Work

Construction of a Global Atmospheric Refractivity Model for Optical Wavelengths Based on Temporal Evolution Characteristics

Year: 2026

Type: article

Abstract: Atmospheric refractivity model accuracy is important for refraction correction, starlight refraction navigation, and related optoelectronic applications. To address the insufficient understanding of refractivity temporal evolution and the lack of clear criteria for selecting model temporal resolution, this study constructs a global four‐dimensional gridded atmospheric refractivity data set from ERA5 reanalysis data for 2015–2024, with a spatial resolution of 0.25° × 0.25° and an hourly temporal resolution. Using this data set, we analyze the global latitudinal and longitudinal distributions, seasonal variability, and temporal evolution of refractivity at hourly, daily, and interannual scales. We further evaluate the effects of temporal span and statistical period on refractivity stability. Considering both model accuracy and data complexity, we construct the model using the 2015–2024 data set after applying monthly ±2σ outlier screening to the hourly refractivity samples at each grid point and height level, and adopt a 5‐day × 12‐hr temporal resolution for the global atmospheric refractivity model. Radiosonde observations from eight high‐latitude stations in both hemispheres are used to compare the proposed model with four commonly used atmospheric models. At the selected high‐latitude validation stations, the proposed model achieves lower RMSE values than the existing representative atmospheric models in several altitude ranges, particularly below 15 km and during Northern Hemisphere winter, while maintaining comparable performance at 20 and 25 km. The proposed temporal‐resolution selection scheme provides a useful reference for optimizing high‐precision global atmospheric refractivity models.

Source: Earth and Space Science

DOI: 10.1029/2026ea005286

Authors: Zhiyan Ding, Pengfei Wu, Wenyue Zhu

Institutions: University of Science and Technology of China, Hefei Institutes of Physical Science, Anhui Institute of Optics and Fine Mechanics

Language: English

Topic: Radio Wave Propagation Studies

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,650

Funders: European Centre for Medium-Range Weather Forecasts, National Oceanic and Atmospheric Administration