G. Helas

Water vapor release from biofuel combustion (2008)

Parmar, R. S., Welling, M., Andreae, M. O., Helas, G.

We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are...

Water vapor release from biofuel combustion (2008)

Parmar, R. S., Welling, M., Andreae, M. O., Helas, G.

We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are...

Modelling the optical properties of fresh biomass burning aerosol produced in a smoke chamber: results from the EFEU campaign (2008)

Hungershoefer, K., Zeromskiene, K., Iinuma, Y., Helas, G., Trentmann, J., Trautmann, T., ...

Evidence for large-scale transport of biomass burning aerosols from sunphotometry at a remote South African site (2008)

Winkler, H., Formenti, P., Esterhuyse, D. J., Swap, R. J., Helas, G., Annegarn, H. J., ...

Water vapor release from biomass combustion (2008)

Parmar, R. S., Welling, M., Andreae, M. O., Helas, G.

Size distribution, shape, and composition of mineral dust aerosols collected during the African Monsoon Multidisciplinary Analysis Special Observation Period 0: Dust and Biomass-Burning Experiment field campaign in Niger, January 2006 (2008)

Chou, C., Formenti, P., Maille, M., Ausset, P., Helas, G., Harrison, M., ...

Optical properties of internally mixed ammonium sulfate and soot particles-a study of individual aerosol particles and ambient aerosol populations (2008)

Worringen, A., Ebert, M., Trautmann, T., Weinbruch, S., Helas, G.

Surface features on Sahara soil dust particles made visible by atomic force microscope (AFM) phase images (2008)

Helas, G., Andreae, M. O.

Modelling the optical properties of fresh biomass burning aerosol produced in a smoke chamber: results from the EFEU campaign (2008)

K. Hungershoefer, K. Zeromskiene, Y. Iinuma, G. Helas, J. Trentmann, T. Trautmann, ...

A better characterisation of the optical properties of biomass burning aerosol as a function of the burning conditions is required in order to quantify their effects on climate and atmospheric...

Water vapor release from biomass combustion (2008)

R. S. Parmar, M. Welling, M. O. Andreae, G. Helas

We report on the emission of water vapor from biomass combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are...

Water vapor release from biofuel combustion (2008)

R. S. Parmar, M. Welling, M. O. Andreae, G. Helas

We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are...

Modelling the optical properties of fresh biomass burning aerosol produced in a smoke chamber: results from the EFEU campaign (2007)

Hungershöfer, K., Zeromskiene, K., Iinuma, Y., Helas, G., Trentmann, J., Trautmann, T., ...

A better characterisation of the optical properties of biomass burning aerosol as a function of the burning conditions is required in order to quantify their effects on climate and atmospheric...

Modelling the optical properties of fresh biomass burning aerosol produced in a smoke chamber: results from the EFEU campaign (2007)

Hungershöfer, K., Zeromskiene, K., Iinuma, Y., Helas, G., Trentmann, J., Trautmann, T., ...

A better characterisation of the optical properties of biomass burning aerosol as a function of the burning conditions is required in order to quantify their effects on climate and atmospheric...

Source characterization of biomass burning particles: The combustion of selected European conifers, African hardwood, savanna grass, and German and Indonesian peat (2007)

Iinuma, Y., Brüggemann, E., Gnauk, T., Müller, K., Andreae, M. O., Helas, G., ...

Modelling the optical properties of fresh biomass burning aerosol produced in a smoke chamber: results from the EFEU campaign (2007)

Hungershöfer, K., Zeromskiene, K., Iinuma, Y., Helas, G., Trentmann, J., Trautmann, T., ...

Physical, chemical and optical properties of aerosol particles collected over Cape Town during winter haze episodes (2007)

Gwaze, P., Helas, G., Annegarn, H. J., Huth, J., Piketh, S. J.

Comparison of particle sizes determined with impactor, AFM and SEM (2007)

Gwaze, P., Annegarn, H. J., Huth, J., Helas, G.

Modelling the optical properties of fresh biomass burning aerosol produced in a smoke chamber: results from the EFEU campaign (2007)

K. Hungershöfer, K. Zeromskiene, Y. Iinuma, G. Helas, J. Trentmann, T. Trautmann, ...

A better characterisation of the optical properties of biomass burning aerosol as a function of the burning conditions is required in order to quantify their effects on climate and atmospheric...

Comparison of three methods of fractal analysis applied to soot aggregates from wood combustion (2006)

Gwaze, P., Schmid, O., Annegarn, H. J., Andreae, M. O., Huth, J., Helas, G.

Mass spectrometric analysis and aerodynamic properties of various types of combustion-related aerosol particles (2006)

Schneider, J., Weimer, S., Drewnick, F., Borrmann, S., Helas, G., Gwaze, P., ...

Aerosol extinction in a remote continental region of the Iberian Peninsula during summer (2006)

Elias, T., Silva, A. M., Belo, N., Pereira, S., Formenti, P., Helas, G., ...

"Missing" cloud condensation nuclei in peat smoke (2005)

Dusek, U., Frank, G. P., Helas, G., Iinuma, Y., Zeromskiene, K., Gwaze, P., ...

Measurement of wavelength-resolved light absorption by aerosols utilizing a UV-VIS extinction cell (2005)

Schnaiter, M., Schmid, O., Petzold, A., Fritzsche, L., Klein, K. F., Andreae, M. O., ...

Laboratory measurements of smoke optical properties from the burning of Indonesian peat and other types of biomass (2005)

Chand, D., Schmid, O., Gwaze, P., Parmar, R. S., Helas, G., Zeromskiene, K., ...

Biomass burning in Africa: role in atmospheric change and opportunities for emission mitigation (2005)

Kituyi, E., Wandiga, S. O., Andreae, M. O., Helas, G.

Measurement of wavelength-resolved light absorption by aerosols utilizing a UV-VIS extinction cell. (2005)

Schnaiter, M., Schmid, O., Petzold, A., Fritzsche, L., Klein, K.F., Andreae, M.O., ...

Aerosol Science and Technology, 39(2005) S.249-60

Impact of vegetation fires on composition and circulation of the atmosphere (EFEU) (2004)

Wurzler,S., Simmel,M., Diehl,K., Hennig,T., Herrmann,H., Iinuma,Y., ...

The project addresses the contribution of vegetation fires to the local trace gas and particle budgets of the troposphere and the lower stratosphere, their direct and indirect radiative impact, their...

Impact of Vegetation Fires on the Composition and Circulation of the Atmosphere (2004)

Simmel, Martin, Wurzler, Sabine, Diehl, Karoline, Hennig, T., Herrmann, H., Iinuma, Yoshiteru, ...

Vegetation fires are a significant source for atmospheric trace gases and aerosol particles (APs) on both local and global scale. The biomass burning APs affect cloud formation as well as...

Impact of vegetation fires on composition and circulation of the atmosphere (EFEU) (2004)

Wurzler, S., Simmel, M., Diehl, K., Hennig, T., Herrmann, H., Iinuma, Y., ...

The project addresses the contribution of vegetation fires to the local trace gas and particle budgets of the troposphere and the lower stratosphere, their direct and indirect radiative impact, their...

Domestic combustion of biomass fuels in developing countries: A major source of atmospheric pollutants (2003)

Ludwig, J., Marufu, L. T., Huber, B., Andreae, M. O., Helas, G.

Aerosol optical depth over a remote semi-arid region of South Africa from spectral measurements of the daytime solar extinction and the nighttime stellar extinction (2002)

Formenti, P., Winkler, H., Fourie, P., Piketh, S., Makgopa, B., Helas, G., ...

Spectral daytime aerosol optical depths have been measured at Sutherland, South Africa (32degrees22' S, 20degrees48' E), from January 1998 to November 1999. Sutherland is located in the semi-arid...

Complex refractive index of aerosols during LACE 98 as derived from the analysis of individual particles (2002)

Ebert, M., Weinbruch, S., Rausch, A., Gorzawski, G., Hoffmann, P., Wex, H., ...

[1] During the Lindenberger Aerosol Characterization Experiment (LACE 98), impactor sampling of aerosol particles in the size range of 0.1 to 25 mum was performed. The atmospheric concentrations of...

Carbon monoxide and nitric oxide from biofuel fires in Kenya (2001)

Kituyi, E., Marufu, L., Wandiga, S. O., Jumba, I. O., Andreae, M. O., Helas, G.

Biofuel consumption rates and patterns in Kenya (2001)

Kituyi, E., Marufu, L., Huber, B., Wandiga, S. O., Jumba, I. O., Andreae, M. O., ...

Biofuel availability and domestic use patterns in Kenya (2001)

Kituyi, E., Marufu, L., Wandiga, S. O., Jumba, I. O., Andreae, M. O., Helas, G.

