First Retrievals of Surface and Atmospheric Properties Using EnMAP Measurements over Antarctica

Abstract

The paper presents the first retrievals of clean snow properties using spaceborne hyperspectral observations via the Environmental Mapping and Analysis Program (EnMAP). The location close to the Concordia station at the Dome C Plateau (Antarctica) was selected. At this location, the atmospheric effects (except molecular light scattering and absorption) are weak, and the simplified atmospheric correction scheme could be applied. The ice grain size, snow specific surface area, and snow spectral and broadband albedos were retrieved using single-view EnMAP measurements. In addition, we propose a technique to retrieve trace gas concentrations (e.g., water vapor and ozone) from EnMAP observations over the snow surfaces. A close correspondence of satellite and ground-measured parameters was found.

SNOWTRAN: A Fast Radiative Transfer Model for Polar Hyperspectral Remote Sensing Applications

“…Indeed, we have derived the value of d e f ,0 = d e f ,1 = 0.53 mm from the algorithm described in [27] for the area A (see above), which is close to the value of d e f ,1030nm derived in the framework of the algorithm discussed in this paper. It should be pointed out that the presented algorithm and the one described in [27] are based on a different system of equations. Therefore, our conclusions confirm the consistency of both algorithms, even though the current algorithm is able to determine the grain sizes at the very top of the snow surface, which is not the case for the algorithm described in [27].…”

“…Because the value of K 1 is close to one, one may expect that the snow observed using the couple of wavelengths of 1030 and 1235 nm can be considered as a homogeneous one. Therefore, the algorithm proposed in [27] is valid for the case considered here. Indeed, we have derived the value of d e f ,0 = d e f ,1 = 0.53 mm from the algorithm described in [27] for the area A (see above), which is close to the value of d e f ,1030nm derived in the framework of the algorithm discussed in this paper.…”

“…Therefore, the algorithm proposed in [27] is valid for the case considered here. Indeed, we have derived the value of d e f ,0 = d e f ,1 = 0.53 mm from the algorithm described in [27] for the area A (see above), which is close to the value of d e f ,1030nm derived in the framework of the algorithm discussed in this paper. It should be pointed out that the presented algorithm and the one described in [27] are based on a different system of equations.…”

“…The EnMAP measurements have been performed on 15 February 2023 at 00:36 UTC. We have used the values of a surface pressure of 651 hPa, surface height of 3233 m, and average values of pressure and temperature along vertical equal to 491 hPA and 229 K, as in our previous publication [27]. The values of TOC (250DU) and PWV (0.175 cm) were taken coincidentally with those measured at the closely located Concordia research station (Dome C, 75S, 123.3 • E).…”

“…It should be pointed out that the presented algorithm and the one described in [27] are based on a different system of equations. Therefore, our conclusions confirm the consistency of both algorithms, even though the current algorithm is able to determine the grain sizes at the very top of the snow surface, which is not the case for the algorithm described in [27]. Although we do not have grain sizes measured in situ and collocated with satellite measurements, our results are consistent with those presented in [30], where the most frequent grain size diameters are in the range of 0.2-0.4 mm at another coastal Antarctic site (67.7S, 139.72E, Adelie Land).…”