Improved radio occultation sounding of the Arctic atmosphere using simulations with a high resolution atmospheric model

2004 ◽  
Vol 29 (2-3) ◽  
pp. 277-286 ◽  
Author(s):  
V. Kunitsyn ◽  
V. Zakharov ◽  
K. Dethloff ◽  
A. Weisheimer ◽  
M. Gerding ◽  
...  
Keyword(s):  
High Resolution ◽  
Radio Occultation ◽  
Atmospheric Model ◽  
The Arctic ◽  
Arctic Atmosphere

scholarly journals High-Resolution COSMO-CLM Modeling and an Assessment of Mesoscale Features Caused by Coastal Parameters at Near-Shore Arctic Zones (Kara Sea)

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1062
Author(s):  
Vladimir Platonov ◽  
Alexander Kislov
Keyword(s):  
High Resolution ◽  
Atmospheric Model ◽  
Atmospheric Modeling ◽  
Kara Sea ◽  
The Arctic ◽  
Small Scale ◽  
Mesoscale Circulation ◽  
Dynamic Features ◽  
Wind Speeds ◽  
Verification Methods

Coastal Arctic regions are characterized by severe mesoscale weather events that include extreme wind speeds, and the rugged shore conditions, islands, and mountain ranges contribute to mesoscale event formation. High-resolution atmospheric modeling is a suitable tool to reproduce and estimate some of these events, and so the regional non-hydrostatic climate atmospheric model COSMO-CLM (Consortium for Small-scale Modeling developed within the framework of the international science group CLM-Community) was used to reproduce mesoscale circulation in the Arctic coast zone under various surface conditions. Mid-term experiments were run over the Arctic domain, especially over the Kara Sea region, using the downscaling approach, with ≈12 km and ≈3 km horizontal grid sizes. The best model configuration was determined using standard verification methods; however, the model run verification process raised questions over its quality and aptness based on the high level of small-scale coastline diversity and associated relief properties. Modeling case studies for high wind speeds were used to study hydrodynamic mesoscale circulation reproduction, and we found that although the model could not describe the associated wind dynamic features at all scales using ≈3 km resolution, it could simulate different scales of island wind shadow effects, tip jets, downslope winds, vortex chains, and so on, quite realistically. This initial success indicated that further research could reveal more about the detailed properties of mesoscale circulations and extreme winds by applying finer resolution modeling.

scholarly journals Dynamical Heating of the Arctic Atmosphere during the Springtime Transition

2017 ◽  
Vol 30 (23) ◽  
pp. 9539-9553 ◽  
Author(s):  
Xiaoyu Long ◽  
Walter A. Robinson
Keyword(s):  
Baroclinic Instability ◽  
Stationary Wave ◽  
Atmospheric Model ◽  
Meridional Wind ◽  
Early Spring ◽  
Heat Fluxes ◽  
The Arctic ◽  
Global Atmospheric Model ◽  
Eddy Heat Flux ◽  
Arctic Atmosphere

The Arctic undergoes an abrupt transition from the quasi-steady climate of winter to a period of rapid warming in spring. To explore the atmospheric dynamics of this transition, an extended simulation using a global atmospheric model driven by a fixed repeating annual cycle of sea surface temperatures and sea ice cover is analyzed. The model reproduces the timing, structure, and interannual variability of the observed spring onset, thus providing a platform for addressing its dynamics. It is found that atmospheric eddy heat fluxes across the Arctic boundary, highly variable in winter but much less so in spring, shape the transition and determine its timing. Together with the rapid springtime increase of solar heating, the decreased variability in dynamical heating creates the abrupt appearance of the spring transition. Perpetual season simulations for winter, early spring, and late spring further reveal the dynamics of seasonally varying dynamical heating. The eddy heat flux is less variable in spring than winter because the variance of the eddy meridional wind and the stationary wave in temperature, resulting from land–sea contrast, both weaken. Further analysis shows that the strong wintertime variance in meridional wind is associated with traveling planetary wavenumber 1, which amplifies when its phase corresponds to an east–west dipole spanning the Greenland Sea. In this configuration the transient wind–stationary thermal interaction releases zonal available potential energy into wavenumber 1. Thus the highly variable wintertime dynamical heating of the Arctic arises from a baroclinic mechanism, but one distinct from baroclinic instability or cyclogenesis.

