Amazon rainforest recovering from its second 100-year drought in 5 years

By: Dr. Jeff Masters , 2:32 PM GMT on December 03, 2010

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Life-giving rains have returned over the past two months to Earth's greatest rainforest--the mighty Amazon--after it experienced its second 100-year drought in five years this year. The record drought began in April, during the usual start to the region's dry season, when rainfall less than 75% of average fell over much of the southern Amazon (Figure 2.) The drought continued through September, and by October, when the rainy season finally arrived, the largest northern tributary of the Amazon River--the Rio Negro--had dropped to thirteen feet (four meters) below its usual dry season level. This was its lowest level since record keeping began in 1902. The low water mark is all the more remarkable since the Rio Negro caused devastating flooding in 2009, when it hit an all-time record high, 53 ft (16 m) higher than the 2010 record low. The 2010 drought is similar in intensity and scope to the region's previous 100-year drought, which hit the Amazon in 2005, according to Brazil's National Institute of Space Research. Severe fires burned throughout the Amazon in both 2005 and 2010, leading to declarations of states of emergencies.


Figure 1. Hundreds of fires (red squares) generate thick smoke over a 1000 mile-wide region of the southern Amazon rain forest in this image taken by NASA's Aqua satellite on August 16, 2010. The Bolivian government declared a state of emergency in mid-August due to the out-of-control fires burning over much of the country. Image credit: NASA.

Causes of the great 2010 Amazon drought
During the 20th Century, drought was a frequent visitor to the Amazon, with significant droughts occurring an average of once every twelve years. These droughts typically occurred during El Niño years, when the unusually warm waters present along the Pacific coast of South America altered rainfall patterns. But 2010 was a La Niña year. The 100-year drought of 2005 occurred in an El Niño-neutral year. Subsequent analysis of the 2005 drought revealed that it was unlike previous El Niño-driven droughts, and instead was caused by record warm sea surface temperatures in the Atlantic (Phillips et al., 2009.) These warm ocean waters affected the southern 2/3 of the Amazon though reduced precipitation and higher than average temperatures. Very similar record Atlantic sea surface temperatures were observed in 2010, and likely were the dominant cause for the 2010 drought.


Figure 2. The great Amazon drought of 2010 began in April, when portions of the southern Amazon recorded precipitation amounts less than 75% of normal (brown colors). The drought spread northward and peaked during July and August, but drew to a close by November when the rainy season began. Image credit: NOAA Climate Prediction Center.

The importance of the Amazon to Earth's climate
We often hear about how important Arctic sea ice is for keeping Earth's climate cool, but the Amazon may be even more important. Photosynthesis in the world's largest rainforest takes about 2 billion tons of carbon dioxide out of the air each year. However, in 2005, the drought reversed this process. The Amazon emitted 3 billion tons of CO2 to the atmosphere, causing a net 5 billion ton increase in CO2 to the atmosphere--roughly equivalent to 16 - 22% of the total CO2 emissions to the atmosphere from burning fossil fuels that year. According to Phillips et al., 2009, "The exceptional growth in atmospheric CO2 concentrations in 2005, the third greatest in the global record, may have been partially caused by the Amazon drought effects documented here." The Amazon stores CO2 in its soils and biomass equivalent to about fifteen years of human-caused emissions, so a massive die-back of the forest could greatly accelerate global warming. In late 2009, before the 2010 drought, the World Wildlife Federation released a report, Major Tipping Points in the Earth's Climate System and Consequences for the Insurance Sector, which suggested that odds of extreme 2005-like droughts in the Amazon had increased from once every 40 - 100 years, to once every 20 years. The study projected that the extreme droughts would occur once every two years by 2025 - 2050. This year's drought gives me concern that this prediction may be correct. The occurrence of two extreme droughts in the past five years, when no El Niño conditions were present and record warm Atlantic sea surface temperatures occurred, are suggestive of a link between global warming and extreme Amazon drought. If the climate continues to warm as expected, the future health of Earth's greatest rainforest may be greatly threatened, and the Amazon may begin acting to increase the rate of global warming. According to Rosie Fisher, a scientist at the National Center for Atmospheric Research in Boulder, Colorado who specializes in interactions between climate and forests, "I'm genuinely quite alarmed by this. In some ways it kind of reminds me of when they figured out than the Greenland ice sheet was melting much faster than the climate models predicted it would."

