Koldewey Station, Ny-Ålesund/Spitsbergen: projects/activities

The project aims at producing an ENVISAT-1 mission-long monitoring of the inorganic chlorine (Cly) and fluorine (Fy) loading in the Earth’s middle atmosphere, based on FTIR vertical column abundance measurements of the key related species HCl, ClONO2, HF and COF2 at 10 ground-based NDSC sites distributed worldwide. These Cly and Fy inventories will be completed with ClO and OClO measurements expected as Level-2 products from ENVISAT-1. The column abundances of the source gases CFC-12 and HCFC-22 will be used to place the stratospheric Cly and Fy evolution in perspective with the more complete sets of organic chlorinated and fluorinated compounds measured at the ground by the in situ networks NOAA-CMDL and AGAGE. The assimilation of the retrieved geophysical data bases will be performed through 3-D model calculations incorporating physical, chemical and transport characteristics of the global atmosphere.

The present project aims at the geophysical validation, from pole to pole and on the long term, of key ozone-related level-2 products (O3, NO2, BrO, OClO, and ClO) from GOMOS, MIPAS and SCIAMACHY onboard ENVISAT-1, and at a contribution to the maturation of the related level-1b-to-2 data processors. Application data processing will be used to convert level-2 data into a more suitable format for validation and scientific end-users. The respective performances of the ENVISAT data products, and their sensitivity to various relevant parameters, will be investigated from the Arctic to the Antarctic, over a variety of geophysical conditions. The impact of these performances on specific atmospheric chemistry studies will be emphasised. The pseudo-global investigations will rely on correlative studies of ENVISAT data with high-quality ground-based, in situ and balloon observations associated with the Network for the Detection of Stratospheric Change (NDSC).

The project will provide a long-term, pseudo-global validation support to the ENVISAT-1 atmospheric measurements, based on mutually consistent high-quality solar and lunar observations from FTIR spectrometers operated at primary and a number of complementary NDSC stations. The validation is limited to a number of target species, most of which are primary NRT or OL level-2 products of the mission, with focus on NOy components: O3, NO2, NO, N2O, HNO3, HNO4, H2CO, CO and CH4. Synergistic use will be made of column and profile data from MIPAS, GOMOS and SCIAMACHY. The ground network will deliver mean vertical column abundances for all target species with NDSC-type quality, and height profile information for some target gases as secondary products to the PI's home institute, where the correlative analyses with the ENVISAT-1 products will be done. Asynoptic mapping tools will support the validation efforts.

SOGE is an integrated system for observation of halogenated greenhouse gases in Europe. There are two objectives: (1) To develop a new cost-effective long-term European observation system for halocarbons. The results will be in support of the Kyoto and the Montreal protocols,in assessing the compliance of European regions with the protocol requirements. In particular the observation system will be set up to: - detect trends in the concentrations of greenhouse active and ozone-destroying halocarbons; - verify reported emissions and validate emission inventories; - develop observational capacity for all halocarbons included in the Kyoto protocol (PFC, SF6) for which this is presently not yet existing; - develop a strategy for a cost-effective long-term observation system for halocarbons in Europe. (2) To predict and assess impacts of the halocarbons on the climate and on the ozone layer. This implies extensive exploitation of existing data. The impact assessment will be aimed at providing guidance for development of the Kyoto protocol and to the further development of the Montreal protocol mendments, by: - modelling impacts of halocarbons on radiative forcing and their relative importance for climate change; - modelling impacts of emissions of CFCs and HCFCs on the ozone layer.

The main specific objectives of UFTIR are: (1) To revise and homogenise the analyses of available experimental data for providing consistent time series of distinct tropospheric and stratospheric abundances of the target gases using new inversion algorithms. A common strategy for retrieval and characterisation of the vertical distributions of the target gases from FTIR ground-based measurements will be established. (2) To provide quantitative trends and associated uncertainties for the target gases over about the last decade, as a function of latitude throughout Western Europe, focusing on the troposphere. (3) To integrate the data in model assessments of the evolutions of tropospheric abundances. The measured burden and changes of the tropospheric gases will be compared with 3D model simulations, in order to help developing the latter, assist in explaining potential causes for the observed changes and to assess the consistencies between the trends at the surface to the free troposphere and lowermost stratosphere, and the agreement with known evolutions of emissions. UFTIR will make the community prepared to deliver tropospheric data for validation and synergistic exploitation of new satellite experiments like ENVISAT.

