WEEKLY CLIMATE NEWS

DataStreme ECS Week Twelve: 28 November-2 December 2016

ITEMS OF INTEREST

Worldwide GLOBE at Night 2016 Campaign is underway -- The twelfth in the series of GLOBE at Night citizen-science campaigns for 2016 will continue through Wednesday, 30 November. GLOBE at Night is a worldwide, hands-on science and education program designed to encourage citizen-scientists worldwide to record the brightness of their night sky by matching the appearance of a constellation (Perseus in the Northern Hemisphere and Grus in the Southern Hemisphere) with the seven magnitude/star charts of progressively fainter stars. Activity guides are also available. The GLOBE at night program is intended to raise public awareness of the impact of light pollution. The next and final series in the 2016 campaign is scheduled for 20-30 December 2016. [GLOBE at Night]
Beginning of meteorological winter season -- The winter meteorological season in the Northern Hemisphere starts on Thursday (1 December). Recall that climatologists and meteorologists have elected to use a standard three-month grouping to identify each meteorological season. Hence, the months of December, January and February are considered the winter meteorological season. You will note that the winter solstice, marking the day where the length of daylight is least in the Northern Hemisphere is still three weeks away, falling on Wednesday, 21 December 2016. Since the lowest temperatures typically fall in mid to late January, the meteorological winter tends to be centered on the coldest time of the year in the Northern Hemisphere.
In addition, Wednesday (30 November) marked the end of the official 2016 hurricane seasons in the North Atlantic, which includes the Gulf of Mexico and the Caribbean, along with the eastern and central North Pacific basins.
The 2016 hurricane seasons reviewed -- With the end of the official 2016 hurricane season in both the North Atlantic and North Pacific on Wednesday (30 November 2016), a quick review of this year's tropical cyclone statistics for the official 2016 hurricane season has been made for both basins. [AMS DataStreme Atmosphere]
For those who are interested in obtaining historic hurricane information, the "Historical Hurricanes Mapping & Analysis Tool" developed by NOAA allows the search and display of detailed data for more than 6000 tropical cyclones in seven of the planet's major ocean basins based upon a data set that runs from 1842 to 2015. Coastal population trends are also available for the Atlantic and Gulf Coasts of the United States.
Tropical cyclone climatologies of North Atlantic and the eastern North Pacific -- The National Hurricane Center (NHC) has an updated and revised edition of its "Tropical Cyclones of the North Atlantic Ocean, 1851-2006." While a paper copy of this book is available for a cost from NHC, a 243-pg pdf file of this edition can be downloaded for free. NHC also released the first edition of "Tropical Cyclones of the Eastern North Pacific Ocean, 1949-2006." In addition to a paper copy is available for sale, a free 164-page pdf file is available. Both of these climatologies have numerous graphics that show long-term changes in tropical cyclone frequency in the two basins.
A climatology of tropical cyclones in the central North Pacific from the 1950s to 2013 is available from the CPHC climatology website maintained by the Central Pacific Hurricane Center (CPHC) in Honolulu, HI.
High-quality maps of December temperature and precipitation normals across US available -- The PRISM Climate Group at Oregon State University's website has prepared high-resolution maps depicting the normal maximum, minimum and precipitation totals for December and other months across the 48 coterminous United States for the current 1981-2010 climate normals interval. These maps, with a 800-meter resolution, were produced using the PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate mapping system.
December weather calendar for a city near you -- The Midwestern Regional Climate Center maintains an interactive website that permits the public to produce a ready to print weather calendar for any given month of the year, such as December, at any of approximately 270 weather stations around the nation. (These stations are NOAA's ThreadEx stations.) The entries for each day of the month includes: Normal maximum temperature, normal minimum temperature, normal daily heating and cooling degree days, normal daily precipitation, record maximum temperature, record minimum temperature, and record daily precipitation; the current normals for 1981-2010.
"Coldest day of the year" is on the horizon -- NOAA's National Centers for Environmental Information (NCEI) produced a set of "Coldest Day of the Year" maps for the contiguous United States, Alaska, Hawaii and Puerto Rico showing the dates of the lowest daily minimum temperatures of the year as calculated from the 1981-2010 climate normals. Many places across the West will experience their lowest daily temperatures starting during the next two to three weeks in early December. On the other hand, some areas across the West will not reach their lowest daily temperatures of the year until late January. [NOAA NCEI News]
[Notes: (1.) According to the seasonal variations in the long-term average or "normal" temperatures, many locations across the nation not along the coasts typically have their lowest normal daily high and low temperatures during the third week of January, nearly one month after the winter solstice. However, areas across the West have their lowest temperatures during the month of December, with elevation becoming an influence.
(2.) For comparison purposes, check the corresponding NCEI map for the "Warmest Day of the Year" that shows the dates of occurrence of the highest maximum temperatures. EJH]
It's Sure Dark! -- Have you noticed that the sun is setting early these days? During the first ten days of December, many locations throughout the country will experience their earliest sunset times of the year. The exact day for the earliest sunset depends upon the latitude, so you may want to check the date in your locale from the sunrise tables appearing in an on-line, interactive service available for the entire year at most cities in the United States. The reason for the earliest sunsets occurring in early December rather than on the winter solstice (during the early morning hours of Wednesday, 21 December 2016) is that the sun is not as precise a timekeeper as our watches. Because of a combination of factors involved with Earth's elliptical orbit about the sun and the tilt of Earth's spin axis with respect to the plane of the ecliptic, the sun appears to "run fast" by as much as 15 minutes as compared with clock time in November. However, with the approach of the winter solstice and perihelion (the smallest earth-sun distance during the morning of 4 January 2017), the apparent sun slows during December and finally lags the clock by 12 minutes in February. Consequently, a noticeable and welcome trend toward later sunsets can be detected by the end of December, especially by those residents in the northern part of the country. However, the latest sunrises occur at most locales in early January, meaning that early risers will continue seeing dark and dreary mornings for another month.
State, national and global instrumental records -- Temperature and precipitation data have been collected around the world since the mid-19th century. Beginning in the 1890s, a sufficiently dense climate network has been established in the United States and its territories. The records from around the nation and from around the global have been collected and archived at several central locations, such as NOAA's National Centers of Environmental Information (NCEI). Scientists at NCEI along with colleagues at NASA's Goddard Institute for Space Studies and in the United Kingdom have produced time series of area-average monthly and annual temperatures for over a century on state, national and global space scales. For more details on these records and how to access them, please read this week's Supplemental Information...In Greater Depth.
Graphical depictions of statewide annual and seasonal time series are available -- NOAA's National Centers for Environmental Information (NCEI) are making graphics available that depict the variations in the historical temperature averages each year or each season since 1895 for each of the 48 contiguous United States. These graphs are derived from the current nClimDiv version of the US Climate Division Database. [NOAA NCEI News]