Deforestation in Brazilian Amazon falls to lowest rate on record
There is some good news from the Amazon--deforestation rates in the Brazilian Amazon have fallen 14% in the past year, and are at their lowest rate on record, according to mongabay.com, an environmental science and conservation news site that focuses on tropical forests. In 2009, Brazil passed a law committing to a 36 - 39% reduction in emissions of greenhouse gases. Reducing deforestation by 80% by 2020 was the primary method envisioned to achieve the reduction. Brazil is now four years ahead of that schedule, and no longer is the world's biggest deforester--Indonesia now cuts down more acreage of forest each year than Brazil does.

For more information
Nick Sundt at the WWF Climate Blog has a remarkably detailed post on this year's Amazon drought, and Dr. Joe Romm at climateprogress.org has another excellent post.

Phillips, et al., 2009, Drought Sensitivity of the Amazon Rainforest, Science 6 March 2009: Vol. 323 no. 5919 pp. 1344-1347 DOI: 10.1126/science.1164033.

I'll have new post Monday or Tuesday.

Jeff Masters

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It's even considered cold here, where 1/2 the country is technically sub-tropical.... I think I'll run out at about 3 a.m. with my thermometer to see how cold it gets tonight... lol

Anyway, I'm out for a while... gone to take a nap.

Later!
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344. beell
There you go, DAM. Would only add that as the ice crystals melt from falling throught the warm layer and into the shallow sub-freezing layer the rain drops become super-cooled.

Rain drops that are actually at or below 0°C. They don't freeze because of an absence of ice nuclei-tiny microscopic particles of dust, salt, etc that the ice can "grow" on. Except when they strike objects on the ground. Like flagpoles and roads and weather bloggers. In effect, great big ice nuclei!
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Quoting DontAnnoyMe:
Snow


Sleet


Freezing Rain

Nice!
Member Since: October 24, 2005 Posts: 0 Comments: 23107
Quoting KoritheMan:


64F. I suppose that's considered cold considering you're in the tropics.

"Considered cold??"
You betcha!
People dress like Eskimo's when it gets down to the mid 60's here LOL
Member Since: October 24, 2005 Posts: 0 Comments: 23107
Snow


Sleet


Freezing Rain
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Quoting DontAnnoyMe:


Hi Pot,

NWS definition of Freezing Rain:
Rain that falls as a liquid but freezes into glaze upon contact with the ground.

It has to be freezing at ground level. Hail and sleet is formed in the upper levels and it doesn't have to be freezing on the ground for them to land as such.

Oh, OK! Thanks.
Got my wires crossed on that one...
Member Since: October 24, 2005 Posts: 0 Comments: 23107
Quoting pottery:

Not nessesarily...
We have had the occasional hail-showers here.
And it can never get to 32F here.
More likely, strong updrafts cause frozen rain which are able to get to ground level before melting, on particularly cool nights.
I have witnessed hail once here, but the hail was probably 1/8" and melted as soon as it hit ground.
But it was bouncing off my car roof and windshield...


Hi Pot,

NWS definition of Freezing Rain:
Rain that falls as a liquid but freezes into glaze upon contact with the ground.

It has to be freezing at ground level. Hail and sleet is formed in the upper levels and it doesn't have to be freezing on the ground for them to land as such.
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Quoting pottery:

Not offhand...
but I know we have been at 18c. What is that in F? I cannot find my converter thingy..


64F. I suppose that's considered cold considering you're in the tropics.
Member Since: March 7, 2007 Posts: 521 Comments: 19144
Quoting KoritheMan:


Do you know Trinidad's all time record low, perchance?

