Empirically derived parameterizations of the direct aerosol radiative effect based on ORACLES aircraft observations
-
Published:2021-01-27
Issue:1
Volume:14
Page:567-593
-
ISSN:1867-8548
-
Container-title:Atmospheric Measurement Techniques
-
language:en
-
Short-container-title:Atmos. Meas. Tech.
Author:
Cochrane Sabrina P., Schmidt K. SebastianORCID, Chen HongORCID, Pilewskie Peter, Kittelman Scott, Redemann JensORCID, LeBlanc SamuelORCID, Pistone KristinaORCID, Kacenelenbogen Meloë, Segal Rozenhaimer Michal, Shinozuka Yohei, Flynn Connor, Dobracki Amie, Zuidema PaquitaORCID, Howell Steven, Freitag SteffenORCID, Doherty Sarah
Abstract
Abstract. In this paper, we use observations from the NASA ORACLES
(ObseRvations of CLouds above Aerosols and their intEractionS) aircraft
campaign to develop a framework by way of two parameterizations that
establishes regionally representative relationships between aerosol-cloud
properties and their radiative effects. These relationships rely on new
spectral aerosol property retrievals of the single scattering albedo (SSA)
and asymmetry parameter (ASY). The retrievals capture the natural
variability of the study region as sampled, and both were found to be fairly
narrowly constrained (SSA: 0.83 ± 0.03 in the mid-visible, 532 nm;
ASY: 0.54 ± 0.06 at 532 nm). The spectral retrievals are well suited
for calculating the direct aerosol radiative effect (DARE) since SSA and ASY are tied directly to the irradiance measured in the presence of aerosols – one of the inputs to the spectral DARE. The framework allows for entire campaigns to be generalized into a set of
parameterizations. For a range of solar zenith angles, it links the
broadband DARE to the mid-visible aerosol optical depth (AOD) and the albedo (α) of the underlying scene (either clouds or clear sky) by way of the first parameterization: P(AOD, α). For ORACLES, the
majority of the case-to-case variability of the broadband DARE is
attributable to the dependence on the two driving parameters of P(AOD,
α). A second, extended, parameterization PX(AOD, α, SSA)
explains even more of the case-to-case variability by introducing the
mid-visible SSA as a third parameter. These parameterizations establish a direct link from two or three mid-visible (narrowband) parameters to the broadband DARE, implicitly accounting for the underlying
spectral dependencies of its drivers. They circumvent some of the
assumptions when calculating DARE from satellite products or in a modeling context. For example, the DARE dependence on aerosol microphysical
properties is not explicit in P or PX because the asymmetry parameter varies
too little from case to case to translate into appreciable DARE variability.
While these particular DARE parameterizations only represent the ORACLES
data, they raise the prospect of generalizing the framework to other
regions.
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference53 articles.
1. Anderson, G. P., Shepard, A. C., Kneizys, F. X., James, Chetwynd, H.,
and Eric, P. S.: AFGL atmospheric constituent profiles (0.120 km), Report No. AFGL-TR-86-0110, Air Force Geophysics Lab Hanscom AFB MA, 1986. 2. Boucher, O., Schwartz, S. E., Ackerman, T. P., Anderson, T. L., Bergstrom,
B., Bonnel, B., Chylek, P., Dahlback, A., Fouquart, Y., Fu, Q., Halthore, R.
N., Haywood, J. M., Iversen, T., Kato, S., Kinne, S., Kirkevag, A., Knapp,
K. R., Lacis, A., Laszlo, I., Mishchenko, M. I., Nemesure, S., Ramaswamy,
V., Roberts, D. L., Russell, P., Schlesinger, M. E., Stephens, G. L.,
Wagener, R., Wang, M., Wong, J., and Yang, F.: Intercomparison of models
representing direct shortwave radiative forcing by sulfate aerosols, J.
Geophys. Res.-Atmos., 103, 16979–16998, 1998. 3. Chand, D., Wood, R., Anderson, T. L., Satheesh, S. K., and Charlson, R. J.:
Satellite-derived direct radiative effect of aerosols dependent on cloud
cover, Nat. Geosci., 2, 181–184, 2009. 4. Chowdhary, J., Cairns, B., Mishchenko, M., and Travis, L.: Retrieval of
aerosol properties over the ocean using multispectral and multiangle
photopolarimetric measurements from the Research Scanning Polarimeter,
Geophys. Res. Lett., 28, 243–246, https://doi.org/10.1029/2000GL011783, 2001. 5. Coakley, J. A. and Chylek, P.: The two-stream approximation in radiative transfer: Including the angle of the incident radiation, J. Atmos. Sci., 32, 409–418, https://doi.org/10.1175/1520-0469(1975)032<0409:TTSAIR>2.0.CO;2, 1975.
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|