CURRENT CLIMATE STATUS

Review of October 2016 global temperatures and sea ice cover -- Preliminary data analyzed by scientists at NOAA's National Centers for Environmental Information (NCEI) indicated that the global combined land and ocean average surface temperature for the October 2016 was 1.31 Fahrenheit degrees above the 20th century average (1901-2000) for the month. Therefore, last month's global combined temperature tied the temperature for October 2003 for being the third highest October temperature since global temperature records began in 1880. When considered separately, the monthly average temperature over the global oceans for October 2016 was 1.30 Fahrenheit degrees above average, the second highest October ocean temperature in 137 years of record. The monthly average temperature of the land surface for this recently concluded month was 1.37 Fahrenheit degrees above average, which represented the 16th highest October land surface temperature on record. The global combined temperature for October 2016 was 0.47 Fahrenheit degrees lower than the record high global temperature for the previous year (October 2015) when a major El Niño event was peaking, with large-scale warming of the eastern and central equatorial Pacific Ocean.
Although October temperatures had dropped slightly, when considering the combined land-ocean global temperature for the year to date (January-October 2016), this temperature was the highest global temperature for the first ten months of any year since 1880, exceeding the previous record high temperature for the corresponding ten-month interval set only one year ago by 0.18 Fahrenheit degrees. [NOAA/NCEI State of the Climate]
A global map of Selected Significant Climate Anomalies and Events for October 2016 is available from NCEI.
According to satellite data collected by National Snow and Ice Data Center, the sea ice over the Arctic Ocean during October 2016 was the smallest areal extent for any October since satellite-derived ice records began in 1979. The sea ice around Antarctica was the second smallest October ice extent in the last 38 years. Globally, the sea ice extents in both the Northern and Southern Hemisphere was the smallest October global sea ice extent on record. [NOAA/NCEI Global Snow & Ice]

