Status of the De Aar BSRN Station South Africa - Isac-Cnr

Status of the De Aar BSRN Station
South Africa
South African Weather Service
Presented to:
The 13th BSRN Scientific Review and Workshop
Bologna, Italy
07-12 September 2014
Katlego Ncongwane
RES-GAW-08-12 September 2014. BSRN Scientific Meeting, Bologna Italy.
Outline
1. Historic overview of South Africa’s Solar Radiation Network
2. The De Aar BSRN station. The Old and the New
3. Future Outlook
Historical overview of radiation measurement in
South Africa
Historic Radiation Network
Prior to 1990
o Historic Network 1956-1991
o Kipp & Zonen CM2 & CM5 (Global and Diffuse Horizontal Irradiance) Network
o The network was well maintained calibrated as recommended
o Campbell –Stokes sunshine recorders
(20 stations in 1940, 117 in 1987, 69 in 1995 and now 42)
Roodeplaat
Pretoria
Nelspruit
Keetmanshoop
Alexanderbay
Upington
Bloemfontein
Since 1989
o
o
o
o
o
Start of the AWS network.
Licor pyranometer (global and diffuse)
1993 onwards UV Biometer network - Solar Light (PE, DNB, CT, PTA and CPT, De Aar)
Last WMO ISO calibration just prior to 2000 in Davos
Linke Cavity Radiometer and PMO6 the primary and secondary standards
very out dated operating functionality.
Durban
Windhoek
Cape Town
Cape Point
Grootfontein
Events leading to SA’s Involvement in the BSRN
1989: South Africa’s first involvement in an unofficial capacity
1990: First Workshop (Washington DC, USA 3-5 December 1990)
1991: Second Workshop (Davos, Switzerland, 6-8 August 1991)
1994: Third Workshop (Zurich, Switzerland, 12-16 September 1994)
1996: Fourth Workshop (Boulder, Co, USA, 12-16 August 1996)
De Aar BSRN Station
1996: BSRN Infrastructure development started in South Africa
1999: The De Aar Station operated as no 40 in the global network
1999 : De Aar BSRN station measured LW, Global, Direct and Diffuse)
2000: Data first submitted to the world database.
2004: Calibration in Davos
De Aar Side description
o Centrally locate in the Country
o Pristine atmosphere
o Semi-arid with relatively low rainfall
o Aerial appearance of land is uniform
o small town with low population and metropolitan
growth
o Max and Min Temperature vary from 0° in winter to
The Old De Aar BSRN Operated (1999-2007)
33° C in summer
o Likelihood of snow 1 out of 450 or 0.8 days per year
2008: Decline in human capital capacity within the weather service
(with the sudden passing of Danie Esterhuyse who managed
the De Aar BSRN).
Meta Data on the De Aar BSRN Station
Parameter
Type of Instrument and
method of
measurement
Direct solar radiation
Solar tracked pyrheliometer
continuously
Diffuse solar radiation
Solar tracker shaded and
ventilated pyranometer
continuously
Global solar radiation
Continuously exposed
ventilated pyranometer
continuously
Atmospheric long-wave
Solar shaded and ventilated
radiation
pyrgeometer continuously
Surface temperature,
Pressure sensor and
humidity and atmospheric Stevenson- screen based
pressure
temp-humidity probe.
Upper-air data
Balloon-tethered radiosonde.
Surface SYNOP data
Standard observations
Parameters monitored & method of measurement
Sampling frequency
Instrument
Precision checks
Kipp & Zonen
CH1
Kipp & Zonen
CM21
1 minute statistics, average, min, max and std.dev.
Yes
1 minute statistics, average, min, max and std.dev.
Yes
Kipp & Zonen
CM21
1 minute statistics, average, min, max and std.dev.
Yes
Eppley PIR
1 minute statistics, average, min, max and std.dev.
Yes
Standard SAWS 5 minute intervals (standard SAWS five-minute data)
instrumentation
No
Daily (10:00 UT)
Vaisala RS-80
radiosonde
Observer on site Hourly
No
No
Calibration service and procedure
Yes
Yes
Yes
For pyrheliometer- direct comparison between non-operational standard Eppley AHF cavity radiometer (traceable to WSG) and
operational pyrheliometers. For pyranometers – direct calculation of standard sensitivity values based upon the calibrated
pyrheliometer values.
Once to twice annually
To World Standard Radiation Group (WSG) at the World Radiation Centre in Davos, Switzerland.
