Ozonsimulationen mit ICON für die Verbesserung von UV-Vorhersagen

Ozon (O3) in der Stratosph&#228;re absorbiert die biologisch sch&#228;dliche ultraviolette Strahlung der Sonne (den gr&#246;&#223;ten Teil der UV-B-Strahlung) und verhindert, dass sie die Erdoberfl&#228;che erreicht. Die energiereiche UV-Strahlung kann das genetische Material in den Zellen von Pflanzen und Tieren, sowie von Menschen zerst&#246;ren. Ohne die stratosph&#228;rische Ozonschicht w&#228;re das Leben auf der Erde, wie wir es kennen, nicht m&#246;glich. Der Deutsche Wetterdienst (DWD) stellt UV-Indexkarten zur Verf&#252;gung, um die Bev&#246;lkerung 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. In diesem Projekt wird in Zusammenarbeit mit dem DWD ein selbstkonsistentes System entwickelt, um UV-Indexkarten vollst&#228;ndig mittels ICON zu generieren. Zu diesem Zweck wird ein linearisiertes Ozonschema (LINOZ) [3] f&#252;r t&#228;gliche Ozonvorhersagen optimiert. Dies geschieht als Erweiterung der ICON-ART Struktur [4] [5] (ART: Aerosols and Reactive Trace gases). F&#252;r die Berechnung von UV-Strahlungsfl&#252;ssen und -indizes wurde ein Strahlungstransportmodell f&#252;r Sonnenstrahlung (Cloud-J) [6] implementiert und angepasst. Da das gesamte System als effiziente L&#246;sung f&#252;r UV-Indexvorhersagen dem DWD zur Verf&#252;gung gestellt werden soll, wird besonders Wert auf eine umfassende Funktionalit&#228;t bei sehr geringem Rechenaufwand gelegt. Ein wichtiger Teil der Arbeit ist daher auch die Validierung und Optimierung der Verfahren und Abl&#228;ufe, um zuverl&#228;ssige und qualitativ hochwertige Vorhersagen zu erstellen. Wir pr&#228;sentieren erste Ergebnisse des von ICON-ART modellierten UV-Strahlungsflusses durch die Atmosph&#228;re auf globaler Skala und &#252;ber ausgew&#228;hlten Gebieten, dessen tageszeitliche Variation, sowie den Einfluss von Wolken auf die UV-Intensit&#228;t. Anmerkung: Dieses Projekt wird durch den Deutschen Wetterdienst im Rahmen der Extramuralen Forschung mit folgender Nummer gef&#246;rdert: 4819EMF03. Referenzen: [1]&#160; https://kunden.dwd.de/uvi/index.jsp [2]&#160;&#160; Z&#228;ngl, 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) [3]&#160;&#160; 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) [4] &#160;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) [5]&#160; Schr&#246;ter, 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) [6]&#160; Prather, M.J., Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c. Geosci. Model Dev., 8(8), 2587-2595 (2015)

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Prognostic Ozone for ICON: Enabling UV Forecasts

10.5194/egusphere-egu21-8783 ◽

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

Stratospheric Ozone (O3) absorbs biologically harmful solar ultraviolet radiation (most of the UV&#8209;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.As part of its work the German Weather Service (DWD) provides UV index maps to warn the population in Germany of excessive UV exposure [[1]]. For this purpose, global ICON data, external ozone data and an external UV model is used.This study aims to create a self-consistent framework to generate UV index maps entirely from the non-hydrostatic global modelling system ICON [[2]]. For this purpose, a linearized ozone scheme (LINOZ) [[3]] will be optimized and the forecast functionality of ICON-ART [[4]][[5]] (ICOsahedral Non-hydrostatic &#8211; 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) [[6]] 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.&#160;&#160;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.<div> <div> [[1]] https://kunden.dwd.de/uvi/index.jsp </div> <div> [[2]] Z&#228;ngl, 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 </div> <div> [[3]] 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 </div> <div> [[4]] 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 </div> <div> [[5]] Schr&#246;ter, 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 </div> <div> [[6]] 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 </div> </div>

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ICON-ART 1.0 – a new online-coupled model system from the global to regional scale

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-567-2015 ◽

2015 ◽

Vol 8 (1) ◽

pp. 567-614

Author(s):

D. Rieger ◽

M. Bangert ◽

I. Bischoff-Gauss ◽

J. Förstner ◽

K. Lundgren ◽

...

Keyword(s):

Trace Gases ◽

Regional Scale ◽

Coupled Model ◽

Model System ◽

Emission Flux ◽

Monodisperse Particles ◽

Meteorological Model ◽

Model Studies ◽

Simulated Distribution ◽

Reactive Trace Gases

Abstract. We present the first stage of a new online-coupled global to regional scale modelling framework for the simulation of the spatiotemporal evolution of aerosols and trace gases. The underlying meteorological model is the new nonhydrostatic model system ICON (ICOsahedral Nonhydrostatic) which allows a local grid refinement with two-way interactions between the grids. We develop the extension ART (Aerosol and Reactive Trace gases) with the goal to simulate interactions between trace substances and the state of the atmosphere. Within this paper, we present the basic equations and give an overview of the physical parameterizations as well as numerical methods we use. First applications of the new model system for trace gases, monodisperse particles and polydisperse particles are shown. The simulated distribution of two very short-lived substances, Bromoform (CHBr3) and Dibrommethane (CH2Br2) reflecting the fast upward transport shows a good agreement with observations and previous model studies. Also, the shape of the simulated tropical profiles is well reproduced. As an example for the treatment of monodisperse particles we present the simulated ash plume of the Eyjafjallajökull eruption in April 2010. Here, a novel approach for the source function is applied. The pattern of the simulated distribution of volcanic ash particles shows an agreement with previous studies. As an example for the treatment of a polydisperse aerosol, where number densities and mass concentrations are accounted for, we simulated the annual emissions of sea salt. We obtain a total emission flux of 26.0 Pg yr−1 and an emission flux of particles with diameter less than 10 μm of 7.36 Pg yr−1.

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International symposium on numerical weather forecasting Oslo, March 11–16, 1963

Tellus ◽

10.3402/tellusa.v15i3.8843 ◽

1963 ◽

Vol 15 (3) ◽

pp. 284-286 ◽

Cited By ~ 1

Author(s):

George W. Platzman

Keyword(s):

International Symposium ◽

Weather Forecasting ◽

Numerical Weather ◽

Numerical Weather Forecasting

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Estimating Water Vapor Using Signals from Microwave Links below 25 GHz

Remote Sensing ◽

10.3390/rs13081409 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1409

Author(s):

Kun Song ◽

Xichuan Liu ◽

Taichang Gao ◽

Peng Zhang

Keyword(s):

Water Vapor ◽

Weather Forecasting ◽

Water Cycle ◽

Correlation Coefficients ◽

Support Vector ◽

Vapor Density ◽

Measurement Resolution ◽

Sensing Model ◽

Numerical Weather Forecasting ◽

Mean Square Errors

Water vapor is a key element in both the greenhouse effect and the water cycle. However, water vapor has not been well studied due to the limitations of conventional monitoring instruments. Recently, estimating rain rate by the rain-induced attenuation of commercial microwave links (MLs) has been proven to be a feasible method. Similar to rainfall, water vapor also attenuates the energy of MLs. Thus, MLs also have the potential of estimating water vapor. This study proposes a method to estimate water vapor density by using the received signal level (RSL) of MLs at 15, 18, and 23 GHz, which is the first attempt to estimate water vapor by MLs below 20 GHz. This method trains a sensing model with prior RSL data and water vapor density by the support vector machine, and the model can directly estimate the water vapor density from the RSLs without preprocessing. The results show that the measurement resolution of the proposed method is less than 1 g/m3. The correlation coefficients between automatic weather stations and MLs range from 0.72 to 0.81, and the root mean square errors range from 1.57 to 2.31 g/m3. With the large availability of signal measurements from communications operators, this method has the potential of providing refined data on water vapor density, which can contribute to research on the atmospheric boundary layer and numerical weather forecasting.

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Influence of the aerosol solar extinction on photochemistry during the 2010 Russian wildfires episode

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-10983-2015 ◽

2015 ◽

Vol 15 (19) ◽

pp. 10983-10998 ◽

Cited By ~ 9

Author(s):

J. C. Péré ◽

B. Bessagnet ◽

V. Pont ◽

M. Mallet ◽

F. Minvielle

Keyword(s):

Transport Model ◽

Regional Scale ◽

Model Performance ◽

Surface Concentration ◽

Near Surface ◽

Aerosol Mass ◽

Aerosol Mass Concentration ◽

Air Quality Measurements ◽

Photolysis Rates ◽

Optical Module

Abstract. In this work, impact of aerosol solar extinction on the photochemistry over eastern Europe during the 2010 wildfires episode is discussed for the period from 5 to 12 August 2010, which coincides to the peak of fire activity. The methodology is based on an online coupling between the chemistry-transport model CHIMERE (extended by an aerosol optical module) and the radiative transfer code TUV. Results of simulations indicate an important influence of the aerosol solar extinction, in terms of intensity and spatial extent, with a reduction of the photolysis rates of NO2 and O3 up to 50 % (in daytime average) along the aerosol plume transport. At a regional scale, these changes in photolysis rates lead to a 3–15 % increase in the NO2 daytime concentration and to an ozone reduction near the surface of 1–12 %. The ozone reduction is shown to occur over the entire boundary layer, where aerosols are located. Also, the total aerosol mass concentration (PM10) is shown to be decreased by 1–2 %, on average during the studied period, caused by a reduced formation of secondary aerosols such as sulfates and secondary organics (4–10 %) when aerosol impact on photolysis rates is included. In terms of model performance, comparisons of simulations with air quality measurements at Moscow indicate that an explicit representation of aerosols interaction with photolysis rates tend to improve the estimation of the near-surface concentration of ozone and nitrogen dioxide as well as the formation of inorganic aerosol species such as ammonium, nitrates and sulfates.

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Abundance and Sources of Atmospheric Halocarbons in the Eastern Mediterranean

10.5194/acp-2017-451 ◽

2017 ◽

Cited By ~ 2

Author(s):

Fabian Schoenenberger ◽

Stephan Henne ◽

Matthias Hill ◽

Martin K. Vollmer ◽

Giorgos Kouvarakis ◽

...

Keyword(s):

Western Europe ◽

Atmospheric Transport ◽

Eastern Mediterranean ◽

Stratospheric Ozone ◽

Regional Scale ◽

Top Down ◽

Inversion Domain ◽

Hfc 134A ◽

Wide Range ◽

Hfc 152A

Abstract. A wide range of anthropogenic halocarbons is released to the atmosphere, contributing to stratospheric ozone depletion and global warming. Using measurements of atmospheric abundances for the estimation of halocarbon emissions on the global and regional scale has become an important top-down tool for emission validation in the recent past, but many populated and developing areas of the world are only poorly covered by the existing atmospheric halocarbon measurement network. Here we present six months of continuous halocarbon observations from Finokalia on the island of Crete in the Eastern Mediterranean. The gases measured are the hydrofluorocarbons (HFCs), HFC-134a (CH2FCF3), HFC-125 (CHF2CF3), HFC-152a (CH3CHF2) and HFC-143a (CH3CF3), and the hydrochlorofluorocarbons (HCFCs), HCFC-22 (CHClF2) and HCFC-142b (CH3CClF2). The Eastern Mediterranean is home to 250 million inhabitants, consisting of a number of developed and developing countries, for which different emission regulations exist under the Kyoto and Montreal Protocols. Regional emissions of halocarbons were estimated with Lagrangian atmospheric transport simulations and a Bayesian inverse modelling system, using measurements at Finokalia in conjunction with those from Advanced Global Atmospheric Gases Experiment (AGAGE) sites at Mace Head (Ireland), Jungfraujoch (Switzerland) and Monte Cimone (Italy). Measured peak mole fractions at Finokalia showed generally smaller amplitudes for HFCs than at the European AGAGE sites, except periodic peaks of HFC-152a, indicating strong upwind sources. Higher peak mole fractions were observed for HCFCs, suggesting continued emissions from nearby developing regions such as Egypt and the Middle East. For 2013, the Eastern Mediterranean inverse emission estimates for the four analysed HFCs and the two HCFCs were 14.7 (6.7–23.3) Tg CO2eq yr-1 and 9.7 (4.3–15.7) Tg CO2eq yr-1, respectively. These emissions contributed 17.3 % (7.9–27.4 %) and 53 % (23.5–86%) to the total inversion domain, which covers the Eastern Mediterranean as well as Central and Western Europe. Greek bottom-up HFC emissions reported to the UNFCCC were much smaller than our top-down estimates, whereas for Turkey our estimates agreed with UNFCCC-reported values for HFC-125 and HFC-143a, but were much and slightly smaller for HFC-134a and HFC-152a, respectively. Sensitivity estimates suggest an improvement of the a posteriori emission estimates, i.e. a reduction of the uncertainties by 40–80 %, compared to an inversion using only the existing Central European AGAGE observations.

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Near real-time air quality forecasts using the NASA GEOS model

10.5194/egusphere-egu21-13587 ◽

2021 ◽

Author(s):

K. Emma Knowland ◽

Christoph Keller ◽

Krzysztof Wargan ◽

Brad Weir ◽

Pamela Wales ◽

...

Keyword(s):

Machine Learning ◽

Air Quality ◽

Real Time ◽

Weather Forecasting ◽

Atmospheric Composition ◽

Machine Learning Techniques ◽

Learning Techniques ◽

Wide Range ◽

Reactive Trace Gases ◽

Assimilation System

NASA's Global Modeling and Assimilation Office (GMAO) produces high-resolution global forecasts for weather, aerosols, and air quality. The NASA Global Earth Observing System (GEOS) model has been expanded to provide global near-real-time 5-day forecasts of atmospheric composition at unprecedented horizontal resolution of 0.25 degrees (~25 km). This composition forecast system (GEOS-CF) combines the operational GEOS weather forecasting model with the state-of-the-science GEOS-Chem chemistry module (version 12) to provide detailed analysis of a wide range of air pollutants such as ozone, carbon monoxide, nitrogen oxides, and fine particulate matter (PM2.5). Satellite observations are assimilated into the system for improved representation of weather and smoke. The assimilation system is being expanded to include chemically reactive trace gases. We discuss current capabilities of the GEOS Constituent Data Assimilation System (CoDAS) to improve atmospheric composition modeling and possible future directions, notably incorporating new observations (TROPOMI, geostationary satellites) and machine learning techniques. We show how machine learning techniques can be used to correct for sub-grid-scale variability, which further improves model estimates at a given observation site.

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On Coastal Ocean Systems, Coupled Model Architectures, Products and Services: Morphing from Observations to Operations and Applications

Marine Technology Society Journal ◽

10.4031/002533207787442268 ◽

2007 ◽

Vol 41 (1) ◽

pp. 44-52

Author(s):

L.J. Pietrafesa ◽

E. B. Buckley ◽

M. Peng ◽

S. Bao ◽

H. Liu ◽

...

Keyword(s):

Weather Forecasting ◽

Coupled Model ◽

Coastal Ocean ◽

Federal Agencies ◽

Coastal Zones ◽

Societal Needs ◽

Prediction Systems ◽

Ocean Observing ◽

Regional Effort ◽

Observing Systems

The national build-up of “coastal ocean observing systems” (COOSs) to establish the coastal observing component of the national component of the Integrated Ocean Observing System (IOOS) network must be well organized and must acknowledge, understand and address the needs of the principal clients, the federal, and in some cases state as well, agencies that provide financial support if it is to have substantive value. The funds being spent in support of COOS should be invested in pursuit of the establishment of the National Backbone (NB) that is needed: to greatly improve atmospheric, oceanic and coastal “weather” forecasting, broadly defined; for ecosystem management; and to document climate variability and change in coastal zones. However, this process has not occurred in a well conceived, orderly, well integrated manner due to historical and cultural bases and because of local priorities. A sub-regional effort that is designed to meet federal agency needs and mission responsibilities with an emphasis on meeting societal needs is presented by way of example to show that university and industry partners with federal agencies have an important role to play in the future of building out ocean and coastal observing and prediction systems and networks.

