Schmidtke et al. (2026) A novel method and instrument design for more accurate estimation of annual changes in spectral outgoing radiation of the Earth from 200 to 1100 nm

Identification

• Journal: Open MIND
• Year: 2026
• Date: 2026-01-01
• Authors: Gerhard Schmidtke, Raimund Brunner, Christoph Jacobi, :unav
• DOI: 10.24406/publica-7622

Research Groups

• Fraunhofer-Institut für Physikalische Messtechnik IPM
• Universität Leipzig, Institut für Meteorologie

Short Summary

This paper proposes a novel method and instrument design, SORACES, for more accurate and time-stable estimation of annual changes in the Earth's spectral outgoing radiation (200 to 1100 nm). It introduces a quasi-calibration process and a spectrometer system capable of measuring both spectral solar irradiance and spectral outgoing radiation with high precision and a wide dynamic range, aiming to improve climate research data.

Objective

• To design a novel method and instrument (SORACES) for more accurate and time-stable estimation of annual changes in the Earth's spectral outgoing radiation (SOR) from 200 nm to 1100 nm, thereby contributing to climate research and enabling the derivation of annual changes in global green biomass.

Study Configuration

• Spatial Scale: Global (implied by "global cover of the Earth’s green biomass" and "Earth's energy imbalance").
• Temporal Scale: Annual changes, across a solar cycle, time-stable measurements.

Methodology and Data

• Models used: Not applicable; the paper describes an instrument design and a "quasi-calibration" process, not a computational model.
• Data sources: The proposed SORACES instrument, equipped with 16 compact Rowland spectrometers, 80 photomultiplier tubes (PMTs), and 32 radiation attenuators, is designed to generate spectral solar irradiance (SSI) and spectral outgoing radiation of the Earth (SOR) data.

Main Results

• The paper presents the design of SORACES, a novel spectrometer system capable of measuring spectral solar irradiance (SSI) and spectral outgoing radiation of the Earth (SOR) simultaneously with high statistical significance across a spectral range of 200 nm to 1100 nm.
• The system incorporates 32 radiation attenuators, enabling a dynamic range of up to 12 orders of magnitude to cover the significant difference between SSI and SOR.
• A "quasi-calibration" process is introduced to compensate for instrument aging and ensure time-stable measurements over a solar cycle.
• The proposed instrument is designed to provide time-stable estimated SOR data for climate research, facilitating the derivation of annual changes in the global cover of the Earth’s green biomass.

Contributions

• Introduction of a novel instrument design (SORACES) specifically tailored for highly accurate and time-stable estimation of spectral outgoing radiation of the Earth (SOR) and spectral solar irradiance (SSI) across a broad spectral range (200 nm to 1100 nm).
• Development of a "quasi-calibration" method to address instrument aging, ensuring long-term data stability crucial for climate research.
• The proposed system offers an unprecedented dynamic range (12 orders of magnitude) for simultaneous measurement of vastly different radiation levels (SSI and SOR) using the same detectors.
• Aims to provide more accurate and traceable data for Earth's energy imbalance (EEI) estimation, which is currently limited by the lack of precise radiation standards.

Funding

• Not explicitly mentioned in the provided text.

Citation

@article{Schmidtke2026novel,
  author = {Schmidtke, Gerhard and Brunner, Raimund and Jacobi, Christoph and :unav},
  title = {A novel method and instrument design for more accurate estimation of annual changes in spectral outgoing radiation of the Earth from 200 to 1100 nm},
  journal = {Open MIND},
  year = {2026},
  doi = {10.24406/publica-7622},
  url = {https://doi.org/10.24406/publica-7622}
}