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Data Product Descriptions

hmi.rdMAI_fd15

Data Series Class: Local Helioseismology Activity Indices
Creating Module: maicalc
Input Data: hmi.M_45s

Data Processing Status

The series only began to be populated as part of the Ring-Diagrams pipeline beginning with CR 2195 (Sep 2017). It was retrospectively populated working backward in time from CR 2195. Records for CR 2096–2194 were fully populated as of 26 March 2018.

Note that in the filling of records for times not populated as part of the Ring-Diagrams pipeline, the minimum data coverage criterion of 70% is not applied. Only intervals for which no suitable magnetograms exist will be skipped. There is only one such interval to date for this series: 2180:315.

Values of the keyword CRLN_OBS describing the Carrington longitude of the central meridian at the time of observation in the input magnetograms hmi.M_45s (and the other corresponding observables, as well as those in the 720-sec cadence series) were erroneous, consistently too high by 0.081894, corresponding to a time offset of 1 AU/c and a plate location offset of about 3 pixels. The correction for new data is pending as of 8 Dec 2021. This may introduce a detectable error in the tracking rate. Processing of uncorrected data corrects for this error beginning with maicalc v 2.3.

Versions of creating module used to produce records in the data series:

Note that records created with Version 2.0 originally lacked valid values for several keywords: Samples, MeanMu, MeanPA, and COMMENT. However, values for the first three of these have been subsequently set by an independent module using the same algorithm, data, and parameters.

Because the MAI is a linear fit at the target time of the several means of |Bz| at the sample times, it can potentially be negative, especially if all available values are on one side of the target time. This “feature” was addressed in Version 2.1, replacing a negative extrapolated or interpolated value at the target time with a simple mean. There are no records in this series with negative values of MAI.

The following records have been subsequently reprocessed and exist in multiple versions in the DRMS database:

All data records originally produced with versions 2.0–2.2 of maicalc have been mirrored to the data series hmi.rdMAI_fd15_reproc. Most of those that were subsequently reprocessed with version 2.3 or higher have been removed from this series and exist only in the mirrored series.

For current processing status, see the Ring-Diagram Status page.

Data Notes

The constant keywords in the JSOC Series Definition assure that the reference space-time data cubes are colocated with and mapped at the same scale as those for data based on those in hmi.rdVtrack_fd15, although mapped with a Lambert Azimuthal Equivalent projection rather than Postel's (they are nearly identical at this size), and apodized in space and time the same way as the power spectra in hmi.rdVpspec_fd15. Also, the “noise” cutoff value must be 50 gauss.

In producing these data, one in 64 of the input magnetograms are sampled, for a nominal cadence of once every 48 minutes. Alternate nearby magnetograms (out to a distance of 24 min) may be used if those at the nominal target times are missing or unacceptable. The list of magnetograms used is in the key HISTORY.

The fixed arguments to maicalc used in populating this series are:

During the time range CR 2096-2200 (May 2010 – Feb 2018) the mean value of MAI in 710,831 tracked regions was 3.040 (median 0.931), with a maximum value of 330.41 for region 2156:240 247.5-15.0 and a minimum value of 0.035 for region 2154:060 040.0-67.5. The ten tracked regions with the largest MAI, all clearly associated with the disc passage of NOAA AR 12192, were:

  1. 2156:240 247.5–15.0 — 330.41
  2. 2156:225 247.5–15.0 — 326.65
  3. 2156:255 247.5–15.0 — 326.28
  4. 2156:210 247.5–15.0 — 306.98
  5. 2156:270 247.5–15.0 — 293.23
  6. 2156:195 247.5–15.0 — 272.00
  7. 2156:180 247.5–15.0 — 250.17
  8. 2156:285 247.5–15.0 — 247.31
  9. 2156:210 240.0–15.0 — 244.30
  10. 2156:225 240.0–15.0 — 242.97
The ten time samples with the largest values of MAI averaged over all regions were:
  1. 2156:225 (2014.10.25_05:34) — 9.267
  2. 2156:240 (2014.10.24_02:16) — 9.200
  3. 2156:255 (2014.10.22_22:58) — 9.160
  4. 2156:210 (2014.10.26_08:52) — 8.741
  5. 2158:225 (2014.12.18_20:30) — 8.701
  6. 2152:255 (2014.07.05_23:05) — 8.570
  7. 2156:270 (2014.10.21_19:41) — 8.509
  8. 2152:240 (2014.07.07_02:17) — 8.423
  9. 2158:240 (2014.12.17_17:11) — 8.328
  10. 2152:270 (2014.07.04_19:53) — 8.286

JSOC Series Definition

#=====Global Series Information=====
Seriesname:	hmi.rdMAI_fd15
Description:	"Magnetic Activity Index series for 15-deg tiles"
Author:		"Rick Bogart"
PrimeKeys:	CarrRot, CMLon, LonHG, LatHG, LonCM
DBIndex:	CarrRot, CMLon, LonHG, LatHG, LonCM
Version:	2.1

#=====Links=====

# ===== Keyword list ===== #
# Format:
#   Keyword: <name>, link, <linkname>, <target keyword name>, <comment>
# or
#   Keyword: <name>, <datatype>, {constant | variable}, {record | segment}, 
#            <default value>, <format>, <unit>, <comment>
       
