scholarly journals Integrating Remote and In-Situ Data to Assess the Hydrological Response of a Post-Fire Watershed

Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 169
Author(s):  
Luca Folador ◽  
Alessio Cislaghi ◽  
Giorgio Vacchiano ◽  
Daniele Masseroni
Keyword(s):  
Forest Fires ◽  
Hydrological Response ◽  
Soil Infiltration ◽  
Infiltration Capacity ◽  
Flood Peak ◽  
Burned Areas ◽  
In Situ Data ◽  
The Impact ◽  
Fire Conditions

Forest fire is a common concern in Mediterranean watersheds. Fire-induced canopy mortality may cause the degradation of chemical–physical properties in the soil and influence hydrological processes within and across watersheds. However, the prediction of the pedological and hydrological effect of forest fires with heterogenous severities across entire watersheds remains a difficult task. A large forest fire occurred in 2017 in northern Italy providing the opportunity to test an integrated approach that exploits remote and in-situ data for assessing the impact of forest fires on the hydrological response of semi-natural watersheds. The approach is based on a combination of remotely-sensed information on burned areas and in-situ measurements of soil infiltration in burned areas. Such collected data were used to adapt a rainfall–runoff model over an experimental watershed to produce a comparative evaluation of flood peak and volume of runoff in pre- and post-fire conditions. The model is based on a semi-distributed approach that exploits the Soil Conservation Service Curve Number (SCS-CN) and lag-time methods for the estimation of hydrological losses and runoff propagation, respectively, across the watershed. The effects of fire on hydrological losses were modeled by adjusting the CN values for different fire severities. Direct infiltration measurements were carried out to better understand the effect of fire on soil infiltration capacity. We simulated the hydrological response of the burned watershed following one of the most severe storm events that had hit the area in the last few years. Fire had serious repercussions in regard to the hydrological response, increasing the flood peak and the runoff volume up to 125% and 75%, respectively. Soil infiltration capacity was seriously compromised by fire as well, reducing unsaturated hydraulic conductivity up to 75% compared with pre-fire conditions. These findings can provide insights into the impact of forest fires on the hydrological response of a whole watershed and improve the assessment of surface runoff alterations suffered by a watershed in post-fire conditions.

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

2016 ◽  
Vol 16 (14) ◽  
pp. 9435-9455 ◽  
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.

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

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.

scholarly journals INTERCEPTION AND INFILTRATION OF RAINWATER ON THE LAND OF EX FOREST FIRE ON TAHURA R. SOERJO LEDUG BLOCK

2019 ◽  
Vol 2 (1) ◽  
pp. 29
Author(s):  
Oktavian Dwi Suhermanto ◽  
Tatag Muttaqin ◽  
Nugroho Tri Waskitho
Keyword(s):  
Forest Fire ◽  
Forest Fires ◽  
Soil Infiltration ◽  
Infiltration Capacity ◽  
Hydrological System ◽  
Fire Area

Forest fires often occur in many islands of indonesia including in Kalimantan, Sumatra, Java, Sulawesi and other regions. These fires can lead to damage for ecosystems, flora and fauna, even ecosystem hydrology. One of the hydrological system that was disturbed is the interception and infiltration. Interception is the ability of trees to retain water rain then rereleased in steam. Infiltration is the process of water absorbing into the soil, infiltration capacity is the soil’s ability of absorbing water per unit of time. This research is to know the rest of the tree's ability to retain water, and knowing the infiltration of ex forest fire area on TAHURA R. Soerjo, Ledug blocks. This research was carried out on 17-23 January 2019 in ex forest fire area on TAHURA R. Soerjo, with an elevation of 1100-1200 masl. In the ex forest fire area there are 2 dominant trees species to do measurements of interception, there are Tutup (Mallotus paniculatus) and Klerek (Sapindus rarak DC). The results of the interception on Klerek tree is 10% and Tutup is 60%.  For the capacity of the infiltration is 27, 6 mm/hour. 

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

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

<p>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.</p><p>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.</p><p>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.</p>

scholarly journals Fire takes no vacation: impact of fires on tourism

2021 ◽  
pp. 1-16
Author(s):  
Vladimir Otrachshenko ◽  
Luis C. Nunes
Keyword(s):  
Forest Fires ◽  
Impact Analysis ◽  
Negative Impact ◽  
Burned Areas ◽  
The World ◽  
Portuguese Economy ◽  
Increasing Risk ◽  
The Portuguese Economy ◽  
Using Data ◽  
The Impact

Abstract Many Mediterranean-type climates around the world will face increased risks of wildfires as a consequence of climate change. In this study we consider the case of Portugal and estimate the impact of the increasing risk of forest fires on tourism. Using data for 278 municipalities for the 2000–2016 period, we find a considerable negative impact of burned areas on the number of tourist arrivals, both domestic and inbound. We go beyond the traditional impact analysis and provide predictions for 2030 and 2050. The estimated annual costs to the Portuguese economy due to the impact of burned areas in 2030 range between €17.03 and 24.18 million for domestic tourist arrivals and between €18.26 and 38.08 million for inbound ones. In 2050, those costs will increase at least fourfold. These findings underscore the importance of taking the forest fire risks into account when planning local investments.

The impact of wildfires in Ukraine on carbon flux and air quality changes by carbon-containing compounds

2021 ◽  
Author(s):  
Mykhailo Savenets ◽  
Larysa Pysarenko
Keyword(s):  
Air Quality ◽  
Carbon Emissions ◽  
Forest Fires ◽  
Content Increase ◽  
Total Contribution ◽  
Open Burning ◽  
Fire Emissions ◽  
Burned Areas ◽  
Summer Maximum ◽  
The Impact

<p>Wildfires remain among the most challenging problems in Ukraine. Each year numerous cases of open burning contribute to huge carbon emissions and turn into forest fires. Using the Global Fire Emissions Database (GFED4), there were studied an average burned fraction in Ukraine, which equals of about 0.2-0.3. 90% of wildfires appeared on agricultural lands. The total contribution to carbon emissions is 0.2-1.0 g·m<sup>2</sup>·month<sup>-1</sup> with the increasing trend of about 1-2 g·m<sup>2</sup>·month<sup>-1</sup> per decade. There are three periods with the highest carbon emissions: April, July-August and September-October. While a summer maximum is corresponding to unfavorable temperature and moisture regimes, the main reason of wildfires in spring and autumn is the agricultural open burning. Based on the Sentinel-5P data, it was found that wildfires significantly change the seasonality of carbon monoxide (CO) variations. If maximal CO content is mainly observed in winter at the end of the heating season, in Ukraine the highest CO values continue to exist in April until the open burning stops and the resulting forest fires are extinguished. Wildfires caused the CO content increase to 4.0–5.0 mol·m<sup>-2</sup> which is comparable to the most polluted Ukrainian industrial cities. As a result, air quality deterioration observed at the distances more than 200 km from the burned areas. Using the Enviro-HIRLAM simulations, there were estimated black carbon (BC) distribution, which showed elevated content within the lowest 3-km layer. BC content reaches 600 ppbm near the active fires, 150 ppbm at the distance up to 100 km and 30 ppbm at the distance of about 200-500 km.</p>

What does really happen in a dust impact?

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

<p>Our current understanding of the solar system’s micrometeoroid environment relies to a substantial extent on in-situ data acquired by impact ionization dust detectors such as Ulysses’ and Galileo’s DDS or Cassini’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.<span> </span></p><p>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.<span> </span></p><p>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.</p>

scholarly journals 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

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.

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

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.

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

Ocean Science ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1707-1728 ◽  
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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