scholarly journals Quantifying Near‐Surface Rock Strength on a Regional Scale From Hillslope Stability Models

2020 ◽  
Vol 125 (7) ◽  
Author(s):  
Kirk F. Townsend ◽  
Sean F. Gallen ◽  
Marin K. Clark
Keyword(s):  
Rock Strength ◽  
Regional Scale ◽  
Near Surface ◽  
Surface Rock ◽  
Hillslope Stability

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

2015 ◽  
Vol 15 (19) ◽  
pp. 10983-10998 ◽  
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.

Regional characterisation of soil properties by combining soil science and hyperspectral and thermal remote sensing: A technical overview of lab and field remote sensing methods

2021 ◽  
Author(s):  
Richard Mommertz ◽  
Lars Konen ◽  
Martin Schodlok
Keyword(s):  
Remote Sensing ◽  
Soil Properties ◽  
Regional Scale ◽  
Arable Land ◽  
Soil Mapping ◽  
Soil Science ◽  
Near Surface ◽  
Soil Parameter ◽  
The Impact ◽  
Parameter Retrieval

<p>Soil is one of the world’s most important natural resources for human livelihood as it provides food and clean water. Therefore, its preservation is of huge importance. For this purpose, a proficient regional database on soil properties is needed. The project “ReCharBo” (Regional Characterisation of Soil Properties) has the objective to combine remote sensing, geophysical and pedological methods to determine soil characteristics on a regional scale. Its aim is to characterise soils non-invasive, time and cost efficient and with a minimal number of soil samples to calibrate the measurements. Konen et al. (2021) give detailed information on the research concept and first field results in a presentation in the session “SSS10.3 Digital Soil Mapping and Assessment”. Hyperspectral remote sensing is a powerful and well known technique to characterise near surface soil properties. Depending on the sensor technology and the data quality, a wide variety of soil properties can be derived with remotely sensed data (Chabrillat et al. 2019, Stenberg et al. 2010). The project aims to investigate the effects of up and downscaling, namely which detail of information is preserved on a regional scale and how a change in scales affects the analysis algorithms and the possibility to retrieve valid soil parameter information. Thus, e.g. laboratory and field spectroscopy are applied to gain information of samples and fieldspots, respectively. Various UAV-based sensors, e.g. thermal & hyperspectral sensors, are applied to study soil properties of arable land in different study areas at field scale. Finally, airborne (helicopter) hyperspectral data will cover the regional scale. Additionally forthcoming spaceborne hyperspectral satellite data (e.g. Prisma, EnMAP, Sentinel-CHIME) are a promising outlook to gain detailed regional soil information. In this context it will be discussed how the multisensor data acquisition is best managed to optimise soil parameter retrieval. Sensor specific properties regarding time and date of acquisition as well as weather/atmospheric conditions are outlined. The presentation addresses and discusses the impact of a multisensor and multiscale remote sensing data collection regarding the results on soil parameter retrieval.</p><p> </p><p>References</p><p>Chabrillat, S., Ben-Dor, E. Cierniewski, J., Gomez, C., Schmid, T. & van Wesemael, B. (2019): Imaging Spectroscopy for Soil Mapping and Monitoring. Surveys in Geophysics 40:361–399. https://doi.org/10.1007/s10712-019-09524-0</p><p>Stenberg, B., Viscarra Rossel, R. A., Mounem Mouazen, A. & Wetterlind, J. (2010): Visible and Near Infrared Spectroscopy in Soil Science. In: Donald L. Sparks (editor): Advances in Agronomy. Vol. 107. Academic Press:163-215. http://dx.doi.org/10.1016/S0065-2113(10)07005-7</p>

scholarly journals Distributed snow and rock temperature modelling in steep rock walls using Alpine3D

2017 ◽  
Vol 11 (1) ◽  
pp. 585-607 ◽  
Author(s):  
Anna Haberkorn ◽  
Nander Wever ◽  
Martin Hoelzle ◽  
Marcia Phillips ◽  
Robert Kenner ◽  
...  
Keyword(s):  
Energy Balance ◽  
Snow Cover ◽  
Snow Depth ◽  
Spatial Scales ◽  
Swiss Alps ◽  
Balance Model ◽  
Near Surface ◽  
Surface Rock ◽  
Depth Data ◽  
Rock Temperature

Abstract. In this study we modelled the influence of the spatially and temporally heterogeneous snow cover on the surface energy balance and thus on rock temperatures in two rugged, steep rock walls on the Gemsstock ridge in the central Swiss Alps. The heterogeneous snow depth distribution in the rock walls was introduced to the distributed, process-based energy balance model Alpine3D with a precipitation scaling method based on snow depth data measured by terrestrial laser scanning. The influence of the snow cover on rock temperatures was investigated by comparing a snow-covered model scenario (precipitation input provided by precipitation scaling) with a snow-free (zero precipitation input) one. Model uncertainties are discussed and evaluated at both the point and spatial scales against 22 near-surface rock temperature measurements and high-resolution snow depth data from winter terrestrial laser scans.In the rough rock walls, the heterogeneously distributed snow cover was moderately well reproduced by Alpine3D with mean absolute errors ranging between 0.31 and 0.81 m. However, snow cover duration was reproduced well and, consequently, near-surface rock temperatures were modelled convincingly. Uncertainties in rock temperature modelling were found to be around 1.6 °C. Errors in snow cover modelling and hence in rock temperature simulations are explained by inadequate snow settlement due to linear precipitation scaling, missing lateral heat fluxes in the rock, and by errors caused by interpolation of shortwave radiation, wind and air temperature into the rock walls.Mean annual near-surface rock temperature increases were both measured and modelled in the steep rock walls as a consequence of a thick, long-lasting snow cover. Rock temperatures were 1.3–2.5 °C higher in the shaded and sunny rock walls, while comparing snow-covered to snow-free simulations. This helps to assess the potential error made in ground temperature modelling when neglecting snow in steep bedrock.

scholarly journals Simulations of Black Carbon Over Indian Region: Improvements and Implications of Diurnality in Emissions

2019 ◽  
Author(s):  
Gaurav Govardhan ◽  
Sreedharan Krishnakumari Satheesh ◽  
Krishnaswamy Krishna Moorthy ◽  
Ravi Nanjundiah
Keyword(s):  
Boundary Layer ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Regional Scale ◽  
Early Morning ◽  
Temporal Variations ◽  
Indian Region ◽  
Near Surface ◽  
Aerosol Radiative Forcing ◽  
Convective Mixing

Abstract. With a view to improving the performance of WRF-Chem over the Indian region in simulating BC (black Carbon) mass concentrations as well as its short-term variations, especially on diurnal scale, a region-specific diurnal variation scheme has been introduced in the model emissios and the performance of the modified simulations has been evaluated against high-resolution measurements carried out over 8 ARFI (Aerosol Radiative Forcing over India) network observatories spread across India for distinct seasons; pre-monsoon (represented by May), post-monsoon (represented by October) and winter (represented by December). In addition to an overall improvement in the simulated concentrations and their temporal variations, it has also been found that the effects of prescribing diurnally varying emissions on the simulated near-surface concentrations largely depend on the boundary layer turbulence. The effects are perceived fast (within about 2–3 hours) during the evening–early morning hours when the atmospheric boundary layer is shallow and convective mixing is weak, while they are delayed, taking as much as about 5–6 hours, during periods when the boundary layer is deep and convective mixing is strong. This information would also serve as an important input for agencies concerned with urban planning and pollution mitigation. Despite these improvements in the near-surface concentrations, the simulated columnar aerosol optical depth (AOD) still remains largely underestimated vis-a-vis the satellite retrieved products. These modifications will serve as a guideline for further model-improvement initiatives at regional scale.

Examining the Discrepancy between Forecast and Observed Liquefaction from the 2015 Gorkha, Nepal, Earthquakes

2017 ◽  
Vol 33 (1_suppl) ◽  
pp. 73-83 ◽  
Author(s):  
Robb Eric S. Moss ◽  
Laurie G. Baise ◽  
Jing Zhu ◽  
Diwakar Kadkha
Keyword(s):  
Regional Scale ◽  
Groundwater Table ◽  
Earthquake Sequence ◽  
Hazard Mapping ◽  
Kathmandu Valley ◽  
Surface Shear ◽  
Near Surface ◽  
Global Database ◽  
Crust Layer ◽  
Liquefaction Hazard

Many ground failures resulted from the 2015 Nepal earthquake sequence, including landslides, rockfalls, liquefactions, and cyclic failures. And whereas the amount and extent of landsliding were relatively consistent with predictions for a Mw 7.8 main shock, the amount and extent of liquefaction were not. We present a summary of liquefaction field observations that we made as part of the Geotechnical Extreme Events Reconnaissance (GEER) investigations. The liquefaction that did occur in the Kathmandu Valley was limited in its spatial extent, and the postliquefaction deformations were small. Prior earthquakes in this region have been reported to have caused greater liquefaction-related failures, and liquefaction hazard–mapping studies predicted widespread liquefaction hazard from an event of this size. We explore two possible reasons at the regional scale for the limited liquefaction from this earthquake sequence: drawdown of the groundwater table and high near-surface shear wave velocity. Our study finds that pumping has depressed the groundwater table across the Kathmandu Valley by 13–40 m since 1980, thereby decreasing the amount of near-surface liquefiable material and increasing the nonliquefiable “crust” layer. The regional slope-based V S30 for the valley is on average higher than that for liquefaction sites in a global database of observed liquefaction. A global geospatial model for liquefaction occurrence shows low liquefaction potential in the Kathmandu Valley consistent with the observed patterns.

scholarly journals Simulations of black carbon over the Indian region: improvements and implications of diurnality in emissions

2019 ◽  
Vol 19 (12) ◽  
pp. 8229-8241 ◽  
Author(s):  
Gaurav Govardhan ◽  
Sreedharan Krishnakumari Satheesh ◽  
Krishnaswamy Krishna Moorthy ◽  
Ravi Nanjundiah
Keyword(s):  
Boundary Layer ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Regional Scale ◽  
Early Morning ◽  
Temporal Variations ◽  
Indian Region ◽  
Near Surface ◽  
Aerosol Radiative Forcing ◽  
Convective Mixing

Abstract. With a view to improving the performance of WRF-Chem over the Indian region in simulating BC (black carbon) mass concentrations as well as its short-term variations, especially on a diurnal scale, a region-specific diurnal variation scheme has been introduced in the model emissions and the performance of the modified simulations has been evaluated against high-resolution measurements carried out over eight ARFI (Aerosol Radiative Forcing over India) network observatories spread across India for distinct seasons: pre-monsoon (represented by May), post-monsoon (represented by October) and winter (represented by December). In addition to an overall improvement in the simulated concentrations and their temporal variations, we have also found that the effects of prescribing diurnally varying emissions on the simulated near-surface concentrations largely depend on the boundary layer turbulence. The effects are perceived quickly (within about 2–3 h) during the evening–early morning hours when the atmospheric boundary layer is shallow and convective mixing is weak, while they are delayed, taking as much as about 5–6 h, during periods when the boundary layer is deep and convective mixing is strong. This information would also serve as an important input for agencies concerned with urban planning and pollution mitigation. Despite these improvements in the near-surface concentrations, the simulated columnar aerosol optical depth (AOD) still remains largely underestimated vis-à-vis the satellite-retrieved products. These modifications will serve as a guideline for further model-improvement initiatives at a regional scale.

scholarly journals Fifty-Seven-Year California Reanalysis Downscaling at 10 km (CaRD10). Part I: System Detail and Validation with Observations

2007 ◽  
Vol 20 (22) ◽  
pp. 5553-5571 ◽  
Author(s):  
Masao Kanamitsu ◽  
Hideki Kanamaru
Keyword(s):  
Time Scales ◽  
Large Scale ◽  
Global Analysis ◽  
Regional Climate ◽  
Regional Scale ◽  
Surface Wind ◽  
Lateral Boundary ◽  
Climate Change Research ◽  
Near Surface ◽  
Precipitation Analysis

