AIRBORNE FIELD MILL PROJECT
KENNEDY SPACE CENTER

SYNTHESIS FOR JUNE 14, 2000 - ABFM

Flight Summary (Anvil Day)

Case 1 (Times: 2127 - 2158)
Type of case Anvil
Complexity Simple
Convection Not during this period.
Electric field
  kV/m 		Min Em_m = 0.090
Max Em_m = 0.688
Mean Em_m = 0.285
Microphysics
  #/Liter
Max CON_FSSP = 2888.813
Mean CON_FSSP = 576.374
Max Tot_con_1DC = 41.617
Mean Tot_con_1DC = 6.608
Max Tot_con_2DC = 49.490
Mean Tot_con_2DC = 7.422
Max 2DC_100_400 = 27.902
Mean 2DC_100_400 = 3.438
Max 2DC_400_1000 = 6.043
Mean 2DC_400_1000 = 0.930
Max 2DC_GT_1000 = 0.421
Mean 2DC_GT_1000 = 0.075
Location (x,y) ~ (-50,50)
Storm Motion 5 m/s to the west, 6 m/s to the north gives: 7.8 m/s NW

Brief Description

This is a decaying anvil. The generating convection was gone before the aircraft arrived.

Case 2 (Times: 2212 - 2409)
Type of case Anvil
Complexity Complex
Convection multiple cells
Electric field   kV/m Min Em_m = 0.135
Max Em_m = 43.089
Mean Em_m = 2.073
Microphysics
  #/Liter
Max CON_FSSP = 20913.869
Mean CON_FSSP = 1884.230
Max Tot_con_1DC = 433.223
Mean Tot_con_1DC = 25.450
Max Tot_con_2DC = 680.222
Mean Tot_con_2DC = 37.551
Max 2DC_100_400 = 261.497
Mean 2DC_100_400 = 17.130
Max 2DC_400_1000 = 36.088
Mean 2DC_400_1000 = 3.528
Max 2DC_GT_1000 = 1.979
Mean 2DC_GT_1000 = 0.280
Location (x,y) ~ (-18,-50)
Storm Motion 6.3 m/s to the west, 2.7 m/s to the north gives: 6.9 m/s NW

Brief Description

This case has multiple cells and multiple anvils. The anvil studied was a good case for studying the decay of an anvil.











SYNTHESIS FOR JUNE 14, 2000 - ABFM

Investigator: S. Lewis
[presented on Oct 3, 2002




Lightning Activity for Case 1 (compiled by Eric Defer)

Summary

Case 1
The aircraft flies in an along line pattern into an anvil NW of KSC.
(If you can loop through CAPPIs 1931 to 2159, and MER's 2110 to 2200 you can see the development of the anvil.) If you can't do the loops the single images that are representative of the system are:

CAPPI 2151.       mer_2150       lng_2130.       lng_2l40.       lng_2l40.       microphysics 2130.

The last lightning was at 2023, an hour before the aircraft arrived. The electric fields are low and the 2dc is about 10^1/liter.
CAPPI 2024.       lng_2023

Case 2
The aircraft flew to a storm SW of KSC at about 2210.

To watch the development of this system I would recommend looping between 2000 and the end of the radar processing. Since the aircraft didn't get there until 2212 we will start our discussion at that time. The relevant loops for the mer plots would be from 2210 until the end of the flight.

There were approximately 3 cells in this system and at least 2 anvils.
CAPPI 2212.       mer_2210       lng_2200.       lng_2210.       lng_2220.
Efields are weak (+/- 2kV/m) although there is lightning occurring in 2 of the 3 cells of this system.

The aircraft flies along-line and gets close to a core without producing strong efields.
CAPPI 2222.       mer_2220

The aircraft does a few legs through this anvil in an along-line pattern. At CAPPI 2241 you see a new anvil blowing off the northern most cell which is caught by the aircraft when it turns around. The microphysics show a little bit higher values but the fields are still weak. Notice that lightning is still occurring within the system.
CAPPI 2249.       mer_2250       lng_2230.       lng_2240.       lng_2250.

It is not clear which anvil the aircraft is flying through until about 2304 when it starts a series of cross-band legs near the northern core, and so we might assume we are now working the 2nd anvil.
CAPPI 2304.       mer_2300       lng_2300.       lng_2310.       lng_2320.

The subsequent cross-band legs are at various distances from the core. There appear stronger fields at 2331 which are not associated with any higher reflectivities, but there is still lightning in the area.
CAPPI 2328.       mer_2330       lng_2330.       lng_2340.       lng_2350.

But these fields are gone when the aircraft turns around for one last along-band leg at
CAPPI 2349.       mer_2350

So this case has several weak anvil cases. Case 1 was in decay and Case 2 still had lightning in the area.

The E vs Reflectivity plots don't really have any surprises. I would like to note that the scatter plot for "at the aircraft" has a single point at reflectivity at 5dBZ with E at 15kV/m, this point is elevated to 7 or 8 dBZ when box averages are taken. Just another reason not to believe single point-to-point comparisons.
Efield vs Reflectivity Scatter Plots Directory



End Summary

____________________________________________________________________

The flight for this day took off about 21:06 and covered 2 cases. The research legs were flown at 8.8 km (-32C).

CASE 1
This system was north of KSC. The motion of the system is NW at about 5 m/s. An anvil blows off to the SE and can be seen at:
CAPPI 1942.
During this time there is light lightning activity with more CG in the area of a core and LDAR sources appearing in or around the anvil.
lng_1900
The lightning activity picks up at
lng_1945 to lng_2025 .

At 2042 a new line of convection appears out in front of the anvil.
CAPPI 2042
This new band doesn't last long and shows only minor lightning activity at about
lng_2125       CAPPI 2124

The last lightning for the anvil was at:
lng_2023       CAPPI 2024

The aircraft enters this anvil at about

CAPPI 2124 and flies at the 7 km level. At this time the core that had created it was gone, and had been for about 45 minutes. Looking at the low-level convection
mer_2120
at 2125 and a the CAPPI (2124 link above) would suggest a fairly strong vertical sheer. At this time the total 2DC was 2x10^1; for particles > 1mm it was about 10^-1; and for fssp it was 10^3. Which are where they stay throughout the study.
2145

The mer plots and CAPPIs show elevated reflectivities with nothing below, just as you might expect for an anvil. The field mills on the aircraft don't come on until 2130 and the 2dc doesn't measure anything until 2142
mer_2140       CAPPI 2137
mer_2143       CAPPI 2145

The aircraft flew several legs back and forth through this anvil.
mer_2150       CAPPI 2153
Once the core is gone the anvil motion is eastward at 7 m/s.

There are no significantly measurable fields for the duration of this first case.

CASE 2
The aircraft reaches the 2nd Case about
CAPPI 2212       mer_2210
The CAPPI image appears to show an anvil blowing off to the SE. The mer plot suggests that is precipitating out. For the most part I would classify this case as decayed convection.

The aircraft flies some "along line" legs and then some "across line" legs.

It is not clear if this cell is where the lightning is occurring. I suspect that the lightning is associated with the cell a little to the south.
lng_2210.

This case is a littler messier than the first one. It starts off as a little band of convective cells. It is not a continuous band, but the cells are sometimes separated at the 4 km level. The band does, almost, look continuous at 7 and 10 km. At first this system doesn't move much, then at
CAPPI 2024
it starts moving to the NW. The first lightning for the second case appears to be at about
lng_2029.  ( first lng_2029.)

The aircraft is flying at 9km, which is below the anvil at 2214
mer_2210

This anvil is associated not with either of the two cells observed at the flight level (9 km), but with a smaller (shorter?) cell in between them that is visible at the 4km level.
CAPPI 2214
This cell is mostly gone by
CAPPI 2217 .

At the flight level the anvil
CAPPI 2220
starts to separate from the cell region.

At
mer_2220       ( +/- 5kV/m mer_2220)       CAPPI 2225
the aircraft flies directoy over the core/source for this anvil with only the slightest blip in the electric fields.

A second anvil starts at about
mer_2230       mer_5_2230
CAPPI 2230
associated with the northern most cell of the band. There is light electric field activity at this time. The last cloud to ground lightning flash for almost an hour occurs during this time.
lng_2230

When the aircraft re-enters the system at
mer_2240       CAPPI 2243
it is flying through the middle (vertically) of the anvil (z = 6-9km). Cloud top is about the same, so the cloud is thicker here. This anvil is probably being fed by the cell to the north. Both the 7 and 10km levels show there are more than one anvil. The lightning during this time is all IC.
lng_2240

By 2247 the aircraft is moving into this cell/anvil system and at 2251 when the cell depth goes from 2 to 15 km it must be in the cell region, there is a single blip on the field mills.
mer_2240       CAPPI 2251
lng_2250

Study of the CAPPIs and the mer plots shows that the aircraft was flying its legs between the southern anvil (2254-59)
mer_2254       CAPPI 2256
and then returns to the northern one (2300).
mer_2300       CAPPI 2304
The strong fields at 2306 occur when the aircraft flies right on the edge of the core right before IC lightning occurs there.
lng_2300
At this time the aircraft changes its flight pattern and does cross-band legs staying in the northern anvil while the southern anvil is dissipating.

The low level reflectivity at 2310 is the remains of the southern anvil.
mer_2310       CAPPI 2310
The relatively strong negative fields which occur at 2317 are while the aircraft is flying along the edge of a 25dBZ region that appears at the flight level (9km) but not at either of the lower horizontal plot levels.
CAPPI 2315

The last CG occurs at 2320.
lng_2320
CAPPI 2320

The anvil is above the flight level (9km) at 2324.
mer_2320       CAPPI 2320

At 2331 again there are strong fields (this time positive) with only a few pixels of 25dBZ at 10 km.
mer_2330       CAPPI 2333

The aircraft if flying north-south legs (or cross-band) so the fields at 2338 are most likely in the same place as the earlier ones, just later in time and hence further along in the decay of the anvil.
mer_2330       CAPPI 2336

The convection is much reduced and by
CAPPI 2347 the aircraft returns to an "along line" pattern.

The last radar image processed is
CAPPI 2354
The microphysics
2400 2415
and efield
2400
after midnight do not show much activity and the aircraft landed at about 2430.