Assessing the Accuracy of a Linearized Observation Operator for Assimilation of Radio Occultation Data: Case Simulations with a High-Resolution Weather Model

2005 ◽  
Vol 133 (8) ◽  
pp. 2200-2212 ◽  
Author(s):  
Sergey Sokolovskiy ◽  
Ying-Hwa Kuo ◽  
Wei Wang
Keyword(s):  
High Resolution ◽  
Radio Occultation ◽  
Prediction Models ◽  
Weather Prediction ◽  
Atmospheric Model ◽  
Horizontal Resolution ◽  
Linear Modeling ◽  
Observation Operator ◽  
Phase Path ◽  
Excess Phase

Abstract Assimilation into numerical weather models of the refractivity, Abel-retrieved from radio occultations, as the local refractivity at ray tangent point may result in large errors in the presence of strong horizontal gradients (atmospheric fronts, strong convection). To reduce these errors, other authors suggested modeling the Abel-retrieved refractivity as a nonlocal linear function of the 3D refractivity, which can be used as a linear observation operator for assimiliation. The authors of this study introduce their approach for the nonlocal linear observation operator, which consists of modeling the excess phase path, calculated along certain trajectories below the top of an atmospheric model. In this study (not aimed at development of an observation operator for any specific atmospheric model), both approaches are validated by assessing the accuracy of both linearized observation operators by numerical simulations with the high-resolution Weather Research and Forecasting (WRF) model and comparing them to the accuracy of interpretation of the Abel-retrieved refractivity as local. Improvement of the accuracy of about an order of magnitude is found with the nonlocal refractivity and further improvement is found with the excess phase path. The effect of horizontal resolution of an atmospheric model on the accuracy of modeling local and nonlocal linear observables is also investigated, and it is demonstrated that the nonlocal linear modeling of radio occultation observables is especially important for weather prediction models with sufficiently high horizontal resolution, grid size <100 km (mesoscale models).

scholarly journals International Arctic Systems for Observing the Atmosphere: An International Polar Year Legacy Consortium

2016 ◽  
Vol 97 (6) ◽  
pp. 1033-1056 ◽  
Author(s):  
Taneil Uttal ◽  
Sandra Starkweather ◽  
James R. Drummond ◽  
Timo Vihma ◽  
Alexander P. Makshtas ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Satellite Observations ◽  
The Arctic ◽  
International Polar Year ◽  
Network Measurements ◽  
International Polar ◽  
In Situ Observations ◽  
Arctic Atmosphere

Abstract International Arctic Systems for Observing the Atmosphere (IASOA) activities and partnerships were initiated as a part of the 2007–09 International Polar Year (IPY) and are expected to continue for many decades as a legacy program. The IASOA focus is on coordinating intensive measurements of the Arctic atmosphere collected in the United States, Canada, Russia, Norway, Finland, and Greenland to create synthesis science that leads to an understanding of why and not just how the Arctic atmosphere is evolving. The IASOA premise is that there are limitations with Arctic modeling and satellite observations that can only be addressed with boots-on-the-ground, in situ observations and that the potential of combining individual station and network measurements into an integrated observing system is tremendous. The IASOA vision is that by further integrating with other network observing programs focusing on hydrology, glaciology, oceanography, terrestrial, and biological systems it will be possible to understand the mechanisms of the entire Arctic system, perhaps well enough for humans to mitigate undesirable variations and adapt to inevitable change.

scholarly journals Planetary and synoptic scale adjustment of the Arctic atmosphere to sea ice cover changes

