Next Article in Journal
Statistical Applications to Downscale GRACE-Derived Terrestrial Water Storage Data and to Fill Temporal Gaps
Next Article in Special Issue
Multi-View Polarimetric Scattering Cloud Tomography and Retrieval of Droplet Size
Previous Article in Journal
The Sensitivity of Multi-spectral Satellite Sensors to Benthic Habitat Change
Previous Article in Special Issue
Retrieval of Cloud Optical Thickness from Sky-View Camera Images using a Deep Convolutional Neural Network based on Three-Dimensional Radiative Transfer

Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations

Department of Space, Earth and Environment, Microwave and Optical Remote Sensing, Chalmers University of Technology, Chalmersplatsen 4, 41296 Gothenburg, Sweden
Author to whom correspondence should be addressed.
Remote Sens. 2020, 12(3), 531;
Received: 30 December 2019 / Revised: 29 January 2020 / Accepted: 31 January 2020 / Published: 6 February 2020
This study was conducted to quantify the errors prompted by neglecting three-dimensional (3D) effects, i.e., beam-filling and horizontal photon transport effects, at millimeter/sub-millimeter wavelengths. This paper gives an overview of the 3D effects that impact ice cloud retrievals of both current and proposed (Ice Cloud Imager) satellite instruments operating at frequencies of ≈186.3 and ≈668 GHz. The 3D synthetic scenes were generated from two-dimensional (2D) CloudSat (Cloud Satellite) observations over the tropics and mid-latitudes using a stochastic approach. By means of the Atmospheric Radiative Transfer Simulator (ARTS), three radiative transfer simulations were carried out: one 3D, one independent beam approximation (IBA), and one-dimensional (1D). The comparison between the 3D and IBA simulations revealed a small horizontal photon transport effect, with IBA simulations introducing mostly random errors and a slight overestimation (below 1 K). However, performing 1D radiative transfer simulations results in a significant beam-filling effect that increases primarily with frequency, and secondly, with footprint size. For a sensor footprint size of 15 km, the errors induced by neglecting domain heterogeneities yield root mean square errors of up to ≈4 K and ≈13 K at 186.3 GHz and 668 GHz, respectively. However, an instrument operating at the same frequencies, but with a much smaller footprint size, i.e., 6 km, is subject to smaller uncertainties, with a root mean square error of ≈2 K at 186.3 GHz and ≈7.1 K at 668 GHz. When designing future satellite instruments, this effect of footprint size on modeling uncertainties should be considered in the overall error budget. The smallest possible footprint size should be a priority for future sub-millimeter observations in light of these results. View Full-Text
Keywords: 3D effects; mm/sub-mm; Ice Cloud Imager 3D effects; mm/sub-mm; Ice Cloud Imager
Show Figures

Graphical abstract

MDPI and ACS Style

Barlakas, V.; Eriksson, P. Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations. Remote Sens. 2020, 12, 531.

AMA Style

Barlakas V, Eriksson P. Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations. Remote Sensing. 2020; 12(3):531.

Chicago/Turabian Style

Barlakas, Vasileios, and Patrick Eriksson. 2020. "Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations" Remote Sensing 12, no. 3: 531.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop