Time series of average annual temperature at sea surface and bottom
For this sub-challenge not enough data was available to complete it. The data Sea Surface Temperature is widely spread and freely available, however the data on Sea Bottom Temperature is hard to find. No clashes were found in the data found, the datasets combined from different sources gave the same results. For this sub-challenge we feel major gaps are present for bottom temperatures, for surface temperatures the data is quite spread-out both spatially and temporally.
Because this sub-challenge is quite broad and not clearly defined, in the results multiple options are given for the viewer to observe.
For an interactive map with data on water temperature please go to http://www.emodnet-physics.eu/map/ and click on “water temperature”.
Figure 1: Median average Sea Surface Temperature anomaly for the Northern Hemisphere, datasource: UK Met Office).
Figure 2: Sea Surface Temperature anomaly, datasource: NOAA.
Figure 3: Sea Surface and Bottom Temperature in 2012, datasource: Rabe et al., 2015.
Figure 4: Time series of area-averaged SST anomalies [°C] for August of each year relative to the August mean for the period 1982-2010 for the Chukchi and Kara seas and eastern Baffin Bay. The dash-dotted black line shows the linear SST trend for the Chukchi Sea (the same warming trend as eastern Baffin Bay). Numbers in the legend correspond to linear trends (with 95% confidence intervals) in °C/year (source: Timmermans & Proshutinsky, 2015).
Figure 5: Cool in most of Canada's Arctic but the heat was on elsewhere in the circumpolar world: October 2014 to September 2015 average air temperatures across the Arctic compared to the 1981-2010 average and history of Arctic temperatures compared to the global average. (IMAGE COURTESY OF NOAA) (source : http://www.nunatsiaqonline.ca/stories/article/656742015_noaa_arctic_report_card_shows_increased_heat/)
Figure 6: A reconstruction of Arctic summer temperatures. The blue line shows estimates of Arctic temperatures over the last 2,000 years, based on proxy records from lake sediments, ice cores, and tree rings. The green line shows the long-term cooling trend. The red line shows the recent warming based on actual observations. From Kaufman et al. (2009), modified by UCAR (source: AMAP 2012)
Figure 7: The 2007–2014 mooring record: (a) near-bottom water (blue) and midwater (red) salinity and (b) temperature. The data were smoothed using a 2?day running mean in order to remove high-frequency variability. Areal-mean SSTs [Reynolds et al., 2002] are included for comparison (green). Red dots in the first half of the record indicate midwater values from CTD profiles. Note that the September 2013 to September 2014 deployment is ~146?km north of the previous location; the black dashed line marks the transition time. Gray shades in Figures 1a and 1b mark the time period expanded in Figure 3e. Black bars at the top of Figure 1a indicate ice cover [Cavalieri et al., 1996]. (c) The white star marks the mooring location. Letters mark adjacent shelf seas: Barents (BS), Kara (KS), East Siberian (ESS), and Chukchi (CS) Seas. Light blue shading indicates regions <300?m [Jakobsson et al., 2008]. (d) The white box outlines an expanded view, showing previous (big star) and shifted mooring location (little star), and 10, 30, 50, and 200?m isobaths (source: Janout et al. 2016)
For this sub-challenge, the following sources were used:
- Timmermans, M.L. & a. Proshutinsky, 2015. Sea surface Temperature. In: Arctic Report Card: Update for 2015.
- Arctic Report Card: Update for 2015.
- AMAP, 2012. Arctic Climate Issues 2011: Changes in Arctic Snow, Water, Ice and Permafrost. SWIPA 2011, Overview report. https://www.innovation.ca/sites/default/files/Rome2013/files/SWIPA%20Overview%20Report%202011.pdf
- Janout, M., J. Hölemann, B. Juhls, T. Krumpen, B. Rabe, D. Bauch, C. Wegner, H. Kassens & L. Timokhov, 2016. Episodic warming of near-bottom waters under the Arctic sea ice on the central Laptev Sea shelf. Geophysical Research Letters 43(1): 264-272. http://onlinelibrary.wiley.com/doi/10.1002/2015GL066565/full
- Rabe, Benjamin; Kikuchi, Takashi; Wisotzki, Andreas (2015): Physical oceanography from 86 XCTD stations during POLARSTERN cruise ARK-XXVII/3 (IceArc). doi:10.1594/PANGAEA.849735 https://doi.pangaea.de/10.1594/PANGAEA.849735