Preface to Special Section on Biomass Burning and Lightning Experiment (BIBLE)

Transcription

1 JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. D3, 8397, doi: /2002jd002401, 2003 Preface to Special Section on Biomass Burning and Lightning Experiment (BIBLE) Y. Kondo, 1 M. Ko, 2 M. Koike, 3 S. Kawakami, 4 and T. Ogawa 4 Received 31 March 2002; revised 3 May 2002; accepted 28 May 2002; published 22 November INDEX TERMS: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0345 Atmospheric Composition and Structure: Pollution urban and regional (0305); 0365 Atmospheric Composition and Structure: Troposphere composition and chemistry; 0368 Atmospheric Composition and Structure: Troposphere constituent transport and chemistry; KEYWORDS: BIBLE, biomass burning, lightning, aerosol, ozone tropical western Pacific Citation: Kondo Y., M. Ko, M. Koike, S. Kawakami, and T. Ogawa, Preface to Special Section on Biomass Burning and Lightning Experiment (BIBLE), J. Geophys. Res., 107, 8397, doi: /2002jd002401, [printed 108(D3), 2003] 1. Introduction [1] In tropical Asia, and in the Indonesian maritime continent and northern Australia in particular, trace gas and aerosol distributions in the troposphere are strongly influenced by deep convection, frequent lightning, and biomass burning. Quantitative studies of these processes in this region have been very limited because of the lack of simultaneous measurements of key trace species. To study important natural and anthropogenic processes in tropical Asia and the Pacific, the Biomass Burning and Lightning Experiment (BIBLE) was conducted by the Earth Observation Research Center (EORC) of the National Space Development Agency of Japan (NASDA) between 1998 and 2000, in close collaboration with the International Global Atmospheric Chemistry (IGAC) program. The BIBLE activity was comprised of in situ observations aboard Gulfstream II (G-II) aircraft supplemented with simultaneous satellite observations and numerical modeling efforts. [2] Concentrations of ozone precursors in the tropical maritime troposphere are usually quite low, and as a result, the net production of ozone is negative. However, biomass burning is an important source of ozone precursors and aerosols during the dry season in the tropical troposphere. There is evidence for positive net ozone production in the biomass burning plumes from Indonesia and tropical Australia. In the late dry season (September October) during El Niño periods, as in 1994 and 1997, large-scale biomass burning occurred in Indonesia leading to significant increases in ozone [Fujiwara et al., 1999; Kita et al., 2000]. Biomass burning has been reported to occur regularly in northern 1 Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan. 2 Atmospheric and Environmental Research, Inc., Lexington, Massachusetts, USA. 3 Department of Earth and Planetary Sciences, University of Tokyo, Tokyo, Japan. 4 Earth Observation Research Center, National Space Development Agency of Japan, Tokyo, Japan. Copyright 2002 by the American Geophysical Union /02/2002JD Australia in the dry season. In the rainy season, lightning is an important source of reactive nitrogen in the tropical region as predicted by models [e.g., Levy et al., 1999]. We conducted a test flight campaign (BIBLE T) and two major deployments (BIBLE A and B) as listed in Table 1. Some of the results obtained during BIBLE Tare given by Miyazaki et al. [2002]. Major scientific issues involving biomass burning studied by BIBLE A and B were (1) estimate the amounts of trace gases and aerosols emitted by biomass burning and lightning, (2) Study vertical transport of air impacted by biomass burning, (3) Study the long-range transport and chemical transformation of trace species in the biomass burning plumes, and (4) Evaluate the impact of emitted ozone precursors on ozone photochemistry. [3] BIBLE A (B) was conducted between 24 September and 10 October 1998 (30 August and 14 September 1999) after test flights from Nagoya, as summarized in Tables 2a and 2b. The flight tracks and altitude profiles during BIBLE A and B are shown in Figures 1, 2a, and 2b. During BIBLE A, the G-II flew from Nagoya (35.3 N, E) to Bandung (6.9 S, E), Indonesia via Saipan (15 N, 146 E), Biak (1.2 S, E), and Darwin (12.4 S, E). The return route was Bandung-Biak-Saipan-Nagoya. Coordinated balloon-borne ozonesonde measurements were carried out at Watukosek (7.5 S, E) on Java Island, Kototabang (0.2 S, E) on Sumatra Island, and Pontianak (0.03 N, E) on Borneo Island in Indonesia. Nineteen ozonesonde measurements in total were made from these three stations between 23 September and 9 October [4] During BIBLE B, the G-II flew from Nagoya to Darwin via Saipan, and Port Moresby (9.4 S, E). The return route was Darwin-Biak-Saipan-Nagoya. Coordinated balloon-borne ozonesonde measurements were carried out in Darwin, Watukosek, and Kototabang between 25 August and 13 September [5] Instruments used for BIBLE A and B aircraft measurements are listed in Table 3, together with the responsible principal investigators and measurement characteristics. In addition to the concentration measured by the instruments on the G-II, a photochemical box model was used to calculate quantities along the flight track [Ko et al., BIB 1-1

