Navigation Links
New study finds 'nighttime heat waves' increasing in Pacific Northwest
Date:7/22/2013

CORVALLIS, Ore. A new study has found that heat waves are increasing in the western portions of the Pacific Northwest, but not the kind most people envision, with scorching hot days of temperatures reaching triple digits.

These heat waves occur at night.

Researchers documented 15 examples of "nighttime heat waves" from 1901 through 2009 and 10 of those have occurred since 1990. Five of them took place during a four-year period from 2006-09. And since the study was accepted for publication in the Journal of Applied Meteorology and Climatology, another nighttime heat wave took place at the end of this June, the authors point out.

"Most people are familiar with daytime heat waves, when the temperatures get into the 100s and stay there for a few days," said Kathie Dello, deputy director of the Oregon Climate Service at Oregon State University and a co-author on the study. "A nighttime heat wave relates to how high the minimum temperature remains overnight.

"Daytime events are usually influenced by downslope warming over the Cascade Mountains, while nighttime heat waves seem to be triggered by humidity," said Dello, who is in OSU's College of Earth, Ocean, and Atmospheric Sciences. "Elevated low-level moisture at night tends to trap the heat in."

In their study, Dello and co-authors Karin Bumbaco and Nicholas Bond from the University of Washington defined heat waves as three consecutive days of temperatures at the warmest 1 percentile over the past century. Using that standard criterion, they documented 13 examples of daytime heat waves during the time period from 1901 to 2009. Only two of those occurred in the last 20 years.

In contrast, nighttime heat waves have been clustered over the past two decades, with what appears to be accelerating frequency. A warming climate suggests the problem may worsen, studies suggest.

"If you look at nighttime temperatures in Oregon and compared them to say the Midwest, people there would laugh at the concept of a Pacific Northwest heat wave," Dello said. "However, people in the Midwest are acclimated to the heat while in the Northwest, they are not. People in other regions of the country may also be more likely to have air conditioning in their homes.

On occasion, daytime and nighttime heat waves coincide, Dello said, as happened in 2009 when temperatures in the Pacific Northwest set all-time records in Washington (including 103 degrees at SeaTac), and temperatures in Oregon surpassed 105 degrees in Portland, Eugene, Corvallis and Medford. It was the second most-intense daytime heat wave in the last century, but lasted only three days by the 1 percentile definition.

However, that same stretch of hot weather in 2009 results in a nighttime heat wave that extended eight days, by far the longest stretch since records were kept beginning in 1901.

The latest nighttime heat wave began in late June of this year, and continued into early July, Dello said.

"Like many nighttime heat waves, a large high-pressure ridge settled in over the Northwest, while at the same time, some monsoonal moisture was coming up from the Southwest," she pointed out. "The high swept around and grabbed enough moisture to elevate the humidity and trap the warm air at night."


'/>"/>

Contact: Kathie Dello
kdello@coas.oregonstate.edu
541-737-8927
Oregon State University
Source:Eurekalert

Related biology news :

1. Study finds missing piece of pediatric cancer puzzle
2. Its not just the heat -- its the ozone: Study highlights hidden dangers
3. LSUHSC researcher awarded NCI grant to study link between chronic inflammation and cancer
4. Healthrageous, United BioSource And Boehringer Ingelheim Launch SMART Digital Diabetes Study
5. Study identifies Deepwater Horizon debris as likely source of Gulf of Mexico oil sheens
6. Carnegie Mellon researchers develop artificial cells to study molecular crowding and gene expression
7. U of T-led study cracks universal RNA code, suggests a new cause for autism
8. Study finds surprising benefits about diary cow inflammation
9. Metastatic pancreatic, primary breast cancer have common growth mechanisms, study suggests
10. Journal highlights Arctic sea ice study by UM professor
11. Innovative MIT study estimates extent to which air pollution in China shortens human lives
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/7/2017)...   MedNet Solutions , an innovative SaaS-based eClinical ... research, is pleased to announce that the latest release ... flexible and award winning eClinical solution, is now available ... is a proven Software-as-a-Service (SaaS) clinical research technology platform ... also delivers an entire suite of eClinical tools to ...
(Date:2/3/2017)... ANTONIO , Feb. 3, 2017  Texas Biomedical Research ... Dr. Larry Schlesinger as the Institute,s new ... Texas Biomed effective May 31, 2017. He is currently the ... Director of the Center for Microbial Interface Biology at Ohio ... Schlesinger as the new President and CEO of Texas Biomed," ...
(Date:2/2/2017)... 2017  Central to its deep commitment to ... The Japan Prize Foundation today announced the laureates ... the envelope in their respective fields of Life ... are being recognized with the 2017 Japan Prize ... contribute to the advancement of science and technology, ...
Breaking Biology News(10 mins):
(Date:2/23/2017)... 23, 2017 ... per share data, unaudited)Three Months Ended December 31,Twelve Months ... $         ...   89026%Aldurazyme Net Product Revenue ... Net Product Revenue  756025%297303(2)%Vimizim Net ...
(Date:2/23/2017)... , Feb. 23, 2017  Seattle,s upscale Capitol Hill neighborhood, ... strange place for a head lice treatment salon to set ... a Tuscan restaurant and a French bistro on E Madison ... "We aren,t just any old lice clinic, we pride ourselves ... comfortable, and release some of the stigma associated with lice. ...
(Date:2/23/2017)... , ... February 23, 2017 , ... ... (such as insulin, cortisol, CRP, adiponectin, uric acid, and/or other biomarkers or SNPs ... Insulin Assay from Salimetrics’ SalivaLab , the relationship between insulin and other ...
(Date:2/23/2017)... UK (PRWEB) , ... February 22, 2017 , ... ... optics and photonics , have been named Fellows of the Society this year, ... technical contributions in the multidisciplinary fields of optics, photonics, and imaging as well ...
Breaking Biology Technology: