A5071838683- Atmospheric and Environmental Gas Dynamics
- Spectroscopy and Laser Applications
- Plant Water Relations and Carbon Dynamics
- Atmospheric Ozone and Climate
- Plant responses to elevated CO2
- Climate variability and models
- Atmospheric chemistry and aerosols
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Soil Carbon and Nitrogen Dynamics
- Peatlands and Wetlands Ecology
- Remote Sensing in Agriculture
- Soil and Unsaturated Flow
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Physics Studies
- Laser-induced spectroscopy and plasma
- Hydrocarbon exploration and reservoir analysis
- Isotope Analysis in Ecology
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- Astro and Planetary Science
- Air Quality and Health Impacts
- Tree-ring climate responses
- Spacecraft and Cryogenic Technologies
- Spectroscopy and Chemometric Analyses
Aerodyne Research
2021-2025
University of Arizona
2013-2023
Planetary Science Institute
2013
Harvard University
2013
National Interuniversity Consortium for the Physical Sciences of Matter
2007-2009
Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
2008
University of Toronto
2001-2007
Abstract. For the past decade, observations of carbonyl sulfide (OCS or COS) have been investigated as a proxy for carbon uptake by plants. OCS is destroyed enzymes that interact with CO2 during photosynthesis, namely carbonic anhydrase (CA) and RuBisCO, where CA more important one. The majority sources to atmosphere are geographically separated from this large plant sink, whereas sinks co-located in ecosystems. drawdown can therefore be related without added complication emissions...
We review our recent results in development of high-precision laser spectroscopic instrumentation using midinfrared quantum cascade lasers (QCLs). Some these instruments have been directed at measurements atmospheric trace gases where a fractional precision 10−3 or better ambient concentration may be required. Such high is needed fluxes stable and isotopic ratios. Instruments that are based on thermoelectrically cooled QCLs detectors demonstrated meet the requirements measurements, without...
Abstract. Stomatal conductance influences both photosynthesis and transpiration, thereby coupling the carbon water cycles affecting surface–atmosphere energy exchange. The environmental response of stomatal has been measured mainly on leaf scale, theoretical canopy models are relied to upscale for application in terrestrial ecosystem climate prediction. Here we estimate associated transpiration a temperate deciduous forest directly scale via two independent approaches: (i) from heat vapor...
Gross ecosystem productivity (GEP) in tropical forests varies both with the environment and biotic changes photosynthetic infrastructure, but our understanding of relative effects these factors across timescales is limited. Here, we used a statistical model to partition variability seven years eddy covariance-derived GEP central Amazon evergreen forest into two main causes: variation environmental drivers (solar radiation, diffuse light fraction, vapor pressure deficit) that interact...
Abstract. The uptake of carbonyl sulfide (COS) by terrestrial plants is linked to photosynthetic CO2 as these gases partly share the same pathway. Applying COS a photosynthesis tracer in models requires an accurate representation biosphere fluxes, but have not been extensively evaluated against field observations fluxes. In this paper, flux simulated Simple Biosphere Model, version 4 (SiB4), updated with latest mechanistic insights and site from different biomes: one evergreen needleleaf...
Abstract. Land surface modellers need measurable proxies to constrain the quantity of carbon dioxide (CO2) assimilated by continental plants through photosynthesis, known as gross primary production (GPP). Carbonyl sulfide (COS), which is taken up leaves their stomates and then hydrolysed photosynthetic enzymes, a candidate GPP proxy. A former study with ORCHIDEE land model used fixed ratio COS uptake CO2 normalised respective ambient concentrations for each vegetation type (leaf relative...
We report on a new optical implementation of primary gas thermometry based laser-absorption spectrometry in the near infrared. The method consists retrieving Doppler broadening from highly accurate observations line shape $R(12)$ ${\ensuremath{\nu}}_{1}+2{\ensuremath{\nu}}_{2}^{0}+{\ensuremath{\nu}}_{3}$ transition ${\mathrm{CO}}_{2}$ at thermodynamic equilibrium. width measurements as function temperature, ranging between triple point water and gallium melting point, allowed for...
