In situ observations of H2O and HDO in the midlatitude stratosphere are used to evaluate the role of convection in determining the stratospheric water budget. The observations show that water vapor in the overworld stratosphere (potential temperature > 380 K) is isotopically heavier than expected. Measurements in an airmass with anomalously high concentrations of water vapor show isotopic...
Publications
Hanisco, T. F., et al. (2007), Observations of deep convective influence on stratospheric water vapor and its isotopic composition, Geophys. Res. Lett., 34, L04814, doi:10.1029/2006GL027899.
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...
Revercomb, H. E., Anderson, J. G., Best, F. A., Tobin, D. C., Knuteson, R. O., LaPorte, D.D., and Taylor, J. K.: Infrared calibration for climate: A perspective on present and future high spectral resolution instruments, Multispectral, Hyperspectral, and Ultraspectral RemoteSensing Technology, Techniques, and Applications, Gao, India, 13–16 November 2006.
The new era of high spectral resolution infrared instruments for atmospheric sounding offers great opportunities for climate change applications. A major issue with most of our existing IR observations from space is spectral sampling uncertainty and the lack of standardization in spectral sampling. The new ultra resolution observing capabilities from the AIRS grating...
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)
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...
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...
Canty, T., E. D. Rivière, R. J. Salawitch, G. Berthet, J. -B. Renard, K. Pfeilsticker, M. Dorf, A. Butz, H. Bösch, R. M. Stimpfle, D. M. Wilmouth, E. C. Richard, D. W. Fahey, P. J. Popp, M. R. Schoeberl, L. R. Lait, and T. P. Bui, Nighttime OClO in the winter Arctic vortex. J. Geophys. Res., 110, D01301, 2005, doi:10.1029/2004JD005035.
We show that a nighttime profile of OClO in the Arctic vortex during the winter of 2000 is overestimated, by nearly a factor of 2, using an isentropic trajectory model constrained by observed profiles of ClOx (ClO + 2 × ClOOCl) and BrO. Calculated abundances of nighttime OClO are shown to be sensitive to the abundance of BrOx (BrO + BrCl), details of the air parcel history during the...
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...