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

Crawford, J. H.; Heald, Colette L.; Fuelberg, Henry E.; Morse, Danielle; Sachse, G. W.; Emmons, L. K.; Gille, J. C.; Edward, D. P.; Deeter, M. N.; Chen, G.; Olson, J. R.; Connors, V. S.; Kittaka, C.; Hamlin, Amy

doi:10.1029/2003jd004308

Cited by 20 publications

(18 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The data selection follows the criteria of the MOPITT data quality statement (http://www.acd.ucar.edu/mopitt/products.shtml, access: February 2010): data within 25° from the poles have been left out, as the weight of the a priori CO profile in the MOPITT retrievals increases toward the pole. Nighttime data may be biased and are not exploited [ Crawford et al , 2004]. We then averaged the retrievals at the 3.75° × 2.5° resolution of LMDz‐SACS at the orbit level, in order to reduce the effect of correlated errors between neighboring observations in the inversion system.…”

Section: Methodsmentioning

confidence: 99%

Ten years of CO emissions as seen from Measurements of Pollution in the Troposphere (MOPITT)

et al. 2011

View full text Add to dashboard Cite

International audienceThe Measurements of Pollution in the Troposphere (MOPITT) retrievals are used as top-down constraints in an inversion for global CO emissions, for the past 10 years (from March 2000 to December 2009), at 8 day and 3.75° × 2.75° (longitude, latitude) resolution. The method updates a standard prior inventory and yields large increments in terms of annual regional budgets and seasonality. Our validation strategy consists in comparing our posterior-modeled concentrations with several sets of independent measurements: surface measurements, aircraft, and satellite. The posterior emissions, with a global 10 year average of 1430 TgCO/yr, are 37% higher than the prior ones, built from the EDGAR 3.2 and the GFEDv2 inventories (1038 TgCO/yr on average). In addition, they present some significant seasonal variations in the Northern Hemisphere that are not present in our prior nor in others' major inventories. Our results also exhibit some large interannual variability due to biomass burning emissions, climate, and socioeconomic factors; CO emissions range from 1504 TgCO (in 2007) to 1318 TgCO (in 2009)

show abstract

Section: Methodsmentioning

confidence: 99%

Ten years of CO emissions as seen from Measurements of Pollution in the Troposphere (MOPITT)

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Asian influence during TRACE‐P was weakest in the SE quadrant, which lies south of the dominant outflow track. The observed layer of high methanol concentrations at 2–4 km altitude is from one single Hawaii‐Guam flight where the aircraft sampled repeatedly an Asian outflow plume that had traveled southward and subsided [ Crawford et al , 2004]. High CO concentrations (200 ppbv) were observed in that layer.…”

Section: Evaluation With Observationsmentioning

confidence: 99%

Global budget of methanol: Constraints from atmospheric observations

et al. 2005

View full text Add to dashboard Cite

[1] We use a global three-dimensional model simulation of atmospheric methanol to examine the consistency between observed atmospheric concentrations and current understanding of sources and sinks. Global sources in the model include 128 Tg yr À1 from plant growth, 38 Tg yr À1 from atmospheric reactions of CH 3 O 2 with itself and other organic peroxy radicals, 23 Tg yr À1 from plant decay, 13 Tg yr À1 from biomass burning and biofuels, and 4 Tg yr À1 from vehicles and industry. The plant growth source is a factor of 3 higher for young than from mature leaves. The atmospheric lifetime of methanol in the model is 7 days; gas-phase oxidation by OH accounts for 63% of the global sink, dry deposition to land 26%, wet deposition 6%, uptake by the ocean 5%, and aqueous-phase oxidation in clouds less than 1%. The resulting simulation of atmospheric concentrations is generally unbiased in the Northern Hemisphere and reproduces the observed correlations of methanol with acetone, HCN, and CO in Asian outflow. Accounting for decreasing emission from leaves as they age is necessary to reproduce the observed seasonal variation of methanol concentrations at northern midlatitudes. The main model discrepancy is over the South Pacific, where simulated concentrations are a factor of 2 too low. Atmospheric production from the CH 3 O 2 self-reaction is the dominant model source in this region. A factor of 2 increase in this source (to 50-100 Tg yr À1 ) would largely correct the discrepancy and appears consistent with independent constraints on CH 3 O 2 concentrations. Our resulting best estimate of the global source of methanol is 240 Tg yr À1. More observations of methanol concentrations and fluxes are needed over tropical continents. Better knowledge is needed of CH 3 O 2 concentrations in the remote troposphere and of the underlying organic chemistry.

show abstract

“…The decrease in thermal contrast also shifts the vertical sensitivity of the MOPITT instrument upward, reducing the ability to observe low altitudes where CO concentrations are highest. Crawford et al [2004] found that nighttime observations of CO by MOPITT over the Pacific were less variable than daytime observations, which they attributed to an increase in the sensitivity of the retrieval to surface emissivity at night. We choose to use the daytime overpasses only in the results that follow.…”

Section: Constraints On Co Sources From Mopitt Observationsmentioning

confidence: 99%

Comparative inverse analysis of satellite (MOPITT) and aircraft (TRACE‐P) observations to estimate Asian sources of carbon monoxide

et al. 2004

View full text Add to dashboard Cite

[1] We use an inverse model analysis to compare the top-down constraints on Asian sources of carbon monoxide (CO) in spring 2001 from (1) daily MOPITT satellite observations of CO columns over Asia and the neighboring oceans and (2) aircraft observations of CO concentrations in Asian outflow from the TRACE-P aircraft mission over the northwest Pacific. The inversion uses the maximum a posteriori method (MAP) and the GEOS-CHEM chemical transport model (CTM) as the forward model. Detailed error characterization is presented, including spatial correlation of the model transport error. Nighttime MOPITT observations appear to be biased and are excluded from the inverse analysis. We find that MOPITT and TRACE-P observations are independently consistent in the constraints that they provide on Asian CO sources, with the exception of southeast Asia for which the MOPITT observations support a more modest decrease in emissions than suggested by the aircraft observations. Our analysis indicates that the observations do not allow us to differentiate source types (i.e., anthropogenic versus biomass burning) within a region. MOPITT provides ten pieces of information to constrain the geographical distribution of CO sources, while TRACE-P provides only four. The greater information from MOPITT reflects its ability to observe all outflow and source regions. We conducted a number of sensitivity studies for the inverse model analysis using the MOPITT data. Temporal averaging of the MOPITT data (weekly and beyond) degrades the ability to constrain regional sources. Merging source regions beyond what is appropriate after careful selection of the state vector leads to significant aggregation errors. Calculations for an ensemble of realistic assumptions lead to a range of inverse model solutions that has greater uncertainty than the a posteriori errors for the MAP solution. Our best estimate of total Asian CO sources is 361 Tg yr À1 , over half of which is attributed to east Asia.

show abstract

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

Cited by 20 publications

References 20 publications

Ten years of CO emissions as seen from Measurements of Pollution in the Troposphere (MOPITT)

Ten years of CO emissions as seen from Measurements of Pollution in the Troposphere (MOPITT)

Global budget of methanol: Constraints from atmospheric observations

Comparative inverse analysis of satellite (MOPITT) and aircraft (TRACE‐P) observations to estimate Asian sources of carbon monoxide

Contact Info

Product

Resources

About