A nonlocal observation operator has been developed to assimilate GPS radio occultation (RO) refractivity with WRF 3DVAR. For simplicity. in the past GPS RO refractivity was often assimilated using a local observation operator with the assumption that the GPS RO observation was representative of amodel local point. Such an operator did not take into account the effects of horizontal in... https://shopredoners.shop/product-category/cropped-oversized-button-up/