scholarly journals Compound Hydrometeorological Extremes: Drivers, Mechanisms and Methods

2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Zhang ◽  
Ming Luo ◽  
Si Gao ◽  
Weilin Chen ◽  
Vittal Hari ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Statistical Modeling ◽  
Storm Surge ◽  
Climate Models ◽  
Heat Waves ◽  
Numerical Models ◽  
Global Climate ◽  
The State ◽  
Global Climate Models

Compound extremes pose immense challenges and hazards to communities, and this is particularly true for compound hydrometeorological extremes associated with deadly floods, surges, droughts, and heat waves. To mitigate and better adapt to compound hydrometeorological extremes, we need to better understand the state of knowledge of such extremes. Here we review the current advances in understanding compound hydrometeorological extremes: compound heat wave and drought (hot-dry), compound heat stress and extreme precipitation (hot-wet), cold-wet, cold-dry and compound flooding. We focus on the drivers of these extremes and methods used to investigate and quantify their associated risk. Overall, hot-dry compound extremes are tied to subtropical highs, blocking highs, atmospheric stagnation events, and planetary wave patterns, which are modulated by atmosphere-land feedbacks. Compared with hot-dry compound extremes, hot-wet events are less examined in the literature with most works focusing on case studies. The cold-wet compound events are commonly associated with snowfall and cold frontal systems. Although cold-dry events have been found to decrease, their underlying mechanisms require further investigation. Compound flooding encompasses storm surge and high rainfall, storm surge and sea level rise, storm surge and riverine flooding, and coastal and riverine flooding. Overall, there is a growing risk of compound flooding in the future due to changes in sea level rise, storm intensity, storm precipitation, and land-use-land-cover change. To understand processes and interactions underlying compound extremes, numerical models have been used to complement statistical modeling of the dependence between the components of compound extremes. While global climate models can simulate certain types of compound extremes, high-resolution regional models coupled with land and hydrological models are required to simulate the variability of compound extremes and to project changes in the risk of such extremes. In terms of statistical modeling of compound extremes, previous studies have used empirical approach, event coincidence analysis, multivariate distribution, the indicator approach, quantile regression and the Markov Chain method to understand the dependence, greatly advancing the state of science of compound extremes. Overall, the selection of methods depends on the type of compound extremes of interests and relevant variables.

scholarly journals Modeling of Future Sea Level Rise Through Melting Glaciers

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Manoj Kumar Singh ◽  
Bharat Raj Singh
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
21St Century ◽  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
Sea Level Changes ◽  
Systematic Analysis ◽  
Ice Caps ◽  
Mountain Glaciers

The aim of this paper is to project 21st century volume changes of all mountain glacier and ice caps and to provide systematic analysis of uncertainties originating from different sources in the and their contribution to sea level rise and the assessment of uncertainties. Trends in global climate warming and sea level rise are observed during the last 100-years which both, according to global climate models, will continue in the future Intergovernmental Panel on Climate Change (IPCC) State-of-threat knowledge on climate, ocean and land processes identifies melting mountain glaciers and ice caps, after ocean thermal expansion, as the currently second major contributor to sea level rise. However, both the observations and models on sea level changes carry a variety of uncertainties. In this section, by following the question-answer concept, I will briefly present the importance of global sea level change for society, the current state of knowledge of sea level changes in response to climate change and the attempts to project future sea level changes until 2100 including discussion on related uncertainties. Melting mountain glaciers and ice caps (MG&IC) are the second largest contributor to rising sea level after thermal expansion of the oceans and are likely to remain the dominant glaciological contributor to rising sea level in the 21st century. The aim of this work is to project 21st century volume changes of all MG&IC and to provide systematic analysis of uncertainties originating from different sources in the calculation. I provide an ensemble of 21st century volume rojections for all MG&IC from the World Glacier Inventory by modeling the surface mass balance coupled with volume-area-length scaling and forced with temperature and precipitation scenarios from four Global Climate Models (GCMs). By upscaling the volume projections through a regionally differentiated approach to all MG&IC outside Greenland and Antarctica (514,380 km2) I stimated total volume loss for the time period 2001-2100 to range from 0.039 to 0.150 m sea level equivalent. While three GCMs agree that Alaskan glaciers are the main contributors to the projected sea level rise, one GCM projected the largest total volume loss mainly due to Arctic MG&IC.

scholarly journals Assessing storm surge hazard and impact of sea level rise in the Lesser Antilles case study of Martinique

2017 ◽  
Vol 17 (9) ◽  
pp. 1559-1571 ◽  
Author(s):  
Yann Krien ◽  
Bernard Dudon ◽  
Jean Roger ◽  
Gael Arnaud ◽  
Narcisse Zahibo
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Numerical Models ◽  
Lesser Antilles ◽  
Adaptation Measures ◽  
Worst Case ◽  
Mitigation And Adaptation ◽  
The Impact

Abstract. In the Lesser Antilles, coastal inundations from hurricane-induced storm surges pose a great threat to lives, properties and ecosystems. Assessing current and future storm surge hazards with sufficient spatial resolution is of primary interest to help coastal planners and decision makers develop mitigation and adaptation measures. Here, we use wave–current numerical models and statistical methods to investigate worst case scenarios and 100-year surge levels for the case study of Martinique under present climate or considering a potential sea level rise. Results confirm that the wave setup plays a major role in the Lesser Antilles, where the narrow island shelf impedes the piling-up of large amounts of wind-driven water on the shoreline during extreme events. The radiation stress gradients thus contribute significantly to the total surge – up to 100 % in some cases. The nonlinear interactions of sea level rise (SLR) with bathymetry and topography are generally found to be relatively small in Martinique but can reach several tens of centimeters in low-lying areas where the inundation extent is strongly enhanced compared to present conditions. These findings further emphasize the importance of waves for developing operational storm surge warning systems in the Lesser Antilles and encourage caution when using static methods to assess the impact of sea level rise on storm surge hazard.

scholarly journals Assessing storm surge hazard and impact of sea level rise in Lesser Antilles-Case study of Martinique

2017 ◽  
Author(s):  
Yann Krien ◽  
Bernard Dudon ◽  
Jean Roger ◽  
Gaël Arnaud ◽  
Narcisse Zahibo
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Numerical Models ◽  
Lesser Antilles ◽  
Adaptation Measures ◽  
Worst Case ◽  
Mitigation And Adaptation ◽  
The Impact

Abstract. In the Lesser Antilles, coastal inundations from hurricane-induced storm surges cause great threats to lives, properties, and ecosystems. Assessing current and future storm surge hazard with sufficient spatial resolution is of primary interest to help coastal planners and decision makers develop mitigation and adaptation measures. Here, we use wave-current numerical models and statistical methods to investigate worst case scenarios and 100-year surge levels for the case study of Martinique, under present climate or considering a potential sea-level rise. Results confirm that the wave setup plays a major role in Lesser Antilles, where the narrow island shelf impedes the piling-up of large amounts of wind-driven water on the shoreline during extreme events. The radiation stress gradients thus contribute significantly to the total surge, up to 100 % in some cases. The non-linear interactions of sea level rise with bathymetry and topography are generally found to be relatively small in Martinique, but can reach several tens of centimeters in low-lying areas where the inundation extent is strongly enhanced compared to present conditions. These findings further emphasize the importance of waves for developing operational storm surge warning systems in the Lesser Antilles, and encourage caution when using static methods to assess the impact of sea level rise on storm surge hazard.

Major increases projected in extreme surface melt events in Antarctica, even under a moderate emission scenario

2020 ◽  
Author(s):  
Sarah Feron ◽  
Raul Cordero
Keyword(s):  
Sea Level ◽  
Antarctic Peninsula ◽  
Climate Models ◽  
Emission Scenario ◽  
Global Climate ◽  
Global Climate Models ◽  
Reference Period ◽  
West Antarctica ◽  
Surface Melt ◽  
The Antarctic

<p>Surface Melt (SM) is one of the factors that contribute to sea level rise; surface meltwater draining through the ice and beneath Antarctic glaciers may cause acceleration in their flow towards the sea. Changes in the frequency of relatively warm days (including heatwaves) can substantially alter the SM variability, thus leading to extreme melting events. By using simulations from 13 Global Climate Models (GCMs) and according to a moderate representative concentration pathways (RCP4.5), here we show that the frequency of extreme SM events (SM90; according to the 90th percentile over the reference period 1961-1990) may significantly increase in coastal areas of West Antarctica; in particular in the Antarctic Peninsula. By the end of the century SM90 estimates are expected to increase from currently 0.10 kg/m2/day to about 0.45 kg/m2/day in the Antarctic Peninsula. Increments in SM90 estimates are not just driven by changes in the average SM, but also by the variability in SM. The latter is expected to increase by around 50% in the Antarctic Peninsula.</p>

scholarly journals Application of prognostic ensembles of global climate models to generate distributed estimates of water content in catchment basins

2021 ◽  
Vol 289 ◽  
pp. 01009
Author(s):  
Valeriya Petruhina
Keyword(s):  
Climate Change ◽  
Twentieth Century ◽  
Water Content ◽  
Human Impact ◽  
Climate Models ◽  
Global Climate ◽  
The State ◽  
Global Climate Models ◽  
Spatially Distributed ◽  
Long Time