January 2004
No independent systems audit done
N/A
Standard site operating procedures for instrumentation
Standard site operating procedures for sampling
Precision testing
Calibration procedure
Calibration frequency
Traceability of calibration standards
Date of last calibration
Date of last systems audit
Auditing laboratory
Data quality and storage
Parameter
Data period
Quality control Description of QC procedure
Data reporting format
Direct radiation
01/08/1999-2007
Yes
Diffuse radiation
01/08/1999-2007
Yes
Global Radiation
01/08/1999-2007
Yes
Long wave radiation
01/08/2000-2007
Yes
Monthly dataset in prescribed format
submitted directly to WRMC Zürich
Five minute data
01/08/1999-2007
No
Upper air data
01/11/1999-2007
No
Monthly dataset in prescribed format
submitted directly to WRMC Zürich
Monthly dataset in prescribed format
submitted directly to WRMC Zürich
SYNOP Data
01/11/1999-2007
No
a) Use latest sensitivity factor per instrument for final data; (b) Compare direct data with sunrise, Monthly dataset in prescribed format
sunset and local noon times per day; (c) Delete times of instrument cleaning (detected with submitted directly to WRMC Zürich
pyrheliometer pair) from dataset; (d) Compare global-direct-diffuse solar zenith angle relationship; (e) Monthly dataset in prescribed format
Compare global with Top of Atmosphere (TOA) radiation; (f) Compare long-wave with empirical submitted directly to WRMC Zürich
atmospheric emissivity based upon surface temperature; (g) Identify non-zero night data due to
thermal offsets, (h) Flag all anomalies in procedures (b) to (g).
Monthly dataset in prescribed format
submitted directly to WRMC Zürich
Monthly dataset in prescribed format
De Aar BSRN Station Reinstated
In operation since 09-10 April 2014
Old station 1999
New station 2014
SAWS Current Radiation Stations (PHASE I)
BSRN Station
+
Solar Radiation SOLYS stations
Instrumentation Specifications
Sensor
Kipp & Zonen Solys 2 Sun Tracker
Parameter
Track the sun
Stations
All stations
Kipp & Zonen CHP1 Pyrheliometer
Kipp & Zonen CHP11 (no 1 :Sun) Pyranometer
Kipp & Zonen CHP11 (no 2: Shadow) Pyranometer
Kipp & Zonen CHP21 (no 1 :Sun)Pyranometer
Kipp & Zonen CHP21 (no 1 :Shadow) Pyranometer
Kipp & Zonen CGR4 Pygeometer
Kipp & Zonen CUV-5
Kipp & Zonen UVS-AB-T
Barometer PTB110 Vaisala
RM Young Wind Sensor
Rotronic Temp and Humidity probe HC2-S3
Direct Normal Irradiance
Global Horizontal Irradiance
Diffuse Horizontal Irradiance
Global Horizontal Irradiance
Diffuse Horizontal Irradiance
Long-wave Irradiance
UV radiation (290-385nm)
UVA & UVB
Pressure
Wind
Humidity and Temperature
All stations
All stations except for De Aar
All stations except for De Aar
Only at De Aar
Only at De Aar
Only at De Aar
Only at Prieska
All stations except for Prieska
All stations
All stations
All stations
SAWS SOLYS STATIONS Phase I & II
o 7 solar radiation stations (including
the BSRN) currently in operation,
located at 4 of the 6 climatic zones.
o 6 more stations to be installed
before the end of the year 2014, in
total the network will consist of 12
SOLYS stations and 1 BSRN station
located in De Aar.
o Solar radiation activities is peaking
in South Africa with private stakeholders and universities operating
and managing their solar radiation
networks.
Data, station maintenance & real-time monitoring
o
o
o
Data is sampled at 1 second and averaged at 5 seconds, 1 minute, hourly and daily
intervals.
The De Aar and other radiation stations are cleaned twice a week in accordance to the
maintenance guidelines of solar radiation stations.
Stations are monitored through the Campbell Scientific RTMC pro (Real Time Monitoring &
Control) monitoring system.
Data from the New BSRN Station
Templ ref: PPT-ISO-colour.001 Doc Ref no:
Data from the New BSRN Station
Templ ref: PPT-ISO-colour.001 Doc Ref no:
Quality Control
o
The quality control protocol for the stations are based on Baseline Surface Radiation
Network (BSRN) standards of World Meteorological Organization (WMO).
1.Physically possible
2.Extremely rare
3.Across quantities
4.Comparison with a model
5.Eye check of time series plots
Templ ref: PPT-ISO-colour.001 Doc Ref no:
Future Outlook
o
South Africa keen to be an active member of the BSRN, and participate on the Working Groups
o
Partnership and collaboration with experience institutions to build capacity
The end
Thank you

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