Overview: The Stratospheric Photochemistry Aerosols and Dynamics Expedition (SPADE) and Airborne Arctic Stratospheric Expedition II (AASE-II)

Journal Article · Tue Nov 15 04:00:00 EST 1994 · Geophysical Research Letters

DOI:https://doi.org/10.1029/94GL02839· OSTI ID:57029

Wofsy, S C; Cohen, R C ^[1]; Schmeltekopf, A L

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1. Harvard Univ., Cambridge, MA (United States)

The Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE) made in situ observations of the composition of the lower stratosphere from the NASA ER-2 aircraft at latitudes from 15{degrees}N to 60{degrees}N, during November 1992 and April, May and October 1993. SPADE followed the Airborne Arctic Stratospheric Expedition II (AASW-II, September 1991 to March 1992) by 8 months. Together the two missions provide a record of stratospheric trace species and aerosols at middle and high latitudes spanning the input and decay of debris from the eruption of Mt. Pinatubo. New instruments deployed for SPADE include sensors to measure OH, HO{sub 2} H{sub 2}O, CO{sub 2}, NO{sub 2} and the UV/visible radiation field, complementing sensors previously deployed on the ER-2 (ClO, BrO, NO, NO{sub y}, N{sub 2}O, O{sub 3}, H{sub 2}O, HCl, CH{sub 4}, CFC-11, CFC-113, and aerosol number and size distribution). The data provide the first simultaneous in situ measurements of radicals and reservoir species to include representatives from all the important families of stratospheric reactants, observed as functions of time of day (at {approx}18 km), latitude and altitude (15-20 km). The results place strong new constraints on models of stratospheric photochemistry. For example, measurements of the radicals HO{sub 2}, NO{sub 2}, ClO, and BrO allow for a nearly completely empirical evaluation of local rates for photochemical removal of ozone (by known catalytic cycles).

• OSTI ID: 57029
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 23 Vol. 21; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BROMINE OXIDES
CARBON DIOXIDE
CHLORINE OXIDES
DAILY VARIATIONS
ECOLOGICAL CONCENTRATION
FREONS
HYDROCHLORIC ACID
HYDROXYL RADICALS
METHANE
NITRIC OXIDE
NITROGEN OXIDES
NITROUS OXIDE
OZONE
STRATOSPHERE
WATER VAPOR