Prognostic Ozone for ICON: Enabling UV Forecasts

2021 ◽  
Author(s):  
Simon Weber ◽  
Roland Ruhnke ◽  
Peter Braesicke ◽  
Christian Scharun
Keyword(s):  
Uv Radiation ◽  
Radiation Flux ◽  
Stratospheric Ozone ◽  
Regional Scale ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Human Beings ◽  
Geophysical Research ◽  
Uv Index ◽  
Index Maps

<p>Stratospheric Ozone (O<sub>3</sub>) absorbs biologically harmful solar ultraviolet radiation (most of the UV‑B radiation) and keeps it from reaching the surface. Such UV radiation is destructive of genetic cellular material in plants and animals, as well as human beings. Without the ozone layer, life on the surface of the Earth would not be possible as we know it.</p><p>As part of its work the German Weather Service (DWD) provides UV index maps to warn the population in Germany of excessive UV exposure <sup>[[1]]</sup>. For this purpose, global ICON data, external ozone data and an external UV model is used.</p><p>This study aims to create a self-consistent framework to generate UV index maps entirely from the non-hydrostatic global modelling system ICON <sup>[[2]]</sup>. For this purpose, a linearized ozone scheme (LINOZ) <sup>[[3]] </sup>will be optimized and the forecast functionality of ICON-ART <sup>[[4]][[5]]</sup> (ICOsahedral Non-hydrostatic – Aerosols and Reactive Trace gases) will be extended. For the derivation of UV radiation fluxes and indices a radiative transfer model for solar radiation (Cloud-J) <sup>[[6]]</sup> shall be implemented and extended. Since the entire framework is to be used at the DWD during ongoing operations, a functionality with very low computational effort is required.  </p><p>Here we present the first results of the UV radiation flux through the atmosphere and its diurnal variation. Furthermore, the influence of clouds on the UV radiation flux is considered.</p><div><br><div> <p><sup>[[1]]</sup> https://kunden.dwd.de/uvi/index.jsp</p> </div> <div> <p><sup>[[2]]</sup> Zängl, G., et al. (2014), The ICON (ICOsahedral Non-hydrostatic) modelling framework of DWD MPI-M: Description of the non-hydrostatic dynamical core. Q.J.R. Meteorol. Soc., doi:10.1002/qj.2378</p> </div> <div> <p><sup>[[3]]</sup> McLinden, C. A., et al. (2000), Stratospheric ozone in 3-D models: A simple chemistry and the cross-tropopause flux, Journal of Geophysical Research: Atmospheres, doi:10.1029/2000JD900124</p> </div> <div> <p><sup>[[4]]</sup> Rieger, D., et al. (2015), ICON-ART - A new online-coupled model system from the global to regional scale, Geosci. Model Dev., doi:10.5194/gmd-8-1659-2015</p> </div> <div> <p><sup>[[5]]</sup> Schröter, et al. (2018), ICON-ART 2.1: a flexible tracer framework and its application for composition studies in numerical weather forecasting and climate simulations. Geosci. Model Dev., doi:10.5194/gmd-11-4043-2018</p> </div> <div> <p><sup>[[6]]</sup> Prather, M.J. (2015), Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c. Geosci. Model Dev., doi:10.5194/gmd-8-2587-2015</p> </div> </div>

scholarly journals The Combined Effect of Ozone and Aerosols on Erythemal Irradiance in an Extremely Low Ozone Event during May 2020

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 145
Author(s):  
Ioannis-Panagiotis Raptis ◽  
Kostas Eleftheratos ◽  
Stelios Kazadzis ◽  
Panagiotis Kosmopoulos ◽  
Kyriakoula Papachristopoulou ◽  
...  
Keyword(s):  
Spectral Region ◽  
Stratospheric Ozone ◽  
Saharan Dust ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Model Calculations ◽  
Uv Index ◽  
Uv Irradiance ◽  
Spectral Solar Irradiance

