%0 Journal Article %1 Crawford2004 %A Crawford, J. H. %A Heald, C. L. %A Fuelberg, H. E. %A Morse, D. M. %A Sachse, G. W. %A Emmons, L. K. %A Gille, J. C. %A Edward, D. P. %A Deeter, M. N. %A Chen, G. %A Olson, J. R. %A Connors, V. S. %A Kittaka, C. %A Hamlin, A. J. %D 2004 %I Amer Geophysical Union %J Journal of Geophysical Research-Atmospheres %K PACIFICEXPLORATORYMISSION;CARBON-MONOXIDE;INSTRUMENT;SATELLITE;OZONE;AIRCRAFT;PERIOD %N D15 %P D15S04 %R 10.1029/2003JD004308 %T Relationship between Measurements of Pollution in the Troposphere (MOPITT) and in situ observations of CO based on a large-scale feature sampled during TRACE-P %V 109 %X During Transport and Chemical Evolution over the Pacific (TRACE-P), there were several opportunities to perform in situ sampling coincident with overpasses of the Measurements of Pollution in the Troposphere (MOPITT) instrument on board the EOS Terra satellite. This sampling consisted of in situ vertical profiles of CO by NASA's DC-8 aircraft intended to provide data useful for validating MOPITT observations of CO column. One particular profile conducted over the central North Pacific revealed a layer of pollution characterized by CO mixing ratios more than double background values. Sampling of the surrounding region by both the NASA DC-8 and P-3B aircraft showed this layer to have a considerable geographic extent, at least 25degrees longitude (similar to2500 km) and 4degrees latitude (similar to400 km). Using back trajectory analysis, this polluted layer is followed back in time and compared with four consecutive MOPITT overpasses. MOPITT observations during these four overpasses agree well with the location of the layer as inferred by the trajectories; however, the detected CO column amount increases backward in time by just over 20%. Further analysis shows that the majority of this change in detected column abundance is consistent with two factors: ( 1) changes in the thickness of the polluted layer over time (9 +/- 3%) and (2) changes in retrieved column abundance due to the altitude of the layer (7 +/- 3%). This demonstrates that there are both real and artificial sources of variability that must be understood before MOPITT observations can be quantitatively useful. An unexpected finding was the difference in the variance of MOPITT observations depending on whether observations were taken under daylight or nighttime conditions. The variance in daytime observations of the polluted layer was approximately double that for nighttime data. The results of this analysis indicate that targeted in situ sampling of large-scale pollution events can provide insight leading to more realistic interpretation of MOPITT observations. Strategies for sampling such events repeatedly during their evolution could also provide more interesting opportunities for validation.

@article{Crawford2004, abstract = {During Transport and Chemical Evolution over the Pacific (TRACE-P), there were several opportunities to perform in situ sampling coincident with overpasses of the Measurements of Pollution in the Troposphere (MOPITT) instrument on board the EOS Terra satellite. This sampling consisted of in situ vertical profiles of CO by NASA's DC-8 aircraft intended to provide data useful for validating MOPITT observations of CO column. One particular profile conducted over the central North Pacific revealed a layer of pollution characterized by CO mixing ratios more than double background values. Sampling of the surrounding region by both the NASA DC-8 and P-3B aircraft showed this layer to have a considerable geographic extent, at least 25degrees longitude (similar to2500 km) and 4degrees latitude (similar to400 km). Using back trajectory analysis, this polluted layer is followed back in time and compared with four consecutive MOPITT overpasses. MOPITT observations during these four overpasses agree well with the location of the layer as inferred by the trajectories; however, the detected CO column amount increases backward in time by just over 20%. Further analysis shows that the majority of this change in detected column abundance is consistent with two factors: ( 1) changes in the thickness of the polluted layer over time (9 +/- 3%) and (2) changes in retrieved column abundance due to the altitude of the layer (7 +/- 3%). This demonstrates that there are both real and artificial sources of variability that must be understood before MOPITT observations can be quantitatively useful. An unexpected finding was the difference in the variance of MOPITT observations depending on whether observations were taken under daylight or nighttime conditions. The variance in daytime observations of the polluted layer was approximately double that for nighttime data. The results of this analysis indicate that targeted in situ sampling of large-scale pollution events can provide insight leading to more realistic interpretation of MOPITT observations. Strategies for sampling such events repeatedly during their evolution could also provide more interesting opportunities for validation.}, added-at = {2009-06-08T21:15:51.000+0200}, author = {Crawford, J. H. and Heald, C. L. and Fuelberg, H. E. and Morse, D. M. and Sachse, G. W. and Emmons, L. K. and Gille, J. C. and Edward, D. P. and Deeter, M. N. and Chen, G. and Olson, J. R. and Connors, V. S. and Kittaka, C. and Hamlin, A. J.}, biburl = {https://www.bibsonomy.org/bibtex/26a0909584e5eac69538b35c3f7421c35/claas}, c1 = {NASA, Langley Res Ctr, Hampton, VA 23681 USA.EOLEOLHarvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA.EOLEOLFlorida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA.EOLEOLNatl Ctr Atmospher Res, Boulder, CO 80307 USA.}, citedreferences = {*ECMWF, 1995, MET B M, V32 ; BENGTSSON L, 1985, B AM METEOROL SOC, V66, P1133 ; DEETER MN, 2002, J ATMOS OCEAN TECH, V19, P1772 ; DEETER MN, 2003, J GEOPHYS RES-ATMOS, V108, ARTN 4399 ; DRUMMOND JR, 1996, J ATMOS OCEAN TECH, V13, P314 ; EISELE FL, 2003, J GEOPHYS RES-ATMOS, V108, ARTN 8791 ; EMMONS LK, 2004, J GEOPHYS RES-ATMOS, V109, ARTN D03309 ; FISHMAN J, 1990, J GEOPHYS RES-ATMOSP, V95, P3599 ; FISHMAN J, 1996, J GEOPHYS RES-ATMOS, V101, P23865 ; FUELBERG HE, 1996, J GEOPHYS RES-ATMOS, V101, P23927 ; FUELBERG HE, 1999, J GEOPHYS RES-ATMOS, V104, P5585 ; FUELBERG HE, 2000, J GEOPHYS RES-ATMOS, V105, P3633 ; HEALD CL, 2003, J GEOPHYS RES-ATMOS, V108, ARTN 4804 ; HOLLINGSWORTH A, 1986, MON WEATHER REV, V114, P861 ; JACOB DJ, 2003, J GEOPHYS RES-ATMOS, V108, ARTN 9000 ; MALONEY JC, 2001, J GEOPHYS RES-ATMOS, V106, P32609 ; NOVELLI PC, 1998, J GEOPHYS RES-ATMOS, V103, P19015 ; SACHSE GW, 1987, J GEOPHYS RES-ATMOSP, V92, P2071 ; SINGH HB, 2000, ATMOS ENVIRON, V34, P4399 ; STOHL A, 1998, ATMOS ENVIRON, V32, P947 ; VAY SA, 1998, GEOPHYS RES LETT, V25, P1717}, de = {TRACE-P; MOPITT; carbon monoxide}, di = {10.1029/2003JD004308}, doi = {10.1029/2003JD004308}, em = {james.h.crawford@nasa.govEOLEOLheald@fas.harvard.eduEOLEOLfuelberg@met.fsu.eduEOLEOLg.w.sachse@larc.nasa.govEOLEOLemmons@ucar.eduEOLEOLgille@ncar.ucar.eduEOLEOLedward@uars1.acd.ucar.eduEOLEOLmnd@ucar.eduEOLEOLg.chen@larc.nasa.govEOLEOLj.r.olson@larc.nasa.govEOLEOLvickie@stormy.larc.nasa.govEOLEOLc.kittaka@larc.nasa.govEOLEOLreh@mtu.edu}, file = {Crawford2004.pdf:Crawford2004.pdf:PDF}, ga = {827OV}, interhash = {4b19ebc96ec4464fe9d108c4fcd98c4d}, intrahash = {6a0909584e5eac69538b35c3f7421c35}, j9 = {J GEOPHYS RES-ATMOS}, ji = {J. Geophys. Res.-Atmos.}, journal = {Journal of Geophysical Research-Atmospheres}, keywords = {PACIFICEXPLORATORYMISSION;CARBON-MONOXIDE;INSTRUMENT;SATELLITE;OZONE;AIRCRAFT;PERIOD}, la = {English}, month = {#may#}, nr = {21}, number = {D15}, pa = {2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA}, pages = {D15S04}, pg = {10}, pi = {WASHINGTON}, publisher = {Amer Geophysical Union}, rp = {Crawford, JH, NASA, Langley Res Ctr, Mail Stop 483, Hampton, VA 23681EOLEOLUSA.}, sc = {Meteorology & Atmospheric Sciences}, sn = {0148-0227}, tc = {6}, timestamp = {2009-06-08T21:15:51.000+0200}, title = {Relationship between Measurements of Pollution in the Troposphere (MOPITT) and in situ observations of CO based on a large-scale feature sampled during TRACE-P}, ut = {ISI:000221911100002}, volume = 109, year = 2004 }