Narrowband filter radiometer for ground-based measurements of global ultraviolet solar irradiance and total ozone

Abstract. We demonstrate the use of a Monte Carlo model to estimate the uncertainties in total ozone column (TOC) derived from ground-based direct solar spectral irradiance measurements. The model estimates the effects of possible systematic spectral deviations in the solar irradiance spectra on the uncertainties in retrieved TOC. The model is tested with spectral data measured with three different spectroradiometers at an intercomparison campaign of the research project “Traceability for atmospheric total column ozone” at Izaña, Tenerife on 17 September 2016. The TOC values derived at local noon have expanded uncertainties of 1.3 % (3.6 DU) for a high-end scanning spectroradiometer, 1.5 % (4.4 DU) for a high-end array spectroradiometer, and 4.7 % (13.3 DU) for a roughly adopted instrument based on commercially available components and an array spectroradiometer when correlations are taken into account. When neglecting the effects of systematic spectral deviations, the uncertainties reduce by a factor of 3. The TOC results of all devices have good agreement with each other, within the uncertainties, and with the reference values of the order of 282 DU during the analysed day, measured with Brewer spectrophotometer #183.

Download Full-text

Angular responsivity of ground and space-based direct solar irradiance radiometers

Journal of Physics Conference Series ◽

10.1088/1742-6596/2149/1/012001 ◽

2022 ◽

Vol 2149 (1) ◽

pp. 012001

Author(s):

Gregor Hülsen ◽

Julian Gröbner ◽

Daniel Pfiffner ◽

Manfred Gyo ◽

Natalia Kouremeti ◽

...

Keyword(s):

Solar Irradiance ◽

Optical Axis ◽

Field Of View ◽

Angular Response ◽

Filter Radiometer ◽

Four Quadrant

Abstract The angular response setup of PMOD/WRC was modified to facilitate measurements of the narrow field of view of radiometers for direct solar irradiance. First, The pointing of the JTSIM-DARA radiometer was measured four times during its construction in the optic laboratory of PMOD/WRC. The final offset of the pointing before shipping relative to the optical axis, defined by a removable alignment cube, is 1.07° / 0.67° (β/γ-axis) for the four-quadrant sensor and 0.095°/-0.017° for the radiometer cavity A. Next to JTSIM-DARA the DARA for the occulter of the satellite Proba-3 was characterised at PMOD/WRC. First tests of the pointing have been carried out and the final pointing characterization will be carried out in summer 2021. Finally, the angular response setup was also used the angular responsivity of solar direct irradiance filter radiometers. The first test was carried out using Precision Filter Radiometer (PFR) F-064.

Download Full-text

Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range

10.5194/amt-2017-240 ◽

2017 ◽

Author(s):

Ralf Zuber ◽

Peter Sperfeld ◽

Stefan Riechelmann ◽

Saulius Nevas ◽

Meelis Sildoja ◽

...

Keyword(s):

Spectral Range ◽

Solar Irradiance ◽

Total Ozone ◽

Spectral Irradiance ◽

Stray Light ◽

Limiting Factor ◽

Total Ozone Column ◽

Reduction Methods ◽

Robust Measurements ◽

Ozone Column

Abstract. A compact array spectroradiometer technology that enables precise and robust measurements of UV spectral irradiance is presented. The spectroradiometer design allows various applications such as measurement of high-power UV lamps, risk assessment of sources and measurement of solar irradiance. We show that this technology can perform precise total ozone column (TOC) retrieval. The internal stray light, which is often the limiting factor for measurements in the UV spectral range and increases the uncertainty for TOC analysis significantly, is physically reduced so that no other stray light 15 reduction methods, such as mathematical corrections, are necessary. The instrument and its elaborate components have been extensively characterised at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. During an international total ozone measurement intercomparison at the Izaña observatory in Tenerife, the high-quality applicability of the instrument was verified with measurements of the direct solar irradiance and subsequent TOC evaluations based on the spectral data between 12 and 30 September 2016. The results showed deviations of less than 1.5 % to most other instruments in most 20 situations not exceeding 3 % compared to established TOC measurement systems such as Dobson or Brewer.

