Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Schuemann, J.*; McNamara, A. L.*; Warmenhoven, J. W.*; Henthorn, N. T.*; Kirkby, K.*; Merchant, M. J.*; Ingram, S.*; Paganetti, H.*; Held, K. D.*; Ramos-Mendez, J.*; et al.
Radiation Research, 191(1), p.76 - 93, 2019/01
Times Cited Count：48 Percentile：94.44(Biology)We propose a new Standard DNA Damage (SDD) data format to unify the interface between the simulation of damage induction in DNA and the biological modelling of DNA repair processes, and introduce the effect of the environment (molecular oxygen or other compounds) as a flexible parameter. Such a standard greatly facilitates inter-model comparisons, providing an ideal environment to tease out model assumptions and identify persistent, underlying mechanisms. Through inter-model comparisons, this unified standard has the potential to greatly advance our understanding of the underlying mechanisms of radiation-induced DNA damage and the resulting observable biological effects when radiation parameters and/or environmental conditions change.
Katata, Genki; Nagai, Haruyasu; Zhang, L.*; Held, A.*; Ser
a, D.*; Klemm, O.*
Progress in Nuclear Science and Technology (Internet), 2, p.530 - 537, 2011/10
In order to investigate the transport of radioactive materials we have developed a one-dimensional numerical model that predicts the transfer of water, heat, and gaseous and particulate matters in atmosphere-soil-vegetation continuous system. The model calculates dry, wet and fog deposition of gaseous and particulate matters onto vegetation, taken into account the dependency of plant species such as leaf shape and leaf surface area. As a result of performance tests of the model under various environmental conditions, the model predicted the observed temporal changes in heat, water and CO
fluxes over vegetative and non-vegetative surface, and temperature, water content, and CO concentration in the soil under the temperate and arid climate. The model also reproduced observational data of mass fluxes of fog water and atmospheric gases such as ozone and 
, and number flux of nano-sized aerosols over the vegetation.
Katata, Genki; Held, A.*; Klemm, O.*; Nagai, Haruyasu
no journal, ,
Dry deposition process in a sophisticated multi-layer atmosphere-soil-vegetation model named SOLVEG was developed. Turbulent transfers in momentum, heat, cloud (fog) liquid water, water vapor, and carbon dioxide are solved in the SOLVEG model. The model takes into account the processes strongly related to dry deposition on vegetation such as stomata opening/closing and solar radiation transfers within canopy layers, in addition to photosynthesis, transpiration, and respiration processes. In this study, new schemes for dry deposition of gas and particulate matter were implemented in the model. Preliminary calculations were compared with measurements of ozone and particle number fluxes over the coniferous forest. Further modifications of the model are needed to estimate comprehensive acid deposition on vegetation via dry, wet and cloud deposition. The improved SOLVEG model may provide reference estimations for dry deposition monitoring in East Asia using simpler dry deposition models.
Katata, Genki; Held, A.*
no journal, ,
A new scheme for dry deposition estimation of atmospheric particles (fog and aerosol) was developed based on a sophisticated multi-layer atmosphere-soil-vegetation model (SOLVEG). The SOLVEG solves turbulent transfers in momentum, heat, fog (cloud) liquid water, water vapor, and carbon dioxide (CO) between atmosphere and land surface. Comprehensive particle capture module by leaves via Brownian diffusion, interception, inertial impaction, and gravitational settlement was implemented. The module was tested through the comparison between calculations by model and direct measurements of particle number flux measured by eddy covariance method over the forest. Comparing with the widely used model, the SOLVEG predicted better measured flux. The results suggested that new particle formulation in the atmosphere via gas-to-particle conversion affected deposition flux of nanometer size particles.
Katata, Genki; Held, A.*; Nagai, Haruyasu; Klemm, O.*
no journal, ,
no abstracts in English
Katata, Genki; Held, A.*; Mauder, M.*
no journal, ,
The leaf wetness was monitored using electrical sensors directly clipped to living leaf surfaces of thin and broad-leaved grasses. The measurements were carried out at the pre-alpine grassland site in Germany from September 20 to November 8, 2013. Numerical simulations of a multi-layer atmosphere-SOiL-VEGetation model (SOLVEG) were carried out for analyzing the data. The model reproduced well the observed leaf wetness, surface fluxes and temperature, and soil temperature and moisture. In rain-free days, a typical diurnal cycle as a decrease and increase during the day- and night-time, respectively, was observed in leaf wetness data. The high wetness level was always monitored under rain, fog, and snowcover conditions. Leaf wetness was also often high in the early morning due to thawing of leaf surface water frozen during a cold night.
Held, A.*; Katata, Genki
no journal, ,
Leaf surface wetness is an important factor in meteorological, agricultural, and environmental studies of plant-atmosphere exchange processes. Here, we present leaf wetness measurements using electrical sensors clipped directly to Norway spruce needles, and deposition estimates of inorganic ions to Norway spruce needles determined by a leaf-washing technique. The measurements were carried out at the Waldstein ecosystem research site of the University of Bayreuth. Leaf surface wetness was compared with relative humidity and wind speed, two key meteorological controls of leaf surface wetness. Finally, a trial calculation of the multi-layer atmosphere-soil-vegetation model SOLVEG was compared with the observed data. Overall, leaf surface wetness affects diverse phenomena such as vegetation-atmosphere water exchange or deposition fluxes to vegetation surfaces, which must be further explored in interdisciplinary research projects.
