scholarly journals AMALi – the Airborne Mobile Aerosol Lidar for Arctic research

2009 ◽  
Vol 9 (5) ◽  
pp. 18745-18792 ◽  
Author(s):  
I. S. Stachlewska ◽  
R. Neuber ◽  
A. Lampert ◽  
C. Ritter ◽  
G. Wehrle
Keyword(s):  
Present State ◽  
Aerosol Particles ◽  
Weather Conditions ◽  
The Arctic ◽  
Polar Regions ◽  
Marine Research ◽  
The Past ◽  
Cloud Properties ◽  
And Performance

Abstract. The Airborne Mobile Aerosol Lidar (AMALi) is an instrument developed at the Alfred Wegener Institute for Polar and Marine Research for a trouble-free operation under the challenging weather conditions at the Earth's polar regions. Since 2003 the AMALi has been successfully deployed for measurements in the ground-based installation and the zenith- or nadir-aiming airborne configurations during several scientific campaigns in the Arctic. The lidar provides profiles of the total backscatter at two wavelengths, from which aerosol and cloud properties are derived. It measures also the linear depolarization of the backscattered return, allowing for the discrimination of thermodynamic cloud phase and the identification of the presence of non-spherical aerosol particles. This paper presents the capability characteristics and performance of the past and present state of the AMALi system, as well as discusses the ground-based and airborne evaluation schemes applied to invert the data.

scholarly journals AMALi – the Airborne Mobile Aerosol Lidar for Arctic research

2010 ◽  
Vol 10 (6) ◽  
pp. 2947-2963 ◽  
Author(s):  
I. S. Stachlewska ◽  
R. Neuber ◽  
A. Lampert ◽  
C. Ritter ◽  
G. Wehrle
Keyword(s):  
Weather Conditions ◽  
The Arctic ◽  
Unknown Boundary ◽  
Polar Regions ◽  
Raman Lidar ◽  
Reliable Operation ◽  
Marine Research ◽  
Cloud Properties ◽  
Iterative Inversion ◽  
532 Nm

Abstract. The Airborne Mobile Aerosol Lidar (AMALi) is an instrument developed at the Alfred Wegener Institute for Polar and Marine Research for reliable operation under the challenging weather conditions at the Earth's polar regions. Since 2003 the AMALi has been successfully deployed for measurements in ground-based installation and zenith- or nadir-pointing airborne configurations during several scientific campaigns in the Arctic. The lidar provides backscatter profiles at two wavelengths (355/532 nm or 1064/532 nm) together with the linear depolarization at 532 nm, from which aerosol and cloud properties can be derived. This paper presents the characteristics and capabilities of the AMALi system and gives examples of its usage for airborne and ground-based operations in the Arctic. As this backscatter lidar normally does not operate in aerosol-free layers special evaluation schemes are discussed, the nadir-pointing iterative inversion for the case of an unknown boundary condition and the two-stream approach for the extinction profile calculation if a second lidar system probes the same air mass. Also an intercomparison of the AMALi system with an established ground-based Koldewey Aerosol Raman Lidar (KARL) is given.

scholarly journals A low power automated MAX-DOAS instrument for the Arctic and other remote unmanned locations

2010 ◽  
Vol 3 (2) ◽  
pp. 429-439 ◽  
Author(s):  
D. Carlson ◽  
D. Donohoue ◽  
U. Platt ◽  
W. R. Simpson
Keyword(s):  
Environmental Parameters ◽  
The Arctic ◽  
Integration Time ◽  
Polar Regions ◽  
Design Concepts ◽  
Trace Gas Emissions ◽  
New Instrument ◽  
And Performance ◽  
Data Acquisition Program ◽  
Response Biases

