Space Weather Nowcast of Atmospheric Ionizing Radiation for Aviation Safety - PowerPoint PPT Presentation

Loading...

PPT – Space Weather Nowcast of Atmospheric Ionizing Radiation for Aviation Safety PowerPoint presentation | free to download - id: 8a90e-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Space Weather Nowcast of Atmospheric Ionizing Radiation for Aviation Safety

Description:

Kent Tobiska (Co-I), Space Environment Technologies, Inc, ... NASA Applied Science Weather Program Review. Boulder, Colorado, November 19, 2008. Outline ... – PowerPoint PPT presentation

Number of Views:36
Avg rating:3.0/5.0
Slides: 27
Provided by: scienceL
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Space Weather Nowcast of Atmospheric Ionizing Radiation for Aviation Safety


1
Space Weather Nowcast of Atmospheric Ionizing
Radiation for Aviation Safety
  • NAIRAS Team
  • Chris Mertens (PI)
  • Kent Tobiska (Co-I), Space Environment
    Technologies, Inc, Pacific Palisades, CA.
  • Brian Kress (Co-I), Dartmouth College, Hanover,
    NH.
  • Stan Solomon (Co-I), NCAR/HAO, Boulder, CO.
  • Mike Wiltberger (Co-I), NCAR/HAO, CO.
  • Joe Kunches (Collaborator), NOAA/Space
    Environment Center, Boulder, CO.
  • Barbara Grajewski (Collaborator), CDC/NIOSH,
    Cincinnati, OH
  • Steve Blattnig, (Collaborator), LaRC RT/Space
    Radiation Group
  • John Norbury (Collaborator), LaRC RT/Space
    Radiation Group
  • Tony Slaba (Collaborator), LaRC RT/Space
    Radiation Group

NASA Applied Science Weather Program
Review Boulder, Colorado, November 19, 2008
2
Outline
  • Project Overview
  • Summary of Milestones
  • Discussion of Milestones
  • Publications
  • Summary

3
Nowcast of Atmospheric Ionizing Radiation for
Aviation Safety (NAIRAS)
  • Earth System Models
  • Radiation Dose Rates
  • AIR (parametric)
  • HZETRN (physics-based)
  • Near-Earth Space Environment
  • Badhwar/ONeill GCR Model
  • Empirical Cutoff Rigidity
  • ( IGRFT05)
  • Physics-based Cutoff Rigidity
  • (LFM/CMITSEP-trajectory)

Value Benefits to Society Improvements in the
decision-making, decisions, and
actions First-ever, data-driven, real-time
prediction of biologically harmful radiation
exposure levels at commercial airline
altitudes Quantitative and qualitative benefits
from the improved decisions Comprehensive
database of radiation dose rates to formulate
recommended annual and career limits to ionizing
radiation exposure Comprehensive database of
radiation dose rates for airlines to assess
cost/risk of polar routes Real-time prediction of
radiation exposure levels to enable optimal
balance between airline cost and air traveler
health risk during solar storm (SEP)
events Improve understanding of biological
effects of atmospheric ionizing radiation on
aircrew and passengers through collaboration of
epidemiological studies by NIOSH
Predictions/Forecasts
Decision Support Systems, Assessments, Management
Actions NAIRAS decision support tool for
NOAA/SEC space weather forecasts, warnings, and
advisories NAIRAS available at NOAA/ADD
experimental aviation-related weather forecasts,
observations, and analysis Specific analyses to
support the decision making Predict real-time
radiation exposure at commercial airline
altitudes (includes background GCR and SEP
events) Provide accumulated radiation exposures
for representative set of domestic,
international, and polar routes Specific
Decisions / Actions Limit aircrew flight hours
to within recommended annual and career
limits Alter route and/or altitude during SEP
events

Ionizing Radiation Nowcast 3-D Dose
Equivalent 3-D Differential Flux NAIRAS
Distributed Network System High-Performance
Computer Systems Server Interface Operational
and Archival Databases Differential Particle
Flux HZE Particles (Z5-26) Light-Ions
(Z1-4) Neutrons Pions and Muons Electromagnetic
Cascasde Particles

