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June 2017:

Vertical Colum Densities of NO2

Vertical Colum Densities of NO2 measured above Bucharest on Monday 2014-09-08. Numbered labels correspond to industrial point source emitters of NOx listed in the European Pollutant Release and Transfer Register ( Black lines indicate major roads.

Vertical Colum Densities of NO2 measured above Bucharest on Monday 2014-09-08

Global maps of nitrogen dioxide (NO2) pollution are nowadays routinely produced from data of satellites such as GOME, SCIAMACHY, OMI and GOME-2. A similar instrument installed on an aircraft results in the same type of maps of tropospheric NO2columns, but with a much higher spatial resolution. During the AROMAT (Airborne Romanian Measurements of Aerosols and Trace gases) campaign which took place in Romania in summer 2014, the AirMAP instrument was installed on board of a Cessna operated by the FU Berlin and took such measurements above Bucharest on several days with a spatial resolution of the order of 100m. The image shows an example of the resulting maps , demonstrating the degree of spatial variability found in an area comparable to just a single pixel of a current state of the art satellite instrument. Comparison between measurements taken at different times and on different days also illustrates large temporal variations, underlying the need for geostationary satellites which can provide several measurements per day for the same location.

The AirMAP instrument is an imaging DOAS spectrometer covering either a band in the visible for high sensitivity NO2retrievals, or a spectral range more in the UV enabling simultaneous detection of SO2and NO2, albeit at lower signal to noise ratio. Data analysis employs the Differential Optical Absorption Spectroscopy (DOAS) method and air mass factors (AMF) based on surface reflectance values derived from the measurements of the AirMAP instrument. Validation of the AirMAP NO2columns with MAX-DOAS measurements from cars operated at the same time during the campaign by the Max-Planck Institute for Chemistry in Mainz and the University of Galati, Romania showed very good agreement, in particular for those measurements for which the time difference was small.

High resolution maps of tropospheric NO2can be used for a variety of applications, including satellite validation, analysis of the representativeness of low spatial resolution observations, emission estimates, and pollution mapping. The AirMAP instrument has already been operated during several other campaigns and it is planned to also employ it for validation of the upcoming Sentinel-5 precursor satellite.

More details can be found in:
Meier, A. C., Schönhardt, A., Bösch, T., Richter, A., Seyler, A., Ruhtz, T., Constantin, D.-E., Shaiganfar, R., Wagner, T., Merlaud, A., Van Roozendael, M., Belegante, L., Nicolae, D., Georgescu, L., and Burrows, J. P.: High-resolution airborne imaging DOAS measurements of NO2 above Bucharest during AROMAT, Atmos. Meas. Tech., 10, 1831-1857, doi:10.5194/amt-10-1831-2017, 2017.

May 2017:

Bremen composite Mg II index

Der Mg II Index ist ein Proxy für die Variabilität der solaren UV Strahlung, die mit der Sonnenaktivität variiert. Neben dem 11-Jahre Zyklus (Schwabe-Zyklus) verändert sich die solare UV Strahlung auch mit der Rotationsperiode der Sonne, die im Mittel etwa 27 Tage beträgt (Carrington-Zyklus). Der Mg II Index korreliert mit der Anzahl der Sonnenflecken, die vom solaren Minimum zum Maximum eines 12-Jahreszyklus zunimmt. Zur Zeit nähern wir uns dem solaren Minimum des nächsten Sonnenzyklus (Zyklus 25). Der Schwabe-Zyklus unterliegt Schwankungen in der Länge (10-12 Jahre) und der Intensität. Das Aktivitätsmaximum des Schwabe-Zyklus 24 (2014/15) war niedriger als die der drei vorherigen Zyklen 21 bis 23.

Der Mg II index wird bei uns aus den täglichen Sonnenmessungen der Satelliteninstrumente GOME, SCIAMACHY, GOME-2A, und -2B seit 1995 abgeleitet. Zusammen mit anderen Satellitendaten kann ein kombinierter Datensatz (´´Composite Mg II Index´´) erstellt werden, der etwa 38 Jahre umfasst (1978-2017) und sich über die Sonnenzyklen 21 bis 24 erstreckt. Diese Zeitserie wird täglich aktualisiert und aktuelle Daten und Bilder sind abrufbar unter http://www.iup.uni-

Die UV Strahlung und deren Variation (Sonnenaktivität) hat einen starken Einfluss auf das stratosphärische Ozon und bestimmt die thermische Struktur der oberen Stratosphäre und beeinflusst damit die globale Luftzirkulation in der oberen Atmosphäre (oberhalb von 20 km).

