TCCON Philippines: First Measurement Results, Satellite Data and Model Comparisons in Southeast Asia

Creators: Velazco, Voltaire A.; Morino, Isamu; Uchino, Osamu; Hori, Akihiro; Kiel, Matthäus; Bukosa, Beata; Deutscher, Nicholas M.; Sakai, Tetsu; Nagai, Tomohiro; Bagtasa, Gerry; Izumi, Toshiharu; Yoshida, Yukio; Griffith, David W. T.

Abstract

The Total Carbon Column Observing Network (TCCON) is a global network dedicated to the precise and accurate measurements of greenhouse gases (GHG) in the atmosphere. The TCCON station in Burgos, Ilocos Norte, Philippines was established with the primary purpose of validating the upcoming Greenhouse gases Observing SATellite-2 (GOSAT-2) mission and in general, to respond to the need for reliable ground-based validation data for satellite GHG observations in the region. Here, we present the first 4 months of data from the new TCCON site in Burgos, initial comparisons with satellite measurements of CO_2 and model simulations of CO . A nearest sounding from Japan's GOSAT as well as target mode observations from NASA's Orbiting Carbon Observatory 2 (OCO-2) showed very good consistency in the retrieved column-averaged dry air mole fractions of CO_2 , yielding TCCON - satellite differences of 0.86 ± 1.06 ppm for GOSAT and 0.83 ± 1.22 ppm for OCO-2. We also show measurements of enhanced CO , probably from East Asia. GEOS-Chem model simulations were used to study the observed CO variability. However, despite the model capturing the pattern of the CO variability, there is an obvious underestimation in the CO magnitude in the model. We conclude that more measurements and modeling are necessary to adequately sample the variability over different seasons and to determine the suitability of current inventories.

Additional Information

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Received: 8 September 2017; Accepted: 22 November 2017; Published: 28 November 2017. (This article belongs to the Special Issue Remote Sensing of Greenhouse Gases) The TCCON Philippines project is supported in part by the GOSAT-2 project of Japan. Retrieval processing for GOSAT SWIR L2 was conducted at the Research Computation Facility for GOSAT-2. We also thank the Japanese Ministry of Environment. We acknowledge the tremendous support from EDC, especially from F. R. Lopez, O. M. Lopez, R. B. Tantoco, A. de Jesus, EDC board members, J. Russell, OML Center for Climate Change and First Philippine Holdings. Special thanks to Art Valdez. Site support is also generously provided by R. Chua, A. Durog, C. Aguilar and all EBWPC staff. We also thank the government of Ilocos Norte. The authors also thank NIES for providing GOSAT data via the GOSAT RA projects (V. Velazco [RA8]). We thank NASA for providing the OCO-2 retrospective data, available from GES-DISC. We thank F. Schwandner, G. Ostermann, A. Eldering, D. Crisp and the rest of the OCO-2 team for facilitating the target mode observations. We thank PAGASA-DOST for the Met-Hydro Decision Support Infosys website for daily weather information. We acknowledge support from TCCON partners especially Debra Wunch, Geoffrey C. Toon, Paul O. Wennberg. Funding is provided in part by the Australian Research Council (ARC) for TCCON (DP160101598, DP140101552, DP110103118) and University of Wollongong SMAH-UIC International Links Grant Scheme for travel support granted to Velazco. This research was undertaken with the assistance of resources from the NCI National Facility systems at the Australian National University through the National Computational Merit Allocation Scheme supported by the Australian Government. B. Bukosa would like to acknowledge support from both the ARC and the University of Wollongong. N. Deutscher acknowledges support from ARC-DECRA (DE140100178). We thank Jenny A. Fisher for valuable discussions and help with GEOS-Chem and the tagged tracer studies. We thank the three anonymous referees for providing valuable reviews that helped improve this manuscript. Author Contributions: V.A.V. conceived the manuscript, processed and analyzed TCCON data, calculated the satellite coincidences (GOSAT), determined the GEOS-Chem offset and was involved in instrument set-up and Burgos operations. I.M. is the TCCON instrument PI and led the set-up of the NIES FTS container system, is involved in day-to-day operations and pre-processing of level 0 data and data analysis. A.H. is the dedicated instrument engineer responsible for instrument set-up, day-to-day operations and pre-processing of level 0 data. O.U. is the LiDAR PI and leads the LiDAR set-up, operations and wrote the LiDAR results and analysis sections. T.S., T.I., T.N. are all involved in LiDAR instrument set-up and data analysis. G.B. contributed to the LiDAR operations and provided weather data. Y.Y. processed and provided advanced Level 2 GOSAT data. M.K. did the OCO-2 data processing, bias correction and TCCON comparisons, wrote the OCO-2 section. B.B. did the modeling (CO and CH4, CO2), contributed to the analysis and wrote the GEOS-Chem chapter. N.D. contributed to the GEOS Chem tagged tracers analysis and provided valuable inputs. D.G. guided the TCCON instrument set-up, helped with measurements, set the preprocessing routines up and contributed to the data analysis. All authors read and provided comments on the manuscript. The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Attached Files

Published - remotesensing-09-01228.pdf

Files

remotesensing-09-01228.pdf

Files (5.3 MB)

Name	Size	Download all
remotesensing-09-01228.pdf md5:4f0151cf2c0ab03e9821a6b813155edd	5.3 MB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes