Difference between pages "IC SG5" and "JSG T.33"

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<big>'''JSG 0.5: Multi-sensor combination for the separation of integral
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<big>'''JSG 0.20: Space weather and ionosphere'''</big>
geodetic signals'''</big>
 
  
Chair: ''F. Seitz (Germany)''<br>
+
Chair: '': Klaus Börger (Germany)''<br>
Affiliation: ''Comm. 2, 3 and GGOS''
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Affiliation:''Commissions 1, 4 and GGOS''
  
 
__TOC__
 
__TOC__
===Objectives===
 
  
A large part of the geodetic parameters derived from space geodetic observation techniques are integral quantities of the Earth system. Among the most prominent ones are parameters related to Earth rotation and the gravity field. Variations of those parameters reflect the superposed effect of a multitude of dynamical processes and interactions in various subsystems of the Earth. The integral geodetic quantities provide fundamental and unique information for different balances in the Earth system, in particular for the balances of mass and angular momentum that are directly related to (variations of) the gravity field and Earth rota-tion. In respective balance equations the geodetic para-meters describe the integral effect of exchange processes of mass and angular momentum in the Earth system. In contrast to many other disciplines of geosciences, geodesy is characterized by a very long observation history. Partly, the previously mentioned parameters have been deter-mined over many decades with continuously improved space observation techniques. Thus geodesy provides an excellent data base for the analysis of long term changes in the Earth system and contributes fundamentally to an improved understanding of large-scale processes.
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===Terms of Reference===
However, in general the integral parameter time series can-not be separated into contributions of specific processes without further information. Their separation and therewith their geophysical interpretation requires complementary data from observation techniques that are unequally sensi-tive for individual effects and/or from numerical models. Activities of the study group are focussed on the develop-ment of strategies for the separation of the integral geo-detic signals on the basis of modern space-based Earth observation systems. A multitude of simultaneously operating satellite systems with different objectives is available today. They offer a broad spectrum of informa-tion on global and regional-scale processes at different temporal resolutions. Within the study group it shall be investigated in which way the combination of heterogene-ous data sets allows for the quantification of individual contributors to the balances of mass and angular momen-tum.
 
The research activities shall be coordinated between the participating scientists and shall be conducted in interdisci-plinary collaboration. At all times the group is open for new contacts and members in order to embed the activities in a wide context. The study group is primarily affiliated with the IAG commissions 2 (Gravity field) and 3 (Earth rotation and geodynamics).
 
  
===Objectives===
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It is well known that space geodetic methods are under influence of ionospheric refraction, and therefore from the very beginning of these techniques geodesy deals with the ionosphere. In this context sophisticated methods and models have been developed in order to determine, to represent and to predict the ionosphere. Apart from this the ionosphere fits into another issue called „space weather“, which describes the interactions between the constituents of space and earth. To be more precise space weather means the conditions in space with a significant impact on space-based and ground-based technology as well as on earth and its inhabitants.  Solar radiation, that is electromagnetic emission as well as particle emission, is the main cause or “drive” of space weather.
  
The primary objective of the study group is the development of strategies for multi-sensor combinations with the aim of separating time series of integral geodetic para-meters related to Earth rotation and gravity field. The separation of the parameter time series into contributions of individual underlying effects fosters the understanding of dynamical processes and interactions in the Earth system. This is of particular interest in the view of global change.
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Originally, geodesy, or to be more precise, space geodetic methods have considered the ionosphere as a disturbing factor that affects signal propagation and that has to be corrected. This (geodetic) perspective has been changed over time and the ionosphere has become a target value so that geodetic observations are used to determine the ionosphere. Different groups have developed models of high quality, e.g. 3D-models which describe the ionosphere as a function of longitude, latitude and time or even 4D-models accounting for the height as well. However, since the ionosphere is a manifestation of space weather, geodesy should contribute to space weather research, and in this respect completely new scientific questions arise, in particular with respect to the so called “geo-effect”, which is the impact of space weather in general.
Individual contributions from various subsystems of the Earth shall be quantified and balanced. In particular our investigations focus on the separation of the Earth rotation parameters (polar motion and variations of length-of-day) into contributions of atmospheric and hydrospheric angular momentum variations, and on the separation of GRACE gravity field observations over continents into the contribu-tions of individual hydrological storage compartments, such as groundwater, surface water, soil moisture and snow.
 
Investigations in the frame of the study group will exploit the synergies of various observation systems (satellite alti-metry, optical and radar remote sensing, SMOS, and others) for the separation of the signals and combine their output with numerical models. Among the most important steps are compilation and assessment of background information for individual observation systems and sensors (mode of operation, sensitivity, accuracy, deficiencies) as well as theoretical studies which (new) information on the Earth system can be gained from a combination of differ-ent observation methods.
 
  
In particular the research comprises the following topics:
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There are two principal goals of the proposed study group. First, to connect the “geodetic” ionosphere research with solar-terrestrial physics, in order to consider the complete cause-effect-chain. Second, the above mentioned “geo-effect” has to be investigated in detail, which is an important aspect, because modern society depends to a great extent on technology, i.e. technology that can be disturbed, that can be harmed or that even can be destroyed by extreme space weather events
* potential und usability of contemporary space-borne and terrestrial sensors for an improved understanding of pro-cesses within atmosphere and hydrosphere.
 
* analysis of accuracy, temporal and spatial resolution and coverage of different data sets
 
* theoretical and numerical studies on the combination of heterogeneous observation types. This comprehends in-vestigations on appropriate methods for parameter esti-mation including error propagation, the analysis of linear dependencies between parameters and the solution of rank deficiency problems.
 
* mathematical methods for the enhancement of the infor-mation content (e.g. filters)
 
* quantification of variations of mass and angular momen-tum in different subsystems from multi-sensor analysis
 
* analysis of the consistencies of balances between individ-ual effects and integral geodetic parameters on different spatial scales
 
* formulation of recommendations for future research and (if possible) for future satellite missions on the basis of balance inconsistencies
 
  
===Planned Activities===
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===Objectives===
  
* Set-up of a SG webpage for dissemination of information (activities and a bibliographic list of references) and for presentation and communication of research results.
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* improvements and enlargements of ionosphere models (including scintillations)
* Organization of conference sessions / workshops:
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* geodetic contributions to investigate the impact of space weather/the ionosphere (extreme events) on satellite motion
** planned in 2013: Conference Session in the Hotine Marussi Symposium
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* geodetic contributions to investigate the impact of space weather/the ionosphere (extreme events) on communication
** planned in 2014: 2nd workshop on the Quality of Geo-detic Observing and Monitoring Systems (QuGOMS’ 14)
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* investigations of the impact of space weather/the ionosphere (extreme events) on remote sensing products
* Common publications of SG members
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* investigations of the impact of space weather/the ionosphere (extreme events) on terrestrial technical infrastructure (metallic networks, power grids)
* Common fund raising activities (e.g. for PhD positions)
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* “geodetic observations” of currents (ring current, electrojets)
  
===Principal Scientific Outcome/Results===
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===Program of activities===
  
By the end of the 4-year period 2011-2015 the following outcome shall be achieved:
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* the maintaining of a website for general information as well as for internal exchange of data sets and results
Mature experience in geodetic multi-sensor data combina-tion including data availability, formats, combination strategies and accuracy aspects
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* organization of a workshop w.r.t. space weather and geo-effects
Numerical results for separated hydrological contributions to integral mass variations observed by GRACE for selected study areas.
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* publication of important findings
Numerical results for separated atmospheric/hydrospheric contributions Earth rotation parameters on seasonal to inter-annual time scales
 
Initiation of at least one common funded project with posi-tions for PhD students working in the topical field of the study group
 
  
===Members===
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===Membership===
  
'' '''Florian Seitz (Germany), chair'''<br />Sarah Abelen (Germany)<br />Rodrigo Abarca del Rio (Chile)<br />Andreas Güntner (Germany)
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'' '''Klaus Börger (Germany), chair''' <br /> Mahmut Onur Karsioglu (Turkey), vice-chair <br /> Michael Schmidt (Germany) <br /> Jürgen Matzka (Germany) <br /> Barbara Görres (Germany) <br /> George Zhizhao Liu (Hong Kong, China) <br /> Ehsan Forootan (Germany) <br /> Johannes Hinrichs (Germany) <br />''
<br />Karin Hedman (Germany)<br />Franz Meyer (USA)<br />Michael Schmidt (Germany)<br />Manuela Seitz (Germany)<br />Alka Singh (India)<br />''
 

Revision as of 09:15, 29 April 2016

JSG 0.20: Space weather and ionosphere

Chair: : Klaus Börger (Germany)
Affiliation:Commissions 1, 4 and GGOS

Terms of Reference

It is well known that space geodetic methods are under influence of ionospheric refraction, and therefore from the very beginning of these techniques geodesy deals with the ionosphere. In this context sophisticated methods and models have been developed in order to determine, to represent and to predict the ionosphere. Apart from this the ionosphere fits into another issue called „space weather“, which describes the interactions between the constituents of space and earth. To be more precise space weather means the conditions in space with a significant impact on space-based and ground-based technology as well as on earth and its inhabitants. Solar radiation, that is electromagnetic emission as well as particle emission, is the main cause or “drive” of space weather.

Originally, geodesy, or to be more precise, space geodetic methods have considered the ionosphere as a disturbing factor that affects signal propagation and that has to be corrected. This (geodetic) perspective has been changed over time and the ionosphere has become a target value so that geodetic observations are used to determine the ionosphere. Different groups have developed models of high quality, e.g. 3D-models which describe the ionosphere as a function of longitude, latitude and time or even 4D-models accounting for the height as well. However, since the ionosphere is a manifestation of space weather, geodesy should contribute to space weather research, and in this respect completely new scientific questions arise, in particular with respect to the so called “geo-effect”, which is the impact of space weather in general.

There are two principal goals of the proposed study group. First, to connect the “geodetic” ionosphere research with solar-terrestrial physics, in order to consider the complete cause-effect-chain. Second, the above mentioned “geo-effect” has to be investigated in detail, which is an important aspect, because modern society depends to a great extent on technology, i.e. technology that can be disturbed, that can be harmed or that even can be destroyed by extreme space weather events

Objectives

  • improvements and enlargements of ionosphere models (including scintillations)
  • geodetic contributions to investigate the impact of space weather/the ionosphere (extreme events) on satellite motion
  • geodetic contributions to investigate the impact of space weather/the ionosphere (extreme events) on communication
  • investigations of the impact of space weather/the ionosphere (extreme events) on remote sensing products
  • investigations of the impact of space weather/the ionosphere (extreme events) on terrestrial technical infrastructure (metallic networks, power grids)
  • “geodetic observations” of currents (ring current, electrojets)

Program of activities

  • the maintaining of a website for general information as well as for internal exchange of data sets and results
  • organization of a workshop w.r.t. space weather and geo-effects
  • publication of important findings

Membership

Klaus Börger (Germany), chair
Mahmut Onur Karsioglu (Turkey), vice-chair
Michael Schmidt (Germany)
Jürgen Matzka (Germany)
Barbara Görres (Germany)
George Zhizhao Liu (Hong Kong, China)
Ehsan Forootan (Germany)
Johannes Hinrichs (Germany)