David Jackson

Suzy Bingham, Emily Down, Siegfried Gonzi, Dan Griffin, Edmund Henley, James Manners, Mike Marsh

Towards Improved Operational Space Weather Forecasts – challenges in modelling and observations

European Space Weather Week, Leuven, Belgium, 5-9 November 2018@MetOfficeSpace

© Crown copyright Met Office

• Met Office strategic goal for operational space weather forecasts:

• coupled Sun to Earth modelling system. Physics-based, constrained by DA.

• In reality, still far away : no coupled system, only some DA, use of empirical (not physics-based) models remains commonplace.

• Gaps in this ideal future S2E system.

• List of scientific and technical challenges to be met

• Examples of ways to start to address the problems – heliosphere DA, development of whole atmosphere model

• Gaps in observation network – use WMO requirements to address this

• Helped guide design for new operational L1 and L5 solar / heliosphere missions

• Can be used in the design of a new observation network for the thermosphere.

2

Outline

•Photosphere(solar surface)

•Corona(solar atmosphere)

•Solar wind(interplanetary space)

•Magnetosphere•Radiation belts

• Ionosphere

•Thermosphere

• Middle and Lower atmosphere

Toward Sun-Earth coupled modelling

GOAL: Coupled Sun-to-Earth models with DA for much-enhanced forecast capacity

•CME prediction

•coronal magnetic field modelling

•What ARs shall be eruptive?

•Flare prediction, AR tracking

•CH and filament identification

•SEP initiation

•Ionosphericscintillation

•Thermosphere modelling

•Thermo / ionosphere coupling

•Upper / lower atmosphere coupling (whole atmosphere model)

•Aviation radiation

•Strength of storms / substorms

•No magnetosphere model !

•Radiation belt forecasts only at Geo

Opinion of MOSWOC Scientists, Forecasters, Managers

----------------------------------------------- No coupling ! ------------------------------------------

Sun-to-Earth modellingWhat’s missing?

•Bz prediction

•DA / IPS data

•SEP propagation

Solar / Heliosphere ChallengesProblem Next Step Physics? DA?

Coupling?

CME prediction - P?

Coronal magnetic field modelling

NLFFF magnetofriction

P, C

What ARS shall be eruptive?

- P?

Flare prediction, AR tracking

Ensembles,SMART

CH / filament identification

CHIMERA (CH)

SEP initialisation SPARX P

Bz prediction Faraday rotn?

DA / IPS data DA prototype, IPS Enlil

P, D, C(?),

SEP propagation SPARX P

Automated CH methods (CHIMERA: Tadhg Garton, TCD)

Lack of physical understanding and insufficient data??

Need more data?

• Heavy reliance on SEL, photosphericmagnetic field

• IPS and L5 operational mission good additions

• Parker SP and SO no good for ops but good for research => future opern. missions

Do more with existing data?

• Empirical CME / SEP prediction?

• Flares done to death but no step change –need a paradigm shift e.g more physics-based

models

Challenges nearer to EarthProblem Next Step Physics? DA? Coupling?

Strength of storms / substorms

No / SWMF P, C

No magnetospheremodel

SWMF P, C

Rad belt f/casts only at Geo

BAS model P, (C)

Ionosphericscintillation

-

Thermosphere modelling

DTM

Thermo / ionosphere modelling

UM / TIEGCM P, D, C

Upper / lower atmosphere coupling

UM (WA version)

P, (D), C

Aviation radiation MAIRE P

More physics-based models and DA

• Simple fact that ionosphere and quite a lot of the magnetosphere is fairly well observed?

• Still need model developments. Eg MHD->PiC for substorms, ionosphere / thermosphere / lower atmosphere coupling

• But still need more obs e.g away from Geo, whole of thermosphere. Scintillation, aviation-level radiation

© Crown copyright Met Office

Examples of ways we are addressing these gaps

Heliospheric DA

RMSE in near-Earth solar wind speed Blue = prior state, from the MAS ensemble. Green = posterior state, from DA of STEREO A and B .

• Need data ahead of Earth to improve forecasts at Earth

• But need to run model back in time to update inner boundary –otherwise information gets swept out beyond 1 AU by solar wind

•Lang et al (2017) showed that EnKF can’t work with Enlil for this reason

•Applying 4D-Var to 2D solar wind model (Riley & Lionello) much more successful (Lang et al, 2018) since adjoint updates previous model state

•Window = 27 days. Simple linear model (NWP = 6 hrs). What about for an MHD model? Matt Lang (Paris), Matt Owens

(Reading)

• One model from the Earth’s surface to exobase

• Important role of lower level driving in thermos / ionosphericstate

A Whole Atmosphere model

Extend UM from 85 km upto the thermosphere

• Its non-hydrostatic formulation will make the UM unique amongst surface to thermosphere-spanning models.

