Atmospheric aerosol hygroscopic growth: approaching trough remote sensing
- Autores: Andrés E. Bedoya
- Directores de la Tesis: Juan Luis Guerrero Rascado (dir. tes.), Carlos David Hoyos Ortiz (codir. tes.)
- Lectura: En la Universidad de Granada ( España ) en 2019
- Idioma: inglés
- ISBN: 9788413062846
- Número de páginas: 218
- Títulos paralelos:
- Crecimiento higroscópico del aerosol atmosférico: aproximación mediante teledetección
- Tribunal Calificador de la Tesis: Henrique Jorge De Melo Barbosa (presid.), Inmaculada Foyo Moreno (secret.), D. Nisperuza (voc.)
- Programa de doctorado: Programa de Doctorado en Física y Ciencias del Espacio por la Universidad de Granada
- Menciones:
- Internacional
- Calificación: Sobresaliente
- Materias:
- Enlaces
- Tesis en acceso abierto en: DIGIBUG
- Resumen
This PhD dissertation focuses on the study of aerosol hygroscopic phenomena under real atmospheric conditions combining active and passive remote sensing measurements together with in situ and ancillary instrumentation. This work provides different methodologies for studying water uptake by atmospheric aerosol particles by using their optical and microphysical properties under changes in relative humidity.
Data acquisition was a hard task because up to three different locations were used. Firstly, data at the Andalusian Institute for Earth System Research (IISTA-CEAMA) in Granada (Spain) were considered from 2012 to 2016, including the data acquired by the SLOPE I (Sierra Nevada Lidar AerOsol Profiling Experiment) field campaign in 2016. Secondly, data at the SIATA-tower station (Sistema de Alerta Temprana de Medellín y el Valle de Aburrá), located in Medellín (Colombia) from a 3.5-year database of continuous measurements of automatic remote sensing, meteorological and in situ instruments were analyzed. Finally, database acquired at the SIRTA observatory (Site Instrumental de Recherche par Télédétection Atmosphérique) located approximately 20 km Southwest of Paris (France), allowed for analyzing 4.5 years of data from different instrumentation (remote sensing, meteorological and in situ instruments).
Active remote sensors involved in this thesis were a multiwavelength Raman lidar, Doppler lidar, and Jenoptik CHM15K, Vaisala CL31 and CL51 ceilometers. On other hand, passive remote sensors such as a Sun photometer, and RPG-HATPRO and MP3000 microwave radiometers were also used. To determine particle concentration, in situ data are taken from PM1, PM2.5, and the Aerosol Chemical Speciation Monitor. Finally, some meteorological sensors were used for retrieving temperature, relative humidity, and wind speed and direction.
In this work, the backscatter coefficient (β) is used to study the hygroscopic growth properties. This optical property can be retrieved by different instruements, either from Raman lidars or ceilometers. In addition, relative humidity was measured together with β obtained from the microwave radiometer and radiosondes launched during specific campaings. Other instrumentation mentioned above was used as ancillary information to this study.
The main goal of this thesis is to investigate the aerosol hygroscopicity growth process in the real atmospheric conditions. The methodology proposed is divided into temporal and vertical evolution frames. The simultaneous increase/decrease of the relative humidity and β in temporal and vertical windows, among other criteria are analyzed. This procedure leads to deeply analyze about 18 cases for vertical evolution methodology and up to 15 cases for temporal evolution. This fact allowed for establishing the database of this phenomenon at three different sites and creating innovative easy-to-apply instrumentation setups. In addition, this work helped to determine the role that organic and inorganic aerosols play in the hygroscopicity growth.
Following the same structure of a research manuscript, chapter 1 is devoted to an overview of this topic. The fundamentals basis are given in chapter 2. Chapter 3 presents the sites and instrumentation involved, focusing the attention on remote sensing instrumentation at all the stations, namely IISTA-CEAMA, SIATA-tower, and SIRTA observatory. The methodologies used in this work are presented in chapter 4, explaining the procedures to perform a temporal and vertical evaluation of the aerosol hygroscopicity under unmodified atmospheric conditions. Chapter 5 presents the results associated to the error characterization of the microwave radiometers at the IISTA-CEAMA and SIATA-tower stations, in order to define trustworthy regions of the temperature and relative humidity profiles. This characterization was performed for all-weather, free-cloud, daytime and night-time conditions to have a better understating of the instrument in terms of its accuracy and precision. Chapter 6 is devoted to an aerosol hygroscopicity growth case evaluated during the SLOPE I field campaign (16/06/2016) at the IISTA-CEAMA station. This case develops one of the methodologies stated as vertical evolution analysis of the hygroscopicity where Raman lidar, Doppler lidar, radiosondes and microwave radiometer are involved. Chapter 7 presents the results obtained under temporal evolution methodology by using relative humidity and wind speed and direction from a 30m-tower combined with attenuated backscatter from a Vaisala ceilometer, together with on-line in situ measurements of aerosol concentration. This 4.5-year study allows for deeply analyzing 8 hygroscopic growth cases at the SIRTA observatory. Chapter 8 makes an evaluation of the vertical and temporal evolution methodologies just by using automatic remote sensors (ceilometers) and microwave radiometers at both the IISTA-CEAMA and SIATA-tower stations. Finally, in chapter 9 are presented the general conclusions and perspectives of the future work. This study leads to analyze up to 18 potential aerosol hygroscopic growth cases between vertical and temporal evaluations at the SIATA-tower station, and six at the IISTA-CEAMA station in the vertical frame.
During this thesis, some data quality assurance tests have been carried out to the multiwavelength Raman lidar system. The measurements with lidar have been performed following the measurement protocols proposed by EARLINET. In order to retrieve optical products, the data- pre-processing have been done with lidar and ceilometer systems and also calibrations to the microwave radiometer were performed to assure the optimal operation. The error propagation involved in optical and hygroscopic properties retrieved has been calculated using the Monte Carlo technique.
The results obtained in this thesis establish a remote sensing database of the hygroscopicity properties, which will have an impact in the future studies about the role of certain aerosol emissions and their interaction with water vapor linked to their effect in the radiative forcing calculations.
