"We used to have this season from October to April where we had a chance for a storm," says Stephanie A. McAfee of the University of Arizona in Tucson, who is lead author of the new study. "Now it's from October to March."
The new study is the first to link the poleward movement of the westerly winds to the changes observed in the West's winter storm pattern. The change in the westerlies is driven by the atmospheric effects of global warming and the ozone hole combined."When you pull the storm track north, it takes the storms with it,"
"During the period it's raining less, it also tends to be warmer than it used to be," McAfee says. "We're starting to see the impacts of climate change in the late winter and early spring, particularly in the Southwest. It's a season-specific kind of drought."
Having drier, warmer conditions occur earlier in the year will affect snowpack, hydrological processes and water resources, McAfee says. In prior studies, other researchers have linked warmer, drier springs to more and larger forest fires.
"We're used to thinking about climate change as happening sometime in the future to someone else," Russell says. "But this is right here and affects us now. The future is here."
Atmospheric scientists have documented that the westerly winds, or storm track, have been shifting poleward for several decades. The southwestern U.S. has experienced less winter precipitation during the same period.
Computer models of future climate and atmospheric conditions suggest the storm track will continue to move north and that precipitation will continue to decrease in the southwestern U.S.
The timing of the change from wet, cool winter weather to the warmer dry season is important for many ecological processes in the arid Southwest. Therefore, McAfee wanted to know how the shift in the storm track affected precipitation during the transition from winter to spring.
For the period 1978 to 1998, the researchers compared the month- to-month position of the winter storm track, temperature and precipitation records from the western U.S., and pressure at different levels in the atmosphere.
The team used a statistical method called Monte Carlo simulations to test whether the coincidence of storm track and weather patterns had occurred by chance.
Russell says the results of the simulation showed, "It's very rare that you get this distribution by chance." Therefore, she says, the changes in late winter precipitation in the West from 1978 to 1998 are related to the changes in the storm track path for that same time period.
McAfee says her next step is investigating whether western vegetation has changed as the storm track has changed.
The National Oceanic and Atmospheric Administration funded this research.
Peter Weiss | AGU
A 3-D look at the 2015 El Niño
29.05.2017 | NASA/Goddard Space Flight Center
'Tiny clocks' crystallize understanding of meteorite crashes
29.05.2017 | University of Western Ontario
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Physics and Astronomy
29.05.2017 | Physics and Astronomy
29.05.2017 | Earth Sciences