Search Results - "Langford, A. O."

Stratospheric influence on surface ozone in the Los Angeles area during late spring and early summer of 2010 by Langford, A. O., Brioude, J., Cooper, O. R., Senff, C. J., Alvarez II, R. J., Hardesty, R. M., Johnson, B. J., Oltmans, S. J.

“…The influence of stratosphere‐to‐troposphere transport (STT) on surface ozone (O3) concentrations in the greater Los Angeles area during the CalNex and…”
Get full text

Single-particle measurements of midlatitude black carbon and light-scattering aerosols from the boundary layer to the lower stratosphere by Schwarz, J. P., Gao, R. S., Fahey, D. W., Thomson, D. S., Watts, L. A., Wilson, J. C., Reeves, J. M., Darbeheshti, M., Baumgardner, D. G., Kok, G. L., Chung, S. H., Schulz, M., Hendricks, J., Lauer, A., Kärcher, B., Slowik, J. G., Rosenlof, K. H., Thompson, T. L., Langford, A. O., Loewenstein, M., Aikin, K. C.

“…A single-particle soot photometer (SP2) was flown on a NASA WB-57F high-altitude research aircraft in November 2004 from Houston, Texas. The SP2 uses…”
Get full text

A broadband cavity enhanced absorption spectrometer for aircraft measurements of glyoxal, methylglyoxal, nitrous acid, nitrogen dioxide, and water vapor by Min, K.-E, Washenfelder, R. A, Dubé, W. P, Langford, A. O, Edwards, P. M, Zarzana, K. J, Stutz, J, Lu, K, Rohrer, F, Zhang, Y, Brown, S. S

“…We describe a two-channel broadband cavity enhanced absorption spectrometer (BBCEAS) for aircraft measurements of glyoxal (CHOCHO), methylglyoxal (CH3COCHO),…”
Get full text

Stratospheric intrusions, the Santa Ana winds, and wildland fires in Southern California by Langford, A. O., Pierce, R. B., Schultz, P. J.

“…The Santa Ana winds of Southern California have long been associated with wildland fires that can adversely affect air quality and lead to loss of life and…”
Get full text

Stratospheric contribution to high surface ozone in Colorado during springtime by Langford, A. O., Aikin, K. C., Eubank, C. S., Williams, E. J.

“…The contribution of stratosphere‐to‐troposphere transport to high surface ozone (O3) along the Colorado Front Range during spring of 1999 is examined using…”
Get full text

Entrainment of stratospheric air and Asian pollution by the convective boundary layer in the southwestern U.S by Langford, A. O., Alvarez, R. J., Brioude, J., Fine, R., Gustin, M. S, Lin, M. Y., Marchbanks, R. D., Pierce, R. B., Sandberg, S. P., Senff, C. J., Weickmann, A. M., Williams, E. J.

“…A series of deep stratospheric intrusions in late May 2013 increased the daily maximum 8 h surface ozone (O3) concentrations to more than 70 parts per billion…”
Get full text

The 2010 California Research at the Nexus of Air Quality and Climate Change (CalNex) field study by Ryerson, T. B., Andrews, A. E., Angevine, W. M., Bates, T. S., Brock, C. A., Cairns, B., Cohen, R. C., Cooper, O. R., de Gouw, J. A., Fehsenfeld, F. C., Ferrare, R. A., Fischer, M. L., Flagan, R. C., Goldstein, A. H., Hair, J. W., Hardesty, R. M., Hostetler, C. A., Jimenez, J. L., Langford, A. O., McCauley, E., McKeen, S. A., Molina, L. T., Nenes, A., Oltmans, S. J., Parrish, D. D., Pederson, J. R., Pierce, R. B., Prather, K., Quinn, P. K., Seinfeld, J. H., Senff, C. J., Sorooshian, A., Stutz, J., Surratt, J. D., Trainer, M., Volkamer, R., Williams, E. J., Wofsy, S. C.

“…The California Research at the Nexus of Air Quality and Climate Change (CalNex) field study was conducted throughout California in May, June, and July of 2010…”
Get full text

Airborne lidar measurements of ozone flux downwind of Houston and Dallas by Senff, C. J., Alvarez II, R. J., Hardesty, R. M., Banta, R. M., Langford, A. O.

“…We use airborne lidar measurements of ozone collected during the Texas Air Quality Study (TexAQS) 2000 and TexAQS 2006 field campaigns to compute the…”
Get full text

Convective venting and surface ozone in Houston during TexAQS 2006 by Langford, A. O., Tucker, S. C., Senff, C. J., Banta, R. M., Brewer, W. A., Alvarez II, R. J., Hardesty, R. M., Lerner, B. M., Williams, E. J.