Not offhand...
but I know we have been at 18c. What is that in F? I cannot find my converter thingy..
Member Since: October 24, 2005 Posts: 0 Comments: 23107
Quoting pottery:

Not nessesarily...
We have had the occasional hail-showers here.
And it can never get to 32F here.
More likely, strong updrafts cause frozen rain which are able to get to ground level before melting, on particularly cool nights.
I have witnessed hail once here, but the hail was probably 1/8" and melted as soon as it hit ground.
But it was bouncing off my car roof and windshield...


Do you know Trinidad's all time record low, perchance?
Member Since: March 7, 2007 Posts: 521 Comments: 19144
KOTG, I don't want to imagine being that cold, that long, again. A few days is one thing....
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Quoting DontAnnoyMe:


Freezing rain would imply 32F or lower at the surface though.

Not nessesarily...
We have had the occasional hail-showers here.
And it can never get to 32F here.
More likely, strong updrafts cause frozen rain which are able to get to ground level before melting, on particularly cool nights.
I have witnessed hail once here, but the hail was probably 1/8" and melted as soon as it hit ground.
But it was bouncing off my car roof and windshield...
Member Since: October 24, 2005 Posts: 0 Comments: 23107
Quoting JRRP:

jajajajajajajja
its only 4 months
Member Since: July 15, 2006 Posts: 165 Comments: 52384
Well, I found this online:

On Wednesday, January 19 at 6:10 AM, West Palm Beach reported snow falling for the first time on record. An hour later, the Miami area weather forecast was amended to include the likelihood of snow mixed with rain. This was the first forecast for snow ever issued for the city.

For most of Greater Miami, the forecast was on the mark. From 8:30 to 9:00 AM, snow reports emanated from the Fort Lauderdale/Hollywood International Airport in Broward County. Homestead, 23 miles (37 km) southwest of Miami in southern Dade County (latitude 25 deg, 30 minutes), reported snow falling. While observers at Miami International Airport never officially reported snow, radar picked up echos of snow falling around the city, and there were numerous public sightings of the unusual precipitation, including some from Miami Beach.

The fine granular snow crystals dusted the palms and baptised the ground with white water, but they soon melted. Most children, and many adults, had never seen snow before -- at least not live and in concert. "They were ecstatic, running around with their tongues out, trying to catch the snow in their mouths," commented Wilton Manors Elementary School principal, Mary Crum.

The snow and cold continued to move southeastward, bringing snow mixed with cold rain to Freeport in the Bahamas. Within a couple of days, weather conditions returned to near normal in south Florida.

Considering that Grand Bahama is near 30 N, I suppose it's possible. And it seems that contrary to my earlier comment, the Met Office does admit that it happened:

http://www.bahamasweather.org.bs/index.php?page=climate
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331. JRRP
Quoting KEEPEROFTHEGATE:

jajajajajajajja
Member Since: August 16, 2007 Posts: 0 Comments: 5085
Quoting BahaHurican:
Some residents of Freeport, Grand Bahama swear it did during the cold snap of 1977, but the Met office hasn't substantiated their claims... they say it never got cold enough for more than some hail / freezing rain at best....


Freezing rain would imply 32F or lower at the surface though.
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Quoting KEEPEROFTHEGATE:
has it ever snowed in bahamas
Some residents of Freeport, Grand Bahama swear it did during the cold snap of 1977, but the Met office hasn't substantiated their claims... they say it never got cold enough for more than some hail / freezing rain at best....
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Quoting pottery:

It has been getting down to 73 here as well the last couple of days.
Coldest months are generally Jan and Feb when it can get to a beastly 65! LOL! (usually around 3:00 am, but still!!!)
65 i won't see 65 till april
Member Since: July 15, 2006 Posts: 165 Comments: 52384
Quoting GeoffreyWPB:


At least he’s wearing sensible shoes.

LOL
Member Since: October 24, 2005 Posts: 0 Comments: 23107
Quoting BahaHurican:
It's really cooling off here now. Not even 9 p.m. yet, and already at 72 degrees. Last week we weren't hitting 72 until after midnight.

