https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33383 Wed 28 Feb 2024 14:57:39 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44988 Wed 26 Oct 2022 09:28:30 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33382 Wed 15 Mar 2023 10:18:11 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:49851 Wed 13 Mar 2024 14:13:21 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27686 Wed 11 Apr 2018 14:39:58 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44637 1 cycle-per-revolution (CPR), >7 CPR, and 7-40 CPR, respectively. Considering the actual error of residual KBR data, it is feasible to accurately compute the gravimetric observables directly from band-pass filtered residual range-rate and range-acceleration data, and employ them for analyses concerning the regional time-variable gravity field of the Earth such as continental hydrology.]]> Tue 18 Oct 2022 14:55:33 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35328 5 cycles‐per‐revolution. The admittance spectrum quantifies that the LGD response to range‐acceleration is systematically larger at lower frequencies, due to the increased contribution of centrifugal acceleration. We find that the correlation and admittance spectra are stationary (i.e., are independent of time, satellite altitude, and gravity strength) and, therefore, can be determined a priori with high fidelity. We determine the spectral transfer function and the equivalent time domain filter. Using both synthetic and actual GRACE data, we demonstrate that in situ LGD can be estimated via the transfer function with an estimation error of 0.15 nm/s², whereas the actual GRACE data error is around 1.0 nm/s². We present an application of LGD data to surface water storage changes in large basins such as Amazon, Congo, Parana, and Mississippi by processing 11 years of GRACE data. Runoff routing models are calibrated directly using LGD data. Our technique demonstrates a new way of using GRACE data by forward modeling of various geophysical models and in‐orbit comparison with such GRACE in situ data.]]> Tue 16 Jul 2019 12:19:45 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:41987 Tue 16 Aug 2022 15:55:29 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:41972 Tue 16 Aug 2022 15:27:28 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:41971 Tue 16 Aug 2022 15:13:22 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46606 2. In this paper, a forward model is developed to determine the increased water surface level corresponding to GRACE observations, estimated to be about 120 m. In contrast to GRACE, the TWS derived from land surface models cannot capture the increased ΔTWS, due to the lack of reservoir routing algorithms in the models. In addition, the land subsidence was calculated using the disk load model constructed based on the GRACE-derived lake level and Landsat-derived lake extent; the result is validated with the GPS data from BIN1 station, located at the western coast of Borneo. The commencement stage of the Bakun Dam induces the large-scale land subsidence, which causes the GPS-BIN1 station to subside by ~9 mm, and move toward the Bakun Lake by ~4 mm. Computation of the surface displacements directly from GRACE spherical harmonic coefficient data fails to capture the subsidence feature, mainly due to the truncation error. Overall, this study demonstrates that evaluating GRACE in conjunction with Landsat, LSMs, and GPS data allows the exploitation of the gravity signal at a much smaller spatial scale than its intrinsic resolution. Benefiting from global coverage, the newly developed satellite-based algorithm is a valuable tool for assessing the impacts of reservoir operation on hydrological and geophysical changes from local to regional scales.]]> Tue 14 May 2024 10:25:42 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34730 10 mm, followed by gradual uplift of 10 mm over the next 3–4 years, as water storage depletes slowly through evapotranspiration. The geodetic measurements find significant imbalance in the water cycle budget in Australia over 2010–2015. Plain Language Summary: This study finds how the Australian continent has deformed responding to atmospheric and water cycle changes sustained over periods of long‐term droughts and the heavy precipitation during the La Niña. The majority of the Australian continent was depressed by the La Niña water load in 2010–2011 and slowly rebounded afterward as the water evaporates from the continent. The geodetic measurements (like GPS and Gravity Recovery and Climate Experiment) find significant imbalance in the water cycle budget in Australia over 2010–2015.]]