WEEKLY CLIMATE NEWS

DataStreme ECS WEEK THREE: 23-27 September 2013

ITEMS OF INTEREST

Notice the sunrise-sunset times at the equinox -- The autumnal equinox, which marks the commencement of astronomical fall , occurred this past Sunday afternoon (officially at 2044Z on 22 September 2013 or 4:44 PM EDT or 3:44 PM CDT, etc.). If you checked the sunrise and sunset times in your local newspaper or from the climate page at your local National Weather Service Office, you would probably find that not until the midpoint of this coming week will the length of time when the Sun is above the local horizon would be precisely 12 hours at most locations. However; the length of night will exceed that of the length of daylight by the end of the week. As discussed in this week's Supplemental Information…In Greater Depth, the effects of atmospheric refraction (bending of light rays by the varying density of the atmosphere) along with a relatively large diameter of the sun contribute to several additional minutes that the sun appears above the horizon at sunrise and sunset.
Monitoring the seasonal motions of the sun -- If you would like more background information concerning how the sun appears to across your local sky, along with the times of local sunrise and local sunset, for your hometown on any day throughout year, please read this week's Supplemental Information…In Greater Depth.
"ClimateChangeLive" distance learning adventure webinar scheduled for this week -- The first in a series of seven webinars will be available between 7:30 and 9:00 PM this coming Wednesday, 25 September 2013. The series of webinars is designed to raise awareness and understanding of climate change science and is aligned to national science education standards. The collection of science-based, climate education resources and programs have been gathered from at least 19 federal agency and NGO partners that include the US Forest Service, NOAA, the US Fish and Wildlife Service. The first webinar scheduled for this Wednesday is "Bring Your Class Along on a ClimateChangeLIVE Distance Learning Adventure!" Check http://climatechangelive.org/ for registration details.
Informational resources made available for FIRST® LEGO® League Nature's Fury^SM Challenge -- NOAA Education Resources has provided a list of educational resources that can be used by FIRST Lego League teams and others in planning for the "2012 FLL Nature's Fury^SM Challenge" Project. [NOAA Education Resources ]
Fall coloration -- By mid-September, deciduous trees begin to turn color across the nation, starting first across the higher elevations of New England and the Rocky Mountains, followed quickly across sections of the upper Midwest. During autumn, the peak in fall color progresses southward and toward lower elevations. Some locales hold events in an effort to welcome tourists who come as "leaf peepers." The U.S. Department of Agriculture maintains a telephone hotline number and U.S. Forest Service Fall Color Hotline Web page containing fall foliage status updates for National Forests across the continental United States. Additional information is also available through the tourism bureaus of the various states; links to some of these state sites are available from this Forest Service web page.
[Editor's Note: An interesting explanation of fall coloration can be found in The Chemistry of Autumn Colors from "Science is Fun in the Lab of Shakhashiri" from a popular chemistry educator at the University of Wisconsin-Madison. EJH]

CURRENT CLIMATE STATUS

Review of August 2013 (and seasonal) weather and climate for the globe reviewed -- Preliminary data analyzed by scientists at NOAA's National Climatic Data Center (NCDC) indicated that the global combined land and ocean average surface temperature for August 2013 was 61.2 degrees Fahrenheit, which tied August 2005 for the fourth highest August monthly temperature since a sufficiently dense network of global temperature records began in 1880. The globally averaged August 2013 temperature was approximately 1.1 Fahrenheit degree above the 20th-century average (1901-2000) for the month. When considered separately, the monthly temperature of the ocean surface was 1.03 Fahrenheit degrees above the 20th-century average, essentially tying it with ocean temperatures in 1998, 2003, 2005, and 2009 month for the record highest August temperature. On the other hand, the land surface surface temperature for this recently concluded month was the eleventh highest August temperature on record, with a temperature that was approximately 1.39 Fahrenheit degrees above the long-term average. The researchers also noted that the global land and ocean average temperature for the three-months of June, July and August (meteorological summer in the Northern Hemisphere) 2013 tied the corresponding months of 2009 was the fifth highest for that three-month period since 1880. The June-August 2013 temperature for the ocean was fifth highest while the corresponding land temperature for the three months was the seventh highest for any boreal summer in the last 134 years. [NOAA/NCDC State of the Climate]
According to data provided by the National Snow and Ice Data Center, the average August Arctic sea ice extent was approximately 15.6 percent below the 1981–2010 average, making it the sixth smallest August Arctic sea ice extent since satellite records began in 1979. However, the August 2013 Arctic sea ice extent was larger than the record low August extent of 2012. Conversely, the August Antarctic sea ice extent was the largest August extent on record, surpassing the previous record of August 2010.
Note: As of mid-September 2013, the Arctic sea ice extent remained the sixth smallest on record, at a time when the minimum ice extend occurs during the summer melt season. [NASA's Earth Science News Team]

CURRENT CLIMATE MONITORING

An All-Hazards Monitor -- This Web portal provides the user information from NOAA on current environmental events that may pose as hazards such as tropical weather, fire weather, marine weather, severe weather, drought and floods. [ NOAAWatch]

