A Second Benchmarking Exercise on Estimating Extreme Environmental Conditions: Methodology & Baseline Results

2021 ◽  
Author(s):  
Ed Mackay ◽  
Andreas F. Haselsteiner ◽  
Ryan G. Coe ◽  
Lance Manuel
Keyword(s):  
Environmental Conditions ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Offshore Structures ◽  
Industrial Control ◽  
Natural Climate Variability ◽  
Depth Analysis ◽  
Emissions Scenarios ◽  
Natural Climate

Abstract Estimating extreme environmental conditions remains a key challenge in the design of offshore structures. This paper describes an exercise for benchmarking methods for extreme environmental conditions, which follows on from an initial benchmarking exercise introduced at OMAE 2019. In this second exercise, we address the problem of estimating extreme metocean conditions in a variable and changing climate. The study makes use of several very long datasets from a global climate model, including a 165-year historical run, a 700-year pre-industrial control run, which represents a quasi-steady state climate, and several runs under various future emissions scenarios. The availability of the long datasets allows for an in-depth analysis of the uncertainties in the estimated extreme conditions and an attribution of the relative importance of uncertainties resulting from modelling choices, natural climate variability, and potential future changes to the climate. This paper outlines the methodology for the second collaborative benchmarking exercise as well as presenting baseline results for the selected datasets.

scholarly journals Uncertainty of Hydrological Model Components in Climate Change Studies over Two Nordic Quebec Catchments

2018 ◽  
Vol 19 (1) ◽  
pp. 27-46 ◽  
Author(s):  
Magali Troin ◽  
Richard Arsenault ◽  
Jean-Luc Martel ◽  
François Brissette
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Hydrological Model ◽  
Climate Model ◽  
Global Climate Model ◽  
Substantial Contribution ◽  
Climate Change Signal ◽  
Natural Climate Variability ◽  
Degree Day ◽  
Natural Climate

Abstract Projected climate change effects on hydrology are investigated for the 2041–60 horizon under the A2 emission scenarios using a multimodel approach over two snowmelt-dominated catchments in Canada. An ensemble of 105 members was obtained by combining seven snow models (SMs), five potential evapotranspiration (PET) methods, and three hydrological model (HM) structures. The study was performed using high-resolution simulations from the Canadian Regional Climate Model (CRCM–15 km) driven by two members of the third-generation Canadian Coupled Global Climate Model (CGCM3). This study aims to compare various combinations of SM–PET–HM in terms of their ability to simulate streamflows under the current climate and to evaluate how they affect the assessment of the climate change–induced hydrological impacts at the catchment scale. The variability of streamflow response caused by the use of different SMs (degree-day versus degree-day/energy balance), PET methods (temperature-based versus radiation-based methods), and HM structures is evaluated, as well as the uncertainty due to the natural climate variability (CRCM intermember variability). The hydroclimatic simulations cover 1961–90 in the present period and 2041–60 in the future period. The ensemble spread of the climate change signal on streamflow is large and varies with catchments. Using the variance decomposition on three hydrologic indicators, the HM structure was found to make the most substantial contribution to uncertainty, followed by the choice of the PET methods or natural climate variability, depending on the hydrologic indicator and the catchment. Snow models played a minor, almost negligible role in the assessment of the climate change impacts on streamflow for the study catchments.

scholarly journals Pliocene Model Intercomparison Project Experiment 1: implementation strategy and mid-Pliocene global climatology using GENESIS v3.0 GCM

2012 ◽  
Vol 5 (1) ◽  
pp. 73-85 ◽  
Author(s):  
S. J. Koenig ◽  
R. M. DeConto ◽  
D. Pollard
Keyword(s):  
Boundary Conditions ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Modern World ◽  
Model Intercomparison ◽  
Industrial Control ◽  
Sea Ice Extent ◽  
Orbital Parameters ◽  
Intercomparison Project

