Chemistry and transport of pollution over the Gulf of Mexico and the Pacific: Spring 2006 INTEX-B Campaign overview and first results

Abstract

Abstract. Intercontinental Chemical Transport Experiment-B (INTEX-B) was a major NASA1 led multi-partner atmospheric field campaign completed in the spring of 2006 (http://cloud1.arc.nasa.gov/intex-b/). Its major objectives aimed at (i) investigating the extent and persistence of the outflow of pollution from Mexico; (ii) understanding transport and evolution of Asian pollution and implications for air quality and climate across western North America; and (iii) validating space-borne observations of tropospheric composition. INTEX-B was performed in two phases. In its first phase (1–21 March), INTEX-B operated as part of the MILAGRO campaign with a focus on observations over Mexico and the Gulf of Mexico. In the second phase (17 April–15 May), the main INTEX-B focus was on the trans-Pacific Asian pollution transport. Multiple airborne platforms carrying state of the art chemistry and radiation payloads were flown in concert with satellites and ground stations during the two phases of INTEX-B. Validation of Aura satellite instruments (TES, OMI, MLS, HIRDLS) was a key objective within INTEX-B. Satellite products along with meteorological and 3-D chemical transport model forecasts were integrated into the flight planning process to allow targeted sampling of air parcels. Inter-comparisons were performed among and between aircraft payloads to quantify the accuracy of data and to create a unified data set. Pollution plumes were sampled over the Gulf of Mexico and the Pacific several days after downwind transport from source regions. Signatures of Asian pollution were routinely detected by INTEX-B aircraft, providing a comprehensive data set on gas and aerosol composition to test models and evaluate pathways of pollution transport and their impact on air quality and climate. This overview provides details about campaign implementation and a context within which the present and future INTEX-B/MILAGRO publications can be understood. 1 Acronyms are provided in Appendix A.

Extending the Community Multiscale Air Quality (CMAQ) modeling system to hemispheric scales: overview of process considerations and initial applications

“…Thus, O 3 in air masses entering western North America is comprised of both anthropogenic contributions due to long-range transport of aged pollution from Asia and central America and a natural stratospheric component. The composite O 3 vertical profile during this period derived from the hemispheric CMAQ is within the range of those predicted by other global atmospheric chemistry models illustrated in Singh et al (2009).…”

“…In this section we present an overview of these diverse evolving applications with the hemispheric CMAQ model. In some instances, the applications have been detailed before, but the analysis summarized here builds upon that pre- (Table 5a in Singh et al, 2009). Modeled mixing ratios were extracted by flying the aircraft through the 3-D modeling domain; the spatial locations of the aircraft were mapped to the model grid, whereas hourly model output was temporally interpolated to the time of the measurement.…”

Impact of agricultural waste burning in the Shandong Peninsula on carbonaceous aerosols in the Bohai Rim, China

“…It is located in northern China around the Bohai Sea and comprises Beijing and Tianjin municipalities as well as part of Hebei, Liaoning and Shandong provinces. Both international field campaigns and sampling campaigns carried out on remote islands showed that carbonaceous aerosols emitted from the Bohai Rim region could be detected in the downstream areas and coal burning was the main source of the continental outflow (Feng et al, 2007(Feng et al, , 2012Lim et al, 2003;Ma et al, 2012;Singh et al, 2009). However, extensive inventory studies showed that agricultural waste burning was a main emission source of carbonaceous aerosols in the region and open burning of crop residues in Shandong was the largest contributor of carbonaceous aerosols in the sector in China (Cao et al, 2006;Xie, 2011, 2012).…”

Impact of mineral dust on nitrate, sulfate, and ozone in transpacific Asian pollution plumes

“…We consider flights of the NASA DC8 out of Honolulu, Hawaii, and Anchorage, Alaska (Regions 3 and 4 in Fig. 2a of Singh et al, 2009). We focus particularly on explaining observed particulate nitrate levels, ramifications for the lifetime of HNO 3 (g) with respect to uptake on dust, and whether dust can account for the high bias of HNO 3 (g) in models.…”

“…In this paper, we use a 3-D global chemical transport model (GEOS-Chem CTM) to investigate the effect of mineral dust on the chemical partitioning of total inorganic nitrate and sulfate over the Northeast Pacific during the spring 2006 INTEX-B airborne campaign (Singh et al, 2009). This campaign focused on intercontinental transport of pollution from Asia to North America.…”