2 BIB 1-2 KONDO ET AL.: PREFACE Table 1. Periods and Locations of the BIBLE Campaigns BIBLE Phase Period Major Base T April 1998 Nagoya, Japan A dry season: 24 September to Bandung, Indonesia 10 October 1998 B dry season: 30 August to 14 September 1999 Darwin, Australia 2002]. The results from the box model were then used in a diurnal model to estimate the diurnally averaged production and removal rates for ozone at the sampling point. 2. Findings From BIBLE A and B [6] Through the use of air-trajectory analyses [e.g., Kondo et al., 2002; Koike et al., 2002; Kita et al., 2002]; analyses of auxiliary satellite data to identify convective activities (GMS-5 infra-red cloud image data), biomass burning activities (ATSR World Fire Atlas), and lightning activities (OTD on Microlab Satellite and LIS on TRMM); studies of correlations of various measured species concentrations; and specific correlation analysis of hydrocarbon measurements [Elliott et al., 2002], the measured concentrations were interpreted in terms of the origin of the air masses and the processes that affect them. [7] Air over the tropical Pacific region is distinguished from the rest of the region by smaller concentrations of O 3, CO, NO y, NO, and NMHCs. This can be explained in terms of the absence of surface sources over the ocean, lack of stratospheric intrusion, and the preclusion of midlatitude air and air from the west due to active convection throughout the troposphere [Kondo et al., 2002]. As a result, the measurements from BIBLE A and BIBLE B did not provide much information regarding air mass exchange between the Asian mainland and western Pacific. However, analyses of the NMHC data from BIBLE T over the western midlatitude Pacific provided useful information [Miyazaki et al., 2002]. [8] During BIBLE A, biomass burning activities over Indonesia region were weak, due partly to La Niña condition. Mixing ratios of NO x and NO y in air masses that had crossed over Indonesia within three days prior to the measurement were systematically higher than those in air masses originating from the central Pacific. In-situ production by lightning was suggested as a significant source of NO x (increases of pptv corresponding to 80% of the observed level in the upper troposphere), although convective transport of air masses influenced by surface sources also increased the NO y level [Koike et al., 2002]. [9] In addition to NO x and NO y, mixing ratios of other ozone precursor gases were also higher than the marine background values in the upper troposphere above 8 km over Indonesia. Kita et al. [2002] estimated contributions from fossil fuel combustion and biomass burning as sources of ozone precursors. NMHC correlations revealed that the Indonesian atmosphere was rich in biomass burning markers and also those of vehicular activity. The complexity of air chemistry in the archipelago is a direct reflection of diverse topography, land use and local economies in a rapidly developing nation [Elliott et al., 2002]. Trajectory analysis indicates that ozone mixing ratio increased at an average rate of 1.8 ppbv/day in the air masses transported from Indonesia to northern Australia. This is consistent with estimates from the photochemical model [Ko et al., 2002]. [10] Over Australia, air in the boundary layer and air in the upper troposphere have distinct origins. Due to stable high pressure over northern Australia, downward motions were predominant both in the upper and lower troposphere for the duration of BIBLE B. The well-defined inversion layers and strong downward motions prevented the biomass burning emissions from going up to the free troposphere during BIBLE B. [11] Estimates of the extent of savanna burning (from calibrated coarse-resolution Advanced Very High Resolution Radiometer (AVHRR) data available twice daily) and associated consumption of fine (<6 mm diameter) grass and litter fuels (derived from published fuel accumulation relationships) were made for an extensive 230,000 km 2 continental region near Darwin during BIBLE B [Russell-Smith et al., 2002]. Over the 25-day study period, it is estimated that 43,000 km 2 were burnt, consuming Mt (10 9 gm) DM (dry mass) of fine fuels. Emission ratios and emission factors were determined for 20 NMHCs, 3 methyl halides, DMS, and CH 4 based on the measured concentrations in the boundary layer and the enhancements over the background concentrations. The emission factors varied with burning conditions, such as combustion efficiency. In addition, emission factors of CO, CH 4 and NMHCs varied signifi- Table 2a. Dates and Locations of the BIBLE A Flights at Nagoya (36 N), Saipan (15 N), Biak (1 S), Balikpapan (1 S), Bandung (7 S), and Darwin (12 S) Flight Number Description Date 1998 Day Number Take Off UT Landing UT 1 Test flight (Nagoya) Sept :28 04:53 2 Transit: Nagoya-Saipan Sept :18 05:50 3 Transit: Saipan-Biak Sept :10 02:38 4 Transit: Biak-Darwin Sept :05 08:12 5 Darwin local Sept :37 06:17 6 Transit: Darwin-Bandung Sept :45 04:45 7 Bandung local (over Kalimantan Is.) Sept :26 08:21 8 Bandung local (over Sumatra Is.) Sept :18 07:15 9 Bandung local (between Jawa & Kalimantan Is.) Oct :32 07:42 10 Bandung local (S of Jawa Is.) Oct :09 06:56 11 Bandung local (W of Sumatra Is.) Oct :00 07:09 12 Transit: Bandung-Balikpapan Oct :01 04:01 13 Transit: Balikpapan-Biak Oct :03 08:04 14 Transit: Biak-Saipan Oct :18 08:44 15 Transit: Saipan-Nagoya Oct :14 03:51

