Research Focus Research Interests Projects CV - Past Work Presentations Publications

Julia Marshall Research Scientist Leader of Satellite-based Remote Sensing of Greenhouse Gases Group Phone: + 49 3641 576383 fax: + 49 3641 577300 email: marshall@bgc-jena.mpg.de

Research Focus:

• Understanding fluxes of carbon dioxide and methane using satellite measurements
• Harmonizing flux estimates based on satellite- and surface-based measurements
• Supporting the development of new satellite missions

Research Interests:

I am working with satellite measurements of greenhouse gases to better understand the carbon cycle. For this purpose I use a technique known as inverse, or top-down modelling, whereby atmospheric measurements of trace gas concentrations are used together with an atmospheric transport model to constrain our knowledge of surface fluxes. Using the relatively new column-integrated satellite measurements in this context brings with it a host of challenges and opportunities, as the measurements simultaneously provide greatly improved data coverage coupled with difficult to characterize systematic errors.

Current Projects:

• GHG-CCI Phase 2: The greenhouse gas component of ESA's Climate Change Initiative. The goal of the project is to develop high-quality consistent retrievals of column-integrated measurements of carbon dioxide and methane (XCO₂ and XCH₄ respectively). To that end I am part of the Climate Research Group, which provides user-based feedback by assimilating the data products from the different retrieval teams into various retrieval systems.
• CLEARSKY: An optional work package within GHG-CCI, also funded by ESA, to examine the affect of a clear-sky bias in XCO₂ measurements on retrieved fluxes.
• GAIA-CLIM: This H2020-funded project focusses on Gap Analysis for Integrated Atmospheric ECV (Essential Climate Variable) CLImate Monitoring. In it I am assessing the representativeness of the current ground-based network of Fourier Transform Spectrometers, TCCON (Total Carbon Column Observing Network), for the validation of space-based total column measurements. For this study I am assessing their representativeness not only in concentration space but also in geophysical parameter space, using the parameters (albedo, pressure gradients, etc.) that are currently employed in empirical bias correction schemes.
• CoMet: The Carbon dioxide and Methane mission on board HALO, the high altitude aircraft of the German Space Agency (DLR) will take place in May, 2017. In addition to targeting interesting emission sources in Europe, one of its goals is to compare the measurements from the active CO₂/CH₄ differential-absorption-based sensor CHARM-F with high-precision in situ measurements. This will provide feedback for the development of the satellite sensor for MERLIN, described below. I am contributing through mesoscale modelling using WRF-GHG for both forecasts for flight planning and hindcasts together with the Lagrangian model STILT for inverse modelling.
• MERLIN: A joint mission between the German and French Space Agencies (DLR and CNES), MERLIN aims to be the first active lidar mission to measure methane from space. Its launch is currently planned for 2021. I am a member of the Scientific Advisory Group, and contribute to preparatory studies.

Previous Projects:

• IGAS: I managed this project, which ran from 2013-2016, and focussed on better integrating the measurements performed by IAGOS on board commercial airliners into the Copernicus Atmosphere Monitoring Service (CAMS). Research included the use of routine aircraft measurements for validation of satellite measurements. The project was funded by the European Commission through FP7.

CV - Past work:

My previous scientific work pertained to aerosols and their optical properties, from the perspective of both measurement and modelling.

• Curriculum Vitae

Publications:

See list here.