Electromagnetic fields recorded in mesocyclones.

Initial findings taken from ongoing field research, seeking to better understand the relationships between electrical charge, magnetic fields, and the evolution of vortices, are presented. Despite inherent difficulties in collecting real-time data associated with vortices, measurements of magnetic fields close to and within dust devils, mesocyclones, and a hurricane were successively recorded using magnetometers.

Speculations about possible mechanisms accounting for the variability in the electromagnetic fields observed are offered, although without quantitative proof. Of particular interest for additional research are: i) measurements showing an increase in the magnetic field of the mesocyclones' torus compared to the decreasing magnetic fields found in the center; if) a sharp drop in magnetic field readings upon entering the eye of Hurricane Wilma; and iii) a consistent change in the direction of rotation of large dust devils as they moved across fields with significantly different pH soil values.

1. Introduction

After observing what appeared to be magnetic field lines in the debris field of tornadoes and non-rotating spoke-like projections that appeared to be the influence of magnetic field lines in 4-second NASA satellite images of Hurricane Guillermo 2 August 1997 from GOES-9, (http://rsd.gsfc.nasa.gov/rsd/movies/preview.html), experimental investigation into the variability of surface electromagnetic fields of mesocyclones was initiated. Current literature of electromagnetic theory and tornadoes includes research measuring how severe storms become electrified and how variations in type and flash rates of lightning relate to the type of storm and its evolution as conducted during STEPS (Severe Thunderstorm Electrification and Precipitation Study) project (STEPS 2004) Previous magnetic field research involving tornadoes (Brook 1967) showed that large currents of electricity (up to 225 Amperes) were generated during the tornadoes' lifetimes. Brook (1967) also mentioned one instance where a tornado was detected at a distance of 150km by using a magnetometer, but that more observations were needed to confirm that such large charges actually occur with tornadoes. Vonnegut (1960) speculated that tornadoes were powered by the parent thunderstorms that caused rotation similar to an electric motor. If this is true, then there will be a stronger magnetic field within the rotation. However, because of the difficulty in obtaining inner-vortex data, there is a lack of magnetic field research with regards to tornado generation.

Our magnetic field recordings of Hurricane Wilma coupled with our observations of dust devils led us to speculate on the role of electromagnetic fields during mesocyclones and how tornadoes may develop. The purpose of this paper is to share with the scientific community our recordings of magnetic fields associated with vortices of various spatial scales and future plans for additional research. Although considerable more research is needed, we speculate about the potential of utilizing magnetic field measurement as an additional means to current methods for anticipating tornadogeneis.

2. Data Collection and Initial Results

a. Dust devils

The magnetic fields of dust devils were recorded in the San Joaquin Valley of California in 2003. The San Joquin Valley consists of thousands of square miles of flat terrain, punctuated by farm fields. Research was conducted in farm fields that were sectioned into blocks of one square mile, with each square mile being connected by straight dirt roads. The freshly tilled soil in each block had previously yielded cotton, onions, or wheat.

A single-axis geomagnetometer was used to record the magnetic fields. The smallest and most sensitive unit was purchased online from Less EMF, Inc. Measuring 3 x 4 x 7 inches and operating on 9V batteries with an AC power adapter included for extended bench-top use, the magnetometer is totally portable. An axial probe (High Sensitivity Hall Generator) with coiled cable was included and provided a nearly flat response from DC to 10+Hz, an easily readable 3.5 digit bipolar display, and four ranges: 0-2, 20, 200, and 2,000 milligauss, with a 5% error guarantee.

The magnetometer was mounted on a standardized crate, also known as an "apple box," and fitted with a pinhole camera above to record the digital display. The gauss probe was mounted stationary at an upward position of a 45-degree angle and was set up on the ground facing due north. The magnetometer was then calibrated to account for the Earth's ambient magnetic field, approximately 500 milligauss. When a dust devil was observed, the magnetometer was placed on the ground in the path of the dust devil to record its magnetic field.

Sixteen large dust devils were observed in two large fields and captured on video. We speculate that dust devils electrify themselves through the rotation of dust particles that collide to create an electrical charge, and the moving charge then creates a dipole moment to make a magnetic field. For theories regarding self-excitation leading to vortex generation, see Davies-Jones and Golden (1975), Wilkins (1964), and Vonnegut (1960).

