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Bagherbandi, Mohammad, ProfessorORCID iD iconorcid.org/0000-0003-0910-0596
Publikasjoner (10 av 61) Visa alla publikasjoner
Amin, H., Sjöberg, L. E. & Bagherbandi, M. (2020). A global vertical datum defined by the conventional geoid potentialand the Earth ellipsoid parameters. In: : . Paper presented at EGU General Assembly 2020, Vienna, Austria, 3-8 May.
Åpne denne publikasjonen i ny fane eller vindu >>A global vertical datum defined by the conventional geoid potentialand the Earth ellipsoid parameters
2020 (engelsk)Konferansepaper, Oral presentation with published abstract (Annet (populærvitenskap, debatt, mm))
Abstract [en]

According to the classical Gauss–Listing definition, the geoid is the equipotential surface of the Earth’s gravity field that in a least-squares sense best fits the undisturbed mean sea level. This equipotential surface, except for its zero-degree harmonic, can be characterized using the Earth’s Global Gravity Models (GGM). Although nowadays, the satellite altimetry technique provides the absolute geoid height over oceans that can be used to calibrate the unknown zero-degree harmonic of the gravimetric geoid models, this technique cannot be utilized to estimate the geometric parameters of the Mean Earth Ellipsoid (MEE). In this study, we perform joint estimation of W0, which defines the zero datum of vertical coordinates, and the MEE parameters relying on a new approach and on the newest gravity field, mean sea surface, and mean dynamic topography models. As our approach utilizes both satellite altimetry observations and a GGM model, we consider different aspects of the input data to evaluate the sensitivity of our estimations to the input data. Unlike previous studies, our results show that it is not sufficient to use only the satellite componentof a quasi-stationary GGM to estimate W0. In addition, our results confirm a high sensitivity of the applied approach to the altimetry-based geoid heights, i.e. mean sea surface and mean dynamic topography models. Moreover, as W0 should be considered a quasi-stationary parameter, we quantify the effect of time-dependent Earth’s gravity field changes as well as the time-dependent sea-level changes on the estimation of W0. Our computations resulted in the geoid potential W0 = 62636848.102 ± 0.004 m2s-2 and the semi-major and –minor axes of the MEE,a = 6378137.678 ± 0.0003 m and b = 6356752.964 ± 0.0005 m, which are 0.678 and 0.650 m larger than those axes of the GRS80 reference ellipsoid, respectively. Moreover, a new estimation for the geocentric gravitational constant was obtained as GM = (398600460.55 ± 0.03) × 106 m3s-2.

HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-31485 (URN)
Konferanse
EGU General Assembly 2020, Vienna, Austria, 3-8 May
Tilgjengelig fra: 2020-01-18 Laget: 2020-01-18 Sist oppdatert: 2020-03-04bibliografisk kontrollert
Bagherbandi, M. & Gido, N. A. A. (2020). How isostasy explains continental rifting in East Africa?. In: : . Paper presented at EGU General Assembly 2020, Vienna, Austria, 3-8 May.
Åpne denne publikasjonen i ny fane eller vindu >>How isostasy explains continental rifting in East Africa?
2020 (engelsk)Konferansepaper, Poster (with or without abstract) (Annet (populærvitenskap, debatt, mm))
Abstract [en]

The principle of isostasy plays an important role to understand the relation between different geodynamic processes. Although, it is difficult to find an exact method that delivers a complete image of the Earth structure. However, gravimetric methods are alternative to provide images of the interior of the Earth. The Earth’s crust parameters, i.e. crustal depth and crust-mantle density contrast, can reveal adequate information about the solid Earth system such as volcanic activity, earthquake and continental rifting. Hence, in this study, a combine Moho model using seismic and gravity data is determined to investigate the relationship between the isostatic state of the lithosphere and seismic activities in East Africa. Our results show that isostatic equilibrium and compensation states are closely correlated to the seismicity patterns in the study area. For example, several studies suggest that African superplume causes the rift valley, and consequently differences in crustal and mantle densities occur. This paper presents a method to determine the crustal thickness and crust-mantle density contrast and consequently one can observe low-density contrast (about 200 kg/m3 ) and thin crust (about 30 km) near the triple junction plate tectonics in East Africa (Afar Triangle), which confirms the state of overcompensation in the rift valley areas. Furthermore, the density structure of the lithosphere shows a large correlation with the earthquake activity, sub-crustal stress and volcanic distribution across East Africa.

HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-31487 (URN)
Konferanse
EGU General Assembly 2020, Vienna, Austria, 3-8 May
Tilgjengelig fra: 2020-01-18 Laget: 2020-01-18 Sist oppdatert: 2020-01-20bibliografisk kontrollert
Amin, H., Bagherbandi, M. & Sjöberg, L. E. (2020). Quantifying barystatic sea-level change from satellite altimetry, GRACE and Argo observations over 2005–2016. Advances in Space Research, 65(8), 1922-1940
Åpne denne publikasjonen i ny fane eller vindu >>Quantifying barystatic sea-level change from satellite altimetry, GRACE and Argo observations over 2005–2016
2020 (engelsk)Inngår i: Advances in Space Research, ISSN 0273-1177, E-ISSN 1879-1948, Vol. 65, nr 8, s. 1922-1940Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Time-varying spherical harmonic coefficients determined from the Gravity Recovery and Climate Experiment (GRACE) data provide a valuable source of information about the water mass exchange that is the main contributor to the Earth’s gravity field changes within a period of less than several hundred years. Moreover, by measuring seawater temperature and salinity at different layers of ocean depth, Argo floats help to measure the steric component of global mean sea level (GMSL). In this study, we quantify the rate of barystatic sea-level change using both GRACE RL05 and RL06 monthly gravity field models and compare the results with estimates achieved from a GMSL budget closure approach. Our satellite altimetry-based results show a trend of 3.90 ± 0.14 mm yr−1 for the GMSL rise. About 35% or 1.29 ± 0.07 mm yr−1 of this rate is caused by the thermosteric contribution, while the remainder is mainly due to the barystatic contribution. Our results confirm that the choice of decorrelation filters does not play a significant role in quantifying the global barystatic sea-level change, and spatial filtering may not be needed. GRACE RL05 and RL06 solutions result in the barystatic sea-level change trends of 2.19 ± 0.13 mm yr−1 and 2.25 ± 0.16 mm yr−1, respectively. Accordingly, the residual trend, defined as the difference between the altimetry-derived GMSL and sum of the steric and barystatic components, amounts to 0.51 ± 0.51 and 0.45 ± 0.44 mm yr−1 for RL05 and RL06-based barystatic sea-level changes, respectively, over January 2005 to December 2016. The exclusion of the halosteric component results in a lower residual trend of about 0.36 ± 0.46 mm yr−1 over the same period, which suggests a sea-level budget closed within the uncertainty. This could be a confirmation on a high level of salinity bias particularly after about 2015. Moreover, considering the assumption that the GRACE-based barystatic component includes all mass change signals, the rather large residual trend could be attributed to an additional contribution from the deep ocean, where salinity and temperature cannot be monitored by the current observing systems. The errors from various sources, including the model-based Glacial Isostatic Adjustment signal, independent estimation of geocenter motion that are not quantified in the GRACE solutions, as well as the uncertainty of the second degree of zonal spherical harmonic coefficients, are other possible contributors to the residual trend.

sted, utgiver, år, opplag, sider
Elsevier, 2020
Emneord
Climate change, Sea-level budget, Decorrelation, Barystatic sea-level change, Steric sea-level change
HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-31978 (URN)10.1016/j.asr.2020.01.029 (DOI)2-s2.0-85079432165 (Scopus ID)
Merknad

Funding: CSIRO, NASA, NOAA

Tilgjengelig fra: 2020-03-02 Laget: 2020-03-02 Sist oppdatert: 2020-03-20bibliografisk kontrollert
Gido, N. A. A., Amin, H., Bagherbandi, M. & Nilfouroushan, F. (2020). Satellite monitoring of mass changes and ground subsidence in Sudan’s oil fields using GRACE and Sentinel-1 data. In: : . Paper presented at EGU General Assembly 2020, Vienna, Australia, 3-8 May.
Åpne denne publikasjonen i ny fane eller vindu >>Satellite monitoring of mass changes and ground subsidence in Sudan’s oil fields using GRACE and Sentinel-1 data
2020 (engelsk)Konferansepaper, Oral presentation with published abstract (Annet (populærvitenskap, debatt, mm))
Abstract [en]