Abstract. Multiple Axis Differential Optical Absorption Spectrometer (MAX-DOAS) systems are inherently very simple instruments, which have been shown to provide extremely useful information about a wide variety of environmental parameters. In order to exploit the potential of the technique we have developed a new field-deployable, passive MAX-DOAS system that is automated and uses little power (<3 W). This new instrument utilizes a fully enclosed scan head that protects all moving parts and optics from harsh environments. Instrument diagnostics, such as tilt monitoring and frost accumulation detection and removal, are integrated into the main data acquisition program, which then acts to remedy problems that were discovered. This full automation and data quality checking make this instrument ideal for long-term deployment at remote, unmanned locations around the world, such as in polar regions or in the monitoring of trace gas emissions from volcanoes. This instrument was recently integrated into an ice-tethered autonomous buoy and tested in Elson Lagoon, near Barrow, Alaska to monitor halogen chemistry in the Arctic. During this investigation, differential slant column densities (dSCDs) of BrO up to 6×1014 molecules/cm2 were observed. Typical spectral fit residual RMS optical densities were less than 6×10−4 for solar zenith angles (SZA) <80° and a 6-min integration time. Here we describe the design concepts and performance of this new MAX-DOAS instrument through detailed analyses of spectral quality, power usage, possible instrument response biases, and typical instrument operations.

Northern Ocean Inventories of Radionuclide Contamination: GIS Efforts to Determine the Past and Present State of the Environment in and Adjacent to the Arctic

2000 ◽  
Vol 40 (10) ◽  
pp. 853-868 ◽  
Author(s):  
Kathleen Crane ◽  
Jennifer Galasso ◽  
Clare Brown ◽  
Georgy Cherkashov ◽  
Gennady Ivanov ◽  
...  
Keyword(s):  
Present State ◽  
The Arctic ◽  
The Past ◽  
Radionuclide Contamination ◽  
State Of The Environment

scholarly journals Plant extinction excels plant speciation in the Anthropocene

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jian-Guo Gao ◽  
Hui Liu ◽  
Ning Wang ◽  
Jing Yang ◽  
Xiao-Ling Zhang
Keyword(s):  
Plant Species ◽  
Plant Traits ◽  
Extinction Risk ◽  
Plant Evolution ◽  
The Arctic ◽  
Polar Regions ◽  
Crop Species ◽  
The Past ◽  
Plant Extinction ◽  
Warming World

Abstract Background In the past several millenniums, we have domesticated several crop species that are crucial for human civilization, which is a symbol of significant human influence on plant evolution. A pressing question to address is if plant diversity will increase or decrease in this warming world since contradictory pieces of evidence exit of accelerating plant speciation and plant extinction in the Anthropocene. Results Comparison may be made of the Anthropocene with the past geological times characterised by a warming climate, e.g., the Palaeocene-Eocene Thermal Maximum (PETM) 55.8 million years ago (Mya)—a period of “crocodiles in the Arctic”, during which plants saw accelerated speciation through autopolyploid speciation. Three accelerators of plant speciation were reasonably identified in the Anthropocene, including cities, polar regions and botanical gardens where new plant species might be accelerating formed through autopolyploid speciation and hybridization. Conclusions However, this kind of positive effect of climate warming on new plant species formation would be thoroughly offset by direct and indirect intensive human exploitation and human disturbances that cause habitat loss, deforestation, land use change, climate change, and pollution, thus leading to higher extinction risk than speciation in the Anthropocene. At last, four research directions are proposed to deepen our understanding of how plant traits affect speciation and extinction, why we need to make good use of polar regions to study the mechanisms of dispersion and invasion, how to maximize the conservation of plant genetics, species, and diverse landscapes and ecosystems and a holistic perspective on plant speciation and extinction is needed to integrate spatiotemporally.

scholarly journals Ground-based lidar measurements from Ny-Ålesund during ASTAR 2007

2009 ◽  
Vol 9 (22) ◽  
pp. 9059-9081 ◽  
Author(s):  
A. Hoffmann ◽  
C. Ritter ◽  
M. Stock ◽  
M. Shiobara ◽  
A. Lampert ◽  
...  
Keyword(s):  
Optical Properties ◽  
Weather Conditions ◽  
The Arctic ◽  
Particle Detection ◽  
Marine Research ◽  
Air Mass ◽  
Tropospheric Aerosol ◽  
Ground Based Lidar ◽  
Micro Pulse Lidar ◽  
Mixed Phase Clouds

Abstract. During the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) in March and April 2007, measurements obtained at the AWIPEV Arctic Research Base in Ny-Ålesund, Spitsbergen at 78.9° N, 11.9° E (operated by the Alfred Wegener Institute for Polar and Marine Research – AWI and the Institut polaire français Paul-Emile Victor – IPEV), supported the airborne campaign. This included lidar data from the Koldewey Aerosol Raman Lidar (KARL) and the Micro Pulse Lidar (MPL), located in the atmospheric observatory as well as photometer data and the daily launched radiosonde. The MPL features nearly continuous measurements; the KARL was switched on whenever weather conditions allowed observations (145 h in 61 days). From 1 March to 30 April, 71 meteorological balloon soundings were performed and compared with the concurrent MPL measurements; photometer measurements are available from 18 March. For the KARL data, a statistical overview of particle detection based on their optical properties backscatter ratio and volume depolarization can be given. The altitudes of the occurrence of the named features (subvisible and visible ice and water as well as mixed-phase clouds, aerosol layers) as well as their dependence on different air mass origins are analyzed. Although the spring 2007 was characterized by rather clean conditions, diverse case studies of cloud and aerosol occurrence during March and April 2007 are presented in more detail, including temporal development and main optical properties as depolarization, backscatter and extinction coefficients. Links between air mass origins and optical properties can be presumed but need further evidence.

Atmospheric hydrological cycles in the Arctic and Antarctic during the past four decades

2017 ◽  
Vol 7 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Kazuhiro Oshima ◽  
Koji Yamazaki
Keyword(s):  
Water Vapor ◽  
Moisture Transport ◽  
Moisture Flux ◽  
The Arctic ◽  
Polar Regions ◽  
Primary Input ◽  
The Past ◽  
Recent Climate ◽  
Hydrological Cycles ◽  
The Antarctic

Atmospheric hydrological cycles over the Arctic and Antarctic have been investigated in the previous studies and there are some similarity and dissimilarity in the two polar regions. The Arctic and Antarctic are areas of moisture flux convergence through the year. So the precipitation (P) exceeds the evaporation (E) and the net precipitation (P-E) is positive. Therefore, the atmospheric moisture transport is a primary input of water into the polar regions. Meanwhile the climatological seasonal cycles of P-E over these regions are dominated by transient moisture flux associated with cyclone activities, the interannual variations are governed by the stationary flux associated with the Arctic Oscillation and the Antarctic Oscillation (AAO). In addition, recent climate changes influence the polar hydrological cycles. Our analyses using an atmospheric reanalysis up to recent years indicated that there were no significant long-term changes in the poleward moisture transport into both the Arctic and Antarctic during 1979-2016. On the other hand, the water vapor (precipitable water) were clearly increasing over the Arctic and gradually decreasing over the Antarctic during the same period. As expected, the increasing trend of water vapor was due to the large warming over the Arctic. There were two reasons for the gradually decreasing trend of water vapor over the Antarctic. The first one was the positive trend of AAO in summer and the second was deepening trend of the Amundsen low in autumn. The trends in water vapor and temperature during the past 38 years further suggest that both polar regions were getting dryer in several seasons. The trend, however, needs to be confirmed by follow-up climatological analyses.

Error Structure and Atmospheric Temperature Trends in Observations from the Microwave Sounding Unit

2009 ◽  
Vol 22 (7) ◽  
pp. 1661-1681 ◽  
Author(s):  
Cheng-Zhi Zou ◽  
Mei Gao ◽  
Mitchell D. Goldberg
Keyword(s):  
Lower Stratosphere ◽  
Weather Conditions ◽  
Atmospheric Temperature ◽  
The Arctic ◽  
Polar Regions ◽  
Climate Trends ◽  
Orbital Geometry ◽  
Microwave Sounding Unit ◽  
Order Of Magnitude ◽  
Microwave Sounding

