3. Byrd Station

ID#: 
	8903
Date: 	
	1 Dec. 80  Julian day 336.
Time: 	
	Departed McMurdo 2030 Z 30 Nov.  Arrived Byrd 2345 Z.
	Visited AWS unit 0145 Z to 0215 Z 1Dec 80.  Departed Byrd 2300 Z 1 Dec.
	Arrived McMurdo 0215 Z 2 Dec.

Background:  
	The AWS unit at Byrd has been in operation since Secember 78.  The site is located about a mile east of the present Byrd Surface Camp.

Equipment:  
	Spare boom with sensors, aerovane, prop, tools, VOM meter, shovells, and camera

Weather:  
	Low overcast skies and blowing snow on arrival.  Weather cleared after a few hours.  When servicing station, skies were 2,000 feet scattered with ice crystals present.

Trip:  
	Ski-equipped C-130 departed McMurdo with Evans and Savage aboard.  Visibility and horizon definition very poor on landing.  Weather cleared after a few hours and we travelled to site via D-4 tractor towing sled with people and equipment.  Half hour to reach site.  AWS has been buried by drifting snow so that height of aerovane above surface is only about 7 feet, and electronics box is partially buried.	

	Evans conducted RTG survey and declared site safe.  Aerovane replaced and VOM used to verify correct match between aerovane and boom.  Upon opening the electronics box, found ground wire to Zener diode not connected (opening box may have loosened it).  At the time I did not realize the significance of the wire and did not reconnect it.  Several hours later I realized that the wire should be connected (Zener provides constant load for RTG output) so I returned to site and reconnected it.

Observations:	
	Altitude too great to use microbarometer.  Thermometer was a -30 C to +50 C mercury-in-glass.

	time 			temperature
	0200 Z  1 Dec		-22.0 C

	estimated wind speed:  8-10 knots
	estimated wind direction:  Southwest

AWS Output:  
	for 1 December 1980
	time		temperature	pressure	wind
	2320 Z		-18.7 C		817.2 mb	356 deg at 7.4 kt
	2310 Z		-18.0 C		817.3 mb	
	2300 Z		-17.8 C		817.2 mb
	2250 Z		-15.7 C		817.2 mb
	2240 Z 		-15.3 C		817.3 mb

	mean wind speed:  7.4 knots
	mean wind direction:  011 degrees true
	signal strength:  -114 dbm

Notes:  
	1. Accurate comparisons between observed parameters and AWS output not possible at this time due to lack of AWS output.
	2. The large difference between observed and AWS output wind direction is reason for concern.  Of course the AWS output is for 21 hours later than the observed data, and the wind may have shifted.

Recommendations:
	1. Careful check of all parameters, particularly wind direction, should be made next visit.
	2. Drift rate is high and station is already partially buried.  A new tower section needs to be added in order to increase the height of the aerovaneabove the surface.  Also, the electronics box needs to be repositioned higher up on the tower.  Evans and Smith will attempt to return to the station this season to do this work.

How to Find:	
	The site is located 4500 feet (1370 meters east of Byrd Surface Camp.  First drive to aurora tower (the aurora tower and the old balloon inflation tower east of it are the two wooden buildings visible above the snow over the main complex at old Byrd Station).  Drive east from the aurora tower past the VLF lab site (40 foot tower with hatch and winch).  Continue east another 2000 feet past the VLF tower to the AWS site.