Intermediate-scale horizontal isoprene concentrations in the near-canopy forest atmosphere and implications for emission heterogeneity

Journal Article · Mon Sep 09 00:00:00 EDT 2019 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.1904154116· OSTI ID:1581366

Batista, Carla E. ^[1]; Ye, Jianhuai ^[2]; Ribeiro, Igor O. ^[1]; Guimarães, Patricia C. ^[1]; Medeiros, Adan S. S. ^[1]; Barbosa, Rafael G. ^[3]; Oliveira, Rafael L. ^[3]; Duvoisin, Sergio ^[1]; Jardine, Kolby J. ^[4]; Gu, Dasa  ^[5]; Guenther, Alex B. ^[6]; McKinney, Karena A. ^[7]; Martins, Leila D. ^[8]; Souza, Rodrigo A. F. ^[1]; Martin, Scot T.  ^[2]

---

1. National Inst. of Amazonian Research, Amazonas (Brazil); Amazonas State Univ. (Brazil)
2. Harvard Univ., Cambridge, MA (United States)
3. Amazonas State Univ. (Brazil)
4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
5. Univ. of California, Irvine, CA (United States); Hong Kong Univ. of Science and Technology (China)
6. Univ. of California, Irvine, CA (United States)
7. Colby College, Waterville, ME (United States)
8. Federal Univ. of Technology, Paraná (Brazil)

The emissions, deposition, and chemistry of volatile organic compounds (VOCs) are thought to be influenced by underlying landscape heterogeneity at intermediate horizontal scales of several hundred meters across different forest subtypes within a tropical forest. Quantitative observations and scientific understanding at these scales, however, remain lacking, in large part due to a historical absence of canopy access and suitable observational approaches. Herein, horizontal heterogeneity in VOC concentrations in the near-canopy atmosphere was examined by sampling from an unmanned aerial vehicle (UAV) flown horizontally several hundred meters over the plateau and slope forests in central Amazonia during the morning and early afternoon periods of the wet season of 2018. Unlike terpene concentrations, the isoprene concentrations in the near-canopy atmosphere over the plateau forest were 60% greater than those over the slope forest. A gradient transport model constrained by the data suggests that isoprene emissions differed by 220 to 330% from these forest subtypes, which is in contrast to a 0% difference implemented in most present-day biosphere emissions models (i.e., homogeneous emissions). Finally, quantifying VOC concentrations, emissions, and other processes at intermediate horizontal scales is essential for understanding the ecological and Earth system roles of VOCs and representing them in climate and air quality models.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); Brazilian Federal Agency for Support and Evaluation of Graduate Education; Brazilian National Council for Scientific and Technological Development; Amazonas State Research Foundation; National Science Foundation (NSF)
• Grant/Contract Number: AC02-05CH11231; 88881.187481/2018-01; 062.00568/2014; 062.00491/2016; AGS-1829025; AGS-1829074
• OSTI ID: 1581366
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Vol. 116, Issue 39; ISSN 0027-8424
• Publisher: National Academy of Sciences
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
isoprene emissions
landscape heterogeneity
intermediate horizontal scales
Amazon tropical
forest
UAV measurements