We grow up hearing about acid rain, but what about other forms of acidic precipitation — do they even exist? 
 
 One form, acid snow, certainly does exist. Acid snow is as natural as acid rain in our post-industrial revolution world and it poses an unusual threat. Let's delve into the properties of acid snow, along with its dangerous backlash when Spring comes and temperatures rise. 
 
 The top image is an altered form of an image by day-light on deviantART. 
 
 How is acidic precipitation created? 
 
 
 
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 Normal rain is already somewhat acidic, due to the absorption of carbon dioxide in the atmosphere. The carbon dioxide in the air becomes carbonic acid, a weak acid, leading to a pH of approximately 5.6 for most rainfall across the world. 
 
 Acid precipitation is created when industrial pollutants like sulfur oxide and nitrogen oxide react with water in the atmosphere. Upon reaction with water, nitric acid and sulfuric acid forms, and this decreases the pH of the ensuing precipitation. 
 
 Both sulfur oxide and nitrogen oxide are pollutants created in the process of fuel combustion, with nitrogen and sulfur oxide also released through the use of coal to produce electricity. 
 
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 Less acidic than acid rain 
 
 Acid snow is slightly less acidic than acid rain, due to the crystalline structure of ice as it falls. The pH of acid snow ranges from 4.4 to 4.6, while acid rain varies from a pH of 4.2 to 4.4. 
 
 Roughly thirty percent of land on the planet is covered by snow during the Winter, with cycles of thawing and re-freezing occurring throughout the Winter months as temperatures rise and fall. 
 
 These freeze-thaw cycles give an opportunity for the sulfuric and nitric acid in acid snow to pool in one area, leading to a very dangerous environmental phenomenon known as the acid pulse, once Spring comes and melts the snow on the ground. 
 
 The Acid Pulse 
 
 As longstanding snow starts to melt, the pH of the initial stream of melt-water is often between 3.4 and 3.6, with this rush of water into the soil and nearby lakes and streams called an acid pulse. This jolt of acid damages soil and bodies of water during the early Spring, a critical growth time for plants and wildlife. The acid pulse decreases the pH of surrounding streams and small lakes by as much as one pH unit. A single pH unit change may not sound substantial, but pH is measured on a logarithmic scale, so a one unit decrease is a ten-fold increase in acid content. 
 
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 The acidic runoff is of particular danger to eggs in the soil and water; eggs preparing to hatch with the change of seasons. The pulse only lasts for a few days before the majority of the acid content is exhausted and the pH returns to a normal level. 
 
 Salamander populations observed in Colorado experienced a 70% decline in viability due to damage to the eggs from an acid pulse. Monitoring of acid snow in New York State showed that an acid pulse killed over fifty-thousand recently hatched trout in a single lake. 
 
 Not new, but needs to be monitored 
 
 Acidic snow is not a new phenomenon, but it is one with a hidden backlash when Spring comes. This backlash calls for increased monitoring of the effect of acid snow on wildlife as it falls, along with the sudden change in water and soil pH that comes along with release of its acid pulse in the Spring. 
 
 Images courtesy of the Bureau of Land Management, Scott Egan and the University of Rhode Island, ||||| (CNN) A massive "bombogenesis" -- an area of rapidly declining low pressure -- will wreak havoc on the Northeast this week, threatening hurricane-force winter wind gusts and blinding snow. 
 
 The bombogenesis will result in what's known as a "bomb cyclone." And the bomb cyclone, expected to strike Thursday, will likely dump 6 to 12 inches of snow in New England and hurl 40- to 60-mph gusts. 
 
 People try to keep warm in New York's Times Square on December 27. 
 
 People try to keep warm in New York's Times Square on December 27. 
 
 Two women take a selfie in front of a partially frozen fountain in New York City on Wednesday, December 27. 
 
 Two women take a selfie in front of a partially frozen fountain in New York City on Wednesday, December 27. 
 
 Karlee Winter and her brother Samuel Espinoza shovel snow from their neighbor's sidewalk in Dubuque, Iowa, on December 28. 
 
 Karlee Winter and her brother Samuel Espinoza shovel snow from their neighbor's sidewalk in Dubuque, Iowa, on December 28. 
 
 A man digs his car out in his driveway in Erie, Pennsylvania, on December 29. 
 
 A man digs his car out in his driveway in Erie, Pennsylvania, on December 29. 
 
 Jose Nieto uses a leaf blower to clear snow from the steps of a sick neighbor's house in Bloomington, Illinois, on December 29. 
 
 Jose Nieto uses a leaf blower to clear snow from the steps of a sick neighbor's house in Bloomington, Illinois, on December 29. 
 
 A man in Erie, Pennsylvania, walks with his groceries in a cart on December 29. 
 
 A man in Erie, Pennsylvania, walks with his groceries in a cart on December 29. 
 
 The Cloud Gate sculpture is blanketed with snow in Chicago's Millennium Park on December 31. 
 
 The Cloud Gate sculpture is blanketed with snow in Chicago's Millennium Park on December 31. 
 
