11 January 2018, Arctic cause of loopier cold weather? A QUICK SUMMARY: The Science Linking Arctic Warming to This Crazy-Cold Winter: It’s well known that the rapidly warming Arctic is melting sea ice, thawing permafrost, and accelerating sea-level rise. But a growing body of research suggests, counter intuitively, that it could also be amplifying cold snaps, much like the brutal one now freezing the East Coast. ANOTHER VIEW: US cold snap was a freak of nature, quick analysis finds. The cold snap that gripped the East Coast and Midwest region was a rarity that bucks the warming trend, said researcher Claudia Tebaldi of the National Center for Atmospheric Research and the private organization Climate Central.
Category Archives: The Science
5 January 2018, Science Journal, Beneath the waves, oxygen disappears. As plastic waste pollutes the oceans and fish stocks decline, unseen below the surface another problem grows: deoxygenation. Breitburg et al. review the evidence for the downward trajectory of oxygen levels in increasing areas of the open ocean and coastal waters. Rising nutrient loads coupled with climate change—each resulting from human activities—are changing ocean biogeochemistry and increasing oxygen consumption. This results in destabilization of sediments and fundamental shifts in the availability of key nutrients. In the short term, some compensatory effects may result in improvements in local fisheries, such as in cases where stocks are squeezed between the surface and elevated oxygen minimum zones. In the longer term, these conditions are unsustainable and may result in ecosystem collapses, which ultimately will cause societal and economic harm. Read More here
4 January 2018, Geophysical Research Letters, Decline in Antarctic Ozone Depletion and Lower Stratospheric Chlorine Determined From Aura Microwave Limb Sounder Observations. The Antarctic ozone hole is healing slowly because levels of the man-made chemicals causing the hole have long lifetimes. We use Microwave Limb Sounder (MLS) satellite data to measure O3 over Antarctica at the beginning of winter and then compare it to O3 near the end of winter to calculate depletion. During this period, nearly all O3 change is due to depletion. MLS also measures HCl, and when ozone levels are very low, nearly all the reactive chlorine species (Cly) are converted to HCl. Clyvaries a lot from year to year from atmospheric motions. Fortunately, MLS measures nitrous oxide (N2O), a long-lived gas that also varies with the motions. Using the ratio of Cly to N2O, we find that there is less chlorine now than 9 years ago and that Cly has decreased on average about 25 parts per trillion/yr (0.8%/yr). The O3 depletion we calculate from MLS data responds to changes in the Clylevels, and the ratio of the change in ozone loss to the change in Cly matches model calculations. All of this is evidence that the Montreal Protocol is working—the Cly is decreasing in the Antarctic stratosphere and the ozone destruction is decreasing along with it. Read More here
4 January 2018: The first complete temperature datasets for 2017 show that last year was the third in a row of exceptionally warm years, the Copernicus Climate Change Service (C3S) implemented by the European Weather Centre (ECMWF) can announce. One data set, produced by ECMWF, shows that the global average surface air temperature exceeded 14.7°C, making 2017:
- about 0.1°C cooler than the warmest year on record, 2016, and warmer than the previous second warmest year, 2015
- the warmest year on record not influenced by warming El Niño conditions in the tropical Pacific
- around 0.5°C warmer than the 1981–2010 climatological reference period
- an estimated 1.2°C warmer than the pre-industrial value for the 18th century.
Comparable results have been obtained by C3S from a reanalysis dataset produced by the Japan Meteorological Agency (JMA). The method used to produce the datasets is to combine millions of meteorological and marine observations, including from satellites, with models to produce a complete reanalysis of the atmosphere. The combination of observations with models makes it possible to estimate temperatures at any time and in any place across the globe, even in data-sparse areas such as the polar regions. The results support the provisional announcement by the World Meteorological Organization (WMO) two months ago that 2017 was set to be among the three warmest years on record. Other datasets used in the WMO announcement, which are derived from monthly climatological data for a smaller number of long-term observing sites, are also expected to concur when they are released shortly. All datasets will contribute to the consolidated statement to be issued by WMO on 2017 temperatures. Read More here