Monitoring environmental hazards, due to natural and anthropogenic causes, is one of the important issues, which requires proper data, models, and cross-validation of the results. The geodetic satellite missions, e.g. the Gravity Recovery and Climate Experiment (GRACE) and Sentinel-1, are very useful in this aspect. GRACE missions are dedicated to model the temporal variations of the Earth’s gravity field and mass transportation in the Earth’s surface, whereas Sentinel-1 collects Synthetic Aperture Radar (SAR) data which enables us to measure the ground movements accurately. Extraction of large volumes of water and oil decreases the reservoir pressure, form compaction and consequently land subsidence occurs which can be analyzed by both GRACE and Sentinel-1 data. In this paper, large-scale groundwater storage (GWS) changes are studied using the GRACE monthly gravity field models together with different hydrological models over the major oil reservoirs in Sudan, i.e. Heglig, Bamboo, Neem, Diffra and Unity-area oil fields. Then we correlate the results with the available oil wells production data for the period of 2003-2012. In addition, using the only freely available Sentinel-1 data, collected between November 2015 and April 2019, the ground surface deformation associated with this oil and water depletion is studied. Due to the lack of terrestrial geodetic monitoring data in Sudan, the use of GRACE and Sentinel-1 satellite data is very valuable to monitor water and oil storage changes and their associated land subsidence over our region of interest. Our results show that there is a significant correlation between the GRACE-based GWS change and extracted oil and water volumes. The trend of GWS changes due to water and oil depletion ranged from -18.5 to -6.2mm/year using the CSR GRACE monthly solutions and the best tested hydrological model in this study. Moreover, our Sentinel-1 SAR data analysis using Persistent Scatterer Interferometry (PSI) method shows high rate of subsidence i.e. -24.5, -23.8, -14.2 and -6 mm/year over Heglig, Neem, Diffra and Unity-area oil fields respectively. The results of this study can help us to control the integrity and safety of operations and infrastructure in that region, as well as to study the groundwater/oil storage behavior.

HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-31486 (URN)
Konferanse
EGU General Assembly 2020, Vienna, Australia, 3-8 May
Tilgjengelig fra: 2020-01-18 Laget: 2020-01-18 Sist oppdatert: 2020-01-20bibliografisk kontrollert
Gido, N. A. A., Amin, H., Bagherbandi, M. & Nilfouroushan, F. (2020). Satellite monitoring of mass changes and ground subsidence in Sudan’s oil fields using GRACE and Sentinel-1 data. In: : . Paper presented at EGU General Assembly 2020, Vienna, Austria, 3-8 May.
Åpne denne publikasjonen i ny fane eller vindu >>Satellite monitoring of mass changes and ground subsidence in Sudan’s oil fields using GRACE and Sentinel-1 data
2020 (engelsk)Konferansepaper, Oral presentation with published abstract (Annet (populærvitenskap, debatt, mm))
Abstract [en]

Monitoring environmental hazards, due to natural and anthropogenic causes, is one of the important issues, which requires proper data, models, and cross-validation of the results. The geodetic satellite missions, e.g. the Gravity Recovery and Climate Experiment (GRACE) and Sentinel-1, are very useful in this aspect. GRACE missions are dedicated to model the temporal variations of the Earth’s gravity field and mass transportation in the Earth’s surface, whereas Sentinel-1 collects Synthetic Aperture Radar (SAR) data which enables us to measure the ground movements accurately. Extraction of large volumes of water and oil decreases the reservoir pressure, form compaction and consequently land subsidence occurs which can be analyzed by both GRACE and Sentinel-1 data. In this paper, large-scale groundwater storage (GWS) changes are studied using the GRACE monthly gravity field models together with different hydrological models over the major oil reservoirs in Sudan, i.e. Heglig, Bamboo, Neem, Diffra and Unity-area oil fields. Then we correlate the results with the available oil wells production data for the period of 2003-2012. In addition, using the only freely available Sentinel-1 data, collected between November 2015 and April 2019, the ground surface deformation associated with this oil and water depletion is studied. Due to the lack of terrestrial geodetic monitoring data in Sudan, the use of GRACE and Sentinel-1 satellite data is very valuable to monitor water and oil storage changes and their associated land subsidence over our region of interest. Our results show that there is a significant correlation between the GRACE-based GWS change and extracted oil and water volumes. The trend of GWS changes due to water and oil depletion ranged from -18.5 to -6.2mm/year using the CSR GRACE monthly solutions and the best tested hydrological model in this study. Moreover, our Sentinel-1 SAR data analysis using Persistent Scatterer Interferometry (PSI) method shows high rate of subsidence i.e. -24.5, -23.8, -14.2 and -6 mm/year over Heglig, Neem, Diffra and Unity-area oil fields respectively. The results of this study can help us to control the integrity and safety of operations and infrastructure in that region, as well as to study the groundwater/oil storage behavior.

HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-31902 (URN)
Konferanse
EGU General Assembly 2020, Vienna, Austria, 3-8 May
Tilgjengelig fra: 2020-02-18 Laget: 2020-02-18 Sist oppdatert: 2020-02-18bibliografisk kontrollert
Amin, H., Sjöberg, L. & Bagherbandi, M. (2019). A global vertical datum defined by the conventional geoid potential and the Earth ellipsoid parameters. Journal of Geodesy, 93(10), 1943-1961
Åpne denne publikasjonen i ny fane eller vindu >>A global vertical datum defined by the conventional geoid potential and the Earth ellipsoid parameters
2019 (engelsk)Inngår i: Journal of Geodesy, ISSN 0949-7714, E-ISSN 1432-1394, Vol. 93, nr 10, s. 1943-1961Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The geoid, according to the classical Gauss–Listing definition, is, among infinite equipotential surfaces of the Earth’s gravity field, the equipotential surface that in a least squares sense best fits the undisturbed mean sea level. This equipotential surface, except for its zero-degree harmonic, can be characterized using the Earth’s global gravity models (GGM). Although, nowadays, satellite altimetry technique provides the absolute geoid height over oceans that can be used to calibrate the unknown zero-degree harmonic of the gravimetric geoid models, this technique cannot be utilized to estimate the geometric parameters of the mean Earth ellipsoid (MEE). The main objective of this study is to perform a joint estimation of W0, which defines the zero datum of vertical coordinates, and the MEE parameters relying on a new approach and on the newest gravity field, mean sea surface and mean dynamic topography models. As our approach utilizes both satellite altimetry observations and a GGM model, we consider different aspects of the input data to evaluate the sensitivity of our estimations to the input data. Unlike previous studies, our results show that it is not sufficient to use only the satellite-component of a quasi-stationary GGM to estimate W0. In addition, our results confirm a high sensitivity of the applied approach to the altimetry-based geoid heights, i.e., mean sea surface and mean dynamic topography models. Moreover, as W0 should be considered a quasi-stationary parameter, we quantify the effect of time-dependent Earth’s gravity field changes as well as the time-dependent sea level changes on the estimation of W0. Our computations resulted in the geoid potential W0 = 62636848.102 ± 0.004 m2 s−2 and the semi-major and minor axes of the MEE, a = 6378137.678 ± 0.0003 m and b = 6356752.964 ± 0.0005 m, which are 0.678 and 0.650 m larger than those axes of GRS80 reference ellipsoid, respectively. Moreover, a new estimation for the geocentric gravitational constant was obtained as GM = (398600460.55 ± 0.03) × 106 m3 s−2.

Emneord
Geodetic reference system, Geoid potential W0, Global vertical datum, Mean Earth ellipsoid, Reference ellipsoid
HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-30666 (URN)10.1007/s00190-019-01293-3 (DOI)000495245100009 ()2-s2.0-85073812763 (Scopus ID)
Tilgjengelig fra: 2019-09-19 Laget: 2019-09-19 Sist oppdatert: 2019-11-28bibliografisk kontrollert
Gido, N. A. A., Bagherbandi, M. & Sjöberg, L. E. (2019). A gravimetric method to determine horizontal stress field due to flow in the mantle in Fennoscandia. Geosciences Journal, 23(3), 377-389
Åpne denne publikasjonen i ny fane eller vindu >>A gravimetric method to determine horizontal stress field due to flow in the mantle in Fennoscandia
2019 (engelsk)Inngår i: Geosciences Journal, ISSN 1226-4806, Vol. 23, nr 3, s. 377-389Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Mass changes and flow in the Earth's mantle causes the Earth's crust not only to movevertically, but also horizontally and to tilt, and produce a major stress in the lithosphere.Here we use a gravimetric approach to model sub-lithosphere horizontal stress in theEarth's mantle and its temporal changes caused by geodynamical movements likemantle convection in Fennoscandia. The flow in the mantle is inferred from tectonicsand convection currents carrying heat from the interior of the Earth to the crust. Theresult is useful in studying how changes of the stress influence the stability of crust.The outcome of this study is an alternative approach to studying the stress and itschange using forward modelling and the Earth's viscoelastic models. We show that thedetermined horizontal stress using a gravimetric method is consistent with tectonicsand seismic activities. In addition, the secular rate of change of the horizontal stress,which is within 95 kPa/year, is larger outside the uplift dome than inside.

