A multi-site, year-round turbulence microstructure atlas for the deep perialpine Lake Garda

AbstractA multi-site, year-round dataset comprising a total of 606 high-resolution turbulence microstructure profiles of shear and temperature gradient in the upper 100 m depth is made available for Lake Garda (Italy). Concurrent meteorological data were measured from the fieldwork boat at the location of the turbulence measurements. During the fieldwork campaign (March 2017-June 2018), four different sites were sampled on a monthly basis, following a standardized protocol in terms of time-of-day and locations of the measurements. Additional monitoring activity included a 24-h campaign and sampling at other sites. Turbulence quantities were estimated, quality-checked, and merged with water quality and meteorological data to produce a unique turbulence atlas for a lake. The dataset is open to a wide range of possible applications, including research on the variability of turbulent mixing across seasons and sites (demersal vs pelagic zones) and driven by different factors (lake-valley breezes vs buoyancy-driven convection), validation of hydrodynamic lake models, as well as technical studies on the use of shear and temperature microstructure sensors.

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Using Satellite Data for CBRN (Chemical, Biological, Radiological, and Nuclear) Threat Detection, Monitoring, and Modelling

Surveys in Geophysics ◽

10.1007/s10712-021-09637-5 ◽

2021 ◽

Author(s):

Gary Sutlieff ◽

Lucy Berthoud ◽

Mark Stinchcombe

Keyword(s):

Satellite Data ◽

Meteorological Data ◽

Atmospheric Composition ◽

Chemical Detection ◽

List Type ◽

Data Types ◽

Wide Range ◽

Future Technologies ◽

The Impact ◽

Near Future

Abstract CBRN (Chemical, Biological, Radiological, and Nuclear) threats are becoming more prevalent, as more entities gain access to modern weapons and industrial technologies and chemicals. This has produced a need for improvements to modelling, detection, and monitoring of these events. While there are currently no dedicated satellites for CBRN purposes, there are a wide range of possibilities for satellite data to contribute to this field, from atmospheric composition and chemical detection to cloud cover, land mapping, and surface property measurements. This study looks at currently available satellite data, including meteorological data such as wind and cloud profiles, surface properties like temperature and humidity, chemical detection, and sounding. Results of this survey revealed several gaps in the available data, particularly concerning biological and radiological detection. The results also suggest that publicly available satellite data largely does not meet the requirements of spatial resolution, coverage, and latency that CBRN detection requires, outside of providing terrain use and building height data for constructing models. Lastly, the study evaluates upcoming instruments, platforms, and satellite technologies to gauge the impact these developments will have in the near future. Improvements in spatial and temporal resolution as well as latency are already becoming possible, and new instruments will fill in the gaps in detection by imaging a wider range of chemicals and other agents and by collecting new data types. This study shows that with developments coming within the next decade, satellites should begin to provide valuable augmentations to CBRN event detection and monitoring. Article Highlights There is a wide range of existing satellite data in fields that are of interest to CBRN detection and monitoring. The data is mostly of insufficient quality (resolution or latency) for the demanding requirements of CBRN modelling for incident control. Future technologies and platforms will improve resolution and latency, making satellite data more viable in the CBRN management field

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A Mobile Sensing System for UrbanPM2.5Monitoring with Adaptive Resolution

Journal of Sensors ◽

10.1155/2016/7901245 ◽

2016 ◽

Vol 2016 ◽

pp. 1-15 ◽

Cited By ~ 3

Author(s):

Hongjie Guo ◽

Guojun Dai ◽

Jin Fan ◽

Yifan Wu ◽

Fangyao Shen ◽

...

Keyword(s):

Air Quality ◽

Meteorological Data ◽

Computational Cost ◽

Estimation Method ◽

Mobile Sensing ◽

Prototype System ◽

Adaptive Grids ◽

Sensing System ◽

Adaptive Resolution ◽

Wide Range

This paper develops a mobile sensing system, the first system used in adaptive resolution urban air quality monitoring. In this system, we employ several taxis as sensor carries to collect originalPM2.5data and collect a variety of datasets, including meteorological data, traffic status data, and geographical data in the city. This paper also presents a novel method AG-PCEM (Adaptive Grid-Probabilistic Concentration Estimation Method) to infer thePM2.5concentration for undetected grids using dynamic adaptive grids. We gradually collect the measurements throughout a year using a prototype system in Xiasha District of Hangzhou City, China. Experimental data has verified that the proposed system can achieve good performance in terms of computational cost and accuracy. The computational cost of AG-PCEM is reduced by about 40.2% compared with a static grid method PCEM under the condition of reaching the close accuracy, and the accuracy of AG-PCEM is far superior as widely used artificial neural network (ANN) and Gaussian process (GP), enhanced by 38.8% and 14.6%, respectively. The system can be expanded to wide-range air quality monitor by adjusting the initial grid resolution, and our findings can tell citizens actual air quality and help official management find pollution sources.

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DWD Geoportal – Converging open data, metadata and documentation in a user-friendly way

10.5194/ems2021-423 ◽

2021 ◽

Author(s):

Björn Reetz ◽

Hella Riede ◽

Dirk Fuchs ◽

Renate Hagedorn

Keyword(s):

Service Providers ◽

Meteorological Data ◽

Open Data ◽

Time Of Day ◽

Free Access ◽

Free Text ◽

Free Text Search ◽

Easy Integration ◽

Access To Data ◽

User Friendly

Since 2017, Open Data has been a part of the DWD data distribution strategy. Starting with a small selection of meteorological products, the number of available datasets has grown continuously over the last years. Since the start, users can access datasets anonymously via the website https://opendata.dwd.de to download file-based meteorological products. Free access and the variety of products has been welcomed by the general public as well as private met service providers. The more datasets are provided in a directory structure, however, the more tedious it is to find and select among all available data. Also, metadata and documentation were available, but on separate public websites. This turned out to be an issue, especially for new users of DWD's open data.To help users explore the available datasets as well as to quickly decide on their suitability for a certain use case, the Open Data team at DWD is developing a geoportal. It enables free-text search along with combined access to data, metadata, and description along with interactive previews via OGC WMS.Cloud technology is a suitable way forward for hosting the geoportal along with the data in its operational state. Benefits are expected for the easy integration of rich APIs with the geoportal, and the flexible and fast deployment and scaling of optional or prototypical services such as WMS-based previews. Flexibility is also mandatory to respond to fluctuating user demands, depending on time of day and critical weather situations, which is supported by containerization. The growing overall volume of meteorological data at DWD may mandate to allow customers to bring their code to the data&#160;&#8211; for on-demand processing including slicing and interpolation &#8211;&#160; instead of transferring files to every customer. Shared cloud instances are the ideal interface for this purpose.The contribution will outline a protoype version of the new geoportal and discuss further steps for launching it to the public.

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Comparative verification in complex topography

10.5194/ems2021-246 ◽

2021 ◽

Author(s):

Jonas Bhend ◽

Jean-Christophe Orain ◽

Vera Schönenberger ◽

Christoph Spirig ◽

Lionel Moret ◽

...

Keyword(s):

Weather Forecasting ◽

Absolute Error ◽

Time Of Day ◽

Probabilistic Forecasts ◽

Wide Range ◽

Direct Model ◽

Forecasting System ◽

The Mean ◽

Update Frequency ◽

Core Activity

Verification is a core activity in weather forecasting. Insights from verification are used for monitoring, for reporting, to support and motivate development of the forecasting system, and to allow users to maximize forecast value. Due to the broad range of applications for which verification provides valuable input, the range of questions one would like to answer can be very large. Static analyses and summary verification results are often insufficient to cover this broad range. To this end, we developed an interactive verification platform at MeteoSwiss that allows users to inspect verification results from a wide range of angles to find answers to their specific questions.We present the technical setup to achieve a flexible yet performant interactive platform and two prototype applications: monitoring of direct model output from operational NWP systems and understanding of the capabilities and limitations of our pre-operational postprocessing. We present two innovations that illustrate the user-oriented approach to comparative verification adopted as part of the platform. To facilitate the comparison of a broad range of forecasts issued with varying update frequency, we rely on the concept of time of verification to collocate the most recent available forecasts at the time of day at which the forecasts are used. In addition, we offer a matrix selection to more flexibly select forecast sources and scores for comparison. Doing so, we can for example compare the mean absolute error (MAE) for deterministic forecasts to the MAE and continuous ranked probability scores of probabilistic forecasts to illustrate the benefit of using probabilistic forecasts.

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Goldilocks mixing in oceanic shear-induced turbulent overturns

Journal of Fluid Mechanics ◽

10.1017/jfm.2021.740 ◽

2021 ◽

Vol 928 ◽

Author(s):

A. Mashayek ◽

C.P. Caulfield ◽

M.H. Alford

Keyword(s):

Ocean Circulation ◽

Turbulent Mixing ◽

Intermediate Phase ◽

Turbulent Flux ◽

Geographical Location ◽

Small Scale ◽

Supporting Evidence ◽

Stratified Turbulence ◽

Wide Range ◽

Variable Flux

We present a new, simple and physically motivated parameterization, based on the ratio of Thorpe and Ozmidov scales, for the irreversible turbulent flux coefficient $\varGamma _{\mathcal {M}}= {\mathcal {M}}/\epsilon$ , i.e. the ratio of the irreversible rate ${\mathcal {M}}$ at which the background potential energy increases in a stratified flow due to macroscopic motions to the dissipation rate of turbulent kinetic energy $\epsilon$ . Our parameterization covers all three key phases (crucially, in time) of a shear-induced stratified turbulence life cycle: the initial, ‘hot’ growing phase, the intermediate energetically forced phase and the final ‘cold’ fossilization decaying phase. Covering all three phases allows us to highlight the importance of the intermediate one, to which we refer as the ‘Goldilocks’ phase due to its apparently optimal (and so neither too hot nor too cold, but just right) balance, in which energy transfer from background shear to the turbulent mixing is most efficient. The value of $\varGamma _{\mathcal {M}}$ is close to 1/3 during this phase, which we demonstrate appears to be related to an adjustment towards a critical or marginal Richardson number for sustained turbulence ${\sim }0.2\text {--}0.25$ . Importantly, although buoyancy effects are still significant at leading order for the turbulent dynamics during this intermediate phase, the marginal balance in the flow ensures that the turbulent mixing of the (density) scalar is nevertheless effectively ‘locked’ to the turbulent mixing of momentum. We present supporting evidence for our parameterization through comparison with six oceanographic datasets that span various turbulence generation regimes and a wide range of geographical location and depth. Using these observations, we highlight the significance of parameterizing an inherently variable flux coefficient for capturing the turbulent flux associated with rare energetic, yet fundamentally shear-driven (and so not strongly stratified) overturns that make a disproportionate contribution to the total mixing. We also highlight the importance of representation of young turbulent patches in the parameterization for connecting the small scale physics to larger scale applications of mixing such as ocean circulation and tracer budgets. Shear-induced turbulence is therefore central to irreversible mixing in the world's oceans, apparently even close to the seafloor, and it is critically important to appreciate the inherent time dependence and evolution of mixing events: history matters to mixing.

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Parallelization of the Lattice Boltzmann Method in Simulating Buoyancy-Driven Convection Heat Transfer

Heat Transfer, Volume 2 ◽

10.1115/imece2004-61871 ◽

2004 ◽

Author(s):

Anoosheh Niavarani-Kheirier ◽

Masoud Darbandi ◽

Gerry E. Schneider

Keyword(s):

Lattice Boltzmann Method ◽

Lattice Boltzmann ◽

Message Passing ◽

Large Scale ◽

Message Passing Interface ◽

Parallel Machines ◽

Convection Heat Transfer ◽

Wide Range ◽

Buoyancy Driven Convection ◽

Boltzmann Method

The main objective of the current work is to utilize Lattice Boltzmann Method (LBM) for simulating buoyancy-driven flow considering the hybrid thermal lattice Boltzmann equation (HTLBE). After deriving the required formulations, they are validated against a wide range of Rayleigh numbers in buoyancy-driven square cavity problem. The performance of the method is investigated on parallel machines using Message Passing Interface (MPI) library and implementing domain decomposition technique to solve problems with large order of computations. The achieved results show that the code is highly efficient to solve large scale problems with excellent speedup.

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Soil, snow, weather, and sub-surface storage data from a mountain catchment in the rain–snow transition zone

Earth System Science Data Discussions ◽

10.5194/essdd-6-811-2013 ◽

2013 ◽

Vol 6 (2) ◽

pp. 811-835 ◽

Cited By ~ 1

Author(s):

P. R. Kormos ◽

D. Marks ◽

C. J. Williams ◽

H. P. Marshall ◽

P. Aishlin ◽

...

Keyword(s):

Soil Moisture ◽

Transition Zone ◽

Soil Texture ◽

Soil Depth ◽

Meteorological Data ◽

Dew Point ◽

Soil Profiles ◽

Data Set ◽

Hydrologic Condition ◽

Wide Range

Abstract. A comprehensive hydroclimatic data set is presented for the 2011 water year to improve understanding of hydrologic processes in the rain-snow transition zone. This type of dataset is extremely rare in scientific literature because of the quality and quantity of soil depth, soil texture, soil moisture, and soil temperature data. Standard meteorological and snow cover data for the entire 2011 water year are included, which include several rain-on-snow events. Surface soil textures and soil depths from 57 points are presented as well as soil texture profiles from 14 points. Meteorological data include continuous hourly shielded, unshielded, and wind corrected precipitation, wind speed, air temperature, relative humidity, dew point temperature, and incoming solar and thermal radiation data. Sub-surface data included are hourly soil moisture data from multiple depths from 7 soil profiles within the catchment, and soil temperatures from multiple depths from 2 soil profiles. Hydrologic response data include hourly stream discharge from the catchment outlet weir, continuous snow depths from one location, intermittent snow depths from 5 locations, and snow depth and density data from ten weekly snow surveys. Though it represents only a single water year, the presentation of both above and below ground hydrologic condition makes it one of the most detailed and complete hydro-climatic datasets from the climatically sensitive rain-snow transition zone for a wide range of modeling and descriptive studies. Data are available at doi:10.1594/PANGAEA.819837.

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Remote sensing of ecosystem light use efficiency with MODIS-based PRI

Biogeosciences ◽

10.5194/bg-8-189-2011 ◽

2011 ◽

Vol 8 (1) ◽

pp. 189-202 ◽

Cited By ~ 53

Author(s):

A. Goerner ◽

M. Reichstein ◽

E. Tomelleri ◽

N. Hanan ◽

S. Rambal ◽

...

Keyword(s):

Meteorological Data ◽

Vapour Pressure Deficit ◽

Ground Truth ◽

Light Use Efficiency ◽

Wide Range ◽

Evaluation Exercise ◽

Use Efficiency ◽

Study Sites ◽

Absorbed Photosynthetically Active Radiation

Abstract. Several studies sustained the possibility that a photochemical reflectance index (PRI) directly obtained from satellite data can be used as a proxy for ecosystem light use efficiency (LUE) in diagnostic models of gross primary productivity. This modelling approach would avoid the complications that are involved in using meteorological data as constraints for a fixed maximum LUE. However, no unifying model predicting LUE across climate zones and time based on MODIS PRI has been published to date. In this study, we evaluate the effectiveness with which MODIS-based PRI can be used to estimate ecosystem light use efficiency at study sites of different plant functional types and vegetation densities. Our objective is to examine if known limitations such as dependence on viewing and illumination geometry can be overcome and a single PRI-based model of LUE (i.e. based on the same reference band) can be applied under a wide range of conditions. Furthermore, we were interested in the effect of using different faPAR (fraction of absorbed photosynthetically active radiation) products on the in-situ LUE used as ground truth and thus on the whole evaluation exercise. We found that estimating LUE at site-level based on PRI reduces uncertainty compared to the approaches relying on a maximum LUE reduced by minimum temperature and vapour pressure deficit. Despite the advantages of using PRI to estimate LUE at site-level, we could not establish an universally applicable light use efficiency model based on MODIS PRI. Models that were optimised for a pool of data from several sites did not perform well.

