Evaluation of Gridded and In Situ Precipitation Datasets on Modeled Glacio-Hydrologic Response of a Small Glacierized Himalayan Catchment

Abstract Reliable precipitation data in the Himalayas are essential for the study of the water resources, the evolution of glaciers, and the present and future climate. Although several types of precipitation datasets are available for the Himalayan region, all of them have limitations, which hamper the quantification of the precipitation fluxes at high elevations. This study compares different types of precipitation datasets issued from (i) in situ data, (ii) satellite-based data [TRMM, Climate Hazards Group Infrared Precipitation with Station Data (CHIRPS)], and (iii) a reanalysis product [High Asia Refined analysis (HAR)] for a small headwater catchment at high elevations (Upper Dudh Koshi, Nepal) and assesses the impact of the precipitation uncertainty on the result of the modeling of the glacio-hydrological system. During the analyzed period from 2010 to 2015, large differences between the precipitation datasets occur regarding annual amounts (ranging from 410 to 1190 mm yr−1) as well as in seasonal and diurnal cycles. The simulations with the glacio-hydrological model Distributed Hydrological Soil Vegetation Model–Glaciers Dynamics Model (DHSVM-GDM) show that the choice of a given precipitation dataset greatly impacts the simulated snow cover dynamics and glacier mass balances as well as the annual, seasonal, and diurnal streamflows. Due to the uncertainty in the precipitation, the simulated contribution of the ice melt to the annual outflow also remains uncertain and simulated fractions range from 29% to 76% for the 2012–13 glaciological year.

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Evaluating model parameterizations of submicron aerosol scattering and absorption with in situ data from ARCTAS 2008

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-9435-2016 ◽

2016 ◽

Vol 16 (14) ◽

pp. 9435-9455 ◽

Cited By ~ 8

Author(s):

Matthew J. Alvarado ◽

Chantelle R. Lonsdale ◽

Helen L. Macintyre ◽

Huisheng Bian ◽

Mian Chin ◽

...

Keyword(s):

Optical Properties ◽

Size Distribution ◽

Aerosol Size Distribution ◽

Visible Radiation ◽

Submicron Aerosol ◽

In Situ Data ◽

Aerosol Absorption ◽

Aerosol Scattering ◽

The Impact

Abstract. Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10–23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction throughout the aerosol size distribution. Using a core-shell mixing rule in ASP overestimates aerosol absorption, especially for the fresh biomass burning aerosol measured in ARCTAS-B, suggesting the need for modeling the time-varying mixing states of aerosols in future versions of ASP.

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Experimental tests of the impact of selected parameters on the indentation rolling resistances

E3S Web of Conferences ◽

10.1051/e3sconf/20182900002 ◽

2018 ◽

Vol 29 ◽

pp. 00002 ◽

Cited By ~ 1

Author(s):

Dariusz Woźniak ◽

Lech Gładysiewicz ◽

Martyna Konieczna

Keyword(s):

Main Part ◽

Rolling Resistance ◽

Experimental Tests ◽

Conveyor Belt ◽

Significant Component ◽

Different Types ◽

Indentation Rolling Resistance ◽

Belt Conveyors ◽

The Impact

Belt conveyors are main part of transporting systems in mines and in many other branches of industry. During conveyor belt works different types of resistances are generated. Indentation rolling resistance is the most significant component of the resistances from the perspective of energy losses and it cause the biggest costs as well. According to latest state of analyses and measurements it is well known that theoretical rolling resistance were underestimated in comparison with the measured in-situ one. In this paper new method for determination indentation rolling resistance is presented. The authors compared theoretically and experimentally established damping factors. The relation between these two values enabled to obtain more precise equation for damping function. This function is one of the most important component in calculation of the rolling resistance. In new theoretical model value of rolling resistance is nearly twice higher than this used so far.

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Evaluating Model Parameterizations of Submicron Aerosol Scattering and Absorption with In Situ Data from ARCTAS 2008

10.5194/acp-2015-935 ◽

2016 ◽

Author(s):

M. J. Alvarado ◽

C. R. Lonsdale ◽

H. L. Macintyre ◽

H. Bian ◽

M. Chin ◽

...