Study aerosol properties (size and composition) in the infrared spectral region

The major goal of the process study between April 15 and May 15, 2003 is to obtain quantified information on reaction path-ways, products and net deposition of mercury during Arctic sunrise.

In situ measurements in the stratosphere shall be carried out by means of different balloon soundings. The main goal is the investigation of aerosols in the tropopause-region and in the stratosphere during wintertime. Because generation of aerosols strongly depends on water vapour content, also water vapour will be measured.

The Italian Space Agency (ASI), in cooperation with CNR, would like to develop a balloon launch site at Ny-Ålesund. The polar stratospheric air circulation pattern can make it possible to perform Long Duration Balloon (LDB) Flights. The balloons would circumnavigate the northern Polar Regions collecting data in astrophysics, aeronomy, as well as other atmospheric, cosmic and biological sciences. The location on Svalbard is interesting for LDB flights because of : o easy access and transportation of equipment /material/personnel o well established infrastructures/support organization o the flight would occur over mostly unmanned areas o the recovery of the payload could easily happen on the land Currently two experiments are being built as LDB payloads in anticipation of launching from Ny-Ålesund in 2004 and 2005. These are astro-physics experiments to observe the galactic and cosmic microwave radiation. This facility would accommodate science teams from both Italy and around the world.

ASTAR, Arctic Study of Tropospheric Aerosol and Radiation is a a joint German (AWI Potsdam) - Japanese (NIPR Tokyo) campaign with participation from NASA LaRC Hampton, VA (USA). In addition to AWI, NIPR, and NASA LaRC the following institutions contributed to the project: Hokkaido University (Japan), Nagoya University (Japan), Norwegian Polar Institute Tromsoe/ Longyearbyen (Norway), NILU Kjeller (Norway), MISU Stockholm (Sweden), NOAA-CMDL Boulder, CO (USA) and Max Planck Institute for Aeronomy Katlenburg-Lindau (Germany). The campaign is based on simultaneous airborne measurements from the German research aircraft POLAR 4 and ground-based measurements in Ny-Ålesund. The main goals of the project are - to measure aerosol parameters of climate relevance, like extinction coefficient, absoprtion coefficients and phase function. - to create an Arctic Aerosol Data Set for climate impact investigation by using the regional climate model HIRHAM. - to carry out comparison measurements with the SAGE II (Stratospheric Aerosol and Gas Experiment) and the ground based Raman-Lidar.

In preparation to the launch of the SAGE III experiment in March 2001, NASA and the European Union performed the SOLVE / THESEO-2000 campaign, which had three components: (i) an aircraft campaign using the NASA DC-8 and ER-2 airplanes out of Kiruna/Sweden, (ii) launches of large stratospheric research balloons from Kiruna, (iii) validation excercises for the commissioning phase of SAGE III. The German Arctic research station Koldewey in Ny-Ålesund/Spitsbergen contributes to (i), (ii), and (iii) by performing measurements of stratospheric components like ozone, trace gases, aerosols (PSCs), temperature and winds. The measurement results were transmitted quasi online to the flight planning center in Kiruna, in order to allow a better directing of the air plane flights. In addition the Koldewey-Station has been designated a validation anchor site for the SAGE III validation. The activities are organized within a NASA accepted proposal of ground-based validation support by the NDSC Primary Station at Ny-Ålesund, Spitsbergen and by a SAGE III validation working group for Ny-Ålesund. The main observation periods are from December 1999 to March 2000.

In order to get detailed vertical ozone profiles above the range of standard electrochemical ozonesondes (typically 35 km), a radiosonde together with an optical ozonesensor is launchend with a special plastic foliage balloon. The balloon payload consists of a digital radiosonde (DFM 90) using GPS for altitude measurements and a two channel filter spectrometer (optical sensor) to measure the vertical ozone distribution up to more than 40 km altitude. The ozone profiles obtained by the optical sensors will be compared with ground-based microwave and lidar ozone observations as well as with the standard balloon-borne ozone measurements with electrochemical ozone sensors.

The aim of the project is to study the properties (radiative effects, composition) of aerosols using FTIR emission spectroscopy. To determine seasonal changes in aerosol properties the measurements will be carried out year round on a weekly schedule.

The German Aerospace Center (DLR) Bi-spectral Infrared Detection (BIRD) small satellite is a technology demonstrator of new infrared push-broom sensors dedicated to recognition and quantitative characterisation of thermal processes on the Earth surface. BIRD was successfully piggy-back launched on October 22, 2001 with an Indian Polar Satellite Launch Vehicle (PSLV-C3) into a circular sun-synchronous orbit with an altitude of 572 km and a North - South local equator crossing time at 10:30 h. Besides cameras working in the visible and near infrared spectral range there are two cameras working in the middle infrared (MIR, 3.4 – 4.2 µm) and in the thermal spectral range (TIR, 8.5 – 9.3 µm) respectively. The objective is to validate these two cameras in cooperation with the Koldewey-Station in Ny-Ålesund. Therefore meteorological and aerological data as well as radiation measuring data will be used.

The current scientific knowledge does not allow estimating accurately the surface radiative forcing caused by tropospheric aerosols and their influence on the evolution of the Earth climate. The radiative forcing depends on the optical properties of the aerosols at solar and thermal infrared wavelengths. These optical properties depend, in turn, on the chemical composition and size of the aerosols. Remote sensing with passive radiation sensors operating in the above-mentioned spectral ranges allows to measure the optical properties of the aerosols and to characterise their temporal variability. These data are needed for regional climate simulations of the Arctic, particularly for delineating the impact of the Arctic haze phenomenon. In this project, a synergetic effort will be made to obtain information about the radiative and microphysical properties of springtime arctic aerosols. Therefore, a polarisation-spectrometer for the solar spectral range, which is currently developed at the Free University of Berlin as a variant of the FUBISS spectrometer, will be operated from the surface in coincidence with the Fourier Transform InfraRed-spectrometer (FTIR) installed at Ny-Aalesund by the AWI. The former instrument measures the intensity and polarisation of the scattered solar radiation from the visible to the near-infrared. The latter measures the radiation emitted by the Atmosphere itself in the thermal infrared window region. Together, they thus provide a wealth of information about the aerosol optical properties at the interesting wavelengths (spectral optical depth, single-scattering albedo, and asymmetry factor of the phase function), which will allow inferring the aerosol microphysical properties. Complementary measurements of the aerosol microphysical properties will be provided by an aerosol volatility analyser, which is maintained by the University of Leeds and will also be brought to Ny-Aalesund. This instrument comprises a fast response scanning volatility system and an optical particle counter. From the thermal response of the aerosol number and the change in the size distribution conclusions can be inferred about the chemical composition and the state of mixing of aerosols as a function of size.

Aim of the project is to develop a cost-effective long-term European observation system for halocarbons and to predict and assess impacts of the halocarbons on the climate and on the ozone layer. Beside the routine observations within the NDSC it is planned to perform with FTIR (Fourier Transform Infrared Spectroscopy) absorption measurements of CFCs (e.g. SF6, CCl2F2, CHF2Cl) and related species on much more observation days.

The aim of the project is to perform solar and lunar absorption measurements of atmospheric trace gases for the valdation of the SCIAMACHY satellite. Besides the routine observations within the NDSC it is planned to perform more intense measurements, especially during the satellite overpasses.

Situated in the Arctic Ocean the planetary boundary layer over Ny Ålesund is dominated by marine aerosols. Hight and time variation of boundary layer aerosols are examined with the tropospheric lidar system in Ny Ålesund. To determine the aerosol and its optical properties more exactly information from more wavelenghts are necessary as the sun-photometer at the Koldewey Station can provide. First combined evaluation of photometer and LIDAR data during the ASTAR-campaign in spring 2000 demonstrated feasibility and advantages of this method for the free troposphere. Furthermore this method is to be applied on boundary layer aerosol to research also its optical properties.