http://oldspiderwort.gfdl.noaa.gov/index/news-app Research highlights from oldspiderwort.gfdl.noaa.gov en 2013-06-19T13:45:27-04:00 hourly 1 1970-01-01T00:00+00:00 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.81/title.response-to-co2-doubling-of-the-atlantic-hurricane-main-development-region-in-a-high-resolution-climate-model The authors simulated the response of sea surface temperature (SST) in the Atlantic Hurricane Main Development Region (MDR) to a doubling of CO2, using a cutting-edge global high-resolution coupled model developed at GFDL (CM2.5). The model has been shown to produce a very faithful simulation of the observed seasonal cycle and year-to-year (or interannual) variability in the tropical Atlantic. The skillful representation of Atlantic interannual variability enables the exploration of the response of interannual variability to increasing CO2 – in addition to exploring changes in the average conditions in the Atlantic. Climate Change Variability and Prediction 2013-04-15 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.83/title.sensitivity-of-tropospheric-oxidants-to-biomass-burning-emissions-implications-for-radiative-forcing Biomass burning is one of the largest sources of trace gases and aerosols in the atmosphere, and has profound influence on tropospheric oxidants and radiative forcing. Using a fully coupled chemistry-climate model (GFDL AM3), the authors found that co-emission of trace gases and aerosol from present-day biomass burning increases the global tropospheric ozone burden by 5.1%, and decreases global mean OH, a major sink for methane, by 6.3%. Atmospheric Physics Chemistry and Climate 2013-03-29 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.80/title.ocean-warming-effect-on-surface-gravity-wave-climate-change-for-the-end-of-the-21st-century Future changes in wind-wave patterns have broad implications for ecosystems, as well as the design and operation of coastal, near-and-off-shore industries. Changes in response to global warming may further exacerbate the anticipated vulnerabilities of coastal regions to projected sea-level rise. Weather and Atmospheric Dynamics 2013-03-11 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.78/title.cloud-tuning-in-a-coupled-climate-model-impact-on-20th-century-warming Clouds remain one of the largest sources of uncertainty in predictions from climate models. Globally, clouds cool the Earth through the net effect of two opposing contributions: cooling from reflection of incoming solar radiation and warming from trapping of infrared radiation emitted by the Earth. By comparison, the cooling effect of clouds is estimated to be about six times larger than the warming effect resulting from the increase in anthropogenic greenhouse gases since 1750. This is why uncertainties in the representation of clouds can have considerable impact on the simulated climate. Atmospheric Physics Chemistry and Climate 2013-03-04 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.77/title.heat-stress-reduces-labor-capacity-under-climate-warming The authors use existing occupational health and safety thresholds to establish a new metric to quantify a healthy, acclimated individual’s capacity to safely perform sustained labor under environmental heat stress (what we call labor capacity). Using climate model projections, we apply this metric to quantify the direct impact of global warming on the global human population in the future. Climate and Ecosystems 2013-02-24 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.79/title.controls-of-global-snow-under-climate-change Understanding snowfall variability is key to understanding future water supply in snowmelt-dominated regions, like the western U.S. This research validated GFDL’s coupled climate models, CM2.5 and CM2.1, for snowfall and explored changes in snowfall in a future climate experiment, to determine if resolution differences in the models influence snowfall signals. Climate Change Variability and Prediction 2013-02-15 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.76/title.contributions-of-downstream-eddy-development-to-the-teleconnection-between-enso-and-the-atmospheric-circulation-over-the-north-atlantic El Nino-Southern Oscillation (ENSO) is the dominant pattern of interannual climate variability, and has strong influence on the atmospheric circulation around the globe. North Atlantic Oscillation (NAO) is another prominent mode of interannual variability in the Northern Hemisphere extratropics, and exerts a strong influence on the climate of the North Atlantic basin and the surrounding land areas. The main purpose of this study is to describe and assess of the interactions between these two prominent teleconnection patterns of the interannual climate variability. Climate Diagnostics 2013-02-01 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.74/title.springtime-high-surface-ozone-events-over-the-western-united-states-quantifying-the-role-of-stratospheric-intrusions Stratosphere-to-troposphere transport of ozone is a common occurrence at mid- and high latitudes, but its influence on tropospheric ozone levels remains a long-standing question, despite decades of research. GFDL scientists and colleagues analyzed balloon soundings, lidar, surface and satellite measurements using GFDL’s new global high-resolution chemistry-climate model, to look at the extent to which naturally occurring stratospheric ozone intrusions reach the surface and affect air quality. Atmospheric Physics Chemistry and Climate 