ISSN:0148-0227    

DOI:10.1029/JD092iD02p01976

年代:1987

数据来源: WILEY

摘要:

An overview of the airborne intercomparisons of CO, NO, and OH instrumentation is presented in this first paper of the series on the NASA Global Tropospheric Experiment/Chemical Instrumentation Test and Evaluation (GTE/CITE 1). This paper provides the reader with background information about several important characteristics of the project. These include the overall objectives and approach; the measurements taken; the intercomparison protocol, aircraft platform, profiles of each aircraft flight; and the participants. A synopsis of the overall results of the CO, NO, and OH instrument intercomparisons is also included. Companion papers discuss the detailed results of the CO and NO intercomparison tests as well as pertinent scientific findings.

ISSN:0148-0227    

DOI:10.1029/JD092iD02p01977

年代:1987

数据来源: WILEY

摘要:

Meteorological contexts for the NASA GTE/CITE 1 fall 1983 flight series are presented and discussed. The large‐scale wind, cold cloud, and moisture patterns are illustrated by composite diagrams based on the National Oceanic and Atmospheric Administration 700‐, 500‐, and 250‐mbar analyses and the GOES‐West broadband and 6.7‐μm (water vapor) infrared photographs. Detailed flight path diagrams are included for seven maritime flights and one continental flight in the free troposphere and boundary layer. For three flights from Hickam Field, in Honolulu, Hawaii, to the Intertropical Convergence Zone, vertical profiles of temperature, dew/frost point departures, wind velocity, and ozone, and carbon monoxide mixing ratios also are presented and discussed. Excellent agreement is demonstrated between the in situ and remote measurements. In particular, the predictive and diagnostic value of the 6.7‐μm water vapor photographs

ISSN:0148-0227    

DOI:10.1029/JD092iD02p01986

年代:1987

数据来源: WILEY

摘要:

Results from an airborne intercomparison of techniques to measure tropospheric levels of nitric oxide (NO) are discussed. The intercomparison was part of the National Aeronautics and Space Administration's Global Tropospheric Experiment and was conducted during missions flown in the fall of 1983 and spring of 1984. Instruments intercompared included a laser‐induced fluorescence (LIF) system and two chemiluminescence instruments (CL). NO mixing ratios from below 5 pptv (parts per trillion by volume) to greater than 100 pptv were reported, with the majority less than 20 pptv. Good correlation was observed between the measurements reported by the CL and LIF techniques. The general level of agreement observed for the ensemble of measurements obtained during the two missions provides the basis from which one can conclude that equally “valid” measurements of background levels of NO can be expected from either CL or LIF instruments. At the same time the periods of disagreement that were observed between the CL and LIF instruments as well as between the two CL instruments highlight the difficulty of obtaining reliable measurements with NO mixing ratios in the 5–20 pptv range and emphasize the vigilance that should be maintained in future NO measu

ISSN:0148-0227    

DOI:10.1029/JD092iD02p01995

年代:1987

数据来源: WILEY

摘要:

Results from an airborne intercomparison of techniques to measure tropospheric levels of carbon monoxide (CO) are discussed. The intercomparison was conducted as part of the National Aeronautics and Space Administration's Global Tropospheric Experiment and included a laser differential absorption method and two grab sample/gas chromatograph methods. Measurements were obtained during approximately 90 flight hours, during which the CO mixing ratios ranged from about 60 to 140 ppbv. The level of agreement observed for the ensemble of measurements was well within the overall accuracy stated for each instrument. The correlation observed between the measurements from the respective pairs of instruments ranged from 0.85 to 0.98, with no evidence for the presence of either a constant or proportional bias between any of the instruments.

ISSN:0148-0227    

DOI:10.1029/JD092iD02p02009

年代:1987

数据来源: WILEY

摘要:

Airborne measurements of OH were made near the Intertropical Convergence Zone in the Pacific, and the averaged results for each data run were compared with those calculated from a photochemical model. The measured OH concentrations were found to vary along the flight path. Possible causes for the observed variations are discussed.

