NSA/SONDE/C1 - Broken temperature sensor

It appears that the temperature sensor on this radiosonde broke after launch.  There is a 
sudden drop of 12 degC in 2 seconds and the remaining tdry values seem to be about 30 
degC low.

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Humidity, relative(rh)
• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)

NSA/SKYRAD/C2 - Reprocess: Incorrect datalogger program affecting PIR1 and PIR2 
downwelling longwave

The excitation delays using in measuring the PIR1 case thermistor commonly named "Case1" 
and the PIR2 dome thermistor called "Dome2" were discovered to have been incorrectly set 
to 0 in the Skyrad datalogger program when the new CR23X based Skyrad loggers were 
installed.  The result of no delay in these measurements results in an error in the measured 
resistance of the thermistors, Case1 and Dome2 and thus the calculated PIR1 and PIR2 
irradiances.  The errors are inversely proportial to temperature.

Users can apply temperature dependent irradiance corrections shown in the table below.  
Recall that the reported uncertainty of PIRs is typically +-.25% to +-.5% or 1 to 2 W/m2.  
The error corrections become the same order of magnitude or larger than the instrument 
uncertainties at or below 260K or 9F.

Correction Table for Skyrad (TWP and NSA) DIR1 and DIR2 Irradiance				
	DIR1	DIR1	DIR2	DIR2
T[F]	Tcase[K]	Correction[W/m2]	Tdome[K]	Correction[W/m2]
109.4	316.13	0.00	316.13	0.00
100.5	311.20	-0.15	311.20	0.12
93.2	307.14	-0.12	307.14	0.10
87.0	303.70	-0.10	303.70	0.08
81.6	300.70	-0.17	300.70	0.14
77.0	298.15	-0.22	298.15	0.18
59.4	288.35	-0.34	288.35	0.27
47.4	281.72	-0.23	281.72	0.18
38.5	276.74	-0.42	276.74	0.34
31.3	272.77	-0.48	272.77	0.38
25.4	269.48	-0.61	269.48	0.49
20.3	266.67	-0.67	266.67	0.54
16.0	264.25	-0.82	264.25	0.66
12.1	262.11	-0.98	262.11	0.79
8.7	260.19	-0.97	260.19	0.78
5.6	258.46	-1.07	258.46	0.86
2.7	256.89	-1.17	256.89	0.94
0.1	255.44	-1.33	255.44	1.07
-2.3	254.11	-1.41	254.11	1.13
-4.5	252.87	-1.43	252.87	1.15
-6.6	251.71	-1.52	251.71	1.22
-8.5	250.63	-1.63	250.63	1.31
-10.4	249.62	-1.73	249.62	1.39
-12.2	248.58	-1.79	248.58	1.44
-15.4	246.82	-1.93	246.82	1.55
-18.3	245.23	-2.05	245.23	1.65
-20.9	243.78	-2.22	243.78	1.78
-23.3	242.44	-2.36	242.44	1.89
-25.5	241.21	-2.58	241.21	2.07
-27.5	240.07	-2.65	240.07	2.13
-29.5	239.01	-2.75	239.01	2.21
-31.3	238.00	-3.02	238.00	2.42

• Irradiance, longwave, downwelling, hemispheric, thermopile (Shaded Pyrgeometer2)(inst_down_long_hemisp_shaded2_tp)
• inst_down_long_shaded1_dome_resist
• inst_down_long_shaded2_case_resist
• inst_down_long_shaded2_dome_resist
• inst_down_long_shaded1_case_resist
• Irradiance, longwave, downwelling, hemispheric, thermopile (Shaded Pyrgeometer1)(inst_down_long_hemisp_shaded1_tp)

• down_long_hemisp_shaded2_std
• down_long_hemisp_shaded2_min
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer2(down_long_hemisp_shaded2)
• down_long_hemisp_shaded1_min
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer1(down_long_hemisp_shaded1)
• down_long_hemisp_shaded1_std
• down_long_hemisp_shaded1_max
• down_long_hemisp_shaded2_max

NSA/SKYRAD/C2 - Station noise problem

From 8/18 through 8/20 the logger battery voltage (vBatt) periodically jumps in voltage 
with noise on all differential measurements.  The qc fields caught most of the 
down_long_hemisp MAX failures but the bad short_direct_normal, down_short_hemisp and 
down_short_diffuse_hemisp values were not flagged.

Noise returned on 8/22, 8/25-26 and 8/27-28.

Site Ops checked and re-routed the Sky stand grounds on 8/21 and performed additional 
ground re-work on 8/28.  After that date, noise has not returned to the Skystand logger 
instruments.

• inst_down_long_hemisp2_case_resist
• inst_down_long_hemisp2_tp
• inst_down_long_hemisp1_tp
• inst_sky_ir_signal
• inst_down_long_hemisp1_dome_resist
• inst_global
• inst_direct_normal
• inst_down_long_hemisp2_dome_resist
• inst_down_long_hemisp1_case_resist
• inst_diffuse

• vBatt
• inst_down_long_hemisp1_case_temp
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• sky_ir_temp_max
• sky_ir_temp_min
• inst_down_long_hemisp2_case_temp
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1(down_long_hemisp1)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2(down_long_hemisp2)
• down_short_diffuse_hemisp_std
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• down_long_hemisp2_max
• inst_down_long_hemisp1_dome_temp
• down_long_hemisp1_min
• inst_down_long_hemisp2_dome_temp
• Temperature, Sky Infra-Red(sky_ir_temp)
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• down_short_hemisp_std
• short_direct_normal_std
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• sky_ir_temp_std
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• inst_down_long_hemisp2_tp
• down_long_hemisp2_min
• inst_down_long_hemisp1_tp
• down_long_hemisp2_std
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• down_long_hemisp1_max
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• down_long_hemisp1_std

NSA/SKYRAD/C2 - IRT failure

The IRT failed and was replaced.

• inst_sky_ir_signal

• sky_ir_temp_max
• sky_ir_temp_min
• sky_ir_temp_std
• Temperature, Sky Infra-Red(sky_ir_temp)

NSA/SKYRAD/C2 - NIP Frost or Ice

Frost or ice likely obstructed the NIP as short_direct_normal values were near zero for 
the affected time periods. These times correspond to mornings before OPS has the 
opportunity to clean the instruments. Clear days at Atqusuk are rare and the NIP instrument can 
very well be ice covered and it won't be apparent in the data.  In this case the clear days 
and overnight icing made the icing issue very apparent.

• inst_direct_normal

• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• short_direct_normal_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)