@article{newell_zhu_connors_reichle_novelli_gormsen_1999, title={Atmospheric processes influencing measured carbon monoxide in the NASA Measurement of Air Pollution From Satellites (MAPS) experiment}, volume={104}, ISSN={["2169-8996"]}, DOI={10.1029/1999JD900394}, abstractNote={The Measurement of Air Pollution From Satellites (MAPS) experiment measured global distributions of carbon monoxide (CO) while on board the space shuttle during April 9–19 and September 30 to October 11, 1994. This paper examines selected examples of the meteorological processes that contributed to the observed signals. We first examine and relate the mean distribution of MAPS‐measured CO, surface station‐measured CO, streamlines, and divergent winds averaged over the two missions. Tropical high CO values were associated with boundary layer convergence regions, particularly in October, that enable CO associated with biomass burning to reach the free troposphere where it can be detected by the nadir viewing gas filter 4.7 μm radiometer. CO values over northern middle latitudes show evidence of fossil fuel pollution especially in April. Southern middle and high latitudes in April suggest photochemical control, while in October these regions are strongly influenced by the tropical biomass burning. Next, we consider events on 1 day near the center of each mission and show that in one of these cases, low CO measurements are associated with high potential vorticity, which suggests that the air samples originated from the stratosphere. Finally, we modify the two mean patterns, both within 23 days of the equinox, to illustrate the possible separation of the natural photochemical CO pattern from the CO pollution patterns. This procedure brings out the intercontinental and transcontinental transport of pollution in April northern hemisphere middle and high latitudes as well as, less markedly, in the October maps. It also accentuates the biomass burning contribution in October and shows pollution to extend southeastward from South America into the South Atlantic and also from Australia into the South Pacific. The separation is made possible by having CO measurements with global coverage.}, number={D17}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Newell, RE and Zhu, Y and Connors, VS and Reichle, HG and Novelli, PC and Gormsen, BB}, year={1999}, month={Sep}, pages={21487–21501} }
 @article{pougatchev_sachse_fuelberg_rinsland_chatfield_connors_jones_notholt_novelli_reichle_1999, title={Pacific Exploratory Mission-Tropics carbon monoxide measurements in historical context}, volume={104}, ISSN={["2169-8996"]}, DOI={10.1029/1999JD900465}, abstractNote={The three‐dimensional (3‐D) distribution of carbon monoxide (CO) over the southern Pacific during the NASA Global Tropospheric Experiment Pacific Exploratory Mission‐Tropics (PEM‐T) (August‐October 1996) has been analyzed in comparison to other CO measurements. The following data sets have been used in the study: National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostic Laboratory surface level sampling; Commonwealth Scientific and Industrial Research Organization aircraft measurements over Cape Grim, Tasmania; solar spectroscopic measurements at Lauder, New Zealand; and data from two spaceborne Measurement of Air Pollution From Satellite experiments. For the PEM‐T mission back trajectories analysis and 3‐D modeling of the CO transport have been performed. It has been demonstrated that CO measurements obtained by different in situ and remote techniques can be used to build the picture of the CO climatology over the large geographical area. The structure of the CO distribution over the western part of the southern Pacific during the austral spring is mainly controlled by emission from biomass burning in Australia and Africa and subsequent long‐range transport. The prevailing westerly transport occurs in the middle and upper troposphere, whereas the marine boundary layer remains relatively clean and uniform. Barriers in the form of the Intertropical Convergence Zone and South Pacific Convergence Zone protect the equatorial area (equator to 10°S) from direct impact of biomass burning plumes from north and southwest. Consistency between the measurements taken in different years and modeling results indicates that the observed feature is a stable phenomenon. Outside the equatorial area the CO vertical distribution has a broad distinctive maximum at the altitude range 5–8 km and latitudes between 20°S and 30°S. This maximum is a stable feature, and its location indicates the area where the most intensive westerly transport occurs.}, number={D21}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Pougatchev, NS and Sachse, GW and Fuelberg, HE and Rinsland, CP and Chatfield, RB and Connors, VS and Jones, NB and Notholt, J and Novelli, PC and Reichle, HG}, year={1999}, month={Nov}, pages={26195–26207} }
