The sea ice surface is thought to be a major source of sea salt aerosol, suggesting that sodium records of polar ice cores may trace past sea ice extent. Here we test this possibility for the Arctic, using a chemical transport model to simulate aerosol emission, transport, and deposition in the satellite era. Our simulations suggest that sodium records from inland Greenland ice cores are strongly influenced by the impact of meteorology on aerosol transport and deposition. In contrast, sodium in coastal Arctic cores is predominantly sourced from the sea ice surface and the strength of these aerosol emissions controls the ice core sodium variability. Such ice cores may therefore record decadal to centennial scale Holocene sea ice changes. However, any relationship between ice core sodium and sea ice change may depend on how sea ice seasonality impacts sea salt emissions. Field‐based observations are urgently required to constrain this.
Apr 5, 2006 (CIDRAP News) – Cooking poultry to a temperature of 165°F will ensure it is safe to eat, though higher heat may be desirable for the sake of taste or appearance, the US Department of Agriculture (USDA) announced today.Current federal recommendations list various safe cooking temperatures for poultry, including 180°F for whole chickens and 170°F for breasts. The USDA said it wants to clarify that the key temperature for safety is 165°F. The guideline is based on advice from the USDA’s National Advisory Committee on Microbiological Criteria for Foods (NACMCF).”The Committee was asked to determine a single minimum temperature for poultry at which consumers can be confident that pathogens and viruses will be destroyed,” USDA Under Secretary for Food Safety Dr. Richard Raymond said in a news release.”The recommendation is based on the best scientific data available and will serve as a foundation for our programs designed to reduce foodborne illness and protect public health,” Raymond said.Heating to 165°F destroys Salmonella, “the most heat resistant pathogen of public health concern in raw poultry,” states an NACMCF report issued in March. The temperature is also lethal for Campylobacter bacteria and avian influenza viruses, the USDA said.But the USDA announcement says that consumers, “for reasons of personal preference, may chose to cook poultry to higher temperatures.”The committee report explains, “Guidance to the consumer should indicate that higher final temperatures may be needed for consumer acceptability and palatability (e.g., 170°F for whole muscle breast meat, 180°F for whole muscle thigh meat in order to remove the pink appearance and rubbery texture).”The temperature guideline is one of several recommendations the advisory committee made about safe cooking of poultry products. The USDA asked for advice after several people in Minnesota and Michigan contracted Salmonella infections last year from eating chicken products that appeared to be cooked but were not. The products were chicken breasts covered with browned breading.Among its other recommendations, the advisory committee said:Consumer guidelines should explain that longer cooking is needed if a product is frozen at the beginning of cooking.Consumers should be told that microwave cooking of raw, frozen poultry products is not advisable unless the package gives detailed instructions for determining if the product has reached the recommended temperature.Guidelines should address how to measure product temperature accurately and how to determine if a thermometer is “out of calibration.”Product labels should make clear whether the product is “ready to eat” or not.When a product containing raw poultry appears to be cooked, the label should make clear that it contains raw poultry and requires thorough cooking.See also:NACMCF draft reporthttp://www.fsis.usda.gov/shared/PDF/NACMCF_Report_Safe_Cooking_Poultry_032406.pdfCooking temperatures chart on federal “foodsafety.gov” sitehttp://foodsafety.gov/keep/charts/mintemp.htmlApr 22, 2005, CIDRAP News story “Salmonella cases linked to frozen chicken entrees” read more