Understanding SMOS data in Antarctica

Macelloni, Giovanni; Brogioni, Marco; Aksoy, Mustafa; Johnson, Joel T.; Jezek, Kenneth C.; Drinkwater, Mark R.

doi:10.1109/igarss.2014.6947263

Cited by 10 publications

(3 citation statements)

References 6 publications

(5 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…showing a variation b1 K over a 50-km scale) it changes smoothly by several kelvins on a larger spatial scale (i.e. 500 km) (Macelloni et al, 2014). Spatial analyses have also revealed some well-known glaciological features in the T B over the East Antarctica Plateau, such as the presence of Lake Vostok .…”

Section: Introductionmentioning

confidence: 96%

Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau

Macelloni

Leduc-Leballeur

Brogioni

et al. 2016

Remote Sensing of Environment

Self Cite

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 96%

Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau

Macelloni

Leduc-Leballeur

Brogioni

et al. 2016

Remote Sensing of Environment

Self Cite

View full text Add to dashboard Cite

“…No significant correlation has been found with the bedrock (R ∼ 0–0.2). Recent studies pointed out the relationship between the bedrock and the measured SMOS T B at the Dome‐C region [ Macelloni et al ., ; Skou et al ., ]. Hence, we looked at correlations over Dome‐C and obtained values of R i ∼ 0.4–0.6 for IceTL and R b ∼ 0.3–0.4 for bedrock.…”

Section: Resultsmentioning

confidence: 99%

Ice thickness effects on Aquarius brightness temperatures over Antarctica

et al. 2015

View full text Add to dashboard Cite

The Dome-C region, in the East Antarctic Plateau, is regarded as an ideal natural laboratory for calibration/validation of space-borne microwave radiometers. At L-band, the thermal stability of this region has been confirmed by several experimental campaigns. However, its use as an independent external calibration target has recently been questioned due to some spatial inhomogeneities and seasonal effects revealed in the brightness temperatures (T B ) acquired in this area. This paper shows the observed relationship, from exploratory research, between the Antarctic ice thickness spatial variations and the measured Aquarius T B changes. A 3-months no-daylight period during the Austral winter has been analyzed. Four transects have been defined over East Antarctica covering areas with different ice thickness variations and ranges. The theoretical L-band penetration depth has been estimated to understand the possible contributions to the measured signal. A good agreement has been observed between Aquarius T B and ice thickness variations over the whole Antarctica, with correlations of 0.6-0.7. The two variables show a linear trend with slopes of 8.3-9.5 K/km. No correlation has been observed with the subglacial bedrock. The maximum L-band penetration depth has been estimated to be 1-1.5 km. Results are therefore consistent: the spatial variations found on Aquarius T B are not related to the emissivity of the bedrock, which lies deeper. This study provides evidence that new L-band satellite observations could contribute to further our understanding of Antarctic geophysical processes.

show abstract

“…However, it highlights significant spatial variations [10] (Figure 1a). Brightness temperature appears highly correlated with surface temperature (Figure 1b), and a second-order influence of ice thickness has also been revealed [23,24], explained by the vertical profile of temperature. A large part of Antarctic basal ice is at melting point [25], so that the mean vertical temperature gradient is firstly governed by surface temperature and ice thickness, and secondly modulated by vertical and horizontal ice velocities through advection.…”

Section: Introductionmentioning

confidence: 82%

Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations

et al. 2018

Self Cite

View full text Add to dashboard Cite

Microwave emissions at the L-band (1–2 GHz) in Antarctica are characterized by a significant contribution of ice layers at great depth, from hundreds to a thousand meters. Brightness temperatures, thus, could provide the internal temperature of the ice sheet. However, there are two difficulties to overcome in developing an accurate retrieval algorithm. First, it is difficult to know precisely from which depths waves are emanating because the ice-absorption coefficient is uncertain at the L-band, despite several formulations proposed in the literature over the past few decades. Second, emissivity potentially varies in Antarctica due to remnant scattering in firn (or ice), even at the Brewster angle, and despite the low frequency, limiting the accuracy of the estimate of the physical temperature. Here, we present a retrieval method able to disentangle the absorption and emissivity effects from brightness temperature over the whole continent. We exploit the fact that scattering and absorption are controlled by different physical parameters and phenomena that can be considered as statistically independent. This independence provides a constraint to the retrieval method, that is then well-conditioned and solvable. Our results show that (1) the retrieved absorption agrees with the permittivity model proposed by Mätzler et al. (2006), and (2) emissivity shows significant variations, up to 6% over the continent, which are correlated with wind speed and accumulation patterns. A possible cause of this latter point is density heterogeneity and sastrugi buried in the firn. These two results are an important step forward for the accurate retrieval of internal temperature using low-frequency microwave radiometers.

show abstract

Understanding SMOS data in Antarctica

Cited by 10 publications

References 6 publications

Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau

Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau

Ice thickness effects on Aquarius brightness temperatures over Antarctica

Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations

Contact Info

Product

Resources

About