Download Full-text

UV Index and Total Ozone Column Climatology of Nepal Himalaya Using TOMS and OMI Data

Journal of Hydrology and Meteorology ◽

10.3126/jhm.v9i1.15581 ◽

2016 ◽

Vol 9 (1) ◽

pp. 45-59

Author(s):

R.R. Sharma ◽

B. Kjeldstad ◽

P.J. Espy

Keyword(s):

High Altitude ◽

Total Ozone ◽

Extreme Values ◽

Nepal Himalaya ◽

Uv Index ◽

Total Ozone Column ◽

Clear Sky ◽

Ground Measurement ◽

Filter Radiometer ◽

Ozone Column

Ultraviolet index (UVI) and Total Ozone Column (TOC) climatology of six stations of Nepal Himalaya using ground measurement, and OMI / TOMS satellite data is presented. The positive bias found in the OMI UV index from previous study is corrected empirically using a ratio factor using the clear sky coincident data of OMI and ground measurement from NILU UV multi-band filter radiometer (MBFR). UV index >3 in the winter months (e.g. December) and more than 9 during the summer months (May-August) are common in most of the stations. High altitude stations even have more extreme values (>11) during the summer months. Under some meteorological conditions, UV index often found more than 16 at the high altitude station (latitude 28o, altitude 2850m) during a clear sky day in the monsoon season. Diurnal and altitudinal variability is also highlighted. Monthly average TOC climatology from November 1978 to March 2012 using TOMS (Nimbus 7, Meteor3 and Earth Probe) and OMI is also presented. The ozone column data follows the annual cycle, minimum in November/December and maximum in April/May. In addition, slight negative trend of TOC is found in the data from 1978 to 2012.Journal of Hydrology and Meteorology, Vol. 9(1) 2015, p.45-59

Download Full-text

Total ozone column measurements using an ultraviolet multi-filter radiometer

International Journal of Remote Sensing ◽

10.1080/01431161.2015.1083631 ◽

2015 ◽

Vol 36 (17) ◽

pp. 4469-4482 ◽

Cited By ~ 1

Author(s):

P.I. Raptis ◽

S. Kazadzis ◽

K. Eleftheratos ◽

P. Kosmopoulos ◽

V. Amiridis ◽

...

Keyword(s):

Total Ozone ◽

Total Ozone Column ◽

Filter Radiometer ◽

Ozone Column

Download Full-text

Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range

Atmospheric Measurement Techniques ◽

10.5194/amt-11-2477-2018 ◽

2018 ◽

Vol 11 (4) ◽

pp. 2477-2484 ◽

Cited By ~ 3

Author(s):

Ralf Zuber ◽

Peter Sperfeld ◽

Stefan Riechelmann ◽

Saulius Nevas ◽

Meelis Sildoja ◽

...

Keyword(s):

Spectral Range ◽

Solar Irradiance ◽

Total Ozone ◽

Stray Light ◽

Limiting Factor ◽

Light Reduction ◽

Total Ozone Column ◽

Reduction Methods ◽

Robust Measurements ◽

Ozone Column

Abstract. A compact array spectroradiometer that enables precise and robust measurements of solar UV spectral direct irradiance is presented. We show that this instrument can retrieve total ozone column (TOC) accurately. The internal stray light, which is often the limiting factor for measurements in the UV spectral range and increases the uncertainty for TOC analysis, is physically reduced so that no other stray-light reduction methods, such as mathematical corrections, are necessary. The instrument has been extensively characterised at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. During an international total ozone measurement intercomparison at the Izaña Atmospheric Observatory in Tenerife, the high-quality applicability of the instrument was verified with measurements of the direct solar irradiance and subsequent TOC evaluations based on the spectral data measured between 12 and 30 September 2016. The results showed deviations of the TOC of less than 1.5 % from most other instruments in most situations and not exceeding 3 % from established TOC measurement systems such as Dobson or Brewer.

Download Full-text