Analyses of the trends is possible but overall a challenging and sensitive task. Over 20 years, very different sensor techniques, instrument specificities & degradations, variable pixel sizes, cloud detection possibilities etc… A lot of works to harmonise these data!
Atmosphericaerosol are particles suspended in the air. Their sources are very mixed. Aerosol can be man-made or natural: e.g. smoke, desert dust, sea spray, nitrates and sulfates. The aerosol effects on the sunlight modify the shortwave radiation field in the atmosphere. This directly impacts the climate and the satellite observations devoted to ocean surface, land surface, vegetation, and atmospheric gases. Furthermore, heavy load of aerosols affects our air quality.
In spite of many progresses during the last 10-20 years, aerosol observations from space-borne instruments remain incredibly complex. One of the main reasons is their heterogeneity: aerosols are everywhere, but with very variable quantities spatially (horizontally and vertically!), and temporally. And, as highlighted by this NASA picture, aerosol types are also very heterogeneous! Retrieving all these parameters from single satellite measurements, without ambiguity with respect to surface characteristics and clouds, is the difficult task of the scientists working with atmospheric satellite measurements. Many works to continue to do…
More information
NASA WebPage “Just another Day on Aerosol Earth” here
This paper is based on the last developments we published during 2016, 2017, and 2018. During these years, not only the OMI cloud algorithm was improved (Veefkind et al., 2016), but also an OMIaerosol layer height (and optical thickness) neural network algorithm was developed (Chimot et al., 2017, 2018). This time, we directly evaluate the impacts of these developments to correct of aerosol absorption and scattering effects in the visible spectral range in view of retrieving troposphericNO2, an important trace gas affecting air quality in urban and industrialised areas.
Statistics of relative troposphericNO2 VCD changes in (%) in 2006-2007, due to differences between the different explicit aerosol corrections and the implicit aerosol correction based on OMCLDO2-New: (a), and (b): China summertime (June-July-August), (c), and (d): China wintertime (December-January-February), (e), and (f): South America biomass burning season (August-September).
As part of the Copernicus programme, Sentinel-3 is a very important mission for ocean colour, sea and land surface, fire, atmosphere and climate purposes. With the two platforms, Sentinel-3 A and B, an optimal global coverage will be now obtained. The next observations and related products are promising!
More information?
Check the diverse pictures of this fantastic launch via the Twitter accounts of EUMETSAT and ESA
The current Sentinel-3 services provided by EUMETSAT here
And watch below the movie from EUMETSAT in live in the Sentinel-3 control centre “Sentinel-3: Operating satellites” with Hillary Wilson, EUMETSAT’s Sentinel-3 manager, and Kevin Marston, EUMETSAT’s System operation manager.
This paper is based on the work of 2017, in which a neural network algorithm was developed for retrieving aerosol layer height (ALH) from the OMI O2-O2 visible measurements. This time, we directly compare our retrievals with CALIOPaerosol observations and evaluate the spatial patterns on several remarkable case studies including urban pollution, biomass burning events and a Saharan dust outbreak!
In a world that is continuously evolving, and where it is very difficult to find adequate information about our environment and used observations, my only hope was to share some news about my topics of interest (trace gases, aerosol, air quality, climate), get more reliable information and increase (if possible) my network. I must admit that I was initially a bit skeptical.
But the numbers that I have now somehow surprise me: 3091 visits last year from some 1147 visitors. Since January, already 1127 views from 550 visitors! This may look very little for some people. But for me, this is quite significant! I have no idea whether people really got interest in my work and/or website, or just found a bit by chance some of the webpages.
What is for sure not a coincidence: 96 people connected with me viaTwitter, most of them / you that I don’t really know, and regularly exchanging scientific news with me. And about 56 posts posted alone or with some friends!
I don’t know who you are, and whether you found my HomePage by chance. But for all the scientific news and exciting exchanges that I have, thank you! In spite of my restricted time, I will keep updating this Homepage and my Twitter account on a more or less regular basis!
The Earth observation science journey, using satellites, continues!
Our research works achieved with my colleagues from Geoscience & Remote Sensing (GRS) – TU Delft, and KNMI, before my leaving, will be presented via a poster at EGU 2018. In particular, recent findings and the last publication on the retrieval of aerosol layer height (ALH) from the OMI 477 nm O2-O2 band and using the developed neural network algorithm will be shown
Don’t miss the poster presentation by Prof. Dr. Pieternel Levelt on Monday 09.04 17:30 – 19:00 in Hall X5 at board number X5.170!
Recent results of OMI Aerosol Layer Height Retrieval over East China by Chimot et al. (2018) (just accepted for publication in AMT).
More information?
Abstract EGU2018 “Aerosol layer height from OMI and neural network – Evaluation and possibility of a 13-year time series?” here