CURRENT CLIMATE MONITORING

New insights into global warming trends are provided -- A research paper was recently published by a team of scientists from the University of Delaware, NASA's Jet Propulsion Laboratory and several other institutions addressed the phenomenon that has been referred to as the "global warming hiatus" in which a temporary slowdown in the global average surface temperature warming trend was observed between 1998 and 2013. The researchers discussed a new understanding of this phenomenon, concluding the phenomenon represented a redistribution of energy within the Earth system, with Earth's ocean absorbing the extra heat. They also noted that "the rate of global surface warming can fluctuate due to natural variations in the climate system over periods of a decade or so." Furthermore, they called for continued support of current and future technologies for ocean monitoring to reduce observation errors in sea surface temperature and ocean heat content. [NASA Jet Propulsion Laboratory Feature]

CLIMATE AND THE BIOSPHERE

Decoding signals of climate change where trees meet tundra -- Scientists from Columbia University's Lamont-Doherty Earth Observatory and other institutions are engaged in a long-term project in north central Alaska near the Brooks Range that is designed to determine what allows trees to survive in the borderline environment between the boreal forest and open tundra. Since temperature is known as a driving environmental factor in ecosystems, changes in temperature in the arctic are suspected to affect the position of the tree-line or boundary between forest and tundra. Other factors include availability of light, precipitation and snow cover. Since the climate is warming in the arctic and subarctic at rates that are at least two to three times faster than the global average, a rapid northward migration of the tree-line is suspected to occur in the next few decades. The research project in the Brooks Range is part of the larger Arctic Boreal Vulnerability Experiment (ABoVE), a multi-year project that involves combining satellite imagery with fine-scale ground observations in the vicinity of the tree-line to create a visualization of how the region may change in the future. [Lamont-Doherty Earth Observatory News]
Human-caused carbon dioxide emissions linked to dissolving of sea snail shells off West Coast -- A team of scientists from the NOAA Pacific Marine Environmental Laboratory, the University of Washington, Oregon State University, the University of California Davis and the University of South Florida recently reported finding a connection between the concentration of human-caused carbon dioxide dissolved in waters off the US Pacific Coast and the to the dissolving of shells of "pteropods", or microscopic marine sea snails. The researchers estimated that carbon dioxide concentrations from fossil fuel emissions comprise as much as 60 percent of the carbon dioxide that enriches most West Coast near-shore surface waters, although concentrations drop with depth. They based their findings upon analysis of pteropods shells collected during West Coast research cruises in the years between 2007 and 2013. Pteropods are a major part of the diet of commercially valuable fish such as salmon, sablefish and rock sole. [NOAA Office of Oceanic & Atmospheric Research News]

CLIMATE FORCING

An introduction is made to the Pacific Meridional Mode -- Dan Vimont, a professor with the University of Wisconsin-Madison's Center for Climatic Research wrote a guest post to the ClimateWatch Magazine in which he introduces the concept of "Pacific Meridional Mode," a north-south or meridional pattern involving the interactions between ocean and atmosphere across the Pacific characterized by an anomalous sea surface temperature (SST) gradient across the mean latitude of the Intertropical Convergence Zone (ITCZ), coupled to an anomalous displacement of the ITCZ toward the warmer hemisphere. The Pacific Meridional Mode, along with a corresponding Atlantic Meridional Mode, consists of interannual-decadal variability in the tropical ocean basins that appear to be forced by trade wind variations in their respective northern subtropical oceans. The Pacific meridional mode appears to exist independently of El Niño-Southern Oscillation (ENSO), although ENSO nonlinearity projects strongly on it during the peak anomaly season of boreal spring. Dan also discusses the role that the Pacific Meridional Mode had with the strong 2015-16 El Niño event. [NOAA Climate.gov News]
Human contribution to atmospheric carbon dioxide levels is detected by satellite -- A team of scientists have used data collected from 2014 to 2016 by the sensors onboard NASA's Orbiting Carbon Observatory-2 (OCO-2) to determine the global concentrations of carbon dioxide gas in the atmosphere and identify a human signal amid the seasonal fluctuations of this greenhouse gas. OCO-2 was launched in July 2014. Satellite-based maps of human emissions of carbon dioxide have been produced by a group of scientists from the Finnish Meteorological Institute. These maps depict widespread carbon dioxide around major urban areas, with the highest values of carbon dioxide emissions observed over eastern China, with other hot spots in the eastern United States, Central Europe, the Middle East, and Japan. [NASA Earth Observatory]

