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The Daedalus Ionospheric Profile Continuation (DIPCont) project is concerned with the question how in situ measurements in the lower thermosphere and ionosphere (LTI) can be extrapolated using parametric models of observables and derived variables. To reflect the pronounced change of temperature across the LTI, non-isothermal models for neutral density and also electron density are constructed from scale height profiles that increase linearly with altitude. Ensembles of model parameters are created by means of Monte Carlo simulations using synthetic measurements based on model predictions and relative uncertainties as specified in the Daedalus Report for Assessment. The parameter ensembles give rise to ensembles of model altitude profiles for LTI variables of interest. Extrapolation quality is quantified by statistics derived from the altitude profile ensembles. The vertical extent of meaningful profile continuation is captured by the concept of extrapolation horizons defined as the boundaries of regions where the deviations remain below a prescribed error threshold. The methodology allows for assessing how cost-critical elements of the Daedalus mission proposal such as perigee and apogee distances as major factors controling the necessary amount of propellant and radiation shielding, respectively, affect the accuracy of scientific inference in the LTI. First results are presented for dual-satellite measurements at different inter-spacecraft distances but also for the single-satellite case to compare the two basic mission scenarios under consideration. DIPCont models and procedures are implemented in a collection of Python modules and Jupyter notebooks supplementing this report. [ABSTRACT FROM AUTHOR] more...

Geomagnetic disturbances at the Earth are mainly driven by two large-scale solar windstructures. Of most relevance to space weather are interplanetary manifestations ofcoronal mass ejections (ICMEs), their associated shocks, sheaths, magnetic cloudsand ejecta. The second driver are co-rotating interaction regions (CIRs), togetherwith recurring high speed streams. These structures have characteristic solar windspeed (v), magnetic field (Bsw), plasma and compositional signatures, which canbe identified in-situ by near-Earth satellite measurements (e.g. Wind, ACE). Asgeomagnetic activity responds closely to v ⋅ Bsw,z ("driving electrical field"), ICMEs andCIRs trigger different signatures in activity indices derived from ground-basedmagnetometer measurements (e.g. Dst). Spanning more than 10 solar cycles, geomagneticobservatory time series offer a quantitative (statistical) approach to the identificationof geomagnetic storm drivers in addition to the qualitative one based on satellitedata.We present a feasibility study investigating the capability of geomagnetic observatory data topredict geomagnetic storm drivers in the past, prior to the satellite era. Our analysis is basedon the Hourly Magnetospheric Currents (HMC) index (Pick et al., JGR, under revision) andthe underlying observatory time series. HMC’s correct absolute level and the high power atlow frequencies, especially at the 11-year period, justify its preference over other indices.First, geomagnetic storm events are identified based on a HMC threshold, scaled according tothe solar cycle phase (target set, since 1930). Secondly, events with known drivers aregathered from the literature (training set, since 1995) and superposed at HMC peak times inorder to identify distinguishing model features. These are derived from five basicproperties: (1) HMC, (2) dHMC/dt, (3) B(MLT) - the main magnetic field disturbance independence on magnetic local time, (4) dB∕dt and (5) ASYdd - the difference in B atdawn (6 MLT) and dusk (18 MLT). Lastly, the binary classification problem, 0:CIR-driven or 1: CME-driven, is solved by training and cross-validating a logisticregression model on the training set. The prediction step is subsequently applied to thetarget set, yielding the driver class and its probability for each event. We assessthe capability of the classifier and discuss, whether our findings can contributebeyond an application in the past to the study of geomagnetic storm drivers today. [ABSTRACT FROM AUTHOR] more...