Projects/Activities

In december 2001 the SAGE III experiment was successfully launched. The NASA science team of the SAGE III experiment has announced the Koldewey-Station in Ny-Aalesund as "anchor site" for validation, especially for such parameters as optical depth, aerosol extinction profiles and ozone profiles. Because of time coincidence NASA apprechiates support for the prospected validation activities for ENVISAT. This should be also considered as contribution to the NASA accepted project "Ground based Validation of SAGE III by the NDSC Primary Station at Ny-Ålesund, Spitsbergen" for SOLVE-2.

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.

Study of the energy exchange between atmosphere, sea ice and ocean during freezing and melting conditions; within that, measurements of solar radiation (visible and UV) and optical properties, snow and sea ice characteristics, vertical heat and salt fluxes, oceanographic parameters.

The general objective of the project is to increase the understanding of the Mercury Depletion Events occuring at Arctic sunrise and to quantify the input of mercury to polar ecosystems during this events.

To distinguish between atmospheric and marine transport of contaminants to northen latitudes by comparison inventories of lake and fjordic sediments.

Monitoring solar wind-magnetosphere-ionosphere coupling processes from the aurora.

The general objective of the proposed project is to increase the understanding of the Mercury Depetion Events occoring in the Arctic sunrise and quntify the input of mercury to polar ecosystems during this events.

Study of the energy exchange between atmosphere and ice sheets by means of measurment of solar radiation

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.

Projects at Zackenberg Station Relevance: Climate Change Project title: Duration: Start year: 1995 End year: Continuing Responsible institution: Relevance: Climate Change Changes in UV radiation and its effects

The main objective is to establish a scientific basis for the detection of the earliest signs of ozone recovery due to Montreal protocol and its amendments. To achieve this we will select the best long-term ozone and meteorological data sets available (by ECMWF and NCEP). Ozone data will be studied by using advanced multiple regression methods developed in this project. Meteorological data would allow to determine the dynamical changes and trends and assess their role in re-distribution of stratospheric ozone in recent decades and in order to force the Chemical Transport Models to assess the relative roles of chemistry and transport in ozone changes. Finally, the synthesis of the key objectives will improve the attribution of observed ozone changes to anthropogenic influences and to the variations in a natural atmosphere.

A dedicated study into the formation of new particles, PARFORCE (New particle formation and fate in the coastal environment), was conducted over a period from 1998-1999 at the Mace Head Atmospheric Research Station on the western coast of Ireland. Continuous measurements of new particle formation were taken over the two-year period while two intensive field campaigns were also conducted, one in September 1998, and the other in June 1999. New particle events were observed on »90% of days and occurred throughout the year and in all air mass types. These events lasted for, typically, a few hours, with some events lasting more than 8 hours, and occurred during daylight hours coinciding with the occurrence of low tide and exposed shorelines. During these events, peak aerosol concentrations often exceeded 10 6 cm -3 under clean air conditions while measured formation rates of detectable particle sizes (i.e. d > 3nm) were of the order of 10 4 -10 5 cm -3 s -1 . Nucleation rates of new particles were estimated to be, at least, of the order of 10 5 -10 6 cm -3 s -1 and occurred for sulphuric acid concentrations above 2 x 10 6 molecules cm -3 ; however, no correlation existed between peak sulphuric acid concentrations, low tide occurrence or nucleation events. Ternary nucleation theory of the H2SO4-H2O-NH3 system predicts that nucleation rates far in excess of 10 6 cm -3 s -1 can readily occur for the given sulphuric acid concentrations; however, aerosol growth modelling studies predict that there is insufficient sulphuric acid to grow new particles (of »1 nm in size) into detectable sizes of 3 nm. Hygroscopic growth factor analysis of recently-formed 8 nm particles illustrate that these particles must comprise some species significantly less soluble than sulphate aerosol. The nucleation-mode hygroscopic data, combined with the lack of detectable VOC emissions from coastal biota, the strong emission of biogenic halocarbon species, and the finger-printing of iodine in recently-formed (7 nm) particles suggest that the most likely species resulting in the growth of new particles to detectable sizes is an iodine oxide as suggested by previous laboratory experiments. It remains an open question whether nucleation is driven by self nucleation of iodine species, a halocarbon derivative, or whether first, stable clusters are formed through ternary nucleation of sulphuric acid, ammonia and water vapour, followed by condensation growth into detectable sizes by condensation of iodine species. Airborne measurements confirm that nucleation occurs all along the coastline and that the coastal biogenic aerosol plume can extend many 100s of km away from the source. During the evolution of the coastal plume, particle growth is observed up to radiatively-active sizes of 100 nm. Modelling studies of the yield of cloud-condensation nuclei suggest that the cloud condensation nuclei population can increase by »100%. Given that the production of new particles from coastal biogenic sources occurs at least all along the western coast of Europe, and possibly many other coastlines, it is suggested that coastal aerosols contribute significantly to the natural background aerosol population.

The International Panel on Climate Change (IPCC) has very recently revised the prediction of global average temperature increase during the next century from 1.0-3.5 to 1.4-5.8 K. The increase in the upper limit of the prediction is largely due to the role of aerosols in the climate of the Earth: it is believed that reduction of pollution will result in reduced direct and indirect (via clouds) scattering of sunlight back to the space. However, as can be seen from the large uncertainty of the estimated temperature increase, not enough is known about the role of natural and anthropogenic aerosols in climate processes. This is also reflected in the Key Action 2, under the RTD priority 2.1.1, calling for ”… quantification and prediction of … concentration of … aerosols, in particular the fine fraction of particles and their precursors”. The concentration of aerosols is controlled by their sources and sinks, and thus the prediction of particle concentration requires the quantification of aerosol source terms. The main objective of QUEST is to quantify the number of new secondary aerosol particles formed through homogeneous nucleation in the European boundary layer, and the relative contributions of natural and anthropogenic sources. The role of homogeneous nucleation in the formation of new atmospheric particles was realized in the 1990s, and considerable effort has been devoted to studies of aerosol formation in various parts of the Globe. The longest continuous data series of nucleation events has been obtained at a forest field station in Finland, where aerosol size distributions between 3 and 150 nm in diameter have been recorded in 10 minute intervals since the beginning of 1996 [1]. Nucleation events occur in this rather clean Boreal area roughly 50-60 times per year, the highest event frequency taking place in the spring months (March-May). The concentration of new particles per cc of air formed during one event varies between roughly 100-10 000. Taking the average number to be one thousand, and assuming that the nucleation takes place in a well mixed boundary layer having a height of 1000 m, it can be estimated that the aerosol source term in the Boreal forest area is on the order of 51013 m-2 per year. This is on the same order as the global aerosol yield estimated from primary emissions [2]. The number given here is very crude as we can at present only guess the vertical extent of the nucleation zone; however, it clearly shows that homogeneous nucleation events influence atmospheric particle concentrations at least at regional scales, and possibly also globally. Many features of the Boreal nucleation events have been revealed thus far. Necessary (but not sufficient) conditions include sunny weather, vertical mixing of air in the morning (prior to the detection of the event) [1], and a treshold value of a quantity that depends on radiation intensity (vapor source) and pre-existing aerosol size distribution (vapor sink) [3]. The springtime events always seem to take place in Polar or Arctic air masses [4], but so far it is unclear whether the meteorology is similar during other seasons. Aerosol flux measurements [5] indicate that the particles are formed aloft, but the vertical extent of the nucleation layer is unknown. However, there is clear evidence from simultaneous measurements at various locations, that the horizontal extent of the areas in which the nucleation takes place can be hundreds and in some cases even thousands of kilometers [1]. No direct correlation of nucleation events with SO2 concentrations has been found; however the product of SO2 concentration, ammonia concentration, and calculated OH concentration correlates with the events (personal communication). These results hint that the recently suggested ternary sulfuric acid-ammonia-water nucleation mechanism of small clusters, followed by the growth of the clusters due to condensation of other (possibly organic) vapors [6], may be operational in the Boreal forest area. Furthermore, there is experimental evidence that nucleation event particles in the 4-5 nm range are soluble in butanol (working fluid of condensation particle counters), which indicates organic composition. However, the confirmation of the ternary nucleation hypothesis requires simultaneous measurements of sulfuric acid vapor and ammonia, and further studies of the composition of the nucleated particles. Furthermore, to facilitate large-scale modelling studies, the vertical extent of the nucleation events, as well as the meteorological conditions during non-springtime events have to be investigated. Measurements of nucleation events at a more Central European location indicate that SO2 levels increase during the majority of nucleation events [7]. It can be hypothesized that a part of observed nucleation events (minority in Central Europe, majority in the Boreal area) are ”natural” and a part are affected (or even caused) by pollution (majority in Central Europe, minority in the Boreal area). The confirmation of this hypothesis and implementation of the pollution type nucleation mechanism into a large-scale model requires carefully designed measurements from a location which is preferably Southern European as there is very little available nucleation data from this area. One of the few observations of new particles in Southern Europe [8] is from the Italian site where we plan to study the frequency, meteorology, vertical extent, and chemical precursors of nucleation events. Another type of nucleation events has been observed all along the western coast of Europe and have been studied more particularly at the west coast of Ireland [9]. These events, which have a duration of the order of 4 hours and up to 8 hours, occur almost daily around low tide and under conditions of solar radiation, indicating photochemical source. Incredibly, the peak new particle concentrations often exceed 106 cm-3, making this the strongest natural source region of atmospheric particles. The exact chemical mechanisms leading to the production of coastal particles still remains an open question. As in other environments, there appears to be sufficient sulphuric acid vapour to participate in ternary nucleation with ammonia and water, however, there is insufficient sulphuric acid to grow these particles to detectable sizes [9]. The most probable chemical species involved in the production or growth of these particles is Iodine, or an Iodine Oxide, produced photochemically from biogenic halocarbon emissions [9]. The production of particles from the photolysis of CH2I2 in the presence of ozone has been confirmed by recent smog chamber experiments [10]. While the concentration of new particles in this environment is extraordinarily high, its impact on background particle and CCN contribution remains unclear and needs to be quantified. A limited single study [11] has shown that the coastal aerosol plume is detectable up to several hunderds of km downwind and that the new coastal particles readily grow into CCN sizes (larger than 100 nm). An intensive campaign at the coast of Ireland will quantify the flux of both biogenic halocarbon precursor gases and the yield of new, and radiatively-active particles in the European coastal boundary layer. The objective of QUEST is to determine the source strength of new particle formation in the three above mentioned cases. The specific objectives are: 1) To fill in gaps that exist in the understanding of chemical and physical pathways leading to homogeneous nucleation of new aerosol particles; 2) To understand the meteorological conditions required for the events to take place and to be able to predict the horizontal and vertical extent of the events; 3) To implement parametrized representations of the nucleation mechanisms, based on the information from 1) and 2), to an European scale model in order to determine the source strength of homogeneous nucleation of aerosol particles in the European boundary layer.

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.