Articles | Volume 7, issue 12
Atmos. Meas. Tech., 7, 4117–4122, 2014
https://doi.org/10.5194/amt-7-4117-2014
Atmos. Meas. Tech., 7, 4117–4122, 2014
https://doi.org/10.5194/amt-7-4117-2014

Research article 03 Dec 2014

Research article | 03 Dec 2014

Characterization of model errors in the calculation of tangent heights for atmospheric infrared limb measurements

M. Ridolfi1,2 and L. Sgheri3 M. Ridolfi and L. Sgheri
  • 1Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy
  • 2Istituto di Fisica Applicata "Carrara", Consiglio Nazionale delle Ricerche, Florence, Italy
  • 3Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche, Florence, Italy

Abstract. We review the main factors driving the calculation of the tangent height of spaceborne limb measurements: the ray-tracing method, the refractive index model and the assumed atmosphere. We find that commonly used ray tracing and refraction models are very accurate, at least in the mid-infrared. The factor with largest effect in the tangent height calculation is the assumed atmosphere. Using a climatological model in place of the real atmosphere may cause tangent height errors up to ± 200 m. Depending on the adopted retrieval scheme, these errors may have a significant impact on the derived profiles.

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Short summary
In this paper, we review the main factors driving the calculation of the tangent height of spaceborne limb measurements: the ray-tracing method, the refractive index model and the assumed atmosphere. We find that commonly used ray-tracing and refraction models are very accurate, at least in the mid-infrared. The factor with the largest effect in the tangent height calculation is the assumed atmosphere, which may cause errors of up to 200m.