Greenland plays a large role in the gloomy picture painted of probable future sea-level rise

Goelzer et al (2012) paint a portentous picture of what is likely to happen to the global sea-level over the next 1000 years. This worrying assessment is based on our current best understanding of how the world's giant ice sheets of Greenland and Antarctica, as well as a quarter of a million smaller glacial ice masses, and the ocean collectively respond to ongoing climate change. Theirs is a state of the science study that integrates these key contributors of sea-level change based on the latest models and current understanding, and an integrated Earth systems modelling approach termed LOVECLIM. As they point out in their study, only a handful of global climate models to date—i.e. models that are used to make predictions of future climate change—incorporate dynamically (fully) coupled ice-sheet models

Global warming - some perspectives

Here the authors critically review the IPCC’s claim that global warming is “very likely” caused by human activity: such a description underestimates the likelihood of the warming being due to this mechanism. Next examined are known alternative “natural” mechanisms which could give rise to the warming if, despite many claims, the man-made explanation was false because of compensation effects (greenhouse gases versus aerosol effects). Also, a number of difficulties, as yet unresolved, in the human-induced warming explanation are considered

Surface air temperature fluctuations and lapse rates on Olivares Gamma Glacier, Rio Olivares basin, central Chile, from a novel meteorological sensor network

Empirically based studies of glacier meteorology, especially for the Southern Hemisphere, are relatively sparse in the literature. Here, we use an innovative network of highly-portable, low-cost thermometers to report on high-frequency (1-min time resolution) surface air temperature fluctuations and lapse rates (LR) in a ~800-m elevational range (from 3,675 to 4,492 m a.s.l.) across the glacier Olivares Gamma in the central Andes, Chile. Temperatures were measured during an intense field campaign in late Southern summer, 19–27 March 2015, under varying weather conditions. We found a complex dependence of high-frequency LR on time of day, topography and wider meteorological conditions, with hourly temperature variations during this week that were probably mainly associated with short- and long-wave radiation changes and not with wind speed/direction changes. Using various pairs of sites within our station network, we also analyze spatial variations in LR. Uniquely in this study, we compare temperatures measured at heights of 1-m and 2-m above the glacier surface for the network of five sites, and found that temperatures at these two heights occasionally differed by more than ±4°C during the early afternoons, although the mean temperature difference is much smaller (~0.3°C). An implication of our results is that daily, hourly, or even monthly-averaged LR may be insufficient for feeding into accurate melt models of glacier change, with the adoption of sub-hourly (ideally 1–10-min) resolution LR likely to prove fruitful in developing new innovative high-time-resolution melt modelling. Our results are useful potentially as input LR for local glacier melt models, and for improving the understanding of lapse-rate fluctuations and glacier response to climate change

Icelandic coastal sea surface temperature records constructed: putting the pulse on air-sea-climate interactions in the northern North Atlantic. Part I: Comparison with HadISST1 open-ocean surface temperatures and preliminary analysis of long-term patterns and anomalies of SSTs around Iceland

A new comprehensive record of long-term Icelandic sea surface temperature measurements, which have been updated and filled in with reference to air temperature records, is presented. The new SST series reveal important features of the variability of climate in Iceland and the northern North Atlantic. This study documents site histories and possible resulting inconsistencies and biases, for example, changes in observing sites and instruments. A new 119-yr continuous time series for north Iceland SST is presented, which should prove particularly useful for investigating air-sea ice interactions around northern Iceland. As this is the only part of the country to be regularly engulfed by winter and/or spring sea ice, it is therefore highly sensitive to climatic change. The coastal series correlate well overall with independent Hadley Centre Sea Ice and SST dataset version 1 (HadISST1) series from the adjacent open ocean (mean r = 0.59), although correlations are generally higher in summer than winter and for south and east Iceland compared with the west and north. The seasonal temperature range is generally twice as large at the coastal sites because of differential effects of radiation, melting, mixing, and advection of warmer or colder air or water masses, as well as spatial resolution differences and smoothing in HadISST1. The long-term climatological averages and graphs for the 10 SST stations and/or their composites reveal decadal variations and trends that are generally similar to Icelandic air temperature records: a cold late-nineteenth-century, rapid warming around the 1920s, an overall warm peak circa 1940, cooling until an "icy" period circa 1970, followed by warming. Regional differences between sites include relatively greater (lesser) long-term variations for the eastern and southern (western and northern) Icelandic coasts, suggesting greater variability and influence of ocean current advection in the southeast. Moreover, Vestmannaeyjar SST data reveal that the late-nineteenth-century cold period in the ocean was not confined to the cold currents off north and east Iceland but also affected the south coast markedly. The Stykkishólmur, Iceland, SST record is relatively noisy and shows very little decadal variation, which may largely be due to fjord ice in cold winters suppressing low temperatures. It is anticipated that researchers may find these Icelandic SST series of practical use as a historic measure of air-sea-climate interactions around Iceland. © 2006 American Meteorological Society

UJI SENSITIVITAS DAN SPESIFISITAS MENTZER INDEX, RED DISTRIBUTION WIDTH INDEX DAN GREEN AND KING INDEX TERHADAP DIAGNOSIS TALASEMIA BETA MINOR DAN ANEMIA DEFISIENSI BESI

Latar belakang: Anemia mikrositik hipokromik sering disebabkan oleh anemia defisiensi besi dan talasemia beta minor. Pemeriksaan baku emas talasemia beta adalah pemeriksaan genetik, sedangkan anemia defisiensi besi adalah pemeriksaan cadangan besi sumsum tulang. Kedua pemeriksaan tersebut memakan biaya yang mahal. Perlu adanya teknik skrining berupa indeks perhitungan yang adekuat dengan biaya yang terjangkau. Tujuan: Mengetahui dan membandingkan nilai sensitivitas dan spesifisitas Mentzer Index, Red Distribution Width Index dan Green and King Index. Metode: Penelitian ini merupakan penelitian uji diagnostik. Terdapat 98 data anemia mikrositik hipokromik yang terdiri dari masing-masing 49 anemia defisiensi besi dan talasemia beta minor. Dilakukan perhitungan Mentzer index, Red Distribution Width Index dan Green and King Index yang dibandingkan dengan parameter diagnosis untuk mengetahui nilai sensitivitas dan spesifisitas. Parameter diagnosis emas yaitu ferritin serum atau TIBC atau besi serum untuk diagnosis anemia defisiensi besi dan hemoglobin A2 untuk diagnosis talasemia beta minor. Hasil: Mentzer index memiliki nilai sensitivitas dan spesifisitas untuk mendeteksi anemia defisiensi besi sebesar 93,88% dan 87,76%, dan talasemia beta minor sebesar 87,76% dan 93,88%. RDWI index memiliki nilai sensitivitas dan spseifisitas untuk medeteksi anemia defisiensi besi sebesar 89,80% dan 83,67%, dan untuk talasemia beta minor sebesar 83,67% dan 89,80%. Green and King index memiliki nilai sensitivitas dan spesifisitas anemia defisiensi besi sebesar 91,84% dan 77,55%, dan untuk talasemia beta minor sebesar 77,55% dan 91,84%. Kesimpulan: Mentzer index memiliki nilai sensitivitas dan spesifisitas tertinggi sehingga dapat digunakan sebagai teknik skrining untuk mendiagnosis talasemia beta minor dan anemia defisiensi besi. Kata kunci: anemia defisiensi besi, talasemia beta minor, Mentzer Index, Red Distribution Width Index, Green and King Inde

Observed and modeled Greenland ice sheet snow accumulation, 1958-2003, and links with regional climate forcing

