| Type of case | debris | ||||||
| Complexity | simple | ||||||
| Convection | no convection | ||||||
| Electric field kV/m | Min Em_m = 0.046 Max Em_m = 10.764 Mean Em_m = 0.429 | ||||||
| Microphysics #/Liter |
| ||||||
| Location | (x,y) ~ (45,5) | ||||||
| Storm Motion | 4.4 m/s west, 1.7 m/s north gives 4.7 m/s NW | ||||||
Brief Description | decayed convection. Last lightning about 1719 in this cell. |
| Type of case | debris | ||||||
| Complexity | simple | ||||||
| Convection | single large cell | ||||||
| Electric field kV/m | Min Em_m = 0.089 Max Em_m = 50.338 Mean Em_m = 12.030 | ||||||
| Microphysics #/Liter |
| ||||||
| Location | (x,y) ~ (130,-100) | ||||||
| Storm Motion | 2.0 m/s west, 7.9 m/s north gives 8.1 m/s NW | ||||||
Brief Description | Althought the core is no longer at the position of the aircraft by looking at the animation it can be seen that the core was in this position. |
| Type of case | debris | ||||||
| Complexity | complex | ||||||
| Convection | line of convection | ||||||
| Electric field kV/m | Min Em_m = 0.141 Max Em_m = 1.100 Mean Em_m = 0.411 | ||||||
| Microphysics #/Liter |
| ||||||
| Location | (x,y) ~ (-50,50) | ||||||
| Storm Motion | 8.4 m/s west | ||||||
Brief Description | A reverse search from the aircraft position shows that the core was there in the recent past. |
| Type of case | debris | ||||||
| Complexity | moderate | ||||||
| Convection | line of convection | ||||||
| Electric field kV/m | Min Em_m = 0.233 Max Em_m = 39.223 Mean Em_m = 5.193 | ||||||
| Microphysics #/Liter |
| ||||||
| Location | (x,y) ~ (-60,30) | ||||||
| Storm Motion | 5.0 m/s west, 6.7 m/s north, gives 8.4 m/s NW | ||||||
Brief Description | Again, a core was at this location in the recent past. |
Investigator: Eric Defer
[presented on January 15, 2002]
Description: Four clouds were sampled that day. All storms except storm #3 exhibited
strong electric field.
Storm #1...
Storm #2 was a maritime case. The storm was located about 150 km away from
the 74C radar in a south-east direction. Passes were made at the western side
of the storm. Strong electric field was sensed (to 50 kV/m). The storm was
still electrically active according to the measurements of the lightning sensors.
Storm #3 was located about 50 km away from the 74C radar in a south-west
direction. The electric field was very weak but noisy.
Storm #4 was loacted west of KSC. The first pass was performed in the anvil in
the direction of the core, while second pass was done in the opposite direction.
The electric field was sensed increasing in direction to the core.
Summary - storm #1
|
Type of case
Complexity Convection Electric field Precipitation Location Focus issues
|
|
Summary - storm #2
|
Type of case
Complexity Convection Electric field Precipitation Location Focus issues
|
attached anvil.
complex. yes, still electrically active. strong. offshore, 150km away from 74C.
|
Summary - storm #3
|
Type of case
Complexity Convection Electric field Precipitation Location Focus issues
|
|
Summary - storm #4
|
Type of case
Complexity Convection Electric field Precipitation Location Focus issues
|
attached anvil.
simple. yes, still electrically active. strong. no? 50km west of KSC.
|
Instruments
|
Airborne mills
Ground KSC mills Radar WSR74C Nexrad KMLB LDAR CGLSS FSSP 2-DC HVPS CPI GOES |
ok.
ok. ok. not processed. ok. ok. ok. ok. ok. ok. ok (AREA0, Arizona, NCAR). |
HTML page with regrouped plots: Eric_plots
Detailed analysis of the measurements:
Storm #1
Storm #2
Volume scan @ 190145 UT
MER
Efield
- Increase of Ez while flying in region with reflectivity >15-20 dBZ. Ez > 0, large
difference between the M and K estimates at 190415. Ey similar while Ex different in
sign.
- FSSP and 2DC show the Citation was in cloud at 190350.
- Citation flew at the edge of the recontsructed, it can explain the difference
between the reflectivity at the flight level and the particle concentrations.
Volume scan @ 190422 UT
MER
Efield
- FSSP probe stopped working properly.
- Large particles measured while strong vertical E field measured.