Should be interesting to see how close to 60 we get tonight. Below 60 is space heater weather in the Bahamas.... lol...

And lest u call us wimpy, recall that there is NO insulation of homes, no indoor heating in our fair land... and generally no indoor fireplaces either.... so if the temp gets to 45 degrees here, it's almost 45 degrees inside as well as outside.... meanwhile in Destin and Sarasota pple have their heat set to a toasty 72, and the insulation is fighting off the cooler temps....

Just sayin'....

It has been getting down to 73 here as well the last couple of days.
Coldest months are generally Jan and Feb when it can get to a beastly 65! LOL! (usually around 3:00 am, but still!!!)
Member Since: October 24, 2005 Posts: 0 Comments: 23107
Quoting CybrTeddy:


Looks like he caught a 'cold' as well.
well it is cold out right now its 23.9f with a windchill of 7.9f outside
Member Since: July 15, 2006 Posts: 165 Comments: 52384
Quoting CybrTeddy:


Looks like he caught a 'cold' as well.


At least he’s wearing sensible shoes.
Member Since: Posts: Comments:
Quoting BahaHurican:
It's really cooling off here now. Not even 9 p.m. yet, and already at 72 degrees. Last week we weren't hitting 72 until after midnight.

Should be interesting to see how close to 60 we get tonight. Below 60 is space heater weather in the Bahamas.... lol...

And lest u call us wimpy, recall that there is NO insulation of homes, no indoor heating in our fair land... and generally no indoor fireplaces either.... so if the temp gets to 45 degrees here, it's almost 45 degrees inside as well as outside.... meanwhile in Destin and Sarasota pple have their heat set to a toasty 72, and the insulation is fighting off the cooler temps....

Just sayin'....
has it ever snowed in bahamas
Member Since: July 15, 2006 Posts: 165 Comments: 52384
Quoting pottery:

I dont know. He looks pretty "cool" to me.............


Looks like he caught a 'cold' as well.
Member Since: Posts: Comments:
It's really cooling off here now. Not even 9 p.m. yet, and already at 72 degrees. Last week we weren't hitting 72 until after midnight.

Should be interesting to see how close to 60 we get tonight. Below 60 is space heater weather in the Bahamas.... lol...

And lest u call us wimpy, recall that there is NO insulation of homes, no indoor heating in our fair land... and generally no indoor fireplaces either.... so if the temp gets to 45 degrees here, it's almost 45 degrees inside as well as outside.... meanwhile in Destin and Sarasota pple have their heat set to a toasty 72, and the insulation is fighting off the cooler temps....

Just sayin'....
Member Since: Posts: Comments:
Member Since: July 15, 2006 Posts: 165 Comments: 52384
49 JF your having a heat wave
Member Since: July 15, 2006 Posts: 165 Comments: 52384
Quoting Dakster:
KOTG - You don't look so good in the that photo...

I dont know. He looks pretty "cool" to me.............
Member Since: October 24, 2005 Posts: 0 Comments: 23107
KOTG - You don't look so good in the that photo...
Member Since: March 10, 2006 Posts: 0 Comments: 9765
Member Since: July 15, 2006 Posts: 165 Comments: 52384
Freeze Watch
URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
755 PM EST SUN DEC 5 2010

...FREEZE WARNING TONIGHT FOR LEVY COUNTY...

...FREEZE WATCH IN EFFECT FROM LATE TONIGHT THROUGH MONDAY
MORNING FOR MUCH OF WEST CENTRAL FLORIDA...

.STRONG CANADIAN HIGH PRESSURE DROPPING INTO THE WESTERN GULF
TONIGHT WILL BRING CLEAR SKIES AND COLD TEMPERATURES.

