 and NOx emissions are further controlled. The differences in aerosol acidity highlight in the present study imply potential differences in formation mechanisms, physicochemical properties, and toxicity of aerosol particles between China and the United States.


2007 ◽  
Vol 41 (35) ◽  
pp. 7389-7400 ◽  
Author(s):  
Rokjin J. Park ◽  
Daniel J. Jacob ◽  
Jennifer A. Logan

2015 ◽  
Vol 15 (18) ◽  
pp. 10669-10685 ◽  
Author(s):  
H. M. Allen ◽  
D. C. Draper ◽  
B. R. Ayres ◽  
A. Ault ◽  
A. Bondy ◽  
...  

Abstract. Inorganic aerosol composition was measured in the southeastern United States, a region that exhibits high aerosol mass loading during the summer, as part of the 2013 Southern Oxidant and Aerosol Study (SOAS) campaign. Measurements using a Monitor for AeRosols and GAses (MARGA) revealed two periods of high aerosol nitrate (NO3−) concentrations during the campaign. These periods of high nitrate were correlated with increased concentrations of supermicron crustal and sea spray aerosol species, particularly Na+ and Ca2+, and with a shift towards aerosol with larger (1 to 2.5 μm) diameters. We suggest this nitrate aerosol forms by multiphase reactions of HNO3 and particles, reactions that are facilitated by transport of crustal dust and sea spray aerosol from a source within the United States. The observed high aerosol acidity prevents the formation of NH4NO3, the inorganic nitrogen species often dominant in fine-mode aerosol at higher pH. Calculation of the rate of the heterogeneous uptake of HNO3 on mineral aerosol supports the conclusion that aerosol NO3− is produced primarily by this process, and is likely limited by the availability of mineral cation-containing aerosol surface area. Modeling of NO3− and HNO3 by thermodynamic equilibrium models (ISORROPIA II and E-AIM) reveals the importance of including mineral cations in the southeastern United States to accurately balance ion species and predict gas–aerosol phase partitioning.


2004 ◽  
Vol 6 (1) ◽  
pp. 75-92 ◽  
Author(s):  
James E. Goggin

Interest in the fate of the German psychoanalysts who had to flee Hitler's Germany and find refuge in a new nation, such as the United States, has increased. The ‘émigré research’ shows that several themes recur: (1) the theme of ‘loss’ of one's culture, homeland, language, and family; and (2) the ambiva-lent welcome these émigrés received in their new country. We describe the political-social-cultural context that existed in the United States during the 1930s, 1940s and 1950s. Documentary evidence found in the FBI files of three émigré psychoanalysts, Clara Happel, Martin Grotjahn, and Otto Fenichel, are then presented in combination with other source material. This provides a provisional impression of how each of these three individuals experienced their emigration. As such, it gives us elements of a history. The FBI documents suggest that the American atmosphere of political insecurity and fear-based ethnocentric nationalism may have reinforced their old fears of National Socialism, and contributed to their inclination to inhibit or seal off parts of them-selves and their personal histories in order to adapt to their new home and become Americanized. They abandoned the rich social, cultural, political tradition that was part of European psychoanalysis. Finally, we look at these elements of a history in order to ask a larger question about the appropriate balance between a liberal democratic government's right to protect itself from internal and external threats on the one hand, or crossover into the blatant invasion of civil rights and due process on the other.


2020 ◽  
Vol 2 (4) ◽  
pp. 32-54
Author(s):  
Silvia Spitta

Sandra Ramos (b. 1969) is one of the few artists to reflect critically on both sides of the Cuban di-lemma, fully embodying the etymological origins of the word in ancient Greek: di-, meaning twice, and lemma, denoting a form of argument involving a choice between equally unfavorable alternatives. Throughout her works she shines a light on the dilemmas faced by Cubans whether in Cuba or the United States, underlining the bad personal and political choices people face in both countries. During the hard 1990s, while still in Havana, the artist focused on the traumatic one-way journey into exile by thousands, as well as the experience of profound abandonment experienced by those who were left behind on the island. Today she lives in Miami and operates a studio there as well as one in Havana. Her initial disorientation in the USA has morphed into an acerbic representation and critique of the current administration and a deep concern with the environmental collapse we face. A buffoonlike Trumpito has joined el Bobo de Abela and Liborio in her gallery of comic characters derived from the rich Cuban graphic arts tradition where she was formed. While Cuba is now represented as a rotten cake with menacing flies hovering over it ready to pounce, a bombastic Trumpito marches across the world stage, trampling everything underfoot, a dollar sign for a face.


Author(s):  
Attarid Awadh Abdulhameed

Ukrainia Remains of huge importance to Russian Strategy because of its Strategic importance. For being a privileged Postion in new Eurasia, without its existence there would be no logical resons for eastward Expansion by European Powers.  As well as in Connection with the progress of Ukrainian is no less important for the USA (VSD, NDI, CIA, or pentagon) and the European Union with all organs, and this is announced by John Kerry. There has always ben Russian Fear and Fear of any move by NATO or USA in the area that it poses a threat to  Russians national Security and its independent role and in funence  on its forces especially the Navy Forces. There for, the Crisis manyement was not Zero sum game, there are gains and offset losses, but Russia does not accept this and want a Zero Sun game because the USA. And European exteance is a Foot hold in Regin Which Russian sees as a threat to its national security and want to monopolize control in the strategic Qirim.


Author(s):  
Halyna Shchyhelska

2018 marks the 100th anniversary of the proclamation of Ukrainian independence. OnJanuary 22, 1918, the Ukrainian People’s Republic proclaimed its independence by adopting the IV Universal of the Ukrainian Central Rada, although this significant event was «wiped out» from the public consciousness on the territory of Ukraine during the years of the Soviet totalitarian regime. At the same time, January 22 was a crucial event for the Ukrainian diaspora in the USA. This article examines how American Ukrainians interacted with the USA Government institutions regarding the celebration and recognition of the Ukrainian Independence day on January 22. The attention is focused on the activities of ethnic Ukrainians in the United States, directed at the organization of the special celebration of the Ukrainian Independence anniversaries in the US Congress and cities. Drawing from the diaspora press and Congressional Records, this article argues that many members of Congress participated in the observed celebration and expressed kind feelings to the Ukrainian people, recognised their fight for freedom, during the House of Representatives and Senate sessions. Several Congressmen submitted the resolutions in the US Congress urging the President of United States to designate January 22 as «Ukrainian lndependence Day». January 22 was proclaimed Ukrainian Day by the governors of fifteen States and mayors of many cities. Keywords: January 22, Ukrainian independence day, Ukrainian diaspora, USA, interaction, Congress


2018 ◽  
Vol 10 (2) ◽  
pp. 107
Author(s):  
John H. Penn

<span>Microscale Chemistry has become the method of choice for the teaching laboratories in the United States. This introspective look at the development of microscale Chemistry details the advantages prornised by microscale Chemistry during the early developmental phase of microscale in the United States. These advantages are then compared to the current usage of microscale. This comparison is designed to highlight areas for potential development of the field.</span>


1994 ◽  
Vol 21 (1) ◽  
pp. 189-213
Author(s):  
Michael P. Schoderbek

This paper examines the early accounting practices that were used to administer the United States' national land system. These practices are of significance because they provide insights on early governmental accounting and they facilitated an orderly settlement of the western territories. The analysis focuses on the record-keeping and control practices that were developed to meet the provisions of the Land Act of 1800 and to account for land office transactions. These accounting procedures were extracted from the correspondence between the Department of the Treasury and the various land officers.


Sign in / Sign up

Export Citation Format

Share Document