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An outstanding example of cooperation between Arctic and non-Arctic countries in cryosphere and climate research: Sino-Finnish cooperation for more than 30 years
Full text linkThe cryosphere is interconnected with other components of the climate system through global exchange of water, energy, and carbon. Long-term sustainable and pragmatic scientific and technological cooperation on the cryosphere and climatology in polar and sub-polar regions between China and Finland began in the 1980s. The fields of bilateral cooperation include joint training of young scientists, joint field observations, climatological and ecological researches of polar and sub-polar sea ice, glaciers and frozen lakes, etc. The year 2020 marked the 70th anniversary of the establishment of diplomatic relations between China and Finland. In order to celebrate the great achievements by Chinese and Finnish scientists in the fields of cryosphere and climate research, the Advances in Polar Science invited scientists from both sides to jointly organize a Special Issue entitled “Sino-Finnish cooperation on cryosphere and climatology in polar and sub-polar regions”. In this Special Issue, we have collected 10 papers, with most papers created jointly by scientists of both sides. The fruitful scientific achievement is strongly benefited from the sustainability of cooperation. Monitoring, research, prediction, mitigation, and adaptation to the climate change in the polar and sub-polar regions will definitively stay in the focus for many decades to come. A new era of Finnish-Chinese scientific collaboration on cryosphere has begun
The rise of sea ice research collaboration between China and Finland
Full text linkCollaboration between China and Finland in marine sciences was commenced in winter 1988. The main topic was then short-term sea ice forecasting in the seasonal sea ice zone (SSIZ), particularly in the Bohai Sea in China and the Baltic Sea in Finland. The sea ice in SSIZ is thin and highly dynamic so that ice conditions may change rapidly. While the length scales of the Baltic Sea and the Bohai Sea are similar, the main difference between them is that the former is brackish and non-tidal while the latter is oceanic for the salinity and possesses a large tidal amplitude. The Bohai Sea is located at latitudes 37°N–41°N, and the Baltic Sea is located at latitudes 55°N–66°N. However, the same sea ice model is applicable for both. The main application field of sea ice forecasting was winter shipping in Finland and oil drilling in China. The collaboration was successful and in late 1990s the research was expanded to polar seas, lakes, and to climate change applications
Observation and modelling of snow and sea ice mass balance and its sensitivity to atmospheric forcing during spring and summer 2007 in the Central Arctic
Full text linkSnow depth and sea ice thickness were observed applying an ice mass balance buoy (IMB) in the drifting ice station Tara during the International Polar Year in 2007. Detailed in situ observations on meteorological variables and surface fluxes were taken during May to August. For this study, the operational analyses and short-term forecasts from two numerical weather prediction (NWP) models (ECMWF and HIRLAM) were extracted for the Tara drift trajectory. We compared the IMB, meteorological and surface flux observations against the NWP products, also applying a one-dimensional thermodynamic sea ice model (HIGHTSI) to calculate the snow and ice mass balance and its sensitivity to atmospheric forcing. The modelled snow depth time series, controlled by NWP-based precipitation, was in line with the observed one. HIGHTSI reproduced well the snowmelt onset, the progress of the melt, and the first date of snow-free conditions. HIGHTSI performed well also in the late August freezing season. Challenges remain to model the “false bottom” observed during the melting season. The evolution of the vertical temperature profiles in snow and ice was better simulated when the model was forced by in situ observations instead of NWP results. During the melting period, the nonlinear ice temperature profile was successfully modelled with both forcing options. During spring and the melting season, total sea ice mass balance was most sensitive to uncertainties in NWP results for the downward longwave radiation, followed by the downward shortwave radiation, air temperature, and wind speed
The role of lake heat flux in the growth and melting of ice
Full text linkFor shallow lakes, ice mass balance is largely dominated by thermodynamic processes. The heat flux from lake water plays a critical role for ice growth and melting. In this study, we applied a numerical thermodynamic lake model to investigate the sensitivity of the lake ice mass balance to the lake heat flux during the growth and melting periods. Several groups of modelling experiments forced by simplified climatological weather data have been carried out. Two sites, Lake Wuliangsuhai in Inner Mongolia, China’s arid region and Lake Orajärvi in snowy Finnish Lapland, were investigated. Lake heat flux affects inversely proportional maximum ice thickness followed by ice break-up date. The solar radiation and surface albedo complicate the effect of lake heat flux on lake ice mass balance during melting season. With heavy snowfall, the increase of lake heat flux adds on the formation of granular ice but reduces the formation of columnar ice. Under climatological weather conditions, the ice cover winter seasonal mean lake heat flux were 14 W·m−2 and 4 W·m−2 in Lake Wuliangsuhai and Lake Orajärvi, respectively
Physics of Arctic landfast sea ice and implications on the cryosphere: an overview