> Tue 03 Sep 2019 18:30:41 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34927 Tue 03 Sep 2019 17:58:44 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:39939 in-situ groundwater level data in the NCP. Compared to the model computation, there was a significant improvement in terms of cross correlation, on average, from 0.12 (before assimilation) to 0.54 (after assimilation). This study demonstrates the effectiveness of GRACE data assimilation toward reliable estimation of ground water storage variation in the NCP, and its promise to quantify the potential implication of water supply from the South-to-North Water Transfer Project within the NCP.]]> Thu 30 Jun 2022 13:40:45 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40976 Thu 21 Jul 2022 08:52:16 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40003 Thu 14 Jul 2022 13:18:17 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37420 Thu 12 Nov 2020 17:52:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:26688 Thu 09 Aug 2018 11:37:07 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36727 Thu 02 Jul 2020 09:24:42 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:42699 Thu 01 Sep 2022 09:41:19 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:31294 priori model of present-day glacial isostatic adjustment (GIA) in North America via least-squares adjustment. The result is an updated GIA model wherein the final predicted signal is informed by both observational data, and prior knowledge (or intuition) of GIA inferred from models. The data-driven method allows calculation of the uncertainties of predicted GIA fields, and thus offers a significant advantage over predictions from purely forward GIA models. In order to assess the influence each dataset has on the final GIA prediction, the vertical land motion and GRACE-measured gravity data are incorporated into the model first independently (i.e., one dataset only), then simultaneously. The relative weighting of the datasets and the prior input is iteratively determined by variance component estimation in order to achieve the most statistically appropriate fit to the data. The best-fit model is obtained when both datasets are inverted and gives respective RMS misfits to the GPS and GRACE data of 1.3 mm/yr and 0.8 mm/yr equivalent water layer change. Non-GIA signals (e.g., hydrology) are removed from the datasets prior to inversion. The post-fit residuals between the model predictions and the vertical motion and gravity datasets, however, suggest particular regions where significant non-GIA signals may still be present in the data, including unmodeled hydrological changes in the central Prairies west of Lake Winnipeg. Outside of these regions of misfit, the posterior uncertainty of the predicted model provides a measure of the formal uncertainty associated with the GIA process; results indicate that this quantity is sensitive to the uncertainty and spatial distribution of the input data as well as that of the prior model information. In the study area, the predicted uncertainty of the present-day GIA signal ranges from ~0.2-1.2 mm/yr for rates of vertical land motion, and from ~3-4 mm/yr of equivalent water layer change for gravity variations.]]> Sat 24 Mar 2018 08:44:13 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35538 Mon 26 Aug 2019 13:08:06 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32388 Mon 23 Sep 2019 13:21:58 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32889 Mon 23 Sep 2019 12:24:56 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32353 Mon 23 Sep 2019 11:08:42 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44595 Mon 17 Oct 2022 15:14:33 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36603 Mon 15 Jun 2020 11:45:44 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35025 Fri 31 May 2019 16:24:59 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36497 Fri 22 May 2020 15:40:04 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40034 2 at 490 km altitude, improved by 1 order of magnitude from KBR. This allows LRI to uniquely detect un-/mis-modeled short-wavelength gravitational perturbations. We employed all LRI data in 2019 to validate various state-of-the-art global static gravity field models and show that LRI measurements, even over 1 month, can distinguish subtle differences among the models computed from ~15 years of GRACE KBR and ~4 years of Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) gradiometry data. Ultra-precise LRI measurements will be yet another critical data set for future gravity field model development.]]> Fri 15 Jul 2022 10:11:22 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40035 2. There is good agreement between GRACE measurements and tsunami models for the three events. Complementarily to buoys, ocean bottom pressure sounders, and satellite altimeters, GRACE is sensitive to the long-wavelength spatial scale of tsunamis and provides an independent source of information for assessing alternate early earthquake and tsunami models. Our study demonstrates an innovative way of applying GRACE and GRACE Follow-On data to detect transient geophysical mass changes which cannot be observed by the conventional monthly Level-2 and mascon solutions.]]> Fri 15 Jul 2022 10:11:21 AEST ]]>