# Presentation: 183792

## Space Climatology Models in the Context of Space Weather

**Workshop on New Standard Radiation Belt and Space**
**   ****Plasma Models for Spacecraft Engineering**
**5-8 Oct 04**

- G. P. Ginet
- Air Force Research Laboratory

## Why New Standard Radiation Belt and Plasma Models?

**Why New Standard Radiation Belt and Plasma Models?**

- New technologies & missions are increasingly susceptible to space environment hazards
- Better models are needed for smart system acquisition:
-  Broader energy range, both upper (> 100 MeV) and lower (< 1 MeV)
-  More detailed spectral & pitch angle resolution
-  Probability of threshold occurrence & duration for 10+ year missions
- Better models will reduce acquisition costs, improve capabilities and extend mission lifetimes
- Willing to wager that AP-8 and AE-8 are one of the top two most applied space weather model sets outside of the space physics science community
-  Improved models will have a large “impact on society” for LWS
- [Other model: ionosphere correction algorithm in single frequency GPS receivers]

## Radiation Levels of Concern

**Radiation Levels of Concern**

**20**

**40**

**60**

**80**

**100**

**Soft (<40)**

**Tolerant (40-80)**

**Hard (>80)**

**SEU (LET)**
**[MeV/mg/cm2]**

**10****3**

**10****4**

**10****5**

**10****6**

**10****7**

**Soft (<20)**

**Tolerant w/ shielding (20-100)**

**Hard (>500)**

**Total Dose (rad)**

**Tolerant (100-500)**

**10****6**

**10****7**

**10****9**

**10****10**

**10****11**

**Soft (<20)**

**Tolerant (10****7****-10****9****)**

**Operate Through (>10****10****)**

**Dose Rate (rad/sec)**

**Hard**** (10****9****-10****10****)**

**0**

**40**

**80**

**120**

**160**

**Soft (<40)**

**Tolerant (40-120)**

**Hard (>120)**

**SEL (LET)**
**[MeV/mg/cm2]**

**10****-4**

**10****-6**

**10****-8**

**10****-10**

**10****-12**

**Soft (>10****-6****)**

**Tolerant w/EDAC  (10****-6****-10****-8****)**

**Hard (<10****-10****)**

**SEU (err/b-d)**

**Tolerant (10****-8****-10****-10****)**

**10****11**

**10****12**

**10****13**

**10****14**

**10****15**

**Soft (<10****12****)**

**Tolerant (10****12****-10****14****)**

**Hard (>10****14****)**

**Neutron (n/cm****2****)**

**From S. Tyson, AFRL/VSS**

**Note: surface & deep charging not included**

## Radiation EnvironmentsDSX MEO Orbit Study

**Orbit 1 **

**Orbit 2**

**Orbit 3**

**Orbit 4**

## Radiation EnvironmentsRadiation Dose – 1 year

**rads(Si)/yr**

**rads(Si)/yr**

**Radiation Environments****Radiation Dose – 1 year**

**From CRRESRAD model**

**Quiet**

**Active**

**10****5**

**10****4**

**10****3**

**10****5**

**10****2**

**10****1**

**10****6**

**10****4**

**10****3**

**10****2**

## Spacecraft DesignThe Problem

- For MEO orbit (L=2.2), #years to reach 100 kRad:
- Quiet conditions (NASA AP8, AE8) :  88 yrs
- Active conditions (CRRES active) : 1.1 yrs
- AE8 & AP8 under estimate the dose for 0.23’’ shielding

- Model Dose rates behind 0.23’’ Al
- (>2.5 MeV e ; >135 MeV p)

**L (R****E****)**

**DOSE (Rads/s)**

- HEO dose measurements show that current radiation models (AE8 & AP8) over estimate the dose for thinner shielding

**J. Fennell, SEEWG 2003 **

**Spacecraft Design****The Problem**

**Example: Highly Elliptic Orbit (HEO) **

**Example: Medium-Earth Orbit (MEO) **

## Space Environment ModelsDynamic Electron Environment

**Electrons > 0.55 MeV****   **
**(protons > 40 MeV)**

**Electrons > 1.2 MeV**
** ****(protons > 78 MeV)**** **

**Electrons > 3.5 MeV**
** ****(protons > 86 MeV)**** **

**Space Environment Models****Dynamic Electron Environment**

**L-shell**

- “Halloween Storm” analysis:
- “Empty” slot region fills up with energetic electrons for > 20 days
- Anomalously long lifetime observed for >1.2 MeV electron channel

