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+--- Thread: July 2016 warmest on record + Thin tropical clouds cool climate (/thread-2731.html)
July 2016 warmest on record + Thin tropical clouds cool climate - C C - Aug 17, 2016
July 2016 was warmest on record, NASA analysis finds
https://www.sciencedaily.com/releases/2016/08/160817085303.htm
RELEASE: July 2016 was the warmest July in 136 years of modern record-keeping, according to a monthly analysis of global temperatures by scientists at NASA's Goddard Institute for Space Studies (GISS) in New York.
Because the seasonal temperature cycle peaks in July, it means July 2016 also was warmer than any other month on record. July 2016's temperature was a statistically small 0.1 degrees Celsius warmer than previous warm Julys in 2015, 2011 and 2009.
"It wasn't by the widest of margins, but July 2016 was the warmest month since modern record keeping began in 1880," said GISS Director Gavin Schmidt. "It appears almost a certainty that 2016 also will be the warmest year on record."
The record warm July continued a streak of 10 consecutive months dating back to October 2015 that have set new monthly high-temperature records. Compared to previous years, the warmer global temperatures last month were most pronounced in the northern hemisphere, particularly near the Arctic region.
The monthly analysis by the GISS team is assembled from publicly available data acquired by about 6,300 meteorological stations around the world, ship- and buoy-based instruments measuring sea surface temperature, and Antarctic research stations. The modern global temperature record begins around 1880 because previous observations didn't cover enough of the planet.
Thin tropical clouds cool the climate
https://www.sciencedaily.com/releases/2016/08/160817090614.htm
RELEASE: Thin clouds at about 5 km altitude are more ubiquitous in the tropics than previously thought and they have a substantial cooling effect on climate. This is shown in a recent study by researchers from Stockholm University and the University of Miami published in Nature Communications. The cooling effect of mid-level clouds is currently missing in global climate models.
"Using the satellite observations and high-resolution numerical modelling, we find that thin mid-level clouds are frequently formed in the tropics in the vicinity of deep convective clouds and that their cooling effect could be as large as the warming induced by high cirrus clouds," says lead author of the study Quentin Bourgeois, postdoctoral associate at the Department of Meteorology (MISU) and the Bolin Centre for Climate Research, Stockholm University.
Clouds play a pivotal role in determining Earth's climate and radiation budget, yet we still have a lot to learn about them. In particular, little is known about mid-level clouds, i.e. clouds located at approximately 5 km altitude, as these clouds are challenging to study.
"To bridge our gaps in knowledge about thin mid-level clouds we used space-borne lidar instruments that provide detailed information on the vertical distribution of clouds," says Quentin Bourgeois.
The scientists anticipate that their study will trigger further interest in thin mid-level clouds, which have been neglected for too long. In particular, the mechanism of their formation is not well understood yet. The authors also hope that the climate research community will factor in clouds in climate models more often in the future so that projections of climate change will become more accurate.
Clouds effects on global climate
Clouds cover about 70% of Earth's surface at any time. Different types of clouds affect Earth's climate differently: low liquid clouds, such as the cotton-like cumulus, cool Earth while high altitude ice clouds, such as the wispy cirrus, warm the climate. Overall, clouds cool the climate by about 20 W m-2. In contrast, Earth receives on average about 340 W m-2 energy from the sun every day and our current emissions of anthropogenic greenhouse gases warm the climate by about 3 W m-2.
RE: July 2016 warmest on record + Thin tropical clouds cool climate - scheherazade - Aug 29, 2016
The Yukon has been experiencing considerably milder winters in recent years and the people who live on the land are reporting that freeze up of waterways is happening later, an important consideration for remote villages who rely on those frozen water routes for winter transportation of goods and services.
Our summers have also been changing although more to the cool and damp side the last several years with this one being an exception. Gardeners were able to plant on average two weeks earlier than usual and we have not yet had a frost in the greater Whitehorse area so that would likely be close to a record for the number of frost free growing days in this region, which has ever been the limiting factor for commercial agriculture.
From the looks of the long term forecast, the rest of my log cabin is not going to get treated with preservative this season. Oh well, the product will keep and I did get the most important part tended, the bottom logs which experience the most contact with moisture.