diff --git a/src/grib_iterator_class_polar_stereographic.c b/src/grib_iterator_class_polar_stereographic.c
index 1a29fd567..d8c734b18 100644
--- a/src/grib_iterator_class_polar_stereographic.c
+++ b/src/grib_iterator_class_polar_stereographic.c
@@ -134,60 +134,66 @@ static int init(grib_iterator* iter, grib_handle* h, grib_arguments* args)
 
     grib_iterator_polar_stereographic* self = (grib_iterator_polar_stereographic*)iter;
 
-    const char* sradius                 = grib_arguments_get_name(h, args, self->carg++);
-    const char* snx                     = grib_arguments_get_name(h, args, self->carg++);
-    const char* sny                     = grib_arguments_get_name(h, args, self->carg++);
-    const char* slatFirstInDegrees      = grib_arguments_get_name(h, args, self->carg++);
-    const char* slonFirstInDegrees      = grib_arguments_get_name(h, args, self->carg++);
-    const char* ssouthPoleOnPlane       = grib_arguments_get_name(h, args, self->carg++);
-    const char* scentralLongitude       = grib_arguments_get_name(h, args, self->carg++);
-    const char* scentralLatitude        = grib_arguments_get_name(h, args, self->carg++);
-    const char* sDx                     = grib_arguments_get_name(h, args, self->carg++);
-    const char* sDy                     = grib_arguments_get_name(h, args, self->carg++);
-    const char* siScansNegatively       = grib_arguments_get_name(h, args, self->carg++);
-    const char* sjScansPositively       = grib_arguments_get_name(h, args, self->carg++);
-    const char* sjPointsAreConsecutive  = grib_arguments_get_name(h, args, self->carg++);
-    const char* salternativeRowScanning = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_radius                 = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_nx                     = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_ny                     = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_latFirstInDegrees      = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_lonFirstInDegrees      = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_southPoleOnPlane       = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_centralLongitude       = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_centralLatitude        = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_Dx                     = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_Dy                     = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_iScansNegatively       = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_jScansPositively       = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_jPointsAreConsecutive  = grib_arguments_get_name(h, args, self->carg++);
+    const char* s_alternativeRowScanning = grib_arguments_get_name(h, args, self->carg++);
 
     if (grib_is_earth_oblate(h)) {
         grib_context_log(h->context, GRIB_LOG_ERROR, "Polar stereographic only supported for spherical earth.");
         return GRIB_GEOCALCULUS_PROBLEM;
     }
 
-    if ((ret = grib_get_double_internal(h, sradius, &radius)) != GRIB_SUCCESS)
+    if ((ret = grib_get_double_internal(h, s_radius, &radius)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, snx, &nx)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_nx, &nx)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, sny, &ny)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_ny, &ny)) != GRIB_SUCCESS)
         return ret;
 
     if (iter->nv != nx * ny) {
         grib_context_log(h->context, GRIB_LOG_ERROR, "Wrong number of points (%ld!=%ldx%ld)", iter->nv, nx, ny);
         return GRIB_WRONG_GRID;
     }
-    if ((ret = grib_get_double_internal(h, slatFirstInDegrees, &latFirstInDegrees)) != GRIB_SUCCESS)
+    if ((ret = grib_get_double_internal(h, s_latFirstInDegrees, &latFirstInDegrees)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_double_internal(h, slonFirstInDegrees, &lonFirstInDegrees)) != GRIB_SUCCESS)
+    if ((ret = grib_get_double_internal(h, s_lonFirstInDegrees, &lonFirstInDegrees)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, ssouthPoleOnPlane, &southPoleOnPlane)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_southPoleOnPlane, &southPoleOnPlane)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, scentralLongitude, &centralLongitudeInDegrees)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_centralLongitude, &centralLongitudeInDegrees)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, scentralLatitude, &centralLatitudeInDegrees)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_centralLatitude, &centralLatitudeInDegrees)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_double_internal(h, sDx, &Dx)) != GRIB_SUCCESS)
+    if ((ret = grib_get_double_internal(h, s_Dx, &Dx)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_double_internal(h, sDy, &Dy)) != GRIB_SUCCESS)
+    if ((ret = grib_get_double_internal(h, s_Dy, &Dy)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, sjPointsAreConsecutive, &jPointsAreConsecutive)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_jPointsAreConsecutive, &jPointsAreConsecutive)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, sjScansPositively, &jScansPositively)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_jScansPositively, &jScansPositively)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, siScansNegatively, &iScansNegatively)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_iScansNegatively, &iScansNegatively)) != GRIB_SUCCESS)
         return ret;
-    if ((ret = grib_get_long_internal(h, salternativeRowScanning, &alternativeRowScanning)) != GRIB_SUCCESS)
+    if ((ret = grib_get_long_internal(h, s_alternativeRowScanning, &alternativeRowScanning)) != GRIB_SUCCESS)
         return ret;
 
+    if (alternativeRowScanning) {
+        grib_context_log(h->context, GRIB_LOG_ERROR, "Polar stereographic not supported when alternativeRowScanning=1 "
+                                                     "i.e., When adjacent rows scan in the opposite direction");
+        return GRIB_GEOCALCULUS_PROBLEM;
+    }
+
     centralLongitude = centralLongitudeInDegrees * DEG2RAD;
     centralLatitude  = centralLatitudeInDegrees * DEG2RAD;
     lonFirst         = lonFirstInDegrees * DEG2RAD;