DataStreme ECS WEEK TWELVE: 18-22 April 2016

ITEMS OF INTEREST

• National Park Week -- The US Department of the Interior's National Park Service has designated this week (16-24 April 2016) as National Park Week. A fee waiver will cover entrance and commercial tour fees in many of the national parks and monuments administered by the Park Service, which will celebrate its 100th anniversary on 25 August 2016. [National Park Service Fee Free Days]
  [Editor's Note: One of the National Park's jewels in the estimation of this reporter is Grand Teton National Park in northwestern Wyoming that is detailed by a ground photograph and satellite imagery in the NASA Earth Observatory EJH]
• Celebrate Earth Day --This Friday (22 April 2016) marks the 46th Earth Day, first proposed by the late Senator Gaylord Nelson of Wisconsin in 1970 as a teach-in to heighten awareness of the environment. The Nelson Institute for Environmental Studies at the University of Wisconsin-Madison has posted a website called "Gaylord Nelson and Earth Day: The Making of the Modern Environmental Movement" that highlights Senator Nelson and his idea became Earth Day. Several governmental websites provides links to various activities and resources planned for this week, including a website maintained by the US Environmental Protection Agency (EPA). NASA also provides a list of live public events and online activities on 21 and 22 April designed to celebrate Earth Day, including a Earth Day #24Seven Social Media event.
  On this Earth Day, the US, China and nearly 120 other nations are expected to sign the historic "Paris Agreement," an agreement drafted last December that deals with mitigation of the emissions of greenhouse gases.
• 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 Climatic Data Center (NCDC). Scientists at NCDC 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.

CURRENT CLIMATE STATUS

• March 2016 weather and climate for the nation reviewed -- Scientists at the NOAA National Centers for Environmental Information (NCEI) recently reported on their analysis of preliminary weather data collected during the month of March 2016. When averaged across the contiguous United States, the monthly temperature for March 2016 was 47.5 degrees Fahrenheit, which was 6.0 Fahrenheit degrees above the 20th-century (1901-2000) average. Therefore, this past month was the fourth warmest March since a comprehensive climate network began in 1895. All of the 48 contiguous states experienced above to much above average statewide temperatures in March, nearly half the states reporting temperatures that were in the top ten in the 122-year period of record. The average maximum (or daytime) temperature for March across the "lower 48" was the fourth highest on record, while the average minimum (or nighttime) temperature was also the fourth highest.
  Alaska reported its sixth warmest March in their 92-year period of record, with a monthly average temperature that was 7.8 Fahrenheit degrees above the long-term average.
  The average precipitation across the contiguous US for March 2016 was 2.89 inches, which was 0.38 inches above the 20th-century average, making the month the 26th wettest March since 1895. As many as 16 states along the West Coast, the Gulf Coast and the Midwest had statewide precipitation totals that were above to much above average. States that had March precipitation totals ranking in the top ten for their respective state histories included Washington, Texas, Louisiana, Arkansas, Mississippi, Wisconsin and Michigan. Both Wisconsin and Louisiana had their second western March on record. On the other hand, states across the Southwest and along the Atlantic Seaboard experienced below to much below average March precipitation. New Mexico reported its driest month on record, with a statewide precipitation total of only eight percent of average.
  Data analyzed by the Rutgers Global Snow Lab indicate the March snow cover extent across the contiguous US was the second smallest areal extent for the 50-year period of record across the 48 contiguous states. [State of the Climate NOAA/NCEI]
  NOTE: A description is provided of the climatological rankings employed by NCEI for their monthly and seasonal maps. [NOAA/NCDC]
  A blog written by Derek Arndt, Chief of the Climate Monitoring Branch at NOAA's NCEI, represents a narrative of the weather and climate across the nation during the month of March 2016. [NOAA Climate.gov News]
• March national drought report -- The National Centers for Environmental Information has posted its March 2016 drought report online. Using the Palmer Drought Severity Index, approximately three percent of the contiguous United States experienced severe to extreme drought conditions at the end of March, while approximately nine percent of the nation had severely to extremely wet conditions at that time.
• California's Sierra 2016 snowpack larger than last year's -- Comparison of true color images made of the central and southern Sierras in California and Nevada from the MODIS sensor on NASA's Aqua satellite at the end of March 2015 and at the start of April 2016 reveals marked differences in the snowpack on the Sierras between the two seasons. Although the extent of this year's snowpack seen by satellite is much larger than last year, traditional snow course measurements indicate snow cover is only 87 percent of the long-term average. [NASA Earth Observatory]
• Greenland ice melt season has a record early start-- Scientists with the Danish Meteorological Institute recently reported that Greenland's massive ice sheet has begun its annual summer melt earlier than ever in recorded history as nearly 12 percent of Greenland's ice sheet, which is roughly the size of Alaska, experienced some melting last week. Previous earliest ice melt commencement dates have occurred in May. The scientists are concerned about this sign of early melting since the Greenland ice sheet represents the second-biggest potential ice-melt contributor to sea-level rise, following behind Antarctica's ice sheet. [CNN]
• Ice caps on Canada's Ellesmere Island seen to shrink in size -- The Director of the National Snow and Ice Data Center (NSIDC) at the University of Colorado-Boulder recently reported on the disappearance of two ice caps on Ellesmere Island in Nunavut, Canada over the last 57 years, using an animation that shows the ice shrinkage from maps of ice extent made in 1959, 2001, 2014 and 2015. [NOAA Climate.gov News]
• Icebergs seen to calve from Antarctic ice shelf -- An image made by the MODIS sensor on NASA's Terra satellite nearly two weeks ago shows two large icebergs that broke from Antarctica's Nansen Ice Shelf and left to float into the Southern Ocean that surrounds the Antarctic continent. [NASA Earth Observatory]
• Waiting for a classic phenological event in Alaska -- For the last 99 years the annual breakup of the ice on Alaska's Tanana River at the community of Nenana has drawn widespread attention due to the wagering in the Nenana River Ice Classic competition. A plot of the time series of the annual ice out dates since 1917 made by the National Snow and Ice Data Center last year shows interannual (year-to-year) variability in ice-out dates associated with changes in winter temperature and snowfall accumulation in interior Alaska are superimposed upon the nearly century long trend in earlier ice out-dates associated with long-term climate changes. [NOAA Climate.gov News] NOTE: A webcam provides a continuously updated view of the tripod on the Nenana River that is used to officially determine the winner of the Nenana Ice Classic.
• The 2015 hurricane season reviewed -- The 2015 hurricane season in the North Atlantic along with the eastern and central North Pacific is reviewed and compared to the more than 150 years of record keeping in the North Atlantic and the 40 years in the eastern North Pacific. [AMS DataStreme Atmosphere]