Keyword(s):

Optical Properties ◽

Size Distribution ◽

Aerosol Size Distribution ◽

Visible Radiation ◽

Submicron Aerosol ◽

In Situ Data ◽

Aerosol Absorption ◽

Aerosol Scattering ◽

The Impact

Abstract. Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution is used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10–23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding in situ size distribution information, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction through out the aerosol size distribution. Using a core-shell mixing state in ASP overestimates aerosol absorption, especially for the fresh biomass burning aerosol measured in ARCTAS-B, suggesting the need for time-varying mixing states in future versions of ASP.

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An inventory and assessment of glaciers, rock glaciers, perennial snowfields, and permafrost landforms in the Teton Range, WY, USA

The UW National Parks Service Research Station Annual Reports ◽

10.13001/uwnpsrc.2018.5639 ◽

2018 ◽

Vol 41 ◽

pp. 1-4

Author(s):

Paepin D. Goff ◽

David R. Butler

Keyword(s):

Aerial Photography ◽

Ecological Systems ◽

Ecological Impacts ◽

Mountain Watersheds ◽

Hydrological System ◽

Rock Glaciers ◽

Greater Yellowstone ◽

Teton Range ◽

The Impact

Glaciers, rock glaciers, and permafrost landforms store water within ice reserves in alpine and periglacial zones. In the Greater Yellowstone Ecosystem of northwestern Wyoming, U.S.A., these landforms charge the hydrological system through meltwater, which raises questions about the ecological impacts of these limited water reserves in a regime trending toward warmer and drier conditions. Here, I investigate the impact of glacier and rock glacier meltwater on the ecological systems within the Grand Teton, Wind River, and Gros Ventre mountain watersheds. This investigation relies on remotely sensed satellite imagery, aerial photography, and Lidar, as well as in situ field data. With these data, I provide a high-resolution inventory of glacial, rock glacial, and permafrost landforms in the GYE. Featured photo by Grand Teton on Flickr. https://flic.kr/p/2hwtrRb

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Performance gains in an ESM using parallel ad-hoc file systems

10.5194/egusphere-egu2020-18121 ◽

2020 ◽

Author(s):

Stefan Versick ◽

Ole Kirner ◽

Jörg Meyer ◽

Holger Obermaier ◽

Mehmet Soysal

Keyword(s):

High Performance ◽

Ad Hoc ◽

File System ◽

File Systems ◽

System Modelling ◽

Earth System ◽

Post Processing ◽

In Situ Data ◽

The Impact

Earth System Models (ESM) got much more demanding over the last years. Modelled processes got more complex and more and more processes are considered in models. In addition resolutions of the models got higher to improve weather and climate forecasts. This requires faster high performance computers (HPC) and better I/O performance.Within our Pilot Lab Exascale Earth System Modelling (PL-EESM) we do performance analysis of the ESM EMAC using a standard Lustre file system for output and compare it to the performance using a parallel ad-hoc overlay file system. We will show the impact for two scenarios: one for todays standard amount of output and one with artificial heavy output simulating future ESMs.An ad-hoc file system is a private parallel file system which is created on-demand for an HPC job using the node-local storage devices, in our case solid-state-disks (SSD). It only exists during the runtime of the job. Therefore output data have to be moved to a permanent file system before the job has finished. Quasi in-situ data analysis and post-processing allows to gain performance as it might result in a decreased amount of data which you have to store - saving disk space and time during the transfer of data to permanent storage. We will show first tests for quasi in-situ post-processing.

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What does really happen in a dust impact?