ISSN:0148-0227    

DOI:10.1029/JD092iD02p02020

年代:1987

数据来源: WILEY

摘要:

Measurements of NO and O3are presented from 13 aircraft flights made over the Pacific Ocean in the autumn of 1983 during one phase of the NASA Global Tropospheric Experiment (GTE). All of the flights were made between 15° and 42°N and from the coast of California to west of the Hawaiian Islands. Within the upper marine boundary layer the median daytime mixing ratio of NO was near 1 part per trillion by volume (pptv). As well, values of NO less than 10 pptv were often observed up to altitudes near 6 km. Thus for the location and season of the measurements, a net photochemical destruction of O3would be anticipated for the boundary layer region and to altitudes of 2–3 km. At higher altitudes of 7–11 km in the free troposphere, larger mixing ratios and greater variability were usually observed for NO. Both features are consistent with observed examples of injection of NO and O3from the lower stratosphere and with the injection of NO from towering, electrically active, cumulonimbus c

ISSN:0148-0227    

DOI:10.1029/JD092iD02p02025

年代:1987

数据来源: WILEY

摘要:

Reported in this paper are the Georgia Institute of Technology NO results from the fall 1983 NASA GTE/CITE 1 Airborne Field Sampling Program. These data were predominantly collected over a geographical area defined by the eastern and central North Pacific Ocean, spanning the latitude range of 15°–42°N. These NO measurements were taken using the two‐photon laser‐induced fluorescence technique. The data show a general trend of increasing levels of NO from the boundary layer up to altitudes of nearly 10 km. The average midday value of No at altitudes of ≤1.8 km was 4 parts per trillion by volume (pptv), and at ∼6 km, 20 pptv, whereas that at ∼9 km was 25–35 pptv, the higher value reflecting the inclusion of NO data collected from the outflow region of two electrically active cumulonimbus clouds. The high‐altitude NO data strongly suggest that at least during the time of the GTE flight operation, the major sources of NO for remote regions of the Pacific Ocean were those resulting from lightning and the downward transport of

ISSN:0148-0227    

DOI:10.1029/JD092iD02p02049

年代:1987

数据来源: WILEY

摘要:

A tunable diode laser instrument denoted as DACOM (Differential Absorption CO Measurement) has been developed to meet the fast‐response, high‐precision CO measurement needs of the GTE (Global Tropospheric Experiment) program. Under the GTE program, DACOM participated in the three field missions of CITE 1 (Chemical Instrumentation Test and Evaluation 1), a project involving the intercomparison of trace gas measurement techniques. DACOM performance, including analyses of measurement error sources, is discussed for the ground‐based mission at Wallops Island, Virginia (summer 1983), and two missions on the NASA CV‐990 (fall 1983 and spring 1984). Examples of fast‐response (≈1 s), high‐precision (±1 part per billion by volume, ±1.5% of reading) airborne data are included to illustrate the capability of

ISSN:0148-0227    

DOI:10.1029/JD092iD02p02071

年代:1987

数据来源: WILEY

摘要:

A set of 14 pairs of vertical profiles of ozone (O3) and carbon monoxide (CO), obtained with fast‐response instrumentation, is presented. Most of these profiles, which were measured in the remote troposphere, also have supporting fast‐response dew‐point temperature profiles. The data suggest that the continental boundary layer is a source of tropospheric ozone, even in October and November, when photochemical activity should be rather small. In general, the small‐scale vertical variability between CO and O3is in phase. At low latitudes this relationship defines levels in the atmosphere where mid‐latitude air is being transported to lower latitudes, since lower dew‐point temperatures accompany these higher CO and O3concentrations. A set of profiles which is suggestive of interhemispheric transport is also presented. Independent meteorological analyses support these inte

ISSN:0148-0227    

DOI:10.1029/JD092iD02p02083

年代:1987

数据来源: WILEY