April 2017:

Evolution of the volcanic plume after the Sarychev Peak eruption

Plots show zonal monthly mean aerosol extinction coefficients at 750 nm retrieved from SCIAMACHY limb measurements at the University of Bremen (V1.4). The volcanic plume is found to reach about 21 km altitude.

July 2009: the month just after the eruption of the Sarychev Peak (48oN, 153oE; June 11-21, 2009). A moderate increase of the stratospheric aerosols is seen around 50oN latitude.

October 2009: aerosol extinction is strongly increased, the plume is transported mostly equatorward.

December 2009: the aerosol load begins to decrease, tropical region is close to the background state.

May 2010: about 1 year after the eruption, the aerosol loading returns to its background state southwards from 50oN

March 2017:

Changes of stratospheric methane 2003 – 2011

Next to carbon dioxide (CO2), methane (CH4) is the most important anthropogenic greenhouse gas. It is produced in the lower atmosphere (the troposphere). Because of its long lifetime, it is eventually transported into higher altitudes, the stratosphere.

The figure (from Noël et al., 2016) shows the changes of stratospheric methane between 2003 and 2011 at Northern mid-latitudes derived from solar occultation measurements of the SCIAMACHY instrument on the ENVISAT satellite. The data have been averaged over one month, and seasonal variations have been removed, resulting in the displayed ‘anomalies’. This way, non-regular and long-term variations in the data become more visible.

In the current case, no clear methane trend for the period 2003 to 2011 can be identified, but there is a prominent variation between positive (red) and negative methane (blue) anomalies. This feature can be explained by transport effects related to the so-called quasi-biennial oscillation (QBO). The QBO is a change of stratospheric winds from easterly to westerly (and vice-versa) which occurs approximately every two years.


Noël, S., K. Bramstedt, M. Hilker, P. Liebing, J. Plieninger, M. Reuter, A. Rozanov, C. E. Sioris, H. Bovensmann and J. P. Burrows, Stratospheric CH4 and CO2 profiles derived from SCIAMACHY solar occultation measurements, Atmos. Meas. Tech., 9(4), 1485-1503, 2016, doi: 10.5194/amt-9-1485-2016,

February 2017:

Indonesia experienced an exceptional number of fires in 2015 as a result of droughts related to an El Niño event. This situation was further intensified by human activities such as clearing of rain forests and drainage of peat land. These fires released large amounts of the greenhouse gas carbon dioxide (CO2) into the atmosphere. Emission databases such as the Global Fire Assimilation System (GFASv1.2) and the Global Fire Emission Database (GFEDv4s) estimated the CO2 emission to be approximately 1100 Mt CO2 in the time period from July to November 2015, which is more than the yearly anthropogenic CO2 emission of an industrialised country such as Germany. The emission from the database was indirectly estimated by using parameters like burned area, fire radiative power, and emission factors but not directly from CO2measurements.

In a recent study, the Indonesian fire CO2 emission is estimated by using CO2 concentrations derived from measurements of the Orbiting Carbon Observatory-2 (OCO-2) satellite mission. The estimated CO2 emissions for the Indonesian fires in the time period from July to November 2015 are shown in the figure above (bars to the right) based on OCO-2 (red, dark red columns are the satellite based CO2 emissions obtained by using two different methods) compared to the GFASv1.2 (light grey) and GFED4s emissions (dark grey). Shown is also the spatial distribution of the fire CO2 emissions based on GFASv1.2. The mean emission based on the satellite CO2 data is 748±296 MtCO2, which is about 30% lower than provided by the emission databases. More details about this study can be found in the publication of Heymann et al., 2017 (

January 2017


Part of the IUP-UB CINDI-2 team in front of the containers in which the DOAS instruments were operated.

IUP-UB participation in the CINDI-2 campaign

In September 2016, the Second Cabauw Intercomparison of Nitrogen measuring Instruments (CINDI-2) took place in Cabauw, the Netherlands. This campaign brought together more than 30 groups from all over the world to compare instruments and analysis methods for quantifying tropospheric and stratospheric NO2amounts. Most of the groups performed different versions of Differential Optical Absorption Spectroscopy (DOAS) measurements using sun light scattered in the atmosphere. The measurements had to follow a strict prescribed protocol and results from a day of measurements were submitted the next morning to a referee who collected them in a semi-blind comparison. The results were presented and discussed during daily meetings but curves were not labelled to keep the comparison semi-blind. A detailed analysis is currently being prepared and will be finalised during a dedicated workshop in April 2017.