Abstract. For the past decade, observations of carbonyl sulfide (OCS or COS) have been investigated as a proxy for carbon uptake by plants. OCS is destroyed enzymes that interact with CO2 during photosynthesis, namely carbonic anhydrase (CA) and RuBisCO, where CA more important. The majority sources to atmosphere are geographically separated from this large plant sink, whereas sinks co-located in ecosystems. drawdown can therefore be related without added complication emissions comparable...
Abstract. Carbonyl sulfide (COS) is an atmospheric trace gas of interest for C cycle research because COS uptake by continental vegetation strongly related to terrestrial gross primary productivity (GPP), the largest and most uncertain flux in CO2 budgets. However, use as additional tracer GPP, accurate quantification exchange soils also needed. At present, budget unbalanced globally, with total estimates from oxic anoxic that vary between −409 −89 GgS yr−1. This uncertainty hampers...
Abstract. Canopy stomatal conductance is commonly estimated from eddy covariance measurements of the latent heat flux (LE) by inverting Penman–Monteith equation. That method ignores sensible (H) and instead calculates H implicitly as residual all other terms in site energy budget. Here we show that canopy more accurately calculated (EC) both LE using flux–gradient equations define underlie equation, especially when budget fails to close due pervasive biases fluxes and/or available energy....
While wetlands are major sources of biogenic methane (CH
An intensity-stabilized diode laser absorption spectrometer was developed and used to perform a highly accurate study of the line shape CO(2) lines, in spectral region around 5000 cm(-1), belonging nu(1) + 2nu(2)(0) nu(3) combination band, at temperature 296.00 K. Standard complex semiclassical models, including Dicke narrowing speed-dependent broadening effects, were applied, tested, compared pressure range between 0.7 4 kPa, order single out model best reproducing profile and, hence,...
Abstract. It has been almost 50 years since York published an exact and general solution for the best-fit straight line to independent points with normally distributed errors in both x y. York's is highly cited geophysical literature but unknown outside of it, so that there no ebb tide books papers wrestling problem. Much post-1969 on straight-line fitting sown confusion not merely by its content very existence. The optimal least-squares fit already known; problem solved. Here we introduce...
Abstract Spatiotemporal variability in ozone dry deposition is often overlooked despite its implications for interpreting and modeling tropospheric concentrations accurately. Understanding the influences of stomatal versus nonstomatal processes on velocity important attributing observed changes depositional sink associated damage to ecosystems. Here, we aim identify driving over northeastern United States during June–September. We use eddy covariance measurements from Harvard Forest...
Fugitive and operational hydrogen (H2) emissions have been shown to offset the intended climate benefits of H2 as a decarbonization tool because indirectly causes warming through atmospheric chemistry. However, little is known about magnitude value-chain due lack empirical measurements, unavailability precise, fast sensor technology, established methods for emission quantification. In this study, novel prototype was deployed in state-of-the-art mobile laboratory demonstrate that can be...
We present measurements of the shifts and widths rovibrational lines fundamental band CO highly diluted in He Ar at 296 K. The are decomposed into parts odd even line number, m. These then compared with close coupled calculations carried out best known interaction potentials. There is general agreement between calculated measured values broadening shifting. Furthermore, results illustrate that decomposition parts, m, a powerful tool for separating relative contributions isotropic anisotropic...
An intensity-stabilized laser absorption spectrometer, which incorporates a mirror-extended cavity diode laser, temperature-stabilized gas cell, and Michelson interferometer, was developed applied to highly accurate investigation of line intensity factors within the nu(1)+2nu(2) (0)+nu(3) combination band carbon dioxide, around 2 microm wavelength, at temperature 296.0 K. This relatively complex apparatus enables one observe shape with high precision accuracy in such way that it is possible...
Abstract. Carbonyl sulfide (COS) is a useful tracer to estimate gross primary production (GPP) because it shares part of the uptake pathway with CO2. COS taken up in plants through hydrolysis, catalyzed by enzyme carbonic anhydrase (CA), but not released. The Simple Biosphere model version 4 (SiB4) simulates leaf using conductance approach. SiB4 applies temperature response RuBisCo (used for photosynthesis) simulate uptake, CA might respond differently temperature. We introduce new function...