Near-real-time images are derived from gridded brightness temperatures (TBs) from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager/Sounder (SSMIS) passive microwave radiometer. The TBs are calculated for each 25 kilometer grid cell. An algorithm is applied to produce an estimate of melt or no melt present for each grid cell. The data, images, and graphs are produced daily.
The colored areas on the daily image map records those grid cells that indicate surface melt from the algorithm, as a binary determination (melt / no melt). The melt extent graph indicates what percent of the ice sheet area is mapped as having surface melt, again from the binary determination per grid cell, using the summed area of the melt grid cells divided by the total ice sheet area.
Learn more at the NSIDC Greenland Ice Sheet Today page. The data that is used to create the graph here doesn’t appear to be easily accessible. If you are interested and email may do the trick.
A recent Guardian article, Photograph lays bare reality of melting Greenland sea ice by Alison Rourke and Fiona Harvey (6/17/19) has an excellent photo of sled dogs appearing to walk on water. The article provides some context related to Greenland and ice.
Last week, NOAA issued its annual forecast, saying that the summer dead zone—an area near the sea floor where there is little or no dissolved oxygen—may be just shy of 8,000 square miles in 2019, nearly as large as the record-setting area that occurred in 2017. The ecological impacts of the Gulf dead zone spread through the economy.
The hypoxic or ‘dead’ zone:
This spring surge in runoff feeds an overgrowth of algae and other plant-like microbes (phytoplankton) that live in the coastal waters. The algae eventually die and sink to deeper layers of the Gulf, where they are decomposed by bacteria. Like human breathing, decomposition uses up oxygen. Under the right conditions, the bottom waters become severely depleted in oxygen, suffocating fish and other marine life that can’t escape.
Is this normal?
Sediment cores dug up from the ocean floor indicate that a large, yearly dead zone is not a natural phenomenon in the Gulf of Mexico. Microfossils in the sediment layers from the years 1700-1900 include species that cannot tolerate hypoxic (low oxygen) waters, which is a good sign that oxygen stress wasn’t a widespread problem before the twentieth century.
The article has other interesting maps but doesn’t provide the data in the graph. The data might be acquired with an email to LUMCON. The original NOAA post, NOAA forecasts very large ‘dead zone’ for Gulf of Mexico (6/12/19) has links to their water monitoring stations.
The NASA research feature Tropical Cyclones are Stalling More by Kasha Patel (6/619) reports on hurricanes that stall for two days or more near U.S. coasts (graph copied here).
In a study published on June 3, 2019, scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) showed that North Atlantic hurricanes have been moving slower and meandering more from their average trajectory over the past seven decades. The result has been storms that stall more frequently and linger for longer periods of time near the coast, leading to more rainfall over confined locations.
A climate connection?
“There is some evidence that those large-scale wind patterns are slowing down in the tropics, where Atlantic storms usually start,” said Hall. “The storms are not being pushed as hard by the current that moves them along. That’s a climate change signal.”
One projected effect of climate change is that air masses will move more slowly around the world. As global temperatures rise, the Arctic is warming faster than the tropics—a phenomenon called Arctic amplification. As temperature differences between the tropics and high latitudes decrease over time, so will the difference in air pressure, leading to a reduction in winds.
The study linked to in the first quote has links to data and that study may be useful as classroom material.
U.S. net natural gas exports in February 2019 totaled 4.6 billion cubic feet per day (Bcf/d), marking 13 consecutive months in which U.S. natural gas exports exceeded imports. The United States exports natural gas by pipeline to both Canada and Mexico and increasingly exports liquefied natural gas (LNG) to several other countries.
Note the units, that is 4.6 billion cubic feet per day. The eia has links to the data.
In a related post How much coal does the U.S. export? this question was posed: If a country removes fossil fuels from the ground, how complicit are they in the CO2 emissions of those fuels even if they aren’t the ones burning it?
While U.S. coal consumption has generally declined since its 2008 peak, EIA expects that U.S. coal exports reached 116 million short tons (MMst) in 2018, the highest level in five years, based on foreign trade data collected by the U.S. Census Bureau. Exports of coal from the United States have increased since 2016 as international prices have made it more economic for U.S. producers to sell coal overseas.
While coal production in the U.S. has been on the decline (2014: 1,000,048,758 short tons; 2015: 896,940,563; 2016: 728,364,498; 2017:774,609,357 ) along with consumption, exports have been increasing. This raises philosophical questions. U.S. coal CO2 emissions have gone down due to burning less coal, but should U.S. CO2 emissions include U.S. coal burned in other countries? If a country removes fossil fuels from the ground, how complicit are they in the CO2 emissions of those fuels even if they aren’t the ones burning it?
The EIA article includes links to the data such as the Annual Coal Report page.
Monthly average sea surface temperatures in the Southern Ocean around Antarctica from 1850–2017, based on NOAA’s ERSSTv5 data set. Analysis by Climate Reanalyzer, University of Maine Climate Change Institute.
Thanks to thick ice, Antarctic elevation averages more than 6,000 feet (more than a mile above sea level). The very highest parts of the ice sheet, near the center of East Antarctica, rival the height of its tallest mountains, at nearly 13,500 feet.