Abstract For the purpose of producing datasets for regional-scale climate change research and application, the NCEP–NCAR reanalysis for the period 1948–2005 was dynamically downscaled to hourly, 10-km resolution over California using the Regional Spectral Model. This is Part I of a two-part paper, describing the details of the downscaling system and comparing the downscaled analysis [California Reanalysis Downscaling at 10 km (CaRD10)] against observation and global analysis. An extensive validation of the downscaled analysis was performed using station observations, Higgins gridded precipitation analysis, and Precipitation-Elevation Regression on Independent Slopes Model (PRISM) precipitation analysis. In general, the CaRD10 near-surface wind and temperature fit better to regional-scale station observations than the NCEP–NCAR reanalysis used to force the regional model, supporting the premise that the regional downscaling is a viable method to attain regional detail from large-scale analysis. This advantage of CaRD10 was found on all time scales, ranging from hourly to decadal scales (i.e., from diurnal variation to multidecadal trend). Dynamically downscaled analysis provides ways to study various regional climate phenomena of different time scales because all produced variables are dynamically, physically, and hydrologically consistent. However, the CaRD10 is not free from problems. It suffers from positive bias in precipitation for heavy precipitation events. The CaRD10 is inaccurate near the lateral boundary where regional detail is damped by the lateral boundary relaxation. It is important to understand these limitations before the downscaled analysis is used for research.

scholarly journals The role of soil in bioclimatology – a review

2008 ◽  
Vol 3 (Special Issue No. 1) ◽  
pp. S30-S41
Author(s):  
K. Rajkai
Keyword(s):  
Plant Cover ◽  
Regional Scale ◽  
Water Storage ◽  
Plant Production ◽  
Co2 Production ◽  
Oak Forest ◽  
Near Surface ◽  
Dew Formation ◽  
Soil Climate ◽  
Local Weather

Soil’s part in bioclimatology is not defined and formulated yet. We interpret soil together with its plant cover as primary climate modifier for organisms living on, and within it. At the same time evaporating soil together with its transpiring vegetation is affecting the climate, and functioning as secondary climate modifier in context of bioclimatology. Selected Hungarian studies are used to highlight four primary and three secondary soil modifier actions connected to bioclimatology. Both primary and secondary soil modifier roles coupled mainly to soil hydro-physical properties. The first primary soil climate modifier action is the dew formation in the surface of sandy soils. As dew 80 mm of water can annually be transported from the subsoil to soil surface. Positive water resource value of dew is still not completely accepted. The second primary soil climate modifier example presents different amounts of usable soil moisture resource in two oak forest habitats with different species composition of herbs. In the third primary soil example the microclimate of the wetter habitat with deeper soil and denser herb vegetation of the oak forest – estimated by inverse modelling – showed higher shading, air moisture content and lower soil coverage than that of dry one. In the fourth primary soil modifier example forest hydrology is quantified for a Scots pine forest. Amount of transpiration, evaporation, interception, and change in the soil water storage were quantified and modelled. As secondary soil climate modifier role CO<sub>2 emitting of different plant production forms and land-uses is shown. Estimated CO2 production burning fuels for soil and plant cultivation is one to threefold of the organic extensive and intensive plant production farm consecutively in 2001. For the estimative calculations cost data of the farms are used. Amount of CO<sub>2</sub> fixed in the crop biomass is also one to threefold as estimated with the regional scale formula of CEEMA (Canadian Economic and Emission Model for Agriculture). Two secondary soil modifier examples of soil texture and land use pattern’s influence on local weather phenomena and near surface atmospheric processes as storm move and development are presented yet. Both studies demonstrate the significance of site-specific soil hydraulic parameters – as field capacity, usable and actual water storage – in formation of the local weather through the soil evaporation and plant transpiration in modelling studies. Of course variety of soil’s role is much wider as the examples show and even it is not known completely at present. Soil’s role in bioclimatology as new discipline will expectably be formulated in the future.

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