Keyword: CarrRot, int,    variable, record, -1,  %d,     N/A, "Carrington rotation at MidTime"
Keyword: CMLon,   float,  slot,     record, 360, %03.0f, deg, "Longitude of central meridian at MidTime"
Keyword: LonHG,	  float,  slot,     record, NaN, %05.1f, deg, "Longitude of tracked region center"
Keyword: LatHG,	  float,  slot,     record, NaN, %+05.1f, deg, "Latitude of tracked region center"
Keyword: LonCM,   float,  slot,     record, NaN, %+05.1f,  deg, "CM (Stonyhurst) Longitude of region center at MidTime"
Keyword: MAI,     float,  variable, record, NaN, %.3f, G, "Magnetic Activity Index"
Keyword: dMAIdt,  float,  variable, record, NaN, %.3f, uG/s, "Rate of change of Magnetic Activity Index"
Keyword: MeanBigBz,float, variable, record, NaN, %.3f, G, "Signed mean of strong field"
Keyword: dMnBigBdt,float, variable, record, NaN, %.3f, uG/s, "Rate of change of signed strong field mean"
Keyword: BigBArea, float, variable, record, NaN, %.4f, N/A, "Fraction of area covered by contributing field"
Keyword: T_OBS,   time,   variable, record, JD_0, 0, TAI, "Effective sample-weighted observation time"
Keyword: BMin,    float,  variable, record, NaN, %.0f, G, "Minimum contributing B  value"
Keyword: LonBMin, float,  variable, record, NaN, %06.2f, deg, "Longitude of minimum contributing B  value"
Keyword: LatBMin, float,  variable, record, NaN, %+06.2f, deg, "Latitude of minimum contributing B  value"
Keyword: t_BMin,  time,   variable, record, JD_0, -1, TAI, "Time of minimum contributing B  value"
Keyword: BMax,    float,  variable, record, NaN, %.0f, G, "Maximum contributing B  value"
Keyword: LonBMax, float,  variable, record, NaN, %06.2f, deg, "Longitude of maximum contributing B  value"
Keyword: LatBMax, float,  variable, record, NaN, %+06.2f, deg, "Latitude of maximum contributing B  value"
Keyword: t_BMax,  time,   variable, record, JD_0, -1, TAI, "Time of maximum contributing B  value"
Keyword: RMax,	  float,  variable, record, NaN, %06.4f, N/A, "Maximum magram r/R location in apodization circle"
Keyword: MeanMu,  float,  variable, record, NaN, %.4f, N/A, "Mean center-to-limb parameter"
Keyword: MeanPA,  float,  variable, record, NaN, %.1f, deg, "Mean position angle on image"
Keyword: BadPix,  float,  variable, record, NaN, %.6f, N/A, "Maggram pixel fraction in apodization circle offlimb or despiked"
Keyword: Samples, short,  variable, record, -1, %d, N/A, "Number of contributing time samples"
Keyword: Module,  string, variable, record, unknown, %s, N/A, "Creation module"
Keyword: Source,  string, variable, record, unknown, %s, N/A, "Input data source"
Keyword: Created, time,   variable, record, JD_0, -1, Z, "Record creation time"
Keyword: BLD_VERS,string, variable, record, unknown, %s, N/A, "JSOC library build"
Keyword: HISTORY, string, variable, record, "", %s, N/A, "Record creation/modification history"
Keyword: COMMENT, string, variable, record, "", %s, N/A, ""
# remainder are constant for series
Keyword: MapProj, string, constant, record, LambertAzimuthal, %s, N/A, "Map projection"
Keyword: MapScale,float,  constant, record, 0.040, %.3f, deg/pixel, "Map scale"
Keyword: Size,    float,  constant, record, 15.36, %.2f, deg, "Diameter of region (nominal)"
Keyword: Apode_t, float,  constant, record, 0.96875, %.5f, NA, "Temporal apodization edge"
Keyword: Apod_Min,float,  constant, record, 0.9765625, %.7f, NA, "Inner spatial apodization edge"
Keyword: Apod_Max,float,  constant, record, 1.000, %.4f, NA, "Outer spatial apodization edge"
Keyword: BFloor,  float,  constant, record, 50.0, %.2f, G, "Cutoff for rejection of weak field"
# prime key slotting info (hidden)
Keyword: CMLon_base, float, constant, record, 360, %.0f, deg, "CMLon index base"
Keyword: CMLon_step, float, constant, record, -15, %.0f, deg, "CMLon index step"
Keyword: LonHG_base, float, constant, record, 0.0, %.1f, deg, "LonHG index base"
Keyword: LonHG_step, float, constant, record, 2.5, %.1f, deg, "LonHG index step"
Keyword: LatHG_base, float, constant, record, 90.0, %.1f, deg, "LatHG index base"
Keyword: LatHG_step, float, constant, record, -7.5, %.1f, deg, "LatHG index step"
Keyword: LonCM_base, float, constant, record, 0.0, %.1f, deg, "LonCM index base"
Keyword: LonCM_step, float, constant, record, 2.5, %.1f, deg, "LonCM index step"

#=====Segments=====
#
# none
#


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