CURRENT CLIMATE MONITORING

• Nation's agricultural forecasts get a boost from NOAA's satellite data -- For as many as four decades, the Joint Agricultural Weather Facility operated jointly by NOAA and the US Department of Agriculture (USDA) has been assisting farmers and ranchers prepare for and respond to changing weather and climate conditions through the publication of the Weekly Weather and Crop Bulletin and a variety of agricultural forecasts. The Bulletin along with the forecasts utilizes data collected by NOAA's fleet of polar and geosynchronous satellites. [NOAA NESDIS News]
• Monitoring carbon emissions from Alaskan permafrost -- NASA scientists have been measuring the amount of carbon dioxide and methane gas that are being emitted from the permafrost in northern Alaska over the last four summers as part of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE). These researchers collected the data from sensors placed on a C-23 Sherpa aircraft from NASA's Wallops Flight Facility. They found large bursts of methane released in spring as the tundra thaws northward. [NASA Earth Observatory]

CLIMATE FORECASTS

• El Niño Advisory continues and La Niña Watch is issued -- Forecasters with NOAA's Climate Prediction Center (CPC) recently announced that they are continuing their El Niño Advisory for the current El Niño event due to the positive sea surface temperature (SST) anomalies across most of the equatorial Pacific that signify warmer than average ocean waters. However, these SST anomalies have been decreasing in magnitude across the eastern equatorial Pacific. In addition, the forecasters are issuing a La Niña watch as they envision a 50 percent chance that a La Niña event would develop by during the second half of 2016 autumn, which would follow the anticipated transition from the El Niño event to ENSO-neutral conditions during late spring or early summer in the Northern Hemisphere. [NOAA Climate Prediction Center]
  An ENSO blog was written by a CPC researcher that details the thinking that went into the preparation of the recently released April El Niño forecast. Discussion is also made of the possible La Niña that could develop. [NOAA Climate.gov News]
• Early hurricane season forecast -- Last week, the hurricane forecast team from Colorado State University headed by Dr. Phil Klotzbach released its April forecast of the 2016 North Atlantic hurricane season that officially begins on 1 June 2016. The team, which includes Professor William Gray, foresee that this upcoming hurricane season should have approximately average tropical cyclone activity. Although Hurricane Alex formed in January 2016, their initial April forecast envisions twelve named tropical cyclones following Hurricane Alex, along with five additional hurricanes. Of these hurricanes, the forecasters foresee two major hurricanes. A near-average probability is anticipated for major hurricanes making landfall along the United States coastline and in the Caribbean. The team bases their outlook on the continued weakening of the current El Niño event this late spring in the Northern Hemisphere, followed by a transition to ENSO-neutral conditions or possibly La Niña conditions by the peak of the Atlantic hurricane season in early to mid September. They are also considering the relatively warm waters of the tropical Atlantic along with a quite cold far North Atlantic, which is indicative of a of a negative phase of the Atlantic Multi-Decadal Oscillation.
  In mid-May, forecasters with NOAA's Climate Prediction Center (CPC) also should provide their outlook for the 2016 Atlantic hurricane season. [The Tropical Meteorology Project]
• Sea surface temperature patterns could help predict tornado outbreaks with long lead time -- A scientist with NOAA's Atlantic Oceanographic and Meteorological Laboratory and colleagues at the University of Miami, NOAA's Geophysical Fluid Dynamics Laboratory and NOAA's Climate Prediction Center have found a high probability of tornado outbreaks occurring in distinct regions across the nation for each of four dominant spring patterns of sea surface temperature associated with El Niño and La Niña variations. [NOAA News]