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North African vegetation-precipitation feedback in early and mid-Holocene climate simulations with CCSM3-DGVM

Climate of the Past Discussions ◽

10.5194/cpd-10-2055-2014 ◽

2014 ◽

Vol 10 (3) ◽

pp. 2055-2086 ◽

Cited By ~ 1

Author(s):

R. Rachmayani ◽

M. Prange ◽

M. Schulz

Keyword(s):

Regional Scale ◽

West African Monsoon ◽

Coupled Model ◽

Summer Precipitation ◽

Summer Rainfall ◽

Precipitation Anomaly ◽

Multiple Equilibrium ◽

North African ◽

African Region ◽

Sahel Region

Abstract. The present study analyses the sign, strength and working mechanism of the vegetation-precipitation feedback over North Africa in middle (6 ka BP) and early Holocene (9 ka BP) simulations using the comprehensive coupled climate-vegetation model CCSM3-DGVM. The coupled model simulates enhanced summer rainfall and a northward migration of the West African monsoon trough along with an expansion of the vegetation cover for the early and middle Holocene compared to pre-industrial. It is shown that dynamic vegetation enhances the orbitally triggered summer precipitation anomaly by approximately 20% in the Sahara/Sahel region (10° N–25° N, 20° W–30° E) in both the early and mid-Holocene experiments compared to their fixed-vegetation counterparts. The primary vegetation-rainfall feedback identified here operates through surface latent heat flux anomalies by canopy evaporation and transpiration and their effect on the mid-tropospheric African Easterly Jet, whereas the effects of vegetation changes on surface albedo and local water recycling play a negligible role. Even though CCSM3-DGVM simulates a positive vegetation-precipitation feedback in the North African region, this feedback is not strong enough to produce multiple equilibrium climate-ecosystem states on a regional scale.

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Mechanical stability indicators derived from detailed snow cover simulations

10.5194/egusphere-egu21-1341 ◽

2021 ◽

Author(s):

Léo Viallon-Galinier ◽

Pascal Hagenmuller ◽

Nicolas Eckert ◽

Benjamin Reuter

Keyword(s):

Mechanical Properties ◽

Snow Cover ◽

Mechanical Stability ◽

Weather Forecasting ◽

Large Data ◽

Failure Initiation ◽

Avalanche Hazard ◽

Snow Stratigraphy ◽

Numerical Weather Forecasting ◽

Numerical Tools

The use of numerical modeling of the snow cover in support of avalanche hazard forecasting has been increasing in the last decade. Besides field observations and numerical weather forecasting, these numerical tools provide information otherwise unavailable on the present and future state of the snow cover. In order to provide useful input for avalanche hazard assessment, different mechanical stability indicators are typically computed from simulated snow stratigraphy. Such indicators condense the wealth of information produced by snow cover models, especially when dealing with large data (e.g., large domains, high spatial resolution, ensemble forecasting). Here, we provide an overview of such indicators. Mechanical stability indicators can be classified in two types i.e., whether they are solely based on mechanical rules or whether they include additional expert rules. These indicators span different mechanical processes involved in avalanche release: failure initiation and crack propagation, for instance. The indicators rely on mechanical properties of each layer. We discuss parameterizations of mechanical properties and the associated technical implementation details. We show simplified examples of snow stratigraphy to illustrate the benefit of different stability indicators in typical situations. There is no perfect indicator to describe the instability for any situation. All indicators are sensitive to the snow cover modeling assumptions and the computation of mechanical properties and hence, require some tuning before operational use. In practice, a combination of indicators should be considered to capture the variety of avalanche situations.

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