Author Posting. © American Meteorological Society 2006. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 19 (2006): 344–358, doi:10.1175/JCLI3615.1.Annual and monthly snow accumulation for the Greenland Ice Sheet was derived from ECMWF forecasts [mainly 40-yr ECMWR Re-Analysis (ERA-40)] and further meteorological modeling. Modeled accumulation was validated using 58 ice core accumulation datasets across the ice sheet and was found to be 95% of the observed accumulation on average, with a mean correlation of 0.53 between modeled and observed. Many of the ice core datasets are new and are presented here for the first time. Central and northern interior parts of the ice sheet were found to be 10%–30% too dry in ERA-40, in line with earlier ECMWF analysis, although too much (>50% locally) snow accumulation was modeled for interior southern parts of Greenland. Nevertheless, 47 of 58 sites show significant correlation in temporal variability of modeled with observed accumulation. The model also captures the absolute amount of snow accumulation at several sites, most notably Das1 and Das2 in southeast Greenland. Mean modeled accumulation over the ice sheet was 0.279 (standard deviation 0.034) m yr−1 for 1958–2003 with no significant trend for either the ice sheet or any of the core sites. Unusually high accumulation in southeast Greenland in 2002/03 leads the authors to study meteorological synoptic forcing patterns and comment on the prospect of enhanced climate variability leading to more such events as a result of global warming. There is good agreement between precipitation measured at coastal meteorological stations in southern Greenland and accumulation modeled for adjacent regions of the ice sheet. There is no significant persistent relation between the North Atlantic Oscillation index and whole or southern Greenland accumulation.JM acknowledges support from NASA’s Cryospheric Sciences Program and the Arctic Section of NSF’s Office of Polar Programs

Anomalous peak in Antarctic sea-ice area, winter 1998, coincident with ENSO

The results of an updated satellite analysis of hemispheric and regional Antarctic sea-ice cover are presented based on October 1987-September I999 Special Sensor Microwave/Imager (SSM/I) data. These show an ongoing slight but significant hemispheric increase of 3.7(±0.3) in extent and 6.6(±1.5) in area. In the two principal sectors, Weddell Sea ice extent (area) decreased by 3.4(±1.0) (3.9(±4.6)) and Ross Sea ice extent (area) increased by 10.9(±1.0) (18.3(±4.6)). Hemispheric, Ross Sea and Western Pacific Ocean ice peaks in September 1998 were anomalously high, and may have been related to atmospheric and oceanic anomalies in the Pacific Ocean and beyond associated with that year's exceptionally strong ENSO. Preliminary comparison of Antarctic sea-ice-concentration data with European Centre for Medium-Range Weather Forecasts (ECMWF) operational analyses fields suggests that the unusually extensive sea ice in winter 1998 was concomitant with an equatorward shift of the circumpolar westerly surface winds over the southern Pacific Ocean

Anomalous peak in Antarctic sea-ice area, winter 1998, coincident with ENSO

The results of an updated satellite analysis of hemispheric and regional Antarctic sea-ice cover are presented based on October 1987-September I999 Special Sensor Microwave/Imager (SSM/I) data. These show an ongoing slight but significant hemispheric increase of 3.7(±0.3) in extent and 6.6(±1.5) in area. In the two principal sectors, Weddell Sea ice extent (area) decreased by 3.4(±1.0) (3.9(±4.6)) and Ross Sea ice extent (area) increased by 10.9(±1.0) (18.3(±4.6)). Hemispheric, Ross Sea and Western Pacific Ocean ice peaks in September 1998 were anomalously high, and may have been related to atmospheric and oceanic anomalies in the Pacific Ocean and beyond associated with that year's exceptionally strong ENSO. Preliminary comparison of Antarctic sea-ice-concentration data with European Centre for Medium-Range Weather Forecasts (ECMWF) operational analyses fields suggests that the unusually extensive sea ice in winter 1998 was concomitant with an equatorward shift of the circumpolar westerly surface winds over the southern Pacific Ocean