3 KONDO ET AL.: PREFACE BIB 1-3 Table 2b. Dates and Locations of the BIBLE B Flights at Nagoya (36 N), Saipan (15 N), Biak (1 S), Port Moresby (9 S), and Darwin (12 S) Flight Number Description Date 1999 Day Number Take Off UT Landing UT 1 Test flight (Nagoya) Aug :58 07:28 2 Transit: Nagoya Saipan Aug :26 05:57 3 Transit: Saipan Port Moresby Aug :04 02:39 4 Transit: Port Moresby Darwin Aug :59 07:32 5 Darwin local (Darwin Cairns) Sept :59 03:42 6 Darwin local (Cairns Darin) Sept :58 08:22 7 Darwin local (over Arhnemland) Sept :13 07:49 8 Darwin local (over Timor Sea) Sept :56 03:19 9 Darwin local (Darwin Alice Springs) Sept :54 03:38 10 Darwin local (Alice springs Darwin) Sept :41 07:59 11 Transit: Darwin Biak Sept :29 02:12 12 Transit: Biak Saipan Sept :20 06:39 13 Transit: Saipan Nagoya Sept :52 03:25 cantly among different vegetation types, while those of CO 2 varied little. The estimated annual trace gas emissions from Australian savanna fires significantly reduce the uncertainty in Australian biomass burning estimates [Shirai et al., 2002]. [12] Analyses based on 14-day back trajectories identified free-tropospheric air over Australia that originated from Indonesia, the Indian Ocean, Africa, and southern midlatitudes. The levels of O 3 and its precursors in these air masses were much higher than those from the tropical Pacific due to their larger sources from biomass burning and lightning. Effects of biomass burning and lightning are discussed as possible sources of O 3 and its precursors in these air masses [Kondo et al., 2002]. [13] In cloud-free air (RH < 90%) over the tropical Pacific, the total aerosol volume (density) was low and approximately constant above 5 km. The concentration of condensation nuclei (CN) increased from a minimum at about 4 km altitude to a maximum around 10 km, where the mixing ratio was often greater than in the boundary layer. This suggests significant production of new particles in the upper tropical troposphere [Liley et al., 2002]. [14] On the BIBLE B flights over Australia, very high concentrations of black carbon were measured and they Figure 1. Flight tracks for the G-II aircraft during (a) BIBLE A and (b) BIBLE B campaigns.

