El Niño is Melting Glaciers, Flooding California

Recent research has suggested an increasingly important role between the pacific decadal oscillation (PDO) and the El Niño Southern Oscillation (ENSO) on natural phenomena around the globe, including glacial melt variability. These relationships are particularly strong when the PDO and ENSO are in-phase, as they are now.

One study by Bijeesh Kozhikkodan Veettilab, Nilceia Bianchinic, Ulisses Franz Bremerab, Éder Leandro Bayer Maierd, and Jefferson Cardia Simõesa looked at the formation of supraglacial lakes on the Baltoro Glacier in the Pakistani Himalayas from 1978 to 2014. Using a combination of various satellite images the study demonstrated that most of the lakes formed or expanded during the late 1970s to 2008, and that after 2008 the number and size of the lakes decreased.

They discovered that, “the formation and expansion of glacial lakes occurred during the warm regime of PDO, in particular in phase with the ENSO,” and that the shift in 2008 corresponded precisely with the onset of a cool phase of the PDO.

Image of the PDO phases.
PDO warm and cool phases from University of Alaska-Fairbanks Physics Department

The PDO is primarily a sea surface temperature phenomenon that oscillates in the Pacific Ocean, usually switching from a warm or positive phase to a cool or negative phase every 20-30 years. In the positive phase the Eastern Pacific, along the West coast of the Americas is unusually warm, while the Western Pacific along the East coast of Asia is unusually cool. During the negative phase the opposite occurs.

The PDO is often described as a long lasting ENSO-like event. ENSO is what is commonly referred to as El Niño and La Niña, a sea surface temperature oscillation in the southern Pacific Ocean that is a strong predictor of precipitation anomalies, and therefore drought or flooding, around the globe.

Image of the ENSO phases.
ENSO warm and cool phases from University of Alaska-Fairbanks Physics Department

In fact, this summer we are seeing a strong El Niño, also known as a positive ENSO, corresponding with a strong, positive PDO.

Researchers have known or suspected since the early 20th century that El Niño brings strong rains along the United States’ west coast. However, we now know, thanks to the results of the study on the Baltoro Glacier, that the formation and expansion of glacial lakes in the Karakoram Himalayas also occurs during the warm phase of the PDO, in particular when it is in phase with ENSO.

What this means is that the same events that are the likely cause of recent heavy rains and storms hitting Southern California are also likely causing increased glacial melt in the Himalayas.

According to The Weather Chanel, “Los Angeles, San Diego and over a dozen other California cities set all-time rainfall records for the month of July.” In fact, a National Weather Service meteorologist described these recent rains as “super historic.”

Researchers are beginning to pay more attention to sea surface temperature in the Pacific Ocean, and around the globe, as we are realizing that they influence everything from strong storms in California to glacial melt in the Himalayas.

The PDO was only relatively recently discovered, found in 1997 due to its influence on Pacific Northwest salmon production. Understanding what scientists call teleconnections between these various natural phenomenon can help us better prepare ourselves for the volatile environment in which we live. Knowing ahead of time that when Southern California will have heavy storms, mountain villages in the Himalayas should be wary of glacial lake flooding, can help save time, money, and lives.

Roundup: Tidewater Glaciers, North Cascades, Antarctic Bacterium

The Culprit for Greenland Ice Sheet Mass Loss

Source: Christine Zenino/Flickr
Greenland Ice Sheet. Source: Christine Zenino/Flickr

“Overall mass loss from the Greenland ice sheet nearly doubled during the early 2000s resulting in an increased contribution to sea-level rise, with this step-change being mainly attributed to the widespread frontal retreat and accompanying dynamic thinning of tidewater glaciers. Changes in glacier calving-front positions are easily derived from remotely sensed imagery and provide a record of dynamic change […] In this study multiple calving-front positions were derived for 199 Greenland marine-terminating outlet glaciers with width greater than 1 km using Landsat imagery for the 11-year period 2000–2010 in order to identify regional seasonal and inter-annual variations. Our results suggest several regions in the south and east of the ice sheet likely share controls on their dynamic changes, but no simple single control is apparent.”

Read more here.

Area Changes of North Cascades Glaciers

North Cascades Glaciers. Source: Sean Munson/Flickr
North Cascades Glaciers. Source: Sean Munson/Flickr

“We present an exhaustive spatial analysis using the geographic, geometric, and hypsometric characteristics of 742 North Cascades glaciers to evaluate changes in their areal extents over a half-century period. Our results indicate that, contrary to our initial expectations, glacier change throughout the study region cannot be explained readily by correlations in glacier location, size, or shape. Our statistical analyses of the changes observed indicate that geometric data from a large number of glaciers, as well as a surprisingly large amount of spatial change, are required for a credible statistical detection of glacier-length and area changes over a short (multidecadal) period of time.”

Read more here.


The Small Tough Organisms

Growth of cold-sensitive mutants on Antarctic Bacterial Media containing stressor. Source: D. Sengupta et al (2015).
Growth of cold-sensitive mutants on Antarctic Bacterial Media containing stressor. Source: D. Sengupta et al (2015).

“A population of cold-tolerant Antarctic bacteria was screened for their ability to tolerate other environmental stress factors. Besides low temperature, they were predominantly found to be tolerant to alkali. Attempt was also made to postulate a genetic basis of their multistress-tolerance […] A number of multistress-sensitive mutants were isolated. The mutated gene in one of the mutants sensitive to low temperature, acid and alkali was found to encode citrate synthase. Possible role of citrate synthase in conferring multistress-tolerance was postulated.”

Read more here.