Measurement and interpretation of concentrations of H2O2 and related species in the upper midwest during summer
Measurement and interpretation of concentrations of H2O2 and related species in the upper midwest during summer
复制标题
夏季中西部上部 H2O2 和相关物种浓度的测量和解释
DOI：
10.1029/jd095id07p09857
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
J. Boatman
中科院分区：
文献类型：
--
作者：
P. Daum;L. Kleinman;A. Hills;A. Lazrus;A. Leslie;K. M. Busness;J. Boatman
1987年6月，在俄亥俄州上空，用飞机在11天内进行了18次飞行，测量了H2O2和相关物质。测量通常包括从地表到平均海平面以上5.5公里的高度范围，并在各种气象条件下进行，但重点是有利于对流风暴形成的条件。H2O2的浓度范围从<0.2到7 ppb，即使在固定海拔的某一天，以及几天之间，也表现出高达10倍的变化。过氧化氢浓度在地表附近低，在边界层顶部附近达到最大值，然后随高度缓慢下降。相比之下，SO2和NOy主要局限于表层。一个简单的光化学计算表明，在NOx浓度较低的地方，[H2O2]受到水蒸气浓度的强烈影响。[H2O2]跟踪露点的变化，测量和计算的H2O2浓度基本一致。边界层中[H2O2]的低是由于除组合反应外的其他反应对自由基的消耗，以及干沉积造成的H2O2的损失。对H2O2和SO2的剖面形状的比较表明，混合过程将对这两种物质在对流系统中的反应程度产生很大影响。
Measurements of H2O2 and related species were made by aircraft on 18 flights over 11 days during June 1987 over Ohio. Measurements typically encompassed an altitude range from the surface to 5.5 km above mean sea level and were conducted under a variety of meteorological conditions, but focussed on conditions conducive to the formation of convective storms. Concentrations of H2O2 ranged from <0.2 to 7 ppb and exhibited as much as a factor of 10 variability even on a given day at fixed altitude, as well as between days. Hydrogen peroxide concentration typically was low near the surface, rose to a maximum near the top of the boundary layer, then slowly decreased with altitude. In contrast, SO2 and NOy were largely confined to the surface layer. A simple photochemical calculation shows that where NOx concentrations are low, [H2O2] is strongly influenced by the water vapor concentration. The [H2O2] tracked changes in dew point, and measured and calculated H2O2 concentrations were in general agreement. The low [H2O2] in the boundary layer is ascribed to consumption of radicals by reactions other than combination reactions, and to loss of H2O2 by dry deposition. Comparison of the profile shapes for H2O2 and SO2 suggests that mixing processes will have a large influence on the extent to which these two species will react in convective systems.