2013-01-21 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.73/title.have-aerosols-caused-the-observed-atlantic-multi-decadal-variability- Identifying the main drivers of the twentieth-century multi-decadal variability in the Atlantic Ocean is crucial for predicting how the Atlantic will evolve in the coming decades and the resulting broad impacts on weather and precipitation patterns around the globe. Another recently published paper suggested that aerosols are a prime driver of twentieth-century North Atlantic climate variability, based on simulations using the HadGEM2-ES (UK Met Office Hadley Centre Earth System Model). Climate Change Variability and Prediction 2013-01-14 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.75/title.cusk-brosme-brosme-and-climate-change-assessing-the-threat-to-a-candidate-marine-fish-species-under-the-u-s-endangered-species-act This collaboration, led by NOAA and EPA scientists and entraining expertise from the University of Connecticut, evaluated the potential effects of climate change on cusk (Brosme brosme) in the Northwest Atlantic. Numbers of this demersal (bottom-dwelling) fish (Fig. 1) on the Northeast Atlantic continental shelf have declined dramatically over the past several decades. This is believed to be primarily a result of fishing activities. However, changes in the distribution and abundance of a number of marine fish stocks in the Northwest Atlantic have been linked to climate variability and change, suggesting that both fishing and climate may affect the future status of cusk. Climate and Ecosystems 2013-01-08 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.72/title.connecting-changing-ocean-circulation-with-changing-climate Our capability to observe ocean changes has improved dramatically over the past two decades, motivating interest in how these observations can be used to constrain climate change simulations. Projections of future surface climate change and ocean circulation change are both very uncertain. This research shows that circulation changes are important to the surface climate change and we describe a mechanism for the connection. Climate Change Variability and Prediction 2012-11-28 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.66/title.mixing-of-dust-and-nh3-observed-globally-over-anthropogenic-dust-sources Dust is one of the most abundant aerosols in the atmosphere, and by scattering and absorbing solar radiation, it affects climate. Anthropogenic dust is largely ignored in most current climate studies. We show how pervasive it is throughout the world, and that it is mostly associated with croplands. Atmospheric Physics Chemistry and Climate 2012-08-24 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.71/title.global-scale-attribution-of-anthropogenic-and-natural-dust-sources-and-their-emission-rates-based-on-modis-deep-blue-aerosol-products Dust is one of the most abundant aerosols in the atmosphere, and by scattering and absorbing solar radiation, it affects climate. In particular, anthropogenic dust is a significant source of radiative forcing on the climate system. Increasing numerical resolution of climate models provides an opportunity to create a realistic, high-resolution dust-source inventory. Atmospheric Physics Chemistry and Climate 2012-08-17 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.70/title.global-calcite-cycling-constrained-by-sediment-preservation-controls The primary objective of this work was to build a set of internally consistent and computationally efficient algorithms to represent the regionally varying production, water column dissolution, and sediment preservation of pelagic calcite, and analyze the biogeochemical implications. Climate and Ecosystems 2012-08-10 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.69/title.northern-high-latitude-heat-budget-decomposition-and-transient-warming The future response of Atlantic meridional overturning circulation (AMOC) to increased carbon dioxide is known to be uncertain, with models showing 21st century weakening of 0 to 50%, according to the IPCC 4th report. Climate Change Variability and Prediction 2012-08-03 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.68/title.evaluation-of-cloud-and-water-vapor-simulations-in-cmip5-climate-models-using-nasa-a-train-satellite-observations Clouds and water vapor are among the difficult features of the atmosphere for global climate models to simulate because they are affected by physical processes that operate over very small areas compared to the weather patterns that the models explicitly calculate. The authors used satellite data to assess the representation of clouds and water vapor simulated by several climate models that will participate in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). Atmospheric Physics Chemistry and Climate 2012-07-23 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.67/title.nonlinear-climate-response-to-regional-brightening-of-tropical-marine-stratocumulus To combat global warming, there have been suggestions to increase the albedo of (i.e. brighten) low-level marine clouds by deliberately injecting them with aerosols. Though such cloud seeding could mitigate global-mean temperature rise through the aerosol indirect effects, the full climate response to this geoengineering scheme is poorly understood. For example, one prior simulation of cloud seeding exhibited catastrophic rainfall decrease over the Amazon, while another showed moderate rainfall increase there. Atmospheric Physics