scholarly journals Estimating Transient Climate Response in a Large‐Ensemble Global Climate Model Simulation

2019 ◽  
Vol 46 (1) ◽  
pp. 311-317 ◽  
Author(s):  
B. K. Adams ◽  
A. E. Dessler
Keyword(s):  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Global Climate Model ◽  
Climate Response ◽  
Large Ensemble ◽  
Transient Climate Response ◽  
Climate Model Simulation ◽  
Global Climate Model Simulation

Impact of δ-Four-Stream Radiative Transfer Scheme on global climate model simulation

2020 ◽  
Vol 243 ◽  
pp. 106800
Author(s):  
Quan Yang ◽  
Feng Zhang ◽  
Hua Zhang ◽  
Zhili Wang ◽  
Hironobu Iwabuchi ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Global Climate Model ◽  
Transfer Scheme ◽  
Climate Model Simulation ◽  
Global Climate Model Simulation

scholarly journals APPLICABILITY OF D4PDF DATASET TO GLOBAL STOCHASTIC TROPICAL CYCLONE MODEL

2020 ◽  
pp. 26
Author(s):  
Sota Nakajo ◽  
Jinji Umeda ◽  
Nobuhito Mori
Keyword(s):  
Tropical Cyclone ◽  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Global Climate Model ◽  
Observation Data ◽  
Change Rate ◽  
Regional Area ◽  
Global Climate Model Simulation ◽  
Disaster Event

Disaster damage caused by tropical cyclone has grown every year. However, our experience of tropical cyclone is not enough to evaluate very low frequent and catastrophic disaster event. Stochastic tropical cyclone model has been used for assessment of tropical cyclone disaster. Global stochastic model was improved by using a lot of ensemble Global Climate Model simulation data (d4PDF) instead of limited number of observation data. The model bias included d4PDF was corrected by each regional grid by simple statistical method and interpolation. The accuracy of new model was verified at representative regional area in different basins. Generally, the improvement is remarkable where tropical cyclones rarely passed. The variation of joint PDF of tropical cyclone change rate between previous model and present model agree with model improvement. As an example of application, the frequencies of strong tropical cyclone events of two cases were estimated.

scholarly journals Response of Summer Precipitation over Eastern China to Large Volcanic Eruptions

2010 ◽  
Vol 23 (3) ◽  
pp. 818-824 ◽  
Author(s):  
Youbing Peng ◽  
Caiming Shen ◽  
Wei-Chyung Wang ◽  
Ying Xu
Keyword(s):  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Global Climate Model ◽  
Regional Climate ◽  
Eastern China ◽  
Summer Precipitation ◽  
Volcanic Eruptions ◽  
Global Climate Model Simulation ◽  
Large Volcanic Eruptions

Abstract Studies of the effects of large volcanic eruptions on regional climate so far have focused mostly on temperature responses. Previous studies using proxy data suggested that coherent droughts over eastern China are associated with explosive low-latitude volcanic eruptions. Here, the authors present an investigation of the responses of summer precipitation over eastern China to large volcanic eruptions through analyzing a 1000-yr global climate model simulation driven by natural and anthropogenic forcing. Superposed epoch analyses of 18 cases of large volcanic eruption indicate that summer precipitation over eastern China significantly decreases in the eruption year and the year after. Model simulation suggests that this reduction of summer precipitation over eastern China can be attributed to a weakening of summer monsoon and a decrease of moisture vapor over tropical oceans caused by large volcanic eruptions.

scholarly journals The Norwegian Earth System Model, NorESM1-M – Part 2: Climate response and scenario projections

2012 ◽  
Vol 5 (3) ◽  
pp. 2933-2998 ◽  
Author(s):  
T. Iversen ◽  
M. Bentsen ◽  
I. Bethke ◽  
J. B. Debernard ◽  
A. Kirkevåg ◽  
...  
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Ocean Model ◽  
Climate Response ◽  
Rcp Scenarios ◽  
Transient Climate Response ◽  
Near Surface ◽  
Enso Events ◽  
Model Average

Abstract. The NorESM1-M simulation results for CMIP5 (http://cmip-pcmdi.llnl.gov/cmip5/index.html) are described and discussed. Together with the accompanying paper by Bentsen et al. (2012), this paper documents that NorESM1-M is a valuable global climate model for research and for providing complementary results to the evaluation of possible man made climate change. NorESM is based on the model CCSM4 operated at NCAR on behalf of many contributors in USA. The ocean model is replaced by a developed version of MICOM and the atmospheric model is extended with on-line calculations of aerosols, their direct effect, and their indirect effect on warm clouds. Model validation is presented in a companion paper (Bentsen et al., 2012). NorESM1-M is estimated to have equilibrium climate sensitivity slightly smaller than 2.9 K, a transient climate response just below 1.4 K, and is less sensitive than most other models. Cloud feedbacks damp the response, and a strong AMOC reduces the heat fraction available for increasing near surface temperatures, for evaporation, and for melting ice. The future projections based on RCP scenarios yield global surface air temperature increase almost one standard deviation lower than a 15-model average. Summer sea-ice is projected to decrease considerably by 2100, and completely for RCP8.5. The AMOC is projected to reduce by 12%, 15–17%, and 32% for the RCP2.6, 4.5, 6.0 and 8.5 respectively. Precipitation is projected to increase in the tropics, decrease in the subtropics and in southern parts of the northern extra-tropics during summer, and otherwise increase in most of the extra-tropics. Changes in the atmospheric water cycle indicate that precipitation events over continents will become more intense and dry spells more frequent. Extra-tropical storminess in the Northern Hemisphere is projected to shift northwards. There are indications of more frequent spring and summer blocking in the Euro-Atlantic sectors and that ENSO events weaken but appear more frequent. These indications are uncertain because of biases in the model's representation of present-day conditions. There are indications that positive phase PNA and negative phase NAO become less frequent under the RCP8.5 scenario, but also this result is considered uncertain. Single-forcing experiments indicate that aerosols and greenhouse gases produce similar geographical patterns of response for near surface temperature and precipitation. These patterns tend to have opposite sign, with important exceptions for precipitation at low latitudes. The asymmetric aerosol effects between the two hemispheres leads to a southward displacement of ITCZ. Both forcing agents thus tend to reduce northern hemispheric subtropical precipitation.