 Two photographers are silhouetted against the frozen surface of the Reflecting Pool in Washington as they capture the first sunrise of the new year. 
 
 Two photographers are silhouetted against the frozen surface of the Reflecting Pool in Washington as they capture the first sunrise of the new year. 
 
 A barge cuts through ice on the Ohio River as it passes under the West End Bridge, along the North Shore district in Pittsburgh on January 1. 
 
 A barge cuts through ice on the Ohio River as it passes under the West End Bridge, along the North Shore district in Pittsburgh on January 1. 
 
 Firefighter Bobby Lehman, with his helmet and gear caked in ice, tries to thaw out after battling a fire in Nahant, Masschusetts, on Monday, January 1. 
 
 Firefighter Bobby Lehman, with his helmet and gear caked in ice, tries to thaw out after battling a fire in Nahant, Masschusetts, on Monday, January 1. 
 
 Icicles form on a outdoor string of lights in Houston on January 2. 
 
 Icicles form on a outdoor string of lights in Houston on January 2. 
 
 A woman in Chicago walks to work in sub-zero temperatures on Tuesday, January 2. 
 
 A woman in Chicago walks to work in sub-zero temperatures on Tuesday, January 2. 
 
 A light layer of snow dusts oak trees and Spanish moss in Savannah, Georgia, on January 3. 
 
 A light layer of snow dusts oak trees and Spanish moss in Savannah, Georgia, on January 3. 
 
 A check-in area stands empty at Boston's Logan International Airport on January 3. Thousands of flights have been canceled across the country. 
 
 A check-in area stands empty at Boston's Logan International Airport on January 3. Thousands of flights have been canceled across the country. 
 
 A New Jersey State Police boat maneuvers through ice on the Delaware River on January 3. 
 
 A New Jersey State Police boat maneuvers through ice on the Delaware River on January 3. 
 
 A tree and rowhouse are partially covered by ice after a water main break in Catonsville, Maryland, on January 3. 
 
 A tree and rowhouse are partially covered by ice after a water main break in Catonsville, Maryland, on January 3. 
 
 Omar Elkhalidi scrapes ice off his windshield in Savannah, Georgia, on January 3. Few motorists ventured out in freezing rain that coated bridges and ramps with ice, forcing police to close roads and highways. 
 
 Omar Elkhalidi scrapes ice off his windshield in Savannah, Georgia, on January 3. Few motorists ventured out in freezing rain that coated bridges and ramps with ice, forcing police to close roads and highways. 
 
 A man walks through the streets of Boston as snow begins on January 4. The brutal cold comes after a "bomb cyclone" dumped more than a foot of snow across eight states. 
 
 A man walks through the streets of Boston as snow begins on January 4. The brutal cold comes after a "bomb cyclone" dumped more than a foot of snow across eight states. 
 
 Rebecca Hollis drags her suitcases through New York's Times Square on January 4. 
 
 Rebecca Hollis drags her suitcases through New York's Times Square on January 4. 
 
 A thin layer of ice covers ornamental plants on January 4 in Plant City, Florida. Temperatures in central Florida dipped to below freezing. Growers spray water on the plants to help protect them from extreme cold. 
 
 A thin layer of ice covers ornamental plants on January 4 in Plant City, Florida. Temperatures in central Florida dipped to below freezing. Growers spray water on the plants to help protect them from extreme cold. 
 
 Workers on January 4 place sandbags in front of the Aquarium subway station to protect against flooding from Boston Harbor in Boston. 
 
 Workers on January 4 place sandbags in front of the Aquarium subway station to protect against flooding from Boston Harbor in Boston. 
 
 A jogger is bundled up against the cold near the Chicago River on Thursday, January 4, in Chicago. 
 
 A jogger is bundled up against the cold near the Chicago River on Thursday, January 4, in Chicago. 
 
 Mollie Lane carries a shovelful of snow down a street while digging her car out in Boston on January 5. 
 
 Mollie Lane carries a shovelful of snow down a street while digging her car out in Boston on January 5. 
 
 Apartment buildings in New York City poke out from the snow on January 5. 
 
 Apartment buildings in New York City poke out from the snow on January 5. 
 
 A pedestrian walks by a statue of George Washington in Boston's Public Garden on Friday, January 5, the morning after a massive storm. Blasts of arctic air have brought weather-related deaths, record low temperatures and historic amounts of snowfall to parts of the United States. 
 
 A pedestrian walks by a statue of George Washington in Boston's Public Garden on Friday, January 5, the morning after a massive storm. Blasts of arctic air have brought weather-related deaths, record low temperatures and historic amounts of snowfall to parts of the United States. 
 
 By the end of this week, parts of the Northeast will be colder than Mars. 
 
 The impending storm led to more than 2,700 preemptive US flight cancellations for Thursday, according to Flightaware.com. 
 
 At Mount Washington Observatory in New Hampshire, the temperature will plunge to minus 35 degrees Friday night into Saturday, weather observer Taylor Regan said. At last check several days ago, the high temperature on Mars was minus 2 degrees Fahrenheit. 
 