 @article{faluvegi_alapaty_reichle_mathur_raman_connors_1999, title={Simulation of carbon monoxide transport during April 1994}, volume={104}, ISSN={["2169-8996"]}, DOI={10.1029/1998JD100030}, abstractNote={The Multiscale Air Quality Simulation Platform (MAQSIP) is used to simulate transport of carbon monoxide (CO) as a passive tracer over North America, Europe, and the North Atlantic during the April 1994 Measurement of Air Pollution from Satellites (MAPS) mission. MAQSIP is driven by meteorological fields generated by the Pennsylvania State University/National Center for Atmospheric Research fifth‐generation mesoscale model. Model CO surface emissions from biomass burning, fossil fuel combustion, nonmethane hydrocarbon oxidation, oceans, and soils are based on inventories from the Belgian Institute for Space Aeronomy and the Global Emissions Inventory Activity. Predicted CO mixing ratios are vertically weighted for comparison with MAPS observations. The spread in the mission‐averaged vertically weighted simulated CO mixing ratios (∼38 ppbv, compared to 60 ppbv in the MAPS data) suggests that CO surface emissions significantly affect MAPS observations on a weekly timescale. Good qualitative agreement is found between MAPS observations and model predictions on several temporal and spatial scales. Possible reasons for discrepancies are examined. A simulation without cumulus convection increases CO mixing ratios in the lower model layers and depletes CO above, resulting in a complex pattern of increases and decreases upon vertical weighted integration. Another simulation, which included a diurnal emissions variation, produced significant changes in instantaneous local CO mixing ratios, but had a minimal effect on the mission‐averaged MAPS comparisons.}, number={D17}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Faluvegi, GS and Alapaty, K and Reichle, HG and Mathur, R and Raman, S and Connors, VS}, year={1999}, month={Sep}, pages={21471–21485} }
 @article{reichle_anderson_connors_denkins_forbes_gormsen_langenfelds_neil_nolf_novelli_et al._1999, title={Space shuttle based global CO measurements during April and October 1994, MAPS instrument, data reduction, and data validation}, volume={104}, ISSN={["2169-8996"]}, DOI={10.1029/97JD03299}, abstractNote={The Measurement of Air Pollution From Satellites (MAPS) experiment flew as a payload aboard the space shuttle during April and October 1994. The instrument and the data reduction procedure were modified from earlier flights in 1981 and 1984. The modifications to both are described, and selected portions of the data are compared to concurrent aircraft borne direct measurements that had been carefully intercalibrated. In addition, the data acquired in 1984 were reprocessed using the new data reduction procedure, and the reprocessed data were compared to aircraft data acquired in 1984. The results of these comparisons indicate that the large bias error in the 1984 MAPS data has been reduced to about 10%.}, number={D17}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Reichle, HG and Anderson, BE and Connors, VS and Denkins, TC and Forbes, DA and Gormsen, BB and Langenfelds, RL and Neil, DO and Nolf, SR and Novelli, PC and et al.}, year={1999}, month={Sep}, pages={21443–21454} }
 @article{connors_gormsen_nolf_reichle_1999, title={Spaceborne observations of the global distribution of carbon monoxide in the middle troposphere during April and October 1994}, volume={104}, ISSN={["2169-8996"]}, DOI={10.1029/1998JD100085}, abstractNote={Spaceborne measurements of tropospheric carbon monoxide (CO) were made by the Measurement of Air Pollution from Satellites (MAPS) experiment during April 9–19, 1994, and September 30 to October 11, 1994, from the space shuttle Endeavour. During the April mission, MAPS operated for 211 hours, with 736,471 s of nadir‐viewing data, of which 161,619 s were cloud‐free. In the October mission, MAPS operated for 256 hours, with 821,502 s of nadir‐viewing data, of which 192,004 s were cloud‐free. During the two 10‐day Space Radar Laboratory flights, extensive and internally consistent correlative measurements and observations were made on the ground at nearly 30 sites between 70°N and 67°S, from five aircraft in three countries, and by the astronaut crews from the space shuttle. These ancillary measurements provided critical information on the nature of the atmospheric environment during the flights, the distribution of the CO mixing ratios in the boundary layer and in the middle troposphere, and the vertical distribution of CO at some locations. Although the airborne CO measurements are the key validation data sets for the MAPS measurements, the ground‐based CO measurements provide a near‐surface CO boundary condition for modeling applications and for CO emissions investigations. This paper will present the measurements of the April and October 1994 and the October 1984 MAPS CO data. These MAPS results compare well (±10%) with the intercalibrated airborne measurements from the NASA DC‐8 flights over North America, and CO profiles from the Commonwealth Scientific and Industrial Research Organisation aircraft near Cape Grim, Tasmania. Longitudinal and latitudinal transects of the MAPS CO measurements show significant seasonal variability consistent with the seasonal shifts in the locations and strengths of the CO sources. In April the highest average CO values (∼120 ppbv, averaged throughout the depth of the atmosphere) are found over the high northern latitudes, with decreasing amounts (∼45 to 60 ppbv) toward the southern middle and high latitudes. The CO distribution changed dramatically by October with the CO gradient being reversed from that measured during April. During October the highest CO values (greater than 135 ppbv) are concentrated in a tropical envelope extending over central South America, southern Africa, southern India, Indonesia, and northern Australia. Numerous and extensive fires in these areas were observed and photographed by the STS 68 astronaut flight crew.}, number={D17}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Connors, VS and Gormsen, BB and Nolf, S and Reichle, HG}, year={1999}, month={Sep}, pages={21455–21470} }
 @article{reichle_connors_1999, title={The mass of CO in the atmosphere during October 1984, April 1994, and October 1994}, volume={56}, ISSN={["0022-4928"]}, DOI={10.1175/1520-0469(1999)056<0307:TMOCIT>2.0.CO;2}, abstractNote={Abstract The latitudinal distribution and the total mass of CO in the atmosphere are calculated for October 1984, April 1994, and October 1994 based upon measurements made by the MAPS experiment aboard the space shuttle. It is shown that the amount of CO in October 1994 was greater than in October 1984 and that this increase was dominated by increases in the tropical regions, particularly in the region north and northwest of Australia.}, number={2}, journal={JOURNAL OF THE ATMOSPHERIC SCIENCES}, author={Reichle, HG and Connors, VS}, year={1999}, month={Jan}, pages={307–310} }
 @article{doddridge_morales-morales_rhoads_merrill_novelli_dickerson_connors_reichle_1998, title={Ground-based and airborne observations of carbon monoxide during NASA measurements of air pollution from satellite (MAPS) missions SRL-1 and SRL-2}, volume={103}, ISSN={["2169-8996"]}, DOI={10.1029/97JD01837}, abstractNote={Surface carbon monoxide (CO) data were acquired continuously at Heimaey, Iceland (63°24′N, 20° 18′W), Mace Head, Ireland (53° 19′N, 9°54′W), and Ragged Point, Barbados (13°15′N, 59°30′W), during April and October 1994, in support of Measurement of Air Pollution From Satellite (MAPS) Space Radar Laboratory (SRL) missions SRL‐1 and SRL‐2, respectively, measuring middle tropospheric CO from space. Observed median CO levels from the three surface sites during these two MAPS missions approximate the monthly median for 1994 and are mostly typical of data from prior years. For two of the sites, computed mission isentropic back‐trajectory ensemble probability fields are compared to seasonal (March‐May and September‐November) probability fields for 1994 and 1986–1995. Such comparisons help gauge the representativeness of (1) observed surface air quality at, and (2) isentropic flow to, these sites during the mission periods, in terms of intraseasonal and interannual variability. Results appear consistent with longer‐term flow climatological data and confirm the SRL‐1 and SRL‐2 mission periods are generally representative of the climatology applicable to these sites for the time of year. Lower free troposphere in situ CO data were acquired from an aircraft over the Maryland Eastern Shore on April 14 and October 3, 