CLIMATE FORECASTS

New Seasonal Climate Outlooks for the remainder of 2013 issued -- Near the end of last week, forecasters at the NOAA Climate Prediction Center (CPC) released their new national Three-Month (Seasonal) Climate Outlooks for October through December 2013, corresponding to the last two months of the meteorological autumn season (in the Northern Hemisphere) and the first two month of meteorological winter. Specific details of their outlooks include:
- Temperature and precipitation outlooks -- According to their temperature outlook, most of the coterminous United States to the west of the Continental Divide and the southern high Plains should experience a high chance of above average temperatures for these three upcoming months, with the greatest probability of such an occurrence to be found across the Great Basin, the southern Rockies and west Texas. Chances of above average temperatures for the last three months of 2013 also would be better than average across the New England States. situated across the Intermountain West and the southern Sierra Nevada Range in California along with the Rockies and southern high Plains. The outlook indicates that the remainder of the nation extending from the Plains to the Atlantic Seaboard would have nearly equal chances of warmer or cooler than normal conditions.
  Their precipitation outlook calls for most of the coterminous states to have essentially equal chances of below and above average precipitation for October through December, 2013. Only a relatively small area across the interior Northwest, especially over the northern Rockies and the adjacent high Plains, had better than even chances of above average rainfall totals for these last three months of the year.
  A summary of the prognostic discussion of the 3-month outlook for non-technical users is available from CPC. These forecasts were based in part that assuming that the current ENSO-neutral conditions (ENSO = El Niño/Southern Oscillation) should continue through the remainder of the year, where neither El Niño nor La Niña conditions should prevail. A description is also provided as how to read these 3-class, 3-month Outlook maps.
- Seasonal Drought Outlook released -- The forecasters at NOAA's Climate Prediction Center also released their US Seasonal Drought Outlook last week that would run from late-September through December 2013. Their outlook would call for persistence of extensive drought conditions across a large section of the nation extending from sections of the Mississippi Valley westward to the Pacific Coast. Only the northern tier of states running from western North Dakota to Washington would experience an improvement in drought conditions or would not have been under drought at the present. Other areas that could see at least some improvement in drought conditions during the rest of the year would include the coast of northern California and across sections of the Mid-South. Currently, much of the eastern third of the nation do not appear to be headed for drought conditions. Note: a Seasonal Drought Outlook Discussion is included describing the forecasters' confidence.
Current "stressed" watersheds may become the new normal -- Researchers from the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder and their colleagues from other institutions who made an analysis of surface water in 2103 watersheds across the continental United States report that nearly one in ten national watersheds is "stressed," with demand for water exceeding natural supply. They warn that the lowest water flow seasons of recent years, which place greater stress on rivers, streams, and sectors that use their waters, are likely to become typical as climates continue to warm. [University of Colorado Boulder News]
Prediction of favorable weather for Winter 2014 Olympics by Russian meteorologist -- With the 2014 Winter Olympic Games to be held within six months (6-13 February 2014) at Sochi, the deputy director of the Russian government's Gidromettsentr weather agency is predicting near normal temperatures and snowy weather conditions in the Sochi region along the Black Sea and across the Caucasus. He believes these weather conditions would be more favorable to the outdoor venues than have been the case for the last several winter Olympics. However, organizers have begun storming snow in refrigerated reservoirs as a precaution. [RIANOVOSTI]

CLIMATE FORCING

Monitoring and assessing changes in extremes of midlatitude storms, winds and waves -- A new scientific assessment entitled "Monitoring and Understanding Changes in Extremes: Extratropical Storms, Winds, and Waves" will be published in the Bulletin of the American Meteorological Society that was prepared by a team of scientists of the changes in extreme extratropical storms, winds and ocean waves that affect the United States since the mid-20th century. In their assessment, they produced a diagram that provides a visualization of the "adequacy for detecting and understanding changes for classes of extremes." [NOAA National Climatic Data Center News]
Presence of undersea mountains provides an influence in climate prediction --Scientists from the United Kingdom and the United States have measured the mixing of ocean waters in the Southern Ocean so as to improve understanding of the mixing of deep and mid-depth oceans are mixed and ultimately, improve long-term climate projections. They used an inert chemical tracer released into the Southern Ocean to measure the mixing. They found that seawater mixes dramatically as to passes over undersea mountains in Drake Passage, the channel situated between South America's Cape Horn and the Antarctic continent. [University of Exeter News]
First map released detailing Iceland's glaciers and subglacier calderas --A map entitled "Map of the Glaciers of Iceland" was recently released showing for the first time all of Iceland's approximately 300 glaciers along with the subglacier volcanic calderas and their locations with respect to the glaciers. This map was produced by the Icelandic Meteorological Office, in collaboration with the US Geological Survey (USGS) and Iceland Geosurvey. Historical data along with coverage by aerial photographs and remote sensing satellite including NASA's Landsat and the French SPOT satellite were used to show changes in the areal extent of the glaciers over the last century. [USGS Newsroom]