In this study we focus on measurements and modeled UV index in the region of Athens, Greece, during a low ozone event. During the period of 12–19 May 2020, total ozone column (TOC) showed extremely low values, 35–55 Dobson Units (up to 15%) decrease from the climatic mean (being lower than the −2σ). This condition favors the increase of UV erythemal irradiance, since stratospheric ozone is the most important attenuator at the UVB spectral region. Simultaneously, an intrusion of Saharan dust aerosols in the region has masked a large part of the low ozone effect on UV irradiance. In order to investigate the event, we have used spectral solar irradiance measurements from the Precision Solar Radiometer (PSR), TOC from the Brewer spectrophotometer, and Radiative Transfer Model (RTM) calculations. Model calculations of the UV Index (UVI) showed an increase of ~30% compared to the long-term normal UVI due to the low TOC while at the same time and for particular days, aerosols masked this effect by ~20%. The RTM has been used to investigate the response in the UV spectral region of these variations at different solar zenith angles (SZAs). Spectra simulated with the RTM have been compared to measured ones and an average difference of ~2% was found. The study points out the importance of accurate measurements or forecasts of both ozone and aerosols when deriving UVI under unusual low ozone–high aerosol conditions.

scholarly journals Clear sky UV simulations for the 21st century based on ozone and temperature projections from Chemistry-Climate Models

2009 ◽  
Vol 9 (4) ◽  
pp. 1165-1172 ◽  
Author(s):  
K. Tourpali ◽  
A. F. Bais ◽  
A. Kazantzidis ◽  
C. S. Zerefos ◽  
H. Akiyoshi ◽  
...  
Keyword(s):  
Uv Radiation ◽  
21St Century ◽  
Climate Models ◽  
Stratospheric Ozone ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Clear Sky ◽  
Tropospheric Aerosol ◽  
Surface Reflectivity ◽  
Local Noon

Abstract. We have estimated changes in surface solar ultraviolet (UV) radiation under cloud free conditions in the 21st century based on simulations of 11 coupled Chemistry-Climate Models (CCMs). The total ozone columns and vertical profiles of ozone and temperature projected from CCMs were used as input to a radiative transfer model in order to calculate the corresponding erythemal irradiance levels. Time series of monthly erythemal irradiance received at the surface during local noon are presented for the period 1960 to 2100. Starting from the first decade of the 21st century, the surface erythemal irradiance decreases globally as a result of the projected stratospheric ozone recovery at rates that are larger in the first half of the 21st century and smaller towards its end. This decreasing tendency varies with latitude, being more pronounced over areas where stratospheric ozone has been depleted the most after 1980. Between 2000 and 2100 surface erythemal irradiance is projected to decrease over midlatitudes by 5 to 15%, while at the southern high latitudes the decrease is twice as much. In this study we have not included effects from changes in cloudiness, surface reflectivity and tropospheric aerosol loading, which will likely be affected in the future due to climate change. Consequently, over some areas the actual changes in future UV radiation may be different depending on the evolution of these parameters.

Ozonsimulationen mit ICON für die Verbesserung von UV-Vorhersagen

2021 ◽  
Author(s):  
Simon Weber ◽  
Roland Ruhnke ◽  
Christian Scharun ◽  
Axel Seifert ◽  
Peter Braesicke
Keyword(s):  
Weather Forecasting ◽  
Stratospheric Ozone ◽  
Regional Scale ◽  
Coupled Model ◽  
Geophysical Research ◽  
Uv Index ◽  
Modelling Framework ◽  
Photolysis Rates ◽  
Numerical Weather Forecasting ◽  
Reactive Trace Gases

<p class="Default">Ozon (O<sub>3</sub>) in der Stratosphäre absorbiert die biologisch schädliche ultraviolette Strahlung der Sonne (den größten Teil der UV-B-Strahlung) und verhindert, dass sie die Erdoberfläche erreicht. Die energiereiche UV-Strahlung kann das genetische Material in den Zellen von Pflanzen und Tieren, sowie von Menschen zerstören. Ohne die stratosphärische Ozonschicht wäre das Leben auf der Erde, wie wir es kennen, nicht möglich.</p> <p class="Default">Der Deutsche Wetterdienst (DWD) stellt UV-Indexkarten zur Verfügung, um die Bevölkerung bezgl. hoher UV-Belastungen zu informieren und zu warnen [1]. Dazu werden Daten aus dem golobalen Vorhersagemodell ICON (ICOsahedral Non-hydrostatic model) [2], externe Ozondaten und ein eigenes UV-Modell verwendet, um eine Vorhersage des UV-Index zu erstellen, der z.B. auf der DWD-Webseite als Vorhersage visualisiert wird.</p> <p class="Default">In diesem Projekt wird in Zusammenarbeit mit dem DWD ein selbstkonsistentes System entwickelt, um UV-Indexkarten vollständig mittels ICON zu generieren. Zu diesem Zweck wird ein linearisiertes Ozonschema (LINOZ) [3] für tägliche Ozonvorhersagen optimiert. Dies geschieht als Erweiterung der ICON-ART Struktur [4] [5] (ART: Aerosols and Reactive Trace gases). Für die Berechnung von UV-Strahlungsflüssen und -indizes wurde ein Strahlungstransportmodell für Sonnenstrahlung (Cloud-J) [6] implementiert und angepasst. Da das gesamte System als effiziente Lösung für UV-Indexvorhersagen dem DWD zur Verfügung gestellt werden soll, wird besonders Wert auf eine umfassende Funktionalität bei sehr geringem Rechenaufwand gelegt. Ein wichtiger Teil der Arbeit ist daher auch die Validierung und Optimierung der Verfahren und Abläufe, um zuverlässige und qualitativ hochwertige Vorhersagen zu erstellen.</p> <p class="Default">Wir präsentieren erste Ergebnisse des von ICON-ART modellierten UV-Strahlungsflusses durch die Atmosphäre auf globaler Skala und über ausgewählten Gebieten, dessen tageszeitliche Variation, sowie den Einfluss von Wolken auf die UV-Intensität.</p> <p><strong>Anmerkung:</strong></p> <p>Dieses Projekt wird durch den Deutschen Wetterdienst im Rahmen der Extramuralen Forschung mit folgender Nummer gefördert: 4819EMF03.</p> <p><strong>Referenzen:</strong></p> <p>[1]  https://kunden.dwd.de/uvi/index.jsp</p> <p>[2]   Zängl, G., et al., The ICON (ICOsahedral Non-hydrostatic) modelling framework of DWD MPI-M: Description of the non-hydrostatic dynamical core. Q.J.R. Meteorol. Soc., 141(687), 563-579 (2014)</p> <p>[3]   McLinden, C. A., et al., Stratospheric ozone in 3-D models: A simple chemistry and the cross-tropopause flux, Journal of Geophysical Research: Atmospheres, 105(D11), 14653-14665 (2000)</p> <p>[4]  Rieger, D., et al., ICON-ART - A new online-coupled model system from the global to regional scale, Geosci. Model Dev., 8(6), 1659-1676 (2015)</p> <p>[5]  Schröter, et al., ICON-ART 2.1: a flexible tracer framework and its application for composition studies in numerical weather forecasting and climate simulations. Geosci. Model Dev., 11(10), 4043-4068 (2018)</p> <p>[6]  Prather, M.J., Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c. Geosci. Model Dev., 8(8), 2587-2595 (2015)</p>

scholarly journals Extensive reduction of surface UV radiation since 1750 in world's populated regions

2009 ◽  
Vol 9 (20) ◽  
pp. 7737-7751 ◽  
Author(s):  
M. M. Kvalevåg ◽  
G. Myhre ◽  
C. E. Lund Myhre
Keyword(s):  
Uv Radiation ◽  
Correlation Coefficients ◽  
Ultra Violet ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Polar Regions ◽  
Ultra Violet Radiation ◽  
Wide Range ◽  
Extensive Surface ◽  
Year 2000

