InFO 20007: International Civil Aviation Organization (ICAO) Space Weather - Centers and ICAO Space Weather Advisories.

Distributed by: Air Transportation Division

http://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/info An InFO contains valuable information for operators that should help them meet certain administrative, regulatory, or operational requirements with relatively low urgency or impact on safety. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.

Subject: International Civil Aviation Organization (ICAO) Space Weather - Centers and ICAO Space Weather Advisories.

Purpose: This InFO serves to provide information on the new provision of ICAO Space Weather Centers and Space Weather Advisories.

Background: Solar activity and monitoring has matured. Accordingly, the ICAO Meteorology Panel recommends using a global monitoring program. This program consists of the following three global space weather service providers:

Discussion: A space weather advisory is issued whenever space weather conditions exceed pre-defined ICAO thresholds for both moderate impacts (MOD) and severe impacts (SEV) as given in the table below. The space weather advisory is neither a significant meteorological (SIGMET) product nor a product that is equivalent to a SIGMET. The space weather advisory is not a replacement for SWPC’s other products or the NOAA Space Weather Scales, which will continue to be provided by the SWPC.

InFOInformation for Operators

U.S. Department

of Transportation

Federal Aviation

Administration

InFO 20007

DATE: 10/23/20

Flight Standards Service

Washington, DC

Distributed by: Air Transportation Division

Moderate impact radiation advisories will only be issued when the MOD threshold is reached between FL250 and FL460. SEV radiation advisories will be issued when the SEV threshold is reached at any FL above FL250. For context, the background effective dose rate at FL370 at very high latitudes is approximately 8 micro-Sieverts/hour. These rates decrease progressively toward the equatorial regions to values approximately one quarter of what is observed at very high latitudes. Severe impact radiation is a rare event, as only a few short-lived events occur during an 11-year solar cycle. Effect Sub-effect Parameter used Thresholds Impact within advisory area MOD SEV MOD SEV

GNSS Amplitude Scintillation S4 (dimensionless) 0.5 0.8

Possible

degraded service

Possible unreliable service

GNSS Phase Scintillation Sigma-phi (radians) 0.4 0.7

GNSS Vertical Total Electron

Content (TEC) TEC units 125 175

RADIATION Effective dose rate (micro-

Sieverts/hour) 30 80 Possible increased dose rates above normal levels.

HF COM Auroral Absorption (AA) Kp index 8 9

Possible

degraded service

Possible unreliable service

HF COM Polar Cap Absorption

(PCA) dB from 30MHz riometer data 2 5

HF COM Shortwave Fadeout

(SWF)

Solar X-rays (0.0-0.8 nm) (W-m-

2)

1x10-4

(X1)

1x10-3

(X10)

HF COM Post-Storm Depression Maximum usable frequency

(MUF) 30% 50%

SATCOM No threshold has been set for this effect

Possible degraded service

Possible unreliable service The space weather advisory provides information regarding an observed or expected occurrence and location of a space weather effect and the forecast of the effect at 6-, 12-, 18- and 24-hour intervals. The advisory depicts the affected region in one of three ways:

Distributed by: Air Transportation Division

Latitude bands used in space weather advisories

Title of the latitude bands Ranges of the

Latitude bands

High latitudes northern hemisphere (HNH) N90 to N60

Middle latitudes northern hemisphere (MNH) N60 to N30

Equatorial latitudes northern hemisphere (EQN) N30 to equator

Equatorial latitudes southern hemisphere (EQS) Equator to S30

Middle latitudes southern hemisphere (MSH) S30 to S60

High latitudes southern hemisphere (HSH) S60 to S90

The horizontal, vertical and temporal resolutions of the advisory are very coarse. The use of 30-degree latitude bands, 15-degree longitude increments, 3,000-foot vertical increments (for radiation), and 6-hour time intervals will, at times, result in over forecasting the affected airspace. In addition, while an entire latitude band might be forecast to have MOD or SEV space weather, the effect, at times, does not cover the entire width of the band or might be intermittent or temporary. Users may refer to the remarks section of the advisory for additional information.

Users can also go to the center’s website where a graphical depiction of the space weather event may be provided along with additional information. Format of the space weather advisory:

Format Explanation Examples

Communication

header

Product’s coded identification for the issuing centers. KWNP is SWPC,

LFPW and YMMC are ACFJ, and EFKL is PECASUS.

