Near-surface and columnar measurements with a micro pulse lidar of atmospheric pollen in Barcelona, Spain
Michaël Sicard1,2,Rebeca Izquierdo3,Marta Alarcón3,Jordina Belmonte4,5,Adolfo Comerón1,and José Maria Baldasano6,7Michaël Sicard et al.Michaël Sicard1,2,Rebeca Izquierdo3,Marta Alarcón3,Jordina Belmonte4,5,Adolfo Comerón1,and José Maria Baldasano6,7
1Remote Sensing Laboratory, Universitat Politècnica de Catalunya,
Barcelona, Spain
2Ciències i Tecnologies de l'Espai – Centre de Recerca de
l'Aeronàutica i de l'Espai/Institut d'Estudis Espacials de Catalunya
(CTE-CRAE/IEEC), Universitat Politècnica de Catalunya, Barcelona,
Spain
3Departament de Física, Universitat Politècnica de Catalunya
(UPC), c/Urgell 187, 08036 Barcelona, Spain
4Departament de Biologia Animal, Biologia Vegetal i Ecologia,
Universitat Autònoma de Barcelona (UAB). Edifici C, 08193 Bellaterra,
Spain
5Institut de Ciencia i Tecnología Ambientals (ICTA), Universitat
Autònoma de Barcelona (UAB), Edifici Z, 08193 Bellaterra, Spain
6Earth Sciences Department, Barcelona Supercomputing Center – Centro
Nacional de Supercomputación, Barcelona, Spain
7Environmental Modeling Laboratory, Technical University of Catalonia,
Barcelona, Spain
1Remote Sensing Laboratory, Universitat Politècnica de Catalunya,
Barcelona, Spain
2Ciències i Tecnologies de l'Espai – Centre de Recerca de
l'Aeronàutica i de l'Espai/Institut d'Estudis Espacials de Catalunya
(CTE-CRAE/IEEC), Universitat Politècnica de Catalunya, Barcelona,
Spain
3Departament de Física, Universitat Politècnica de Catalunya
(UPC), c/Urgell 187, 08036 Barcelona, Spain
4Departament de Biologia Animal, Biologia Vegetal i Ecologia,
Universitat Autònoma de Barcelona (UAB). Edifici C, 08193 Bellaterra,
Spain
5Institut de Ciencia i Tecnología Ambientals (ICTA), Universitat
Autònoma de Barcelona (UAB), Edifici Z, 08193 Bellaterra, Spain
6Earth Sciences Department, Barcelona Supercomputing Center – Centro
Nacional de Supercomputación, Barcelona, Spain
7Environmental Modeling Laboratory, Technical University of Catalonia,
Barcelona, Spain
Received: 11 Mar 2016 – Discussion started: 16 Mar 2016 – Revised: 18 May 2016 – Accepted: 21 May 2016 – Published: 06 Jun 2016
Abstract. We present for the first time continuous hourly measurements of pollen near-surface concentration and lidar-derived profiles of particle backscatter coefficients and of volume and particle depolarization ratios during a 5-day pollination event observed in Barcelona, Spain, between 27 and 31 March 2015. Daily average concentrations ranged from 1082 to 2830 pollen m−3. Platanus and Pinus pollen types represented together more than 80 % of the total pollen. Maximum hourly pollen concentrations of 4700 and 1200 m−3 were found for Platanus and Pinus, respectively. Every day a clear diurnal cycle caused by the vertical transport of the airborne pollen was visible on the lidar-derived profiles with maxima usually reached between 12:00 and 15:00 UT. A method based on the lidar polarization capabilities was used to retrieve the contribution of the pollen to the total aerosol optical depth (AOD). On average the diurnal (09:00–17:00 UT) pollen AOD was 0.05, which represented 29 % of the total AOD. Maximum values of the pollen AOD and its contribution to the total AOD reached 0.12 and 78 %, respectively. The diurnal means of the volume and particle depolarization ratios in the pollen plume were 0.08 and 0.14, with hourly maxima of 0.18 and 0.33, respectively. The diurnal mean of the height of the pollen plume was found at 1.24 km with maxima varying in the range of 1.47–1.78 km. A correlation study is performed (1) between the depolarization ratios and the pollen near-surface concentration to evaluate the ability of the former parameter to monitor pollen release and (2) between the depolarization ratios as well as pollen AOD and surface downward solar fluxes, which cause the atmospheric turbulences responsible for the particle vertical motion, to examine the dependency of the depolarization ratios and the pollen AOD upon solar fluxes. For the volume depolarization ratio the first correlation study yields to correlation coefficients ranging 0.00–0.81 and the second to correlation coefficients ranging 0.49–0.86.
For the first time the concentration of pollen grains was measured on an hourly basis during a 5-day pollination event in Barcelona, Spain, while at the same time the pollen dispersion in the atmosphere was measured also continuously by a lidar (laser radar) system. The intensity of the pollen dispersion revealed to be strongly correlated with the solar radiation reaching the Earth.
For the first time the concentration of pollen grains was measured on an hourly basis during a...