Abstract. Human activity influences a wide range of components that affect the surface UV radiation levels, among them ozone at high latitudes. We calculate the effect of human-induced changes in the surface erythemally weighted ultra-violet radiation (UV-E) since 1750. We compare results from a radiative transfer model to surface UV-E radiation for year 2000 derived by satellite observations (from Total Ozone Mapping Spectroradiometer) and to ground based measurements at 14 sites. The model correlates well with the observations; the correlation coefficients are 0.97 and 0.98 for satellite and ground based measurements, respectively. In addition to the effect of changes in ozone, we also investigate the effect of changes in SO2, NO2, the direct and indirect effects of aerosols, albedo changes and aviation-induced contrails and cirrus. The results show an increase of surface UV-E in polar regions, most strongly in the Southern Hemisphere. Furthermore, our study also shows an extensive surface UV-E reduction over most land areas; a reduction up to 20% since 1750 is found in some industrialized regions. This reduction in UV-E over the industrial period is particularly large in highly populated regions.

scholarly journals Influence of Leaf Specular Reflection on Canopy Radiative Regime Using an Improved Version of the Stochastic Radiative Transfer Model

2018 ◽  
Vol 10 (10) ◽  
pp. 1632 ◽  
Author(s):  
Bin Yang ◽  
Yuri Knyazikhin ◽  
Donghui Xie ◽  
Haimeng Zhao ◽  
Junqiang Zhang ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Flux Density ◽  
Vegetation Index ◽  
Radiation Flux ◽  
Specular Reflection ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Remotely Sensed Data ◽  
Wide Range ◽  
Radiative Regime

Interpreting remotely-sensed data requires realistic, but simple, models of radiative transfer that occurs within a vegetation canopy. In this paper, an improved version of the stochastic radiative transfer model (SRTM) is proposed by assuming that all photons that have not been specularly reflected enter the leaf interior. The contribution of leaf specular reflection is considered by modifying leaf scattering phase function using Fresnel reflectance. The canopy bidirectional reflectance factor (BRF) estimated from this model is evaluated through comparisons with field-measured maize BRF. The result shows that accounting for leaf specular reflection can provide better performance than that when leaf specular reflection is neglected over a wide range of view zenith angles. The improved version of the SRTM is further adopted to investigate the influence of leaf specular reflection on the canopy radiative regime, with emphases on vertical profiles of mean radiation flux density, canopy absorptance, BRF, and normalized difference vegetation index (NDVI). It is demonstrated that accounting for leaf specular reflection can increase leaf albedo, which consequently increases canopy mean upward/downward mean radiation flux density and canopy nadir BRF and decreases canopy absorptance and canopy nadir NDVI when leaf angles are spherically distributed. The influence is greater for downward/upward radiation flux densities and canopy nadir BRF than that for canopy absorptance and NDVI. The results provide knowledge of leaf specular reflection and canopy radiative regime, and are helpful for forward reflectance simulations and backward inversions. Moreover, polarization measurements are suggested for studies of leaf specular reflection, as leaf specular reflection is closely related to the canopy polarization.

scholarly journals Using a Parameterization of a Radiative Transfer Model to Build High-Resolution Maps of Typical Clear-Sky UV Index in Catalonia, Spain

2005 ◽  
Vol 44 (6) ◽  
pp. 789-803 ◽  
Author(s):  
Jordi Badosa ◽  
Josep-Abel González ◽  
Josep Calbó ◽  
Michiel van Weele ◽  
Richard L. McKenzie
Keyword(s):  
High Resolution ◽  
Radiative Transfer ◽  
Zenith Angle ◽  
Solar Zenith Angle ◽  
Absolute Error ◽  
Single Scattering ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Uv Index ◽  
Wide Range

Abstract To perform a climatic analysis of the annual UV index (UVI) variations in Catalonia, Spain (northeast of the Iberian Peninsula), a new simple parameterization scheme is presented based on a multilayer radiative transfer model. The parameterization performs fast UVI calculations for a wide range of cloudless and snow-free situations and can be applied anywhere. The following parameters are considered: solar zenith angle, total ozone column, altitude, aerosol optical depth, and single-scattering albedo. A sensitivity analysis is presented to justify this choice with special attention to aerosol information. Comparisons with the base model show good agreement, most of all for the most common cases, giving an absolute error within ±0.2 in the UVI for a wide range of cases considered. Two tests are done to show the performance of the parameterization against UVI measurements. One uses data from a high-quality spectroradiometer from Lauder, New Zealand [45.04°S, 169.684°E, 370 m above mean sea level (MSL)], where there is a low presence of aerosols. The other uses data from a Robertson–Berger-type meter from Girona, Spain (41.97°N, 2.82°E, 100 m MSL), where there is more aerosol load and where it has been possible to study the effect of aerosol information on the model versus measurement comparison. The parameterization is applied to a climatic analysis of the annual UVI variation in Catalonia, showing the contributions of solar zenith angle, ozone, and aerosols. High-resolution seasonal maps of typical UV index values in Catalonia are presented.

scholarly journals Cloud effect on the Ultraviolet index

2021 ◽  
Author(s):  
Lucie Pokorná ◽  
Helena Tomanová
Keyword(s):  
Uv Radiation ◽  
Human Body ◽  
Stratospheric Ozone ◽  
Global Radiation ◽  
Uv Index ◽  
Middle Latitudes ◽  
Increased Risk ◽  
Modification Factor ◽  
Cloud Effect ◽  
High Level

<p>Ultraviolet (UV) radiation is essential for many biological processes even its intensity near the surface is weak in comparison with visible and infrared sun radiation. Plants, animals and humans adopted to common UV radiation intensity. However higher doses pose an increased risk for all organisms. The UV index (UVI) defined in early 90s is recently used to express possible harm to the human body.</p><p>The UVI is computed from the spectral intensity of UV–B radiation. Its magnitude is thus related to sun elevation, cloud cover, stratospheric ozone concentration, altitude and air pollution. Important factor is also snow cover which increases the UVI due to high reflectivity. The UVI usually attains values between 0 and 9 in middle latitudes; the higher value of the UVI indicates a higher risk of the human body harm. The highest values are generally reached in sunny days around the noon in June and July in mid-latitudes. The cloudiness usually decreases the UVI and the Cloud modification factor defined for the UV-B radiation reduction is usually applied for the UVI forecast.</p><p>The aim of the contribution is to quantify effect of clouds on the UVI and revise the values of the CMF for the UVI. Different types of clouds, the base height and cloud structure are considered. The study is based on station measurement of the UVI, global radiation and sun duration in 10 minutes intervals from four stations in the Czechia during the period 2011–2017. The parameters of clouds were extracted from the SYNOP reports from the nearest stations. The results show a weak effect of high- level clouds on the UVI (decrease of 15 %) even under cover 8/8. The mid- and low-level clouds reduce the UVI with factor 0,7 to 0,35 according to its amount. However, clouds with vertical evolution (cumulus and cumulonimbus) cause in specific cases even increase of the UVI. Complete table of cloud effect on the UVI for the sun elevation between 35° and 50° will be introduced in presentation.</p>

scholarly journals Global Clear-Sky Aerosol Speciated Direct Radiative Effects over 40 Years (1980–2019)

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1254
Author(s):  
Marios-Bruno Korras-Carraca ◽  
Antonis Gkikas ◽  
Christos Matsoukas ◽  
Nikolaos Hatzianastassiou
Keyword(s):  
Global Climate ◽  
Regional Scale ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Radiative Effect ◽  
Clear Sky ◽  
Order Of Magnitude ◽  
Carbon Aerosols ◽  
Aerosol Types

