Publications

Leroy, S.S., J.A. Dykema, and J.G. Anderson, “Scalar prediction in climate using data and model,” Submitted to J. Climate (2008).

Scalar detection in climate change research, having taken the form of optimal detection/linear multi-pattern regression, has been used in the recent past to detect multiple climate signals in the presence of natural inter- annual variability and associate those signals with specific causes. It has been applied to many climate observables to show high probabilities of human influence on climatic...

Gero P J, Dykema J A and Anderson J G 2008 A blackbody design for SI-traceable radiometry for earth observation J. Atmos. Ocean. Technol. 25 2046–54

Spaceborne measurements pinned to international standards are needed to monitor the earth’s climate,quantify human influence thereon, and test forecasts of future climate change. The International System ofUnits (SI, from the French for Système International d’Unités) provides ideal measurement standards forradiometry as they can be realized anywhere, at any time in the future. The challenge is...

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 occultationGeophys. 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 compositionGeophys. 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...

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...

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