Of particular interest was the change in the direction of the dust devils' rotation as they moved from the field of origin into an adjacent field. The pH levels of the soil in each field was tested. In the tilled field where wheat had previously grown, the soil tested at pH 7 (neutral). In the tilled field to its south, cotton had recently been harvested, and the pH reading was 9. All sixteen large dust devils rotated in a clockwise direction in the field with soil pH levels of 7; however, once the dust devils crossed into the adjacent field, they changed direction, spinning counter clockwise. We speculate that this consistent change in rotation may be due, in part, to the alkaline material present in the second field, causing the particles to charge positive as opposed to the negative charge induced by the pH 7 balance soils. These initial findings will be subject to further research to be conducted in the San Joaquin Valley this spring (2008).

When editing the finished video footage of the dust devils, it was discovered that in all 41 recordings there was a glitch in the footage as the tail end of the dust devil passed through the DV camera. We speculate that the magnetic field present with the dust devils interfered with recording the magnetic information onto the mini DV tape.

Finally the barometric pressure inside and outside the dust devils was also collected using a weather watch containing a barometer. In the successful attempts, barometric pressure drops inside the dust devils of 2-3 millibars were recorded; however, it cannot be discerned whether the pressure drops were due to the dust devils' rotations and electrical charges or due to temperature changes.

b. Hurricane Wilma

On 20 October 2005, we participated with the National Oceanic and Atmospheric administration's (NOAA) Tampa, FL-based Hurricane Hunters on two missions to record the magnetic fields of Hurricane Wilma aboard a Gulf Stream IV-SP (G-4) and a WP-30 Orion Turboprop (P-3). On the first mission, we used a single-axis calibrated geomagnetometer (identical to the magnetometer we used in the dust devil investigations). The magnetometer was placed on the window using suction cups, and a gauss probe was held on by tie wire and aimed downward at a 50-degree angle (Fig. 1).

[FIGURE 1 OMITTED]

On the second mission, the magnetometer was placed on the inside window of a WP-30 Orion turboprop (P-3), again using suction cups. A video camera was used to record each radiosonde drop and then panned over to record the digital display magnetic field reading of the geomagnetometer for reference.

The G-4 mission flew the outer perimeter of the hurricane at an altitude of 34,000-39,000 feet (Fig. 2). The G-4 mission landed 9 hours later at McDill Air Force Base (AFB), and the same calibrated magnetometer was loaded on board the P-3 mission that flew into the eye.

[FIGURE 2 OMITTED]

Although the magnetic field readings of the magnetometer changed when the aircraft changed directions, the principal interest of study here was the changes in the magnetic field that occurred when the aircraft was traveling in a straight line. The largest variances were recorded during the P-3 missions into the eye of the storm. As the aircraft maintained a steady and straight line course, a considerably higher magnetic field reading was recorded while in the hurricane's rotating precipitation shield. Once the aircraft entered the clearing of the eye, the readings dropped significantly. Notice that in Fig. 3, while traveling in the same northwesterly direction, a reading of 414 milligauss was recorded with SONDE drop #4 and 77 milligauss was recorded with drop #5. The same general pattern of results occurred from SONDE drop #10, recording a reading of 58 milligauss, and #11, recording a reading of 376 milligauss.

[FIGURE 3 OMITTED]

c. Mesocyclones

Magnetic fields associated with nine mesocyclones (Table 1) were recorded over 31 days during May and June of 2006. As in the NOAA investigations of Ilurricane Wilma, video cameras were used in conjunction with the magnetometers, enabling us to review the exact times the recordings took place in relation to the mesocyclones. Due to the necessary expediency involved in storm chasing, it was not always possible to recalibrate the Honeywell HMR 3000 3-axis magnetometers before deploying at a given test site. In those cases, a close approximation of the magnetic field for a specific location was achieved by assuming that the Earth's surface ambient magnetic field was 500 milligauss. Also, for the two consecutive days immediately following the storms, each recording site was revisited. There, additional readings were obtained under clear skies, establishing a base line on which to further interpret the mesocyclones' magnetic field measurements.

Table 1. Dates and locations of mesocyclones recorded.

5-14-06  Medina, TX
5-22-06  Jackson, CO
5-23-06  O'Neil, NE
5-23-06  Norfolk, NE
5-27-06  Bismarck, ND
5-28-06  Langdon, ND
5-30-06  Shindler, OK
5-31-06  Boise City, OK
6-06-06  Clarksville, TX

Different methods were attempted for gathering recordings of the storms' magnetic fields, including equipping 3-axis geomagnetometers and data loggers into rockets for launching into the storms and portable pods for recording readings as the storms were intercepted using a motorcycle and car.

