Potential of polarization lidar to provide profiles of CCN- and INP-relevant aerosol parameters

Abstract

Abstract. We investigate the potential of polarization lidar to provide vertical profiles of aerosol parameters from which cloud condensation nucleus (CCN) and ice nucleating particle (INP) number concentrations can be estimated. We show that height profiles of particle number concentrations n 50,dry considering dry aerosol particles with radius > 50 nm (reservoir of CCN in the case of marine and continental non-desert aerosols), n 100,dry (particles with dry radius > 100 nm, reservoir of desert dust CCN), and of n 250,dry (particles with dry radius > 250 nm, reservoir of favorable INP), as well as profiles of the particle surface area concentration s dry (used in INP parameterizations) can be retrieved from lidar-derived aerosol extinction coefficients σ with relative uncertainties of a factor of 1.5-2 in the case of n 50,dry and n 100,dry and of about 25-50 % in the case of n 250,dry and s dry . Of key importance is the potential of polarization lidar to distinguish and separate the optical properties of desert aerosols from non-desert aerosol such as continental and marine particles. We investigate the relationship between σ , measured at ambient atmospheric conditions, and n 50,dry for marine and continental aerosols, n 100,dry for desert dust particles, and n 250,dry and s dry for three aerosol types (desert, non-desert continental, marine) and for the main lidar wavelengths of 355, 532, and 1064 nm. Our study is based on multiyear Aerosol Robotic Network (AERONET) photometer observations of aerosol optical thickness and column-integrated particle size distribution at Leipzig, Germany, and Limassol, Cyprus, which cover all realistic aerosol mixtures. We further include AERONET data from field campaigns in Morocco, Cabo Verde, and Barbados, which provide pure dust and pure marine aerosol scenarios. By means of a simple CCN parameterization (with n 50,dry or n 100,dry as input) and available INP parameterization schemes (with n 250,dry and s dry as input) we finally compute profiles of the CCN-relevant particle number concentration n CCN and the INP number concentration n INP . We apply the method to a lidar observation of a heavy dust outbreak crossing Cyprus and a case dominated by continental aerosol pollution.

Potential of polarization/Raman lidar to separate fine dust, coarse dust, maritime, and anthropogenic aerosol profiles

“…Furthermore, we used 7.5 years of data from the AERONET station at Ragged Point, Barbados (Prospero and Mayol-Bracero, 2013), to study the correlation between the aerosol extinction coefficient and volume concentration for pure marine conditions. An overview of the observational periods and amount of available data for the analyzed different aerosol conditions with focus on the three defined aerosol types can be found in Table 1 in Mamouri and Ansmann (2016). More details of these AERONET stations are given on the AERONET web page (http://aeronet.gsfc.nasa.gov).…”

“…5 based on longterm AERONET sun photometer observations at Limassol (Cyprus), Leipzig (Germany), and Ragged Point (Barbados), as well as on measurements during dedicated field campaigns such as SAMUM-1 (Morocco, 2006), SAMUM-2 (Cabo Verde, 2008), and SALTRACE (Barbados, 2013(Barbados, -2014AERONET, 2016). The study makes use of the same AERONET data sets for desert, marine, and polluted continental sites as described in detail already by Mamouri and Ansmann (2016) (Nisantzi et al, 2014(Nisantzi et al, , 2015 are available for our studies. Aerosol mixtures of anthropogenic haze, biomass-burning smoke, soil and road dust, and marine particles as well as strong dust outbreaks from Middle Eastern deserts and the Sahara frequently occur over Cyprus (Nisantzi et al, 2015).…”

“…We identified nine cases of clean marine conditions in the 4-year Limassol AERONET data sets. Further details of the selection criteria, which were applied to sort the individual observations into desert dust, anthropogenic pollution, and marine aerosol classes, can be found in Mamouri and Ansmann (2016).…”

“…We performed the AERONET correlation study also separately for all three laser wavelengths but present the results for the mostly used lidar wavelength of 532 nm only. As shown in Mamouri and Ansmann (2016), the particle volume concentration v is derived from the respective column volume concentrations and the extinction coefficient σ is computed from the available AOT values. Interpolation within the measured AOT spectrum yielded the σ values for the laser wavelengths of 355 and 532 nm.…”

Separation of the optical and mass features of particle components in different aerosol mixtures by using POLIPHON retrievals in synergy with continuous polarized Micro-Pulse Lidar (P-MPL) measurements

“…Very recently, this method, known as the POlarization-LIdar PHOtometer Networking method (POLIPHON), has been refined by Mamouri and Ansmann (2014) to retrieve up to three aerosol components, such as fine and coarse dust and non-dust particles. POLIPHON is also the basis of the retrieval of ice nuclei number concentration in desert dust layers (Mamouri and Ansmann, 2015) and cloud condensation nucleus number concentration (Mamouri and Ansmann, 2016). In addition, a similar method is used for separating aerosol mixtures in HSRL systems (Burton et al, 2012(Burton et al, , 2014.…”