We present Atacama Large Millimeter/submillimeter Array (ALMA) and Very Large Array (VLA) spatial maps of the Uranian atmosphere taken between 2015 and 2018 at wavelengths from 1.3 mm to 10 cm, probing pressures from ∼1 to ∼50 bar at spatial resolutions from 0.″1 to 0.″8. Radiative transfer modeling was performed to determine the physical origin of the brightness variations across Uranus’s disk. The radio-dark equator and midlatitudes of the planet (south of ∼50N) are well fit by a deep H₂S mixing ratio of ( solar) and a deep NH₃ mixing ratio of ( solar), in good agreement with models of Uranus’s disk-averaged spectrum from the literature. The north polar region is very bright at all frequencies northward of ∼50N, which we attribute to strong depletions extending down to the NH₄SH layer in both NH₃ and H₂S relative to the equatorial region; the model is consistent with an NH₃ abundance of and an H₂S abundance of <1.9נ10⁻⁷ between ∼20 and ∼50 bar. Combining this observed depletion in condensible molecules with methane-sensitive near-infrared observations from the literature suggests large-scale downwelling in the north polar vortex region from ∼0.1 to ∼50 bar. The highest-resolution maps reveal zonal radio-dark and radio-bright bands at 20S, 0, and 20N, as well as zonal banding within the north polar region. The difference in brightness is a factor of ∼10 less pronounced in these bands than the difference between the north pole and equator, and additional observations are required to determine the temperature, composition, and vertical extent of these features.

我们展示了2015年至2018年之间在1.3 mm至10 cm波长下拍摄的阿塔卡马大毫米/亚毫米阵列（ALMA）和超大阵列（VLA）空间图，在空间分辨率下探测了约1至约50 bar的压力从0.“ 1到0.” 8。进行了辐射转移建模，以确定整个天王星盘亮度变化的物理原因。行星（南~50N的）的电波暗赤道和纬度是公通过深ħ适合_2个小号混合的比率（太阳能）和深NH ₃的混合比（太阳），与文献中的天王星盘平均光谱模型非常吻合。北极地区在〜50N以北的所有频率处都非常明亮，这归因于相对于赤道区域，在NH ₃和H ₂ S中向下延伸至NH ₄ SH层的强烈耗尽。该模型与NH ₃丰度和H ₂ S丰度<1.9נ10 ^-7相一致在约20至约50巴之间。将可观察到的可压缩分子的消耗与对甲烷敏感的近红外观测相结合，表明在北极涡旋区从〜0.1 bar到〜50 bar发生了大规模下沉。最高分辨率的地图显示20S，0和20N处的纬向无线电暗带和无线电明亮带，以及北极地区的纬向带。在这些波段中，亮度差异比北极和赤道之间的差异低约10倍，并且还需要其他观察以确定这些特征的温度，组成和垂直范围。