The first chase (14 May 2006-Medina, TX) was in conjunction with Dr. David Arnold, formerly of Ball State University. Upon consulting with Dr. Arnold, stationary pods (Fig. 4) were placed in front of the anticipated path of the approaching mesocyclones. This strategy allowed the magnetic field readings to be obtained before, during, and after the mesocyclones' passage. The stationary pods method provided the best overall results.

[FIGURE 4 OMITTED]

3. Storm Chase Results

Presented in this section are examples of electromagnetic signatures recorded during the storm chases. Since Microsoft Excel cannot accommodate more than 67,000 rows of data, the magnetic field recordings were edited to one reading per second and then down to one reading per minute in order to produce the final results shared here. The electromagnetic signatures obtained are indicative of instrument calibration, lightning strikes, cloud cover, and mesocyclones passing nearby or overhead. The readings were recorded on 14 May 2006 near O'Neil, NE (Table 2) and on 31 May 2006 near Boise City, OK (Table 3).

Table 2. Recordings of Mesocyclone at O'Nell, NE.

Date: 23 May 2006
Place: O'Neil, NE

                         Pod 1          Pod 2          Pod 3

Street:                  US-275         US-20          US-275
City:                    O'Neil         O'Neil         Inman
State:                   NE             NE             NE
Zip:                     68763          68763          68742
# on the Map             #24            #25            #26

Time start recording:    16:45:31       17:11:32       17:13:58
Time stop recording:     18:09:00       18:44:05       19:11:00

Video start recording:   Yes            Yes            Yes
Map start recording:     Yes            Yes            Yes
  Latitude:              42.45559 N     42.40806 N     42.36110 N
  Longitude:             98.63333 W     98.56473 W     98.49550 W
Baron start recording:   Yes            Yes            Yes
Remarks:                 Not Raining    Not Raining    Not Raining

Video stop recording:    Yes            Yes            Yes
Map stop recording:      No             No             No
Baron stop recording:    No             No             No

Result:                  6-AA battery   6-AA battery   6-AA battery
                         working        working        working
                         Data Recorded  Data Recorded  Data Recorded

a) O'Neil storm chase

The O'Neil storm readings were taken approximately 5 miles apart (Fig. 5). Recordings of the magnetic field over time at each of the three pods [1-3] are shown in Fig. 6 (a-c).

[FIGURE 5 OMITTED]

[FIGURE 6 OMITTED]

For each of the three pods, the first vertical line seen in the time series represents the magnetometers' calibration; the other sharp vertical spikes recorded by pods 2 and 3 signal individual lightning strikes that occurred nearby. The series of rapid rises and falls in the magnetic field readings, seen at the beginning and end of the time series, are associated with the departure of the tail end of a first storm and its mesocyclone and the approach of a second storm. The prominent "leveling out" of the magnetic readings to a constant value (flat horizontal line) is largely indicative of the Earth's ambient magnetic field. The location of the pods and the timing of their placement relative to the storms' paths in the O'Neil chase were less than ideal for capturing a detailed signature of the storms' mesocyclones.

b) Boise City storm chase

Three stationary pods (Fig. 7) were deployed during the Boise City, OK chase. Unimpressive results were obtained from pod 1 (Fig. 8a) and pod 3 (not shown). Pod 1 calibrated itself within the first ten seconds of deployment and very briefly recorded the magnetic field at the very tail end of a storm moving southward. As skies cleared, the plot points seen in Fig. 8a leveled out to around 132 milligauss. The jump in values seen at the end of the time series occurred as the magnetometer was retrieved and loaded into the chase vehicle.

[FIGURE 7 OMITTED]

[FIGURE 8 OMITTED]

The second magnetometer (pod 2) was deployed along RTE 325 about 15 miles west of Boise City (Fig. 7). The deployment took place prior to the approach of a developing, quasi-stationary supercell with marked rotation in the clouds clearly observed. The very slow movement of this storm made for excellent observation as the mesocyclone eventually passed directly overhead of the stationary pod. A drop in atmospheric pressure of 7 millibars was recorded beneath the center of the mesocyclone.

The resulting recording of the mesocyclone's magnetic field (Fig. 8b) shows considerable detail in contrast to the other recordings previously shared. Note that the pod was positioned at 17:44 (local time) and quickly calibrated to 164 milligauss. As the outer portion of the mesocyclone very slowly approached the magnetometer, an increase in the magnetic field values began at 17:45. At 18:00, 16 minutes later, the reading peaked near 192 milligauss. Once the center of the mesocyclone moved directly over the magnetometer, a minimum of 172.76 milligauss was recorded at 18:13. As the rear portion of the mesocyclone approached, the magnetic fields began once again to increase, peaking near 200 milligauss at 18:25. When the tail end of the mesocyclone passed over the magnetometer at 18:38, a minimum of 170 milligauss was recorded. Finally, the readings leveled off to an average near 178 milligauss, holding at the same values for three hours until the magnetometer was turned off. The magnetic field readings recorded for two consecutive days (with mostly clear skies) following the storm's departure also held steady with no significant variance observed.

c) Discussion of Boise City mesocyclone results

For illustration purposes (Fig. 9), the actual time series of magnetic field values (from Fig. 8b) have been "stretched out" to enhance the signals recorded from the very slowly moving and developing Boise City mesocyclone. An ideal graphical representation of the magnetic field lines and its associated mesocyclone are shown above the time series as they might have appeared while passing over the stationary pod. The small scale oscillations seen in the magnetic field values may have been due to variations in the mesocyclone cloud base which ranged from 800-2,000 feet AGL. If true, the mesocyclone may have acted as a Ferro magnet, which means that the magnetic field at the cloud's base should, in theory, be much stronger.

[FIGURE 9 OMITTED]

In general the Boise City mesocyclone magnetic field readings, recorded from the ideally placed magnetometer, are consistent with the magnetic field readings recorded with Hurricane Wilma. Moreover, the outer portion of the mesocyclone had the highest magnetic field readings, while the center of the mesocyclone showed a much lower magnetic field reading. These lower magnetic field readings in the center of the mesocyclone corresponded with the lower magnetic field readings recorded in Hurricane Wilma's eye, while the highest magnetic field readings found in Wilma's roting precipitation shield corresponds to the highest mesocyclone readings observed with the outer portions of the mesocyclone.

Based upon these empirical observations and recordings the question remains how then, could a mesocyclone create a magnitic field? Dr. Marty Simon, Professor Physics Department, UCLA, suggested that perhaps the magnetic field was created by a moving charge. In his opinion, this was not a case of spin-polarization, as the dipole moments would have trouble lining up while moving (M. Simon 2006, personal communication).

4. Conclusions

The inherent difficulty with measuring magnetic fields near and within vortices in real-time has impeded the progression towards a better understanding of the relationships between electrical charge, magnetic fields, and the evolution of vortices. Using magnetometers in real-time, we have obtained magnetic field measurements for vortices of various scales.

Field results from our ongoing research thus far include evidence of apparently anomalously low magnetic feild readings near and within the vortices of mesoscyclones and the eye of Hurricane Wilma. Relatively high readings were measured along the mesocyclones' outer portions and within Hurricance Wilma's rotating precipitaion shield. Also observed were small variatins in the magnetic fields of mesorcyclones as they passed over the magnetometers. These variations may be associated with changes in the mesocyclones' cloud bases.

Table 3. Recording of Mesocyclone at Boise City, OK.

Date: 31 May-2 Jun 2006
Place: Boise City, OK

                        Pod 1              Pod 2         Pod 3

Street:                 US-287             SR-325        CR-T
City:                   Springfield        Boise City    Springfield
Zib:                    81073              OK            C0
State:                  CO                 OK            CO
#on the Map             #48                #49           #50

May 31, 2006
Time start recording:   17:38:52           17:27:00      16:49:14
Time stop recording:    23:56:00           22:45:00      23:42:36

June 1, 2006
Time start recording:                      11:48:00
Time stop recording:                       14:18:00

June 2, 2006
Time start recording:                      13:59:00
Time stop recording:                       15:22:00

Video start recording:
Map start recording:
  Latitude:              37.30892 N        36.73373 N    37.23582 N
  Longitude:            102.61501 W       102.74758 W    96.65726 W
Baron start recording:
Remarks:                Not Raining       Not Raining    Not Raining

Video stop recording:
Map stop recording:
Baron stop recording:

Result:                 6-AA battery      6-AA battery   6-AA battery
                        working           working        working
                        Data Recorded     Data Recorded  Data Recorded
                                          (All 3 days)

Results to date care subject to confirmatin given the small smaple size of vortices along with the considerable speculations (without quantitative proff) about the mechanism(s) accounting for their evolutions and the role of the magnetic field and electrical charge. However, support additional research support these initia findings there is ample reason to further investigage the possibility that as the intensity of the magnetic field increased in a toroidal field, the intensity of the magnetic field within the eye steadily decreases. Should this be true, then perhaps additional insights and/or methodologres for understanding and anticipating tornadogenesis might be found. A conceptual model (H-factor) for these speculations based upon this research is shared (Fig. 10). Hopefully, this research will promote additional investigation that will mcrease the understanding of the role of magnetic fields and electrical charges as they relate to the evolution of vortices.

Authors

Richard Heene is lead investigator and a co-host of The Science Detectives, a documentary series investigating the mysteries of science. Since 1974, Richard has been working on various gravity propulsion systems using rotating magnetic fields, and has also become a successful inventor, with such inventions as the magnetic-driven bicycle, electricity-less lights for cameras, and a device that extracts the contents from containers in three seconds. After graduating in 1979, Richard began work as a carpenter in Texas, where he experienced firsthand the destructive results of the 1979 Waco F5 tornado. That event prompted him to begin researching tornadoes. Currently a director and producer, Richard has produced Box Time, a children's' educational video series. He also hosts his webcast radio show, the Science Detectives, and co-owns (with his wife) My You Me Productions, a video production and post-production facility in Colorado. Richard is currently producing a documentary based on this research.

Robert (Scott) Stevens studied synoptic meteorology at the University of Kansas. A member of the National Weather Association, Scott has worked for 18 years in the field of broadcast TV in Topeka, Kansas; Omaha, Nebraska; Tulsa, Oklahoma; Albany, New York; and Pocatello, Idaho. Scott currently resides in Fort Collins, Colorado, and is also a co-host on The Science Detectives.

Barbara Slusser graduated from Knox College, Galesburg, Illinois, and Oklahoma State University, Stillwater with degrees, in Comparative Psychology, Zoology, and Wildlife Biology. As a research associate at Colorado State University, she began editing and producing camera-ready books dealing with statistics and population modeling as well as assisting in producing symposiums and their associated publications. Her interest in tornadoes began at an early age when she and her family experienced firsthand the power of an F5 tornado during the April 1965 Palm Sunday outbreak. Since that time, she has also experienced several other F4 and F5 tornadoes. Barbara currently resides in Fort Collins, Colorado, and owns her own publishing and editing company, as well as being a co-host on The Science Detectives.

References

Brook, M., 1967: Electric currents accompanying tornado activity. Science, 157, 1434-36.

Davies-Jones, R. P., and J.H. Golden., 1975: On the relation of electrical activity to tornadoes. J. Geophys. Res., 80, 1614-1616.

Johnson, G. L., 1997: New energy source tornadoes. Power Engineering Review, IEEE Publication, 12, 20-23.

STEPS, 2004: Severe thunderstorm electrification and precipitation study. Bull. Amer. Meteor. Soc., 85, 1107-1125.

Vonnegut, B., 1960: The electrical theory of tornadoes. J. Geophys. Res., 65, 203-12.

Wilkins, E.M., 1964: The role of electrical phenomena associated with tornadoes. J. Geophys. Res., 69, 5425.

Acknowledgments

We, the authors, wish to acknowledge Dr. Marty Simon of the University of California, Los Angeles, for helpful discussions regarding the research results; Dr. David Arnold, formerly of Ball State University, for allowing us to accompany his tornado chase team and for his advice and suggestions regarding the use of the pods; Dr. James R. Slusser, Colorado State University for his review of the manuscript; Brian Waldrop and Clint Perkins, storm chasers; and Mayumi Heene, for all the love and support she provided Richard during these investigations. All of your comments, advice, and support are appreciated.

Our special thanks go to Dr. Jim D. McFadden, Program Manager, Kristy L. Wheless and Jack R. Parrish, all of NOAA's Aircraft Operations Center, for their assistance in getting Richard and Clint aboard flights into Hurricane Wilma. We'd also like to thank the entire flight crews on the Orion P3 and Gulfstream 4.

We are grateful to Gregory Dace of Acumen Instruments for providing the data loggers and his help with programming the Honeywell magnetometers. We are also grateful for the assistance and sponsorship provided by Cliff Windham, Program Manager of Mobile Threat at Baron Services Inc.

Richard Heene, Robert Stevens, and Barbara Slusser Science Detective Research Group

Fort Collins, Colorado

Corresponding Author:Richard Heene

Science Detective Research Group,5434 Fossil Ridge Drive West

Fort Collins, CO 80525

Email: [e-mail]