CLIMATE FORECASTS

Australian tropical cyclone season outlook issued -- Forecasters at the Australian Government's Bureau of Meteorology recently released an outlook for the upcoming 2016-17 Australian tropical cyclone season that typically begins in November and runs through April. These forecasters foresee an above-average tropical cyclone activity in the five regions that surround that continent, with the best chances for the above-average numbers of tropical cyclones being in the Australian region in the south central section of the country (with a 67- percent chance) and the Northwestern sub-region (63-percent chance). Their outlook for a more active season is based upon a transition from ENSO-neutral to weak La Niña conditions across the tropical Pacific Ocean, together with warmer than average ocean waters located to the north and east of Australia. Typically, the waters around Australia experience more tropical cyclones during La Niña events. [Australian Bureau of Meteorology]

CLIMATE AND SOCIETY

United Nations climate change conference adjourns with promise of continued action -- The twenty-second session of the Conference of the Parties (COP 22), the twelfth session of the Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol (CMP 12), and the first session of the Conference of the Parties serving as the meeting of the Parties to the Paris Agreement (CMA 1) were held recently in Bab Ighli, Marrakech, Morocco from 7-18 November 2016. The Conference appears to be successful in that a constructive spirit of multilateral cooperation on climate change continues with participating countries presenting a united front with a pledge to forge ahead in the fight against climate change. They also issued a call to President-elect Donald Trump to join them. While climate finance remained an unresolved issue, nearly 200 countries have agreed to develop an emissions reduction rule book by 2018 and 47 of world’s poorest countries pledged to meet all their domestic energy needs from renewables as rapidly as possible. Big emitters such as Britain and Australia ratified the Paris Agreement during COP22, bringing the total to 111 countries with 77 percent of world’s emissions now officially backing the deal. [United Nations Framework Convention on Climatic Change COP22]
Earthweek -- Diary of the Planet [earthweek.com]

Concept of the Week: Climate Sensitivity

Climate sensitivity is a relatively new and powerful concept in climate science. It is a measure of how responsive the temperature of Earth's climate system is to a change in radiative forcing due to increases in atmospheric carbon dioxide, an important greenhouse gas, combined with the contributions of feedbacks within the system. Specifically, the term is defined as how much the global mean surface temperature will increase if there is a doubling of atmospheric greenhouse gases (in terms of equivalent CO₂), once the planet has had a chance to settle into a new equilibrium after the increase occurs. In other words, it's an assessment of how Earth's climate will respond to that doubling.

According to NASA climate scientist James Hansen, the concept of climate sensitivity has its origins in a request made by President Jimmy Carter in 1979 for the National Academy of Sciences (NAS) to report on the potential impact on climate of the increasing atmospheric concentration of carbon dioxide. Jule G. Charney (1917-1981) of the Massachusetts Institute of Technology (MIT) led the Academy investigation team. He designed a now classic experiment where computer models of Earth's climate system had the atmospheric concentration of CO₂ doubled while all other variables (except temperature) were held constant.

