title: High black carbon and ozone concentrations during pollution transport in the Himalayas: five years of continuous observations at NCO-P global GAW station.
abstract: To study the influence of polluted air-mass transport carrying ozone (O3) and black carbon (BC) in the high Himalayas, since March 2006 the Nepal Climate Observatory at Pyramid (NCO-P) GAW-WMO global station (Nepal, 5079 m a.s.l.) is operative. During the first 5-year measurements, the O3 and BC concentrations have shown a mean value of 48 +/- 12 ppb (+/- standard deviation) and 208 +/- 374 ng/m3, respectively. Both O3 and BC showed well defined seasonal cycles with maxima during pre-monsoon (O3: 61.3 +/- 7.7 ppbV; BC: 444 +/- 433 ng/m3) and minima during the summer monsoon (O3: 40.1 +/- 12.4 ppbV; BC: 64 +/- 101 ng/m3). The analysis of the days characterised by the presence of a significant BC increase with respect to the typical seasonal cycle identified 156 days affected by "acute" pollution events, corresponding to 9.1% of the entire data-set. Such events mostly occur in the pre-monsoon period, when the O3 diurnal variability is strongly related to the transport of polluted air-mass rich on BC. On average, these "acute" pollution events were characterised by dramatic increases of BC (352%) and O3 (29%) levels compared with the remaining days.
authors: Institute for Atmospheric Sciences and Climate, National Research Council of Italy, via Gobetti 101, 40129 Bologna, Italy. a.marinoni@isac.cnr.it
authors: A
authors: A
authors: Marinoni
authors: Institute for Atmospheric Sciences and Climate, National Research Council of Italy, via Gobetti 101, 40129 Bologna, Italy.
authors: P
authors: P
authors: Cristofanelli
authors: Laboratoire de Glaciologie et Géophysique de l'Environnement, Université Grenoble 1, CNRS, Saint-Martin d'Hères, France.
authors: P
authors: P
authors: Laj
authors: Institute for Atmospheric Sciences and Climate, National Research Council of Italy, via Gobetti 101, 40129 Bologna, Italy.
authors: R
authors: R
authors: Duchi
authors: Institute for Atmospheric Sciences and Climate, National Research Council of Italy, via Gobetti 101, 40129 Bologna, Italy.
authors: D
authors: D
authors: Putero
authors: Institute for Atmospheric Sciences and Climate, National Research Council of Italy, via Gobetti 101, 40129 Bologna, Italy.
authors: F
authors: F
authors: Calzolari
authors: Institute for Atmospheric Sciences and Climate, National Research Council of Italy, via Gobetti 101, 40129 Bologna, Italy.
authors: T C
authors: TC
authors: Landi
authors: EV-K2-CNR Committee, Bergamo, Italy.
authors: E
authors: E
authors: Vuillermoz
authors: Urbino University, DiSBeE Urbino, Italy.
authors: M
authors: M
authors: Maione
authors: Institute for Atmospheric Sciences and Climate, National Research Council of Italy, via Gobetti 101, 40129 Bologna, Italy.
authors: P
authors: P
authors: Bonasoni
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002244:Carbon / Q000032:analysis*; D009390:Nepal; D010126:Ozone / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D010126:Ozone; D002244:Carbon