World’s largest lakes reveal climate change trends

Science Daily  January 21, 2021 Researchers at Michigan Technological University studied the five Laurentian Great Lakes bordering the U.S. and Canada; the three African Great Lakes, Tanganyika, Victoria, and Malawi; Lake Baikal in Russia; and Great Bear and Great Slave lakes in Canada. These 11 lakes hold more than 50% of the surface freshwater that millions of people and countless other creatures rely on. The rate of carbon fixation, that is the rate at which the algae photosynthesize, indicates change in the whole lake and that has ramifications all the way up the food chain, from the zooplankton to the […]

Parts of The Amazon Rainforest Are Heading For Collapse by 2064, New Report Shows

Science Alert  January 1, 2021 Researchers at the University of Florida reviewed recent research on the Amazon rainforest to reach a grim conclusion. Lengthening dry seasons will soon no longer allow the rainforest canopies the five years they need in between dry seasons to recover from fires, allowing flammable grasses and shrubs to take over. Southern Amazonia can expect to reach a tipping point sometime before 2064 at the current rate of dry season lengthening. Like dominos, models predict once 30-50 percent deforestation is reached in the south, this will decrease the amount of rain by up to 40 percent […]

Change in global precipitation patterns as a result of climate change

Science Daily  December 17, 2020 An international team of researchers (Germany, Ireland, Brazil, Mexico) demonstrated that regional hydroclimates controlled by the Northern Hemisphere mid-latitude storm tracks and the African and South American Monsoons changed synchronously during the last 10,000 years. They argue that these regional hydroclimate variations are connected and reflect the adjustment of the atmospheric poleward energy transport to the evolving differential heating of the Northern and Southern Hemispheres. These results indicate that changes in latitudinal insolation gradients and associated variations in latitudinal temperature gradients exert important control on atmospheric circulation and regional hydroclimates. Since the current episode of […]

The natural ‘Himalayan aerosol factory’ can affect climate

Science Daily  December 7, 2020 Pre-industrial aerosol concentration and composition particles formed directly in the atmosphere from gaseous precursors, constitutes a large uncertainty in the anthropogenic radiative forcing. From their observations taken at the remote Nepal Climate Observatory Pyramid station at 5,079 m above sea level an international team of researchers (Finland, Italy, Switzerland, France, Estonia, USA – industry) shows that up-valley winds funnel gaseous aerosol precursors to higher altitudes. During this transport, these are oxidized into compounds of very low volatility, which rapidly form many aerosol particles. These are transported into the free troposphere, suggesting that the whole Himalayan region […]

Once in a lifetime floods to become regular occurrences by end of century

Science Daily  December 2, 2020 Based on the anticipated greenhouse gas concentration by the end of the 21st century a team of researchers in the US (Stevens Institute of Technology, Princeton University) conducted high resolution simulations for different scenarios to find the probability of different flood levels being reached, assuming emissions remain at a high level. They studied how sea level rise and hurricane climatology change would impact the area in the future due to storm surge and wave hazards. They found that the historical 100-year flood level would become a nine-year flood level by mid-century (2030-2050) and a one-year […]

Scientists Detect ‘Superbolts’ 1,000 Times Brighter Than Typical Lightning Strikes

Science Alert  November 24, 2020 Researchers at the Los Alamos National Laboratory used Fast On-Orbit Detection of Transient Events (FORTE) satellite observations to identify superbolt-class optical lightning events and evaluate their origins. Superbolts have been defined as lightning pulses whose peak optical power exceeds 1011 W. However, it has been unclear whether superbolts resulted from particular types of high-energy lightning process or whether they were the result of measurement bias. According to their 12-year analysis of FORTE superbolt detections indicates that the lower optical superbolt energy range (~100 GW) is dominated by normal lightning, but brighter cases are predominantly strong […]

Shift in atmospheric rivers could affect Antarctic sea ice, glaciers

Science Daily  November 23, 2020 Researchers at UCLA investigated the atmospheric river (AR) frequency trends over the Southern Hemisphere using three reanalyses and two Community Earth System Model (CESM) ensembles. Their results show that AR frequency has been increasing over the Southern Ocean and decreasing over lower latitudes in the past four decades and that ARs have been shifting poleward. While the observed trends are mostly driven by the poleward shift of the westerly jet, the experiments indicate anthropogenic forcing would result in positive AR frequency trends over the Southern Ocean due mostly to moisture changes. They conclude that the […]

Artificial intelligence reveals hundreds of millions of trees in the Sahara

EurekAlert  October 20, 2020 A large proportion of dryland trees and shrubs grow in isolation, without canopy closure. These non-forest trees have a crucial role in biodiversity, and provide ecosystem services such as carbon storage, food resources and shelter for humans and animals. An international team of researchers (Denmark, USA – NASA Goddard Space Flight Center, Germany, France, Senegal, Belgium) mapped the crown size of each tree more than 3 m in size over a land area that spans 1.3 million km in the West African Sahara, Sahel and sub-humid zone. They detected over 1.8 billion individual trees. Although the […]

Volcanic ash may have a bigger impact on the climate than we thought

Science Daily  September 11, 2020 After the Mt. Kelut eruption in 2014 on the island of Java, stratospheric ash-rich aerosols were observed for months. A team of researchers in the US (University of Colorado, NOAA, industry) shows that the persistence of super-micron ash is consistent with a density near 0.5 g cm−3, close to pumice. Ash-rich particles dominate the volcanic cloud optical properties for the first 60 days. They found that the initial SO2 lifetime is determined by SO2 uptake on ash, rather than by reaction with OH as commonly assumed. About 43% more volcanic sulfur is removed from the stratosphere in […]

Developing models to predict storm surges

Science Daily  September 8, 2020 To develop the models researchers at the University of Central Florida linked large-scale climate variability events, such as El Niño, to variability in storm surge activity. They tested the models by having them predict past storm surge variability and compared their predictions with what actually occurred. The results indicated that the models matched the overall trends and variability of storm surge indicators for almost all coastal regions of the U.S during both the tropical and extra-tropical storm seasons. According to the researchers there is some capability in predicting storm surge variability over inter-annual to decadal […]