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14 results on '"Hollwedel, J."'

1. Frost flowers on sea ice - a multi-disciplinary research effort for the upcoming International Polar Year (IPY)

Author

Kaleschke, L., Richter, A., Burrows, J., Heygster, G., Notholt, Justus, Hollwedel, J., von Glasow, R., Wagner, Tanja, Jacobi, Hans-Werner, Herber, Andreas, Weller, Rolf, Sander, R., Roscoe, H. K., Wolff, E. W., Hutterli, M., Jones, A., Yang, X., Carpenter, L., Kaspari, S., Kaleschke, L., Richter, A., Burrows, J., Heygster, G., Notholt, Justus, Hollwedel, J., von Glasow, R., Wagner, Tanja, Jacobi, Hans-Werner, Herber, Andreas, Weller, Rolf, Sander, R., Roscoe, H. K., Wolff, E. W., Hutterli, M., Jones, A., Yang, X., Carpenter, L., and Kaspari, S.

Published
2005

3. Satellite Remote Sensing of Atmospheric SO_2: Volcanic Eruptions and Anthropogenic Emissions

Author

Khokhar, Muhammad Fahim, Frankenberg, C., Hollwedel, J., Beirle, S., Kühl, S., Grzegorski, M., Wilms-Grabe, W., Platt, U., Wagner, Thomas, Khokhar, Muhammad Fahim, Frankenberg, C., Hollwedel, J., Beirle, S., Kühl, S., Grzegorski, M., Wilms-Grabe, W., Platt, U., and Wagner, Thomas

Abstract

In this article, we present satellite data analysis of atmospheric Sulfur Dioxide (SO_2) from volcanic eruptions and anthropogenic activities. Data from Global Ozone Monitoring Experiment (GOME) on board ERS-2 for the years 1996 to 2002 is analyzed using a DOAS based algorithm with the aim of retrieving SO_2 Slant Column Densities (SCDs). Difficulties in the retrieval of SO_2 SCDs due to instrumental effects are investigated in detail and significantly improved. The retrieved SCDs can be used to identify and monitor several volcanic eruptions. A brief introduction of different volcanic eruptions around the globe is presented Also informations about the anthropogenic SO_2 emissions can be easily achieved from the retrieved data set. A time series of anthropogenic SO_2 emissions over Eastern Europe is presented in this study. The time series showed high SO_2 SCDs over Eastern Europe during the winter months. The results demonstrate a high sensitivity of GOME instrument towards SO_2 emissions.

Published
2005

4. Frost flowers on sea ice - a multi-disciplinary research effort for the upcoming International Polar Year (IPY)

Author

Kaleschke, L., Richter, A., Burrows, J., Heygster, G., Notholt, Justus, Hollwedel, J., von Glasow, R., Wagner, Tanja, Jacobi, Hans-Werner, Herber, Andreas, Weller, Rolf, Sander, R., Roscoe, H. K., Wolff, E. W., Hutterli, M., Jones, A., Yang, X., Carpenter, L., Kaspari, S., Kaleschke, L., Richter, A., Burrows, J., Heygster, G., Notholt, Justus, Hollwedel, J., von Glasow, R., Wagner, Tanja, Jacobi, Hans-Werner, Herber, Andreas, Weller, Rolf, Sander, R., Roscoe, H. K., Wolff, E. W., Hutterli, M., Jones, A., Yang, X., Carpenter, L., and Kaspari, S.

Published
2005

6. Frost Flowers on Sea Ice as a Source of Sea Salt and their Influence on Tropospheric Chemistry

Author

Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, Justus, Jacobi, Hans-Werner, Weller, Rolf, Rankin, A. M., Roscoe, H. K., Wolff, E. W., Hollwedel, J., Wagner, Tanja, Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, Justus, Jacobi, Hans-Werner, Weller, Rolf, Rankin, A. M., Roscoe, H. K., Wolff, E. W., Hollwedel, J., and Wagner, Tanja

Published
2004

9. Frost flowers on sea ice as a source of sea salt and their influence on tropospheric halogen chemistry

Author

Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, J., Rankin, A.M., Roscoe, H.K., Hollwedel, J., Wagner, T., Jacobi, H.-W., Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, J., Rankin, A.M., Roscoe, H.K., Hollwedel, J., Wagner, T., and Jacobi, H.-W.