Full text linkLandfast sea ice (LFSI) is a critical component of the Arctic sea ice cover, and is changing as a result of Arctic amplification of climate change. Located in coastal areas, LFSI is of great significance to the physical and ecological systems of the Arctic shelf and in local indigenous communities. We present an overview of the physics of Arctic LFSI and the associated implications on the cryosphere. LFSI is kept in place by four fasten mechanisms. The evolution of LFSI is mostly determined by thermodynamic processes, and can therefore be used as an indicator of local climate change. We also present the dynamic processes that are active prior to the formation of LFSI, and those that are involved in LFSI freeze-up and breakup. Season length, thickness and extent of Arctic LFSI are decreasing and showing different trends in different seas, and therefore, causing environmental and climatic impacts. An improved coordination of Arctic LFSI observation is needed with a unified and systematic observation network supported by cooperation between scientists and indigenous communities, as well as a better application of remote sensing data to acquire detailed LFSI cryosphere physical parameters, hence revolving both its annual cycle and long-term changes. Integrated investigations combining in situ measurements, satellite remote sensing and numerical
modeling are needed to improve our understanding of the physical mechanisms of LFSI seasonal changes and their impacts on the environment and climate
Finland's Strategy for Arctic Policy
Full text linkFinland’s new Arctic policy strategy sets out Finland’s key objectives in the Arctic region. All activities in the Arctic region must be based on ecological carrying capacity, climate protection, principles of sustainable development, and respect for the rights of indigenous peoples. The objectives arising from Finland’s economic interests can also be examined from this perspective. The strategy extends to the year 2030
Different physiopsychological changes between AMSsusceptible and AMS-resistant pre-selected Antarctic expeditioners in Tibet
Full text linkThrough dynamically monitoring changes of acute mountain sickness (AMS) occurrences, cardiopulmonary function and mood states from Shanghai (4 m) to Lhasa (3650 m) and Yambajan (4300 m), Tibet, we obtained physiopsychological data of the 37th Chinese Antarctic pre-selected expeditioners for Kunlun Station. Through analyzing different physiopsychological changes between AMS-susceptible (AMS-S) and AMS-resistant (AMS-R) expeditioners, we would explore indicators to screen hypoxia-susceptible expeditioners. According to AMS occurrences evaluated by Lake Louise Score (LLS) in Yambajan, we divided the expeditioners (n=24, 31.92±5.76 a) into AMS-S and AMS-R groups. Using a series of medical instruments and questionnaires, we monitored their cardiopulmonary function and mood states, and analyzed the differences of physiopsychological parameters between AMS-S and AMS-R groups. Compared with Shanghai, when expeditioners arrived in Yambajan, in both AMS-S and AMS-R groups, oxygen saturation (SpO2) significantly decreased, and blood pressure significantly increased (P<0.05). As for electrocardiogram (ECG), interval from the beginning to the end of QRS complex wave (QRS), interval from the beginning of QRS complex wave to the end of T wave (QT), interval between 2 adjacent P waves (PP) and interval between 2 adjacent R waves (RR) significantly decreased, heart rate (HR) and HR-corrected QT interval (QTc) significantly increased (P<0.05). Cardiac contractility and pumping function significantly decreased, systemic vascular resistance significantly increased (P<0.05). Pulmonary airway patency significantly increased (P<0.05). Compared with AMS-R group, AMS-S group showed significantly lower SpO2 and higher stroke volume variation (SVV) in Shanghai, however, significantly lower maximal expiratory flow at 75% of forced vital capacity (MEF75), higher levels of anxiety, fatigue and confusion in Yambajan (P<0.05). In conclusion, when expeditioners arrived at 4300 m, their cardiopulmonary function and mood states changed significantly. SpO2, SVV, MEF75, anxiety, fatigue and confusion maybe could be used as clues for screening hypoxia-susceptible individuals
An observational study of precipitation types in the Alaskan Arctic
Full text linkThe effects of various precipitation types, such as snow, rain, sleet, hail and freezing rain, on regional hydrology, ecology, snow and ice surfaces differ significantly. Due to limited observations, however, few studies into precipitation types have been conducted in the Arctic. Based on the high-resolution precipitation records from an OTT Parsivel2 disdrometer in Utqiaġvik, Alaska, this study analysed variations in precipitation types in the Alaskan Arctic from 15 May to 16 October, 2019. Results show that rain and snow were the dominant precipitation types during the measurement period, accounting for 92% of the total precipitation. In addition, freezing rain, sleet, and hail were also observed (2, 4 and 11 times, respectively), accounting for the rest part of the total precipitation. The records from a neighbouring U.S. Climate Reference Network (USCRN) station equipped with T-200B rain gauges support the results of disdrometer. Further analysis revealed that Global Precipitation Measurement (GPM) satellite data could well characterise the observed precipitation changes in Utqiaġvik. Combined with satellite data and station observations, the spatiotemporal variations in precipitation were verified in various reanalysis datasets, and the results indicated that ECMWF Reanalysis v5 (ERA5) could better describe the observed precipitation time series in Utqiaġvik and the spatial distribution of data in the Alaskan Arctic. Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) overestimated the amount and frequency of precipitation. Japanese 55-year Reanalysis (JRA-55) could better simulate heavy precipitation events and the spatial distribution of the precipitation phase, but it
overestimated summer snowfall
IDA Proceedings - 8th Biennial Symposium on the Impacts of an Ice-Diminishing Arctic on Naval and Maritime Operations
Full text linkOn July 17 and 18, 2019, the U.S. Arctic Research Commission, U.S. National Ice Center, and Wilson Center’s Polar Institute hosted the 8th Biennial Symposium on the Impacts of an Ice-Diminishing Arctic on Naval and Maritime Operations—abbreviated to IceDiminishing Arctic or “IDA.” The Polar Institute is pleased to summarize the topics of each speaker’s presentation in these proceedings
