AIRBORNE FIELD MILL PROJECT KENNEDY SPACE CENTER
SYNTHESIS FOR FEB 10, 2001 - ABFM
The radar data for this day is the Jacksonville NEXRAD (KJAX).

Flight Summary
Case 1 (Times: 2250 - 2309)

Type of case	CuCg
Complexity	simple
Convection	isolated cell
Electric field   kV/m	Min Em_m = 0.013 Max Em_m = 15.413 Mean Em_m = 0.603
Microphysics   #/Liter	Max CON_FSSP = 47092.980 Mean CON_FSSP = 2977.234 Max Tot_con_1DC = 202.931 Mean Tot_con_1DC = 12.068 Max Tot_con_2DC = 245.949 Mean Tot_con_2DC = 14.958 Max 2DC_100_400 = 57.442 Mean 2DC_100_400 = 2.995 Max 2DC_400_1000 = 122.423 Mean 2DC_400_1000 = 7.997 Max 2DC_GT_1000 = 1.686 Mean 2DC_GT_1000 = 0.116
Location	(x,y) ~ (-230,180)
Storm Motion	7.9 m/s to the east, 1 m/s north gives 8 m/s NE
Brief Description	This was a small, isolated CuCg that became moderately electrified. It appeared shortly before the aircraft got there and dissipated just after the aircraft left.

Case 2 (Times: 2312 - 2345)

Type of case	very marginal thick cloud
Complexity	simple
Convection	weak, embedded mid-level as seen from the Citation
Electric field   kV/m	Min Em_m = 0.045 Max Em_m = 0.185 Mean Em_m = 0.082
Microphysics   #/Liter	Max CON_FSSP = 56392.805 Mean CON_FSSP = 5557.128 Max Tot_con_1DC = 0.250 Mean Tot_con_1DC = 0.007 Max Tot_con_2DC = 0.411 Mean Tot_con_2DC = 0.002 Max 2DC_100_400 = 0.074 Mean 2DC_100_400 = 0.000 Max 2DC_400_1000 = 0.106 Mean 2DC_400_1000 = 0.001 Max 2DC_GT_1000 = 0.016 Mean 2DC_GT_1000 = 0.000
Approx. Location	(x,y) ~ (-120,220)
Storm Motion	There is not enough reflectivity in the CAPPIs to determine the storm motion.
Brief Description	This was a borderline "thick cloud", that had very weak electric fields.

SYNTHESIS FOR FEB 10, 2001 - ABFM
Jim Dye
Dec. 12, 2003

[Not presented at a teleconference.]

CASE I
Flight notes indicate a first penetration into a CuCg at about 2253. This and a following penetration between 2256 and 2257 are shown in
MER Plot 2250-2300
and
CAPPI 2250-2256
Note the scattered returns at 6 and 7km to the NE of the A/C track. This is where it will fly for Case 2 below.
The MER plot shows radar top on this small cell at ~9km with base at ~ 3km (~+6 C). The A/C penetrations were at 6.2 km (~-15C).

A following pass at 2301 to 2302 shows Emag to 20 kV/m.
MER Plot 2300-2310
CAPPI 2301-2307

Note in the MER plots for both passes that the FSSP, 1D and 2D probes show that particles were present and that some particles >1 mm were measured by the 2D probe. Thus, the particle probes were functioning properly, an important result for Case II below.

Summary:
This small CuCg was just large enough to produce moderate electric fields. This case also shows that the microphysical and electric field instruments were working properly.

CASE II
After leaving the small CuCg we flew to an area to the ENE with layer clouds with some weak embedded convection as seen by small turrets extending above the scattered layers.

Review of CAPPIS before the A/C investigation show the presence of radar detectable layer clouds in this region from at least 1800 to 2200. Special CAPPI 2000 - 2006
At 2100 vertical cross sections show the cloud extended from ~5 to 9 km, so definitely would have been considered a thick cloud at that time.

But by 2300 much thinning of the cloud had occurred, leaving only a few scattered echoes shown in the 2313-2319 CAPPI.
Special CAPPI 2313-2319

My Flight Notes state
"2317 -- Trying to get clearance to climb; in and out of cld layered, but potentially meets thick cld rule; still at 20 kft; -15C."
The MER plot for 2310 to 2320
MER 2310-2320
shows the FSSP to be detecting particles (probably supercooled cloud droplets) and even the 1D occasionally shows the presence of particles, e.g. 231800 to 231830. At 231800 when the 1D probe is detecting particles, the MER plot shows a 2 pixel radar return of 0 to 5 dBZ from 6 to 8km in a place where 1D probe is also detecting particles. Special CAPPIs produced for 5, 6 and 7 km to investigate the vertical extent of the layer show that during the period of this investigation (2312 to 2345) there were a few, highly scattered radar returns at 5, 6 and 7km. The A/C was at 6.2 km.

A specially produced vertical section hand selected to show the largest vertical extent of the radar return near the A/C is shown below. Special Vert. Section 2319-2325 at Y=216
The volume scan 6 minutes later near that same location shows
Special Vert. Section 2325-2331 at Y=215

So there was some continuity of the return, but from the radar perspective it seems more like a small cell rather than an extensive layer. And with this little return it's hard to know if it meets the 4500 feet criteria for a thick cloud.
The weak scattered returns persist during the investigation and afterwards and are consistent with the measurements from the FSSP and the flight notes that indicate the A/C was flying in and out of weak cloud.

Excerpts from flight notes:
"2321 -- Cleared to 23 kft, broke above clouds at ~21 kft."
"~2325 -- Photo to S of turret above our alt. at 23 kft."
"233520 -- start spiral at 18 kft, ...."
"in cld at 19.5, out at 21 k, back in at 22 k."
"At 23.2, clds to SW just a little above us maybe to 23.5"

Summary:
From the above flight notes and the scattered radar returns, it appears that this cloud was on the edge of what the criteria for a thick cloud requires. However, the radar returns are too scattered to be definitive.
In any case it is at the extreme lower end of what would be considered a thick cloud for LLCC purposes.
It is worth noting though that the electric fields were very weak. The strongest Emag observed was ~ 200 V/m.