Europes Little Ice Age coincided with low solar activity.
Pieter Brueghels painting The Census at Bethlehem.
A solar slump may have chilled the Northern Hemisphere.
The flickering sun may cause rapid climate change, according to a new comparison of climate records. A 200-year cold snap 10, 300 years ago seems to have coincided with a passing slump in the sun’s activity1.
Svante Bjorck of Lund University in Sweden and colleagues looked at sediments in Lake Starvatn on the Faroe Islands and in the Norwegian Sea, the width of growth rings in ancient German pine trees, and ancient ice drilled from deep within the Greenland ice sheet.
Bjorck and colleagues propose that a weakening of solar activity may have caused this mini chill. It coincided, they find, with a large increase in the amount of beryllium-10 trapped in Greenland ice - evidence of a solar flicker.
This radioactive form of beryllium is produced when cosmic rays from space collide with nitrogen and oxygen atoms in the atmosphere. The magnetic field around the Earth protects the planet from cosmic rays. This field is stronger when the sun is more active - emitting more ultraviolet radiation and displaying more sunspots - so fewer cosmic rays can penetrate.
The proposed relationship between solar activity and climate change is controversial, partly because some have tried to pin modern-day global warming on it rather than on a human-induced greenhouse effect.
There is evidence, however, linking changes in solar activity to climate fluctuations in the more recent past. Abnormally high activity around AD 1100-1250, for example, has been mooted as the cause of a period of warming in medieval Europe. And the ’Little Ice Age’ between the sixteenth and eighteenth centuries coincided with a period of low solar activity.
The most pronounced climate swings, such as ice ages, happen slowly and last a long time - 100,000 years or so. Gradual, periodic changes in the shape of the Earth’s orbit around the sun are thought to trigger these larger-scale changes.
Evidence of shorter-term climate change has been observed before in ice-core records from Greenland and Antarctica. Apparently the global average temperature can switch between today’s mild climate and ice-age frigidity in just a few decades.
Sudden shifts are thought to be mostly due to ocean circulation. When ice sheets melt at the end of an ice age, the oceans get an injection of fresh water. By making seawater less salty and therefore less dense, this can suppress the conveyor-belt circulation that normally carries warm water from the tropics to the poles. Deprived of this source of heat, the high latitudes grow cold.
PHILIP BALL | © Nature News Service
Geophysicists and atmospheric scientists partner to track typhoons' seismic footprints
16.02.2018 | Princeton University
NASA finds strongest storms in weakening Tropical Cyclone Sanba
15.02.2018 | NASA/Goddard Space Flight Center
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy