Publications

Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter

Nishii, K.; Taguchi, B.; Nakamura, H.; Orsolini, Yvan Joseph Georges Emile G.

Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter

Nishii, K.; Taguchi, B.; Nakamura, H.; Orsolini, Yvan

Large upper tropospheric ozone enhancements above midlatitude North America during summer: In situ evidence from the IONS and MOZAIC ozone measurement network.

Cooper, O.R.; Stohl, A.; Trainer, M.; Thompson, A.M.; Witte, J.C.; Oltmans, S.J.; Morris, G.; Pickering, K.E.; Crawford, J.H.; Chen, G.; Cohen, R.C.; Bertram, T.H.; Wooldridge, P.; Perring, A.; Brune, W.H.; Merrill, J.; Moody, J.L.; Tarasick, D.; Nédélec, P.; Forbes, G.; Newchurch, M.J.; Schmidlin, F.J.; Johnson, B.J.; Turquety, S.; Baughcum, S.L.; Ren, X.; Fehsenfeld, F.C.; Meagher, J.F.; Spichtinger, N.; Brown, C.C.; McKeen, S.A.; McDermid, I.S.,, Leblanc, T.

Large seasonal and interannual variations of biogenic sulfur compounds in the Arctic atmosphere (Svalbard; 78.9° N, 11.9° E)

Jang, Sehyun; Park, Ki-Tae; Lee, Kitack; Yoon, Young Jun; Kim, Kitae; Chung, Hyun Young; Jang, Eunho; Becagli, Silvia; Lee, Bang Young; Traversi, Rita; Eleftheriadis, Konstantinos; Krejci, Radovan; Hermansen, Ove

Seasonal to interannual variations in the concentrations of sulfur aerosols (< 2.5 µm in diameter; non sea-salt sulfate: NSS-SO2−4; anthropogenic sulfate: Anth-SO2−4; biogenic sulfate: Bio-SO2−4; methanesulfonic acid: MSA) in the Arctic atmosphere were investigated using measurements of the chemical composition of aerosols collected at Ny-Ålesund, Svalbard (78.9∘ N, 11.9∘ E) from 2015 to 2019. In all measurement years the concentration of NSS-SO2−4 was highest during the pre-bloom period and rapidly decreased towards summer. During the pre-bloom period we found a strong correlation between NSS-SO2−4 (sum of Anth-SO2−4 and Bio-SO2−4) and Anth-SO2−4. This was because more than 50 % of the NSS-SO2−4 measured during this period was Anth-SO2−4, which originated in northern Europe and was subsequently transported to the Arctic in Arctic haze. Unexpected increases in the concentration of Bio-SO2−4 aerosols (an oxidation product of dimethylsulfide: DMS) were occasionally found during the pre-bloom period. These probably originated in regions to the south (the North Atlantic Ocean and the Norwegian Sea) rather than in ocean areas in the proximity of Ny-Ålesund. Another oxidation product of DMS is MSA, and the ratio of MSA to Bio-SO2−4 is extensively used to estimate the total amount of DMS-derived aerosol particles in remote marine environments. The concentration of MSA during the pre-bloom period remained low, primarily because of the greater loss of MSA relative to Bio-SO2−4 and the suppression of condensation of gaseous MSA onto particles already present in air masses being transported northwards from distant ocean source regions (existing particles). In addition, the low light intensity during the pre-bloom period resulted in a low concentration of photochemically activated oxidant species including OH radicals and BrO; these conditions favored the oxidation pathway of DMS to Bio-SO2−4 rather than to MSA, which acted to lower the MSA concentration at Ny-Ålesund. The concentration of MSA peaked in May or June and was positively correlated with phytoplankton biomass in the Greenland and Barents seas around Svalbard. As a result, the mean ratio of MSA to the DMS-derived aerosols was low (0.09 ± 0.07) in the pre-bloom period but high (0.32 ± 0.15) in the bloom and post-bloom periods. There was large interannual variability in the ratio of MSA to Bio-SO2−4 (i.e., 0.24 ± 0.11 in 2017, 0.40 ± 0.14 in 2018, and 0.36 ± 0.14 in 2019) during the bloom and post-bloom periods. This was probably associated with changes in the chemical properties of existing particles, biological activities surrounding the observation site, and air mass transport patterns. Our results indicate that MSA is not a conservative tracer for predicting DMS-derived particles, and the contribution of MSA to the growth of newly formed particles may be much larger during the bloom and post-bloom periods than during the pre-bloom period.

