Note: Lena Brinkhoff quit ESSReS as of 31st December 2013 to pursue a career in secondary school education.

Name:              Lena Brinkhoff
Institute:          University of Bremen / IUP
Department:    WG Physics and Chemistry of the Atmosphere
Phone:             +49 (0) 421-218 62088
Email:              brinkhoff@iup.physik.uni-bremen.de
Web link:         http://www.iup.uni-bremen.de/deu/

Stratospheric aerosols are of scientific interest, as they primarily scatter solar radiation, and therefore increase the Earth's planetary albedo. The permanent aerosol background in the stratosphere is due to tropical injection of tropospheric air containing SO2, COS and sulphate particles, which are precursors for stratospheric aerosols. An additional contribution is sporadically caused by an uplift of SO2 after a strong volcanic eruption. Especially after strong volcanic eruptions, the consequential effect of stratospheric aerosols on the Earth's radiation budget is stratospheric warming and tropospheric cooling. Furthermore, they have an impact on stratospheric chemistry: Stratospheric aerosols are precursors for polar stratospheric clouds, and thus support the destruction of ozone inside the polar vortex. They even lead to a halogen-driven ozone destruction outside polar vortices. On account of these properties, stratospheric aerosols concern to the so-called Essential Climate Variables.

From 2002 to 2012, near-global observations of stratospheric aerosols were supplied by SCIAMACHY, which was one of ten instruments onboard the Envisat spacecraft, detecting the sunlight in the wavelength range from 214 to 2386 nm with three different viewing geometries: nadir, limb and occultation. In this PhD project limb-scatter measurements are used. They have the advantage of high vertical resolution, compared to nadir measurements, and a near-global coverage on the dayside of the Earth, in contrast to solar occultation measurements.

The main focus of this PhD project is to improve the algorithm for retrieving stratospheric aerosol extinction profiles from SCIAMACHY limb-scatter observations. The retrieval is performed using an optimal estimation scheme combined with the radiative transfer model SCIATRAN. Further goals are analysing the entire SCIAMACHY stratospheric aerosol dataset and investigating the temporal and spatial variability in stratospheric aerosol extinction as well as the impact of volcanic eruptions and distribution of volcanic aerosol plumes across the globe. Concerning these matters, the PhD project is related to the SPIN (ESA SParc Initiative) project.

So far, the existing SCIAMACHY stratospheric aerosol product (Ernst et al., 2012, AMTD) has been visualised and the variability of the aerosol load has been interpreted. Signatures of volcanic eruption and bushfire events have been identified as well as a seasonal cycle and biennial variation in the aerosol extinction. The improvement of the data quality is planned by using multi-wavelength observations from SCIAMACHY in order to optimise the used phase function, which turned out to be a very influential factor in the retrieval.
 

Start of doctoral thesis: 16th January 2012

Supervisor : Dr. Alexei Rozanov (Uni Bremen)

Co-Supervisor : Prof. Dr. Christian von Savigny (Uni Greifswald)

Further members : Prof. John P. Burrows (Uni Bremen), Dr. Claudia Timmreck (MPI Hamburg), Dr. René Hommel (Uni Bremen)

Committee Meetings: 10.09.2012, 24.05.2013

Ernst, F., von Savigny, C., Rozanov, A., Rozanov, V., Eichmann, K.-U., Brinkhoff, L. A., Bovensmann, H., and Burrows, J. P.: Global stratospheric aerosol extinction profile retrievals from SCIAMACHY limb-scatter observations, Atmos. Meas. Tech. Discuss., 5, 5993-6035, doi:10.5194/amtd-5-5993-2012, 2012.

Helmholtz Research School on Earth System Science, Annual Retreat 2012, Bremerhaven, Germany
L. A. Brinkhoff, F. Ernst, A. Rozanov, C. von Savigny, R. Hommel, and J. P. Burrows: “Retrieval and variability of stratospheric aerosols from SCIAMACHY limb‐scatter“, 30 November 2012

7th International Atmospheric Limb Conference, Bremen, Germany
L. A. Brinkhoff, A. Rozanov, F. Ernst, C. von Savigny, R. Hommel, H. Bovensmann, and J. P. Burrows: "Retrieval and variability of stratospheric aerosols from SCIAMACHY limb-scatter observations", 17-19 June 2013

ESA Atmospheric Science Conference 2012, Bruges, Belgium
L. A. Brinkhoff, F. Ernst, A. Rozanov, C. v. Savigny, and J. P. Burrows: "Retrieval and climatology of stratospheric aerosols from SCIAMACHY limb-scatter observations", 18-22 June 2012

ACVE - Atmospheric Composition Validation and Evolution Workshop, ESA/ESRIN, Frascati, Italy (not present)
L. A. Brinkhoff, F. Ernst, A. Rozanov, C. v. Savigny, K. Weigel (presenter), H. Bovensmann, and J. P. Burrows: "Stratospheric aerosol retrievals from SCIAMACHY limb-scatter obser vations",  13-15 March 2013

European Geosciences Union General Assembly 2013 Vienna,  Austria
L. A. Brinkhoff, F. Ernst, A. Rozanov, C. v. Savigny, R. Hommel, H. Bovensmann, and J. P. Burrows: "Retrieval and variability of stratospheric aerosols from SCIAMACHY limb-scatter observations", 07-12 April 2013

DACA-13 - Davos Atmosphere and Cryosphere Assembly 2013, Davos, Switzerland (not present)
L. A. Brinkhoff, F. Ernst, A. Rozanov, C. v. Savigny, R. Hommel, C. Gebhardt (presenter), H. Bovensmann, and J. P. Burrows: "Variability in the stratospheric aerosol load from SCIAMACHY limb-scatter observations", 8-12 July 2013

ESA Living Planet Symposium 2013, Edinburgh, Scotland
L. A. Brinkhoff, A. Rozanov, F. Ernst, R. Hommel, C. von Savigny, C. Gebhardt, H. Bovensmann, and J. P. Burrows: "Variability in the stratospheric aerosol load from SCIAMACHY limb-scatter observations", 9-13 September 2013

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