Description
Cloud processes are of particular importance for the evolution of weather and climate, as they regulate the global distribution of precipitation further influencing the hydrological cycle, and affecting the Earth’s radiative budget. Atmospheric aerosol particles can serve as cloud condensation nuclei (CCN) and ice nuclei particles (INP) exerting a large influence in cloud properties. It is widely recognized that many of the limitations in the predictive ability of cutting-edge regional and global climate models stem from incomplete representations of cloud processes, including aerosol-cloud interactions (ACI).
The main goal of the BioCloud campaign is to gain a better understanding of the sources and processes that aerosol particles undergo in the atmosphere to become effective CCN or INP. This will be accomplished using a set of in-situ instrumentation located at a unique high-altitude station in southern Europe, Sierra Nevada Station (37°5'44.17"N, 3°23'12.14"W, 2500 m asl). Combination with remote sensing instrumentation located downslope of Sierra Nevada mountains, will offer additional insight in the aerosol vertical distribution and atmospheric conditions.
Sierra Nevada is the highest mountain range in occidental Europe after the Alps and represents a unique location of snowy regions in semiarid environment. It is located on the southeastern part of the Iberian Peninsula and runs parallel to the Mediterranean coast at about 40 km of distance. Due to its location, intrusions of Saharan dust are very frequent and intense during spring and summer.
The campaign is focused on 1) new particle formation events, the factors that promote these events and their impact in the CCN budget and 2) characterization of Primary Biological Aerosol Particles (PBAPs) and their ability to activate as CCN/INP.
Calendar
June to July 2022.
AGORA instrumentation
In-situ instruments at SNS:
- Cloud condensation nuclei counter (CCN200, DMT): CCN concentrations at varying supersaturations.
- Scanning mobility particle size spectrometers equipped with short and long DMAs for measuring the aerosol number size distribution from Dp 4 nm.
- Aerodynamic particle size spectrometer (APS, TSI) for measuring the aerosol number size distribution in the coarse size range.
- Aethalometer AE33 for measuring BC concentrations at 7 wavelengths
- Rapid-e (Plair) for measuring the scattering pattern and fluorescence of individual particles.
- Aerosol Chemical Speciation Monitor (ToF-ACSM, Aerodyne) for measuring sub-micron non-refractory mass concentrations.
- Off-line sampling for INP analysis using Droplet Freezing Assay technique.
- Off-line PM10 filter samples for chemical characterization
- Off-line sampling of VOCs
- Off-line sampling of pollen particles (Hirst sampler)
- Meteorological instrumentation
- Gas station (Thermo analyzers): NOx, SO2, O3 and PM10
Remote sensing instruments operating at UGR station:
- Multispectral Raman lidar system: vertical distribution of the atmospheric aerosol, in particular profiles of the backscattering and extinction coefficients. In addition, the aerosol depolarization coefficients will be obtained.
- Ceilometer (CHM 15k, Jenoptik), that emits at 1064 nm and allows to know continuously the height of the aerosol and clouds.
- Radar (RPG-FMCW-94-DP): vertical profiles of cloud properties, such as reflectivity, reflectivity spectra, vertical wind speed and depolarization ratio.
- Microwave radiometer (HATPRO G2, RPG): temperature and humidity profilers.
- Photometer solar/lunar (CIMEL CE-318-T): columnar integrated atmospheric aerosol properties. The instruments operate on the AERONET network.