Topics

[EXTERNAL] [SUG] HAARP Radio Jove Event on 24 July 2020


Shing Fung
 

Hi Whit,

 

Very interesting event. Can you fill in some details so I can understand the observations a little better?

  1. Does K4 mean Kp =4?
  2. 1600-1700 UTC should be 0600-0700 local time in Alaska?
  3. What coordinate system is used for your magnetic field measurements Bx, By, and Bz?

 

Thanks,

Shing

 

From: <sug@sug.groups.io> on behalf of Whit Reeve <whitreeve@...>
Reply-To: "sug@sug.groups.io" <sug@sug.groups.io>
Date: Friday, July 24, 2020 at 11:23 PM
To: "sug@sug.groups.io" <sug@sug.groups.io>
Subject: [EXTERNAL] [SUG] HAARP Radio Jove Event on 24 July 2020

 

I happened to be watching a client connection on the HAARP RJ at the same time I was watching a K4 magnetic field event unfold on my Anchorage SAM-III magnetometer. I noticed two things happening at the same time.

I've attached the RSP-II plot from 1600-1700 UTC and the SAM-III magnetogram for the 24 h period. Note the deep dive in all three components (Bx, By and Bz) of the magnetic flux density and the minimum around 1620. SWPC reported there may have been some influence by a slow moving CME during the UTC day. There were no reported solar radio events.

If there was a decrease in ionospheric absorption, it was quite strong, maybe too strong.

This post is to query speculation and also to warm up for when I get my SUG spectrometer installed at HAARP.

Whit




--
Whitham D. Reeve
Anchorage, Alaska USA
---


Whit Reeve
 

Hi Shing :

1. Yes, K4 -> Kp = 4;
2. Our goofy daylight savings/standard time is as screwed up as Hogan's goat. HAARP is 145 deg. W longitude, so local solar time is about what you stated;
3. The magnetometer is setup with geographic coordinate system referenced to true north; therefore, Bx = N-S true, By = E-W true and Bz = vertical.

It's interesting that Bz (vertical) took a dive - usually Bz is affected most by local magnetic events.

Whit
--
Whitham D. Reeve
Anchorage, Alaska USA
---


Shing Fung
 

Hi Whit,

 

Ok, good.

For #3, what are the positive directions for Bx, By, and Bz? In the northern polar region, the Earth’s field is directed downward toward the ground; so is Bz-positive pointing downward (roughly parallel to the field direction) or upward (geographically)?

 

Shing

 

From: <sug@sug.groups.io> on behalf of Whit Reeve <whitreeve@...>
Reply-To: "sug@sug.groups.io" <sug@sug.groups.io>
Date: Saturday, July 25, 2020 at 12:40 AM
To: "sug@sug.groups.io" <sug@sug.groups.io>
Subject: Re: [EXTERNAL] [SUG] HAARP Radio Jove Event on 24 July 2020

 

Hi Shing :

1. Yes, K4 -> Kp = 4;
2. Our goofy daylight savings/standard time is as screwed up as Hogan's goat. HAARP is 145 deg. W longitude, so local solar time is about what you stated;
3. The magnetometer is setup with geographic coordinate system referenced to true north; therefore, Bx = N-S true, By = E-W true and Bz = vertical.

It's interesting that Bz (vertical) took a dive - usually Bz is affected most by local magnetic events.

Whit
--
Whitham D. Reeve
Anchorage, Alaska USA
---


Whit Reeve
 

Hi Shing - I'm not sure I know the answer. The convention we have with the SAM-III magnetometer is to orient the sensors in a specific direction and not a specific polarity. For example, we orient the vertical (Bz) sensor with the sensor pins pointed UP.

I do know that professional magnetometers in Alaska indicate the same direction; ie, when SAM-III Bz flux density decreases, so do all the other "nearby" magnetometers. The attached magnetogram is from Trapper Creek magnetometer, which is around 50 km north of Anchorage and more-or-less equivalent. I can't explain the drop-out at the critical time.

I've also attached the magnetogram from Gakona, which actually is collocated with HAARP. The magnetometer at HAARP is only a few hundred m from the Radio Jove antenna.

Whit




--
Whitham D. Reeve
Anchorage, Alaska USA
---