Large emissions of perfluorocarbons in East Asia deduced from continuous atmospheric measurements.

Saito, S.; Yokouchi, Y.; Stohl, A.; Taguchi, S.; Mukai, H.

Large Circulation Patterns Strongly Modulate Long-Term Variability of Arctic Black Carbon Levels and Areas of Origin

Stathopoulos, Vasileios; Evangeliou, Nikolaos; Stohl, Andreas; Vratolis, Stergios; Matsoukas, Christos; Eleftheriadis, Konstantinos

Black Carbon (BC) aerosol is a major climate forcer in the Arctic. Here, we present 15 years (2001–2015) of surface observations of the aerosol absorption coefficient babs (corresponding to Equivalent BC), obtained at the Zeppelin Observatory, Ny Ålesund, Svalbard, coupled with backward transport modeling with Flexpart in order to calculate the Potential Source Contribution Function (PSCF) for BC. The observed long-term variability superimposed on a strong annual cycle is studied as a function of large-scale circulation patterns represented by monthly index values for the North Atlantic Oscillation (NAO) and the Scandinavian pattern (SCAN). We find a 35% increase of babs values at Zeppelin during the SCAN+ phase in the winter half-year compared to the SCAN+ phase but no significant difference in babs values between the NAO index phases. Both NAO and SCAN induce significant regional variability on the areas of origin of babs, mainly Siberia, Europe, and North America.

American Geophysical Union (AGU)

Langtransporterte luftforurensninger. Powerpoint presentasjon. NILU F

Schlabach, M.

Langtransport von persistenten Umweltgiften in die Arktis.

Kallenborn, R.; Burkow, I. C.

Langt nede i isen finnes det luft som er flere hundre tusen år gammel

Eckhardt, Sabine; Steen-Larsen, Hans Christian (interview subjects); Aas, Vilde Aardahl (journalist)

Land-Ocean Interactions in the Coastal Zone: past, present & future.

Ramesh, R.; Chen, Z.; Cummins, V.; Day, J.; D'Elia, C.; Dennison, B.; Forbes, D.L.; Glaeser, B.; Glaser, M.; Glavovic, B.; Kremer, H.; Lange, M.; Larsen, J.N.; Tissier, M.L.; Newton, A.; Pelling, M.; Purvaja, R.; Wolanski, E.

Land use regression modelling for air quality exposure: A step in the wrong direction.

Denby, B.R.

Land surface temperature validation for WACMOS-ET. Reference input data set validation report. NILU report

Schneider, P.; Prata, F.; Martins, J.; Pires, A.; Trigo, I.; Jimenez, C.; Goettsche, F.; Hook, S. J.

The Land Surface Temperature (LST) products generated specifically for theWAter Cycle Observation Multi-mission Strategy - EvapoTranspiration (WACMOS-ET)project, funded by the European Space Agency (ESA), are evaluated with respect to their overall quality. LST products derived from observations acquired by the Advanced Along-Track Scanning Radiometer (AATSR), the Multi-Functional Transport Satellite (MTSAT), and the Geostationary Operational Environmental Satellite (GOES) were studied here. Following previously established best-practices on LST validation, the evaluation includes both a qualitative component addressing general issues with the data, as well as a quantitative component, which compares the LST products directly against a reference dataset. For the latter satellite LST is compared against both ground-based in situ datasets acting as a source of absolute reference data and against independent satellite-based LST products from other sensors to provide a spatially exhaustive relative comparison.