Calculation of scattering and absorption of light by irregular shaped and mixed particles. (2001)

Rausch, A., Trautmann, T., Weinbruch, S., Helas, G.

Characterization and transport of aerosols over equatorial eastern Africa. (2001)

Gatebe, C. K., Tyson, D., Annegarn, H. J., Helas, G., Kinyua, A. M., Piketh, S. J.

The complex refractive index of aerosols during LACE 98 as derived from the analysis of indivi-dual particles. (2001)

Ebert, M., Weinbruch, S., Rausch, A., Gorzawski, G., Wex, H., Hoffmann, P., ...

Photochemistry of the African troposphere: The influence of biomass burning emissions (2000)

Marufu, L, Dentener, F, Lelieveld, J, Andreae, M O, Helas, G

Distribution of aerosols, ozone and carbon monoxide over southern Africa (2000)

Kirkman, G A, Piketh, S J, Andreae, M O, Annegarn, H J, Helas, G

A global database of sea surface dimethylsulfide (DMS) measurements and a simple model to predict sea surface DMS as a function of latitude, longitude and month (1999)

Kettle, A. J., Andreae, M. O., Amouroux, D., Andreae, T W, Bates, T. S., Berresheim, H., ...

Spatial and temporal variation in biofuel consumption rates and patterns in Zimbabwe: Implications for atmospheric trace gas emission (1999)

Marufu, L, Ludwig, J, Andreae, M O, Lelieveld, J, Helas, G

Trace gas distribution in the tropopause region: First results from the STREAM-98 summer campaign in Timmins, Canada. (1999)

Fischer, H., Brunner, D., Harris, G. W., Helas, G., Hoor, P., Lange, L., ...

Giant dendritic carbonaceous particles in Soweto aerosols. (1999)

Wentzel, M., Annegarn, H. J., Helas, G., Weinbruch, S., Balogh, A. G., Sithole, J. S.

High-resolution scanning electron microscopy of individual aerosol particles obtained during LACE 98. (1999)

Rausch, A., Ebert, M., Gorzawski, G., Weinbruch, S., Hoffmann, P., Helas, G.

Elemental and phase composition of aerosols sampled during LACE 98. (1999)

Gorzawski, G., Rausch, A., Ebert, M., Weinbruch, S., Hoffmann, P., Helas, G.

A seasonal air transport climatology for Kenya. (1999)

Gatebe, C. K., Tyson, P. D., Annegarn, H., Piketh, S., Helas, G.

The great dun fell cloud experiment 1993: An overview (1997)

Choularton, T.W., Colvile, R.N., Bower, K.N., Gallagher, M.W., Wells, M., Beswick, K.M., ...

The 1993 Ground-based Cloud Experiment on Great Dun Fell used a wide range of measurements of trace gases, aerosol particles and cloud droplets at five sites to study their sources and sinks...

Emissions of organic trace gases from savanna fires in southern Africa during the 1992 Southern African Fire Atmosphere Research Initiative and their impact on the formation of tropospheric ozone (1997)

Koppmann, R, Khedim, A, Rudolph, J, Poppe, D, Andreae, M O, Helas, G, ...

Ammonia exchange between terrestrial plants and the atmosphere controlled by plant physiology: Compensation point and CO2 exchange (1997)

Meixner, F. X., Bliefernicht, M., Helas, G., Kesselmeier, J., Wyers, P. G., Andreae, M. O.

Der Einfluß von Vegetationsfeuern und Biomasseverbrennung auf die Atmosphäre (1997)

Helas, G, Marufu, L, Ludwig, J, Goldammer, J G, Andreae, M O

Domestic biomass burning in rural and urban Zimbabwe - Part A (1997)

Marufu, L, Ludwig, J, Andreae, M O, Meixner, F X, Helas, G

A publication of the (1997)

Deutsche Meteorologisc:he Cjesellschaft, J. Heintzenberg, R. J. Charlson, C. Liousse, V. Ramasw Amy, ...

The net effect of atmospheric aerosols in the radiation balwlce is detj~rmined by both their scattering and absorption of solar radiation. The combined optical effect is expressed in the single...

Methyl halide emissions from savanna fires in southern Africa (1996)

Andreae, M O., Atlas, E, Harris, G W, Helas, G, De Kock, A, Koppmann, R, ...

A preliminary global database of sea surface dimethylsulfide measurements and a simple model to predict sea surface dimethyl as a function of latitude, longitude and month (1996)

Kettle, A. J., Andreae, M. O., Amouroux, D., Helas, G., Rapsomanikis, S., Roberts, G., ...

