Supplementary material to "The ERA5-Land Soil-Temperature Bias in Permafrost Regions"

Abstract. ERA5-Land (ERA5L) is a reanalysis product derived by running the land component of ERA5 at increased resolution. This study evaluates ERA5L soil temperature in permafrost regions based on observations and published permafrost products. We find that ERA5L overestimates soil temperature in northern Canada and Alaska but underestimates it in mid–low latitudes, leading to an average bias of −0.08 ∘C. The warm bias of ERA5L soil is stronger in winter than in other seasons. As calculated from its soil temperature, ERA5L overestimates active-layer thickness and underestimates near-surface (<1.89 m) permafrost area. This is thought to be due in part to the shallow soil column and coarse vertical discretization of the land surface model and to warmer simulated soil. The soil temperature bias in permafrost regions correlates well with the bias in air temperature and with maximum snow height. A review of the ERA5L snow parameterization and a simulation example both point to a low bias in ERA5L snow density as a possible cause for the warm bias in soil temperature. The apparent disagreement of station-based and areal evaluation techniques highlights challenges in our ability to test permafrost simulation models. While global reanalyses are important drivers for permafrost simulation, we conclude that ERA5L soil data are not well suited for informing permafrost research and decision making directly. To address this, future soil temperature products in reanalyses will require permafrost-specific alterations to their land surface models.

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The ERA5-Land Soil-Temperature Bias in Permafrost Regions

10.5194/tc-2020-76 ◽

2020 ◽

Author(s):

Bin Cao ◽

Stephan Gruber ◽

Donghai Zheng ◽

Xin Li

Keyword(s):

Soil Temperature ◽

Layer Thickness ◽

Active Layer ◽

Active Layer Thickness ◽

Near Surface ◽

Average Bias ◽

Warm Bias ◽

Temperature Bias ◽

Low Latitudes ◽

Permafrost Regions

Abstract. ERA5-Land (ERA5L) is a reanalysis product derived by running the land component of ERA5 at increased resolution. This study evaluates its soil temperature in permafrost regions based on observations and published permafrost products. Soil in ERA5L is predicted too warm in northern Canada and Alaska, but too cold in mid-low latitudes, leading to an average bias of −0.08 °C. The warm bias of ERA5L soil is stronger in winter than in other seasons. Diagnosed from its soil temperature, ERA5L overestimates active-layer thickness and underestimates near-surface (

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Review "The ERA5-Land Soil-Temperature Bias in Permafrost Regions"

10.5194/tc-2020-76-rc1 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Soil Temperature ◽

Temperature Bias ◽

Permafrost Regions

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Supplementary material to "Evaluation of air-soil temperature relationships simulated by land surface models during winter across the permafrost region"

10.5194/tc-2016-36-supplement ◽

2016 ◽

Author(s):

Wenli Wang ◽

Annette Rinke ◽

John C. Moore ◽

Duoying Ji ◽

Xuefeng Cui ◽

...

Keyword(s):

Soil Temperature ◽

Land Surface ◽

Permafrost Region ◽

Land Surface Models ◽

Surface Models ◽

Supplementary Material

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Contribution of the nongrowing season to annual N<sub>2</sub>O emissions from the continuous permafrost region in Northeast China

10.5194/bg-2020-305 ◽

2020 ◽

Author(s):

Weifeng Gao ◽

Dawen Gao ◽

Liquan Song ◽

Houcai Sheng ◽

Tijiu Cai ◽

...

Keyword(s):

Soil Temperature ◽

Climate Warming ◽

Growing Season ◽

N2o Emission ◽

N2o Emissions ◽

Permafrost Region ◽

Carbon And Nitrogen ◽

Annual Budget ◽

The Mean ◽

Permafrost Regions

Abstract. Permafrost regions store large amounts of soil organic carbon and nitrogen, which are major sources of greenhouse gas. With climate warming, permafrost regions are thawing, releasing an abundance of greenhouse gases to the atmosphere and contributing to climate warming. Numerous studies have shown the mechanism of nitrous oxide (N2O) emissions from the permafrost region during the growing season. However, little is known about the temporal pattern and drivers of nongrowing season N2O emissions from the permafrost region. In this study, N2O emissions from the permafrost region were investigated from June 2016 to June 2018 using the static opaque chamber method. Our aims were to quantify the seasonal dynamics of nongrowing season N2O emissions and its contribution to the annual budget. The results showed that the N2O emissions ranged from −35.75 to 74.16 μg·m−2·h−1 during the nongrowing season in the permafrost region. The mean N2O emission from the growing season were 1.75–2.86 times greater than that of winter and 1.31–1.53 times greater than that of spring thaw period due to the mean soil temperature of the different specified periods. The nongrowing season N2O emissions ranged from 0.89 to 1.44 kg ha−1, which contributed to 41.96–53.73 % of the annual budget, accounting for almost half of the annual emissions in the permafrost region. The driving factors of N2O emissions were different among during the study period, growing season, and nongrowing season. The N2O emissions from total two-year observation period and nongrowing season were mainly affected by soil temperature, while the N2O emissions from growing season were controlled by soil temperature, water table level, and their interactions. In conclusion, nongrowing season N2O emissions is an important component of annual emissions and cannot be ignored in the permafrost region.

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Influence of seasonal soil temperature variation and global warming on the seismic response of frozen soils in permafrost regions

Earthquake Engineering & Structural Dynamics ◽

10.1002/eqe.3536 ◽

2021 ◽

Author(s):

Jamin Park ◽

Oh‐Sung Kwon ◽

Luigi Di Sarno

Keyword(s):

Global Warming ◽

Soil Temperature ◽

Seismic Response ◽

Temperature Variation ◽

Frozen Soils ◽

Permafrost Regions

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Establishment and Application of the Pipeline Monitoring System in Permafrost Regions in China

Volume 2: Pipeline Safety Management Systems; Project Management, Design, Construction, and Environmental Issues; Strain Based Design; Risk and Reliability; Northern, Offshore, and Production Pipelines ◽

10.1115/ipc2020-9547 ◽

2020 ◽

Author(s):

Jianping Liu ◽

Pengchao Chen ◽

Hong Zhang ◽

Baodong Wang ◽

Xiaoben Liu

Keyword(s):

Temperature Field ◽

Soil Temperature ◽

Monitoring System ◽

Field Monitoring ◽

Measurement Unit ◽

Displacement Monitoring ◽

Ground Displacement ◽

Oil Pipeline ◽

Strain Monitoring ◽

Permafrost Regions

Abstract Buried pipelines in permafrost regions are inevitably subjected to some typical geohazards, such as frost heave, thaw settlement and thaw slumping. The bending or/and longitudinal strains will be induced in pipe under these types ground movement, which is the potential cause of weld joint rupture. Thus, in order to prevent pipe failure, a comprehensive monitoring system was designed and used in the Mohe-Daqing oil pipeline in the permafrost region in northeast China. The Mohe-Daqing oil pipeline is built for importing oil from Russia and its north part of 440km lays in permafrost. The monitoring system includes soil temperature field monitoring system, ground displacement monitoring system and pipe strain monitoring system. The soil temperature field monitoring system, which uses fiber brag grating sensors, can monitor the distribution of surrounding soil temperature in radial direction of pipe in order to detect the change of active ring of permafrost. The ground displacement monitoring system, which is based on a total station, can discover any subsidence or heave of the pipe itself and the embankment along the pipeline. The pipe strain monitoring system, which includes pipe stress monitoring system based on fiber brag grating sensors and inertial measurement unit (IMU) mapping, can inspect the real-time change of pipe stress and the bending strain periodically respectively. Using the comprehensive monitoring system, the important parameters that affect pipeline integrity such as pipeline temperature, stress, strain and displacement of Mohe-Daqing oil pipeline can be supervised timely and effectively. And the accuracy and reliability of the monitoring system have been verified in practical application. In this paper, detail about how these systems are designed and installed on the Mohe-Daqing oil pipeline is elucidated and the monitoring data is analyzed. Through these data, the present mechanical situation of Mohe-Daqing oil pipeline is safe, but the long-term change is critical because of the soaring oil temperature that is far high than the design temperature. The monitoring system is of great significance to ensure the safe operation of Mohe-Daqing pipeline and can provide reference for the pipeline operation in permafrost areas.

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Assessing the simulated soil hydrothermal regime of the active layer from the Noah-MP land surface model (v1.1) in the permafrost regions of the Qinghai–Tibet Plateau

Geoscientific Model Development ◽

10.5194/gmd-14-1753-2021 ◽

2021 ◽

Vol 14 (3) ◽

pp. 1753-1771

Author(s):

Xiangfei Li ◽

Tonghua Wu ◽

Xiaodong Wu ◽

Jie Chen ◽

Xiaofan Zhu ◽

...

Keyword(s):

Soil Temperature ◽

Snow Cover ◽

Land Surface ◽

Tibet Plateau ◽

Cold Bias ◽

Surface Model ◽

Model Parameters ◽

Hydrothermal Regime ◽

Qinghai Tibet Plateau ◽

Permafrost Regions

Abstract. Extensive and rigorous model intercomparison is of great importance before model application due to the uncertainties in current land surface models (LSMs). Without considering the uncertainties in forcing data and model parameters, this study designed an ensemble of 55 296 experiments to evaluate the Noah LSM with multi-parameterization (Noah-MP) for snow cover events (SCEs), soil temperature (ST) and soil liquid water (SLW) simulation, and investigated the sensitivity of parameterization schemes at a typical permafrost site on the Qinghai–Tibet Plateau (QTP). The results showed that Noah-MP systematically overestimates snow cover, which could be greatly resolved when adopting the sublimation from wind and a semi-implicit snow/soil temperature time scheme. As a result of the overestimated snow, Noah-MP generally underestimates ST, which is mostly influenced by the snow process. A systematic cold bias and large uncertainties in soil temperature remain after eliminating the effects of snow, particularly in the deep layers and during the cold season. The combination of roughness length for heat and under-canopy (below-canopy) aerodynamic resistance contributes to resolving the cold bias in soil temperature. In addition, Noah-MP generally underestimates top SLW. The runoff and groundwater (RUN) process dominates the SLW simulation in comparison to the very limited impacts of all other physical processes. The analysis of the model structural uncertainties and characteristics of each scheme would be constructive to a better understanding of the land surface processes in the permafrost regions of the QTP as well as to further model improvements towards soil hydrothermal regime modeling using LSMs.

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