Evaluating Cloud Number Concentration Retrievals in Marine Stratocumulus with ACE-ENA Measurements
Authors
Damao Zhang — Pacific Northwest National Laboratory
Fan Yang — Brookhaven National Laboratory
Edward Luke — Brookhaven National Laboratory
Pavlos Kollias — Stony Brook University
Andrew M. Vogelmann — Brookhaven National Laboratory
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Category
Warm low clouds, including aerosol interactions
Description
Marine stratocumulus clouds play an important role in earth’s radiation budget. Changes in aerosol concentration and chemical composition affect cloud number concentration (Nd) and droplet size, and therefore affect cloud albedo and precipitation efficiency. Retrieving Nd is of the central interest for quantitatively studying aerosol-cloud interactions. Algorithms for retrieving Nd in stratocumulus with remote sensing measurements have been employed using combined radar, lidar, and radiometer data (Martucci and O'Dowd 2011; Rémillard et al., 2013; Rusli et al., 2017; Snider et al., 2017). However, evaluations of retrieved Nd with in situ measurements are still sparse. The ARM Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) field campaign provides a unique dataset for such evaluations through the collocation of aircraft in situ measurements and ground-based remote sensing measurements at the ENA ARM Facility. Preliminary comparisons of retrieved Nd in a non-drizzling stratocumulus with in situ measurements show good agreement. We will further evaluate the retrieved Nd for both drizzling and non-drizzling stratocumulus and under different background aerosol conditions using data from the two ACE-ENA intensive operational periods.
Reference:
Martucci, G. and O'Dowd, C. D.: Ground-based retrieval of continental and marine warm cloud microphysics, Atmos. Meas. Tech., 4, 2749-2765, https://doi.org/10.5194/amt-4-2749-2011, 2011.
Rémillard, J., Kollias, P., and Szyrmer, W.: Radar-radiometer retrievals of cloud number concentration and dispersion parameter in nondrizzling marine stratocumulus, Atmos. Meas. Tech., 6, 1817-1828, https://doi.org/10.5194/amt-6-1817-2013, 2013.
Rusli, S. P., Donovan, D. P., and Russchenberg, H. W. J.: Simultaneous and synergistic profiling of cloud and drizzle properties using ground-based observations, Atmos. Meas. Tech., 10, 4777-4803, https://doi.org/10.5194/amt-10-4777-2017, 2017.
Snider, J.R., D. Leon, and Z. Wang, 2017: Droplet Concentration and Spectral Broadening in Southeast Pacific Stratocumulus Clouds. J. Atmos. Sci., 74, 719–749,https://doi.org/10.1175/JAS-D-16-0043.1
