Carbon Emissions under Arctic Snow (CEAS)

北极雪下的碳排放（CEAS）

• 批准号: NE/W003686/1
• 负责人: Nick Rutter
• 金额: $ 10.65万
• 依托单位: Northumbria University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW003686%2F1
• 关键词: Carbon; Emissions; under; Arctic; Snow

Until recently, awareness of the importance of winter carbon dioxide emissions from arctic soils was highly limited, resulting from incorrect assumptions that emissions from frozen soils beneath snow were insignificant compared to other sources. Consequently, carbon dioxide emissions during arctic winter months are frequently omitted from global carbon cycling budgets and our capacity to measure atmosphere-snow-soil processes controlling carbon dioxide emission and simulate them in climate models are under-developed. This limits our ability to make future climate projections, especially in arctic tundra and forested regions, which characterise about 27% of the Earth's land surface and are warming more than twice as fast as the global average since the late twentieth century.Carbon dioxide, a gas which causes the Earth's atmosphere to trap heat causing the planet to warm, is emitted by microbes decomposing organic material in soil. Decomposition can occur when the soil is frozen, but rates of carbon dioxide emission decrease as soil temperatures decrease, down to -20 degrees Celsius when carbon dioxide emissions become negligible. Winter snow cover has an important impact on arctic soil temperatures, acting like a duvet covering a bed. A thick duvet with lots of air trapped between the feathers provides insulation. Air trapped between the snow crystals within a snowpack acts in a similar manner, limiting the loss of heat from soils warmed in the summer to the cold atmosphere during long arctic winters. As the ground is often snow covered for at least half of the year in Arctic regions, it is vital that we understand processes that control the impact of snow cover on soil temperatures and carbon dioxide emissions, and accurately represent these processes in climate models. Here we ask, how sensitive are measured carbon dioxide concentrations within arctic snowpacks to the variability of snowpack physical properties (e.g. size of the snow crystals)? Can more realistic simulations of snowpack density and thermal conductivity in climate models reduce the underprediction in carbon dioxide emissions from arctic snowpacks? And, how may future changes in winter soil temperatures and snow cover affect future carbon dioxide emissions? In order to answer these questions, we will create a new field measurement database of arctic meteorology, soil and snow properties, and carbon dioxide concentrations. We will use this database to develop more realistic representations of processes controlling winter carbon dioxide emissions in climate models, which will lead to confident model projections of future winter carbon dioxide emissions from the wider Arctic region. By combining field and laboratory measurements with climate modelling, this partnership between Canadian, Finnish and UK scientists will increase our predictive understanding of Arctic environmental change resulting from, and contributing to, our warming planet.

直到最近，人们对北极土壤冬季二氧化碳排放重要性的认识还非常有限，因为人们错误地认为雪下冻土的排放量与其他来源相比微不足道。因此，北极冬季的二氧化碳排放经常被忽略在全球碳循环预算中，而我们测量控制二氧化碳排放的大气-雪-土壤过程以及在气候模型中模拟它们的能力也不够发达。这限制了我们做出未来气候预测的能力，特别是在北极苔原和森林地区，这些地区约占地球陆地表面的 27%，自 20 世纪末以来变暖速度是全球平均水平的两倍以上。导致地球大气层滞留热量导致地球变暖的气体是由微生物分解土壤中的有机物质所排放的。当土壤冻结时会发生分解，但二氧化碳排放率随着土壤温度降低而降低，当二氧化碳排放量可以忽略不计时，二氧化碳排放率会降低至-20摄氏度。冬季积雪对北极土壤温度有重要影响，就像覆盖床上的羽绒被一样。羽毛之间存有大量空气的厚羽绒被可起到隔热作用。积雪内雪晶之间的空气也以类似的方式起作用，限制了夏季变暖的土壤向北极漫长冬季寒冷大气的热量损失。由于北极地区的地面通常至少有半年被积雪覆盖，因此我们了解控制积雪对土壤温度和二氧化碳排放影响的过程，并在气候模型中准确地表示这些过程至关重要。在这里我们要问，北极积雪内测量的二氧化碳浓度对积雪物理特性（例如雪晶体的大小）的变化有多敏感？在气候模型中对积雪密度和热导率进行更真实的模拟能否减少对北极积雪二氧化碳排放量的低估？而且，冬季土壤温度和积雪的未来变化将如何影响未来的二氧化碳排放？为了回答这些问题，我们将创建一个新的北极气象、土壤和雪特性以及二氧化碳浓度的现场测量数据库。我们将使用该数据库来开发气候模型中控制冬季二氧化碳排放过程的更真实的表示，这将有助于对更广泛的北极地区未来冬季二氧化碳排放量进行可靠的模型预测。通过将现场和实验室测量与气候模型相结合，加拿大、芬兰和英国科学家之间的这种合作将增加我们对由地球变暖造成的北极环境变化的预测性了解。

项目成果

Environmental controls of winter soil carbon dioxide fluxes in boreal and tundra environments

• DOI: 10.5194/bg-20-5087-2023
• 发表时间: 2023-12-20
• 期刊: BIOGEOSCIENCES
• 影响因子: 4.9
• 作者: Mavrovic，Alex;Sonnentag，Oliver;Roy，Alexandre
• 通讯作者: Roy，Alexandre

Impact of measured and simulated tundra snowpack properties on heat transfer

测量和模拟的苔原积雪特性对传热的影响

• DOI: 10.5194/tc-16-4201-2022
• 发表时间: 2022
• 期刊: The Cryosphere
• 作者: Dutch V

Supplementary material to "Simulating net ecosystem exchange under seasonal snow cover at an Arctic tundra site"

“模拟北极苔原地区季节性积雪下的净生态系统交换”的补充材料

• DOI: 10.5194/egusphere-2023-772-supplement
• 发表时间: 2023
• 作者: Dutch V

Impact of variability in measured and simulated tundra snowpack properties on heat transfer metrics

测量和模拟的苔原积雪特性的变化对传热指标的影响

• DOI: 10.5194/egusphere-egu21-1319
• 发表时间: 2021
• 作者: Dutch V