sted, utgiver, år, opplag, sider
Springer, 2019
Emneord
horizontal stress, mantle convection, mass change, stress field, tectonics
HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-27317 (URN)10.1007/s12303-018-0046-8 (DOI)000469221700002 ()2-s2.0-85054552297 (Scopus ID)
Tilgjengelig fra: 2018-06-24 Laget: 2018-06-24 Sist oppdatert: 2019-08-22bibliografisk kontrollert
Amin, H., Bagherbandi, M. & Sjöberg, L. E. (2019). Evaluation of the Closure of Global Mean Sea Level Rise Budget over January 2005 to August 2016. In: : . Paper presented at 27th IUGG General Assembly, 8-18 July, 2019, Montreal, Canada, Session title: JG06 - Posters - Monitoring Sea Level Changes by Satellite and In-Situ Measurements (IAG, IAPSO).
Åpne denne publikasjonen i ny fane eller vindu >>Evaluation of the Closure of Global Mean Sea Level Rise Budget over January 2005 to August 2016
2019 (engelsk)Konferansepaper, Poster (with or without abstract) (Annet (populærvitenskap, debatt, mm))
Abstract [en]

Sea level changes over time because of water mass exchange among the oceans and continents, ice sheets, and atmosphere. It fluctuates also due to variations of seawater salinity and temperature known as the steric contributor. GRACE-based Stokes coefficients provide a valuable source of information, about the water mass exchange as the main contributor to the Earth’s gravity field changes, within decadal scales. Moreover, measuring seawater temperature and salinity at different layers of ocean depth, Argo floats help to model the steric component of Global Mean Sea Level. In this study, we evaluate the Global Mean Sea Level (GMSL) budget closure using satellite altimetry, GRACE, and Argo products. Hereof, considering the most recent released GRACE monthly products (RL06), we examine an iterative remove-restore method to minimize the effect of artifact leaked large signal from ice sheets and land hydrology. In addition, the effect of errors and biases in geophysical model corrections, such as GIA, on the GMSL budget closure is estimated. Moreover, we quantify the influence of spatial and decorrelation filtering of GRACE data on the GMSL budget closure. In terms of the monthly fluctuations of sea level, our results confirm that closing the GMSL budget is highly dependent on the choice of the spatial averaging filter. In addition, comparing the trends and variations for both the global mean sea level time series and those estimated for mass and steric components, we find that spatial averaging functions play a significant role in the sea level budget closure.

HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-31481 (URN)
Konferanse
27th IUGG General Assembly, 8-18 July, 2019, Montreal, Canada, Session title: JG06 - Posters - Monitoring Sea Level Changes by Satellite and In-Situ Measurements (IAG, IAPSO)
Merknad

https://www.czech-in.org/cmPortalV15/CM_W3_Searchable/iugg19/normal#!abstractdetails/0000740790

Tilgjengelig fra: 2020-01-18 Laget: 2020-01-18 Sist oppdatert: 2020-01-20bibliografisk kontrollert
Gido, N. A. A., Bagherbandi, M., Sjöberg, L. E. & Tenzer, R. (2019). Studying permafrost by integrating satellite and in situ data in the northern high-latitude regions. Acta Geophysica, 67(2), 721-734
Åpne denne publikasjonen i ny fane eller vindu >>Studying permafrost by integrating satellite and in situ data in the northern high-latitude regions
2019 (engelsk)Inngår i: Acta Geophysica, ISSN 1895-6572, E-ISSN 1895-7455, Vol. 67, nr 2, s. 721-734Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

