Articles | Volume 36, issue 3
https://doi.org/10.5194/angeo-36-761-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/angeo-36-761-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Comparison of accelerometer data calibration methods used in thermospheric neutral density estimation
Kristin Vielberg
CORRESPONDING AUTHOR
Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany
Ehsan Forootan
Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany
School of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, UK
Christina Lück
Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany
Anno Löcher
Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany
Jürgen Kusche
Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany
Klaus Börger
German Space Situational Awareness Centre (GSSAC), Mühlenstrasse 89, 47589 Uedem, Germany
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Matthias O. Willen, Martin Horwath, Eric Buchta, Mirko Scheinert, Veit Helm, Bernd Uebbing, and Jürgen Kusche
The Cryosphere, 18, 775–790, https://doi.org/10.5194/tc-18-775-2024, https://doi.org/10.5194/tc-18-775-2024, 2024
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Shrinkage of the Antarctic ice sheet (AIS) leads to sea level rise. Satellite gravimetry measures AIS mass changes. We apply a new method that overcomes two limitations: low spatial resolution and large uncertainties due to the Earth's interior mass changes. To do so, we additionally include data from satellite altimetry and climate and firn modelling, which are evaluated in a globally consistent way with thoroughly characterized errors. The results are in better agreement with independent data.
Petra Döll, H. M. Mehedi Hasan, Kerstin Schulze, Helena Gerdener, Lara Börger, Somayeh Shadkam, Sebastian Ackermann, Seyed-Mohammad Hosseini-Moghari, Hannes Müller Schmied, Andreas Güntner, and Jürgen Kusche
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2023-18, https://doi.org/10.5194/hess-2023-18, 2023
Revised manuscript accepted for HESS
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For the pilot region Mississippi River basin, we explored three model calibration approaches for using both streamflow and total water storage anomaly (TWSA) observations to adjust parameter sets of a global hydrological model. We developed a method for considering the observation uncertainties to determine not only optimal but also behavioral parameter sets and model output uncertainty. Model performance was improved but trade-offs between optimal fits to streamflow and TWSA may be large.
Simon Deggim, Annette Eicker, Lennart Schawohl, Helena Gerdener, Kerstin Schulze, Olga Engels, Jürgen Kusche, Anita T. Saraswati, Tonie van Dam, Laura Ellenbeck, Denise Dettmering, Christian Schwatke, Stefan Mayr, Igor Klein, and Laurent Longuevergne
Earth Syst. Sci. Data, 13, 2227–2244, https://doi.org/10.5194/essd-13-2227-2021, https://doi.org/10.5194/essd-13-2227-2021, 2021
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GRACE provides us with global changes of terrestrial water storage. However, the data have a low spatial resolution, and localized storage changes in lakes/reservoirs or mass change due to earthquakes causes leakage effects. The correction product RECOG RL01 presented in this paper accounts for these effects. Its application allows for improving calibration/assimilation of GRACE into hydrological models and better drought detection in earthquake-affected areas.
L. Drees, J. Kusche, and R. Roscher
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., V-2-2020, 813–820, https://doi.org/10.5194/isprs-annals-V-2-2020-813-2020, https://doi.org/10.5194/isprs-annals-V-2-2020-813-2020, 2020
Isabel Meza, Stefan Siebert, Petra Döll, Jürgen Kusche, Claudia Herbert, Ehsan Eyshi Rezaei, Hamideh Nouri, Helena Gerdener, Eklavyya Popat, Janna Frischen, Gustavo Naumann, Jürgen V. Vogt, Yvonne Walz, Zita Sebesvari, and Michael Hagenlocher
Nat. Hazards Earth Syst. Sci., 20, 695–712, https://doi.org/10.5194/nhess-20-695-2020, https://doi.org/10.5194/nhess-20-695-2020, 2020
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The paper presents, for the first time, a global-scale drought risk assessment for both irrigated and rainfed agricultural systems while considering drought hazard indicators, exposure and expert-weighted vulnerability indicators. We identify global patterns of drought risk and, by disaggregating risk into its underlying components and factors, provide entry points for risk reduction.
Helena Gerdener, Olga Engels, and Jürgen Kusche
Hydrol. Earth Syst. Sci., 24, 227–248, https://doi.org/10.5194/hess-24-227-2020, https://doi.org/10.5194/hess-24-227-2020, 2020
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GRACE-derived drought indicators enable us to detect hydrological droughts based on changes observed in all storages. By performing synthetic experiments, we find that droughts identified by existing and modified indicators are biased by trends and GRACE-based spatial noise. A modified version of the Zhao et al. (2017) indicator is found to be particularly robust against spatial noise and is therefore applied to real GRACE data over South Africa.
Stefan Schröder, Anne Springer, Jürgen Kusche, Bernd Uebbing, Luciana Fenoglio-Marc, Bernd Diekkrüger, and Thomas Poméon
Hydrol. Earth Syst. Sci., 23, 4113–4128, https://doi.org/10.5194/hess-23-4113-2019, https://doi.org/10.5194/hess-23-4113-2019, 2019
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We propose deriving altimetric rating curves by
bridginggaps between time series from gauge and altimeter measurements using hydrological model simulations. We investigate several stations at the Niger River, which is a challenging region. We show that altimetry reproduces discharge well and enables continuing the gauge time series, albeit at a lower temporal resolution.
Christina Lück, Jürgen Kusche, Roelof Rietbroek, and Anno Löcher
Solid Earth, 9, 323–339, https://doi.org/10.5194/se-9-323-2018, https://doi.org/10.5194/se-9-323-2018, 2018
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Since 2002, the GRACE mission provides estimates of the Earth's time-variable gravity field, from which one can derive ocean mass variability. Now that the GRACE mission has come to an end, it is especially important to find alternative ways for deriving ocean mass changes. For the first time, we use kinematic orbits of Swarm for computing ocean mass time series. We compute monthly solutions, but also show an alternative way of directly estimating time-variable spherical harmonic coefficients.
Khandu, Joseph L. Awange, and Ehsan Forootan
Atmos. Meas. Tech., 9, 1685–1699, https://doi.org/10.5194/amt-9-1685-2016, https://doi.org/10.5194/amt-9-1685-2016, 2016
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Monthly accumulated COSMIC RO data is used to examine the interannual variability of UTLS temperature over the Ganges-Brahmaputra-Meghna river basin from 2006 to 2013. PCA analysis of tropopause temperatures and heights indicates that ENSO accounts for 73% of the interannual variability with a correlation of 0.77 with Niño3.4 index whereas the QBO explains about 10% of the variability. The tropopause temperature (height) increased (decreased) by about 1.5oC (300 m) during the 2009/2010 El Niño.
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To predict the satellite's motion or its re-entry, the density surrounding the satellite needs to be known as precisely as possible. Usually empirical models are used to estimate the neutral density of the thermosphere, which is the region of the neutrally charged atmosphere. Here, based on calibrated accelerations measured by instruments on board satellites, we compute daily global maps to correct modeled densities. During times of high solar activity, corrections of up to 28 % are necessary.
To predict the satellite's motion or its re-entry, the density surrounding the satellite needs...