d30d324b-87b5-450a-a5ab-0410754bce5c eng Ev-K2-CNR +39 035 3230511 +39 035 3230551 Via San Bernardino 145 Bergamo BG 24126 Italy metadata@evk2cnr.org http://www.evk2cnr.org/ 2012-03-19T16:52:46 ISO 19115:2003/19139 1.0 High frequency new particle formation in the Himalayas 2008-10-14T00:00:00 Proceedings of the National Academy of Sciences of the United States of America volume 105 n.41 Page 15666 –15671 Proceedings of the National Academy of Sciences of the United States of America volume 105 0027-8424 Rising air pollution levels in South Asia will have worldwide environmental consequences. Transport of pollutants from the densely populated regions of India, Pakistan, China, and Nepal to the Himalayas may lead to substantial radiative forcing in South Asia with potential effects on the monsoon circulation and, hence, on regional climate and hydrological cycles, as well as to dramatic impacts on glacier retreat. An improved description of particulate sources is needed to constrain the simulation of future regional climate changes. Here, the first evidence of very frequent new particle formation events occurring up to high altitudes is presented. A 16-month record of aerosol size distribution from the Nepal Climate Observatory at Pyramid (Nepal, 5,079 m above sea level), the highest atmospheric research station, is shown. Aerosol concentrations are driven by intense ultrafine particle events occurring on >35% of the days at the interface between clean tropospheric air and the more polluted air rising from the valleys. During a pilot study, we observed a significant increase of ion cluster concentrations with the onset of new particle formation events. The ion clusters rapidly grew to a 10-nm size within a few hours, confirming, thus, that in situ nucleation takes place up to high altitudes. The initiation of the new particle events coincides with the shift from free tropospheric downslope winds to thermal upslope winds from the valley in the morning hours. The new particle formation events represent a very significant additional source of particles possibly injected into the free troposphere by thermal winds. The Proceedings of the National Academy of Sciences USA (PNAS) publishes research reports, commentaries, perspectives, and colloquium papers. In accordance with the guiding principles established by George Ellery Hale in 1914, PNAS publishes brief first announcements of Academy members' and foreign associates' (hereafter referred to as members) more important contributions to research and of work that appears to a member to be of particular importance. PNAS is a general science journal and all papers should be intelligible to a broad scientific audience. Proceedings of the National Academy of Sciences of the United States of America +1 2023342679 +1 2023342739 700 11th Street, NW Washington DC 20001 United States of America pnas@nas.edu www.pnas.org WWW:LINK-1.0-http--related Hervé Venzac Blaise Pascal University,CNRS +33 473407678 +33 473405136 24, avenue des Landais Aubière Cedex 63177 France h.venzac@opgc.univ-bpclermont.fr www.univ-bpclermont.fr Karine Sellegri Blaise Pascal University, CNRS +33 473407394 +33 473405136 24, avenue des Landais Aubière Cedex 63177 France K.Sellegri@opgc.univ-bpclermont.fr www.univ-bpclermont.fr Paolo Laj CNRS Laboratory of Meteorology Physics - Laboratory of Glaciology +33 685628874 +33 473405132 24,Avenue des Landais Aubiere Cedex 63177 France aj@lgge.obs.ujf-grenoble.fr http://wwwobs.univ-bpclermont.fr/ Paolo Villani Blaise Pascal University,CNRS +33 473407678 +33 473405136 24,Avenue des Landais Aubiere Cedex 63177 France p.villani@opgc.univ-bpclermont.fr www.univ-bpclermont.fr Paolo Bonasoni Institute of Atmospheric Sciences and Climate (ISAC) - CNR +39 0516399590 +39 0516399652 Via Gobetti,101 Bologna BO 40129 Italy p.bonasoni@isac.cnr.it www.isac.cnr.it Angela Marinoni Institute of Atmospheric Sciences and Climate (ISAC) - CNR +39 0516399597 +39 0516399652 Via Gobetti,101 Bologna BO 40129 Italy a.marinoni@isac.cnr.it www.isac.cnr.it Paolo Cristofanelli Institute of Atmospheric Sciences and Climate (ISAC) - CNR +39 0516399597 +39 0516399652 Via Gobetti,101 Bologna BO 40129 Italy p.cristofanelli@isac.cnr.it www.isac.cnr.it Francescopiero Calzolari Institute of Atmospheric Sciences and Climate (ISAC) - CNR +39 0516399582 Via Gobetti,101 Bologna BO 40129 Italy F.Calzolari@isac.cnr.it www.isac.cnr.it Sandro Fuzzi Institute of Atmospheric Sciences and Climate (ISAC) - CNR +39 0516399559 +39 0516399647 Via Gobetti,101 Bologna BO 40129 Italy S.Fuzzi@isac.cnr.it www.isac.cnr.it Stefano Decesari Institute of Atmospheric Sciences and Climate (ISAC) - CNR +39 0516399560 Via Gobetti,101 Bologna BO 40129 Italy S.Decesari@isac.cnr.it www.isac.cnr.it Maria Cristina Facchini Institute of Atmospheric Sciences and Climate (ISAC) - CNR +39 0516399563 Via Gobetti,101 Bologna BO 40129 Italy mc.facchini@isac.cnr.it www.isac.cnr.it Elisa Vuillermoz Ev-K2-CNR +39 0353230513 +39 0353230551 Via San Bernardino, 145 Bergamo BG 24126 Italy elisa.vuillermoz@evk2cnr.org http://www.evk2cnr.org Gian Pietro Verza Ev-K2-CNR Via San Bernardino, 145 Bergamo BG 24126 Italy gianpietro.verza@evk2cnr.org http://www.evk2cnr.org WWW:LINK-1.0-http--partners https://geoportal.mountaingenius.org/geonetwork/srv/eng/resources.get?uuid=d30d324b-87b5-450a-a5ab-0410754bce5c&fname=mountain_witness__s.png thumbnail png Nepal Himalaya South Asia air pollution high altitudes aerosol aerosol size distribution monsoon circulation regional climate hydrological cycles particle formation nucleation free troposphere SHARE GAW ABC eng climatologyMeteorologyAtmosphere geoscientificInformation environment 57.44 100.67 -2.2 38.78 http://www.pnas.org/content/105/41/15666 WWW:LINK-1.0-http--related Abstract:"High frequency new particle formation in the Himalayas." https://geoportal.mountaingenius.org/webapp/srv/en/resources.get?id=28451&fname=PNAS-2008-Venzac-15666-71.pdf&access=private WWW:DOWNLOAD-1.0-http--download PNAS-2008-Venzac-15666-71.pdf Full Text(pdf):"High frequency new particle formation in the Himalayas." “High frequency new particle formation in the Himalayas.” Hervé Venzac, Karine Sellegri, Paolo Laj, Paolo Villani, Paolo Bonasoni, Angela Marinoni, Paolo Cristofanelli, Francescopiero Calzolari, Sandro Fuzzi, Stefano Decesari, Maria-Cristina Facchini, Elisa Vuillermoz, and Gian Pietro Verza. PNAS(Proceedings of the National Academy of Sciences of the United States of America vol.105 no.41 Page 15666 –15671.