Abstract The Microwave Sounding Unit (MSU) onboard the National Oceanic and Atmospheric Administration polar-orbiting satellites measures the atmospheric temperature from the surface to the lower stratosphere under all weather conditions, excluding precipitation. Although designed primarily for monitoring weather processes, the MSU observations have been extensively used for detecting climate trends, and calibration errors are a major source of uncertainty. To reduce this uncertainty, an intercalibration method based on the simultaneous nadir overpass (SNO) matchups for the MSU instruments on satellites NOAA-10, -11, -12, and -14 was developed. Due to orbital geometry, the SNO matchups are confined to the polar regions, where the brightness temperature range is slightly smaller than the global range. Nevertheless, the resulting calibration coefficients are applied globally to the entire life cycle of an MSU satellite. Such intercalibration reduces intersatellite biases by an order of magnitude compared to prelaunch calibration and, thus, results in well-merged time series for the MSU channels 2, 3, and 4, which respectively represent the deep layer temperature of the midtroposphere (T2), tropopause (T3), and lower stratosphere (T4). Focusing on the global atmosphere over ocean surfaces, trends for the SNO-calibrated T2, T3, and T4 are, respectively, 0.21 ± 0.07, 0.08 ± 0.08, and −0.38 ± 0.27 K decade−1 from 1987 to 2006. These trends are independent of the number of limb-corrected footprints used in the dataset, and trend differences are marginal for varying bias correction techniques for merging the overlapping satellites on top of the SNO calibration. The spatial pattern of the trends reveals the tropical midtroposphere to have warmed at a rate of 0.28 ± 0.19 K decade−1, while the Arctic atmosphere warmed 2 to 3 times faster than the global average. The troposphere and lower stratosphere, however, cooled across the southern Indian and Atlantic Oceans adjacent to the Antarctic continent. To remove the stratospheric cooling effect in T2, channel trends from T2 and T3 (T23) and T2 and T4 (T24) were combined. The trend patterns for T23 and T24 are in close agreement, suggesting internal consistencies for the trend patterns of the three channels.

scholarly journals The polar regions in a 2°C warmer world

2019 ◽  
Vol 5 (12) ◽  
pp. eaaw9883 ◽  
Author(s):  
Eric Post ◽  
Richard B. Alley ◽  
Torben R. Christensen ◽  
Marc Macias-Fauria ◽  
Bruce C. Forbes ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
High Latitude ◽  
The Arctic ◽  
Polar Regions ◽  
Arctic Warming ◽  
The Past ◽  
Species Invasions ◽  
Northern High Latitude ◽  
Global Sea Level

Over the past decade, the Arctic has warmed by 0.75°C, far outpacing the global average, while Antarctic temperatures have remained comparatively stable. As Earth approaches 2°C warming, the Arctic and Antarctic may reach 4°C and 2°C mean annual warming, and 7°C and 3°C winter warming, respectively. Expected consequences of increased Arctic warming include ongoing loss of land and sea ice, threats to wildlife and traditional human livelihoods, increased methane emissions, and extreme weather at lower latitudes. With low biodiversity, Antarctic ecosystems may be vulnerable to state shifts and species invasions. Land ice loss in both regions will contribute substantially to global sea level rise, with up to 3 m rise possible if certain thresholds are crossed. Mitigation efforts can slow or reduce warming, but without them northern high latitude warming may accelerate in the next two to four decades. International cooperation will be crucial to foreseeing and adapting to expected changes.

scholarly journals Regional impacts of climate change in the Arctic and Antarctic

1998 ◽  
Vol 27 ◽  
pp. 543-552 ◽  
Author(s):  
Gunter Weller
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Climate Impacts ◽  
Indigenous Populations ◽  
The Arctic ◽  
Future Climate Change ◽  
Greenhouse Warming ◽  
Polar Regions ◽  
Sea Ice Extent ◽  
The Past