**Existing models inadequate for satellite design (climatology) or situational awareness (nowcast-forecast)**

## Space Environment ModelsSevere Electron Environments

**Electrons > 0.55 MeV****   **
**(protons > 40 MeV)**

**L-shell**

**Electrons > 1.2 MeV**
** ****(protons > 78 MeV)**** **

**Electrons > 3.5 MeV**
** ****(protons > 86 MeV)**** **

**Space Environment Models****Severe Electron Environments**

- July 2004 Storm analysis:
- Lower inner belt region fills up with energetic electrons for > 35 days
- Extremely hard electron spectrum
-  By far the worst seen in 4+ years of CEASE/TSX5
-  Set record for GOES > 2 MeV daily ave

**Electrons > 7 MeV****   **
**(protons 21-36 MeV)**

## New Standard ModelsThe User “Mandate”

- SEEWG Workshop 2002: “Space Environment Effects on Large Imaging Systems”
- Recommendations:
**Create technical committee to develop updated radiation environment models**
**International group needed**
**U.S. national group could be under SEEWG Rad. Envir. subcommittee**
- Support improved data and modeling for energetic protons and electrons for 1<L<3.5
- Support collection of data for low energy plasmas between LEO and GEO (1<L<6)
- Fly radiation measurement instruments on as many operational satellites as possible
- Build dynamic “outer zone” (MEO orbit regime) electron model
- Internal & surface charging specifications are needed
- SEEWG Workshop 2003 on “Space Environment Effects on Transformational Communications Architectures” provided similar recommendations
- STA charged SEEWG to go forth and do it

-  Space Technology Alliance (STA) - DoD, NASA, DoE, NOAA
-  STA subgroup: Space Environment Effects Working Group (SEEWG)

## Technical Challenges

- “Clean up” and cross-calibrate a diverse data set
-  Remove contamination by high energies, other species, secondaries, etc.
-  Quantify often sparse energy and pitch angle resolution
- Assimilate diverse data sets into a coherent global picture
-  Back-out “best guess” local energy & pitch angle spectra
-  Map set of local measurements into global distribution
- Determine most useful output for design community
-  Map orbit space into space physics domains
-  Estimate probability of occurrence and duration for multiple time scales
-  Determine activity fidelity and drivers, e.g. SSN, Kp, Dst, F10.7
- Design an easily extensible model
- Validate with ground truth data not in the model

## Political Challenges

- ALL concerned parties need to accept new standard
-  Satellite builders: IEEE, AIAA, etc.
-  Satellite users: NASA, ESA, DoD, Direct TV, Virgin Galactic, etc.
-  Approver organizations: ISO, ANSI,COSPAR, STA, etc.
-  Model developers: AGU, NSF, National Labs, NASA, ESA
- Acceptance can be pursued in parallel to model development
-  But will require proof that new standard is better
- Need international data and model exchange agreements
- Funding has to be pursued
-  Well defined, high-priority requirements
-  Coherent, executable plan with deliverables
-  Who pays?
-  Satellite users and builders
-  Research organizations

**Builders, users, approvers and developers all need to be on-board **

## Climatology Role Space Weather

- High priority SWx product
- Building new standard models requires science
-  Detector characterization
-  Optimal spectral and pitch-angle characterization
-  Assimilation into global picture
- Climatology provides initial conditions and defaults for nowcast and forecast models

## Where do we go from Here?

- Continue New Standard Radiation Belt group convened this week
-  Coordinate developers and resources currently engaged
-  Address time-critical program and technical issues
- Develop proposal for development of new standard models
-  Identify costs, schedule, milestones, products
-  First GEO, LEO then MEO
-  Draft end-to-end model structure with example
- Decide on ultimate COSPAR oversight role and delineate responsibilities
- Engage NASA and DoD international affairs people to develop data and model exchange agreements
- Develop user, builder, approver and developer briefings and hit the road

## Conclusions

**Conclusions**

**10-100 MeV **
**protons**

**1-10 MeV **
**electrons**

**LEO**

**MEO**

**GEO**

**HEO**

**Thanks to Janet, Don, Bern and Eamon for putting together a great workshop! **