FLZ042-043-048-049-051-052-055>057-061-061300-
/O.NEW.KTBW.FZ.A.0022.101207T0600Z-101207T1400Z/
CITRUS-SUMTER-HERNANDO-PASCO-HILLSBOROUGH-POLK-MANATEE-HARDEE-
HIGHLANDS-DE SOTO-
INCLUDING THE CITIES OF...CRYSTAL RIVER...INVERNESS...BUSHNELL...
THE VILLAGES...BROOKSVILLE...SPRING HILL...NEW PORT RICHEY...
ZEPHYRHILLS...BRANDON...TAMPA...LAKELAND...WINTER HAVEN...
BRADENTON...WAUCHULA...SEBRING...AVON PARK...ARCADIA
755 PM EST SUN DEC 5 2010

...FREEZE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING...

THE NATIONAL WEATHER SERVICE IN TAMPA BAY AREA - RUSKIN FL HAS
ISSUED A FREEZE WATCH...WHICH IS IN EFFECT FROM LATE MONDAY NIGHT
THROUGH TUESDAY MORNING.

HIGH PRESSURE WILL BUILD OVER THE REGION WITH STRONG RADIATIONAL
COOLING ACROSS WEST CENTRAL FLORIDA MONDAY NIGHT. THIS WILL ALLOW
TEMPERATURES TO DROP BELOW FREEZING ACROSS MUCH OF THE REGION AWAY
FROM THE IMMEDIATE COAST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WATCH IS ISSUED FOR THE POTENTIAL OF A WIDESPREAD AND
DAMAGING FREEZE WITHIN 24 TO 48 HOURS. DURING THE FREEZE
PERIOD...TEMPERATURES MAY REMAIN BELOW 32 DEGREES FOR MORE THAN
8 HOURS IN COLDER INLAND AREAS MAINLY NORTH OF TAMPA.

&&

$$






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haha.. i guess i will try back later. darn
Member Since: August 15, 2008 Posts: 0 Comments: 2133
please try again later
Member Since: July 15, 2006 Posts: 165 Comments: 52384
Quoting FLPandhandleJG:
anybody alive??


Apparently not.

This is an automated message. Please do not reply.
Member Since: September 21, 2010 Posts: 1 Comments: 3690
anybody alive??
Member Since: August 15, 2008 Posts: 0 Comments: 2133
What kind of effect is deforestation having on the precipitation of the Amazon Rainforest?
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First post with the new Lappy Toppy from Toshiba,..

A colder Snappier NOLA in da Future?




Highs on Monday are again only expected to rise to the lower 50s
under sunny skies. Monday night...clear skies...near calm to light
winds...and dewpoints in the upper teens to lower 20s will combine
to provide optimal conditions for a significant period of freezing
temperatures. The main change is to extend the freeze warning to
include all the lower portions of the south central and southeast
parishes. The immediate coastal areas of these zones...from near
Dulac to Port Fourchon and Grand Isle to Venice/Boothville are not
expected to drop to freezing...however...areas just inland like
Houma to Galliano to Pointe a la Hache are likely to drop below
freezing.
Member Since: July 3, 2005 Posts: 415 Comments: 125715
Some moisture in da Atlantic babeee...
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Hawaii in da sun.
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A few blobs in the extreme Western Pacific..Still lookin Nina out yonder..
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Big wad of dry air in the pacific...
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Quoting Dakster:
I have some ideas, but since this is a family blog I'll keep them to myself...
lol
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<
Member Since: July 15, 2006 Posts: 165 Comments: 52384
< ;)
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Quoting xcool:
12zzzz CMC snow for the northshore mix on southshore new orleans


How does that translate for the Florida Panhandle and SE Alabama from Mobile to Destin? We here typically have the same weather patterns as NO.
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black oak is where you go win $ at and play all kinds of games
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Quoting hydrus:
Good afternoon Taz...How did you win $546.00 ?



at black oask
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297. xcool
12zzzz CMC snow for the northshore mix on southshore new orleans
Member Since: September 26, 2009 Posts: 2 Comments: 15603
Hi everyone! We got more rain this morning then I thought we would get. As far as Christmas of 1989 I remember that Christmas real well! ON the night of the 23rd my Dad and I went from Sarasota to Tampa, because we heard it was snowing in Tampa! We got back home and it ended up snowing more in Sarasota than in Tampa!
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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.