Abstract

Frost flowers grow on newly-formed sea ice from a saturated water vapour layer. They provide a large effective surface area and a reservoir of sea salt ions in the liquid phase with triple the ion concentration of sea water. Recently, frost flowers have been recognised as the dominant source of sea salt aerosol in the Antarctic, and it has been speculated that they could be involved in processes causing severe tropospheric ozone depletion events during the polar sunrise. These events can be explained by heterogeneous autocatalytic reactions taking place on salt-laden ice surfaces which exponentially increase the reactive gas phase bromine ("bromine explosion"). We analyzed tropospheric bromine monoxide (BrO) and the sea ice coverage both measured from satellite sensors. Our model based interpretation shows that young ice regions potentially covered with frost flowers seem to be the source of bromine found in bromine explosion events.

Published
2004

10. Stratospheric chlorine activation in the Arctic winters 1995/96–2001/02 derived from GOME OClO measurements

Author

Burrows, J. P., Thompson, Anne M., Eichmann, K.-U., Kühl, S., Wilms-Grabe, W., Beirle, S., Frankenberg, C., Grzegorski, M., Hollwedel, J., Khokhar, F., Kraus, S., Platt, U., Sanghavi, S., von Friedeburg, C., Burrows, J. P., Thompson, Anne M., Eichmann, K.-U., Kühl, S., Wilms-Grabe, W., Beirle, S., Frankenberg, C., Grzegorski, M., Hollwedel, J., Khokhar, F., Kraus, S., Platt, U., Sanghavi, S., and von Friedeburg, C.

Abstract

In this article, we present satellite observations of OClO from the years 1995–2002. The focus is on observations of OClO in the Arctic wintertime stratosphere, which are compared to results of the SLIMCAT model and to observations in the Antarctic. In particular, we investigated the beginning and ending of the chlorine activation in the Arctic stratosphere. The Slant Column Densities (SCDs) of OClO increase significantly, when the temperature falls below the threshold for formation of Polar Stratospheric Clouds. The time for decrease of the OClO-SCDs in the deactivation phase (early spring) varies strongly and is related to the degree of denitrification. In the Arctic, chlorine activation can be further increased when there is strong activity of stratospheric mountain waves.

Published
2004

11. Frost Flowers on Sea Ice as a Source of Sea Salt and their Influence on Tropospheric Chemistry

Author

Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, Justus, Jacobi, Hans-Werner, Weller, Rolf, Rankin, A. M., Roscoe, H. K., Wolff, E. W., Hollwedel, J., Wagner, Tanja, Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, Justus, Jacobi, Hans-Werner, Weller, Rolf, Rankin, A. M., Roscoe, H. K., Wolff, E. W., Hollwedel, J., and Wagner, Tanja

Published
2004

14. Frost flowers on sea ice as a source of sea salt and their influence on tropospheric halogen chemistry

Author

Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, J., Rankin, A.M., Roscoe, H.K., Hollwedel, J., Wagner, T., Jacobi, H.-W., Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, J., Rankin, A.M., Roscoe, H.K., Hollwedel, J., Wagner, T., and Jacobi, H.-W.

Abstract

Frost flowers grow on newly-formed sea ice from a saturated water vapour layer. They provide a large effective surface area and a reservoir of sea salt ions in the liquid phase with triple the ion concentration of sea water. Recently, frost flowers have been recognised as the dominant source of sea salt aerosol in the Antarctic, and it has been speculated that they could be involved in processes causing severe tropospheric ozone depletion events during the polar sunrise. These events can be explained by heterogeneous autocatalytic reactions taking place on salt-laden ice surfaces which exponentially increase the reactive gas phase bromine ("bromine explosion"). We analyzed tropospheric bromine monoxide (BrO) and the sea ice coverage both measured from satellite sensors. Our model based interpretation shows that young ice regions potentially covered with frost flowers seem to be the source of bromine found in bromine explosion events.

Published
2004

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