Abstract. The mid-Pliocene Warm Period (3.29 to 2.97 Ma BP) has been identified as an analogue for the future, with the potential to help understand climate processes in a warmer than modern world. Sets of climate proxies, combined to provide boundary conditions for Global Climate Model (GCM) simulations of the mid-Pliocene, form the basis for the international, data-driven Pliocene Model Intercomparison Project (PlioMIP). Here, we outline the strategy for implementing pre-industrial (modern) and mid-Pliocene forcings and boundary conditions into the GENESIS version 3 GCM, as part of PlioMIP. We describe the prescription of greenhouse gas concentrations and orbital parameters and the implementation of geographic boundary conditions such as land-ice-sea distribution, topography, sea surface temperatures, sea ice extent, vegetation, soils, and ice sheets. We further describe model-specific details including spin-up and integration times. In addition, the global climatology of the mid-Pliocene as simulated by the GENESIS v3 GCM is analyzed and compared to the pre-industrial control simulation. The simulated climate of the mid-Pliocene warm interval is found to differ considerably from pre-industrial. We identify model sensitivity to imposed forcings, and internal feedbacks that collectively affect both local and far-field responses. Our analysis points out the need to assess both the direct impacts of external forcings and the combined effects of indirect, internal feedbacks. This paper provides the basis for assessing model biases within the PlioMIP framework, and will be useful for comparisons with other studies of mid-Pliocene climates.

scholarly journals Thermal niches of planktonic foraminifera are static throughout glacial–interglacial climate change

2021 ◽  
Vol 118 (18) ◽  
pp. e2017105118
Author(s):  
Gwen S. Antell ◽  
Isabel S. Fenton ◽  
Paul J. Valdes ◽  
Erin E. Saupe
Keyword(s):  
Climate Change ◽  
Environmental Conditions ◽  
Climate Model ◽  
Global Climate ◽  
Extinction Risk ◽  
Global Climate Model ◽  
Planktonic Foraminifera ◽  
Mean Annual Temperature ◽  
Suitable Habitat ◽  
Evolutionary Relatedness

Abiotic niche lability reduces extinction risk by allowing species to adapt to changing environmental conditions in situ. In contrast, species with static niches must keep pace with the velocity of climate change as they track suitable habitat. The rate and frequency of niche lability have been studied on human timescales (months to decades) and geological timescales (millions of years), but lability on intermediate timescales (millennia) remains largely uninvestigated. Here, we quantified abiotic niche lability at 8-ka resolution across the last 700 ka of glacial–interglacial climate fluctuations, using the exceptionally well-known fossil record of planktonic foraminifera coupled with Atmosphere–Ocean Global Climate Model reconstructions of paleoclimate. We tracked foraminiferal niches through time along the univariate axis of mean annual temperature, measured both at the sea surface and at species’ depth habitats. Species’ temperature preferences were uncoupled from the global temperature regime, undermining a hypothesis of local adaptation to changing environmental conditions. Furthermore, intraspecific niches were equally similar through time, regardless of climate change magnitude on short timescales (8 ka) and across contrasts of glacial and interglacial extremes. Evolutionary trait models fitted to time series of occupied temperature values supported widespread niche stasis above randomly wandering or directional change. Ecotype explained little variation in species-level differences in niche lability after accounting for evolutionary relatedness. Together, these results suggest that warming and ocean acidification over the next hundreds to thousands of years could redistribute and reduce populations of foraminifera and other calcifying plankton, which are primary components of marine food webs and biogeochemical cycles.

scholarly journals Pliocene Model Intercomparison Project: implementation strategy and mid-Pliocene Global climatology using GENESIS v3.0 GCM

2011 ◽  
Vol 4 (4) ◽  
pp. 2577-2603 ◽  
Author(s):  
S. J. Koenig ◽  
R. M. DeConto ◽  
D. Pollard
Keyword(s):  
Boundary Conditions ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Modern World ◽  
Model Intercomparison ◽  
Industrial Control ◽  
Sea Ice Extent ◽  
Orbital Parameters ◽  
Intercomparison Project

Abstract. The mid-Pliocene Warm Period (3.29 to 2.97 Ma BP) has been identified as an analogue for the future, with the potential to help understand climate processes in a warmer than modern world. Sets of climate proxies, combined to provide boundary conditions for Global Climate Model (GCM) simulations of the mid-Pliocene, form the basis for the international, data-driven Pliocene Model Intercomparison Project (PlioMIP). Here, we outline the strategy for implementing pre-industrial (modern) and mid-Pliocene forcings and boundary conditions into the GENESIS version 3 GCM, as part of PlioMIP. We describe the prescription of greenhouse gas concentrations and orbital parameters and the implementation of geographic boundary conditions such as land-ice-sea distribution, topography, sea surface temperatures, sea ice extent, vegetation, soils, and ice sheets. We further describe model-specific details including spin-up and integration times. In addition, the global climatology of the mid-Pliocene as simulated by the GENESIS v3 GCM is analyzed and compared to the pre-industrial control simulation. The simulated climate of the mid-Pliocene warm interval is found to differ considerably from pre-industrial. We identify model sensitivity to imposed forcings, and internal feedbacks that collectively affect both local and far-field responses. Our analysis points out the need to assess both the direct impacts of external forcings and the combined effects of indirect, internal feedbacks. This paper provides the basis for assessing model biases within the PlioMIP framework, and will be useful for comparisons with other studies of mid-Pliocene climates.

