WEEKLY CLIMATE NEWS

26-30 November 2018

ITEMS OF INTEREST

Second volume of latest national climate assessment report just released -- This past Friday, the U.S. Global Change Research Program that consists of thirteen U.S. government agencies released "Volume II: Impacts, Risks, and Adaptation in the United States" of its 4^th National Climate Assessment (NCA4), which is a Congressionally mandated quadrennial report about how climate change is impacting the United States. This second volume of the NCA4 report follows the Climate Science Special Report, known as "Volume I of the Fourth National Climate Assessment," which was released in November 2017. The just-released second volume of the NCA4 report focuses on the impacts and risks associated with climate change for U.S. sectors (such as agriculture, health, transportation and energy) and regions of the nation. A detailed picture is presented of how communities across the country are already feeling the effects of climate change, together with what impacts U.S. residents could expect if drastic action were not taken to address climate change. Additional discussion and analysis will be forthcoming. [Union of Concerned Scientists Press Release]
Worldwide GLOBE at Night 2018 Campaign for December commences -- The twelfth in a series of GLOBE at Night citizen-science campaigns for 2018 will commence this Thursday (29 November) and continue through Saturday, 8 December. 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 with the seven magnitude/star charts of progressively fainter stars. These constellations are Perseus in the Northern Hemisphere and Grus for the Southern Hemisphere. Activity guides are also available. The GLOBE at night program is intended to raise public awareness of the impact of light pollution. The first series in the 2019 campaign is scheduled for 29 December-7 January 2019. [GLOBE at Night]
Beginning of meteorological winter season -- The winter meteorological season in the Northern Hemisphere starts on Saturday (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 Friday, 21 December 2018. 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, Friday (30 November) marks the end of the official 2018 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 2018 hurricane seasons reviewed -- With the end of the official 2018 hurricane season in both the North Atlantic and North Pacific on Friday (30 November 2018), a quick review of this year's tropical cyclone statistics for the official 2018 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 2017. 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.
First snow of season histories are available for several thousand US weather stations -- NOAA's National Centers for Environmental Information has assembled an interactive map that allows the user to obtain the dates of the first measurable snowfall (0.1 inches or more) for several thousand weather stations across the United States (including Alaska) in the Global Historical Climatology Network that have at least 20 years of record. Clicking on a station location will provide not only the date of the first observed snowfall at that location, but the amount of this first snow and the first year of observation for that station. [NOAA Climate.gov News]
"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 evening hours of Friday, 21 December 2018) 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 late night hours of 2 January 2019), 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 2018 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 October 2018 was 1.55 Fahrenheit degrees above the 20th century average (1901-2000) for the month. Therefore, last month's global combined temperature was the second highest October temperature since global temperature records began in 1880, trailing the record highest October global combined temperature that was set in 2015 by 0.23 Fahrenheit degrees. When considered separately, the monthly average temperature over the global oceans for October 2018 was 1.30 Fahrenheit degrees above average. The monthly average October temperature of the land surface was 2.23 Fahrenheit degrees above average. Thus, the October 2018 temperatures over both the ocean and land surfaces ranked second in their respective records behind the record warm October 2015.
When considering the combined land-ocean global temperature for the year to date (January-October 2018), this ten-month temperature was the fourth highest global temperature for the first ten months of any year since 1880. [NOAA/NCEI State of the Climate]
A global map of Selected Significant Climate Anomalies and Events for October 2017 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 2018 was the third smallest areal extent for any October since satellite-derived ice records began in 1979. The sea ice around Antarctica also was the fourth smallest October ice extent in the last 40 years.
The snow cover extent across North America in October 2018 was the second largest extent for October in 51 years of record. [NOAA/NCEI Global Snow & Ice]

CURRENT CLIMATE MONITORING

An international global greenhouse gas information system is advanced -- Two weeks ago, the World Meteorological Organization (WMO) hosted the first symposium and user summit of the Integrated Global Greenhouse Gas Information System (IG3IS) in Geneva, Switzerland. The aim of this three-day symposium was to bring together technical developers and key users from several different sectors to help inform and guide reductions in emissions of carbon dioxide and other heat trapping greenhouse gases driving climate change. IG3IS will help support the Paris Agreement on climate change. [World Meteorological Organization Media Centre News]