There is an exceptional opportunity of achieving simultaneous and complementary data from a multitude of geoscience and environmental near-earth orbiting artificial satellites to study phenomena related to the climate change. These satellite missions provide the information about the various phenomena, such as sea level change, ice melting, soil moisture variation, temperature changes and earth surface deformations. In this study, we focus on permafrost thawing and its associated gravity change (in terms of the groundwater storage), and organic material changes using the gravity recovery and climate experiment (GRACE) data and other satellite- and ground-based observations. The estimation of permafrost changes requires combining information from various sources, particularly using the gravity field change, surface temperature change, and glacial isostatic adjustment. The most significant factor for a careful monitoring of the permafrost thawing is the fact that this process could be responsible for releasing an additional enormous amount of greenhouse gases emitted to the atmosphere, most importantly to mention carbon dioxide (CO2) and methane that are currently stored in the frozen ground. The results of a preliminary numerical analysis reveal a possible existence of a high correlation between the secular trends of greenhouse gases (CO2), temperature and equivalent water thickness (in permafrost active layer) in the selected regions. Furthermore, according to our estimates based on processing the GRACE data, the groundwater storage attributed due to permafrost thawing increased at the annual rates of 3.4, 3.8, 4.4 and 4.0 cm, respectively, in Siberia, North Alaska and Canada (Yukon and Hudson Bay). Despite a rather preliminary character of our results, these findings indicate that the methodology developed and applied in this study should be further improved by incorporating the in situ permafrost measurements.

sted, utgiver, år, opplag, sider
Springer, 2019
Emneord
Climate change, Permafrost, Gravity, Grace, Greenhouse gas
HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-29393 (URN)10.1007/s11600-019-00276-4 (DOI)000463780000022 ()2-s2.0-85062782688 (Scopus ID)
Tilgjengelig fra: 2019-03-18 Laget: 2019-03-18 Sist oppdatert: 2019-11-25bibliografisk kontrollert
Bagherbandi, M., Gido, N. A. A., Sjöberg, L. E. & Tenzer, R. (2019). Studying permafrost using GRACE and in situ data in the northern high-latitudes regions. In: : . Paper presented at 27th IUGG General Assembly, 8-18 July, 2019, Montreal, Canada, Session title: G03 - Posters - Time-Variable Gravity Field.
Åpne denne publikasjonen i ny fane eller vindu >>Studying permafrost using GRACE and in situ data in the northern high-latitudes regions
2019 (engelsk)Konferansepaper, Poster (with or without abstract) (Annet (populærvitenskap, debatt, mm))
Abstract [en]

There is an exceptional opportunity of achieving simultaneous and complementary data from a multitude of geoscience and environmental near-earth orbiting artificial satellites to study phenomena related to the climate change e.g. sea level change, ice melting, soil moisture variation, temperature changes, and earth surface deformations. In this study, we focus on permafrost thawing and its associated gravity change, and organic material changes using GRACE data and other satellite- and ground-based observations. The estimation of permafrost changes requires combining information from various sources, particularly using the gravity field change, surface temperature change, and GIA. The most significant factor for careful monitoring of the permafrost thawing is the fact that this process could be responsible for releasing an additional enormous amount of greenhouse gases emitted to the atmosphere, most importantly to mention Carbone dioxide and Methane that are currently stored in the frozen ground. The results of a preliminary numerical analysis reveal a possible existence of a high correlation between the secular trends of greenhouse gases, temperature and equivalent water thickness in the selected regions. Furthermore, according to our estimates based on processing the GRACE data, the groundwater storage attributed to the due to permafrost thawing increased at the annual rates of 3.4, 3.8, 4.4 and 4.0 cm, in Siberia, northern Alaska, and Canada. Despite a rather preliminary character of our results, these findings indicate that the methodology developed and applied in this study should be improved by incorporating the in situ permafrost measurements.

HSV kategori
Identifikatorer
urn:nbn:se:hig:diva-31480 (URN)
Konferanse
27th IUGG General Assembly, 8-18 July, 2019, Montreal, Canada, Session title: G03 - Posters - Time-Variable Gravity Field
Merknad

https://www.czech-in.org/cmPortalV15/CM_W3_Searchable/iugg19/normal#!abstractdetails/0000723120

Tilgjengelig fra: 2020-01-18 Laget: 2020-01-18 Sist oppdatert: 2020-01-20bibliografisk kontrollert
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-0910-0596