Several important ice-free areas (e.g., Seymour Island, Cape Lamb on Vega Island, Terrapin Hill) are located in the Eastern Antarctic Peninsula region. The largest of these ice-free areas can be found on the Ulu Peninsula, James Ross Island, where this study was undertaken. The Ulu Peninsula covers an area of 312 km 2 , and has been found to be an important active High Latitude Dust source. In this study, aerosol concentrations and local wind properties are described together with their linkages and typical synoptic situations. The highest aerosol concentrations of 57 µg m −3 for PM 10 were detected during high wind speed events that exceeded 10 m s −1 , which is also a threshold level for activating local mineral material sources. Surface deposition of dust particles can have significant environmental impacts such as changes in properties of atmosphere or enhanced snow melting.

Studies assessing air temperature variations and their dependence on altitude from the eastern side of the Antarctic Peninsula are sparse. In this paper, we analyse air temperature and near‐surface lapse rates from the Ulu Peninsula (James Ross Island, Antarctic Peninsula). The temperature data were acquired from nine sites both in ice‐free areas and glaciers of the Ulu Peninsula in 2013–2016. The most important factors influencing air temperature differences were sea‐ice conditions, topography and ground surface properties. During the study period, air temperature decreased with height with the mean lapse rate of 0.40 °C 100 m−1 for the ice‐free sites (10–375 m a.s.l.) and 0.43 °C 100 m−1 for the glaciated sites (268–539 m a.s.l.). However, the values were lower in winter (ice‐free: 0.02 °C 100 m−1 and glacier: 0.31 °C 100 m−1) than in summer (ice‐free: 0.62 °C 100 m−1 and glacier: 0.51 °C 100 m−1) for both categories. The air layer between 10 and 56 m a.s.l. in the ice‐free area revealed an almost year‐round air temperature inversion resulting in a mean lapse rate of −0.79 °C 100 m−1 and an air temperature inversion frequency reaching up to 43%. The temperature inversion frequency was 10% lower for the lowest air layer for the glacier category, which was between 268 and 356 m a.s.l. The land surface air temperature was the highest when the wind was from the northwest and lowest when it was from the south–southwest. The near‐surface lapse rate–wind direction relationship was the most pronounced for the air layer between 10 and 56 m a.s.l. with the lowest mean lapse rate for west–southwest wind (−2.83 °C 100 m−1) and the highest for east–northeast wind (0.41 °C 100 m−1).

Abstract:A two-year-long data set of air temperature from four different altitudes above Petuniabukta, central Spitsbergen, was analysed in order to assess the near-surface temperature lapse rates and the relative frequency of air temperature inversion occurrence. From August 2013 to July 2015, air temperatures at adjacent altitudes in Petuniabukta were strongly correlated. The near-surface lapse rates in all three layers differed significantly both from the average lapse rate in the international standard atmosphere (0.65°C 100 m -1 ) and the lapse rate calculated by linear regression. A pronounced annual cycle was detected in the lowermost air layer (from 23 to 136 m a.s.l.) with a variable near-surface lapse rate in the winter months, while an annual cycle was not apparent in the air layers above 136 m a.s.l. The lowermost layer was also characterized by a notable daily cycle in near-surface lapse rate in spring and autumn. Air temperature inversions occurred in up to 80% of the study period in the air layer below 136 m a.s.l., with the relative frequency being much lower in the other two air layers. The air temperature inversions lasted as long as 139 hours. A case study revealed that one of the strongest air temperature inversions was connected to an area of lower pressure gradients at the 850-hPa pressure level.

Despite the key role of the surface energy budget in the global climate system, such investigations are rare in Antarctica. In this study, the surface energy budget measurements from the largest ice-free area on northern James Ross Island, in Antarctica, were obtained. The components of net radiation were measured by a net radiometer, while sensible heat flux was measured by a sonic anemometer and ground heat flux by heat flux plates. The surface energy budget was compared with the rest of the Antarctic Peninsula Region and selected places in the Arctic and the impact of surface energy budget components on the ground thermal regime was examined. Mean net radiation on James Ross Island during January–March 2018 reached 102.5 W m−2. The main surface energy budget component was the latent heat flux, while the sensible heat flux values were only 0.4 W m−2 lower. Mean ground heat flux was only 0.4 Wm-2, however, it was negative in 47% of January–March 2018, while it was positive in the rest of the time. The ground thermal regime was affected by surface energy budget components to a depth of 50 cm. The strongest relationship was found between ground heat flux and ground surface temperature. Further analysis confirmed that active layer refroze after a sequence of three days with negative ground heat flux even in summer months. Daily mean net radiation and ground heat flux were significantly reduced when cloud amount increased, while the influence of snow cover on ground surface temperature was negligible.

The influence of synoptic‐scale circulation on air temperature variation in the ice‐free and glaciated areas on the eastern side of the Antarctic Peninsula (AP) has been analysed. For this purpose, a new classification of atmospheric circulation with 15 synoptic patterns in the AP region was developed using the self‐organizing maps technique. The synoptic patterns were compared with air temperature observations from coastal and glacial sites on James Ross Island, northeastern AP, in the period 2005–2015. The most frequent synoptic pattern with a frequency of 13.7% was dominated by a low‐pressure centre in the northwestern Bellingshausen Sea, which extended over the AP to the Weddell Sea. On the other hand, the largest inter‐annual variability was observed for a synoptic pattern with a low‐pressure centre in the southern Bellingshausen Sea. This synoptic pattern also had the highest air temperature anomalies at both investigated sites year‐round. Air temperature anomalies at the lower lying site (Mendel station) were the lowest during a high‐pressure ridge dominating the AP region due to a combination of local and synoptic‐scale processes. At Davies Dome, the glacial site, southerly barrier winds advecting cold air from the ice‐covered Weddell Sea during a strong low‐pressure system in the Weddell Sea ensured the coldest air temperature anomalies.