- Citation flew in >10-25 dBZ region. Reflectivity along the flight pass > 20 dBZ
mostly above the Citation.
- Significant drop in temperature between the beginning and the end of the pass,
about -10 deg. C.
- Large differences between Ez during the first 35s of the scan period. After 1905
UT K-Ez and M-Ez are similar with some difference.
- Ez changed sign at about 190515 UT. Note K-Ez and M-Ez changed sign at different
times probably due to offsets. Ez was > +30 kV/m during about 50s then Ez < -30 kV/m
for about 1min 40s.
- Ey similar from the K and M methods, while Ex opposite in sign from the two
estimates. Ex and Ez changed sign at the same time.
Volume scan @ 190700 UT
MER
Efield
- The Citation flew at the lower edge of the anvil(?) (about 9 km msl).
- Large particles still measured while strong vertical Efield measured.
- Reflectivity above the Citation between 10 and 20 dBZ.
- Vertical Efield still very large < -30 kV/m, with consistent values from
the K and M matrices when the Ez is in absolute value above 20 kV/m.
- Ey similar while Ex opposite sign and with similar magnitude (on the large
scale). Note that for some period, Ey has large value relatively to Ez, suggesting
either a charge region at same altitude or a turn of the Citation.
- E small after 190910 UT. Ey changed sign when Citation was turning.
Volume scan @ 190936 UT
MER
Efield
- Still no FSSP data.
- 2DC concentration mostly constant, with large particles.
- Reflectivty at flight level 15 to 25 dBZ. Flew below or at the lower edage of the cloud.
Refelctivity > 15 dBZ sensed above the Citation.
- Ez mostly positive the 2.5 min, Ez > +20 kV/m. Note some differences of the K-Ez
and M-Ez > 50 % for some periods.
- K-Ey and M-Ey with offset (25% difference), while Ex opposite sign. E field mostly
sensed with Ey and Ez.
Volume scan @ 191214 UT
MER
Efield
- FSSP still not working.
- Total 2DC concentartion decreased slightly and increased sligthly when the citation
was flying above a region with reflectvity between 20 and 35 dBZ. 2DC large particles
concentration roughly constant during the period of the scan.
- Reflectivity at flight level bewteen 10 and 20 dBZ.
- Ez strong (M-Ez >30 kV/m until 191320; M-Ez < -10 kV/m after 191320). Ez changed
sign when the Citation was flying above a cloud region with reflectivity > 20 dBZ.
- Large differences between M-Ez and K-Ez.
- K-Ey and M-Ey very similar, while K-Ex and M-Ex opposite sign. Offsets can explain
why K&M-Ex and K&M-Ez changed sign at different times.
- Important Ey component per period.
Volume scan @ 191452 UT
MER
Efield
- Ez changed sign just before 1915 UTi, then is mostly contant (with large difference
bewteen M-Ez and K-Ez) for about 1 minute and then decreased slowly.
- Citation flew below reflectivity above 20 dBZ until 1917 UT. Note the change
in Ez after 1917 Ut when the citation was flying in 20-25 dBZ area.
- Large particle concentration decreased a little bit during the study period.
- M-Ex and K-Ex opposite sign while M-Ey and K-Ey show similar trend but with an offset.
- E field mostly due to Ez.
Volume scan @ 191729 UT
MER
Efield
- FSSP still not working.
- 2DC probe showed out of cloud just after 191940 UT.
- Reflectivity at flight level between 10 and 25 dBZ.
- Citation flew mostly in cloud region with reflectivity > 20 dBZ. Ez changed
sign at 191855 UT, time at which the citation flew in > 25 dBZ area. The reflectivity
curtain shows also more reflectvity > 20 dBz was measured below the aircraft after the time
of change of sign, while Ez vas measured with a negative sign.
- Strong efield measured. M-Ey and K-Ey similar, while opposite sign for Ex. Periods
with difference in estimates of Ez up to 50%.
Volume scan @ 192007 UT
MER
Efield
- Out of cloud.
- Self-calibration.
Volume scan @ 192244 UT
MER
Efield
- Back in cloud at 192330 UT.
- Increase of the 2DC concentrations until 192420 UT. Large particles measured.
- Reflectivity at the flight level between 10 and 25 dBZ.
- Magnitude of Ez increased after 192420 when flying in cloud region with reflectvity
below the aircraft between 15 and 25 dBZ. Sign of Ez negative.
- Again large difference between estimates of Ez.
- Ey similar from the two methods, but Ex different in sign but still same order of
magnitude.