Earth Observations Near-Earth Space
Environment NASA/ACE NASA/HEAO-3 NOAA/GOES Assimi
lated Atmospheric Atmospheric Depth
(NCAR/NCEP) Ground-Based Neutron Count Monitors
Observations, Parameters Products
4
Physics-Based Atmospheric Ionizing Radiation
Dosimetry
Cutoff Rigidity (IGRF)
NOAA GOES Data
Real-time Neutron Monitor Data (e.g., IZMIRAN
and LOMICKY)
Fit to Climax NMC
Spectral Fitting
Magnetospheric Magnetic Field (e.g.,
T05) Effects on Cutoff Rigidity
NASA/ACE Solar Wind and IMF Data
BadhwarONeill GCR Model
HZETRN Dosimetry
Atmospheric Density
Atmospheric Dose and Dose Equivalent
NCAR/NCEP Reanalysis
5
Important Milestones Achieved(1)
  • NAIRAS operational distributed network system
  • System designed and implementation underway
  • Model I/O requirements and sources defined
  • Redundancy established for all input data
    products
  • Operational HZETRN
  • Automated canonical radiation flux and dose rate
    calculations performed on 2-D (rigidity,
    atmospheric depth) grid
  • Preliminary coupling to SEP fluence spectral fit
    model, cutoff rigidity model, and NCAR/NCEP
    Reanalysis Data (air temperature and geopotential
    height)
  • Working on including directional anisotropy in
    rigidity, flux, and subsequent dose predictions
  • Directionally-coupled low-energy neutron
    transport
  • Tony Slabas PhD thesis and post-doc work (ODU)
  • Validated against Monte Carlo Codes (FLUKA and
    HET-HEADS) for September 1989 SEP event
  • Now Implemented in NAIRAS
  • Factor 4 greater doses rates in polar cap region

6
Important Milestones Achieved(2)
  • SEP proton and alpha fluence spectral fitting to
    ACE/GOES
  • Version 1 operational algorithm implemented with
    preliminary testing
  • Funded two students through the Langley Aerospace
    Research Summer Scholars (LARSS) Program to
    contribute to this work
  • Analysis of Halloween 2003 SEP events
  • Storm-time geomagnetic effects on cutoff
    rigidities critical
  • Magnetospheric effects reduce mid- to
    high-latitude cutoffs by as much as a 1 GV.
  • Increase total dose by as much as a factor of 4
  • ICRP prenatal exposure exceeded during typical
    commercial polar routes

7
NAIRAS Operational Distributed Network
System Next Slide
8
NAIRAS Operational Distributed Network System
9
NAIRAS Models and I/O Definitions Next Two Slides
10
(No Transcript)
11
(No Transcript)
12
SEP Proton and Alpha Fluence Spectral
Fitting Next Five Slides
13
(No Transcript)
14
SEP Event 3 From Previous Slide Event-Averaged
Analysis for Event 3 in Next Section
15
HZETRN SEP Atmospheric Transport
  • Incident SEP spectra non-linear least-squares
    spectral fit to NOAA/GOES and NASA/ACE
  • Double power-law spectrum Mewaldt, 2003

16
(No Transcript)
17
(No Transcript)
18
Analysis of Halloween 2003 SEP Event Next Six
Slides
19
High-latitude routes can exceed ICRP prenatal
limit (1 mSv)
ICRP annual limit (20 mSv)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
Summary of Total Dose Equivalent and Influence of
Geomagnetic Effects
Neglect geomag effects underestimates dose by
factor 4
Flight Path Dose Eq. T05S (mSv) Dose Eq. T05Q (mSv) Dose Eq. IGRF (mSv) Dose Ratio T05S/IGRF Dose Ratio T05S/T05Q Dose Ratio T05Q/IGRF
JFK-LHR .371 0.128 0.092 4.03 2.90 1.39
ORD-ARN .840 .543 .376 2.23 1.55 1.44
ORD-PEK 1.138 .931 .856 1.33 1.22 1.09
T05S Tsyganenko (T05) Storm Field T05Q
Tsyganenko (T05) Quiet Field
ICRP prenatal limit (1 mSv) exceeded
IGRF underestimates geomag quiet condition by
40
25
Publications
  • Journal of Space Weather (January, 2009)
  • Geomagnetic effects on high-latitude radiation
    exposure during a Halloween 2003 solar energetic
    particleevent (Mertens et al.)
  • Journal of Space Weather (January 2009)
  • Variations in geomagnetic shielding of energetic
    solar ions during severe geomagnetic storms
    (Kress et al.)
  • AIAA Paper (AIAA 2008-463, January, 2008)
  • Influence of space weather aircraft ionizing
    radiation exposure (Mertens et al.)

26
Summary
  • Operational distributed network system
    development on schedule
  • Operational HZETRN development on schedule
  • Directionally-coupled, low-energy neutron
    transport with coupling to light-ion transport
    implemented and tested in NAIRAS.
  • SEP proton and alpha fluence spectral fitting
    model developed. Initial testing in progress.
  • Atmospheric radiation exposure during Halloween
    2003 SEP event exceeded ICRP prenatal exposure
    limit (1 mSv) for typical polar route. Some
    high-latitude routes reached 85 of ICRP
    prenatal limit.
  • Neglecting time-dependent geomagnetic storm
    influences on cutoff rigidity during SEP events
    significantly underestimates radiation dose from
    30 to over a factor of 4
  • IGRF field can result in underestimation of
    high-latitude radiation dose by 40 for SEP
    events without accompanying geomagnetic storm
  • Two peer-reviewed journal articles in progress.
    One AIAA paper published.
About PowerShow.com