The addition of CO₂ makes the atmosphere more opaque for outgoing infrared radiation (heat), warming the lower atmosphere and cooling the upper atmosphere. Applying basic radiation laws, Charney found that doubling the atmospheric CO₂ concentration would reduce the net radiative flux (from Earth to space) at the tropopause by a global average of about 4 watts per square meter (W/m²). How much warmer would Earth's surface become as a consequence of this enhanced greenhouse effect? According to the Stefan-Boltzmann law, the radiation emitted by an object is directly proportional to the fourth power of the object's absolute temperature. To reestablish radiative equilibrium following a doubling of atmospheric CO₂, Earth must radiate to space an additional 4 W/m², brought about by a global warming of 1.2 Celsius degrees (or 0.3 Celsius degrees per W/m²).

Charney's initial experiment accounted for the effect of a forcing agent (i.e., atmospheric CO₂) on global climate but not the influence of feedbacks. As noted in the Concept of the Week for Week 2, forcing agents and mechanisms drive climate change, while feedbacks determine the magnitude of climate change. Hence, Charney's "no-feedback" experiment significantly underestimates the amount of global warming likely to accompany a doubling of atmospheric CO₂. With inclusion of feedbacks, the 1979 Academy study indicated that global warming could range from 2 to 3.5 Celsius degrees. The most recent IPCC report (AR4) estimates the magnitude of warming with feedbacks incorporated as 3 Celsius degrees with a range of uncertainty of 2 to 4.5 Celsius degrees. This greater sensitivity depends primarily on all the different feedbacks, both positive and negative, that either amplify or diminish the greenhouse effect. The three primary feedbacks involve clouds, sea ice, and water vapor.

In summary, climate sensitivity is usually expressed in terms of the equilibrium change in global mean annual surface temperature caused by an increment in downward infrared radiative flux that would result from sustained doubling of atmospheric CO₂ concentration compared to its pre-industrial level (taken to be 280 ppmv).

Concept of the Week: Questions

All other factors being equal, the addition of CO₂ to the atmosphere [(increases) (decreases)(has no effect upon)] the flux of infrared radiation from Earth's surface to space.
Charney's initial estimate of the amount of global warming that would accompany a doubling of atmospheric CO₂ [(did)(did not)] account for the temperature change(s) likely to accompany feedbacks in Earth's climate system.

Historical Events:

29 November 1975...Red River was buried under 34 inches of snow in 24 hours, establishing a record for the state of New Mexico. (The Weather Channel)
29 November 1985...The temperature at Bismarck, ND plunged to 30 degrees below zero to establish their record low for the month of November. The high that day was 4 degrees below zero. (The Weather Channel)
29 November 1989...Sault Ste Marie, MI finished the month of November with a record 46.8 inches of snow. (The National Weather Summary) (Storm Data)
30 November 1976...MacLeod Harbor, AK reported a precipitation total for November of 70.99 inches, which established a state record for any month of the year. (The National Weather Summary)
30 November 1991...Minneapolis, MN ended the month with 46.9 inches of snow, the most ever for November and for any month. Although the official start of winter was still 3 weeks away, the city had already surpassed the normal seasonal snowfall record with 55.1 inches since 1 October (normal for the entire winter is 49.2 inches). (Intellicast)
30 November 2001...For the first time in 122 years of weather records, Buffalo, NY finished the entire month of November without any snowfall. (National Weather Service files)
1 December 1831...The coldest December of record in the northeastern U.S. commenced. Temperatures in New York City averaged 22 degrees, with just four days above freezing, and at Burlington, VT the temperature never did get above freezing. The Erie Canal was closed the first day of December, and remained closed the entire month. (David Ludlum)
1 December 1913...A six day Front Range snowstorm began, ultimately producing 45.7 inches of snow at Denver, CO, the biggest single snowstorm on record for that city. It produced a record total of 46 inches at Denver, CO. (David Ludlum) (Intellicast)
3-10 December 1926...Record rain fell on Yuma, AZ over a one-week period. On the 4^th 1.10 inches of rain fell, and by the 10^th a total of 4.43 inches had fallen, to set an all-time December monthly record. The mean annual precipitation for Yuma is only 3.38 inches. (Accord Weather Guide Calendar)
3 December 1982...Big Fork, AR received 14.06 inches of rain, setting a 24-hour maximum precipitation record for the state. (NCDC)
4 December 1982...The temperature in New York City's Central Park reached 72 degrees to establish a record high for December. The month as a whole was also the warmest of record. (The Weather Channel)

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