CLIMATE FORCING

Atmospheric greenhouse gas concentrations reach new record levels in 2017 -- The World Meteorological Organization (WMO) recently released its "WMO Greenhouse Gas Bulletin No. 14: The State of Greenhouse Gases in the Atmosphere Based on Global Observations through 2017." This report describes the state of the heat-absorbing atmospheric greenhouse gases for carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) based upon global observations through 2017. Carbon dioxide levels reached 405.5 parts per million (ppm) in 2017, a level not seen in 3-5 million years. In addition, concentrations of methane and nitrous oxide also rose, along with a resurgence of a potent greenhouse gas and ozone depleting substance called CFC-11, which is regulated under the Montreal Protocol. WMO foresees no sign of a reversal in these trends, which are driving long-term climate change, sea level rise, ocean acidification and more extreme weather. [World Meteorological Organization Media Centre]
An ENSO conference is held in Ecuador -- A staff member at NOAA's Climate Prediction Center recently posted a blog on the ClimateWatch Magazine describing her experiences attending the IV International Conference on El Niño Southern Oscillation (ENSO) during mid-October in Guayaquil, Ecuador along with approximately 130 scientists from around the world. She discussed some topics presented at the conference, including ENSO in a warmer climate; the reasons for ENSO complexity; and the difficulties in predicting ENSO. [NOAA Climate.gov News]

CLIMATE FORECASTS

Australian tropical cyclone season outlook issued -- Forecasters at the Australian Government's Bureau of Meteorology recently released an outlook for the upcoming 2018-19 Australian tropical cyclone season that typically begins in November and runs through April. These forecasters foresee a fewer number of tropical cyclones than average within each of the five regions that surround the continent. They base their outlook upon the status of ENSO over the preceding July to September, the sea surface temperatures in the tropical Pacific Ocean and a survey of the suite of international outlook models. Therefore, their outlook for a lower than average tropical cyclone season is based upon the possible development of El Niño in the tropical Pacific Ocean and near average ocean temperatures to the north and east of Australia. [Australian Bureau of Meteorology]
Wind forecasts are improved for the renewable energy industry -- NOAA and the U.S Department of Energy (DOE) have been conducting research designed to improve forecasts for wind energy firms by between 15 and 20 percent. In addition, these forecasts could improve wind forecasts across the entire nation. The NOAA-DOE research, identified as "Wind Forecast Improvement Project 2" (WFIP 2), examined the physics of wind in complex terrain in the Columbia River Gorge between Washington and Oregon, with numerous wind farms. WFIP 2 is leading to an increased understanding of physical processes such as stability, turbulence, and low-level jets that affect wind energy generation in regions of complex terrain, such as coastlines, mountains, and canyons. [NOAA Research News]

CLIMATE AND SOCIETY

United Nations climate change conference to convene -- The twenty-fourth session of the Conference of the Parties (COP 24) and the fourteenth session of the Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol (CMP 14) is set to convene next Sunday (2 December 2018) in Katowice, Poland and run through Friday, 14 December. The key objective of this Katowice Climate Change Conference is to adopt the implementation guidelines of the Paris Climate Change Agreement, namely to hold the global average temperature to as close as possible to 1.5 degrees Celsius. [United Nations Framework Convention on Climate Change COP 24]
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).

Historical Events:

26 November 1896...Snow and high winds hit the Northern Plains and the Upper Mississippi Valley, with a Thanksgiving Day blizzard across North Dakota. The storm was followed by a severe cold wave in the Upper Midwest. The temperature at Pokegama Dam plunged to 45 degrees below zero, which remains the lowest recorded November temperature in Minnesota. (David Ludlum)
27 November 1701...Anders Celsius, the astronomer who invented the Celsius thermometer scale, was born in Uppsala, Sweden. (National Weather Service files)
27 November 1912...Snow fell across northern Florida, marking one of the few times it has ever snowed there in November. (National Weather Service files)
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)

Return to RealTime Climate Portal