Soil samples from the summit of Coulman Island in northern Victoria Land, continental Antarctica (lat. 73°28'S, 169°45'E), were cultured and after nine weeks they have yielded sterile shoots of a funarialean moss. Its identity is discussed and, on the basis of the leaf shape, it is determined, with some reservation, as Entosthodon subnudus (Taylor) Fife, a species native to the Australia-New Zealand biogeographical province. This example provides further evidence of the existence of soil propagule banks, sometimes containing taxa not known in the flora of the Antarctic biome. Because of the severity of the polar climate and permanently frigid dry desert conditions, many such propagules may never succeed in growing in situ. The occurrence of E. subnudus represents the highest elevation (2930 m) at which a viable plant propagule has been recorded in Antarctica.
As the earth's third pole, Qinghai-Tibet Plateau belongs to one of the most sensitive regions to climate change in the world. Based on the observed and the simulated daily precipitation from the Coupled Model Intercomparison Project Phase 5 (CMIP5), we evaluated the simulation performance of daily precipitation from selected CMIP5 models from 1975 to 2005 over the Qinghai-Tibet Plateau. We found that daily precipitation exhibited obvious long-range correlation characteristics using the detrended fluctuation analysis method. The scaling exponents of daily precipitation in summer and autumn are significantly larger than those in spring and winter. MIROC4H with the best performance can reproduce long-range correlation characteristic of daily precipitation series probably because of the higher resolution, which can capture small scale cloud convections. Besides there are seasonal differences in the simulation results among different regions of the Qinghai-Tibet Plateau, simulation effects of all climate models in summer and winter are better than those in spring and autumn. The performance of MIROC4H model works the best in spring. Overall, the scaling exponents of daily precipitation from BCC-CSM1-1-M, CMCC-CM and MIROC4H are close to the observations. CCSM4 and MIROC4H climate models could reproduce the internal dynamics characteristic of daily precipitation in autumn. But for winter, all climate models have exaggerated the scaling value in southeastern Qinghai-Tibet Plateau compared with the observed values.
Cloud fractions were observed during research cruises onboard the research vessel (R/V) Shirase between Japan and Antarctica using a whole-sky camera and a ceilometer. The cruises, Japanese Antarctic Research Expeditions (JARE) 55 and 56, took place from November 2013 to April 2014 and from November 2014 to April 2015, respectively. Cloud fractions were estimated from the whole-sky camera based on the sky brightness and spectral characteristics, and the ceilometer recorded the cloud occurrence frequency. According to the comparison of daily-averaged cloud fractions from the whole-sky camera with the ceilometer observations over the open ocean between Japan and Antarctica, the correlation coefficients were 0.87 and 0.93 for JARE 55 and 56, respectively. Overall, the results from both observation methods were consistent over the open ocean. Nevertheless, it was necessary to take surface conditions into consideration, particularly for the estimated cloud fractions from the whole-sky camera, because the contrast in brightness and spectral properties between cloudy and clear skies was lower over the sea ice region, owing to the higher surface albedo. Hence, the classification parameter was expressed as a function of sun elevation over the sea ice region in this study. This parameter was determined from part of the data over the sea ice region during JARE 55 and then applied to JARE 56 as well as to the remaining data from JARE 55. As a result, the daily-averaged cloud fractions over the sea ice region were approximately 84 % and 57 % from JARE 55 and 56, respectively. The daily-averaged cloud fractions estimated from the whole-sky camera were also consistent with the ceilometer observations, where the correlation coefficients with the sea ice region were 0.93 and 0.96 for JARE 55 and 56, respectively.
Warm events, periods when rising surface air temperatures can trigger surface melt, have been recorded during the austral summer at Syowa station on the East Antarctic coast. This study identifies air masses responsible for summer warm events at Syowa. Air masses arriving at Syowa are classified into marine and glacial sources based on their isotopic characteristics. Warm events are not associated with moist marine air intrusion, but with the downward flow of dry glacial air along the west side slope of the mountains in Enderby Land (EL). We use simulations from the Antarctic Mesoscale Prediction System (AMPS) to explore the atmospheric process responsible for the warmest event at Syowa. The model output illustrates several foehn-associated features such as low-level blocking, precipitation on the mountain's windward side, and mountain wave activity, with warm air ascending on the upstream slope and descending to Syowa. The foehn warming is caused by an easterly cross-mountain flow associated with a low-pressure system to the north of the EL coast. Future changes in synoptic cyclonic activity off the EL coast may have a significant impact on the frequency and intensity of foehn events at Syowa and the associated coastal warm events.