<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:16px"><div class="" style=""><a href="http://www.mercurynews.com/drought/ci_27070897/california-drought-worst-1-200-years-new-study" class="" style="">http://www.mercurynews.com/drought/ci_27070897/california-drought-worst-1-200-years-new-study</a><br class="" style=""></div><div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"><div style="font-family: times new roman, new york, times, serif; font-size: 16px;" class=""><div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" class=""><div class="" style=""><div id="yiv8384612575" class="" style=""><div dir="ltr" class="" style=""><span class="" style=""><b class="" style="">By Paul Rogers</b></span><span class="" style=""><i class="" style=""> <br class="" style=""><br class=""
style="">San Jose Mercury News <a rel="nofollow" class="" ymailto="mailto:progers@mercurynews.com" target="_blank" href="mailto:progers@mercurynews.com" style="">progers@mercurynews.com</a>
</i></span><span class="" style=""> <br class="" style=""><br class="" style=""> The last three years of drought
were the most severe that California has experienced in at least 1,200
years, according to a new scientific study published Thursday.<br class="" style=""><br class="" style="">
The study provides the state with breathtaking new historical context
for its low reservoirs and sinking water tables, even as California
celebrated its first good soaking of the season.<br class="" style=""><br class="" style=""> Analyzing tree rings that date</span><span class="" style="">
back to 800 A.D. — a time when Vikings were marauding Europe and the
Chinese were inventing gunpowder — there is no threeyear period when
California’s rainfall has been as low and its temperatures as hot as
they have been from 2012 to 2014, the researchers found.<br class="" style=""><br class="" style=""> “We
were really surprised. We didn’t expect this,” said one of the study’s
authors, Daniel Griffin, an assistant professor in the University of
Minnesota’s department of geography, environment and society.</span><span class="" style=""><b class="" style=""> <br class="" style=""><br class="" style="">DROUGHTPAGE5</b></span>
<br class="" style=""><br class="" style="">
<hr class="" style=""><br class="" style=""><img src="http://eurekatimesstandard.ca.newsmemory.com/newsmemvol2/california/eurekatimesstandard/20141205/ets_sly_141205_a_001.pdf.0/img/Image_0.jpg" height="159" width="256" class="" style=""><br class="" style=""><span class="" style="">
California’s drought-ravaged reservoirs are running so low that state
water deliveries to some metropolitan areas have all but stopped, and
cutbacks are forcing growers to fallow fields.</span><span class="" style=""> <br class="" style=""></span><div id="yiv8384612575continuationAfter" class="" style=""><br class="" style=""><span class="" style="">
The report, published in the journal of the American Geophysical
Union, was written by researchers at Massachusetts’ Woods Hole
Oceanographic Institution and the University of Minnesota. </span><br class="" style=""><br class="" style=""><span class="" style="">
The scientists measured tree rings from 278 blue oaks in central and
Southern California. Tree rings show the age of trees, and their width
shows how wet each year was because trees grow more during wet years. </span><br class="" style=""><br class="" style=""><span class="" style="">
The researchers compared the information to a database of other tree
ring records from longer-living trees like giant sequoias and
bristlecone pines, dating back 1,200 years. </span><br class="" style=""><br class="" style=""><span class="" style="">
Meanwhile, the rain that California received this week provided a
promising start to a winter that water managers say needs to be
relentless and drenching to break the drought cycle. </span><br class="" style=""><br class="" style=""><span class="" style="">
“It’s a good beginning,” said Art Hinojosa, chief of hydrology at the
state Department of Water Resources. “But we need storm after storm
after storm if we have any hope of getting out of the drought this
year.” </span><br class="" style=""><br class="" style=""><span class="" style=""> By April, he said,
California needs at least eight more major storm systems like the one
this week — as well as many smaller systems — to fill its dangerously
low reservoirs and break the drought. Rain and snow this winter needs to
be at least 150 percent of average for the reservoirs to fill, Hinojosa
said. </span><br class="" style=""><br class="" style=""><span class="" style=""> This week’s storm was the
biggest to hit California in roughly two years. Many parts of the state
received between 2 and 4 inches of rain, doubling or tripling their
totals since July. </span><br class="" style=""><br class="" style=""><span class="" style=""> More important,
several of the state’s large reservoirs began to receive moderate
amounts of runoff, as the parched ground became saturated. Lake Shasta
gained about 6,000 acre-feet through midnight Wednesday, and Oroville
Reservoir in Butte County added 17,000 acre-feet. But that new water
boosted Shasta’s storage by less than 1 percent, leaving it at only 23
percent full. It added 3 percent at Oroville, which is now 26 percent
full, the lowest level in its history for this time of year. </span><br class="" style=""><br class="" style=""><span class="" style="">
The Sierra snowpack told a similar story. A week ago, it was at 24
percent of the average for this time of year. Thursday, after a week of
snow, it was at 39 percent — still far below normal. </span><br class="" style=""><br class="" style=""><span class="" style=""> But more rain and snow is on the way. </span><br class="" style=""><br class="" style=""><span class="" style="">
The Weather Service issued a report late Thursday saying that
because of storms brewing as far away as Hawaii, projections out to Dec.
18 show that “wetter than normal conditions are favored.” </span><br class="" style=""><br class="" style=""><span class="" style="">
Experts emphasize that a three-year drought cannot be erased in a few
days. Not only are reservoirs low, but there are huge “rainfall
deficits” built up from the past three years. </span><br class="" style=""><br class="" style=""><span class="" style="">
Overall, 94 percent of California remains in “severe drought,”
according to Thursday’s edition of the Federal Drought Monitor, a weekly
report from the U.S. Department of Agriculture and other agencies. </span><br class="" style=""><br class="" style=""><span class="" style="">
It was the tree-ring study showing California suffering its worst
drought in 1,200 years, however, that received the most attention
Thursday. </span><br class="" style=""><br class="" style=""><span class="" style=""> The researchers took core
samples, which don’t harm the living trees, of oaks as old as 500 years
and oak logs dating back more than 700 years, the University of
Minnesota’s Griffin said. And they sanded down the wood with extremely
finegrain sandpaper, magnifying the rings 40 times under a microscope
and measuring them to within one one-thousandth of a millimeter. </span><br class="" style=""><br class="" style=""><span class="" style="">
They then compared the findings to the North American Drought Atlas, a
detailed collection of other tree-ring data that goes back 1,200 years
and includes measurements from ancient trees such as giant sequoias
and bristlecone pines. The atlas calculates temperature and rainfall for
those years by comparing the tree rings with tree rings from the past
100 years, when modern records were kept. Although there are 37 times
over the past 1,200 years when there were three-year dry periods in
California, no period had as little rainfall and as hot of temperatures
as 2012-14, the scientists concluded. </span><br class="" style=""><br class="" style=""><span class="" style="">
With climate change already warming the earth, the last three years
in California could become a more recurring event, they said. </span><br class="" style=""><br class="" style=""><span class="" style=""> “This kind of drought is what we expect to see more of in the future,” said Griffin. “Maybe the future is now.” <span style="font-style:italic;" class="">Mercury News staff writer David E. Early contributed to this report.</span> </span></div></div></div><br class="" style=""><br class="" style=""></div> </div> </div> </div> </div></body></html>