The problem of predicting climate change and its impact on humans is quite important and relevant in recent times. For a long time, mechanisms and methods for predicting the behavior of the climate in various regions and regions of our planet have been developed. Due to climate change, aggressive human impact on nature, and other various factors, the methods developed in the mid-twentieth century are becoming ineffective, and it is time-consuming but feasible to calculate using several methods. The article considers the technology of processing geoclimatic data, which is used to form spatially distributed predictive estimates of the state of the atmosphere.

scholarly journals Air Temperature and Precipitation at Wolverine Glacier, Alaska; Glacier Growth in a Warmer, Wetter Climate

1990 ◽  
Vol 14 ◽  
pp. 191-194 ◽  
Author(s):  
L.R. Mayo ◽  
R.S. March
Keyword(s):  
Sea Level ◽  
Air Temperature ◽  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
Positive Mass ◽  
Temperature And Precipitation ◽  
Warming Climate ◽  
The Common ◽  
Snow Precipitation

Measurements at Wolverine Glacier, Alaska, from 1968 to 1988 indicate unsteady increases of air temperature and precipitation since the early 1970s. These increases were due almost entirely to changes in winter. Variations in annual temperature and precipitation at Wolverine Glacier and at Seward, a nearby climatological station at sea level, correlate positively with global temperature variations and are in general agreement with the changes at high latitudes predicted by five recent general atmospheric circulation models forced by anticipated rises of CO2. A consequence of the air temperature and precipitation increases at Wolverine Glacier was a change to a generally positive mass balance after 1976. Although these observations in the coastal maritime climate of Alaska run against the common, oversimplified notion that in a warming climate glaciers will melt, causing sea level to rise, they are logical and easily understood when the sensitivity of the glacier to the seasonal distribution of the changes is considered. The observed seasonal changes at Wolverine Glacier also are in agreement with global climate models. Snow precipitation and glacier accumulation increased, but at the same time warming affected only these those temperatures below about −5°C, and melting was not altered. The extent of this response is not well known, but the process may be taking place in other important glacierized regions.

ISMIP6-based projections of ocean-forced Antarctic ice loss using the Community Ice Sheet Model 

2021 ◽  
Author(s):  
William Lipscomb ◽  
Gunter Leguy ◽  
Nicolas Jourdain ◽  
Xylar Asay-Davis ◽  
Hélène Seroussi ◽  
...  
Keyword(s):  
Sea Level ◽  
Climate Models ◽  
Global Climate ◽  
Ice Sheet ◽  
High Sensitivity ◽  
Global Climate Models ◽  
Thermal Forcing ◽  
Antarctic Ice Sheet ◽  
Basal Friction ◽  
West Antarctic

<p>The future retreat rate for marine-based regions of the Antarctic Ice Sheet is one of the largest uncertainties in sea-level projections. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) aims to improve projections and quantify uncertainties by running an ensemble of ice sheet models with forcing derived from global climate models. Here, the Community Ice Sheet Model (CISM) is used to run ISMIP6-based projections of ocean-forced Antarctic Ice Sheet evolution. Using several combinations of sub-ice-shelf melt schemes, CISM is spun up to steady state over many millennia. During the spin-up, basal-friction and thermal-forcing parameters are adjusted to optimize agreement with the observed ice thickness. The model is then run forward to year 2500, applying ocean thermal forcing anomalies from six climate models. In all simulations, ocean warming triggers long-term retreat of the West Antarctic Ice Sheet, especially in the Filchner-Ronne and Ross sectors. The ocean-forced sea-level rise in 2500 varies from about 150 mm to 1300 mm, depending on the melt scheme and ocean forcing applied. Further experiments show relatively high sensitivity to the basal friction law, and moderate sensitivity to grid resolution and the prescribed collapse of small ice shelves. The Amundsen sector exhibits threshold behavior, with modest retreat under many parameter settings, but complete collapse under some combinations of low basal friction and high thermal-forcing anomalies. Large uncertainties remain, as a result of parameterized sub-shelf melt rates, simplified treatments of calving and basal friction, and the lack of ice–ocean coupling.</p>

A regional atmospheric warming threshold for irreversible Greenland ice sheet mass loss

2020 ◽  
Author(s):  
Michiel van den Broeke ◽  
Brice Noël ◽  
Leo van Kampenhout ◽  
Willem-Jan van de Berg
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Sea Level Rise ◽  
Sea Level ◽  
Climate Models ◽  
Climate Model ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Global Climate Models ◽  
The Future

