A5040011766- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Marine and coastal ecosystems
- Ocean Acidification Effects and Responses
- Ionosphere and magnetosphere dynamics
- Methane Hydrates and Related Phenomena
- Spectroscopy and Laser Applications
- Oceanographic and Atmospheric Processes
- Climate variability and models
- Advanced Chemical Sensor Technologies
- Isotope Analysis in Ecology
- Polar Research and Ecology
- Sulfur Compounds in Biology
- Speech and dialogue systems
- Climate change and permafrost
- Geological Studies and Exploration
- Geophysics and Gravity Measurements
- Air Quality Monitoring and Forecasting
- Hydrocarbon exploration and reservoir analysis
- Solar and Space Plasma Dynamics
- Geology and Paleoclimatology Research
- Astro and Planetary Science
- Marine and environmental studies
NSF National Center for Atmospheric Research
2016-2021
Scripps Institution of Oceanography
2013-2021
University of California, San Diego
2013-2021
Picarro (United States)
2020-2021
National Oceanic and Atmospheric Administration
2017
University of Colorado Boulder
2017
Institute of Oceanography
2014
Downs and Ups Every spring, the concentration of CO 2 in atmosphere Northern Hemisphere decreases as terrestrial vegetation grows, every fall, rises dies rots. Climate change has destabilized seasonal cycle atmospheric such that Graven et al. (p. 1085 , published online 8 August; see Perspective by Fung ) have found amplitude exceeded 50% at some latitudes. The only way to explain this increase is if extratropical land ecosystems are growing shrinking more than they did half a century ago,...
Abstract. We present an evaluation of aircraft observations the carbon and greenhouse gases CO2, CH4, N2O, CO using a direct-absorption pulsed quantum cascade laser spectrometer (QCLS) operated during HIPPO CalNex airborne experiments. The QCLS made continuous 1 Hz measurements with 1σ Allan precisions 20, 0.5, 0.09, 0.15 ppb for CO, respectively, over > 500 flight hours on 79 research flights. are compared to two vacuum ultraviolet (VUV) instruments (CalNex HIPPO), cavity ring-down...
Abstract The Southern Ocean plays a critical role in the global climate system by mediating atmosphere–ocean partitioning of heat and carbon dioxide. However, Earth models are demonstrably deficient Ocean, leading to large uncertainties future air–sea CO2 flux projections under warming incomplete interpretations natural variability on interannual geologic time scales. Here, we describe recent aircraft observational campaign, O2/N2 Ratio Airborne (ORCAS) study, which collected measurements...
Abstract. We have developed in situ and flask sampling systems for airborne measurements of variations the O2/N2 ratio at part per million level. deployed these instruments on a series aircraft campaigns to measure distribution atmospheric O2 from 0–14 km 87∘ N 86∘ S throughout seasonal cycle. The National Center Atmospheric Research (NCAR) oxygen instrument (AO2) uses vacuum ultraviolet (VUV) absorption detector also includes an infrared CO2 sensor. VUV has precision 5 s ±1.25 meg (1σ)...
Abstract Observed seasonal cycles in atmospheric potential oxygen (APO ~ O 2 + 1.1 CO ) were used to evaluate eight ocean biogeochemistry models from the Coupled Model Intercomparison Project (CMIP5). APO computed CMIP5 air‐sea and fluxes compared observations at three Southern Hemisphere monitoring sites. Four of captured either observed amplitude or phasing relatively well, while other four did not. Many had an unrealistic flux, which turn influenced APO. By 2100 under RCP8.5, projected...
Abstract. Accurate simulation of atmospheric circulation, particularly in the lower stratosphere, is challenging due to unresolved wave–mean flow interactions and limited high-resolution observations for validation. Gravity-induced pressure gradients lead a small but measurable separation heavy light gases by molecular diffusion stratosphere. Because relative abundance Ar N2 exclusively controlled physical transport, argon-to-nitrogen ratio (Ar∕N2) provides an additional constraint on...
Abstract We present airborne observations of the vertical gradient atmospheric oxygen ( δ (O 2 /N )) and carbon dioxide (CO ) through boundary layer (BL) over Drake Passage region Southern Ocean, during O Ratio CO Airborne Ocean Study, from 15 January to 29 February 2016. Gradients were predominately anticorrelated, with excesses depletions found within layer, relative a mean reference height 1.7 km. Through analysis molar ratio gradients (GR), behavior other trace gases measured in situ,...
Abstract. We have developed in situ and flask sampling systems for airborne measurements of variations the O2/N2 ratio at part per million level. deployed these instruments on a series aircraft campaigns to measure distribution atmospheric O2 from 0–14 km 87° N 85° S throughout seasonal cycle. The NCAR oxygen instrument (AO2) uses vacuum ultraviolet (VUV) absorption detector also includes an infrared CO2 sensor. VUV has precision 5 seconds ±1.25 meg (1σ) δ(O2/N2), but thermal fractionation...
Abstract The air‐sea exchange of oxygen (O 2 ) is driven by changes in solubility, biological activity, and circulation. total O has been shown to be closely related the heat on seasonal timescales, with ratio flux varying latitude, being higher extratropics lower subtropics. This /heat both a fundamental biogeochemical property convenient metric for testing earth system models. Current estimates rely sparse observations dissolved , leaving it fairly unconstrained. From model ensemble we...
Abstract. We present an evaluation of aircraft observations the carbon and greenhouse gases (CO2, CH4, N2O, CO) using a direct-absorption pulsed quantum cascade laser spectrometer (QCLS) operated during HIPPO CalNex airborne experiments. The QCLS made continuous 1 Hz measurements with 1-sigma Allan precisions 20, 0.5, 0.09, 0.15 ppb for CO2, CO, respectively, over > 500 flight hours on 79 research flights. are compared to two vacuum ultraviolet (VUV) CO instruments (CalNex HIPPO), cavity...
Abstract. Accurate simulation of atmospheric circulation, particularly in the lower stratosphere, is challenging due to unresolved wave-mean flow interactions and limited high-resolution observations for validation. Gravity-induced pressure gradients lead a small but measurable separation heavy light gases by molecular diffusion stratosphere. Because relative abundance Ar N2 exclusively controlled physical transport, argon-to-nitrogen ratio (Ar/N2) provides an additional constraint on...