Regional assessments of impacts due to global climate change are a high priority in the international programs on global-change research. in the polar regions, climate models indicate an amplification of global greenhouse warming, but there are large differences between the results of various models, and uncertainties about the magnitude and timing of the expected changes. Also, the observed high-latitude climate trends over the past few decades are much more regional and patchy than predicted by the models. As a first step in assessing possible climate impacts, model results are compared with observations of changes in temperature, precipitation, sea-ice extent, the permafrost regime and other cryospheric parameters. While considerable uncertainties remain in the long-term prediction of change, there is some agreement between model results and observed trends by season on shorter time-scales, The warming observed over the land masses of the Arctic over the past few decades is matched by corresponding observed decreases in snow cover the glacier mass, balances, by thawing of the permafrost, and to a lesser degree by reductions in sea-ice extent. in Antarctica, warming in the Antarctic Peninsula and Ross Sea regions is associated with large decreases in ice-shelf areas and reduced ice thicknesses on the lakes in the McMurdo Dry Valleys. Major future impacts due to global greenhouse warming are likely to include permafrost thawing on and and its consequences for ecosystems and humans; changes in the productivity of marine ecosystems in the Arctic and Southern Ocean: economic impacts on fisheries, petroleum and other human activities; and social impacts on northern indigenous populations. Some of these impacts will have positive ramifications, but most are likely to be detrimental. While uncertainties exist about the future, climate change in the polar regions during the past few decades can be shown to have had major impacts already which will become much mole pronounced if present trends continue.

DYAMOND-II simulations with IFS-FESOM2

2021 ◽  
Author(s):  
Thomas Rackow ◽  
Nils Wedi ◽  
Kristian Mogensen ◽  
Peter Dueben ◽  
Helge F. Goessling ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ocean Circulation ◽  
Climate Model ◽  
Global Climate Model ◽  
The Arctic ◽  
Global Ocean ◽  
Polar Regions ◽  
Marine Research ◽  
Curvilinear Grid ◽  
The Impact

&lt;p&gt;This presentation will give an overview about an ongoing collaboration between the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). Our recent development is a single-executable coupled configuration of the Integrated Forecasting System (IFS) and the Finite Volume Sea Ice-Ocean Model, FESOM2. This configuration is set up to participate in the DYAMOND project alongside ECMWF&amp;#8217;s default IFS-NEMO configuration. IFS-FESOM2 and IFS-NEMO are tentative models to generate &amp;#8220;Digital Twin&amp;#8221; storm-scale, coupled simulations as envisioned in the European Destination Earth (DestinE) and Next Generation Earth Modelling Systems (NextGEMS) projects.&lt;/p&gt;&lt;p&gt;FESOM2 has a novel dynamical core that supports multi-resolution triangular grids. The model and its predecessor FESOM1 have been used in many studies over the last decade, with a focus on the role of the polar regions in global ocean circulation. The impact of eddy-permitting and locally eddy-resolving resolution has been addressed in CMIP6 and HighResMIP simulations as part of the AWI-CM-1-1 global climate model, while simulations with up to 1km resolution in the Arctic Ocean have been performed in stand-alone mode.&lt;/p&gt;&lt;p&gt;Initially, two coupled IFS-FESOM2 configurations have been tested: A coarse-resolution setup with a nominal 1&amp;#176; ocean, and a DYAMOND-II configuration with 0.25&amp;#176; ocean and IFS at 4.5km global resolution on average. For the latter configuration, FESOM2 is mimicking the &amp;#8220;ORCA025&amp;#8221; tri-polar curvilinear grid of the NEMO model, whose grid boxes have been split into triangles. Initialisation is from ECMWF&amp;#8217;s analysis for IFS and NEMO, and from an ERA5-forced ocean spin-up for FESOM2. We discuss technical challenges with respect to the hybrid OpenMP and MPI parallelization in a single-executable context, describe a novel strategy for resource-efficient writing of model output, and summarise future applications such as exploring the impact of flexible FESOM2 grid configurations on the atmosphere - with ocean simulations that resolve leads in sea ice and ocean eddies almost everywhere.&lt;/p&gt;

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