A decade-plus of Antarctic sea ice thickness and volume estimates from CryoSat-2 using a physical model and waveform fitting

IF 4.4 2区地球科学 Q1 GEOGRAPHY, PHYSICAL

Cryosphere Pub Date : 2023-06-23 DOI:10.5194/tc-17-2487-2023

S. Fons, N. Kurtz, M. Bagnardi

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引用次数: 1

Abstract

Abstract. We estimate the snow depth and snow freeboard of Antarctic sea ice using a comprehensive retrieval method (referred to as CryoSat-2 Waveform Fitting for Antarctic sea ice, or CS2WFA) consisting of a physical waveform model and a waveform-fitting process that fits modeled waveforms to CryoSat-2 data. These snow depth and snow freeboard estimates are combined with snow, sea ice, and sea water density values to calculate the sea ice thickness and volume over an 11+ year span between 2010 and 2021. We first compare our snow freeboard, snow depth, and sea ice thickness estimates to other altimetry- and ship-based observations and find good agreement overall in both along-track and monthly gridded comparisons. Some discrepancies exist in certain regions and seasons that are theorized to come from both sampling biases and the differing assumptions in the retrieval methods. We then present an 11+ year time series of sea ice thickness and volume both regionally and pan-Antarctic. This time series is used to uncover intra-decadal changes in the ice cover between 2010 and 2021, showing small, competing regional thickness changes of less than 0.5 cm yr−1 in magnitude. Finally, we place these thickness estimates in the context of a longer-term, snow freeboard-derived, laser–radar sea ice thickness time series that began with NASA's Ice, Cloud, and land Elevation Satellite (ICESat) and continues with ICESat-2 and contend that reconciling and validating this longer-term, multi-sensor time series will be important in better understanding changes in the Antarctic sea ice cover.

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使用物理模型和波形拟合的CryoSat-2对南极海冰厚度和体积的十多年估计

摘要我们使用综合检索方法（称为CryoSat-2南极海冰波形拟合，或CS2WFA）来估计南极海冰的雪深和雪干舷，该方法包括物理波形模型和将建模波形拟合到CryoSat2数据的波形拟合过程。这些雪深和雪干舷估计值与雪、海冰和海水密度值相结合，以计算2010年至2021年间11年以上的海冰厚度和体积。我们首先将我们的雪干舷、雪深度和海冰厚度估计值与其他测高和基于船舶的观测值进行比较，并在沿轨道和每月网格比较中发现总体一致性良好。某些地区和季节存在一些差异，理论上这些差异来自采样偏差和检索方法中的不同假设。然后，我们呈现了区域和泛南极海冰厚度和体积的11年以上时间序列。该时间序列用于揭示2010年至2021年间冰盖的十年内变化，显示出小于0.5的小的、相互竞争的区域厚度变化厘米 yr−1级。最后，我们将这些厚度估计放在一个长期的、基于雪干舷的激光雷达海冰厚度时间序列的背景下，该时间序列始于美国国家航空航天局的冰、云和陆地高程卫星（ICESat），并延续到ICESat-2，多传感器时间序列对于更好地了解南极海冰覆盖的变化将是重要的。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Cryosphere GEOGRAPHY, PHYSICAL-GEOSCIENCES, MULTIDISCIPLINARY

CiteScore

8.70

自引率

17.30%

发文量

240

审稿时长

4-8 weeks

期刊介绍： The Cryosphere (TC) is a not-for-profit international scientific journal dedicated to the publication and discussion of research articles, short communications, and review papers on all aspects of frozen water and ground on Earth and on other planetary bodies. The main subject areas are the following: ice sheets and glaciers; planetary ice bodies; permafrost and seasonally frozen ground; seasonal snow cover; sea ice; river and lake ice; remote sensing, numerical modelling, in situ and laboratory studies of the above and including studies of the interaction of the cryosphere with the rest of the climate system.