2007 ◽  
Vol 34 (17) ◽  
Author(s):  
E. Sokolova ◽  
K. Dethloff ◽  
A. Rinke ◽  
A. Benkel
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
The Arctic ◽  
Synoptic Scale ◽  
Arctic Atmosphere

Vulnerability and Importance of Arctic Wetlands as large-scale nature-based solutions for Sustainability in a Changing Climate

2021 ◽  
Author(s):  
Elisie Kåresdotter ◽  
Zahra Kalantari
Keyword(s):  
Ecosystem Services ◽  
High Resolution ◽  
Large Scale ◽  
Natural Capital ◽  
Environmental Benefits ◽  
Indigenous Populations ◽  
The Arctic ◽  
Current Status ◽  
Human Beings ◽  
Arctic Wetlands

<p>Wetlands as large-scale nature-based solutions (NBS) provide multiple ecosystem services of local, regional, and global importance. Knowledge concerning location and vulnerability of wetlands, specifically in the Arctic, is vital to understand and assess the current status and future potential changes in the Arctic. Using available high-resolution wetland databases together with datasets on soil wetness and soil types, we created the first high-resolution map with full coverage of Arctic wetlands. Arctic wetlands' vulnerability is assessed for the years 2050, 2075, and 2100 by utilizing datasets of permafrost extent and projected mean annual average temperature from HadGEM2-ES climate model outputs for three change scenarios (RCP2.6, 4.5, and 8.5). With approximately 25% of Arctic landmass covered with wetlands and 99% being in permafrost areas, Arctic wetlands are highly vulnerable to changes in all scenarios, apart from RCP2.6 where wetlands remain largely stable. Climate change threatens Arctic wetlands and can impact wetland functions and services. These changes can adversely affect the multiple services this sort of NBS can provide in terms of great social, economic, and environmental benefits to human beings. Consequently, negative changes in Arctic wetland ecosystems can escalate land-use conflicts resulting from natural capital exploitation when new areas become more accessible for use. Limiting changes to Arctic wetlands can help maintain their ecosystem services and limit societal challenges arising from thawing permafrost wetlands, especially for indigenous populations dependent on their ecosystem services. This study highlights areas subject to changes and provides useful information to better plan for a sustainable and social-ecological resilient Arctic.</p><p>Keywords: Arctic wetlands, permafrost thaw, regime shift vulnerability, climate projection</p>

High resolution mapping of the Arctic Ocean deepest area: Molloy Hole

2021 ◽  
Author(s):  
Roberta Ivaldi ◽  
Maurizio Demarte ◽  
Massimiliano Nannini ◽  
Giuseppe Aquino ◽  
Cosimo Brancati ◽  
...  
Keyword(s):  
Sustainable Development ◽  
High Resolution ◽  
Arctic Ocean ◽  
The Arctic ◽  
Joint Research ◽  
Ocean Science ◽  
Global Geodynamics ◽  
The Arctic Ocean ◽  
Seabed Mapping ◽  
Resolution Mapping

<p>New hydro-oceanographic data were collected in the Arctic Ocean during HIGN NORTH20 marine geophysical campaign performed in July 2020, in a COVID-19 pandemic period. HIGH NORTH20 was developed as part of the IT-Navy HIGH NORTH program, a Pluriannual Joint Research Program in the Arctic devoted to contribute to oceans knowledge in order to ensure ocean science improving conditions for sustainable development of the Ocean in the aim of United Nations Decade of Ocean Science for Sustainable development and the GEBCO - SEABED 2030 project. In order to contribute in exploration and high-resolution seabed mapping new data was collected using a multibeam echosounder (EM 302 - 30 kHz). The particular sea ice environmental condition with open-sea allowed to survey and mapping the Molloy Hole, the deepest sector of the Arctic Ocean, a key area in the global geodynamics and oceanographic context. A 3D model of the Molloy Hole (804 km<sup>2</sup>) and the detection of the deepest seafloor (5567m - 79° 08.9’ N 002° 47.0’ E) was obtained with a 10x10m grid in compliance to the IHO standards.</p>

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