Earth’s ‘third pole’ and its role in global climate

Phys.org  August 25, 2023 Researchers in China reviewed recent advances in research regarding land–atmosphere coupling processes over the Tibetan Plate (TP) and concluded that climate warming has caused glacier retreat, permafrost degradation, and a general increase in vegetation density, while climate wetting has led to a significant increase in the number of major lakes, primarily through increased precipitation. The TP drives surface pollutants to the upper troposphere in an Asian summer monsoon (ASM) anticyclone circulation before spreading to the lower stratosphere. The thermal forcing of the TP plays an essential role in the ASM. TP forcing can modulate hemispheric-scale atmospheric […]

Researchers take aim at weather forecasters’ biggest blind spot

Phys.org  August 29, 2023 A team of researchers in the US (Stevens Institute of Technology, NOAA) evaluated spatiotemporal variability of deterministic and probabilistic precipitation nowcasting models’ performance over the greater New York City area. They assessed five deterministic and two probabilistic nowcasting methods using Multi-Radar Multi-Sensor data from 2014 to 2022. Three lead times of 2, 4 and 6 h were considered. LINDA-P had the best average Pearson’s correlation of 0.87 at the first step and 0.47 at the last one and the longest 80 min average decorrelation times. Its Mean Absolute Error (MAE) was four times lower in winter […]

Effect of volcanic eruptions significantly underestimated in climate projections

Science Daily  June 23, 2023 Standard climate projections, as in Intergovernmental Panel on Climate Change Sixth Assessment Report, assume that explosive volcanic activity over 2015–2100 are of the same level as the 1850–2014 period. Researchers in the UK used the latest ice-core and satellite records to design stochastic eruption scenarios, to show that there is a 95% probability that explosive eruptions could emit more sulfur dioxide (SO2) into the stratosphere over 2015–2100 than current standard climate projections (i.e., ScenarioMIP). Their simulations using the UK Earth System Model with interactive stratospheric aerosols showed that for a median future eruption scenario, the […]

Study of Earth’s stratosphere reduces uncertainty in future climate change

Phys.org  June 26, 2023 Future increases in stratospheric water vapour risk amplifying climate change and slowing down the recovery of the ozone layer. Uncertainty in modeling primarily arises from the complex processes leading to dehydration of air during its tropical ascent into the stratosphere. An international team of researchers (UK, USA – NOAA, University of Colorado, Switzerland, Germany) used a statistical-learning approach to infer historical co-variations between the atmospheric temperature structure and tropical lower stratospheric water vapour concentrations. They demonstrated that these historically constrained relationships are predictive of the water vapour response to increased atmospheric carbon dioxide and obtained an […]

Lake water storage on Inner Tibetan Plateau increases under climate change, finds study

Phys.org  April 10, 2023 Lakes store 20% of surface freshwater resources and are an important link for studying the interactions between the various spheres of the Earth system. There are approximately 1400 lakes larger than 1 km2 on the Tibetan Plateau (TP), with a total area of approximately 50,000 km2, accounting for half of the number and area of lakes in China. Researchers in China estimated lake water storage anomalies (LWSA) of 18 lakes (area greater than 300 km2) during 2002–2018 on the Inner TP. They projected future changes of LWSA for an intermediate scenario based on an artificial neural […]

New method for fast, efficient and scalable cloud tomography

Phys.org  March 28, 2023 One way to study clouds is to use spaceborne imagers, but these imagers still face challenges of efficiency and scalability. Researchers in Israel have developed an effective inverse rendering framework for recovering the 3D distribution of clouds. They focused on clouds which have a key role in the climate system and require efficient analysis at a huge scale. Data for such reconstruction are multiview images of each cloud taken simultaneously. This acquisition mode is expected by upcoming future spaceborne imagers, such as Cloud Computed Tomography (CT). Prior art showed that scattering CT can rely on Monte–Carlo […]

Third pole darkening affects local and remote climates, finds study

Phys.org  March 28, 2023 Despite knowledge of the presence of the Tibetan Plateau (TP) in reorganizing large-scale atmospheric circulation, it remains unclear how surface albedo darkening over TP will impact local glaciers and remote Asian monsoon systems. An international team of researchers (USA – Columbia University, Austria, Germany, France) used a coupled land-atmosphere global climate model and a glacier model to address these questions. According to their model, under a high-emission scenario, TP surface albedo darkening would increase local temperature by 0.24 K by the end of this century. This warming would strengthen the elevated heat pump of TP, increasing South […]

Underused satellite, radar data may improve thunderstorm forecasts

Science Daily  March 9, 2023 Many of the processes necessary for daytime convection initiation (CI) are rooted in the planetary boundary layer (PBL), which numerical models struggle to accurately predict. To improve ensemble forecasts of the PBL and subsequent CI forecasts in CAM ensembles, researchers at Pennsylvania State University explored the use of underused data from both the GOES-16 satellite and the national network of WSR-88D radars. The GOES-16 satellite provides observations of brightness temperature (BT) to better analyze cloud structures, while the WSR-88D radars provide PBL height estimates and clear-air radial wind velocity observations to better analyze PBL structures. […]

Fickle winters in East Asia caused by major shift in regional atmospheric circulation, suggests study

Phys.org  February 27, 2023 Researchers in Japan investigated the structure and dynamics of two distinct patterns. They showed that the winter climate over East Asia is influenced by two teleconnection patterns, the western Pacific pattern, and the Southeast Asia-Japan pattern. Using meteorological data for winters from 1974 to 2021 they established the baseline climate and analyzed anomalous departures from that baseline. In the first half of the 2020/2021 winter season, an anticyclonic circulation anomaly appeared over the southeastern Tibetan Plateau, and a corresponding cyclonic anomaly occurred over northern Japan. This pattern was associated with enhanced convection over the South China […]

New technology revolutionizes the analysis of old ice

Science Daily  February 16, 2023 The objective of EPICA [European Project for Ice Coring in Antarctica] is to look back 1.5 million years into the past and obtain data on the development of temperature, the composition of the atmosphere and the carbon cycle. A depth of around 2700 meters must be reached in the Antarctic ice sheet and an ice core recovered which they plan to accomplish by 2025. In the 1.5-million-year-old ice, 15,000 to 20,000 years of climate history are compressed into just one meter of ice core, which places completely new demands on ice core analyzes. Researchers in […]