Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process
The irregular interannual variations observed in the Greenland ice sheet (GrIS) mass balance can be interpreted as stochastic. These variations often have large amplitudes, and, if not accounted for correctly in the mass change model parameterization, could have profound impacts on the estimate of t...
Published in: | Earth and Planetary Science Letters |
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2020
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Online Access: | https://orbit.dtu.dk/en/publications/6bc1b156-ce80-4e36-a29d-255632f14695 https://doi.org/10.1016/j.epsl.2020.116518 https://backend.orbit.dtu.dk/ws/files/218539550/1_s2.0_S0012821X20304623_main.pdf |
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ftdtupubl:oai:pure.atira.dk:publications/6bc1b156-ce80-4e36-a29d-255632f14695 2024-05-12T08:04:28+00:00 Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process Zhang, Bao Liu, Lin Yao, Yibin van Dam, Tonie Khan, Shfaqat Abbas 2020 application/pdf https://orbit.dtu.dk/en/publications/6bc1b156-ce80-4e36-a29d-255632f14695 https://doi.org/10.1016/j.epsl.2020.116518 https://backend.orbit.dtu.dk/ws/files/218539550/1_s2.0_S0012821X20304623_main.pdf eng eng https://orbit.dtu.dk/en/publications/6bc1b156-ce80-4e36-a29d-255632f14695 info:eu-repo/semantics/openAccess Zhang , B , Liu , L , Yao , Y , van Dam , T & Khan , S A 2020 , ' Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process ' , Earth and Planetary Science Letters , vol. 549 , 116518 . https://doi.org/10.1016/j.epsl.2020.116518 Greenland Secular mass changes Interannual variations Stochastic process article 2020 ftdtupubl https://doi.org/10.1016/j.epsl.2020.116518 2024-04-17T15:12:44Z The irregular interannual variations observed in the Greenland ice sheet (GrIS) mass balance can be interpreted as stochastic. These variations often have large amplitudes, and, if not accounted for correctly in the mass change model parameterization, could have profound impacts on the estimate of the secular trend and acceleration. Here we propose a new mass trajectory model that includes both the conventional deterministic components and a stochastic component. This new model simultaneously estimates the secular rate and acceleration, seasonal components, and the stochastic component of mass changes. Simulations show that this new model improves estimates of model parameters, especially accelerations, over the conventional model without stochastic component. Using this new model, we estimate an acceleration of −1.6 ± 1.3 Gt/yr 2 in mass change (minus means mass loss) for 2003-2017 using the Gravity Recovery and Climate Experiment (GRACE) data and an acceleration of −1.1 ± 1.3 Gt/yr 2 using the modeled surface mass balance plus observed ice discharge. The corresponding rates are estimated to be −288.2 ± 12.7 Gt/yr and −274.9 ± 13.0 Gt/yr. The greatest discrepancies between the new and the conventional model parameter determinations are found in the acceleration estimates, −1.6 Gt/yr2 vs. −7.5 Gt/yr 2 from the GRACE data. The estimated accelerations using the new method are apparently smaller than those estimated by other studies in terms of mass loss. Our quantitative analysis elucidates that the acceleration estimate using the conventional method is the lower bound (i.e., −7.5 Gt/yr 2 for 2003–2017) while the acceleration estimated by the new method lies in the middle of the possible ranges. It is also found that these discrepancies between the new and the conventional methods diminish with sufficiently long (>20 yr) observation records. Article in Journal/Newspaper Greenland Ice Sheet Technical University of Denmark: DTU Orbit Greenland Earth and Planetary Science Letters 549 116518 |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
topic |
Greenland Secular mass changes Interannual variations Stochastic process |
spellingShingle |
Greenland Secular mass changes Interannual variations Stochastic process Zhang, Bao Liu, Lin Yao, Yibin van Dam, Tonie Khan, Shfaqat Abbas Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process |
topic_facet |
Greenland Secular mass changes Interannual variations Stochastic process |
description |
The irregular interannual variations observed in the Greenland ice sheet (GrIS) mass balance can be interpreted as stochastic. These variations often have large amplitudes, and, if not accounted for correctly in the mass change model parameterization, could have profound impacts on the estimate of the secular trend and acceleration. Here we propose a new mass trajectory model that includes both the conventional deterministic components and a stochastic component. This new model simultaneously estimates the secular rate and acceleration, seasonal components, and the stochastic component of mass changes. Simulations show that this new model improves estimates of model parameters, especially accelerations, over the conventional model without stochastic component. Using this new model, we estimate an acceleration of −1.6 ± 1.3 Gt/yr 2 in mass change (minus means mass loss) for 2003-2017 using the Gravity Recovery and Climate Experiment (GRACE) data and an acceleration of −1.1 ± 1.3 Gt/yr 2 using the modeled surface mass balance plus observed ice discharge. The corresponding rates are estimated to be −288.2 ± 12.7 Gt/yr and −274.9 ± 13.0 Gt/yr. The greatest discrepancies between the new and the conventional model parameter determinations are found in the acceleration estimates, −1.6 Gt/yr2 vs. −7.5 Gt/yr 2 from the GRACE data. The estimated accelerations using the new method are apparently smaller than those estimated by other studies in terms of mass loss. Our quantitative analysis elucidates that the acceleration estimate using the conventional method is the lower bound (i.e., −7.5 Gt/yr 2 for 2003–2017) while the acceleration estimated by the new method lies in the middle of the possible ranges. It is also found that these discrepancies between the new and the conventional methods diminish with sufficiently long (>20 yr) observation records. |
format |
Article in Journal/Newspaper |
author |
Zhang, Bao Liu, Lin Yao, Yibin van Dam, Tonie Khan, Shfaqat Abbas |
author_facet |
Zhang, Bao Liu, Lin Yao, Yibin van Dam, Tonie Khan, Shfaqat Abbas |
author_sort |
Zhang, Bao |
title |
Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process |
title_short |
Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process |
title_full |
Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process |
title_fullStr |
Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process |
title_full_unstemmed |
Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process |
title_sort |
improving the estimate of the secular variation of greenland ice mass in the recent decades by incorporating a stochastic process |
publishDate |
2020 |
url |
https://orbit.dtu.dk/en/publications/6bc1b156-ce80-4e36-a29d-255632f14695 https://doi.org/10.1016/j.epsl.2020.116518 https://backend.orbit.dtu.dk/ws/files/218539550/1_s2.0_S0012821X20304623_main.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
Zhang , B , Liu , L , Yao , Y , van Dam , T & Khan , S A 2020 , ' Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process ' , Earth and Planetary Science Letters , vol. 549 , 116518 . https://doi.org/10.1016/j.epsl.2020.116518 |
op_relation |
https://orbit.dtu.dk/en/publications/6bc1b156-ce80-4e36-a29d-255632f14695 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2020.116518 |
container_title |
Earth and Planetary Science Letters |
container_volume |
549 |
container_start_page |
116518 |
_version_ |
1798846686266654720 |