The NDACC Spectral UV Instrument Working Group announces several publications in 2018 of interest to the NDACC community

Ralf Zuber et al. on the validation of a new array spectroradiometer:  A measurement system consisting of two array spectroradiometers, a UV-BTS and a VIS-BTS was set up, to achieve a wavelength range from 200 nm to 1050 nm. This system has been compared with the NDACC travelling UV spectroradiometer, which is a double monochromator-based device that complies to the NDACC specifications at a measurement campaign for spectral global irradiance with the aim to validate an array spectroradiometer as well with the stated NDACC specifications. Although the new array devices do not fully match the NDACC specifications they show good performance which qualify them as candidates for NDACC.

Zuber R., Ribnitzky M., Tobar M., Lange K., Kutscher D., Schrempf M., Niedzwiedz A., Seckmeyer G.: Global spectral irradiance array spectroradiometer validation according to WMO, Atmos. Meas. Tech., 2018, accepted

Gunther Seckmeyer et al. on the impact of solar radiation on human health: The impact of solar radiation on human health in different spectral ranges of solar radiation (UV, Visible and Infrared) was described. For each spectral range the respective biological and medical effects were considered. Both negative (skin cancer, skin aging, erythema) and positive effects (e.g. Vitamin D) of solar radiation on human skin was considered. Moreover, some aspects on the measurement of spectral solar radiation were discussed and novel instruments for measuring spectral radiance were introduced.

Seckmeyer G., Lagos Rivas L., Gaetani C., Heinzel J.W., Schrempf M.: Biologische und medizinische Wirkungen solarer Strahlung (Biological and medical effects of solar radiation), in Promet, Heft 100, Strahlungsbilanzen, chapter 13, Deutscher Wetterdienst (DWD), 2018

Gunther Seckmeyer et al. on the radiation properties, laws and transfer:  In this publication the most important radiative quantities, important radiation laws for the radiative energy budget, the radiative transfer equation and some solutions are presented. Moreover, the microscopical scattering and absorption properties were summarized in a special chapter.

Seckmeyer G., Wendisch M., Macke A.: Strahlungsgrößen, -gesetze und –übertragung, (Radiation properties, radiation laws and radiation transfer), in Promet, Heft 100, Strahlungsbilanzen, chapter 1, Deutscher Wetterdienst (DWD), 2018

Gunther Seckmeyer et al. on the solar UV exposure on the human body: Shading in the natural and artificial environment of humans can limit the availability of solar radiation quite drastically. For vitamin D-weighted exposure the direct sun plays a minor role only. Instead, sky radiance has been found to be the dominant factor for human solar UV exposure. To determine the vitamin D3–weighted exposure the solar spectral radiance must be known from all directions. Within a city reductions of typically more than 50% compared to unshaded areas was found. In addition it was also found that the reduction of exposure was not simply proportional to the shaded fraction of the sky. The actual reduction depends on the location strongly.

Seckmeyer G., Schrempf M.: How much shade is healthy?, May 2018

Ralf Zuber et al. on the total ozone column retrieval by an array spectroradiometer:  A compact array spectroradiometer that enables precise and robust measurements of solar UV spectral direct irradiance is presented. It was shown that this instrument can accurately retrieve total ozone column (TOC). In addition, the internal straylight, often the limiting factor for measurements in the UV spectral range and TOC, was physically reduced so that no other stray light reduction method is necessary.

Zuber R., Sperfeld P., Riechelmann S., Nevas S., Sildoja M., Seckmeyer G.: Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range, Atmos. Meas. Tech., 11, 2477-2484,, 2018

Gunther Seckmeyer et al. on the UV exposure differences in southern and northern Hemisphere:  UV exposure, which is the main source for a sufficient level of vitamin D in the human body, is found to be up to a factor of 7 lower in Northern Germany (52° N) in the winter months compared to UV levels in the central region of New Zealand’s South Island (45°S). On the other hand Europe show a high variability due to cloudiness differences between the stations and between different years, but they also show that the differences are not restricted to individual sites and may characterize a northern versus southern hemisphere contrast.

Seckmeyer G., Mustert C., Schrempf M., McKenzie R.L., Liley B.J., Kotkamp M., Bais A.F., Gillotay D., Slaper H., Siani A-M., Smedley A.R.D., Webb A.: Why is it so hard to gain enough Vitamin D by solar exposure in the European winter?, Met.Zeitschrift, DOI 10.1127/metz/2018/0855, 2018