10.5194/egusphere-egu2020-20089 ◽

2020 ◽

Author(s):

Sascha Kempf ◽

William Goode ◽

Ralf Srama ◽

Frank Postberg

Keyword(s):

Rise Time ◽

Impact Ionization ◽

Dust Particles ◽

Ionization Mass ◽

Mass Spectrometers ◽

Ample Evidence ◽

In Situ Data ◽

The Impact ◽

Ionization Detectors

Our current understanding of the solar system&#8217;s micrometeoroid environment relies to a substantial extent on in-situ data acquired by impact ionization dust detectors such as Ulysses&#8217; and Galileo&#8217;s DDS or Cassini&#8217;s CDA. Such detectors derive the mass and speed of striking dust particles from the properties and evolution of the plasma created upon impact. In particular, empirical evidence suggests that the impact speed is a function of the duration of impact charge delivery onto the target - the so-called plasma rise time. Often, this dependence has been attributed to secondary impacts of target and projectile ejecta.&#160;During recent years the capabilities of laboratory impact detectors have been significantly improved. In particular we now have ample evidence that secondary ejecta impacts are not responsible for the rise-time dependence. In fact the plasma rise-time is rather related to the ionization of target contaminants in the vicinity of the impact site.&#160;In this talk we present new experimental data obtained with state-of-the-art impact ionization mass spectrometers, which shed new light on what is really going on during a hypervelocity dust impact. We further discuss the implications for the interpretation of dust data obtained with previous generations of impact ionization detectors.

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Steffen K, Abdalati W and Stroeve J (1993) Climate sensitivity studies of the Greenland ice sheet using satellite AVHRR, SMMR SSM/I and in situ data. Meteorology and Atmospheric Physics 51(3–4): 239–258. DOI:10.1007/bf01030497

Progress in Physical Geography Earth and Environment ◽

10.1177/03091333211011368 ◽

2021 ◽

pp. 030913332110113

Author(s):

Jason E. Box ◽

Julienne C. Stroeve ◽

Waleed Abdalati

Keyword(s):

Climate Change ◽

Satellite Remote Sensing ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Field Observations ◽

Atmospheric Physics ◽

In Situ Data ◽

Sensitivity Studies ◽

The Impact

Physical geographer Konrad “Koni” Steffen, lost 8 August 2020 in a crevasse on the Greenland ice sheet, was a pioneer in satellite remote sensing and field observations of the Greenland ice sheet. This Classics Revisited piece honors the memory of Koni Steffen and examines the impact of a work which laid the foundation for numerous studies that made the Greenland ice sheet and the man global icons of climate change.

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Four years of global carbon cycle observed from OCO-2 version 9 and in situ data, and comparison to OCO-2 v7

10.5194/acp-2021-373 ◽

2021 ◽

Author(s):

Hélène Peiro ◽

Sean Crowell ◽

Andrew Schuh ◽

David F. Baker ◽

Chris O'Dell ◽

...

Keyword(s):

Carbon Emissions ◽

Total Carbon ◽

Tropical Africa ◽

Times Series ◽

In Situ Data ◽

The Times ◽

Carbon Dioxide Co2 ◽

The Tropics ◽

The Impact

Abstract. The Orbiting Carbon Observatory 2 (OCO-2) satellite has been provided information to estimate carbon dioxide (CO2) fluxes at global and regional scales since 2014 through the combination of CO2 retrievals with top-down atmospheric inversion methods. Column average CO2 dry air mole fraction retrievals has been constantly improved. A bias correction has been applied in the OCO-2 version 9 retrievals compared to the previous OCO-2 version 7r improving data accuracy and coverage. We study an ensemble of ten atmospheric inversions all characterized by different transport models, data assimilation algorithm and prior fluxes using first OCO-2 v7 in 2015-2016 and then OCO-2 version 9 land observations for the longer period 2015- 2018. Inversions assimilating in situ (IS) measurements have been also used to provide a baseline against which to compare the satellite-driven results. The times series at different scales (going from global to regional scales) of the models emissions are analyzed and compared to each experiments using either OCO-2 or IS data. We then evaluate the inversion ensemble based on dataset from TCCON, aircraft, and in-situ observations, all independent from assimilated data. While we find a similar constraint of global total carbon emissions between the ensemble spread using IS and both OCO-2 retrievals, differences between the two retrieval versions appear over regional scales and particularly in tropical Africa. A difference in the carbon budget between v7 and v9 is found over this region which seems to show the impact of corrections applied in retrievals. However, the lack of data in the tropics limits our conclusions and the estimation of carbon emissions over tropical Africa require further analysis.

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The FluxEngine air–sea gas flux toolbox: simplified interface and extensions for in situ analyses and multiple sparingly soluble gases

Ocean Science ◽

10.5194/os-15-1707-2019 ◽

2019 ◽

Vol 15 (6) ◽

pp. 1707-1728 ◽

Cited By ~ 3

Author(s):

Thomas Holding ◽

Ian G. Ashton ◽

Jamie D. Shutler ◽

Peter E. Land ◽

Philip D. Nightingale ◽

...

Keyword(s):

Gas Transfer ◽

Illustrative Case ◽

Observation Data ◽

Co2 Fluxes ◽

In Situ Data ◽

First Case ◽

Gas Fluxes ◽

The Impact

Abstract. The flow (flux) of climate-critical gases, such as carbon dioxide (CO2), between the ocean and the atmosphere is a fundamental component of our climate and an important driver of the biogeochemical systems within the oceans. Therefore, the accurate calculation of these air–sea gas fluxes is critical if we are to monitor the oceans and assess the impact that these gases are having on Earth's climate and ecosystems. FluxEngine is an open-source software toolbox that allows users to easily perform calculations of air–sea gas fluxes from model, in situ, and Earth observation data. The original development and verification of the toolbox was described in a previous publication. The toolbox has now been considerably updated to allow for its use as a Python library, to enable simplified installation, to ensure verification of its installation, to enable the handling of multiple sparingly soluble gases, and to enable the greatly expanded functionality for supporting in situ dataset analyses. This new functionality for supporting in situ analyses includes user-defined grids, time periods and projections, the ability to reanalyse in situ CO2 data to a common temperature dataset, and the ability to easily calculate gas fluxes using in situ data from drifting buoys, fixed moorings, and research cruises. Here we describe these new capabilities and demonstrate their application through illustrative case studies. The first case study demonstrates the workflow for accurately calculating CO2 fluxes using in situ data from four research cruises from the Surface Ocean CO2 ATlas (SOCAT) database. The second case study calculates air–sea CO2 fluxes using in situ data from a fixed monitoring station in the Baltic Sea. The third case study focuses on nitrous oxide (N2O) and, through a user-defined gas transfer parameterisation, identifies that biological surfactants in the North Atlantic could suppress individual N2O sea–air gas fluxes by up to 13 %. The fourth and final case study illustrates how a dissipation-based gas transfer parameterisation can be implemented and used. The updated version of the toolbox (version 3) and all documentation is now freely available.

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Uncertainties in modeling heterogeneous chemistry and Arctic ozone depletion in the winter 2009/2010

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-26245-2012 ◽

2012 ◽

Vol 12 (10) ◽

pp. 26245-26295 ◽

Cited By ~ 3

Author(s):

I. Wohltmann ◽

T. Wegner ◽

R. Müller ◽

R. Lehmann ◽

M. Rex ◽

...

Keyword(s):

Transport Model ◽

Particle Number Density ◽

Rate Coefficients ◽

The Arctic ◽

Satellite Measurements ◽

Mixing Ratios ◽

Different Types ◽

Stratospheric Clouds ◽

The Impact

Abstract. Stratospheric chemistry and denitrification are simulated for the Arctic winter 2009/2010 with the Lagrangian Chemistry and Transport Model ATLAS. A number of sensitivity runs is used to explore the impact of uncertainties in chlorine activation and denitrification on the model results. In particular, the efficiency of chlorine activation on different types of liquid aerosol versus activation on nitric acid trihydrate clouds is examined. Additionally, the impact of changes in reaction rate coefficients, in the particle number density of polar stratospheric clouds, in supersaturation, temperature or the extent of denitrification is investigated. Results are compared to satellite measurements of MLS and ACE-FTS and to in-situ measurements onboard the Geophysica aircraft during the RECONCILE measurement campaign. It is shown that even large changes in the underlying assumptions have only a small impact on the modeled ozone loss, even though they can cause considerable differences in chemical evolution and denitrification. In addition, it is shown that chlorine activation on liquid aerosols alone is able to explain the observed magnitude and morphology of the mixing ratios of active chlorine, reservoir gases and ozone.

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