Efficient radiative transfer model for thermal infrared brightness temperature simulation in cloudy atmospheres

Area of Science:

• Atmospheric Science
• Remote Sensing
• Radiative Transfer Theory

Background:

• Accurate simulation of thermal infrared brightness temperatures is crucial for satellite remote sensing.
• Existing radiative transfer models can be computationally intensive, limiting real-time applications.

Purpose of the Study:

• To develop an efficient radiative transfer model (ERTM) for simulating AHI thermal infrared brightness temperatures.
• To evaluate the accuracy and computational efficiency of the developed ERTM.

Main Methods:

• Incorporation of an alternate mapping correlated k-distribution (AMCKD) scheme for gaseous absorption.
• Parameterization of cloud optical properties using effective length for ice clouds and effective radius for water clouds.
• Extension of the four-stream discrete ordinates method (4DDA) to calculate zenith angle-dependent radiative intensity.

Main Results:

• The ERTM achieved a maximum root mean square error (RMSE) of 0.21K for AHI channel B16 under standard atmospheric profiles.
• ERTM demonstrated a computational efficiency approximately five orders of magnitude higher than benchmark models (DISORT and LBLRTM).
• Simulated brightness temperatures showed high consistency with rigorous results and AHI observations during Typhoon Mujigae.

Conclusions:

• The developed ERTM is an efficient and accurate tool for simulating AHI thermal infrared brightness temperatures.
• The model's speed and accuracy make it suitable for operational applications in satellite meteorology.
• ERTM provides a reliable method for analyzing atmospheric conditions using satellite-derived infrared data.