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Cloud Inhomogeneity from MODIS

Journal of Climate ◽

10.1175/jcli3591.1 ◽

2005 ◽

Vol 18 (23) ◽

pp. 5110-5124 ◽

Cited By ~ 37

Author(s):

Lazaros Oreopoulos ◽

Robert F. Cahalan

Keyword(s):

Optical Thickness ◽

Large Scale ◽

Spatial Scales ◽

Temporal Variations ◽

Global Scale ◽

Time Of Day ◽

Wide Range ◽

Level 3 ◽

Inhomogeneity Parameter ◽

Moderate Resolution Imaging Spectroradiometer

Abstract Two full months (July 2003 and January 2004) of Moderate Resolution Imaging Spectroradiometer (MODIS) Atmosphere Level-3 data from the Terra and Aqua satellites are analyzed in order to characterize the horizontal variability of vertically integrated cloud optical thickness (“cloud inhomogeneity”) at global scales. The monthly climatology of cloud inhomogeneity is expressed in terms of standard parameters, initially calculated for each day of the month at spatial scales of 1° × 1° and subsequently averaged at monthly, zonal, and global scales. Geographical, diurnal, and seasonal changes of inhomogeneity parameters are examined separately for liquid and ice phases and separately over land and ocean. It is found that cloud inhomogeneity is overall weaker in summer than in winter. For liquid clouds, it is also consistently weaker for local morning than local afternoon and over land than ocean. Cloud inhomogeneity is comparable for liquid and ice clouds on a global scale, but with stronger spatial and temporal variations for the ice phase, and exhibits an average tendency to be weaker for near-overcast or overcast grid points of both phases. Depending on cloud phase, hemisphere, surface type, season, and time of day, hemispheric means of the inhomogeneity parameter ν (roughly the square of the ratio of optical thickness mean to standard deviation) have a wide range of ∼1.7 to 4, while for the inhomogeneity parameter χ (the ratio of the logarithmic to linear mean) the range is from ∼0.65 to 0.8. The results demonstrate that the MODIS Level-3 dataset is suitable for studying various aspects of cloud inhomogeneity and may prove invaluable for validating future cloud schemes in large-scale models capable of predicting subgrid variability.

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Hydraulic Resistance of Plants. II. Effects of Rooting Medium, and Time of Day, in Barley and Lupin

Functional Plant Biology ◽

10.1071/pp9840341 ◽

1984 ◽

Vol 11 (5) ◽

pp. 341 ◽

Cited By ~ 54

Author(s):

JB Passioura ◽

R Munns

Keyword(s):

Osmotic Pressure ◽

Hydraulic Resistance ◽

External Solution ◽

Time Of Day ◽

Pressure Chamber ◽

Sand Soil ◽

Rooting Medium ◽

Wide Range ◽

Flow Through ◽

The Difference

Barley and lupin plants were grown in pots designed to fit inside a pressure chamber. The pots contained sand, soil, or nutrient solution. Transpiration rates were varied over a wide range. At a given transpiration rate, Q, the balancing pressure, p, of a plant was determined; p is the pneumatic pressure that must be applied to the roots in the pressure chamber to have a cut in the xylem of the shoot on the verge of bleeding. The relation between p and Q, p(Q), was non-linear and hysteretic for solution- grown plants, but was remarkably linear for plants grown in sand or soil, i.e. the data for a given plant on a given occasion conformed closely to the equation p =po + rQ, where po and r were constants. Even though p(Q) was linear for the plants grown in sand or soil, po was often much larger than Δπ, the difference in osmotic pressure between the external solution and the xylem of the root, so that the apparent hydraulic resistance of the plants, i.e. (p-Δπ)/Q, depended strongly on Q. Furthermore, po changed diurnally and was typically 100-200 kPa higher in the afternoon than in the morning. These results are discussed in relation to the equations that are commonly used to describe water flow through plants. It is postulated that r represents the true hydraulic resistance of the plant, which is independent of Q in the plants grown in soil or sand but may vary diurnally, and that the discrepancy between po and Δπ represents either an additional and hitherto unrecognized difference in osmotic pressure across the membranes of the root that intercept the transpiration stream, or a pressure required to open valves through which the water has to pass, with the valves possibly being located in the plasmodesmata.

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