A devastating tropical cyclone swept across Myanmar (formerly Burma) killing as many as 22,000 people according to government sources. Tropical Cyclone Nargis slammed into the south-east Asian country on Saturday with wind speeds reaching 190km/h (120mph).

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Myanmar shares borders with China on the north, Laos on the east, Thailand on the southeast, Bangladesh on the west, and India on the northwest, with the Bay of Bengal to the southwest (Wikipedia). It has a tropical monsoon climate with rainy hot summers (”southwest monsoon”) and mild, less humid winters (”northeast monsoon”). Flooding and landslides are common during the rainy season. Deforestation has compounded these problems.

The impact of Cyclone Nargis can be seen the photos above. This pair of images from the Moderate Resolution Imaging Spectroradiometer (MODIS) use a combination of visible and infrared light to make features discernable. Water is blue or nearly black, vegetation is bright green, bare ground is tan, and clouds are white or light blue. Rivers, fallow farm fields and the brilliantly green vegetation is well-defined in the April 15 picture (top). Flooding of the coastal plain shown in the May 5 image (bottom) appears to have hit the fallow agriculture lands close to the Gulf of Martaban especially hard. For more see: Cyclone Nargis Floods Myanmar (Burma)

TPE Links: Hurricanes; Tropical Monsoon climate

An enhanced greenhouse effect caused by human activities will upset the radiation balance of the earth system creating a variety of changes in the geography of planet Earth, the most notable being air temperature. Temperature trends over the past 100-plus years clearly indicate rising temperatures on all continents and over the oceans.

The arctic regions appear to be impacted the most. Observations of mean annual surface air temperature over the past 50 years has increased 3.6^oF to 5.4°F in Alaska and Siberia and decreased by 1.8°F over southern Greenland. Mean annual surface air temperature over the Arctic region (north of 60° latitude) is projected to increase 3.6°F by 2050 and 8°F by 2100.

Discovery News took a look at the effects of global warming on Alaska that are presently occurring.

TPE Links: Future Geographies: Global Warming and Regional Temperature Patterns

Residents of southeast Illinois were surprised early Thursday morning when the ground beneath them shook from a 5.2 earthquake centered 6 miles from West Salem, Illinois. Skyscrapers shook in Chicago and was felt as in Cincinnati and Milwaukee.

The quake occurred in the Illinois basin-Ozark dome region that covers parts of Indiana, Kentucky, Illinois, Missouri, and Arkansas and stretches from Indianapolis and St. Louis to Memphis. Less active than the more famous New Madrid seismic zone, this region is subject to moderately damaging earthquakes every decade or two. Smaller earthquakes are recorded more often.

For more about this earthquake see the summary at the USGS Earthquake Hazards Program site, or listen to this USGS CoreCast

TPE Links: Faulting; Geographic Patterns of Faults and Earthquakes

Image courtesy USGS

Jet streams are a zone of high velocity winds in the upper troposphere. They play a crucial role in the development and movement of weather systems across the earth. New research seems to indicate that global warming may be altering these very important winds. Cristina Archer and Ken Caldeira of the Carnegie Institution’s Department of Global Ecology examined jet stream conditions in both northern and southern hemispheres over a 23-year period from 1979 to 2001.They found that the jet streams in both hemispheres have risen in altitude and shifted toward the poles. The jet stream in the northern hemisphere has also weakened. These changes fit predictions from global warming climate models and have drastic implications for the frequency and intensity of storms systems and patterns of precipitation that will reverberate through the earth system.

For more see: “Changing Jet Streams May Alter Paths of Storms and Hurricanes“

TPE Links: Upper-tropospheric patterns of winds and pressure; Surface Cyclones and Jet Streams

Once again, conditions are right for serious spring flooding along major rivers like the Mississippi. Late winter and early spring precipitation, combined with the melting of a deep snowpack in the upper Midwest is sending rivers over their banks, inundating the surrounding terrain. Like the historic flood of 1993, this year could result in much damage as people continue to occupy flood-prone areas like floodplains.

Flooplains are flat areas that border a stream that are covered with water when a channel can no longer contain its flow. Levees are used to contain flood waters, yet they may do more harm than good. Levees cause water to rise higher, rather than allowing it to spread out onto the the surrounding floodplain. Levees also encourage development on floodplains, giving inhabitants a false sense of security (see ScienceDaily for more).

You can keep track of this year’s flooding by visiting the USGS’s WaterWatch Map of Flood and High Flow Conditions and Daily Stream Flow Conditions in real-time.

House Colliding with Bridge (March 200

TPE Link: Floods and Flooding

Wired magazine recently published an article alerting the public to the start of a new sunspot cycle, and this one appears to be a doozy.