CLIMATE AND SOCIETY

• Accomplishments of NOAA Education in 2015 noted -- NOAA's Office of Education recently released its "Accomplishments Report for Fiscal Year 2015," which details a variety of preK-12 education achievements through the year. As required by the America COMPETES Act, this report identifies NOAA's Education strategic plan that identifies five goals: Science-Informed Society; Conservation and Stewardship; Safety and Preparedness; Future Workforce; and Organizational Excellence. [NOAA Education]
• 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

1. 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.
2. 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:

• 18 April 2004...A record 182 consecutive days of no measurable precipitation began in San Diego, CA on this date, which ended on 17 October 2004 with 0.09 inches of rain. This new record broke the 181-day record set the previous year. Interestingly, the rain that followed the more recent dry spell resulted in October 2004 becoming San Diego's wettest month on record (4.98 inches). (Accord Weather Guide Calendar)
• 19 April 1973...Glenrock, WY received 41 inches of snow in just 24 hours, and a storm total of 58 inches, to establish two state records. (18th-20th) (David Ludlum) (The Weather Channel)
• 20 April 1880...Sacramento, CA had its heaviest 24-hour rainfall when 7.24 inches fell. (Intellicast)
• 20 April 1901...A spring storm produced unusually heavy snow in northeast Ohio. Warren received 35.5 inches in thirty-six hours, and 28 inches fell at Green Hill. Akron established April records of 15.6 inches in 24 hours, and 26.6 inches for the month. Pittsburgh, PA established April records of 12.7 inches in 24 hours, and 13.5 inches for the month. (David Ludlum) (The Weather Channel)
• 20 April 1984...A temperature of 106 degrees in Del Rio, TX set a new record high for April. (Intellicast)
• 20 April 1987...Fifty-two cities in the central and eastern U.S. reported new record high temperatures for the date. The high of 92 degrees at Memphis, TN was a record for April, and the high of 94 degrees at Little Rock, AR equaled their April record. (The National Weather Summary)
• 20 April 1989...Hot weather spread from the southwestern U.S. into the Great Plains Region. Twenty-three cities reported new record high temperatures for the date. The afternoon high of 104 degrees at Tucson, AZ was an April record, and highs of 87 degrees at Provo, UT, 90 at Pueblo, CO, and 85 at Salt Lake City, UT, equaled April records. (The National Weather Summary)
• 21 April 1989...The temperature at Las Animas, CO soared to 100 degrees to establish a state record for April. Twenty-two cities in the central and southwestern U.S. reported record high temperatures for the date. Eight cities equaled or exceeded previous April records. Tucson, AZ experienced its fourth consecutive day of record heat with an afternoon high of 104 degrees, bringing the total number of days during the month of April 1989 to 11 when record high values had either been matched or broken. (The Weather Channel) (The National Weather Summary) (Intellicast)
• 21 April 1992...Two inches of snow fell at International Falls, MN, bringing the winter season snowfall to 106.7 inches and setting a new all-time record for the city. The old record was 104.7 inches set back in the 1988-89 winter season. (Intellicast) Editor's Note: The seasonal snowfall accumulation for the 2008-09 winter reached a record 125.6 inches. EJH
• 22 April 2003...Tropical Storm Ana formed in the southwestern North Atlantic Ocean, becoming the first Atlantic tropical storm (since records began in 1871) to form during the month April. Maximum sustained winds reached 50 mph. (The Weather Doctor)
• 23 April 1910...The temperature at the Civic Center in Los Angeles, CA hit 100 degrees to establish an April record for the city. (The Weather Channel)
• 23 April 1989...Salina, KS was the hot spot in the nation with a high of 105 degrees. The high of 105 degrees established an April record for the state of Kansas. A total of eighteen cities in the central U.S. reported record high temperatures for the date. (The National Weather Summary) (Storm Data) (The Weather Channel)
• 23 April 1996...One inch of snow on this day at Cleveland, OH brought its seasonal snowfall to 101.1 inches -- the city snowiest winter ever. The old record was 100.5 inches set in 1981-82. (Intellicast)
• 24 April 2003...The temperature at Juneau, AK soared to a maximum of 70 degrees, the earliest occurrence of a 70-degree reading for the period of record in Alaska's capital city. (The Weather Doctor)

Return to DataStreme ECS RealTime Climate Portal

Prepared by Edward J. Hopkins, Ph.D., email hopkins@aos.wisc.edu
© Copyright, 2016, The American Meteorological Society.