Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 4.713
IF4.713
IF 5-year value: 4.927
IF 5-year
4.927
CiteScore value: 8.0
CiteScore
8.0
SNIP value: 1.425
SNIP1.425
IPP value: 4.65
IPP4.65
SJR value: 2.353
SJR2.353
Scimago H <br class='widget-line-break'>index value: 71
Scimago H
index
71
h5-index value: 53
h5-index53
Preprints
https://doi.org/10.5194/tc-2020-236
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-2020-236
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  26 Aug 2020

26 Aug 2020

Review status
This preprint is currently under review for the journal TC.

Three-in-one: GPS-IR measurements of ground surface elevation changes, soil moisture, and snow depth at a permafrost site in the northeastern Qinghai-Tibet Plateau

Jiahua Zhang1, Lin Liu1, Lei Su2,3, and Tao Che2,4 Jiahua Zhang et al.
  • 1Earth System Science Programme, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, 999077, China
  • 2Heihe Remote Sensing Experimental Research Station, Key Laboratory of Remote Sensing of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
  • 3University of Chinese Academy of Sciences, Beijing, 100049, China
  • 4Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100101, China

Abstract. Ground surface elevation changes, soil moisture, and snow depth are all essential variables for studying the dynamics of the active layer and permafrost. GPS interferometric reflectometry (GPS-IR) has been used to measure surface elevation changes and snow depth in permafrost areas. However, its applicability to estimating soil moisture in permafrost regions has not been assessed. Moreover, these variables were usually measured separately at different sites. Integrating their estimates at one site facilitates the comprehensive utilization of GPS-IR in permafrost studies. In this study, we run simulations to elucidate that the commonly-used GPS-IR method for estimating soil moisture content cannot be directly used in permafrost areas, because it does not consider the bias introduced by the seasonal surface elevation changes due to thawing of the active layer. We propose a solution to improve this default method by introducing modeled surface elevation changes. We validate this modified method using the GPS data and in situ observations at a permafrost site in the northeastern Qinghai-Tibet Plateau (QTP). The root-mean-square error and correlation coefficient between the GPS-IR estimates of soil moisture content and the in situ ones improve from 1.85 % to 1.51 % and 0.71 to 0.82, respectively. We also implement a framework to integrate the GPS-IR estimates of these three variables at one site and illustrate it using the same site in the QTP as an example. This study highlights the improvement to the default method, which makes the GPS-IR valid in estimating soil moisture content in permafrost areas. The three-in-one framework is able to fully utilize the GPS-IR in permafrost areas and can be extended to other sites such as those in the Arctic. This study is also the first to use GPS-IR to estimate environmental variables in the QTP, which fills a spatial gap and provides complementary measurements to those of ground temperature and active layer thickness.

Jiahua Zhang et al.

Interactive discussion

Status: open (until 10 Dec 2020)
Status: open (until 10 Dec 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Jiahua Zhang et al.

Jiahua Zhang et al.

Viewed

Total article views: 216 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
163 51 2 216 19 1 2
  • HTML: 163
  • PDF: 51
  • XML: 2
  • Total: 216
  • Supplement: 19
  • BibTeX: 1
  • EndNote: 2
Views and downloads (calculated since 26 Aug 2020)
Cumulative views and downloads (calculated since 26 Aug 2020)

Viewed (geographical distribution)

Total article views: 219 (including HTML, PDF, and XML) Thereof 216 with geography defined and 3 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 26 Nov 2020
Publications Copernicus
Download
Short summary
We improve the commonly-used GPS-IR method for estimating soil moisture in permafrost areas, which does not consider the bias introduced by seasonal surface elevation changes. We implement a framework to integrate the GPS-IR measurements of ground surface elevation changes, soil moisture, and snow depth at one GPS site, and illustrate an example by using a GPS site in Qinghai-Tibet Plateau. This study is also the first to use GPS-IR to measure environmental variables in Qinghai-Tibet Plateau.
We improve the commonly-used GPS-IR method for estimating soil moisture in permafrost areas,...
Citation