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Feister U.,German Meteorological Service DWD | Meyer G.,German Social Accident Insurance Institution for Transport and Traffic | Laschewski G.,Center for Human Biometeorological Research | Boettcher C.,Free University of Berlin
Journal of Geophysical Research D: Atmospheres

The Personal ERythemal EXposure (PEREX) model for seafarers working on decks of vessels has been developed to be used for retrospective estimates of personal occupational erythemal exposure in dependence of work profile, time period, and sea route. Extremely high UV index values up to 22 and daily erythemal exposure up to 89 standard erythemal dose have been derived from ship-based measurements in tropical oceans. Worldwide climatological maps of daily solar erythemal exposure derived from 10 year (2004-2013) hourly grid point radiative transfer model calculations for both cloudless sky and cloudy sky serve as the database of PEREX. The PEREX database is compared with ship-based measurements taken along four routes of merchant vessels, continuous UV radiation measurements taken on the research vessel Meteor on its mainly tropical and subtropical routes for 2 years, daily cloudless-sky erythemal exposure derived from 10 min LibRadtran radiative transfer model calculations, and 2 years of satellite-based erythemal exposure data of the Ozone Monitoring Instrument on the Aura satellite along the ship routes. Systematic differences between PEREX model data, ship-based data, and satellite-based daily erythemal exposure for all-sky conditions are only 1 to 3%, while short-term variations of cloudiness result in standard deviations of differences around 30%. Measured ratios between cloudless-sky erythemal radiation at vertical to horizontal incidence decrease with decreasing solar zenith angle, while clouds flatten their diurnal course. Key Points Estimates of personal solar erythemal exposure Validation of model data Solar UV radiation on tropical oceans ©2015. American Geophysical Union. All Rights Reserved. Source

Scheidt J.,Hof University of Applied Sciences | Koppe C.,Center for Human Biometeorological Research | Rill S.,Hof University of Applied Sciences | Reinel D.,Hof University of Applied Sciences | And 2 more authors.
International Journal of Biometeorology

Many factors trigger migraine attacks. Weather is often reported to be one of the most common migraine triggers. However, there is little scientific evidence about the underlying mechanisms and causes. In our pilot study, we used smartphone apps and a web form to collect around 4,700 migraine messages in Germany between June 2011 and February 2012. Taking interdiurnal temperature changes as an indicator for changes in the prevailing meteorological conditions, our analyses were focused on the relationship between temperature changes and the frequency of occurrence of migraine attacks. Linear trends were fitted to the total number of migraine messages with respect to temperature changes. Statistical and systematic errors were estimated. Both increases and decreases in temperature lead to a significant increase in the number of migraine messages. A temperature increase (decrease) of 5 °C resulted in an increase of 19 ± 7 % (24 ± 8 %) in the number of migraine messages. © 2012 ISB. Source

Feister U.,German Meteorological Service DWD | Laschewski G.,Center for Human Biometeorological Research | Grewe R.-D.,German Meteorological Service DWD
Journal of Photochemistry and Photobiology B: Biology

While erythemal irradiance as a potentially damaging effect to the skin has been extensively studied and short-term forecasts have been issued to the public to reduce detrimental immediate and long-term effects such as sunburn and skin cancer by overexposure, beneficial effects to human health such as vitamin D3 production by UV radiation and melatonin suppression by blue visible light have attained more and more attention, though both of them have not become part of forecasting yet. Using 4 years of solar radiation data measured at the mid-latitude site Lindenberg (52°N), and forecast daily maximum UV index values, an overall good correspondence has been found. The data base of solar UV radiation and illuminance has also been used to analyze effects of clouds and aerosols on the effective irradiance. Optically thick clouds can strongly modify the ratios between erythemal and vitamin D 3 effective irradiance such that direct radiative transfer modeling of the latter in future UV forecasts should be preferably used. If parameterizations of vitamin D3 effective irradiance from erythemal irradiance are used instead, the optical cloud depth would have to be taken into account to avoid an overestimation of vitamin D3 with parameterizations neglecting cloud optical depth. Particular emphasis for the beneficial effects has been laid in our study on low exposure. Daily doses of solar irradiation for both vitamin D3 and melatonin suppression do not reach minimum threshold doses even with clear sky and unobstructed horizon during the winter months. © 2010 Elsevier B.V. All rights reserved. Source

Kaminski U.,Center for Human Biometeorological Research | Fricker M.,Center for Human Biometeorological Research | Dietze V.,Center for Human Biometeorological Research
Meteorologische Zeitschrift

Since 2009, the measurement of the background concentration of the fine particle fraction has been a part of the climate-monitoring program of the German Meteorological Service (DWD). These particles are of high health relevance as a critical air pollutant affecting processes like the scattering and absorption of solar radiation and influencing cloud formation and visibility. At 12 weather stations, the coarse (2.5 to 10 μm) and the fine particle fractions (PM2.5) are measured by means of passive and active samplers. First results are presented for the mass concentrations of coarse and fine particles as well as for the black carbon (BC) content and the concentration of certain inorganic ions of fine particles. There is not only a seasonal correlation between the fraction of fine and coarse particles, but also a correlation with the location (urban background or rural background).With the help of light microscopy, coarse particles can be differentiated for a geogenic (predominantly wind blown mineral and sea salt particles of natural origin and road abrasion) and for an anthropogenic opaque component (combustion residues, e.g. fly ash and non-exhaust vehicle emissions, e.g. abrasion particles of brakes and tires). Measuring the fine fraction and the coarse fraction separately instead of PM10 allows for a better source allocation and thus is a more appropriate method for the improvement of the air quality in, e. g. low emission zones. © by Gebrüder Borntraeger 2013. Source

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