Space weather forecasters perspective: UK David Jackson and Mark Gibbs SEREN Bz workshop, Abingdon, 9-10 July 2014

Overview Met Office Space Weather Operations Centre (MOSWOC) Customers interested in Bz What we do now for CME / Bz forecasts WSA Enlil and ACE Forecast Improvements More observations Improved modelling magnetospheric coupling

© Crown copyright Met Office Met Office Space Weather Operations Centre Embedded in Met Office Hazard Centre 24x7x365 – 29 April’14 Full capability autumn ‘14 Collaborate with academia not replicate Operational collaboration with NOAA SWPC & BGS Daily forecast coordination Add UK-centric advice and impacts

© Crown copyright Met Office Met Office Bz Customers UK Government Space Weather placed on NRR Impact on power grid National Grid Ideal user requirement: CME arrival time and Bz magnitude and orientation >~5 days before the event

How we do CME forecasts / alerts now WSA Enlil model: CME arrival times but no Bz ACE data Bz but short lead times Identification of active regions can be used by NG as prompt for mitigative action

© Crown copyright Met Office WSA Enlil model Purpose: Models solar wind speed & density from Sun to Earth (IMF modelled but no Bz input). Predicts CME arrival times at Earth, Inputs: WSA uses solar magnetograms to model coronal magnetic field and provide inner BCs for Enlil. CME analysis tools (NASA StereoCAT or NOAA CAT) calculate CME parameters using fit to STEREO A&B and LASCO images. CME parameters input into Enlil Output: Run every 2hrs Forecasts: average error: +_ 7 hrs (Doug Biesecker); lead time: CME transit time – a few hrs

© Crown copyright Met Office ACE data: Magnetometer – 1 min cadence, ~3 mins latency SWEPAM density, proton temp, speed - 1 min cadence, 2-3 mins latency 24/7 Monitoring so warning time ~same as L1 to Earth transit time (~20-45 mins)

Forecast Improvements What we need longer lead time Bz forecasts but improved arrival time estimates are still important, too coupling to magnetosphere How we might get this More observations: L1 and beyond; IPS Better models: WSA replacement, ensembles

© Crown copyright Met Office ACE is old – important to have a backup: DSCOVR – L1 mission planned launch January 2015 Sunjammer: NASA Technology Demonstration Mission Pass through L1 to 2 x L1 Cubesat sensors - very much technology demo Magnetometer (MAGIC) + Solar Wind ANalyser (SWAN) Launch expected ? Bz warning times doubled, but only to ~40-90 mins Space Weather Diamond (see earlier talk) Bz warning times 10 x L1: ~3 ½ - 7 ½ hrs More Observations: L1 and beyond

© Crown copyright Met Office Better solar wind forecasts: WSA replacement – UCSD/KWSC (+ MetO/RAL?) DA in Enlil domain Bz inference from Faraday rotation Bz warning times 10 x L1: ~3 ½ - 7 ½ hrs Same as Space Weather Diamond Harder science challenges but benefits in terms of cost, more rapid availability Also system robustness More Observations : IPS WSA IPS Dusan Odstrcil Absence of STEREO highlights (over)reliance on STEREO & LASCO Need to extend WSA Enlil to include other obs types IPS - Ground based system:

NLFF model instead of WSA Simulations of lower coronal magnetic field driven by sequences of magnetogram obs (Mackay & Yeates) Time dependent - can follow the build-up of “free” magnetic energy that is known to drive space weather events (but is not in WSA (static extrapolation)) New work with Met Office focuses on impacts on space weather forecasts eg Comparison of predictions of ambient IMF with WSA Add current-sheet extension at the outer radial boundary model to provide predictions of the latitude of the heliospheric current sheet, and hence the IMF polarity at any given time.

NLFF model may be pathway to Bz forecasts Might be scope to use observations + NLFF model to infer Bz (Lucie’s talk) Enlil’s formulation may mean it may not retain Bz information well – use other (MHD) model like AMRVAC? Limited operational testing of AMRVAC and doubts on computational expense of model – this could more than offset positive benefit of science results

Coupling to Magnetosphere Translates global Earth impacts to regional scales Input into eg GIC model of GB power grid More detailed assessments for users Apps (eg GIC models) Solar wind (incl BZ)

Summary Current WSA Enlil forecasts don’t do Bz – best Bz warnings are from ACE with minutes lead time We should exploit new space missions (Sunjammer, Diamond) to increase lead time, but also other, non- space data (chiefly IPS) NLFF model developments may offer scope for better Bz initialisations, but need to understand how these are modelled in the heliosphere Haven’t begun to do any magnetospheric work, but coupling of the region with solar wind key to better regional forecasts