The radiation budget of the atmosphere over the Arctic compiled from the ISCCP-FD data sets (preliminary results)

The technological advancements of the past two to three decades enabled the establishment of space-borne observational systems to measure worldwide clouds and related radiation fields at the top of the atmosphere. This data when combined with further information on the thermodynamic state of the atmosphere and ground allows for estimates of the radiation budget at ground and within the atmosphere. This information is urgently required to calibrate the output of climate models and to understand current changes in the climate system. Results of the International Satellite Cloud Climatology Project (ISCCP) are here presented and compared with another but similar data set of the Global Energy and Water Cycle Experiment (GEWEX-SRB) and with ground-based measurements. This data describes details in space and time of the variability of radiation budget parameters at the surface and at the top of the atmosphere over the entire globe. Over the Arctic ice fields-our studies concern areas poleward of about 60°N-considerable uncertainties of more than 20Wm^(-2) still exist in both the long-wave and short-wave budget components at ground

In-situ measurement of the ozone concentration in the Arctic Airborne Measurement Program 2002(AAMP02)

From 5 to 14 March, 2002, the Arctic Airborne Measurement Program 2002(AAMP02) was conducted on a round-trip flight between Nagoya, Japan, and Longyearbyen, Svalbard, via Anchorage and Barrow, U.S.A. and the North Pole using a chartered twin-jet aircraft, the Gulfstream-II(G-II). On board the G-II, in-situ measurements of the ozone concentration were carried out every 12s in order to obtain information on air mass differences and advection. Vertical profiles of the ozone concentration observed over Longyearbyen agreed well with those observed by ozone sonde launched around the same time from Ny-Ålesund, about 100km north of Longyearbyen. The ozone variations observed in the upper troposphere and lower stratosphere showed negative correlation with the CO_2 concentration, suggesting vertical displacements of air masses. However, it was also observed that the ozone concentration fluctuated considerably with little consistency with the meteorological field

Lower tropospheric vertical distribution of aerosol particles over Syowa Station, Antarctica from spring to summer 2004

Vertical distributions of atmospheric aerosol particles were measured nine times up to 5200 m a.s.l. using an aircraft over Syowa Station, East Antarctica during September-December 2004. Measurements were made for number concentrations of condensation nuclei (CN, Dp>10 nm), number-size distribution larger than 0.3 μm diameter, air temperature, humidity, and GPS position. During spring, the vertical profile of CN concentration showed large variability (100-1000 cm^(-3)), but it was mostly constant in summer. Vertical profiles of number-size distribution larger than 0.3 μm showed a systematic shift at altitudes greater than 4000 m. Both concentrations of aerosol number for Dp>0.3 μm and integrated volume between 0.3 and 1.0 μm showed constantly lower values at altitudes greater than 4000 m. These data suggest that the shift of aerosol parameters results from depletion of coarse particles such as sea salts. Maximum concentrations of the volume and CN were obtained respectively from the profiles on 7 October and 29 November 2004. These events are interpreted as sources and transport processes based on synoptic meteorological data, an ocean color index produced by SeaWiFS, and backward air trajectory analysis

In-situ measurement of the atmospheric CO concentration at Syowa Station, Antarctica

A high-precision measurement system for the atmospheric CO concentration was developed. With some modifications to a gas chromatograph CO analyzer, instrumental reproducibility of 0.5 ppbv was achieved. This could be sufficient for detection of short-term, seasonal and long-term variations of the atmospheric CO concentration in the Antarctic region. A standard gas system to maintain a consistent calibration scale for the CO measurements was also prepared. The measurement system was installed at Syowa Station in March 2000 and has been maintained up to the present. The first-year\u27s observation showed a clear seasonal cycle of CO concentration