Time filter

Source Type

Seattle, WA, United States

The National Oceanic and Atmospheric Administration is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere. NOAA warns of dangerous weather, charts seas and skies, guides the use and protection of ocean and coastal resources, and conducts research to improve understanding and stewardship of the environment. In addition to its civilian employees, 12,000 as of 2012, NOAA research and operations are supported by 300 uniformed service members who make up the NOAA Commissioned Officer Corps. The current Under Secretary of Commerce for Oceans and Atmosphere at the Department of Commerce and the agency's administrator is Kathryn D. Sullivan, who was nominated February 28, 2013, and confirmed March 6, 2014. Wikipedia.

Akmaev R.A.,National Oceanic and Atmospheric Administration
Reviews of Geophysics | Year: 2011

At the turn of the century R. G. Roble advanced an ambitious program of developing an atmospheric general circulation model (GCM) extending from the surface to the exosphere. He outlined several areas of research and application to potentially benefit from what is now commonly called whole atmosphere modeling. The purpose of this article is to introduce this new field to a broader geophysical community and document its progress over the last decade. Vertically extended models are commonly built from existing weather and climate GCM codes incorporating a number of approximations, which may no longer be valid. Promising directions of further model development, potential applications, and challenges are outlined. One application is space weather or day-to-day and seasonal variability in the ionosphere and thermosphere driven by meteorological processes from below. Various modes of connection between the lower and upper atmosphere had been known before, but new and sometimes unexpected observational evidence has emerged over the last decade. Persistent "nonmigrating" wavy structures in plasma and neutral densities and a dramatic response of the equatorial ionosphere to sudden warmings in the polar winter stratosphere are just two examples. Because large-scale meteorological processes are predictable several days in advance, whole atmosphere weather prediction models open an opportunity for developing a real forecast capability for space weather. © 2011 by the American Geophysical Union. Source

Winton M.,National Oceanic and Atmospheric Administration
Journal of Climate | Year: 2011

The sensitivity of Northern Hemisphere sea ice cover to global temperature change is examined in a group of climate models and in the satellite-era observations. The models are found to have well-defined, distinguishable sensitivities in climate change experiments. The satellite-era observations show a larger sensitivity-a larger decline per degree of warming-than any of the models. To evaluate the role of natural variability in this discrepancy, the sensitivity probability density function is constructed based upon the observed trends and natural variability of multidecadal ice cover and global temperature trends in a long control run of the GFDL Climate Model, version 2.1 (CM2.1). This comparison shows that the model sensitivities range from about 1 to more than 2 pseudostandard deviations of the variability smaller than observations indicate. The impact of natural Atlantic multidecadal temperature trends (as simulated by the GFDL model) on the sensitivity distribution is examined and found to be minimal. © 2011 American Meteorological Society. Source

Andersson A.J.,University of California at San Diego | Gledhill D.,National Oceanic and Atmospheric Administration
Annual Review of Marine Science | Year: 2013

The persistence of carbonate structures on coral reefs is essential in providing habitats for a large number of species and maintaining the extraordinary biodiversity associated with these ecosystems. As a consequence of ocean acidification (OA), the ability of marine calcifiers to produce calcium carbonate (CaCO3) and their rate of CaCO3 production could decrease while rates of bioerosion and CaCO3 dissolution could increase, resulting in a transition from a condition of net accretion to one of net erosion. This would have negative consequences for the role and function of coral reefs and the eco-services they provide to dependent human communities. In this article, we review estimates of bioerosion, CaCO3 dissolution, and net ecosystem calcification (NEC) and how these processes will change in response to OA. Furthermore, we critically evaluate the observed relationships between NEC and seawater aragonite saturation state (Omegaa). Finally, we propose that standardized NEC rates combined with observed changes in the ratios of dissolved inorganic carbon to total alkalinity owing to net reef metabolism may provide a biogeochemical tool to monitor the effects of OA in coral reef environments. © 2013 by Annual Reviews. All rights reserved. Source

Dunion J.P.,National Oceanic and Atmospheric Administration
Journal of Climate | Year: 2011

The Jordan mean tropical sounding has provided a benchmark reference for representing the climatology of the tropical North Atlantic and Caribbean Sea atmosphere for over 50 years. However, recent observations and studies have suggested that during the months of the North Atlantic hurricane season, this region of the world is affected by multiple air masses with very distinct thermodynamic and kinematic characteristics. This study examined;6000 rawinsonde observations from the Caribbean Sea region taken during the core months (July-October) of the 1995-2002 hurricane seasons. It was found that single mean soundings created from this new dataset were very similar to C. L. Jordan's 1958 sounding work. However, recently developed multispectral satellite imagery that can track low- to midlevel dry air masses indicated that the 1995-2002 hurricane season dataset (and likely Jordan's dataset as well) was dominated by three distinct air masses: moist tropical (MT), Saharan air layer (SAL), and midlatitude dry air intrusions (MLDAIs). Findings suggest that each sounding is associated with unique thermodynamic, kinematic, stability, and mean sea level pressure characteristics and that none of these soundings is particularly well represented by a single mean sounding such as Jordan's. This work presents three new mean tropical soundings (MT, SAL, and MLDAI) for the tropical North Atlantic Ocean and Caribbean Sea region and includes information on their temporal variability, thermodynamics, winds, wind shear, stability, total precipitable water, and mean sea level pressure attributes. It is concluded that the new MT, SAL, andMLDAIsoundings presented here provide a more robust depiction of the tropical North Atlantic and Caribbean Sea atmosphere during the Atlantic hurricane season and should replace the Jordan mean tropical sounding as the new benchmark soundings for this part of the world. © 2011 American Meteorological Society. Source

Waples R.S.,National Oceanic and Atmospheric Administration
Proceedings. Biological sciences / The Royal Society | Year: 2013

Effective population size (Ne) controls both the rate of random genetic drift and the effectiveness of selection and migration, but it is difficult to estimate in nature. In particular, for species with overlapping generations, it is easier to estimate the effective number of breeders in one reproductive cycle (Nb) than Ne per generation. We empirically evaluated the relationship between life history and ratios of Ne, Nb and adult census size (N) using a recently developed model (agene) and published vital rates for 63 iteroparous animals and plants. Nb/Ne varied a surprising sixfold across species and, contrary to expectations, Nb was larger than Ne in over half the species. Up to two-thirds of the variance in Nb/Ne and up to half the variance in Ne/N was explained by just two life-history traits (age at maturity and adult lifespan) that have long interested both ecologists and evolutionary biologists. These results provide novel insights into, and demonstrate a close general linkage between, demographic and evolutionary processes across diverse taxa. For the first time, our results also make it possible to interpret rapidly accumulating estimates of Nb in the context of the rich body of evolutionary theory based on Ne per generation. Source

Discover hidden collaborations