Volume scan @ 192522 UT
MER
Efield
- In cloud until 1926 UT.
- Reflectivity at flight level between 10 and 20 dBZ, while no large particles
reconstructed by the 2DC probe.
- The reflectivity curtain shows cloud region with reflectivity between 20 and 25
dBZ measured below the aircraft. During the same period, Ez was measured negative with
conistent measurements between the two estimates.
- M-Ey and K-Ey similar (changed sign at about 192530 UT), while K-Ex and M-Ex are
opposite in sign.
- E field mostly sensed with Ez.
Storm #3
Storm #4
Volume scan @ 204649 UT
MER
Efield
- In cloud at about 204810 UT.
- E field increased about 7 s before the end of the period.
- M-Eq shows in cloud at about 204820 UT. Efield started increasing about 50s
after being in cloud, assuming a speed of 100 m/s, E field was small for about 5 km.
- M-Ex and K-Ex opposite sign, while M-Ey and K-Ey similar.
- Reflectvity and microphysics seem to not agree, probably due to the reconstruction
of the radar data.
Volume scan @ 204927 UT
MER
Efield
- In cloud until 205010 UT.
- Reflectivity along the track between 10 and 20 dBZ.
- Aircraft flew at the altitude of the lower edge of reflectivity cloud.
- Strong reflectivity > 15dBZ above the aircraft while Ez is about -20 kV/m.
- Ey and Ez same magnitude during the first 20 s of the period, while K-Ex and M-Ex
have opposite sign and differnet magnitude.
Volume scan @ 205204 UT
MER
Efield
- Mostly out of cloud, except during the 8 seconds of the period.
Volume scan @ 205442 UT
MER
Efield
- Large particles measured significantly at 205630.
- Refelctivity at flight level ranging form -15 to 10 dBZ. Strange behavior of
the refelctivity curtain for the period 205442-205540, decrease of the reflectivity.
Maybe due to reconstruction and scan strategy.
- M-Eq shows significant variation adter 2055 with NO storng E field while in cloud
according to PMS probes and reflectivity.
- Check E with a smaller scale!!!!!!!! and compute a duration of flight and a distance
without E field.
Volume scan @ 205719 UT
MER
Efield
- Reflectvity at flight level ranging from 10 to 20 dBZ.
- Reflectvivity curtain shows regions with reflectivity > 20 dBZ below the altitude
of the flight.
- Strong value of Ez. Ez close to zero when flying above a reflectivity region
>20 dBZ from the ground to 2 km below the location of the aircraft.
- K-Ex and M-Ey opposite sign and different magnitude until 205910. After seems
OK. K-Ey and M-Ey similar, with relative large value (20 kV/m) at 205910.
Volume scan @ 205957 UT
MER
Efield
- Particle concentrations larger than before.
- Reflectivity at flight level between 15 and just above 20 dBZ.
- Refelctivity curtain shows aircraft was flying in > 15 dBZ clous region +/- 2km
altitude.
- Strong Ez with some variations during the period.
- Ex differnt from the two method estimates, Ey similar, with maximum magnitude of
about 20 kv/m (at 210120).
Volume scan @ 210234 UT
MER
Efield
- Concentrations are dropping and no large particles significantly measured after
210440.
- Reflectivity at the flight level is dropping too.
- Only at the beginning of the period, reflectivity > 20 dBZ measured about 1 km
below the aircraft.
- Ez decreased during the first 80 s of the period. During that time, Ez changed
a lot.
- K-Ex and M-Ex opposite sign, Ey similar from the two methods. E field msotly due
to Ez.
Volume scan @ 210512 UT
MER
Efield
- In cloud until 210610 UT.
- Reflectivity curtain as well as reflectivity at flight level are consistent
with the PMS measurements (out cloud at 210610).
- No E field.
- check E field with a smaller scale.
Volume scan @ 210750 UT
MER
Efield
- Concentrations and reflectivity plots show similar period during which the
Citation was flying in cloud.
- No E field while flying in region with reflectivity rnaging from 5 to 15 dBz.
- Check location of the plane....
Volume scan @ 211027 UT
MER
Efield
- Citation flew about 1 km below cloud at 8 km msl.
- No field.
Volume scan @ 211305 UT
MER
Efield
- Citation flew about 1-2 km below cloud.
- No field.
Copyright © UCAR 1998 - Disclaimer - mmminfo@ncar.ucar.edu
Last Modified: 19 Jan 2002