Chartier et al, 2013

Focus on upward extension to ~170 km first

• physics & chemistry schemes in development

• In meantime, relaxation to T climatology gives stable testbed (100 km lid; 120 km lid being worked on)

• Modify GW parametrization to work in MLT

• Molecular viscosity for realistic wave damping in thermosphere – enables lid > 130 km

Matt Griffith (Bath), Chris Kelly (Leeds)

© Crown copyright Met Office

WMO observations requirements and data gaps

WMO Space Weather Observing

Requirements

•Rolling requirements – observations for operational SpWXhttp://www.wmo-sat.info/oscar/applicationareas/view/25

• "threshold" – min.

requirement for

useful data

•"goal" - ideal

•"breakthrough" -

intermediate level.

An optimum, from

cost-benefit POV,

when planning or

designing obs

systems.

WMO Statement of Guidance: assessment of adequacy of

observations to fulfill requirements; suggests areas of progress

towards improved observing systems.

http://www.wmo.int/pages/prog/www/OSY/SOG/SoG-SW.pdf

Future L1 and L5 Missions

• WMO / Met Office requirements fed into

ESA Phase 0, and Phase 1 / 2A studies

• CME

Detection

strongly

dependent on

STEREO and

SOHO (L1)

c/graphs

• Way past

their planned

lifetimes

Observation Instrument Priority

Coronal imagery (CME detection) Coronagraph M(andatory)

Imaging of transients on SEL Heliospheric Imager M

Photospheric full disk

magnetograms

Magnetograph M

EUV imaging of coronal structures

and solar activity

EUV Imager M

Solar wind plasma measurement Plasma analyser M

IMF vector measurements Magnetometer M

X-ray flux measurement X-ray flux meter M

Radio burst detection Radio receivers S(econdary)

Energetic particles Proton and electron

detector

S

Proposed Instrument Baseline for L5 Mission

WMO Statement of Guidance & Gap Assessment

Lower thermosphere ρ - Less than Marginal / Marginal – (limb

sounding UV) SSUSI and SSULI may meet reqs, but no info available

on accuracy, obs cycle and timeliness

Upper thermosphere ρ - Marginal – Swarm meets some reqs (not

timeliness, uncertainty, vert. res.). Partly addressed by new missions

eg GRACE follow-on? SSUSI/SSULI may meet reqs.

Wind: Lower and upper thermosphere - Poor – Only a few sparse FPI

observations. Poor timeliness. Awaiting ICON mission in 2017.

Accelerometer wind errors too large.

T: Lower Thermosphere - Marginal – OSIRIS data are available, but they

do not cover whole vertical range and have poor timeliness. Upper

Thermosphere - Poor – just FPI

Layer U/certainty Hor res Vert res Ob cycle Timeliness

ρ Hi Thermo 10/15/20 % 100/200/500

km

20/50/100

km

5s / 5 min

/ 30 min

30/45/60 min

ρ Lower

Thermo

5/7/10 % 100/200/500

km

5/10/25

km

5s / 60 s /

5 min

5/20/60 min

Possible solution: Fill gaps with smallsat

constellations (after QB50)

QB50 Objective: to carry out atmospheric research within the

lower thermosphere, between 200 - 380km altitude.

Instruments include Ion-Neutral Mass Spectrometer (INMS): T, ρ

Constellation designed

to be closer to WMO

vertical resolution

requirements

•Use nanoracks to launch

cubesat batches (ISS,

415km) 60 days apart =>

leads to separation in

altitude of O(10) km

•Also 8 Cubesats at 500

km

To be addressed in future mission

•Timeliness poor (no QB50 data reception budget)

•Maintaining full coverage – initial orbits, replenishing

constellation, small onboard propulsion systemsSee Caspi et al, submitted to Space Weather

© Crown copyright Met Office

• Met Office strategic goal for operational space weather forecasts:

• Big gaps between state of the art and where we want to be

• Further model and DA developments are required. Some being worked on (heliospheric DA, whole atmosphere modelling)

• Progress is also being held back by lack of sufficient observations

• WMO space weather team have provided observations requirements and analysed gaps

• Guide design for new operational L1 and L5 solar / heliosphere missions and new observations for the thermosphere.

• Greater publicity of WMO activities and interaction with other relevant groups (Smallsat researchers, CGMS, etc, etc) vital

• Maybe have an observations R2O workshop?

15

Conclusions