A robust absorption spectrometer using the off-axis integrated cavity output spectroscopy (ICOS) technique in a passive cavity is presented. The observed sensitivity, conceptually the detection threshold for the absorption cross section (cm2) multiplied by the concentration (cm−3) and normalized by the averaging time, is measured to be 1.9×10−12 (1/cm√Hz). This high sensitivity arises from...
James G. Anderson's Publications
Gregory S. Engel, Walter S. Drisdell, Frank N. Keutsch, Elisabeth J. Moyer, and James G. Anderson, "Ultrasensitive near-infrared integrated cavity output spectroscopy technique for detection of CO at 1.57 μm: new sensitivity limits for absorption measurements in passive optical cavities," Appl. Opt. 45, 9221-9229 (2006)
J. A Dykema and Anderson, J.G. (2006), A methodology for obtaining on-orbit SI-traceable spectral radiance measurements in the thermal infrared, Metrologia, 43, 287-293. doi:10.1088/0026-1394/43/3/011
A methodology to achieve spectral thermal radiance measurements fromspace with demonstrable on-orbit traceability to the International System ofUnits (SI) is described. This technique results in measurements of infraredspectral radiance R(υ )˜ , with spectral index υ˜ in cm−1, with a relativecombined uncertainty uc[R(υ )˜ ] of 0.0015 (k = 1) for the averagemid-infrared radiance emitted by the...
Leroy SS, Dykema JA, Anderson JG (2006) Climate benchmarkingusing GNSS occultation. In: Foelsche et al. (2006b) pp 287–301.doi:10.1007/3-540-34121-8_24
We put climate monitoring in a scientific context, which can be arrived at through a careful implementation of Bayesian inference. What we find is that a good climate monitoring tool must help address the physics of a climate model so as to make it better able to predict future climates. GNSS occultation is ideal because it offers sensitivity to improve the model physics which affects the...
Leroy, S. S., J. G. Anderson, and J. A. Dykema (2006), Testing climate models using GPS radio occultation: A sensitivity analysis,J. Geophys. Res., 111, D17105, doi:10.1029/2005JD006145.
We survey the IPCC AR4 models' responses to SRES A1B forcing in order to evaluate a prediction of climate change common to all models and testable using GPS radio occultation data over the coming decades. Of the IPCC AR4 models that submitted runs of the SRES A1B forcing scenario, we select twelve because of the timeliness of their submission. Trends in the global average surface air temperature...
Wilmouth, D. M., R. M. Stimpfle, J. G. Anderson, J. W. Elkins, D. F. Hurst, R. J. Salawitch, and L. R. Lait (2006), Evolution of inorganic chlorine partitioning in the Arctic polar vortex, J. Geophys. Res., 111, D16308, doi:10.1029/2005JD006951.
The first simultaneous, in situ atmospheric measurements of ClO, ClOOCl, ClONO2, and HCl, which together nearly compose total inorganic chlorine, Cl-y, were obtained using the NASA ER-2 aircraft, deployed from Kiruna, Sweden, during the SOLVE/THESEO mission. These chlorine measurements, along with Cly inferred from in situ measurements of organic chlorine source gases, offer an unprecedented...
Measurements of the Total Water Content of Cirrus Clouds. Part I: Instrument Details and Calibration
Weinstock, E. M., et al. (2006a), Measurements of the total water content ofcirrus clouds. Part I: Instrument details and calibration, J. Atmos. OceanicTechnol., 23, 1397 – 1409, doi:10.1175/JTECH1928.1.
This paper describes an instrument designed to measure the sum of gas phase and solid phase water, or total water, in cirrus clouds, and to be mounted in a pallet in the underbelly of the NASA WB-57 research aircraft. The ice water content of cirrus is determined by subtracting water vapor measured simultaneously by the Harvard water vapor instrument on the aircraft. The total water instrument...
Stimpfle, R. M., D. M. Wilmouth, R. J. Salawitch, and J. G. Anderson, The first measurements of ClOOCl in the stratosphere: The coupling of ClOOCl and ClO in the arctic polar vortex, J. Geophys. Res. 109, D03301, doi:10.1029/2003JD003811, February 4, 2004.
The first measurements of ClOOCl in the stratosphere have been acquired from a NASA ER-2 aircraft, deployed from Kiruna, Sweden (68°N, 21°E), during the joint SOLVE/THESEO-2000 mission of the winter of 1999/2000. ClOOCl is detected by thermal dissociation into two ClO fragments that are measured by the well-known technique of chemical conversion, vacuum ultraviolet resonance fluorescence. Ambient...
Davies, S., M. P. Chipperfield, K. S. Carslaw, B.-M. Sinnhuber, J. G. Anderson, R. M. Stimpfle, D. M. Wilmouth, D. W. Fahey, P. J. Popp, E. C. Richard, P. von der Gathen, H. Jost, and C. R. Webster, Modeling the effect of denitrification on Arctic ozone depletion during winter 1999/2000. J. Geophys. Res., 108(D5), 8322, 2002, doi:10.1029/2001JD000445.
We have used the SLIMCAT three‐dimensional chemical transport model together with observations from the Stratospheric Aerosol and Gas Experiment (SAGE III) Ozone Loss and Validation Experiment (SOLVE) and the Third European Stratospheric Experiment on Ozone (THESEO 2000) to quantify the effect of denitrification on Arctic ozone loss. We have used two different denitrification schemes in the model...
Hanisco, T. F., J. B. Smith, R. M. Stimpfle, D. M. Wilmouth, K. K. Perkins, J. R. Spackman, J. G. Anderson, D. Baumgardner, B. Gandrud, C. R. Webster, S. Dhaniyala, K. A. McKinney, and T. P. Bui, Quantifying the rate of heterogeneous processing in the Arctic polar vortex with in situ observations of OH. J. Geophys. Res., 107(D20), 8278, 2002, doi:10.1029/2001JD000425.
We present simultaneous in situ observations of OH, HO2, ClONO2, HCl, and particle surface area inside a polar stratospheric cloud undergoing rapid heterogeneous processing. A steady‐state analysis constrained by in situ observations is used to show that concentrations of OH calculated during a processing event are extremely sensitive to the assumptions regarding aerosol composition and...
Hanisco, T. F., J. B. Smith, R. M. Stimpfle, D. M. Wilmouth, J. G. Anderson, E. C. Richard, and T. P. Bui, In situ observations of HO2and OH obtained on the NASA ER-2 in the high-ClO conditions of the 1999/2000 Arctic polar vortex. J. Geophys. Res., 107(D20), 8283, 2002, doi:10.1029/2001JD001024.
Extensive observations of OH and HO2 obtained aboard the NASA ER‐2 inside the Arctic polar vortex during the SAGE III Ozone loss and Validation Experiment (SOLVE) provide the opportunity to identify and test interferences during the measurement of HO2 in the presence of high concentrations of ClO. In‐flight calibrations are consistent with small interferences from CH3O2 (8%) and...