Influence of large-scale atmospheric variability patterns and sea ice on air temperature on James Ross Island, Antarctica
| Autoři | |
|---|---|
| Rok publikování | 2018 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | In the recent decade, the Antarctic Peninsula Region has been experiencing a period of cooling, which was attributed to increased cyclonic conditions resulting in higher sea ice concentration around the northern AP (Turner et al., 2016). Therehas also been a discussion about the influence of El Nino – Southern Oscillation (ENSO) and Southern Annular Mode (SAM) on air temperature in the Antarctic Peninsula Region which should also depend on the interaction between ENSO and SAM (e.g., Clem et al., 2016). In this study, we have analysed the relationship between air temperature from the Ulu Peninsula (James Ross Island), ENSO, SAM and sea ice in the vicinity of James Ross Island. Air temperature data were measured at 2 m height above ice-free surface of a marine terrace close to Johann Gregor Mendel Czech Antarctic Station during the period 2005–2016. The ENSO phenomenon was represented by Multivariate ENSO Index (MEI; NOAA ESRL PSD, 2018), while sea ice influence was characterised as a sea ice fraction in the gridpoint closest to the Johann Gregor Mendel Station in the MERRA-2 Reanalysis (NASA, 2018). All the data including SAM Index (UCAR, 2018) were analysed as monthly means. There was found a statistically significant negative relationship between air temperature and sea ice (correlation coefficient r = -0.88); however, due to common annual cycle in air temperature and sea ice data, the relationship was only moderate (r = -0.59) when the differences from the monthly mean of the whole study period were utilised. The relationship was strongest in winter and weakest in summer. The influence of SAM on air temperature was only moderate for the whole study period (r = 0.35), even though also statistically significant, and similarly to sea ice, its influence was largest in winter (r = 0.56). Interestingly, there was also a statistically significant relationship between sea ice and SAM in winter (r = -0.52). Finally, no relationship was ascertained between air temperature on the Ulu Peninsula and ENSO. |
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