4, and 6. During the April flight a nearly linear gradient in CO with pressure from 1000–650 mbar of 225‐150 parts per billion by volume (ppbv) was observed. At 650 mbar, CO was quite steady around 150 ppbv; this value compares favorably with the MAPS CO data for the closest 5° ×; 5° grid box averaged April 13–15 of 105–120 ppbv. During SRL‐2 a three flight CO average of 125 ppbv observed at ∼725 mbar is in good agreement with the closest MAPS 5° × 5° grid box averaged October 3–7 of 90–105 ppbv. A layer of elevated CO at 845–740 mbar, most likely the result of synoptic‐scale transport, was observed during the October flights and seen to dissipate with time. The MAPS cloud‐filtered second‐by‐second CO data during concurrent shuttle overflights show temporal structure consistent with the in situ observations, indicating the MAPS weighting function may be capable of discerning features at lower altitudes than thought previously.}, number={D15}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Doddridge, BG and Morales-Morales, R and Rhoads, KP and Merrill, JT and Novelli, PC and Dickerson, RR and Connors, VS and Reichle, HG}, year={1998}, month={Aug}, pages={19305–19316} }
 @article{pougatchev_jones_connor_rinsland_becker_coffey_connors_demoulin_dzhola_fast_et al._1998, title={Ground-based infrared solar spectroscopic measurements of carbon monoxide during 1994 Measurement of Air Pollution From Space flights}, volume={103}, ISSN={["2169-897X"]}, DOI={10.1029/97JD02889}, abstractNote={Results of the comparison of carbon monoxide ground‐based infrared solar spectroscopic measurements with data obtained during 1994 Measurement of Air Pollution From Space (MAPS) flights are presented. Spectroscopic measurements were performed correlatively with April and October MAPS flights by nine research groups from Belgium, Canada, Germany, Japan, New Zealand, Russia, and the United States. Characterization of the techniques and error analysis were performed. The role of the CO a priori profile used in the retrieval was estimated. In most cases an agreement between spectroscopic and MAPS data is within estimated MAPS accuracy of ±10%.}, number={D15}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Pougatchev, NS and Jones, NB and Connor, BJ and Rinsland, CP and Becker, E and Coffey, MT and Connors, VS and Demoulin, P and Dzhola, AV and Fast, H and et al.}, year={1998}, month={Aug}, pages={19317–19325} }
 @article{reichle_connors_olson_thompson_1998, title={MAPS - Preface}, volume={103}, ISSN={["2169-8996"]}, DOI={10.1029/98JD01108}, abstractNote={Journal of Geophysical Research: AtmospheresVolume 103, Issue D15 p. 19283-19284 Free Access Preface [to special section on MAPS] Henry G. Reichle Jr., Henry G. Reichle Jr.Search for more papers by this authorVickie S. Connors, Vickie S. ConnorsSearch for more papers by this authorJennifer Olson, Jennifer OlsonSearch for more papers by this authorAnne Thompson Olson, Anne Thompson OlsonSearch for more papers by this author Henry G. Reichle Jr., Henry G. Reichle Jr.Search for more papers by this authorVickie S. Connors, Vickie S. ConnorsSearch for more papers by this authorJennifer Olson, Jennifer OlsonSearch for more papers by this authorAnne Thompson Olson, Anne Thompson OlsonSearch for more papers by this author First published: 01 August 1998 https://doi.org/10.1029/98JD01108Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References Brasseur, G., S. Solomon, Aeronomy of the Middle Atmosphere 2nd ed., 452, D. Reidel, Norwell, Mass., 1986. Christopher, S. A., D. V. Kliche, R. M. Welch, andV. S. 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Novelli, Total column and surface densities of atmospheric carbon monoxide in Alaska, 1995,J. Geophys. Res., 103(D15), 1998. Zimmerman, P. R., R. B. Chatfield, J. Fishman, P. J. Crutzen, P. L. Hanst, Estimates on the production of CO and H2 from the oxidation of hydrocarbon emissions from vegetation, Geophys. Res. Lett., 5, 679, 1978. Citing Literature Volume103, IssueD1520 August 1998Pages 19283-19284 This article also appears in:MAPS ReferencesRelatedInformation}, number={D15}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Reichle, HG and Connors, VS and Olson, J and Thompson, A}, year={1998}, month={Aug}, pages={19283–19284} }
 @article{queen_easterling_connors_1998, title={Teaching young researchers GIS: From wetlands to the Web}, volume={8}, number={3}, journal={Geo Info Systems}, author={Queen, A. M. and Easterling, H. and Connors, V. S.}, year={1998}, pages={38-} }