This is a painting of Aya Sofya in Istanbul - Rain over St. Sophia, 1920 - by Oleksa Hryshchenko (1883-1977). Below is part of his bio - and you can read more about his life and see more of his work here (link via Lynn S from Reflections in d minor):
During the Russian Revolution, Hryshchenko became professor at the State Art Studios in Moscow and a member of the Commission for the Protection of Historic Monuments. He was offered the directorship of the Tretiakov Gallery, but in 1919, not wishing to became a state functionary, he escaped by way of Crimea to Constantinople, leaving all his paintings and other possessions in Moscow. In the Turkish capital, he lived a life of extreme poverty, but never ceased to paint and his watercolors of that period soon made his name famous in the art world of the twenties. He made the acquaintance of the American archeologist and collector Thomas Wittnore, of Boston, the restorer of St. Sophia, who acquired 66 of his water colors. This enabled Hryshchenko to make a trip to Greece where he painted in Mistra, Delphi, Corinth and Olympia. In 1921, when he came to Paris, 12 of his Constantinople paintings were accepted by the Salon d'Automne, and Fernand Leger placed them next to his own works.