During the CINDI-2 campaign, IUP-UB deployed not only a standard 2d-MAX-DOAS instrument and a mobile DOAS instrument mounted on the IUP Messwagen, but for the first time also operated the new Imaging DOAS instrument called IMPACT. This instrument which is a collaboration between the LAMOS and DOAS groups at IUP-UB takes a full vertical scan instantaneously, and scans the azimuthal direction over time. This greatly reduces the time needed for a full hemispherical scan of the atmospheric radiation field to less than 15 minutes. From these measurements, both the horizontal and the vertical gradients of NO2can be retrieved at high temporal resolution. The results could be compared to the retrievals from the 2d-MAX-DOAS instrument and good agreement was found. The instrument will be used for the analysis of pollution plumes and localised emission sources.

Figure: First Comparison of NO2 slant columns derived from the IUP-UB 2d MAX-DOAS instrument (large points) and the IMPACT imaging DOAS instrument. Very good agreement is found with the exception of the lowest viewing angle which is sensitive to the larger field of view of the imaging instrument. The much better temporal resolution of the imaging instrument is apparent which took 11 individual scans during one single scan of the MAX-DOAS instrument. As can be seen from the temporal evolution of the imaging data, the NO2distribution was not constant over the measurements, highlighting the advantage of rapid measurements.

August 2016

Prof. John P. Burrows

elected Fellow of the Royal Society

On 15th July 2016, Prof. John P. Burrows was admitted into the
Royal Society together with 59 other new fellows and foreign members in
a formal ceremony known as „Admission Day“. The ceremony is preceded
by a 2-day seminar where the new fellows give a talk about their current
research. The image shows a collage of pictures taken during Admission Day.

Prof. Dr. John P. Burrows FRS
With Venki Ramakrishnan, President of the Royal Society
The new fellows and foreign members for 2016/
Prof. Burrows 5th from the right, top row
4) Prof . Burrows signing the Charter Book.

December 2015

The left figure

shows in red the CO2 plumes from the city of Berlin and two near by coal fired plants, it would be detected by CarbonSat (Foto Berlin: Thomas Wolf, , Foto Jänschwalde: RaBoe/Wikipedia).

University of Bremen, 2. Dezember 2015

European Commission’s Experts recommend University of Bremen’s concept for quantifying greenhouse gas emissions from space

The European Union Copernicus Climate Change Service recently identified the lack of an operational monitoring system for man-made CO2emissions. This is of major relevance for the upcoming climate conference of the UN Framework Convention on Climate Change in Paris in December. A group of external experts brought together by the European commission was asked to assess the need and opportunity for an independent European space-borne CO2observational capacity to monitor and verify the compliance of parties to international climate agreements. Their report was released recently (see web link) and presented in Brussels in November. The expert group identified the space and ground segment required to deliver surface emissions for monitoring and treaty verification purposes. The report proposes and recommends a concept similar to the CarbonSat concept which was developed and published by researchers at the Institute of Environmental Physics of the University of Bremen. This concept uses the imaging of greenhouse gas “plumes” observed from space to determine the emissions from cities and strong local point sources. The concept builds on the success of a previous Bremen instrument called SCIAMACHY, which flew on ENVISAT 2002 to 2012 and made the first measurements of the atmospheric loading of CO2and CH4but at low spatial resolution. The high spatial resolution concept has been demonstrated by researchers of the University of Bremen using airborne measurements.

In two events in November the European vision of an operational CO2monitoring concept was presented first to members of the European parliament and then to the Copernicus User Forum. The required space segment for CO2monitoring will yield accurate, transparent and consistent quantification of fossil CO2emissions and their trends at the spatial scale of megacities, important industrial sites, small regions, countries, and the Earth as a whole. This capability would provide Europe with a unique and independent source of actionable information for all stages of the policy cycle. Furthermore, the data from a CarbonSat-type mission provides an objective independent contribution to a future international global carbon observing system. The researchers of the Institute of Environmental Physics of the University of Bremen are well prepared to contribute to the implementation of the CarbonSat concept.
Discussions will be held between ESA and the European Commission to investigate flying a Carbon Monitoring satellite within the EU Copernicus Sentinel programme – the suite of satellite sensors being launched by Europe to routinely observe the Earth. It is probable that ESA, whereas not selecting CarbonSat as Earth Explorer, will ask its member states at the agency's next ministerial meeting end of 2016 to fund a Carbon Monitoring prototype satellite to allow Europe for an independent view on CO2emissions.

In conclusion, the global monitoring of CO2emissions by a “CarbonSat type” system is accepted and the issue is now the political will to develop this important system.
Web-Links European Commission, COPERNICUS

WWW-Link CarbonSat@Universität Bremen

WWW-Link: MAMAP@Universität Bremen:

Institut für Umweltphysik
Universität Bremen

Prof. Dr. John P. Burrows
Fon: 0421 218 62100

Dr. Heinrich Bovensmann
Fon: 0421 218 62102

October 2015

click for full size pdf poster

Young Scientist Jia Jia wins “Best Poster” at Atmospheric Limb Workshop

The Atmospheric Limb Workshop is a biennialevent involving more than 8 countries. The scientific focuses are theLimbmeasurements: Emission (UV, visible, IR, microwave), occultation (solar, stellar, lunar), scattering; past, current and future space-borne instruments: SMR, OSIRIS, ACE, GOMOS, MIPAS, SCIAMACHY, SMILES, SAGE, SABER, MLS, SOFIE, HIRDLS, OMPS, ALTIUS, MATS, STEAM; observations and modellingatMesosphere and above, stratosphere, UTLS and troposphere; retrieval algorithms and data assimilation; radiative transfer and spectroscopy. This year it took place from 15 to 17 September in Chalmers University of technology in Gothenburg, Sweden. Like many scientific events, a young scientist award is set for best oral and poster presentations among the PhD student and early stage postdocs. 25 candidates participated in the poster competition. These candidates come from 14 institutes and universities (e.g., JPL, NASA, KIT, NICT, University of Saskatchewan) from 6 countries - Canada, Germany, US, Sweden, Japan, and India. Jia Jia in our institute participated in the competition and won the best poster.

Jia comes from Shandong province in China. She joined IUP in October 2011 to optimize the SCIAMACHY Limb Nadir Matching method in tropospheric ozone retrieval with the funding from CSC (China Scholarship Council) scholarship. The tropospheric ozone monthly data is well improved with the benefitof the V3.0 limb ozone profile information. In this Limb Workshop, she showed the ozonesonde validation of improved SCIAMACHY limb ozone data on a global scale. The newly developedV3.0 limb dataset has a better agreement with ozonesonde in both vertical structure and partial column, especially in the Northern high latitudes. This work is also published in AMT.


September 2015:

European and Chinese Scientists meet to assess and discuss Atmospheric
Pollution in Europe and China:

The PANDA Marco Polo summer school on Atmospheric Pollution at the Institute of Environmental Physics, University of Bremen23rd –30th August 2015

Recently, the World Health Organization (WHO) reported that one out of eight of
global deaths worldwide is caused by air pollution. The strong economic growth in
China over the past three decades has led to China being the largest emitter of
greenhouse gases. Also, serious regional air quality problems are now found in its
many mega cities, e.g., in Beijing, Shanghai and Hong Kong. At the same time and
as a result of large efforts made over the last three decades, mitigation measures in
industrial production practices and the development of strict legislation have led to
improved air quality in many regions of Europe and the USA. China, in particular, is
faced with the difficult problem of maintaining rapid economic growth whilst reducing
air pollution and improving quality of life. To tackle this problem, much more
quantitative information about the amounts and distribution of pollutants and a better
understating of the smog formation mechanisms are therefore needed to facilitate the
reduction of health threatening emissions from human activities while promoting the
most effective and sustained economic development.

Satellite observations provide an exciting, relatively novel tool for the attribution and
prediction of air quality and for monitoring the dispersion of air pollution. The
Institute of Remote Sensing / Institute of Environmental Physics led by
Professor John P. Burrows has pioneered the measurement of atmospheric
pollution from space-based instrumentation over the last 30 years, working together
with the leading atmospheric modelling and prediction groups. The PANDA
(PArtnership with chiNa on space DAta) project, supported by the European
Commission, is a consortium of 7 European laboratories and 7 Chinese research
groups. It provides the evidence base from measurements and modelling to improve
our knowledge on the formation and fate of air pollution required for the development
of adequate environmental policies for clean air and sustainable development.
PANDA is led by Prof. Guy Brasseur from Max Planck Institute of Meteorology
Hamburg, and comprises scientific partners from Universities and research
centres in Europe and China.

