scholarly journals Sensitivity of forest–snow interactions to climate forcing: local variability in a Pyrenean valley

2021 ◽  
pp. 127311
Author(s):  
Alba Sanmiguel-Vallelado ◽  
James McPhee ◽  
Paula Esmeralda Ojeda Carreño ◽  
Enrique Morán-Tejeda ◽  
J. Julio Camarero ◽  
...  
Keyword(s):  
Climate Forcing ◽  
Local Variability

Alpine vegetation of the Ivanovskiy, Prokhodnoy and Rossypnoy Ridges (Western Altai)

2015 ◽  
pp. 96-124
Author(s):  
E. G. Zibzeev ◽  
T. A. Nedovesova
Keyword(s):  
Plant Communities ◽  
Wide Spectrum ◽  
Climate Forcing ◽  
High Mountain ◽  
Air Mass ◽  
Rich Diversity ◽  
Mountain Systems ◽  
Mountain Vegetation ◽  
Coenotic Diversity

The mountain systems are characterized by diverse ecological conditions (climate, geomorphological, soil, etc.). The wide spectrum of environmental conditions entails a rich diversity of plant communities growing on the small territory and determines the different flora and vegetation geneses. The uniqueness of floristic and coenotic diversities of the high-mountain vegetation of the south of Western Altai (Ivanovskiy, Prokhodnoi, and Rossypnoi Ranges) are associated with the effect of two climate-forcing factors such as the westerly humid air mass and dry warm airflow from the inner Kazakhstan regions. The paper summarizes the data on coenotic diversity (Zibzeev, 2010, 2012) and gives a syntaxonomic analysis of the high-mountain vege­tation in the Ivanovskii, Prokhodnoi, and Rossypnoi Ranges (Western Altai, Kazakhstan). The classification of plant communities was carried out using the Braun-Blanquet approach (Westhoff, van der Maarel, 1973). The relevés records were stored in the TURBOVEG database and classified by ­TWINSPAN (Hill 1979).

UNCERTAINTY FROM CLIMATE FORCING OF PROJECTIONS IN GLACIER MELT FOR HIGH MOUNTAIN ASIA

2018 ◽  
Vol 74 (4) ◽  
pp. I_211-I_216
Author(s):  
Megumi WATANABE ◽  
Aki YANAGAWA ◽  
Yukiko HIRABAYASHI ◽  
Satoshi WATANABE ◽  
Akiko SAKAI ◽  
...  
Keyword(s):  
Climate Forcing ◽  
High Mountain ◽  
Glacier Melt

scholarly journals Modeling Low Intensity Fires: Lessons Learned from 2012 RxCADRE

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 139
Author(s):  
Rodman R. Linn ◽  
Judith L. Winterkamp ◽  
James H. Furman ◽  
Brett Williams ◽  
J. Kevin Hiers ◽  
...  
Keyword(s):  
Prescribed Fire ◽  
Fire Spread ◽  
Lessons Learned ◽  
Field Sampling ◽  
Wind Fields ◽  
Low Intensity ◽  
Novel Method ◽  
Wind Input ◽  
Variable Wind ◽  
Local Variability

Coupled fire-atmosphere models are increasingly being used to study low-intensity fires, such as those that are used in prescribed fire applications. Thus, the need arises to evaluate these models for their ability to accurately represent fire spread in marginal burning conditions. In this study, wind and fuel data collected during the Prescribed Fire Combustion and Atmospheric Dynamics Research Experiments (RxCADRE) fire campaign were used to generate initial and boundary conditions for coupled fire-atmosphere simulations. We present a novel method to obtain fuels representation at the model grid scale using a combination of imagery, machine learning, and field sampling. Several methods to generate wind input conditions for the model from eight different anemometer measurements are explored. We find a strong sensitivity of fire outcomes to wind inputs. This result highlights the critical need to include variable wind fields as inputs in modeling marginal fire conditions. This work highlights the complexities of comparing physics-based model results against observations, which are more acute in marginal burning conditions, where stronger sensitivities to local variability in wind and fuels drive fire outcomes.