Towards Assessing NARCCAP Regional Climate Model Credibility for the North American Monsoon: Current Climate Simulations*

2013 ◽  
Vol 26 (22) ◽  
pp. 8802-8826 ◽  
Author(s):  
Melissa S. Bukovsky ◽  
David J. Gochis ◽  
Linda O. Mearns
Keyword(s):  
North American ◽  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Regional Climate ◽  
North American Monsoon ◽  
The North ◽  
Current Climate ◽  
Depth Analysis

Abstract The authors examine 17 dynamically downscaled simulations produced as part of the North American Regional Climate Change Assessment Program (NARCCAP) for their skill in reproducing the North American monsoon system. The focus is on precipitation and the drivers behind the precipitation biases seen in the simulations of the current climate. Thus, a process-based approach to the question of model fidelity is taken in order to help assess confidence in this suite of simulations. The results show that the regional climate models (RCMs) forced with a reanalysis product and atmosphere-only global climate model (AGCM) time-slice simulations perform reasonably well over the core Mexican and southwest United States regions. Some of the dynamically downscaled simulations do, however, have strong dry biases in Arizona that are related to their inability to develop credible monsoon flow structure over the Gulf of California. When forced with different atmosphere–ocean coupled global climate models (AOGCMs) for the current period, the skill of the RCMs subdivides largely by the skill of the forcing or “parent” AOGCM. How the inherited biases affect the RCM simulations is investigated. While it is clear that the AOGCMs have a large influence on the RCMs, the authors also demonstrate where the regional models add value to the simulations and discuss the differential credibility of the six RCMs (17 total simulations), two AGCM time slices, and four AOGCMs examined herein. It is found that in-depth analysis of parent GCM and RCM scenarios can identify a meaningful subset of models that can produce credible simulations of the North American monsoon precipitation.

High bit rate ACTS experiments for performing global science - Keck Telescope and global climate model

1996 ◽  
Author(s):  
Larry Bergman ◽  
J. Gary ◽  
Burt Edelson ◽  
Neil Helm ◽  
Judith Cohen ◽  
...  
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Bit Rate ◽  
Global Science ◽  
High Bit Rate

scholarly journals A comparison of ship and satellite measurements of cloud properties with global climate model simulations in the southeast Pacific stratus deck

2010 ◽  
Vol 10 (14) ◽  
pp. 6527-6536 ◽  
Author(s):  
M. A. Brunke ◽  
S. P. de Szoeke ◽  
P. Zuidema ◽  
X. Zeng
Keyword(s):  
Diurnal Cycle ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Cloud Fraction ◽  
Cloud Base ◽  
Liquid Water Path ◽  
Cloud Properties ◽  
Southeast Pacific ◽  
Cloud Thickness

Abstract. Here, liquid water path (LWP), cloud fraction, cloud top height, and cloud base height retrieved by a suite of A-train satellite instruments (the CPR aboard CloudSat, CALIOP aboard CALIPSO, and MODIS aboard Aqua) are compared to ship observations from research cruises made in 2001 and 2003–2007 into the stratus/stratocumulus deck over the southeast Pacific Ocean. It is found that CloudSat radar-only LWP is generally too high over this region and the CloudSat/CALIPSO cloud bases are too low. This results in a relationship (LWP~h9) between CloudSat LWP and CALIPSO cloud thickness (h) that is very different from the adiabatic relationship (LWP~h2) from in situ observations. Such biases can be reduced if LWPs suspected to be contaminated by precipitation are eliminated, as determined by the maximum radar reflectivity Zmax>−15 dBZ in the apparent lower half of the cloud, and if cloud bases are determined based upon the adiabatically-determined cloud thickness (h~LWP1/2). Furthermore, comparing results from a global model (CAM3.1) to ship observations reveals that, while the simulated LWP is quite reasonable, the model cloud is too thick and too low, allowing the model to have LWPs that are almost independent of h. This model can also obtain a reasonable diurnal cycle in LWP and cloud fraction at a location roughly in the centre of this region (20° S, 85° W) but has an opposite diurnal cycle to those observed aboard ship at a location closer to the coast (20° S, 75° W). The diurnal cycle at the latter location is slightly improved in the newest version of the model (CAM4). However, the simulated clouds remain too thick and too low, as cloud bases are usually at or near the surface.

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