Trace gas and aerosol emissions from savanna fires (1996)

Andreae, M O, Atlas, E, Cachier, H, Cofer, W R, Harris, G W, Helas, G, ...

Methyl halide emissions from savanna fires in southern Africa. (1996)

ANDREAE, MO, ATLAS, E, HARRIS, GW, HELAS, G, DEKOCK, A, KOPPMANN, R, ...

Biomass burning in the tropical savannas of Ivory Coast: An overview of the field experiment Fire Of Savannas (FOS/DECAFE '91) (1995)

Lacaux, J P., Brustet, J M., Delmas, R, Menaut, J C., Abbadie, L, Bonsang, B, ...

Ozone production due to emissions from vegetation burning (1995)

Helas, G, Lobert, J, Scharffe, D, Schäfer, L, Goldammer, J, Baudet, J, ...

Airborne measurements of savanna fire emissions and the regional distribution of pyrogenic pollutants over western Africa (1995)

Helas, G, Lobert, J, Scharffe, D, Schäfer, L, Goldammer, J, Baudet, J, ...

SA'ARI-94: a preliminary view of results (1995)

Helas, G, Andreae, M O, Schebeske, G, Le Canut, P

Airborne measurements of biomass burning products over Africa (1994)

Helas, G, Lobert, J, Goldammer, J, Andreae, M O., Lacaux, J P., Delmas, R

Vegetationsbrände: Auswirkungen auf Ökosysteme, Atmosphäre und Klima (1994)

Goldammer, J G, Andreae, M O, Helas, G, Meixner, F

Biosphere/atmosphere interactions: integrated research in an European coniferous forest ecosystem (1992)

Enders, G., Dlugi, R., Steinbrecher, R., Clement, B., Daiber, R., Eijk, V. J., ...

Behavior of atmospheric formic and acetic acid in the presence of hydrometeors (1992)

Helas, G, Andreae, M O., Hartmann, W R.

Vertical profiles of ozone between 0 - 400 meters in and above the African Equatorial Forest (1992)

Cros, B, Fontan, J, Minga, A, Helas, G, Nganga, D, Delmas, R, ...

Organic acids over equatorial Africa: Results from DECAFE 88 (1992)

Helas, G, Bingemer, H, Andreae, M O.

Sulfur gases and aerosols in and above the equatorial African rainforest (1992)

Bingemer, H G., Andreae, M O., Andreae, T W., Artaxo, P, Helas, G, Jacob, D J., ...

Ozone as biomass burning product over Africa (1992)

Helas, G, Delmas, R, Scharffe, D, Lobert, J, Goldammer, J, ...

Ozone and Aitken nuclei over equatorial Africa: Airborne observations during DECAFE 88 (1992)

Andreae, M. O., Chapuis, A., Cros, B., Fontan, J., Helas, G., Justice, C., ...

Volatile organic acids and ammonia measurements in a spruce forest (1991)

Bingemer, H. G., Ernst, L., Fischer, M., Kesselmeier, J., Andreae, M. O., Helas, G.

Ozone production from biomass burning in tropical Africa. Results from DECAFE-88 (1990)

Andreae, M. O., Helas, G., Rudolph, J., Cros, B., Delmas, R., Nganga, D., ...

Formic and acetic acid in presence of cloud and dew water (1990)

Hartmann, W. R., Andreae, M. O., Helas, G.

Measurements of organic acids over Central Germany (1989)

Hartmann, W. R., Andreae, M. O., Helas, G.

Ozone measurements in equatorial Africa during DECAFE 88 (1989)

Helas, G., Andreae, M. O., Fontan, J., Cros, B., Delmas, R.

Measurements of tropospheric OH concentrations - a comparison of field data with model predictions (1987)

Perner, D., Platt, U., Trainer, M., Hübler, G., Drummond, J., Rudolph, J., ...

Using long path UV absorption spectroscopy we have measured OH concentrations close to the earth's surface. The OH values observed at two locations in Germany during 1980 through 1983 range from 0.7...

Acetonitrile in the troposphere. Residence time due to rainout and uptake by the ocean (1984)

Hamm, S., Hahn, J., Helas, G., Warneck, P.

Henry's law coefficients for the binary system acetonitrilewater are reported as a function of temperature from 279-303 K. The results are used to estimate the tropospheric residence time of...