We present a new instrument, Hoxotope, for the in situ measurement of H2O and its heavy deuterium isotopologue (HDO) in the upper troposphere and lower stratosphere aboard the NASA WB-57. Sensitive measurements of δD are accomplished through the vacuum UV photolysis of water followed by laser-induced fluorescence detection of the resultant OH and OD photofragments....
James G. Anderson's Publications
J.M. St. Clair, T.F. Hanisco, E.M. Weinstock, E.J. Moyer,D.S. Sayres, F.N. Keutsch, J.H. Kroll, J.N. Demusz,N.T. Allen, J.B. Smith, J.R. Spackman, J.G. Anderson, A new photolysis laser-induced fluorescence instrument for the detection of H2O and HDO in the lower stratosphere. Sci. Instrum. 79, 064101 (2008). doi:10.1063/1.2940221.
Sayres, D. S., J. B. Smith, J. V. Pittman, E. M. Weinstock, J. G. Anderson, G. Heymsfield, L. Li, A. M. Fridlind, and A. S. Ackerman(2008), Validation and determination of ice water content-radar reflectivity relationships during CRYSTAL-FACE: Flight requirements for future comparisons, J. Geophys. Res., 113, D05208, doi:10.1029/2007JD008847.
In situ measurements of cirrus ice water content (IWC) by the Harvard water vapor and total water instruments during Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment are compared with remote sensing data made by the Cloud Radar System instrument in order to derive and validate an empirical IWC-radar relflectivity Z e relationship. The...
Leroy, S. S., J. G. Anderson, and G. Ohring (2008), Climate signal detection times and constraints on climate benchmark accuracy requirements,J. Clim., 21, 841 – 846, doi:10.1175/2007JCLI1946.1.
Long term trends in the climate system are always partly obscured by naturally occurring interannual variability.All else being equal, the larger the natural variability is, the less precisely one can estimate a trend in a timeseriesof data. Measurement uncertainty, though, also obscures long term trends. We derive how measurement uncertaintyand natural interannual variability interact in...
Leroy, Stephen, James Anderson, John Dykema, Richard Goody, 2008: Testing Climate Models Using Thermal Infrared Spectra. J. Climate, 21, 1863–1875. doi: http://dx.doi.org/10.1175/2007JCLI2061.1
An approach to test climate models with observations is presented. In this approach, it is possible to directly observe the longwave feedbacks of the climate system in time series of annual average outgoing longwave spectra. Tropospheric temperature, stratospheric temperature, water vapor, and carbon dioxide have clear and distinctive signatures in the infrared spectrum, and it is possible to...
Weinstock, E. M., et al. (2007), Quantifying the impact of the North American monsoon and deep midlatitude convection on the subtropical lowermost stratosphere using in situ measurements, J. Geophys. Res., 112, D18310, doi:10.1029/2007JD008554.
The chemical composition of the lowermost stratosphere exhibits both spatial and temporal variability depending upon the relative strength of (1) isentropic transport from the tropical tropopause layer (TTL), (2) diabatic descent from the midlatitude and northern midlatitude stratosphere followed by equatorward isentropic transport, and (3) diabatic ascent from the troposphere through convection...
Leroy, S. S., and J. G. Anderson (2007), Estimating Eliassen-Palm flux using COSMIC radio occultation, Geophys. Res. Lett.,34, L10810, doi:10.1029/2006GL028263.
We present a methodology for analyzing the Eliassen-Palm (E-P) flux in the troposphere and stratosphere using GPS radio occultation data from the COSMIC project. In this methodology, geopotential height and temperature are mapped on constant pressure surfaces using a Bayesian interpolation scheme with a spherical harmonic basis, and the components of the E-P flux are evaluated using geostrophic...
Pittman, J. V., et al. (2007), Transport in the subtropical lowermost stratosphere during the Cirrus Regional Study ofTropical Anvils and Cirrus Layers – Florida Area Cirrus Experiment, J. Geophys. Res., 112, D08304, doi:10.1029/2006JD007851.
We use in situ measurements of water vapor (H2O), ozone (O3), carbon dioxide(CO2), carbon monoxide (CO), nitric oxide (NO), and total reactive nitrogen (NOy)obtained during the CRYSTAL-FACE campaign in July 2002 to study summertimetransport in the subtropical lowermost stratosphere. We use an objective methodology todistinguish the latitudinal origin of the sampled air masses despite the...
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.
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...
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...