Integrating Regional Frameworks and Local Variability for Riverine Bioassessment

2021 ◽  
Author(s):  
Colby D. Denison ◽  
Mark C. Scott ◽  
Kevin M. Kubach ◽  
Brandon K. Peoples
Keyword(s):  
Local Variability

scholarly journals Modeling of Carbonyl/Ammonium Sulfate Aqueous Brown Carbon Chemistry via UV/Vis Spectral Decomposition

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 358 ◽  
Author(s):  
Mengjie Fan ◽  
Shiqing Ma ◽  
Nahin Ferdousi ◽  
Ziwei Dai ◽  
Joseph L. Woo
Keyword(s):  
Climate Forcing ◽  
Reaction Products ◽  
Brown Carbon ◽  
Reaction Systems ◽  
Reaction Rate Constants ◽  
Kinetic Information ◽  
First Order Kinetics ◽  
Aggregate Effect ◽  
Light Absorbance

The proper characterization of aqueous brown carbon (BrC) species, their formation, and their light absorbance properties is critical to understanding the aggregate effect that they have on overall atmospheric aerosol climate forcing. The contribution of dark chemistry secondary organic aerosol (SOA) products from carbonyl-containing organic compounds (CVOCs) to overall aqueous aerosol optical properties is expected to be significant. However, the multiple, parallel pathways that take place within CVOC reaction systems and the differing chromophoricity of individual products complicates the ability to reliably model the chemical kinetics taking place. Here, we proposed an alternative method of representing UV-visible absorbance spectra as a composite of Gaussian lineshape functions to infer kinetic information. Multiple numbers of curves and different CVOC/ammonium reaction systems were compared. A model using three fitted Gaussian curves with magnitudes following first-order kinetics achieved an accuracy within 65.5% in the 205–300-nm range across multiple organic types and solution aging times. Asymmetrical peaks that occurred in low-200-nm wavelengths were decomposed into two overlapping Gaussian curves, which may have been attributable to different functional groups or families of reaction products. Component curves within overall spectra exhibited different dynamics, implying that the utilization of absorbance at a single reference wavelength to infer reaction rate constants may result in misrepresentative kinetics for these systems.

Summer Differences among Arctic Ecosystems in Regional Climate Forcing

2000 ◽  
Vol 13 (12) ◽  
pp. 2002-2010 ◽  
Author(s):  
F. Stuart Chapin ◽  
Werner Eugster ◽  
Joseph P. McFadden ◽  
Amanda H. Lynch ◽  
Donald A. Walker
Keyword(s):  
Regional Climate ◽  
Climate Forcing ◽  
Arctic Ecosystems

scholarly journals Modeling very large-fire occurrences over the continental United States from weather and climate forcing

2014 ◽  
Vol 9 (12) ◽  
pp. 124009 ◽  
Author(s):  
R Barbero ◽  
J T Abatzoglou ◽  
E A Steel ◽  
Narasimhan K Larkin
Keyword(s):  
United States ◽  
Climate Forcing ◽  
Large Fire ◽  
Weather And Climate

scholarly journals Drivers of changes in stratospheric and tropospheric ozone between year 2000 and 2100

2016 ◽  
Vol 16 (5) ◽  
pp. 2727-2746 ◽  
Author(s):  
Antara Banerjee ◽  
Amanda C. Maycock ◽  
Alexander T. Archibald ◽  
N. Luke Abraham ◽  
Paul Telford ◽  
...  
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Tropospheric Ozone ◽  
Climate Forcing ◽  
Atmospheric Response ◽  
Chemical Production ◽  
The United Kingdom ◽  
Ozone Precursor ◽  
Ozone Depleting Substances ◽  
Year 2000

Abstract. A stratosphere-resolving configuration of the Met Office's Unified Model (UM) with the United Kingdom Chemistry and Aerosols (UKCA) scheme is used to investigate the atmospheric response to changes in (a) greenhouse gases and climate, (b) ozone-depleting substances (ODSs) and (c) non-methane ozone precursor emissions. A suite of time-slice experiments show the separate, as well as pairwise, impacts of these perturbations between the years 2000 and 2100. Sensitivity to uncertainties in future greenhouse gases and aerosols is explored through the use of the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. The results highlight an important role for the stratosphere in determining the annual mean tropospheric ozone response, primarily through stratosphere–troposphere exchange (STE) of ozone. Under both climate change and reductions in ODSs, increases in STE offset decreases in net chemical production and act to increase the tropospheric ozone burden. This opposes the effects of projected decreases in ozone precursors through measures to improve air quality, which act to reduce the ozone burden. The global tropospheric lifetime of ozone (τO3) does not change significantly under climate change at RCP4.5, but it decreases at RCP8.5. This opposes the increases in τO3 simulated under reductions in ODSs and ozone precursor emissions. The additivity of the changes in ozone is examined by comparing the sum of the responses in the single-forcing experiments to those from equivalent combined-forcing experiments. Whilst the ozone responses to most forcing combinations are found to be approximately additive, non-additive changes are found in both the stratosphere and troposphere when a large climate forcing (RCP8.5) is combined with the effects of ODSs.

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