“…The influence of convective mixing on surface ozone in Houston during TexAQS 2006 is examined. We use airborne lidar measurements of ozone and ship‐based…”
Get full text

Stratosphere-troposphere exchange at the subtropical jet: Contribution to the tropospheric ozone budget at midlatitudes by Langford, A. O.

“…The interannual variability of the springtime maximum in free tropospheric ozone above Colorado is examined using 5‐1/2 years (1993–1998) of Differential…”
Get full text

Measurement of glyoxal using an incoherent broadband cavity enhanced absorption spectrometer by Washenfelder, R. A., Langford, A. O., Fuchs, H., Brown, S. S.

“…We describe an instrument for simultaneous measurements of glyoxal (CHOCHO) and nitrogen dioxide (NO2) using cavity enhanced absorption spectroscopy with a…”
Get full text

On the variability of the Ring effect in the near ultraviolet: understanding the role of aerosols and multiple scattering by Langford, A. O., Schofield, R., Daniel, J. S., Portmann, R. W., Melamed, M. L., Miller, H. L., Dutton, E. G., Solomon, S.

“…The "filling-in" (FI) of Fraunhofer lines, often referred to as the Ring effect, was examined using measurements of near ultraviolet sunlight scattered from…”
Get full text

Using Ozone Lidar to Investigate Sources of High Ozone Concentrations in the Western United States by Senff, C. J., Langford, A. O., Alvarez, R. J., Brewer, Wm. A., Banta, R. M., Marchbanks, R. D., Sandberg, S. P., Weickmann, A. M., Holloway, J. S., Williams, E. J.

“…We have used NOAA’s Tunable Optical Profiler for Aerosol and oZone (TOPAZ) ozone lidar to investigate the sources of high surface ozone concentrations in two…”
Get full text

An overview of the 2013 Las Vegas Ozone Study (LVOS): Impact of stratospheric intrusions and long-range transport on surface air quality by Langford, A.O., Senff, C.J., Alvarez, R.J., Brioude, J., Cooper, O.R., Holloway, J.S., Lin, M.Y., Marchbanks, R.D., Pierce, R.B., Sandberg, S.P., Weickmann, A.M., Williams, E.J.

“…The 2013 Las Vegas Ozone Study (LVOS) was conducted in the late spring and early summer of 2013 to assess the seasonal contribution of…”
Get full text

Sulfur dioxide emission flux measurements from point sources using airborne near ultraviolet spectroscopy during the New England Air Quality Study 2004 by Melamed, M. L., Langford, A. O., Daniel, J. S., Portmann, R. W., Miller, H. L., Eubank, C. S., Schofield, R., Holloway, J., Solomon, S.

“…This work presents measurements of sulfur dioxide (SO2) emission fluxes from point sources using airborne near‐ultraviolet (UV) spectroscopy. A Czerny‐Turner…”
Get full text

Weakening of the weekend ozone effect over California's South Coast Air Basin by Baidar, S., Hardesty, R. M., Kim, S.-W., Langford, A. O., Oetjen, H., Senff, C. J., Trainer, M., Volkamer, R.

“…We have observed lower nitrogen dioxide (NO2) and ozone (O3) during a hot weekend (summer 2010) from aircraft over the entire South Coast Air Basin (SoCAB)…”
Get full text

Field measurements of water vapor continuum absorption in the visible and near-infrared by Sierk, B., Solomon, S., Daniel, J. S., Portmann, R. W., Gutman, S. I., Langford, A. O., Eubank, C. S., Dutton, E. G., Holub, K. H.

“…We carried out a spectroscopic field experiment designed to measure water vapor continuum absorption in the visible and near‐infrared spectral regions…”
Get full text

Spectroscopic measurements of NO2 in a Colorado thunderstorm: Determination of the mean production by cloud-to-ground lightning flashes by Langford, A. O., Portmann, R. W., Daniel, J. S., Miller, H. L., Solomon, S.

“…Ground‐based visible absorption spectroscopy of zenith‐scattered sky light was used to measure changes in the column abundance of NO2 during the passage of a…”
Get full text

Dissipation and mixing of a small-scale stratospheric intrusion in the upper troposphere by Langford, A. O., Reid, S. J.

“…Ground‐based lidar measurements of ozone mixing ratio and aerosol backscatter profiles above Fritz Peak Observatory near Boulder, Colorado (39.9° N, 105.3°W),…”
Get full text

Retrieval of ice crystal effective diameters from ground-based near-infrared spectra of optically thin cirrus by Langford, A. O., Portmann, R. W., Daniel, J. S., Miller, H. L., Eubank, C. S., Solomon, S., Dutton, E. G.

“…The microphysical properties of an optically thin (τ ≤ 0.12) cirrus layer formed by dispersing contrails above Boulder, Colorado, have been examined in a…”
Get full text