<p>The mass balance of the Greenland ice sheet (GrIS, units Gt per year) equals the surface mass balance (SMB) minus solid ice discharge across the grounding line. As the latter is definite positive, an important threshold for irreversible GrIS mass loss occurs when long-term average SMB becomes negative. For this to happen, runoff (mainly meltwater, some rain) must exceed mass accumulation (mainly snowfall minus sublimation). Even for a single year, this threshold has not been passed since at least 1958, the first year with reliable estimates of SMB components, although recent years with warm summers (e.g. 2012 and 2019) came close. Simply extrapolating the recent (1991-present) negative SMB trend into the future suggests that the SMB = 0 threshold could be reached before ~2040, but such predictions are extremely uncertain given the very large interannual SMB variability, the relative brevity of the time series and the uncertainty in future warming. In this study we use a cascade of models, extensively evaluated with in-situ and remotely sensed (GRACE) SMB observations, to better constrain the future regional warming threshold for the 5-year average GrIS SMB to become negative. To this end, a 1950-2100 climate change run with the global model CESM2 (app. 100 km resolution) was dynamically downscaled using the regional climate model RACMO2 (app. 11 km), which in turn was statistically downscaled to 1 km resolution. The result is a threshold regional Greenland warming of close to 4 degrees. We then use a range of CMIP5 and CMIP6 global climate models to translate the regional value into a global warming threshold for various warming scenarios, including its timing this century. We find substantial differences, ranging from stabilization before the threshold is reached in the RCP/SSP2.6 scenarios with a limited but still significant sea-level rise contribution (< 5 cm by 2100) to an imminent crossing of the warming threshold for the RCP/SSP8.5 scenarios with substantial and ever-growing contributions to sea level rise (> 10 cm by 2100). These results stress the need for strong mitigation to avoid irreversible GrIS mass loss. We finish by discussing the caveats and uncertainties of our approach.</p>

Air Temperature and Precipitation at Wolverine Glacier, Alaska; Glacier Growth in a Warmer, Wetter Climate

1990 ◽  
Vol 14 ◽  
pp. 191-194 ◽  
Author(s):  
L.R. Mayo ◽  
R.S. March
Keyword(s):  
Sea Level ◽  
Air Temperature ◽  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
Positive Mass ◽  
Temperature And Precipitation ◽  
Warming Climate ◽  
The Common ◽  
Snow Precipitation

Measurements at Wolverine Glacier, Alaska, from 1968 to 1988 indicate unsteady increases of air temperature and precipitation since the early 1970s. These increases were due almost entirely to changes in winter. Variations in annual temperature and precipitation at Wolverine Glacier and at Seward, a nearby climatological station at sea level, correlate positively with global temperature variations and are in general agreement with the changes at high latitudes predicted by five recent general atmospheric circulation models forced by anticipated rises of CO2.A consequence of the air temperature and precipitation increases at Wolverine Glacier was a change to a generally positive mass balance after 1976. Although these observations in the coastal maritime climate of Alaska run against the common, oversimplified notion that in a warming climate glaciers will melt, causing sea level to rise, they are logical and easily understood when the sensitivity of the glacier to the seasonal distribution of the changes is considered. The observed seasonal changes at Wolverine Glacier also are in agreement with global climate models. Snow precipitation and glacier accumulation increased, but at the same time warming affected only these those temperatures below about −5°C, and melting was not altered. The extent of this response is not well known, but the process may be taking place in other important glacierized regions.

Uncertainties of creek evolution in coastal wetlands facing sea-level rise

2020 ◽  
Author(s):  
Xiaorong Li ◽  
Nicoletta Leonardi ◽  
Andy Plater
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Wetlands ◽  
Numerical Models ◽  
Global Climate ◽  
Environmental Stressors ◽  
Loss Of Life ◽  
Global Challenge

<p>Adaptation of coastal areas facing climate change is a global challenge. Some of these low‐lying regions are commonly managed and engineered to reduce damage, loss of life, and environmental degradation caused by natural hazards originating from the sea. However, sea-level rise and changes in storm regimes are putting unprecedented pressure on these managed systems, forcing the adoption of “no active intervention” or “managed realignment” strategies in areas where “hold the line” options cannot be justified due to financial constraints. The aim of this research is to explore how disintegration of sea defences would affect creek topology under present day and future sea level rise scenarios, using the Hesketh marsh as a case study.  A reduced complexity numerical model is applied to produce ensemble predictions for analysis. Without the presence of vegetation, results suggest that creek geometry efficiency and density of tidal creeks are insensitive to sea level rise.</p><p>The model assumes the erodibility of the wetland is homogeneous and constant which leaves room for improvement because coastal environment is subject to changes as a result of global climate change and human activities. Changes in environmental stressors, such as sea level rise, elevated CO<sub>2</sub> concentration, changing storm patterns, etc. could adjust the resistance of the wetland to erosion in either way. Hence, the adequacy of current parameterizations of soil erodibility in numerical models requires further investigation.</p>

Sign in / Sign up

Export Citation Format

Share Document