May 122017

Following the past symposia in Lille, France in 2007 and in New Orleans in 2010, the 3rd NASA A-Train symposium was held on 19-21 April in Pasadena (California, USA). The NASA A-Train is a unique afternoon constellation including a high value series of instruments (Aqua (2002), Aura (2004), PARASOL (2004), CALIPSO (2006), CloudSat (2006), GCOM-W1 (2012) and OCO-2 (2014)) observing our atmosphere.

Julien Chimot was honoured to give a talk, on Thursday 20 April on our recently achieved developments related to the OMI aerosol layer height neural network development (Chimot et al., 2017) and its applications to urban pollution and biomass burning events.This work has been published in the AMT journal in Mars 2017

Many exchanges allow me to think further about 1) the difficulties, even for LIDAR space-borne sensors, to entirely probe smoke aerosol layers, 2) the possibility to inter-compare OMI and OCO-2 aerosol layer height products in the future.

A lot of talks and posters were focused on their contributions to our aerosol and cloud cycle knowledge, and the forthcoming new generation of satellite instruments such as 3MI on MetOp-SG and the new LIDAR EarthCare. Discussions were also held on the recently launched Chinese mission TANSAT, devoted to CO2 observation, which plans to join the constellation soon. With the American mission OCO-2, there will be 2 satellite missions focusing on the atmospheric carbon cycle!

Finally, it is worth noting the very interesting & inspiring discussion led by Dr. Bruce Wieliecki on the economic value of climate science. Obviously, this is a burning and still very open topic. And it is hard to reach a consensus in our community. But if we want to convince the society with business key words, the (huge!) return of investment of a new climate observing system should then be more quantitatively emphasized to initiate concrete actions.

Great thanks to all the organizers of this symposium (in particular to Liz Juvera) and to all the instrument PIs of the A-Train constellation!


2 weeks later. A poster was displayed by Dr. Pieternel Levelt at EGU 2017. See more details at

More information?

  • 3rd NASA A-Train symposium 2017 here
  • Talk at the 3rd NASA A-Train symposium: Chimot J., Veefkind P., Vlemmix T., de Haan J., Levelt P., Aerosol layer height retrieval from OMI+MODIS – A neural network approach, 3rd NASA A-Train symposium, Pasadena, California, USA, 2017.04.20 (Talk) here
  • Chimot et al., 2017: Chimot, J., Veefkind, J. P., Vlemmix, T., de Haan, J. F., Amiridis, V., Proestakis, E., Marinou, E., and Levelt, P. F.: An exploratory study on the aerosol height retrieval from OMI measurements of the 477  nm O2 − O2 spectral band using a neural network approach, Atmos. Meas. Tech., 10, 783-809, doi:10.5194/amt-10-783-2017, 2017 here
  • Follow & @JChimotResearch

The entrance of the Pasadena convention centre, with the banner of the symposium.

Pasadena (California, USA) city-hall

Badge at the 3rd NASA A-Train symposium

Front slide of Julien Chimot talk at the 3rd NASA A-Train symposium, Pasadena (California, USA), 2017.04.20.

Jun 222015
In view of preparing the future European operational satellite missions  dedicated to the atmosphere sounding, the European Space Agency (ESA) organised the ATMOS 2015 conference in at the university of Crete (Greece – Heraklion). This workshop allowed to exchange about retrieval techniques and harmonization of dataset  derived from past and present space-borne atmospheric missions (e.g. GOME, SCIAMACHY, MIPAS, GOMOS, OMI, IASI etc…) and application projects (e.g. Climate Change Initiative, Copernicus). Different sessions were organised about specific topics (greenhouse gases, reactive trace gases and air quality, limb missions). A strong focus was given on the crucial steps to be led by ESA for the successful  preparations of the Sentinel-4 and Sentinel-5 missions (scheduled between 2020 and 2021), the next TROPOMI mission on Sentinel-5 Precursor (before Summer 2016) and the competition between CarbonSat and FLEX missions with a final decision to be taken in September 2015. Around 200 researchers involved in the measurements of atmospheric trace gases, aerosols and clouds from passive satellite sensors were present.
Julien Chimot, PhD in the Atmosphere research team of the GRS department, had the opportunity to present his poster about the impact of aerosol particles on the quantification of  NO2 concentrations in the troposphere from the OMI measurements. This poster relies on a paper recently submitted to the AMT journal (Atmospheric Measurement Technique).
more information can be found on the following websites:
– ATMOS 2015:
– Competition between CarbonSat and FLEX:
– the TROPOMI project:

Julien Chimot
Mar 132012


ePort – an interactive and user friendly layout of ground based and space borne atmospheric observations has found its way to the public. EUMeTrain project has made a large data quantity and weather analysis for Europe available online, updated every 6 hours. ePort is a product of EUMeTrain which is developed to allow you to combine a range of EUMETSAT satellite images with satellite derived
products and numerical model fields.

Project overview link –>

Go to last updated measurements now!

The principle goal of EUMeTrain is to provide users of EUMETSAT satellite data and products that will assist them to make more effective use of it, either as stand-alone material or in combination with other meteorological data sources. This is done by allowing the user to select the variable of interest and plot it for the selected domain/location with a single mouse click. It can be infra-red/visible channel of Meteosat Second Generations satellite, extreme weather warnings (ESTOFEX), 10 meter height wind speeds, CAPE (Convective Available Potential Energy), sounding data, vertical cross sections cloud cover, etc.

The project team consists of the national meteorological services of Austria (ZAMG), Croatia (DHMZ), Finland (FMI), Germany (DWD) and
Portugal (IM).

Mar 022012

An innovative Satellite Report format for synoptic/regional weather analysis, as observed using Meteosat Second Generation satellite imagers, has been introduced and hosted by the KNMI web site. Observed cloud pattens are explained and correlated to the regional scale atmosphere dynamics, such as: front positioning, jet streams, types of precipitation, cloud types identification, etc.

Link: —>

Initially started at the Austrian Meteorological Institute (ZAMG), SatRep project further developed with the co-operation of the European Meteorological Satellite Organisation EUMETSAT, the Netherlands Meteorological Institute (KNMI) and the Finnish Meteorological Institute (FMI).

SatRep can be used for nowcasting (weather forecasting in the coming 3-4 hours), and as an additional source of current/archive weather situation for the end user, compared to typical amount of information one can extract provided satellite images alone.

Mar 022011

 The European Space Agency (ESA) EarthCARE mission has  the green light  to go on and it will be in space not before 2016.

You can read the articles about this news on BBC: 

Article 1

Article 2


EarthCARE Satellite


You can have more information about the ESA-EarthCARE satellite mission on the following webpage:

or you can send an email to