As part of PANDA and its European sister project Marco Polo, more than 40 early
career scientists, primarily from China and Europe, participated in a summer
research school from the 23rd to the 30th August, 2015, at the Institute of
Environmental Physics of the University of Bremen. The latest research results from
space-based remote sensing and atmospheric modelling together with the
interpretation of observations were central themes of the summer school. The topics
ranged from the fundamentals of remote sensing and atmospheric modelling to the
estimation of anthropogenic emissions and the impact of economic development and
legislation on air quality. The objective of this summer school and its counterpart
which will be held next year in Chain is to reinforce cooperation between scientists of
China and Europe to jointly address complex questions related to air pollution, and
climate change.

Link: Meeting Programme

August 2015:

This picture shows the change in sulphur content in ship fuels. Before the regulation change on January 1st2015, ships were allowed to use fuels with 1% sulphur content, since this date only much cleaner fuel with 0.1 % is allowed. Data was obtained by measuring exhaust gases of ships with in-situ instruments from a land-based measurement station in Wedel near Hamburg at the Elbe River. This method allows a monitoring for compliance of a large number of ships without having to enter the ships and take fuel samples. Within about 3 months of collecting data, 1413 ships could be analysed for their fuel sulphur content and 95 % of all ships analysed in January comply with the new, much stricter regulations. The measurements were carried out within the project “MeSmarT”, a cooperation between the IUP, Bremen, and the Bundesamt für Seeschifffahrt und Hydrographie, Hamburg.


Press release:

April 2015:

First detection of a large scale methane plume extending several kilometers over a southern
California Oil Field using passive airborne remote sensing. The measurement was performed on
September 04, 2014 with the MAMAP sensor developed at the Institute of Environmental Physics –

The data was acquired in summer 2014 during the COMEX-Campaign, a jointly funded ESA and NASA
project. The European MAMAP remote sensing sensor developed and operated by the Institute of
Environmental Physics at the University of Bremen in cooperation with the German Research Centre
for Geosciences (GFZ) was installed on a Twin Otter aircraft operated by the Center for
Interdisciplinary Remotely-Piloted Aircraft Studies CIRPAS. The instrument detected during several
flights unexpectedly large methane plumes over an Oil field in southern California, which could be
traced over a distance of several kilometers. These measurements demonstrate for the first time
that strong local methane emissions from Gas and Oil production could be detected by passive
remote sensing and traced in space. The data will be used to estimate the magnitude of the emissions resulting from such facilities.

See also press release of the University of Bremen :

Additional pictures are available at:

February 2015

This image was featured by ESA in a web-story entitled “Is Europe an underestimated sink for carbon dioxide?
A new study using satellite data suggests that Europe’s vegetation extracts more carbon from the atmosphere than previously thought. The complete study authored by Maximilian Reuter et al. was published recently in Atmospheric Chemistry and Physics.

December 2014

click image for full resolution

This cover picture was published recently in the AGU journal Earth's Future (

The composite image comprises the following:

a) the night-time image of light coming from the earth, using data acquired by the Visible Infra-red Imaging Radiometer Suite on-board the Suomi NPP satellite in 2012, and

b) an overlay showing the changes in the methane over the continuously growing oil and gas production regions Bakken, Eagle Ford, and Marcellus. The latter is the difference in column methane between the periods 2006-2008 and 2009-2011 and has been derived from measurements made by the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) satellite instrument. (Night-time lights background NASA / overlay by O. Schneising). SCIAMACHY flies on the ESA Envisat and downlinked measurements from 2002 to 2012 when Envisat failed.

The complete study is published in "Remote sensing of fugitive methane emissions from oil and gas production in North American tight geologic formations"; EARTH'S FUTURE Volume 2, Issue 10, October 2014, Pages: 548–558, Oliver Schneising, John P. Burrows, Russell R. Dickerson, Michael Buchwitz, Maximilian Reuter and Heinrich Bovensmann; Article first published online : 6 OCT 2014, DOI: 10.1002/2014EF000265