Inverse modelling of BLACK Carbon emissions using real time data from NETworked sensors – BLACKNET

WP1 COST-EFFECTIVE BLACK CARBON SYSTEMS
Operational, cost-effective sensors, and the appropriate deployment strategy are required to expand the monitoring networks where they pre-exist, and fill geographical gaps globally. Furthermore, cost-effective sensors open the opportunity for new observing strategies, for example by allowing the implementation of denser networks at sites of interests (e.g., cities, ecologically sensitive sites), or citizen science approaches.
Nevertheless the quality, traceability and interoperability of these cost-effective sensor systems should respect clear requirements. At the moment, cheap sensors are available for some parameters of interest, but with degraded quality. WP1 aims to complete the development of cost-effective sensors systems up to TRL9 for
air quality, including a specific and original interest for BC.

WP2 INVERSE MODELLING

The objective of this work package is to improve inventories of BC in the SEA region using inverse modelling of the BC observations generated by the network of BC Pods established in scope of WP1. WP2 will also provide an evaluation of the relevance of these measurements for understanding the regional/global distribution of carbonaceous aerosol and their impact on the regional/global climate and environment.

WP3 DIRECT MODELLING

The objective is to identify the main BC source regions and transport pathways contributing to observed concentrations in a given site using regional atmospheric chemistry modelling and existing emission inventories (e.g. REAS 2.1 at 0.25°, Kurokawa et al., 2013). The model analysis will be performed during the period 2000-2016, for which we can collect a large dataset of quality assured aerosol satellite data (e.g. AERONET, MODIS, CALIOP, PARASOL, MISR) used in support to modelling. The contribution of different regions of emissions to a given receptor area will be assessed using geographically source-tagged BC tracers.
Combined with satellite observations of pollution transport, this information will be used to connect receptor regions to source regions as a first guess before quantitative inverse modelling developed in WP2. This analysis will benefit to the qualification of the observational sites regarding their ability to measure large scale versus local contributions to BC load. Given the range of processes, spatial and temporal scales involved, regional model of different complexities will be used.

Automatic black carbon analysers have been developed and compared with commercial instruments. Deployment has begun in Vietnam and Thailand.
Inverse modelling has been set up and tests have been carried out.

The BC measurements carried out in Bangkok and Chiangmai in the north of Thailand have enabled us to characterise very different combustion sources, characterised by fossil fuels in Bangkok and biomass fires in Chiangmai.
characterise very different combustion sources, marked by fossil fuels in Bangkok and biomass fires in Chiangmai.
With the support of various funding sources, the IRD is pursuing its objective of obtaining funding for a black carbon observatory in South Asia. BLACKNET is part of this ambitious approach.

Scientific articles
In preparation

Communications
Participation in the regional workshop on Environmental Systems in South East Asia, Hanoi Dec 2023
Participation in the American Geophysical Union Conference Dec 2023

Black carbon (BC) contributes to global warming by absorbing sunlight. Current global climate models systematically underpredict the atmospheric aerosol absorption by a factor of three when compared to observations, which is often attributed to the underestimation of BC emissions [Bond et al. 2004, 2013; Textor et al. 2006]. Emission inventories of BC are traditionally constructed using a bottom-up approach based on activity data and emissions factors (EF). EF determination requires highly expensive (both in time and means) meticulous methodologies, which leads in practice to emission data with very heterogeneous quality in space and time [Lamarque et al. 2010; Granier et al. 2011]. Southeast Asia (SEA) hosts a multiplicity of combustion sources emitting large amounts of BC in the atmosphere: biomass burning including peatland and forest fires and domestic usage of biofuels, oil products for transportation, but it will be particularly affected by coal burning to meet the explosive energy demand over the next decades. This part of Asia also stands downstream the intense BC emissions from China in winter. As a result, all the trends quantitatively go upwards and point SEA as the top priority region of the world to be investigated. International programs have attempted to simulate the effects of BC on climate in SEA, all pointed out that better time and space resolved emissions inventories are the crucial point to improve forecast and climate models [Koch et al. 2009; Bond et al. 2013]. BLACKNET will lead to a new cost-effective operational system to monitor BC along with other combustion tracers, and subsequently identify, localise and characterise their sources.
(1) The first objective is technical: the development and operational demonstration of a network of BC sensors deployed over the Indochinese Peninsula, providing continuously collected & computed data. (2) The second objective is scientific: the consecutive development of innovative atmospheric data products relying on inverse modelling based on communicating BC sensors, in order to improve and validate top-down BC emissions inventories. The consortium includes internationally recognized researchers and research groups in the fields of aerosol characterization, inverse modelling, emission inventories and regional/global modelling. The field work achievements are ensured by the strong involvement in the project of the Asian Institute of Technology in Bangkok and the Vietnamese Academy of Science and Technology, in the frame of an International Research Group (GDRI-Sud) dedicated to BC impacts in Southeast Asia, and funded over the period 2018-2021 by IRD and the leading laboratories, including LA – the coordinator of the present BLACKNET proposal. Impacts are expected on potential market development as new opportunities will emerge for the French Earth observation commercial sector, mainly technology/sensor and data treatment software providers and for downstream users - service providers - with the definition and demonstration of new services and the enablement of new science applications. The project outputs will fit into international frameworks like the Global Emissions InitiAtive (GEIA), the Copernicus Atmosphere Monitoring Service, particularly CAMS-43 about aerosols, from which data will be used for comparison, and the ASEAN Agreement on Transboundary Haze Pollution which binds the ten ASEAN Member Countries to tackle transboundary haze pollution.