JRO Radar (interferometry 1-7 October, Faraday 8-12 October)
The JRO radar will be used in a double slit interferometry mode (developed by Kudeki) measuring vertical and zonal drifts plus power for the period of 1 to 7 October (skipping 6 October - Sunday). This mode will be sensitive to spread-F activity. This mode features on-B orientation for the JRO antenna, which implies that JULIA can be operated during the hours of 3 am to 3 pm. JRO operations will take place between 3 pm to 3 am. JULIA will take over operations from 3 am to 3 pm during this period. (On the 6th of October, JULIA would be set up with the small antenna to test operations with it.) Erhan Kudeki will be running the observations at the beginning, and Dave Hysell will pinch hit for Erhan around the 5th of October. He will set up the Faraday mode starting on the 8th of October.
From the 8th to the 12th of October, JRO is to be used in the Faraday mode, which will give temperatures and power profiles only in the absence of spread-F activity. If spread-F activity were to occur, then the Faraday mode measurements are not useful. The antenna is aimed at an off-B direction, which implies that JULIA cannot be connected to the JRO antenna at any time. JULIA will be connected (with 90% probability assurance) to a small antenna that is due to be constructed/installed in the next few weeks. At the present time it seems certain that simultaneous operations of JULIA and JRO (Faraday) cannot take place because the Faraday operations will interfere with the JULIA/small antenna observations. However, this still remains to be established. To test JULIA as connected with the small antenna, observations will take place during 6 October, and during the off hours of the Faraday mode during the 8th to the 12th of October.
The science objective of the Faraday observations is in part to observe the temperature and wind effects associated with the brightness wave and the midnight temperature anomaly. Satellite observations from AE-E indicate that on average the evening temperature increase tends to occur between 2030 LT and 02 LT. Observations of the JULIA operations with the small antenna are aimed to explore how well such a combination can see the pre-reversal enhancement. It therefore would appear to be a reasonable compromise to switch from the JULIA to the Faraday mode at 1830 LT. This gives JULIA enough time to see the reversal effects associated with sunset. Starting the Faraday operations at 1830 LT would provide enough time to observe the background temperatures before any effects of the temperature anomaly occurs. When the Faraday mode is in operation (1830 LT to 03 LT), JULIA will be shut down.
FPI interferometers
Two FPIs participated, one in Arequipa, Peru, with John Meriwether as P.I., and one in Antofagosta, Chile, with R. Niciejewski and T. Killeen as P.I.s. The FPI at Arequipa is to be used in a high resolution mode for either the zonal or meridional directions. The justification is that there are arguments for improving our resolution for either the zonal or meridional direction. The plan is to operate this instrument to observe the region in the west in a sequence (W,W,W,W,W,Z,N) so that 5 measurements of the zonal component would be collected in a sequence before the zenith and meridional wind measurements are obtained. This setup would apply to the period from 1 October to 7 October. These observations would be used to study the ion-neutral coupling by comparing the neutral winds with the scintillation drift measurements obtained by the Ancon drift receivers observing the F-region intersection to the west.
For the period of 8th to the 12th of October, the meridional direction would be emphasized with a sequence (S,S,S,S,S,Z,W) so that high resolution measurements in the south direction (higher signal and overlap with the Chile FPI measurements) would be obtained. The intent is to observe in high resolution the effects of meridional wind and temperature changes associated with the midnight temperature anomaly.
The FPI in Chile will look in the four directions plus zenith. Their system is likely to be more sensitive so there would seem to be no need to specify a special mode for their operations, at least for the first time out.
contributor: John Meriwether
john.meriwether@ces.clemson.edu
Since late August, the JULIA radar at Jicamarca has been making regular coherent scatter observations of E and F region irregularities as part of the MISETA and ABC campaigns. Data for the period between August 29 and September 25 may now be accessed through the Clemson Web site at
http://landau.phys.clemson.edu/julia/julia.html
Power maps, Doppler, and zonal interferometric drifts are available for viewing. Out of a total of 25 evenings of observations, topside spread F occurred on 18 and bottomside layers on an additional 5.
JULIA Data for the second half of October will be made available as soon as possible. Daytime E region observations will ultimately also be added to the archive. Likewise, electron density and temperature data for the week of October 7-12 taken in Jicamarca's Faraday mode should appear there shortly. All of these processed data are preliminary and should be regarded as "first look" in nature.
contributor: Dave Hysell
daveh@vlasov.phys.clemson.edu
During the first week of the MISETA III Campaign JRO radar was operated in an IS drifts/radar interferometry mode (Sept 30-Oct 5). Very little spread-F activity was detected in this period. Only very weak bottomside spread F was observed during Oct 1-Oct 4. Sept 30 and Oct 5 exhibited some weak topside spread F in addition to bottomside spread F. F-region vertical drifts reversed very early in the afternoon, and pre-reversal enhancement was virtually absent throughout the period. Post sunset F-region peak height was consistently below 300 km.
Despite the absence of ``exciting spread-F'', radar measurements went very well. High quality IS drifts data were acquired. The data base should be useful to study the bottomside spread F phenomenon. We hope that comparisons of bottomside spread-F and incoherent scatter levels will enable absolute cross-section estimation for the 3-m component of bottomside irregularities. Jicamarca ionosonde was also operated throughout the period and drifts comparisons between the radar and the ionosonde will be conducted.
contributor: Erhan Kudeki
erhan@uiuc.edu
The weather at Arequipa was clear during the first week of MISETA observations. The FPI operated during this period featuring zonal measurements.
The Michigan FPI is nearly operational. Rick Niciejewski has gotten FPI fringe measurements at the rate of several minutes per fringe at the beginning of the night so the results look to match expectations. Unfortunately, the loss of a dome has deferred automatic operations. A replacement is in Chile now awaiting custom clearance so automatic operations can be expected within the near future.
Click here to go to the Clemson FPI data.
Contributor: John Meriwether
john.meriwether@ces.clemson.edu
contributor: Cesar Valladares
cesar@dl5000.bc.edu
Starting on Sunday 29 Sep. the Digisonde at Jicamarca made measurements ionograms and drift in a 15 minute sequence, one ionogram followed by several multi-frequency drift measurements. To be compatible with the operation of the ISR, the DPS ran with an IPP of 50 ms.I checked the data until Thursday morning (10/3) when I left for Lowell, and all data look very good.
Checking also through all the data of September we found strong bottomside spread F every night until and including Sep 30. The next three nights the pattern broke and we observed only weak spread F. Spread F times (UT) were:
day 275 (1 Oct) 0045 to 1030 (Monday/Tuesday)
day 276 (2 Oct) 0130 to 1115, strong spread 0845 to 1015
day 277 (3 Oct) 0100 to 0530
Click here to see Digisonde data taken during the campaign.
contributor: Bodo Reinisch
reinisch@cae.uml.edu
Ted Beach is operating a GPS receiver at Ancon which reported seeing some scintillations on Sunday evening. Jim Gary is operating a GPS receiver in Tucaman which is functioning well and has seen scintillations but we do not have dates and times of specific events yet. We are still trying to get a GPS receiver operating in Natal, Brazil.
contributor: Paul Kintner
paul@ee.cornell.edu