Antarctica’s interior gets so little precipitation that it counts among the world’s driest deserts. Air masses reaching the high-elevation interior are usually stripped of moisture. The U.S. Antarctic Program reports that, continent-wide, Antarctica receives an average of roughly 2 inches of precipitation per year. (Phoenix, Arizona, gets about 7.5 inches of annual precipitation.)
Is Antarctica warming? It’s complicated:
The Intergovernmental Panel on Climate Change (IPCC) synthesis report published in 2014 found a warming trend over Antarctica, but expressed low confidence that the warming was caused by human activities. In the late twentieth century, the ozone hole and its effects on air circulation may have partly shielded the continent from the global warming influence of greenhouse gas emissions. Continued success in addressing the ozone hole, along with fossil fuel emissions, may cause Antarctic temperatures to rise more rapidly in future decades.
West of the Antarctic Peninsula, measurements dating back to the 1950s show a strong warming trend in the upper ocean: nearly 2.7°F. Meanwhile, waters of the Arctic Circumpolar Current (ACC), far below the surface, have warmed faster than the rest of the global ocean. Between depths of 1,000 and 3,000 feet, ACC temperatures rose by 0.11°F per decade between the 1960s and the 2000s. Between the 1980s and 2013, ACC temperatures at those depths rose by 0.16°F per decade.
What about ice melting?
In contrast with the Arctic—where climate change is amplified, and sea ice shows a clear declining trend over time—Antarctic sea ice does not show a significant overall trend in either the summer or the winter. One region, south and west of the Antarctic Peninsula, has shown a persistent decline, but this trend is small relative to the high variability of the other Antarctic sea ice regions. In 2015, sea ice experts concluded that the small gains in Antarctic sea ice in some seasons were not enough to cancel out Arctic losses, and so globally, sea ice was declining. That basic conclusion remains true in early 2019.
But what if all the ice on the continent melted?
If the entire Antarctic Ice Sheet were to melt at once, it would raise global sea level more than 180 feet. Outside of an epic natural disaster such as an asteroid slamming into Antarctica, that ice sheet isn’t going to melt entirely for centuries, but it will contribute to sea level rise over the next century. The question is: How much? The exact answer is elusive. The IPCC Fifth Assessment Report (AR5) states that the effect of Antarctic ice sheets on sea level rise over the coming century is a major unknown. Not only is the ice sheet melt rate challenging to measure precisely, but other events could accelerate sea level rise, and it’s hard to know when or even if those events will occur.
Read the article and get to know Antarctica. The is ample stats and QL classroom opportunities and graphs in the article.
Global CO2 emissions (gigatonnes, GtCO2) for all IAM runs in the SSP database. SSP no-climate-policy baseline scenarios are shown grey, while various mitigation targets are shown in colour. Bold lines indicate the subset of scenarios chosen as a focus for running CMIP6 climate model simulations. Chart produced for Carbon Brief by Glen Peters and Robbie Andrews from the Global Carbon Project.
The SSPs feature multiple baseline worlds because underlying factors, such as population, technological, and economic growth, could lead to very different future emissions and warming outcomes, even without climate policy.
They include: a world of sustainability-focused growth and equality (SSP1); a “middle of the road” world where trends broadly follow their historical patterns (SSP2); a fragmented world of “resurgent nationalism” (SSP3); a world of ever-increasing inequality (SSP4); and a world of rapid and unconstrained growth in economic output and energy use (SSP5).
The graph copied here is the 5th in a series of 8 as the article explains the modeling process. The article is particularly useful for any course that discusses the modeling process. Most of the charts are interactive and there is also an animated graphic. There are links to data sources that requires setting up an (free) account.
A number of agencies have reported that 2018 was the fourth hottest year on record. The report from NASA GIS, 2018 Fourth Warmest Year in Continued Warming Trend, According to NASA, NOAA (2/6/19) includes a short video showing the warming of the planet while including other facts. The report also includes the animated graph, copied here, with temperature trends from five different agencies.
Global temperatures in 2018 were 1.5 degrees Fahrenheit (0.83 degrees Celsius) warmer than the 1951 to 1980 mean, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. Globally, 2018’s temperatures rank behind those of 2016, 2017 and 2015. The past five years are, collectively, the warmest years in the modern record.
Time series of cumulative anomalies in SMB (blue), ice discharge (D, red), and total mass (M, purple) with error bars in billions of tons for (A) West Antarctica, (B) East Antarctica; (C) Antarctic Peninsula), and (D) Antarctica, with mean mass loss in billions of tons per year and an acceleration in billions of tons per year per decade for the time period 1979 to 2017.
The total mass loss from Antarctica increased from 40 ± 9 Gt/y in the 11-y time period 1979–1990 to 50 ± 14 Gt/y in 1989–2000, 166 ± 18 Gt/y in 1999–2009, and 252 ± 26 Gt/y in 2009–2017, that is, by a factor 6.
An interesting fact from the paper:
Antarctica contains an ice volume that translates into a sea-level equivalent (SLE) of 57.2 m.
