Stifling summers forecast by NASA for US east coast

[arenean]

From The Independent:

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Researchers at Nasa have warned that unless growth in greenhouse gas emissions can be successfully curbed, large areas of the eastern United States, from Washington DC to Florida, can expect to suffer through catastrophically hotter summers within just a couple of generations.

A study released by Nasa's Goddard Institute for Space Studies at Columbia University finds that by 2080 average summer high temperatures in parts of the east will be about 10F higher than now, pushing them from the low to mid-80s to the low to mid-90s.

Moreover, in particularly dry years with only limited rainfall to cool conditions, average high temperatures in cities as far apart as Atlanta, Washington DC and even Chicago to the north could peak at a baking 110F roughly the kinds of readings seen today only in the desert south-west.

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Complete article here:

Stifling summers forecast by NASA for US east coast

[Viking12]

1. Abstract and link to actual paper

Lynn, B.H., R. Healy, and L.M. Druyan, 2007: An analysis of the potential for extreme temperature change based on observations and model simulations. J. Climate, 20, 1539-1554, doi:10.1175/JCLI4219.1.

The study analyzes observational climate data for June-August 1977-2004 and simulations of current and future climate scenarios from a nested GCM/regional climate model system to assess the potential for extreme temperature change over the eastern United States. Observational evidence indicates that anomalously warm summers in the eastern United States coincide with anomalously cool eastern Pacific sea-surface temperatures, conditions that are conducive to geopotential ridging over the east, less frequent precipitation and lower accumulated rainfall. The study also found that days following nighttime rain are warmer on average than daytime rain events, emphasizing the importance of the timing of precipitation on the radiation balance. Precipitation frequency and eastern Pacific sea-surface temperature anomalies together account for 57% of the 28- year variance in maximum surface temperature anomalies. Simulation results show the sensitivity of maximum surface air temperature to the moist convection parameterization that is employed, since different schemes produce different diurnal cycles and frequencies of precipitation. The study suggests that, in order to accurately project scenarios of extreme temperature change, models need to realistically simulate changes in the surface energy balance caused by the interannual variation of these precipitation characteristics. The mesoscale model that was realistic in this respect predicted much warmer mean and maximum surface air temperatures for five future summers than the parallel GCM driving simulation.


http://pubs.giss.nasa.gov/abstracts/2007/Lynn_etal.html