4 BIB 1-4 KONDO ET AL.: PREFACE Figure 2a. Detailed flight tracks for BIBLE A.

5 KONDO ET AL.: PREFACE BIB 1-5 Figure 2a. (continued) strongly correlated with estimates from the MASP data of total particle mass and with CO 2, CO, NO x, CH 4, and NMHC measurements. The black carbon represents as much as one quarter of the dry aerosol mass. The correlations with gas species show that black carbon represented 0.5% of total airborne carbon, which was dominated by CO 2 (92%) and CO (7%), exceeding the CH 4 fraction and the combined total of all other NMHCs [Liley et al., 2002].

6 BIB 1-6 KONDO ET AL.: PREFACE Figure 2a. (continued)

7 KONDO ET AL.: PREFACE BIB 1-7 Figure 2a. (continued) Table 3. Instruments Used Aboard the G-II Aircraft During BIBLE A and B a Species/Parameter Investigator Code BIBLE A or B Technique Averaging Time Accuracy Precision LOD, pptv NO A A/B chemiluminescence 1 s 8% 6 pptv 13 pptv NO y A A/B chemiluminescence 1 s 17% 16 pptv 28 pptv O 3 B A/B UV absorption 1 s 5% 0.6 ppbv hpa CO C B resonance fluorescence 1 s 5% 1.4 ppbv 2.2 ppbv CO B A/B GC/HgO reduction 20 s 5% 2 ppbv 4 ppbv CO 2 D A/B IR absorption 1 s 0.3 ppmv 0.1 ppmv H 2 O E A/B cryogenic chilled mirror hygrometer 60 s C C 100 C to+20 C H 2 O E A/B thermoelectric hygrometer 60 s C C 75 C to +50 C NMHCs (C 2 C 10 ) F A/B grab sample/gc 60 s 5 10% 1 3% 3 pptv Halocarbons (C 1 C 2 ) F A/B grab sample/gc 60 s 2 20% 1 10% pptv Alkylnitrates (C 1 C 4 ) F A/B grab sample/gc 60 s 10 20% 1 10% 0.02 pptv Aerosol size distribution G A/B MASP 1 s 30% <1% 0.1 cm 3 CN G A/B CN counter 1 s 5 p N 0.04 cm cm 3 Black carbon G B aethalometer 10 s 40% 0.1 mg m mg m 3 J (NO 2 ) B A/B filter radiometer 1 s 8% 1.5( 4) s 1 3.0( 4) s 1 J(O 1 D) B A/B filter radiometer 1 s 15% 0.8( 6) s 1 2.5( 6) s 1 a LOD is limit of detection. Investigator code: A, Y. Kondo/M. Koike; B, K. Kita; C, Y. Kondo/N. Takegawa; D, T. Machida/G. Inoue; E, S. Kawakami/ Y. Kondo; F, D. Blake/T. Shirai; G, B. Liley/D. Baumgardner.