 But it's not just New England suffering winter's wrath. Freezing rain, sleet and snow are smothering parts of the Southeast on Wednesday. For some in the South, the sight of snow was a first 
 
 Deep freeze across South Carolina 
 
 Record snowfall left the Palmetto State's signature palm plants covered in white stuff. By Wednesday afternoon, some areas had seen five to six inches of snow. 
 
 A picturesque scene Wednesday in Charleston, South Carolina. 
 
 More than 13,000 tons of salt have been scattered across the state, Gov. Henry McMaster said. 
 
 Steady snowfall blanketed Charleston in snow and ice, transforming a city that rarely sees snow into a winter wonderland. If Charleston gets four inches of snow on Wednesday as predicted, it would be the most in one day since 1989, CNN meteorologist Brandon Miller said. 
 
 The Quadriga sculpture at Belmond Charleston Place gets a makeover. 
 
 Amid the Instagram-worthy scenes, McMaster warned of dangerous conditions as evening temperatures were expected to remain below freezing through Monday. Runways at Charleston International Airport closed and the South Carolina Highway Patrol reported dozens of accidents as snow and sleet fell. 
 
 McMaster urged people to stay indoors as much as possible to minimize risk of injury. 
 
 A metal pineapple tops a fountain in Charleston. 
 
 State of emergency in Georgia 
 
 In Georgia, Gov. Nathan Deal issued a state of emergency for 28 coastal counties ahead of Wednesday's storm. 
 
 Forsyth Park in Savannah, Georgia. 
 
 Savannah/Hilton Head International Airport -- typically booming with tourists this time of year -- closed " due to severe winter weather conditions ," the airport said. 
 
 In Savannah, layers of snow covered live oak trees and Spanish moss. 
 
 The bitter conditions extended through the state. In the south-central city of Tifton, Matthew Stuart Reid shot drone footage of the snowfall, set to the music of "Winter Wonderland." 
 
 Florida gets walloped with snow 
 
 From Maine to Florida, every East Coast state has at least one weather advisory, winter storm watch, winter storm warning or blizzard warning. That's 1,500 miles of severe weather alerts. 
 
 In Tallahassee, Florida, Ernst Beliard said he's never seen snow in his 21 years there. Indeed, Tallahassee had not seen measurable snowfall since 1989, CNN meteorologist Michael Guy said. 
 
 YO ITS ACTUALLY SNOWING IN TALLAHASSEE pic.twitter.com/Ydh9pc4QPG — Big Ern (@ernstnation) January 3, 2018 
 
 Deadly freeze 
 
 At least 12 people in the US have died this week in cold-related deaths, officials said. 
 
 Six deaths were reported in Wisconsin, four in Texas, one in North Dakota and one in Missouri. 
 
 The Texas deaths included two homeless people in Houston who were exposed to freezing conditions, Houston Police Chief Art Acevedo tweeted 
 
 Bone-chilling cold, intense snow in Northeast 
 
 The bombogenesis will usher in another round of single-digit or sub-zero temperatures to the Northeast. New York City hasn't warmed up above freezing since Christmas -- and the deep freeze will just get worse as snow approaches. 
 
 New York City and Philadelphia will dip to 3 degrees this weekend, Miller said. Boston will plunge to minus 7. 
 
 With 4-6 inches of snowfall expected in New York, sanitation workers are getting ready to deploy 2,200 plows to help clear the streets. That snow, combined with "exceptionally strong winds," means crews will be working in near-whiteout conditions, New York City Sanitation Commissioner Kathryn Garcia said. 
 
 New York City schools will be closed Thursday due to the impending snowstorm, Mayor Bill de Blasio said. In Connecticut, where the storm is expected to hit after midnight, Gov. Dan Malloy urged motorists to stay off the roads if possible. 
 
 In Massachusetts, snow is expected to fall at a rate of 1-2 inches per hour starting early Thursday, Gov. Charlie Baker said. About 12 inches of snow are expected in Boston, as well as the eastern and central parts of the state. The greatest concern is along the Plymouth County coast and the area from Sandwich to Dennis on Cape Cod. 
 
 In southeast Massachusetts, the day may start with freezing rain on the Cape and the islands, Baker said. By midday, a dip in temperatures may bring snow, high winds and possible flooding from "astronomically high tide," Baker said. 
 
 Some of the cities breaking record-high temps include Los Angeles (85 degrees last Friday) and Fort Collins, Colorado (68 degrees last Friday).
– The "bombogenesis" storm now slamming the East Coast is nasty stuff, but at least forecasters aren't throwing around the phrase "acid snow." Quartz did a double-take upon hearing this weather report from Arirang News for Seoul, South Korea: "Please be sure to have an umbrella with you, as the snow that's falling in the central regions right now is acid snow, which is a mixture of snow and yellow dust." As this older story from i09 explains, "acid snow" is indeed real. And while it's less acidic than its "acid rain" counterpart, it can have a real effect on water and soil pH come springtime—a phenomenon known as "acid pulse."