Tag Archives: Antarctica

Seabed volcanoes influence West Antarctic glacier melts

“New evidence now updates and confirms a column I wrote in June 2014 that some or all of the highly publicized melting of western coastal Antarctic glaciers may be caused by seabed volcanoes rather than having much or anything to do with climate change.” click here

How to lie with maps and data smoothing – NASA

“Here is an infographic I prepared that illustrates the problem. There’s only one datapoint, the Amundsen-Scot south pole station, where there data from it is being smeared over a 1200 kilometer radius in the image above on Reddit, but in the image below, using the controls available at NASA GISTEMP, set to the 250 kilometer smoothing, we can see lots of missing data in Antarctica:” click here

Only mm of sea level rise expected if Antarctic ice shelf melts

“The new study shows that a collapse of Larsen C would result in inland ice discharging about 4 mm to sea level, while the response of glaciers to George VI collapse could contribute over five times more to global sea levels, around 22 mm.” click here

Lowest surface temperature on earth measured near East Antarctic divide

Scambos, T.A., Campbell, G.G., Pope, A., Haran, T., Muto, A., Lazzara, M., et al. (2018). Ultralow surface temperatures in East Antarctica from satellite thermalinfrared mapping: The coldest places on Earth. Geophysical Research Letters, 45. https://doi.org/10.1029/2018GL078133

We identify areas near the East Antarctic ice divide where <−90 °C surface snow temperatures are observed in wintertime satellite thermal‐band data under clear‐sky conditions. The lowest temperatures are found in small (<200 km2) topographic basins of ~2 m depth above 3,800 m elevation. Approximately 100 sites have observed minimum surface temperatures of ~−98 °C during the winters of 2004–2016. Comparisons of surface snow temperatures with near‐surface air temperatures at nearby weather stations indicate that ~−98 °C surfaces imply ~−94 ± 4 °C 2‐m air temperatures. Landsat 8 thermal band data and elevation data show gradients near the topographic depressions of ~6 °C km−1 horizontally and ~4 °C m−1 vertically. Ultralow temperature occurrences correlate with strong polar vortex circulation. We discuss a conceptual model of radiative surface cooling that produces an extreme inversion layer. Further cooling occurs as near‐surface cold air pools in shallow high‐elevation topographic basins, moderated by clear‐air downwelling radiation and heat from subsurface snow.

Antarctic ice on the increase

“Despite all the alarmist claims of an Antarctic meltdown, it is well known that the trend for sea ice extent at the South Pole has been one of growing ice rather than shrinking ice over the past 4 decades.” click here

Antarctic Penguins are doing just fine, thank you

“The 1.5 million penguins were spotted on the Danger Islands, a chain of nine rocky islands off the Antarctic Peninsula’s tip, near South America.” click here

Belief in Ice Core Projections of the Antarctic Past Requires Great Faith

Addendum: If we assume ice core projections represent the past then Antarctic region temperatures are decreasing not increasing as climate models claim. (click here)

Barbara Stenni, Mark A. J. Curran, Nerilie J. Abram, Anais Orsi, Sentia Goursaud, Valerie Masson-Delmotte, Raphael Neukom, Hugues Goosse, Dmitry Divine, Tas van Ommen, Eric J. Steig, Daniel A. Dixon, Elizabeth R. Thomas, Nancy A. N. Bertler, Elisabeth Isaksson, Alexey Ekaykin, Martin Werner, and Massimo Frezzotti. Antarctic climate variability on regional and continental scales over the last 2000 years. Climate of the Past, 13, 1609–1634, 2017 https://doi.org/10.5194/cp-13-1609-2017

Climate trends in the Antarctic region remain poorly characterized, owing to the brevity and scarcity of direct climate observations and the large magnitude of interannual to decadal-scale climate variability. Here, within the framework of the PAGES Antarctica2k working group, we build an enlarged database of ice core water stable isotope records from Antarctica, consisting of 112 records. We produce both unweighted and weighted isotopic (δ 18O) composites and temperature reconstructions since 0 CE, binned at 5- and 10-year resolution, for seven climatically distinct regions covering the Antarctic continent. Following earlier work of the Antarctica2k working group, we also produce composites and reconstructions for the broader regions of East Antarctica, West Antarctica and the whole continent. We use three methods for our temperature reconstructions: (i) a temperature scaling based on the δ 18O–temperature relationship output from an ECHAM5-wiso model simulation nudged to ERA-Interim atmospheric reanalyses from 1979 to 2013, and adjusted for the West Antarctic Ice Sheet region to borehole temperature data, (ii) a temperature scaling of the isotopic normalized anomalies to the variance of the regional reanalysis temperature and (iii) a composite-plusscaling approach used in a previous continent-scale reconstruction of Antarctic temperature since 1 CE but applied to the new Antarctic ice core database. Our new reconstructions confirm a significant cooling trend from 0 to 1900 CE across all Antarctic regions where records extend back into the 1st millennium, with the exception of the Wilkes Land coast and Weddell Sea coast regions. Within this long-term cooling trend from 0 to 1900 CE, we find that the warmest period occurs between 300 and 1000 CE, and the coldest interval occurs from 1200 to 1900 CE. Since 1900 CE, significant warming trends are identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the Antarctic Peninsula regions, and these trends are robust across the distribution of records that contribute to the unweighted isotopic composites and also significant in the weighted temperature reconstructions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of natural variability over the last 2000 years. However, projected warming of the Antarctic continent during the 21st century may soon see significant and unusual warming develop across other parts of the Antarctic continent. The extended Antarctica2k ice core isotope database developed by this working group opens up many avenues for developing a deeper understanding of the response of Antarctic climate to natural and anthropogenic climate forcings. The first long-term quantification of regional climate in Antarctica presented herein is a basis for data–model comparison and assessments of past, present and future driving factors of Antarctic climate.