8 BIB 1-8 KONDO ET AL.: PREFACE Figure 2b. Same as Figure 2a but for BIBLE B.

9 KONDO ET AL.: PREFACE BIB 1-9 Figure 2b. (continued)

10 BIB 1-10 KONDO ET AL.: PREFACE Figure 2b. (continued)

11 KONDO ET AL.: PREFACE BIB 1-11 [15] Finally, the measured latitudinal distributions of CO 2 were used to derive information on sources and sinks of CO 2, and the effects of interhemispheric transport [Machida et al., 2002]. References Elliott, S., D. R. Blake, N. J. Blake, M. K. Dubey, F. S. Rowland, B. C. Sive, and F. A. Smith, BIBLE A whole-air sampling as a window on Asian biogeochemistry, J. Geophys. Res., 107, doi: /2001jd000790, in press, Fujiwara, M., K. Kita, S. Kawakami, T. Ogawa, N. Komala, S. Saraspriya, and A. Suripto, Tropospheric ozone enhancements during the Indonesian forest fire events in 1994 and in 1997 as revealed by ground-based observations, Geophys. Res. Lett., 26, , Kita, K., M. Fujiwara, and S. Kawakami, Total ozone increase associated with extensive forest fires over the Indonesian region and its relation with El Niño-Southern Oscillation, Atmos. Environ., 34, , Kita, K., et al., Photochemical production of ozone in the upper troposphere in association with cumulus convection over Indonesia, J. Geophys. Res., 107, doi: /2001jd000844, in press, Ko, M., W. Hu, J. Rodriguez, Y. Kondo, M. Koike, K. Kita, S. Kawakami, D. Blake, S. Liu, and T. Ogawa, Photochemical ozone budget during the BIBLE A and B campaigns, J. Geophys. Res., 107, doi: / 2001JD000800, in press, Koike, M., et al., Reactive nitrogen over the tropical western Pacific: Influence from lightning and biomass burning during BIBLE A, J. Geophys. Res., 107, doi: /2001jd000823, in press, Kondo, Y., et al., Effects of biomass burning, lightning, and convection on O 3, CO, and NO y over the tropical Pacific and Australia in August October 1998 and 1999, J. Geophys. Res., 107, doi: /2001jd000820, in press, Levy, H., II, W. J. Moxim, K. A. Klonecki, and P. S. Kashibhatla, Simulated tropospheric NO x : Its evaluation, global distribution and individual source contributions, J. Geophys. Res., 104, 26,279 26,306, Liley, J. B., et al., Black carbon in aerosol during BIBLE B, J. Geophys. Res., 107, doi: /2001jd000845, in press, Machida, T., K. Kita, Y. Kondo, D. Blake, S. Kawakami, G. Inoue, and T. Ogawa, Vertical and meridional distributions of the atmospheric CO 2 mixing ratio between northern midlatitudes and southern subtropics, J. Geophys. Res., 107, doi: /2001jd000910, in press, Miyazaki, Y., K. Kita, Y. Kondo, M. Koike, M. Ko, W. Hu, S. Kawakami, D. R. Blake, and T. Ogawa, Springtime photochemical ozone production observed in the upper troposphere over East Asia, J. Geophys. Res., 107, doi: /2001jd000811, in press, Russell-Smith, J., A. C. Edwards, and G. D. Cook, Reliability of biomass burning estimates from savanna fires: Biomass burning in northern Australia during the 1999 Biomass Burning and Lightning Experiment B field campaign, J. Geophys. Res., 107, doi: /2001jd000787, in press, Shirai, T., et al., Emission estimates of selected volatile organic compounds from tropical savanna burning in northern Australia, J. Geophys. Res., 107, doi: /2001jd000841, in press, 2002.