We assess the 40-year climatological clear-sky global direct radiative effect (DRE) of five main aerosol types using the MERRA-2 reanalysis and a spectral radiative transfer model (FORTH). The study takes advantage of aerosol-speciated, spectrally and vertically resolved optical properties over the period 1980–2019, to accurately determine the aerosol DREs, emphasizing the attribution of the total DREs to each aerosol type. The results show that aerosols radiatively cool the Earth’s surface and heat its atmosphere by 7.56 and 2.35 Wm−2, respectively, overall cooling the planet by 5.21 Wm−2, partly counterbalancing the anthropogenic greenhouse global warming during 1980–2019. These DRE values differ significantly in terms of magnitude, and even sign, among the aerosol types (sulfate and black carbon aerosols cool and heat the planet by 1.88 and 0.19 Wm−2, respectively), the hemispheres (larger NH than SH values), the surface cover type (larger land than ocean values) or the seasons (larger values in local spring and summer), while considerable inter-decadal changes are evident. These DRE differences are even larger by up to an order of magnitude on a regional scale, highlighting the important role of the aerosol direct radiative effect for local and global climate.

USDA UV-B Monitoring and Research Program

2020 ◽  
Author(s):  
Wei Gao ◽  
George Janson ◽  
Chelsea Corr ◽  
Maosi Chen
Keyword(s):  
Uv Radiation ◽  
Research Program ◽  
Stratospheric Ozone ◽  
Temporal Trends ◽  
Plant Litter ◽  
Primary Data ◽  
Potential Threat ◽  
Uv Index ◽  
Average Value ◽  
The U.S

<p>Solar Ultraviolet (UV) radiation has significant impacts on human health (e.g., skin cancer) and the environment (e.g., agricultural production and plant litter decomposition). Reductions in UV-absorbing stratospheric ozone resulting from climate change and the anthropogenic emission of ozone depleting substances raised concerns regarding future levels of surface UV radiation. Responding to this potential threat, the U.S. Department of Agriculture (USDA) investigated the need for UV monitoring across the U.S. in 1991 and established the UV-B Monitoring and Research Program (UVMRP) headquartered in Natural Resource Ecology Laboratory at Colorado State University later in 1992. The UVMRP is tasked with providing information on the geographical distribution and temporal trends of UV radiation and studying the effects of UV radiation on a wealth of agricultural interests including crop plants, rangelands, and forests. The UVMRP currently consists of 37 climatological monitoring sites and 4 research sites, most of which are distributed across the U.S., with an additional site in Canada and another in New Zealand. Collectively, these sites encompass 20 ecoregions. Each UVMRP site is equipped with four primary irradiance instruments including the: 1) UV MultiFilter Rotating Shadowband Radiometer (UV-MFRSR), 2) visible MFRSR, 3) UVB-1 broadband meter, and 4) Photosynthetically Active Radiation (PAR) sensor. The UV-MFRSR measures total horizontal, diffuse horizontal, and direct normal irradiance at nominal 300, 305, 311, 317, 325, 332, and 368 nm at 2 nm FWHM (full-width half-maximum). The VIS-MFRSR measures the same three irradiance components at nominal SiC, 415, 500, 610, 665, 860, and 940 nm at 10 nm FWHM. PAR and UVB-1 sensors measure broadband irradiances over the 400-700 nm and 280-320 nm ranges, respectively. All these observations are sampled every 15 or 20 seconds and stored as an average value every three minutes. The raw data measurements are processed following a variety of Quality Control (QC) and calibration procedures to ensure the quality of the data. The primary data products (i.e., irradiances) as well as the derived products (e.g., UV Index and weighted daily/hourly sums) are distributed through the UVMRP website (http://uvb.nrel.colostate.edu). In this poster, we present a UV climatology study that explores long-term trends of erythemal irradiance at eight locations across the U.S. derived from 8-11 years of UVMRP measurements.</p>

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