Sunspots are dark spots of cooler temperature on the surface of the Sun (the photosphere). They can be as large as 50,000 miles in diameter, expanding and contracting in size as they move across the surface of the Sun. Sunspot cycles usually last for about 11 years. Sunspots have been monitored since Galileo’s time. Solar flares emerge from the Sun’s surface around sunspots. These violent releases of energy often wreak havoc on human activities and infrastructure when they reach Earth.

Peak sunspot activity for the coming cycle is to occur in about four years. The forecast for 2012 is disruption of GPS satellite signals, possibility for low-flying satellites being knocked out of their orbit, and disruption of radio signals, especially aircraft communications in northerly latitudes.

TPE Links: The Sun

Image courtesy NASA

More signs of global warming appeared this week as a huge portion of the Wilkins Ice Shelf broke away from the Antarctic Peninsula. Scientists are worried that the rest of the ice shelf may collapse as it is presently being supported by a thin strip of ice hanging between two islands. 

 TPE Link: Climate Change: Evidence for Global Warming

A new UN Environment Programme (UNEP) report states that the average rate of melting more than doubled in close to 30 glaciers in 9 mountain ranges between 2004-2005 ad 205-2006 (see Science Daily “Glaciers Are Melting Faster Than Expected, UN Reports). The accelerated rate of melting is particularly troubling for the millions of people dependent on glacier melt water drinking water, agriculture, industry and power. 

TPE Link: Climate Change: Global Warming - Evidence from Glaciers.

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For those who missed it, NPR’s continuing coverage of Climate Connections reported on how global warming’s impact on rainfall is affecting power generation in Costa Rica, who is trying to be the first carbon-neutral country (See “Rainfall Shortages Threaten Costa Rica Power” ). 

TPE Link: Global Patterns of Precipitation

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 The National Weather Service’s Flood Safety Awareness week is March 17 -21, 2008. Though flooding is a hazard in the United States in all months, the spring an be particularly troublesome when deep snowpacks melt too quickly. Impeded by frozen ground, water runoffs swelling rivers beyond their capacity (See “Flood Safety Awareness”) .

TPE Link: Floods and Flooding

Arctic sea ice appears to be disappearing at a faster rate than previously expected. 2007 Arctic summer sea ice was at it’s lowest extent on record - 25 % below the previous record set in 2005. It’s no surprise the UK’s Hadley Centre and University of East Anglia announced that this year is the seventh warmest on record for the globe and second warmest for the Northern hemisphere. At the recent American Geophysical Union meeting in San Francisco, renown climate scientist James Hansen suggested that the earth has already crossed several climate change “tipping points”. Hanson believes that today’s levels of greenhouse gases will cause additional large and rapid changes. Current levels of greenhouse gases is enough to cause Arctic sea ice and the Greenland ice cap to melt away.

At the same meeting Professor Wieslaw Maslowski suggested that previous projections had underestimated the processes that now drive sea ice loss. “The Arctic is screaming,” Mark Serreze, a senior scientist at the National Snow and Ice Data Center (Boulder, Colorado) described of the change occurring in the Arctic. Professor Maslowski and his team estimate that the Arctic sea could be ice free by 2013. Enough melt occurred this year to open the fabled sea route The Northwest Passage - a short cut from Europe to Asia through the Canadian Arctic. Circumstances for the Arctic seem dire as as some think this “canary” in the proverbial “coal mine” is, or has died .

TPE Links: Climate Change: Global warming - Evidence from the Oceans; Natural Systems

Resources for this posting:
Global Warming “Tipping Points” Reached, Scientist Says. National Geographic News
‘The Arctic is Screaming’, expert says. Indianapolis Star
2007 data confirms warming trend. BBC News
Arctic Summer ice-free ‘by 2013′. BBC
Warming ‘opens Northwest Passage’. BBC

Image courtesy NASA (Source)

The U.S. Geological Survey (USGS), the British Antarctic Survey (BAS), and the National Aeronautics and Space Administration (NASA), with funding from the National Science Foundation (NSF), have teamed to create the LANDSAT Image Mosaic of Antarctica (LIMA). Lima is the first major out come of the International Polar Year (IPY 2007-2008). LIMA supports research and encourages new projects that help the general public visualize environmental change in Antarctic.

LIMA was created from more than 1,000 Landsat ETM+ scenes. Researchers and the public alike have free access to LIMA and all component Landsat scenes. With the Web viewer one can pan across the continent or zoom in to see amazingly detailed Natural-Color images.

Visit LIMA

TPE Link: Aerial Photographs and Remote Sensing