FNXX01 KWNP

FNXX01 LFPW

FNXX01 YMMC

FNXX01 EFKL

SWX ADVISORY Space weather (SWX) advisory SWX ADVISORY

STATUS: Status indicator (optional) for Test or

Exercise

TEST

EXER

DTG: Date and time of origin, in

YYYYMMDD/HHMMZ 20190418/0100Z

SWXC:

Name of the Space Weather Advisory

Center (SWXC)

ACFJ

PECASUS

SWPC

ADVISORY NR: Advisory number (NR) 2019/9

NR RPLC: Advisory number being replaced by this

advisory (optional) 2019/8

SWX EFFECT: Space weather effect HF COM MOD

Distributed by: Air Transportation Division

Format Explanation Examples

HF COM SEV

SATCOM MOD

SATCOM SEV

GNSS MOD

GNSS SEV

RADIATION MOD

RADIATION SEV

OBS (or FCST) SWX:

Observed (OBS) or expected (FCST)

space weather effect date/time, location and altitudes (altitudes are only used in the radiation advisory).

18/0100Z EQN W18000-W12000

18/0100Z HNH HSH E180-W180 ABV FL370

18/0100Z DAYLIGHT SIDE

18/0100Z NO SWX EXP

FCST SWX +6 HR: 6-hour forecast. Date/time, location and

altitudes. Same as above

FCST SWX +12 HR: 12-hour forecast. Date/time, location and altitudes. Same as above

FCST SWX +18 HR: 18-hour forecast. Date/time, location and altitudes. Same as above

FCST SWX +24 HR: 24-hour forecast. Date/time, location and altitudes. Same as above

RMK: Remarks (RMK) Additional information

NXT ADVISORY: Date/time when the next (NXT) scheduled advisory will be issued 2010418/0700Z

Example. Space weather advisory – GNSS Note: GNSS is the acronym for Global Navigation Satellite System, which is the term for all the world’s navigation satellites, which includes the US’s Global Position Satellites (GPS).

FNXX01 KWNP 020100

SWX ADVISORY

DTG: 20190502/0100Z

SWXC: SWPC

ADVISORY NR: 2019/59

NR RPLC: 2019/58

SWX EFFECT: GNSS MOD

OBS SWX: 02/0100Z HNH HSH E18000-W18000

FCST SWX + 6 HR: 02/0700Z HNH HSH E18000-W18000

FCST SWX + 12 HR: 02/1300Z HNH HSH E18000-W18000

FCST SWX + 18 HR: 02/1900Z NO SWX EXP

FCST SWX + 24 HR: 03/0100Z NO SWX EXP

RMK: IONOSPHERIC STORM CONTINUES TO CAUSE LOSS-OF-LOCK

OF GNSS IN AURORA ZONE. THIS ACTIVITY IS

EXPECTED TO SUBSIDE IN THE FORECAST PERIOD

NXT ADVISORY: 20190502/0700Z=

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Example. Space weather advisory – RADIATION

FNXX01 EFKL 190300

SWX ADVISORY

DTG: 20190219/0300Z

SWXC: PECASUS

ADVISORY NR: 2019/20

SWX EFFECT: RADIATION MOD

OBS SWX: 19/0300Z HNH HSH E18000-W18000 ABV FL370

FCST SWX + 6 HR: 19/0900Z NO SWX EXP

FCST SWX + 12 HR: 19/1500Z NO SWX EXP

FCST SWX + 18 HR: 19/2100Z NO SWX EXP

FCST SWX + 24 HR: 20/0300Z NO SWX EXP

RMK: RADIATION AT AIRCRAFT ALTITUDES ELEVATED

BY SMALL ENHANCEMENT JUST ABOVE PRESCRIBED

THRESHHOLD. DURATION TO BE SHORT-LIVED

NXT ADVISORY: NO FURTHER ADVISORIES=

Example. Space weather advisory – HF COM

FNXX01 YMMC 020100

SWX ADVISORY

DTG: 20190202/0100Z

SWXC: ACFJ

ADVISORY NR: 2019/10

SWX EFFECT: HF COM MOD

OBS SWX: 02/0100Z DAYLIGHT SIDE

FCST SWX + 6 HR: 02/0700Z DAYLIGHT SIDE

FCST SWX + 12 HR: 02/1300Z DAYLIGHT SIDE

FCST SWX + 18 HR: 02/1900Z NO SWX EXP

FCST SWX + 24 HR: 03/0100Z NO SWX EXP

RMK: LOW END OF BAND HF COM DEGRADED

ON SUNLIT ROUTES. NEXT 12 HOURS

MOST POSSIBLE, DECLINING THEREAFTER.

NXT ADVISORY: 20190202/0700Z=

Changes to the space weather advisory content and format are possible. Additional information is available in ICAO Annex 3 – Meteorological Service for International Air Navigation and ICAO Doc 10100 – Manual on Space Weather Information in Support of International Air Navigation.

Recommended Action: Directors of Safety and Directors of Operations should be aware of the information in this InFO regarding access to the SWPC advisories. Consistent with existing regulations, certificate holders should keep manuals up-to-date concerning actions to take upon reviewing SWPC advisories.

Contact: Questions or comments regarding this InFO should be directed to the Air Transportation Division’s Air Carrier Operations Branch, at 202-267-8166.