Chemistry and Climate 2012-07-16 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.65/title.biases-in-the-atlantic-itcz-in-seasonal-interannual-variations-for-a-coarse-and-a-high-resolution-coupled-climate-model Using two fully coupled ocean-atmosphere GFDL models, CM2.1 and CM2.5 (a new high-resolution climate model based on CM2.1), the characteristics and sources of SST and precipitation biases associated with the Atlantic ITCZ were investigated and compared. CM2.5 has an improved simulation of the annual mean and the annual cycle of the rainfall over the Sahel and the northern South America, while CM2.1 shows excessive Sahel rainfall and lack of northern South America rainfall in boreal summer. Climate Change Variability and Prediction 2012-07-09 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.62/title.projected-response-of-an-endangered-marine-turtle-population-to-climate-change Assessing the potential impacts of climate change on individual species and populations is essential for the stewardship of ecosystems and biodiversity. Marine turtles must lay eggs in sandy beaches and thus climate change can affect both their marine and terrestrial habitat. The population of critically endangered eastern Pacific leatherback turtles (Dermochelys coriacea) nesting on the northwest coast of Costa Rica has been studied in terms of its sensitivity to contemporary climate variability in the nesting beach and ocean. Climate and Ecosystems 2012-07-01 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.64/title.physical-processes-that-impact-the-evolution-of-global-mean-sea-level-in-ocean-climate-models Global mean sea level reflects the combined effects of the total mass of seawater and its global mean density. Adding to the net seawater mass, as from melting land ice, raises sea level. Likewise, lowering seawater density, as when water is heated, raises sea level through so-called steric effects. Oceans and Climate 2012-06-08 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.63/title.model-precipitation-bias-over-the-southwestern-equatorial-indian-ocean This study investigated the spatio-temporal features of the serious positive precipitation bias over the southwestern equatorial Indian Ocean which is found in most current coupled and uncoupled general circulation models, and its links with the large scale monsoon circulation. The study attempted to answer two questions: Is there a common identifiable mechanism forcing the local bias? Does the local bias have an influence on the continental simulated monsoon precipitation? Atmospheric Physics Chemistry and Climate 2012-06-01 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.59/title.an-integrated-end-to-end-model-for-climate-fish-interactions Climate impacts on marine ecosystems arise from a combination of direct influences of physical climate on organisms (e.g., temperature effects on metabolic process) and indirect effects controlled by interactions with directly affected organisms. Indirect influences may originate with primary producers (i.e., phytoplankton) and propagate upward from the bottom of the food web or with higher trophic levels (i.e., fish) and propagate downward. Elucidating and predicting the response of living marine resources to climate and fishing pressure thus requires movement toward models that resolve interactions spanning physics to fish in an integrated way. Climate and Ecosystems 2012-05-18 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.58/title.21st-century-projections-of-north-atlantic-tropical-storms-from-cmip5-models North Atlantic tropical storms (TS) are a major climate hazard to North America, and have exhibited variability and change on decadal timescales. Therefore, understanding and predicting future decadal TS activity on decadal timescales is central to NOAA's mission and highly relevant to society. Climate Change Variability and Prediction 2012-05-14 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.61/title.tropical-tropospheric-only-responses-to-absorbing-aerosols An ongoing challenge in quantifying aerosols’ impact on the climate is determining an optimal way of calculating aerosols’ radiative forcing. For absorbing aerosols, in particular, studies have shown that a forcing calculation that does not include the tropospheric response to absorbing aerosol (instantaneous forcing) is a poor proxy for the change in global mean surface temperature caused by the aerosol. Atmospheric Physics Chemistry and Climate 2012-05-04 http://oldspiderwort.gfdl.noaa.gov/index/news-app/story.60/title.comparing-global-atmospheric-model-simulations-of-tropical-convection An intercomparison of global atmospheric model simulations of tropical convection has been presented and evaluated with available observations collected during the TWP-ICE field experiment. Short simulations initialized from the ECMWF analysis have been used to constrain model large-scale states and thus isolate model systematic biases originating from various physical parameterizations. With realistic thermodynamic and kinematic fields captured in various weather regimes (wet, dry, and break), model precipitation, cloud properties (LWC, IWC, cloud fraction), radiation, and vertical heating profiles respond accordingly in these regimes. Despite somewhat realistically simulated precipitation, there are substantial cloud property discrepancies among the models, which are mainly influenced by cloud and convective parameterizations. Atmospheric Physics Chemistry and Climate 2012-04-27