CLIMATE AND IMPACTS ON HUMAN HEALTH

Estimating the global human toll due to fine particulate matter -- Scientists at the University of North Carolina and other institutions have used six atmospheric computer models to estimate the number of deaths worldwide that have been the result of air pollution commencing in 1851. They estimated that 2.1 million deaths have occurred worldwide each year as a direct result of a toxic type of outdoor air pollution known as (PM2.5) during the last 160 years. A map was generated from statistics generated by these computer models that estimate the average number of deaths per 1000 square kilometers per year due to air pollution. [NASA Earth Observatory]
Reducing air pollution leads to improved life expectancy -- A team of researchers has found that improvements in the air quality across the United States since 1990 have resulted in a 35 percent reduction in deaths and disability specifically attributable to air pollution. They found that dirty air impacted hospital admissions, mortality rates, and cardiovascular disease, including the risk of heart attacks. [Brigham Young University News]

CLIMATE AND THE BIOSPHERE

Alaskan crabs are not immune from effects of rapidly acidifying waters -- A story prepared for the Public Broadcasting System (PBS) NewsHour by The Seattle Times and the Pulitzer Center on Crisis Reporting reports that increasing ocean acidification caused by rising carbon emissions into the atmosphere has begun altering the chemistry of the North Pacific and the Bering Sea, which create trouble for Alaska's noted crab populations. The frigid waters of the Bering Sea are considered to be one of the world's most productive marine systems. [PBS NewsHour]

CLIMATE AND SOCIETY

Carbon pollution standards for new power plants proposed by EPA -- At the end of last week, the US Environmental Protection Agency (EPA) proposed Clean Air Act standards designed to achieve the first milestone of President Obama's Climate Action Plan by cutting carbon pollution from new power plants to combat climate change and improve public health, . Furthermore, EPA has initiated broad-based outreach and direct engagement with governmental agencies at state and local level, industry organized labor and other parties to establish carbon pollution standards for existing power plants to move toward a cleaner power sector. [EPA Newsroom]
Website for human dimensions of climate change -- An interagency effort within the US federal government that included NOAA, the Bureau of Land Management and the US Forest Service, has resulted in a website called HD.gov (for HumanDimensions.gov) that provides users, such as natural resource managers, with information on the human dimensions on a variety of topics of interest such as climate change. [HD.gov]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

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

23 September 1904...The temperature at Charlotteburg, NJ dipped to 23 degrees, the lowest reading of record for so early in the autumn for the state. (The Weather Channel)
24 September 1888...The earliest frost of record hit the southern states covering South Carolina, Georgia and northern Florida (Intellicast)
24 September 1926...The temperature at Riverside Ranger Station in Yellowstone Park dipped to nine degrees below zero, the lowest reading of record in the U.S. during September. (This record was broken by a 15 degree below zero reading at Big Piney, WY in September 1983.) Severe freezes were widespread over the northwestern U.S. causing great crop destruction. In Washington State, Spokane County experienced their earliest snow of record. Harney Branch Experiment Station in Oregon reported a temperature of 2 degrees above zero to establish a state record for the month of September. (David Ludlum) (The Weather Channel)
24-26 September 1950...A smoke pall from western Canada forest fires covered much of the eastern U.S. Daylight was reduced to nighttime darkness in parts of the Northeast. The color of the sun varied from pink to purple, blue, or lavender. Yellow to gray-tan was common. (24th-30th) On the 26th, residents of the northeastern U.S. observed a blue sun and a blue moon from the smoke. (David Ludlum) (The Weather Channel)
25 September 1939...A West Coast hurricane moved onshore south of Los Angeles bringing unprecedented rains along the southern coast of California. Nearly five and a half inches of rain drenched Los Angeles during a 24-hr period. The hurricane caused $2 million in damage, mostly to structures along the coast and to crops, and claimed 45 lives at sea. "El Cordonazo" produced 5.66 in. of rain at Los Angeles and 11.6 in. of rain at Mount Wilson, both records for the month of September. (David Ludlum) (The Weather Channel)
26 September 1963...San Diego, CA reached an all-time record high of 111 degrees. Los Angeles hit 109 degrees. (David Ludlum)
27 September 1816...A black frost over most of New England kills unripened corn in the north resulting in a year of famine. (David Ludlum)
27-28 September 1953...The strongest wind gust ever recorded during a hurricane was 175 mph at Chetumal, Mexico. (The Weather Doctor)
28 September 1893...Albuquerque, NM was soaked with 2.25 inches of rain, enough to establish a 24-hour record for that city. (The Weather Channel)
28 September 1986...Torrential rains and floods were responsible for South Africa's worst natural disaster in Natal. As much as 35 in. of rain fell between the 25^th and 29^th to the northeast of Empangen, resulting in 317 deaths and 163 people missing. Topsoil from some farms was completely washed away leaving only bedrock. (Accord Weather Calendar)

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