Conference Agenda

Abstract: The Northern China was hit by a severe dust storm on March 15, 2021, involving a large range and affecting a deep degree, which was unprecedented in more than a decade. In the study, we carried out a day and night continuous monitoring of the dust storm path, using multi spectral data from the Chinese FY-4A satellite combined with the Japanese Himawary-8 from the visible to near-infrared, mid-infrared and far-infrared band. We monitored .the whole process of the dust storm from the occurrence, developed, transportation and extinction. The HYSPLIT backward tracking results show two main dust sources: one is the west of Mongolian Republic, and the other is western Inner Mongolia Gobi and Ordos and other areas. Analysis shows that the preconditioning and favourable weather conditions were the main reason for the severe dust storm. Continuous high temperature without precipitation in early period led to abundant sources of sand and dust over the west of Mongolia and Inner Mongolia. On March 14-15, strong winds behind the Mongolian cyclone blew a great deal of dust into the air and they were transported over a long distance by the cyclone, resulting in the strong dust storm, which severely affected the vast area of northern China. The strong dust storm occurred under the background of significantly increase frequency and intensity of extreme weather over northern China in recent years, which may be related to the development of global climate change.

Figure 1 shows the process of dust blowing into the air, transportation and developed into dust storm in Mongolia on March 14, 2021.

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Fig1. Monitoring of the process of sand blowing into the air, transportation and developed into dust storm in Mongolia on March 14, 2021.

Figure 2 show the process of dust storm moved towards China and arrived in Beijing at 21:00 March 14, 2021.

Fig2. Monitoring of the process of dust storm moved towards China and arrived in Beijing at 21:00 March 14, 2021.

At the same time of about 22:00 March 14,2021, events of sand and storm blowing into the air occurred from the Hexi corridor, to the western inner Mongolia Gobi and Ordos, and the great deal of dust storm was transported east ward by strong wind behind the Mongolian cyclone, arrived in Beijing at 2:00 March 15 and affected the atmosphere combined with these from Mongolia.

Fig 3. Monitoring of dust storm from the Hexi corridor and western inner Mongolia Gobi and Ordos arrived in Beijing, and affect the atmosphere combined with these from Mongolia.

From 4:00 to 6:00 on March 15, 2021, dust from Mongolia and west China jointly formed the strong dust storm over northern China.

Fig 4. Monitoring the forming of strong dust storm over northern China during 4:00 to 6:00 March 15, 2021.

Figure 5 show the whole process and path Mongolia and combined with the other source of west China, and formed the severe dust storm over northern China and finally disappeared over the Korean Peninsula and Japanese Sea. The whole process lasted more than 40 hours, and transported a distance of about 3900km with a mean speed of 95km per hour.

Fig 5. The process and path of the severe dust storm over northern China

Keywords: the FY-4A Satellite, the Himawary-8 satellite, dust storm, climate change

It is crucial to monitor and understand regional sea-level changes that can differ from Global Mean Sea Level (GMSL) both in terms of magnitude as well as governing forcing and mechanisms (Stammer et al., 2013). For instance, while changes in salinity can have significant distinct impact on regional sea level change, such as in the Arctic Ocean, it has minor effect on GMSL. Quantifying the natural variability in the regional sea level change is also urgent in order to distinguish it from a potentially forced (anthropogenic) signal. Furthermore, the role of remote impact of climate variability from one region to another needs to be well-understood. Natural climate variability in the Pacific Ocean can, for instance, impact the Arctic Amplification and thus the sea ice conditions (Li et al., 2015; Svendsen et al., 2018; Yang et al., 2020). The way in which this translates into sea level change, on the other hand, remains unclear. The aim of this study is to examine and relate the sea level variability of the Beaufort Gyre (BG) in the Arctic Ocean to natural climate variability of the Pacific Ocean.

We highlight results of three studies: The first study investigates the benefits of the reprocessed altimetry dataset at 5 Hz with augmented signal resolution to study the sea level variability of the Arctic and Nordic Seas (Bonaduce et al., 2021, in prep). In particular, we compare the ability of this dataset to improve the mesoscale details in the forecasts in comparison to the conventional altimetry sampling (1 Hz) dataset and to the altimetry-blind experiments (e.g. without assimilation of altimeter data), in order to assess the added value of the enhanced altimetry reprocessing as well as the assimilation of the high-resolution altimetry data in ocean re-analysis for the Arctic. The second study highlights the non-stationary nature of the Barents Sea SST response to ENSO (Chatterjee et al., 2021, to be submitted). The causal link is established via the ENSO-related changes in north Atlantic atmospheric circulation which modulate the East Atlantic Pattern (EAP) and thus the Atlantic Water intrusion and SST in the Barents Sea. The third study investigates the impact of Pacific Decadal Oscillation-like (hereafter PDO-like) SST anomaly on surface air temperature over the mid-to-high latitude Northern Hemisphere. After removing the ENSO’s signal, the PDO-like SST anomaly is related to the surface air temperature over northern Europe and the Chukchi Peninsula and Kamchatka Peninsula through changing the atmospheric circulations.

The Third Pole Environment centred on the Tibetan plateau and the Himalayas feeds Asia’s largest rivers which provide water to 1.5 billion people across ten countries. Due to its high elevation, TPE plays a significant role in global atmospheric circulation and is highly sensitive to climate change. Intensive exchanges of water and energy fluxes take place between the Asian monsoon, the plateau land surface (lakes, glaciers, snow and permafrost) and the plateau atmosphere at various temporal and spatial scales, but a fundamental understanding of the details of the coupling is lacking especially at the climate scale. Expanding westward from the Third Pole, the Pan-Third Pole region covers 20 million km², encompassing the Tibetan Plateau, Pamir, Hindu Kush, Iran Plateau, the Caucasians, the Carpathians, etc. and is home to over 3 billion people. Climate change is expected to dramatically impact the water and energy as well as carbon cycles and exchanges in the Pan-TPE area and consequently alter the water resources, food security, energy transition and ecosystems as well as other related societal challenges. Monitoring and modelling climate change in Pan-TPE reflect key societal issues and contribute to the science component to other international initiatives, e.g. UN sustainable development goals (SDG), GEO societal benefit areas and the ESA EO science for society strategy.

The objective of this CLIMATE-Pan-TPE project is: To improve the process understanding of the interactions between the Asian monsoon, the plateau surface (including its permafrost and lakes) and the Tibetan plateau atmosphere in terms of water, energy and carbon budgets; To assess and monitor changes in cryosphere and hydrosphere; and to model and predict climate change impacts on water resources and ecosystems in the Pan-Third Pole Environment.

A core innovation of the CLIMATE-Pan-TPE project is to verify or falsify recent climate change hypotheses (e.g. links between plateau heating and monsoon circulation, snow cover and monsoon strength, soil moisture and timing of monsoon) and projections of the changes of glaciers and permafrost in relation to surface and tropospheric heating on the Tibetan plateau as precursors of monsoon pattern changes and glaciers retreat, and their impacts on water resources and ecosystems.

Method: We will use earth observation, in-situ measurements and modelling to advance process understanding relevant to monsoon scale predictions, and improve and develop coupled regional scale observation and hydroclimatic models to explain different physical links and scenarios that cannot be observed directly.

Deliverables: The deliverables will be scientific outputs in terms of peer reviewed journal publications, PhD theses and data sets in terms of novel data records and modelling tools of essential climate variables for quantification of water, energy and carbon cycle dynamics in the Pan-Third Pole Environment.