Surface radiation climatology for Ny-Ålesund, Svalbard (78.9° N), basic observations for trend detection

Abstract

At Ny-Ålesund (78.9°N), Svalbard, surface radiation measurements of up-and downward short-and longwave radiation are operated since August 1992 in the frame of the Baseline Surface Radiation Network (BSRN), complemented with surface and upper air meteorology since August 1993. The long-term observations are the base for a climatological presentation of the surface radiation data. Over the 21-year observation period, ongoing changes in the Arctic climate system are reflected. Particularly, the observations indicate a strong seasonality of surface warming and related changes in different radiation parameters. The annual mean temperature at Ny-Ålesund has risen by +1.3±0.7 K per decade, with a maximum seasonal increase during the winter months of +3.1± 2.6 K per decade. At the same time, winter is also the season with the largest long-term changes in radiation, featuring an increase of +15.6±11.6 Wm −2 per decade in the downward longwave radiation. Furthermore, changes in the reflected solar radiation during the months of snow melt indicate an earlier onset of the warm season by about 1 week compared to the beginning of the observations. The supplementary dataset of Ny-Ålesund surface radiation measurements (available at http://dx.doi.org/10.1594/PANGAEA.150000) provides a valuable data source for the validation of satellite instruments and climate models.

Arctic warming, moisture increase and circulation changes observed in the Ny-Ålesund homogenized radiosonde record

“…On the background of increasing surface downward longwave radiation in Ny-Ålesund (Maturilli et al 2015), the contribution of humidity inversions to the total integrated water vapour (IWV) has been analysed for the period 1993 to 2014. It turns out that the contribution by humidity inversions remains stable over the years, while for the winter months an increase is found in the total IWV, identified to be caused by a moisture increase in the large-scale background humidity profile.…”

“…At Ny-Ålesund, the Alfred Wegener Institute for Polar and Marine Research operates an atmospheric observatory since more than two decades, comprising measurements from the surface to the upper atmosphere. The Ny-Ålesund surface observations reflect the recent Arctic warming, with an annual mean temperature increase of +1.3 ± 0.7 K per decade in the period 1994 to 2013 (Maturilli et al 2015). The largest part of this observed warming attributes to the dark winter season, with the December-January-February mean temperature increasing by +3.1 ± 2.4 K per decade (Maturilli et al 2015).…”

“…Over the last two decades in Ny-Ålesund, surface warming and changes in the surface radiation balance components have been detected (Maturilli et al 2013(Maturilli et al , 2015. Here, we analyse related changes in the upper-air profiles measured by radiosondes in the period 1993 to 2014.…”

“…The Ny-Ålesund surface observations reflect the recent Arctic warming, with an annual mean temperature increase of +1.3 ± 0.7 K per decade in the period 1994 to 2013 (Maturilli et al 2015). The largest part of this observed warming attributes to the dark winter season, with the December-January-February mean temperature increasing by +3.1 ± 2.4 K per decade (Maturilli et al 2015). For the same period, the winter LW surface radiation budget is found to increase considerably, with +11.6 ± 10.9 Wm −2 for the upward and +15.6 ± 11.6 Wm −2 for the downward LW surface radiation (Maturilli et al 2015).…”

“…The largest part of this observed warming attributes to the dark winter season, with the December-January-February mean temperature increasing by +3.1 ± 2.4 K per decade (Maturilli et al 2015). For the same period, the winter LW surface radiation budget is found to increase considerably, with +11.6 ± 10.9 Wm −2 for the upward and +15.6 ± 11.6 Wm −2 for the downward LW surface radiation (Maturilli et al 2015). While the upward LW radiation increase is generally linked to the surface temperature increase, the pronounced increase in the downward radiation indicates a radiative contribution from the atmospheric column.…”