scholarly journals Internal Variability of the Canadian RCM’s Hydrological Variables at the Basin Scale in Quebec and Labrador

2012 ◽  
Vol 13 (2) ◽  
pp. 443-462 ◽  
Author(s):  
Marco Braun ◽  
Daniel Caya ◽  
Anne Frigon ◽  
Michel Slivitzky
Keyword(s):  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Global Climate Model ◽  
Regional Climate ◽  
Internal Variability ◽  
Spectral Nudging ◽  
Model Driven ◽  
Basin Scale ◽  
Hydrological Variables

Abstract The effect of a regional climate model’s (RCM’s) internal variability (IV) on climate statistics of annual series of hydrological variables is investigated at the scale of 21 eastern Canada watersheds in Quebec and Labrador. The analysis is carried out on 30-yr pairs of simulations (twins), performed with the Canadian Regional Climate Model (CRCM) for present (reanalysis and global climate model driven) and future (global climate model driven) climates. The twins differ only by the starting date of the regional simulation—a standard procedure used to trigger internal variability in RCMs. Two different domain sizes are considered: one comparable to domains used for RCM simulations over Europe and the other comparable to domains used for North America. Results for the larger North American domain indicate that mean relative differences between twin pairs of 30-yr climates reach ±5% when spectral nudging is used. Larger differences are found for extreme annual events, reaching about ±10% for 10% and 90% quantiles (Q10 and Q90). IV is smaller by about one order of magnitude in the smaller domain. Internal variability is unaffected by the period (past versus future climate) and by the type of driving data (reanalysis versus global climate model simulation) but shows a dependence on watershed size. When spectral nudging is deactivated in the large domain, the relative difference between pairs of 30-yr climate means almost doubles and approaches the magnitude of a global climate model’s internal variability. This IV at the level of the natural climate variability has a profound impact on the interpretation, analysis, and validation of RCM simulations over large domains.

scholarly journals Interhemispheric effect of global geography on Earth's climate response to orbital forcing

2019 ◽  
Vol 15 (1) ◽  
pp. 377-388
Author(s):  
Rajarshi Roychowdhury ◽  
Robert DeConto
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Climate Response ◽  
Orbital Forcing ◽  
Climate Data ◽  
Unequal Distribution ◽  
Summer Temperatures ◽  
Earth’S Climate ◽  
Climate Responses

Abstract. The climate response of the Earth to orbital forcing shows a distinct hemispheric asymmetry due to the unequal distribution of land in the Northern Hemisphere versus Southern Hemisphere. This asymmetry is examined using a global climate model (GCM) for different climate responses such as mean summer temperatures and positive degree days. A land asymmetry effect (LAE) is quantified for each hemisphere and the results show how changes in obliquity and precession translate into variations in the calculated LAE. We find that the global climate response to specific past orbits is likely unique and modified by complex climate–ocean–cryosphere interactions that remain poorly known. Nonetheless, these results provide a baseline for interpreting contemporaneous proxy climate data spanning a broad range of latitudes, which may be useful in paleoclimate data–model comparisons, and individual time-continuous records exhibiting orbital cyclicity.

scholarly journals Interhemispheric bias in earth's climate response to orbital forcing

2016 ◽  
Author(s):  
R. Roychowdhury ◽  
R. M. DeConto
Keyword(s):  
Data Model ◽  
Hemispheric Asymmetry ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Climate Response ◽  
Orbital Forcing ◽  
Climate Data ◽  
Unequal Distribution ◽  
Earth’S Climate

Abstract. The climate response to orbital forcing shows a distinct hemispheric asymmetry due to the unequal distribution of land in the Northern vs. Southern hemispheres. This asymmetry is examined using a Global Climate Model (GCM) and a Land Hemispheric Bias (LHB) is quantified for each hemisphere. The results show how changes in obliquity and precession translate into variations in the calculated LHB. We find that the global climate response to specific past orbits is likely unique and modified by complex climate-ocean-cryosphere interactions that remain poorly known and difficult to model. Nonetheless, these results provide a baseline for interpreting contemporaneous proxy climate data spanning a broad range of latitudes, which maybe especially useful in paleoclimate data-model comparisons, and individual time-continuous records exhibiting orbital cyclicity.

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